centre of advanced studies in plant pathology - citeseerx

CCEENNTTRREE OOFF AADDVVAANNCCEEDD SSTTUUDDIIEESS

IINN

PPLLAANNTT PPAATTHHOOLLOOGGYY

(Indian Council of Agricultural Research, New Delhi)

Proceedings of the 20th

Training

on

““SSeeeedd HHeeaalltthh MMaannaaggeemmeenntt ffoorr BBeetttteerr PPrroodduuccttiivviittyy””

MMaarrcchh 2288 ttoo AApprriill 1177,, 22000088

DDDrrr... JJJ... KKKuuummmaaarrr,,, DDDiiirrreeeccctttooorrr CCCAAASSS

DDDrrr... SSS...CCC... SSSaaaxxxeeennnaaa,,, CCCooouuurrrssseee CCCoooooorrrdddiiinnnaaatttooorrr

GG..BB.. PPAANNTT UUNNIIVVEERRSSIITTYY OOFF AAGGRRIICCUULLTTUURREE AANNDD TTEECCHHNNOOLLOOGGYY,,

PANTNAGAR- 263 145 (UTTARAK HAND)

PREFACE

Increase in agricultural production is the key to all-over economic growth.. In view of

increasing world population and escalating overall food requirements rapid growth of agriculture

is essential for ensuring food security and alleviating poverty. Growing demand must be met

primarily by increasing production on land already under cultivation and by reducing losses due to

diseases and pests. Seed constitutes the main propagule for plant growth and, at the same time,

one of the main vehicles for the dissemination of plant pests. Seed-borne pathogens, such as fungi,

bacteria and viruses are serious constraints to crop productivity. In worst-case scenario, seed-

borne diseases can be disastrous and even life threatening. Seed health testing and management

needs to be understood in light of general evolution of the seed sector. Estimation of losses

attributed to seed-borne inoculum, establishing predictive relationships between seed-borne

inoculum and disease incidence, developing reliable, effective, cheap and rapid detection methods,

dialogue with the private sector on development of test procedures, and comparing data on

advantages of seed health are the current issues. Besides, increasing crop productivity seed health

issues are exremely important in international seed trade and conservation and utilization of plant

genetic resources, which is vital for global food security.

To address this emerging challenge, the 20th

CAS training on ‘Seed Health Management for

Better Productivity’ was visualized. Excellent response was received from all over India for

participation in this training. Twenty one participants representing 12 states actively participated

in the programme for 21 days. They were exposed to the recent advances in seed health

management through lectures, practicals and field visits on seed health testing and quality seed

production. Scientific areas covered included series of lectures covering various aspects of

technological innovations with respect to seed and seed health, precision detection of seed borne

pathogens, storage pests and GMOs, transboundary movement of seed transmitted pests, seed

production, protection, and certification, PEQs, policy issues, etc

We are grateful to the ICAR for sponsoring this 20th

CAS training programme. We are

highly grateful to Prof. A.P. Sharma, Vice-Chancellor for his constant support, guidance and

encouragement in making the training a great success. We put on record the help and guidance

received from Dr. J.P. Tiwari, Dean Agriculture, Dr. D.P. Singh, Director Research and Dr. K. P.

Singh, Director Extension Education in the successful conduct of training programme. We

sincerely acknowledge the services of our guest speakers Dr. R.C. Sharma, Professor, Seed

Technology Centre, PAU, Ludhiana; Dr. A.K. Gaur, New Delhi; Dr. Y.P. Singh, Scientist, Forest

Pathology Division, Forest Research Institute, Dehradun; Dr. R.D. Kapoor, Regulatory Lead,

Monsanto India Ltd., New Delhi; Dr. O.K. Sinha, Principal Scientist & Coordinator (AICRP

Sugarcane), IISR, Lucknow; Dr. R.L. Agrawal, Lucknow, Dr. B.B.Singh, Visiting Professor, Texas

A&M, USA; Dr. U.S. Singh, IRRI, DElhi. We would be failing in our duty if we do not

acknowledge the help and logistic support received from Dr. S.K.Sharma, Director, NBPGR, Dr.

R.K. Khetrapal and his team of scientists for delivering lectures during exposure visit of

participants at NBPGR, New Delhi. Several scientists from various departments such as Soils

Science, Entomology, Genetics and Plant Breeding, Agric. Communication, Agronomy, Biological

Science, Molecular Biology & Genetic Engineering, Agrometeorology and the University library in

addition to Plant Pathology rendered all possible help and delivered scientific lectures. We

acknowledge their contributions with utmost gratitude and sincerity.

Pantnagar

April 17, 2008

S.C. Saxena

Course Coordinator

J. Kumar

Director, CAS

CONTENTS

Sl. No. Title Speaker Page

Welcome Address Dr. J. Kumar i-iii

Inaugural Address Dr. A.P. Sharma i-ii

1. Department of Plant Pathology Dr. J. Kumar 1-22

2. Priorities in Seed Pathology and Seed Health

Testing Research

Dr. (Mrs.) K.

Vishunavat

23-27

3. Epidemiological Approaches to Disease

Management through Seed Technology

Dr. (Mrs.) K.

Vishunavat

28-34

4. Seed Treatment–A New Challenge in Organic Seed

Production

Dr. R.L. Agarwal 35-36

5. Strategies for Regulation of Seed Borne Diseases

in Organic Farming

Dr. R.L. Agarwal 37-40

6. Seeds: Intellectual Property Dr. H.S. Chawla 41-46

7. Contribution of Uttaranchal Seeds & TDC in the

Prosperity of the Farmers

Dr. H.K. Singh 47

8. Quality Control Arrangements in the Seed

Production

Dr. Deepak Pande 48-49

9. Role of GBPUA & T in Agricultural Development

and Popularization of Seeds of New Varieties

Dr. S.C. Mani 50-52

10. Soil Health and Quality Seed Production Dr. B. Mishra 53-56

11. Agronomic Management of Seed Quality Dr. R.S. Verma 57-60

12. Post-Entry Quarantine Facilities and Requirements Dr. D.B. Parakh 61-64

13. Resource Conservation Techniques in Seed Crop

Health

Dr. K.P. Singh 65-74

14. Advances in Breeding and Seed Production

Techniques of Cucurbits

Dr. D. K. Singh 75-83

15. Integrated Disease Management for Vegetable

Seed Production

Dr. S.N.

Vishwakarma

84-86

16. Seed Cane Health for Sustaining Higher Sugarcane

Productivity

Dr. S.K. Saini 87-92

17. Approaches for Healthy Seed Production in

Sugarcane

Dr. O.K. Sinha 93-94

18. Detection of Smut and Red Rot Pathogens in

Sugarcane for Production of Healthy Seed

Dr. O.K. Sinha 95-96

19. Disease Free Seed Production of Cereals Dr. M.K. Nautiyal 97-102

i

20. Seed Health Management for Better Productivity in

Pulses

Dr. H.S. Tripathi 103-107

21. Role of Cultural Practices on the Management of

Seed Borne Diseases

Dr. R.P. Awasthi 108-111

22. Smuts, Bunts and Ergots their Significance and

Management in Seed Crop

Dr. R.C. Sharma 112-118

23. Ear Rot and Banded Leaf & Sheath Blight of Maize Dr. S.C. Saxena 119-123

24. Aflatoxin in Maize Dr. S.C. Saxena 124-129

25. Production of Quality Seed in Tree Species Dr. Salil Tewari 130-132

26. Management of Plant Propagating Material for

Quality Control in Forest Crops

Dr. P.R. Rajput 133-140

27. Management of Seed Borne Bacterial Diseases in

Seed Production Plots

Dr. Y. Singh 141-144

28. Seed Borne Diseases of Rice and their

Management

Dr. A.P. Sinha 145-155

29. Insect Pest Stored Seed and their Management Dr. S.N. Tewari 156-162

30. Nanotechnology in Diagnosis of Plant Diseases Dr. D.B. Parakh 163

31. Application of DNA Techniques in Seed Industry Dr. S. Marla 164-169

32. Role of Biotechnology in Improving Seed Health

Management

Dr. Anil Kumar 170-178

33. Seeds: The Tale of Biotechnology Dr. Anil Kumar 179-185

34. New Approaches to Pest Risk Analysis for

Quarantine Pests

Dr. Ruchira Tiwari 186-194

35. Communication Skills for Teaching Dr. B. Kumar 195-197

36. Seed Health Management in Potato Dr. V.S. Pundhir 198-200

37. Quality Spawn Production Dr. K.P.S. Kushwaha 201-203

38. Biointenssive IPM for Crop Disease Management

on Small Farms

Dr. J. Kumar 204-208

Valedictory Address Prof. A.P. Sharma i-ii

Annexure- I (Committee members) i-ii

Annexure- II (List of Participants) i-iii

Annexure- III (List of Speakers) i-ii

Annexure- IV (List of Training Course Schedule) i-v

ii

WELCOME ADDRESS by

Dr. J. Kumar Director CAS

Prof. & Head, Plant Pathology, College of Agriculture

G.B. Pant University of Agriculture & Technology, Pantnagar- 263 145

on

March 29, 2008

Good morning and welcome to the

Inaugural Session of the 20th CAS training on

“Seed Health Management for Better

Productivity”.

Hon’ble, Vice-Chancellor Dr. A.P.

Sharma; Dean Agriculture Dr. J.P. Tiwari; Dr.

D.P. Singh Director Experiment Station, Dr.

K.P. Singh, Director Extension, Dr. S.C.

Saxena, Course Coordinator of the present

training, Deans and Directors, Jt. Directors,

Officers, Heads of Departments, Senior faculty

members, Colleagues, Staff members, the

trainees from different universities, Students,

Press & Media, Ladies & Gentle men.

At the outset, on behalf of faculty of

Plant Pathology and on my own behalf, it is a

pleasure in welcoming the Chief Guest of the

function, honorable Dr. A.P. Sharma, Vice-

Chancellor of this University as well as

Director, Uttarakhand Seed Certification

Agency. Dr. Sharma, an accomplished

scientist and renowned expert in fisheries

science, winner of many awards and ex-Dean

college of Fisheries, is a big support and

source of inspiration for the pursuance of

research and academics in this Great

University besides leading the Uttarakhand

Seed Certification agency from the front. You

have consented to grace this occasion despite

your very hectic schedule of work, we are all

very grateful to you, Sir.

It is a pleasure in welcoming Dr. J. P.

Tiwari the Dean, College of Agriculture. Dr.

Tiwari is vastly experienced and has held

several important positions such as Head,

Department of Horticulture, Registrar, and

Dean, P.G.S. Dr. Tiwari has held college of

agriculture in high esteem. We all members of

Plant Pathology faculty welcome you sir.

I am also pleased to welcome Dr. D. P.

Singh, Director Experiment Station and

renowned Plant Breeder in the country, who

has developed a number of varieties of various

pulses that are widely grown in the country. Dr.

Singh has also held various other important

positions such as Dean PGS and Head of the

Department of Genetics & Plant Breeding . I

like to welcome you to this function, sir.

It is again a pleasure in welcoming Dr.

K.P. Singh, the Director Extension, who is

essentially a Plant Pathologist and has

tremendous experience in administration,

research and extension. He is a tremendous

support in establishing extension linkages and

registering our existence at the end of farming

community in the State.

I would also like to welcome Dr. S.C.

Saxena, one of the senior most persons in the

College and a guest faculty in the Department

of Plant Pathology. Dr. Saxena is the First

Generation Staff in the Department as well as

the College and is an appropriate interface to

i

the newer generations coming to the

Department.

I welcome our esteemed Registrar,

Deans and Directors, Jt. Directors, Officers

who are present here in the hall. They have

spared their valuable time to grace this

occasion.

The Heads and faculty members of

various departments have also responded to

our request and are present in the hall. I

welcome all of you to the function.

The participants of the training from

different universities have traveled a long

distance to reach Pantnagar. While at

Pantnagar you may miss the comforts and

attractions of big cities but the warmth of

academics that exist at this place and a very

exhaustive work that awaits you should keep

you engrossed and compensate for any

logistic inadequacies. I welcome you all and

assure you a comfortable stay within our

means.

In the last, but not the least, I welcome

all our students and staff, press and media and

others who are present in the hall and have

made the arrangements for this inaugural

session.

Ladies and gentlemen, the Department

of Plant Pathology was created and accredited

by ICAR in 1961 and ever since the

Department has had a strong commitment to,

and history of, sound education, research and

extension in Plant Pathology. Dr. Y.L.Nene

was the first Head of the Department. Under

his capable leadership, the department

expanded to include many dedicated faculty

members whose programmes made the

Department the recognized leader in the

country. The next generation of faculty

members like the first responded to the

changing needs presented by the modern

agriculture. At present the Department includes

14 professors, one senior professor as guest

faculty, one honourary professor from INRA,

France, four Associate Professors and two

Assistant Professors with 13 technical and 10

supporting staffs. The entire staff upholds the

Department’s commitment to education, basic

and applied research and extension

The Department has a well-knit under

graduate (U.G.) and post graduate (P.G.)

programme with updated and modern course

curricula. It offers six U.G. and 20 P.G.

courses. A broad range of carefully designed

courses complimented by lectures in other

Departments appropriately address the

academic needs of the students. The great

diversity of areas of expertise and interests

present in the Department leads to diversity in

thesis titles. So far 290 M.Sc. and 155 Ph.D.

students have earned degrees from the

Department.

The Department is actively engaged in

the research work on both fundamental and

applied aspects in the domains of ecology of

soil borne plant pathogens, epidemiology and

forecasting, biological control and IPM

including small farms technologies, molecular

diagnostics, pathogen population biology,

disease resistance, seed pathology,

fungicides, nematology, phytovirology,

phytobacteriology and biology & technology of

mushroom production.

The distinguished faculty of the

Department has brought in a number of

national and international research grants

besides a series of AICRPS. For a number of

AICRPs such as those of Rice, Wheat,

Oilseeds, Potato, Seeds and Small millets the

faculty members of the Department render

services as the Project Coordinators also.

ii

Over the years, the trained and

accomplished faculty members as well as

students in addressing current issues in Plant

Pathology have won over 40 national and

international awards. Individual staff members

with in the department have long been

recognized for their leadership role in the

science of Plant Pathology. By way of their

contributions many faculty members of the

Department have earned International

positions. Also a number of faculty members

have served as president, vice presidents, and

zonal president of several professional

societies

The Department has a unique

distinction of producing 35 books published by

not only Indian but also reputed international

publishers. This is besides a series of

technical bulletins, lab manuals, compendia

and extension literature that have also been

prepared.

The Department, besides other fields,

has a strong set up in IPM and biocontrol.

Recently Government of India has declared

the Biocontrol Lab as `Central Insecticide Lab’

for biopesticides. Similarly the Department also

holds big strength in mushroom research and

trainings.

In view of quality of teaching, research

and extension work being carried out by the

department, ICAR upgraded the department to

the status of CAS in Plant Pathology in the

year 1995 with the major mandate to train

scientific faculty from all over the country in

important and innovative areas of Plant

Pathology. So far 19 trainings have been

conducted and 395 scientists from 24 states

have participated.

The topic of the present training under

CAS is ‘Seed Health Management for better

productivity’. As you know, Increase in

agricultural production is the key to all-over

economic growth. Seed constitutes the main

propagule for plant growth and, at the same

time, one of the main vehicles for the

dissemination of plant pests. Seed-borne

pathogens, such as fungi, bacteria and viruses

are serious constraints to crop productivity. In

worst-case scenario, seed-borne diseases can

be disastrous and even life threatening. The

estimates reveal that on an average, 80 % of

the seed sown in the country is untreated as

against 100 % seed treatment being prcaticed

in the developed countries. In view of this, GOI

has launched 100% seed treatment campaign

all over the country. Besides, increasing crop

productivity seed health issues are exremely

important in international seed trade and

conservation and utilization of plant genetic

resources, which is vital for global food

security.

I will not go into the details about the

topic because it would be introduced to you

more appropriately by the Vice Chancellor.

However, I would like to mention that

seeds are priceless resources in ensuring

world food production, and seed health

management has become more meaningful

and essential than ever before. I would thus

like to extend my special gratitude to the

Faculty of Plant Pathology for their

endorsement of the topic for the present CAS

training.

Finally, I would like to thank our Vice-

Chancellor for allowing us to hold this CAS

training.

With these words I welcome you all and

assure a fruitful and comfortable stay to the

participants of this 20th training programme of

CAS in Plant Pathology.

Thank you very much!

iii

INAUGURAL ADDRESS by

Prof. A.P. Sharma

Vice-Chancellor


on

March 29, 2008

I consider it a great privilege and honour

to be called upon to Inaugurate the Training

Course “Seed Health Management For Better

Productivity” being organized by the Centre of

Advanced Studies (CAS) in Plant Pathology. I am

delighted to know that as many as 21 scientists

from the SAUs and Central Universities from all

over India are participating in the training course. I

extend my warm welcome to you all.

I hope all of you know that Pantnagar

University has a distinguished record of producing

outstanding Plant Pathologists. The

accomplishments of this Department have all

become self-evident as the faculty members and

their students have won nearly 40

national/international awards from different

recognized bodies like FAO, ICAR, Indian

Phytopathological Society, Society of Mycology

and Plant Pathology, Indian Society of Oilseeds

Research, Asian Agri-History Foundations and

many others. During the last two years, two

faculty members of the Department were

bestowed with “Uttaranchal Ratan Award” for their

outstanding contributions in the field of science.

Recently, another faculty member of the

department Dr. S.N. Vishwakarma, has been

bestowed with the ‘Education award’ of the

Ministry of Human Resources & Development,

Govt. of India for his book “Falon Ke Rog”. On

this occasion, I would further like to make a

mention of two great plant pathologists, Dr. Y.L.

Nene and Dr. R.S. Singh, who gave inspiring

leadership to the Department of Plant Pathology

soon after the establishment of the University on

November 17, 1960. You may well be aware that

discovery of Khaira diseases of rice due to zinc

deficiency and its control turned this Tarai into rice

bowl of the country. Thus the goal of

establishment of first Agriculture University in

India at Pantnagar was full-filled. It was this single

most important and simple factor in 1967 that

earned a name for the university as well as the

department by way of the coveted FAO award

conferred upon Dr. Nene. It is widely

acknowledged as one of the most important plant

pathological discovery not only in India but at the

global level that had maximum impact on farmers.

You may also be aware that Dr. R.S. Singh

worked out basic mechanisms for obtaining the

disease control of soil-borne plant diseases

through organic amendments, which is now

becoming a reality and way of organic farming.

His books are considered to be the milestones for

being handy text books both for under graduate

and post graduate students in Plant Pathology.

This department has to its credits considerable

number of research publications and many books

that have been published by some of the most

reputed national and international publishers from

the USA and Europe.

It is indeed a matter of great pleasure that

the Centre of Advanced Studies in Plant

Pathology is organizing this training under the

sponsorship of ICAR on a topic that is so relevant

to present day agriculture. Agriculture and food

markets, in the past 20 years, have dramatically

i

changed to become more integrated, globalized

and consumer driven. Incidentally, seed industries

provide the largest source of employment and

small businesses among the world’s poor, but

their roles vary greatly in different regional

contexts and stages of development.

Great grains in crop production have been

made in the Green Revolution in India and

elsewhere in a few Asian countries through the

use of seeds of high-yielding varieties with high

inputs of inorganic fertilizers, tillage and irrigation.

This has been experienced in North India more

particularly in the states of Punjab, Haryana,

Western Uttar Pradesh and in the adjoining Tarai

region of Uttarakhand. Unfortunately, the failure to

maintain yield gains under long-term cultivation

and fertilization and intensification of cropping

systems has been commonly attributed to decline

in the availability of quality seed.

Seed health issues have become

increasingly important in International Seed Trade

(IST). To provide means to answer scientifically the

problems encountered in the worldwide movement

of seed, an international movement has emerged

to standardize seed health tests and inspection

practices for International Seed Trade.

The economic significance of seed-borne

diseases increases with the changing global

scenario in light of the General Agreement on

Trade and Terrific (GATT). Sanitary and Phyto-

sanitary issues in WTO are pressurizing

developing countries to give special attention to

seed health testing. Appropriately, thus, seed

health has been recognized for statutory

regulation in seed quality tests and seed

treatment programmes. In this regard, national

and international cooperation has been sought for

effective seed health and crop protection. Trends

are emerging for need-based seed treatments,

and a shift from chemical treatments to bio-

pesticides. It is estimated that nearly 30%

diseases are of seed borne nature and can be

managed through disease-free seeds.

Seed health testing and management

needs to be understood in light of general evolution

of the seed sector. Estimation of losses attributed

to seed-borne inoculum, establishing predictive

relationships between seed-borne inoculum and

disease incidence, developing reliable, effective,

cheap and rapid detection methods, dialogue with

the private sector on development of test

procedures, and comparing data on advantages of

seed health are the current issues.

Regardless of the detection methodology,

the specificity, sensitivity, reliability, efficiency of

the assay, an understanding of pathogen

tolerance in a seed lot needs to be considered

before a technique is accepted as a clinical seed

health test. Acceptable seed health tests are tools

for disease risk-management and routinely used

in seed quality assessment. These considerations

help the countries in evolving policies and

methods for adoption of seed health testing as

part of plant protection to increase crop yields.

Thus, it becomes imperative that advancements

in Seed Health Management are closely

examined and adequately understood.

It is indeed a matter of great pleasure that

the Centre of Advanced Studies in Plant

Pathology is organizing this training in

collaboration with ICAR at this campus. It is

hoped that the scientists participating in this

course would effectively utilize the knowledge

earned not only in doing research and teaching

but also to find out ways and means of

transferring the technology to the farmer who is

the sole judge of our efforts.

I have thus pleasure in the declaring the

training course “Plant Disease Management on

Small Farms” open and I wish the training course,

discussions and deliberations a grand success.

“Jai Hind”

ii

(Seed Health Management for Better Productivity)

- 10 -

Department of Plant Pathology

J. Kumar Department of Plant Pathology, G.B.P.U.A.&T., Pantnagar-263145 (Uttarakhand)

Establishment of University – 1960

Department created and Accredited – 1961

M. Sc. (Ag) Programme – 1963

Ph. D. Programme – 1965

Ist course – Introductory Plant Pathology

Ist Instructor – Dr. Y. L. Nene

Ist HOD – Dr. Y. L. Nene

Courses:

5 UG courses

16 PG courses

Staff position:

14 Professor

01 Honorary Professor

01 Professor (Guest Faculty)

05 Associate Professor

02 Assistant Professor

13 Technical staff

10 Supporting staff

The G.B. Pant University of Agriculture & Technology (earlier known as U.P. Agriculture

University) was established in 1960. Department of Plant pathology was created and accredited by ICAR

in 1961. The postgraduate degree programme leading to M.Sc. (Ag.) Plant Pathology and Ph.D. Plant

Pathology were started in 1963 and 1965, respectively.

Faculty of Plant Pathology is highly qualified and includes 14 professors, 1 Honorary Professor, 1

Guest Faculty, 4 Associate Professors and 3 Assistant Professor with 13 technical staff and 10

supporting staffs. Besides, there are two senior professors as guest faculty in the department

Sl. No. Name of Faculty members Designation Area of specialization

1. Dr. Serge Savary Honorary Professor Epidemiology

2. Dr. S.C. Saxena Guest Faculty Maize diseases

3. Dr. J. Kumar Professor & Head Biotechnology

4. Dr. K.P. Singh Professor Wheat

5. Dr. R. P. Singh Professor Mushroom

6. Dr. A.P. Sinha Professor Rice disease & fungicides

7. Dr. H.S. Tripathi Professor Pulse diseases & virology


- 11 -

8. Dr. S.N. Vishwakarma Professor Vegetable & soybean

9. Dr. R.P. Awasthi Professor Oilseed crop disease

10. Dr. U.S. Singh Professor Biological control, IPM & Molecular Plant Pathology, Aromatic rices

11. Dr. K.S. Dubey Professor Soybean diseases

12. Dr. (Mrs.) K. Vishunavat Professor Seed Pathology

13. Dr. V.S. Pundhir Professor Epidemiology of crop disease

14. Dr. R.R. Dwivedi Professor Tea & aromatic plant diseases

15. Dr. Pradeep Kumar Professor Fruit diseases

16. Dr. R. K. Sahu Professor Sugarcane diseases

17. Dr. Vishwanath Assoc. Professor Oilseed Pathology

18. Dr. Yogendra Singh Assoc. Professor Sorghum diseases

19. Dr. K.P.S. Kushwaha Assoc. Professor Mushroom & pulse diseases

20. Dr. Akhilesh Singh Assoc. Professor Maize diseases

21. Dr. A.K. Tewari Assoc. Professor Oilseed crops diseases

22. Dr. K.K. Mishra Asstt. Professor Mushroom & pulse diseases

23. Dr. (Mrs.) Deepshikha Asstt. Professor Wheat diseases

TEACHING

The department of plant pathology has made immense contribution in the area of teaching,

research and extension. A well-knit UG and PG programme with updated and modern syllabi is

already in operation in the department. The department offers 6 courses for undergraduate

students. There are 20 postgraduate courses leading to M.Sc. (Ag.) and Ph.D. degrees in Plant

Pathology. Since the inception of the department 290 M.Sc. (Ag.) and 155 Ph.D. students have

been awarded degrees.

Under graduate courses:

1961’s Introductory Plant Pathology

Present

APP-312 Introductory Plant Pathology (2) APA/APP/APE-319 Organic Farming (2)

APP-314 Crop disease & their management (2) APP/APE-321 Integrated Pest Management (2)

APP-321 Mushroom cultivation (1)

Post graduate courses:

Core courses

APP-500 Principles of Plant Pathology (2) APP-520 Diagnosis of Plant Diseases (2)

APP-505 Phytopathological Techniques (2) APP-600 Seminar (1)

APP-515 Phytobacteriology (2) APP-690 Thesis Research (15)

APP-530 Phytovirology (2)


- 12 -

Basic Supporting Courses

BBB-625 Mycology I (3) BBB-626 Mycology II (3);

BPS-661 Experimental Statistics (4) BPM-502 Computer (2)

Optional courses – 6 Cr. Hr.

APP-610 Principle of Plant Disease Control (3)

APP-615 Seed Pathology (2)

APP-640 Fungicides (3)

APP-604 Diseases Resistance in Plants (2)

APP-612 Introduction to Edible Fungi (3)

APP-624 Cultural and Chemical Control of Plant Parasitic Nematodes (2)

APP-630 Phytonematology (2)

APP-602 Diseases of Ornamental and Medicinal Plants (2)

Deficiency Courses

For B. Sc. (Ag):

APP-410 Disease of Field Crops (3)

APP-430 Diseases of Horticultural Crops (3)

For ZBC:

APP-401 Introductory Plant Pathology (3)

APA-401 Elements of Crop Production (3)

APH-401 Introduction to Horticulture (3)

APP-410 Disease of Field Crops (3)

APP-430 Diseases of Horticultural Crops (3)

Ph.D. Courses:

APP-600 Seminar (1- 2)

APP-604 Disease Resistance in Plants (2)

APP-640 Fungicides (3)

APP-700 Epidemiology of Plant Diseases (2)

APP-710 Biochemistry of Plant Infection (2)

APP-720 Ecology of Soil Borne Plant Pathogens (3)

APP-790 Thesis Research (30)

Minor: 10 Cr.hr.

Books Published

The department has unique distinction of producing 33 books published by not only Indian

but also reputed international publishers like Elsevier Science (UK), Gordon and Beach (UK),

Prentice Hall (USA), CRC Press (USA), Science Publisher (USA), Lewis Publishers (USA) etc. It

has also produced 13 technical bulletins. A number of text books in Hindi for U.G. students have

been published. The faculty members have written/prepared several laboratory manuals,


- 13 -

reference books, working sheets on diseases, bulletins, extension pamphlets, etc. for the benefit of

U.G. and P.G. students of plant pathology as well as for the farmers.

(A) Hindi – (10) (B) English– (33)

Plant Disease 8th Edition by Dr. R.S. Singh

An Introduction to Principles of Plant Pathology 4th Edition by Dr. R.S. Singh

Plant Pathogens: The Fungi by Dr. R.S. Singh

Plant Pathogens: The Viruses & Viroids by Dr. R.S. Singh

Plant Pathogens: The Prokaryotes by Dr. R.S. Singh

Integrated Disease Management by Dr. R.S. Singh

Diseases of Fruit Crops by Dr. R.S. Singh

Fungicides in Plant Disease Control by Drs. P.N. Thapliyal and Y.L. Nene

Diseases of Annual Edible Oilseed Crops Vol.-I by Dr. S.J. Kolte

Diseases of Annual Edible Oilseed Crops Vol.-II by Dr. S.J. Kolte

Diseases of Annual Edible Oilseed Crops Vol.-III by Dr. S.J. Kolte

Diseases of Linseed & Fibre Flex by Dr. S.J. Kolte

Castor Diseases & Crop Improvement by Dr. S.J. Kolte

Plant Diseases of International Importance Vol.I: Diseases of Cereals & Pulses by

Drs. U.S. Singh, A. N. Mukhopadhyay, J. Kumar, and H.S. Chaube

Plant Diseases of International Importance Vol.II: Diseases of Vegetables & Oil Seed

Crops by Drs. H.S. Chaube, U.S. Singh, A. N. Mukhopadhyay & J. Kumar

Plant Diseases of International Importance Vol.III: Diseases of Fruit Crops by Drs. J.

Kumar, H.S. Chaube, U. S. Singh & A. N. Mukhopadhyay

Plant Diseases of International Importance Vol.IV: Diseases of Sugar, Forest &

Plantation Crops Drs A. N. Mukhopadhyay, J. Kumar, H.S. Chaube & U.S. Singh

Pathogenesis & Host Specificity in Plant Diseases Vol.I: Prokaryotes by Drs. U. S.

Singh, Dr. Keisuke Kohmoto and R. P. Singh

Pathogenesis & Host Specificity in Plant Diseases Vol. II: Eukaryotes by Drs. Keisuke

Kohmoto, U.S. Singh and R. P. Singh

Pathogenesis & Host Specificity in Plant Diseases Vol. III: Viruses & Viroids by R. P.

Singh, U.S. Singh and Keisuke Kohmoto.

Aromatic Rices by Drs. R.K. Singh, U.S. Singh and G. S. Khush

A Treatise on the Scented Rices of India by Drs. R.K. Singh and U.S. Singh

Scented Rices of Uttar Pradesh & Uttaranchal by Drs. R. K. Singh and U.S. Singh

Plant Disease Management : Principles & practices by Drs. H.S. Chaube and U.S.

Singh

Molecular Methods in Plant Pathology by Drs. R. P. Singh and U.S. Singh

Soil Fungicides Vol.-I by Drs. A.P. Sinha and Kishan Singh

Soil Fungicides Vol.-II by Drs. A.P. Sinha and Kishan Singh


- 14 -

Experimental & Conceptual Plant Pathology Vol.I: Techniques by Dr. R.S. Singh, U. S.

Singh, W.M. Hess &D.J. Weber

Experimental & Conceptual Plant Pathology Vol. II: Pathogenesis and Host

Specificity by Dr. R.S. Singh, U. S. Singh, W.M. Hess & D.J. Weber

Experimental & Conceptual Plant Pathology Vol.III: Defense by Dr. R.S. Singh, U. S.

Singh, W.M. Hess &D.J. Weber

Seed Pathology, 2 volumes by Dr. V.K. Agarwal

Phytopathological Techniques by Dr. K. Vishunavat and S.J. Kolte

Crop Diseases & Their Management by H.S. Chaube & V.S. Pundhir

Laboratory Manuals published:

Introductory Plant Path (UG) : H. S. Chaube, V. S. Pundhir, S. N. Vishwakarma

Crop Diseases & Their Management : A. N. Tewari

Diagnosis of Plant Diseases : A. N. Tewari

Identification of Plant Disease

& their control

: A. N. Tewari

Phytovirology : Y.P.S. Rathi, H. S. Tripathi & P. Kumar

Introductory Plant Pathology (UG) : YPS Rathi, P. Kumar & H. S. Tripathi

RESEARCH

Research work in the department began since the inception of the University. With the

addition of new programme and staff strength, the research activities got diversified

encompassing, Ecology of soil borne plant pathogens, Epidemiology and Forecasting, Biological

control and IPM, Molecular Biology and Population Biology, Seed Pathology, Fungicides,

Nematology, Phytovirology, Phytobacteriology and Biology & Technology of Mushroom

Production. The department has several research projects funded by national and international

funding agencies. The department is guiding the research work at the regional station such as

Bharsar, Kashipur, Lohaghat, Majhera and Ranichauri on pathological aspects. The scientists of

the department have won many national and international awards.

The department is actively engaged in the research work on both fundamental and applied

aspects in frontier areas of plant pathology. The plant protection technology developed by the

department is being effectively communicated to the farming community of state of Uttaranchal.

The department has to cater the needs of not only farmers of the plain but also of hills located at

different altitudes. In hills crops, diseases and cropping practices vary a lot depending on altitudes

and they are quite different from plain. This offers a big challenge to the Centre of Advanced

Studies in Plant Pathology.


- 15 -

Significant Contribution

Cause and control of Khaira disease of rice

Development of selective media for isolation and enumeration of Pythium and Fusarium

Mechanism of biological control in soil amended with organic matters

Biology and characterization of legume viruses

Ecology of soil – borne pathogens (Fusarium, Pythium, Rhizoctonia solani, Sclerotium rofsii)

Mechanism of absorption, translocation and distribution of fungicides in plants

Methods for quantitative estimation of fungicides like metalaxyl, organotin compounds, carbendazim

etc.

Hormonal action of fungicides

Phenolics in Plant disease resistance

Biological control with introduced antagonists

Etiology & management of mango malformation

Etiology and management of shisham wilt.

Epidemiology and Genetics of Karnal bunt fungus

Population biology of rice blast fungus, Magnaporthe grisea

Mechanism of intra-field variability in Rhizoctonia solani

Soil solarization

Mushrooms – Development of strains, and production technologies

Role of Ps. fluorescens in sporophores development of A. bisporus

Compost formulation with Sugarcane baggase + Wheat Straw, 2:1 developed to reduce cost of

cultivation of Agaricus bisporus.

Developed chemical treatment (Formalin 15ml + Bavistin 0.5g/10kg compost) of long method

compost to avoid the moulds in cultivation of A. bisporus.

Recommended supplementation of substrate with 2% mixture of Neem cake + Wheat straw + Rice

bran + Soybean meal for Pleurotus spp. cultivation.

Standardized cultivation of Auricularia polytricha using sterilized wheat straw supplemented with

wheat bran (5%).

Standardized cultivation of Lentinula edodes with substrate

popular sawdust.

Systemic induced resistance in brassicae.

Use of siderophore producing Pseudomonads for early fruiting

and enhanced yield of Agaricus bisporus.

Use of Pseudomonas fluorescens for control of mushroom

diseases caused by Verticillium, Sepedonium, Trichoderma and Fusarium.

Pleurotus sajor-caju and P. florida recommended for commercial cultivation using soybean straw /

Paddy straw / Wheat straw / Mustard straw.

Standardized cultivation technology for Hypsizygus almarius using wheat straw supplemented with

wheat bran.

Lentinula edodes


- 16 -

Standardized cultivation of Calocybe indica using wheat

straw as a substrate with casing of FYM + Spent Compost

+ Sand (2:1:1).

A relay cropping schedule developed for Tarai region of

Uttaranchal: two crops Agaricus bisporus (Sept. - March), four

crops Pleurotus spp. (Sept.- Nov. and Feb.,- April) and three

crops of Calocybe indica (March-October).

Developed two strains of Agaricus bisporus, Pant 31 and Pant 52, now included in multilocational

testing under coordinated trials.

Development and commercialization of seven hybrids of oyster mushroom.

Associated with multilocational testing and release of the strains NCS-100, NCS-102, NCH-102 of

A. bisporus.

120 mushroom species from different locations in Uttaranchal

have been collected and preserved in the museum of the

centre.

Of the collected mushrooms five Auricularia, four species of

Pleurotus and two species of Ganoderma have been brought

under cultivation.

Developed / standardized technology for production of traditional

value added mushroom products viz. ‘Sev’, ‘Warian’, ‘Papad’ and ‘Mathri’.

Isolated a high value cater pillar mushroom

Cordyceps sinensis from high altitudes of

Uttaranchal and analysed for antioxidative

properties.

MAJOR ACHIEVEMENTS

Twenty seven wheat lines, combining better agronomic characteristics and resistance to diseases

including Karnal bunt have been identified (Shanghi-4, BW 1052, HUW 318, Lira/Hyan’S’ VUI’S’,

CUMPAS 88, BOBWHITE, SPRW 15/BB/Sn 64/KLRE/3/CHA/4/GB(K)/16/VEE/ GOV/AZ/MU, NI9947,

Raj 3666, UP 1170, HS 265, HD 2590, HS317, PH 130, PH 131, PH 147, PH 148, PH 168, HW 2004,

GW 188, MACS 2496, CPAN 3004, K8804, K8806, ISWYN-29 (Veery”S”) and Annapurna).

Foliar blight of wheat has now been assumed as a problem in

Tarai areas of U.P and foothills of Uttaranchal. Bipolaris

sorokiniana - Dreschlera sorokiniana, was found associated

with the disease in this area. Karnal bunt of wheat caused by

Tilletia indica Mitra, is widely distributed in various Western

and Eastern districts of U.P while the North hills and Southern

dry areas are free from the disease.

Ganoderma lucidum

Cordyceps sinensis

Calocybe indica


- 17 -

Multiple disease control in wheat has been obtained by seed treatment with Raxil 2DS @

1.5g/Kg seed + one foliar spray fungicide Folicur 250 EW (Tebuconazole) @ 500ml/ha, which

controls loose smut, brown rust, yellow rust, powdery mildew and leaf blight disease very

effectively.

The mixture of HD 2329 + WH 542 + UP 2338 produced highest yield recording 11.67 per cent

higher as compared to average yield of their components.

Among new fungicides Raxil 2DS (Tebuconazole) @ 1.0, 1.5, 2.0 and 2.5g/kg seed, Flutriafol

and Dividend @ 2.5g/Kg seed were found highly effective in controlling the disease. Raxil 2DS

@ 1.5g/Kg seed as slurry treatment gave complete control of loose smut.

New techniques for embryo count and seedling count for loose smut, modified partial vacuum

inoculation method of loose smut, creation of artificial epiphytotics of Karnal bunt, NaOH seed

soaked method for Karnal bunt detection and detached leaf technique for screening against

leaf blight using pathogen toxin developed.

The major emphasis has been on the screening of maize germplasms to various diseases with

special reference to brown stripe downy mildew, banded leaf and sheath blight and Erwinia

stalk rot. A sick-plot has been developed to ensure natural source of inoculum. Efficient

techniques for mass multiplication of inoculum and screening of germplasms have been

developed to create epiphytotic conditions. The selected genotypes have been utilized for

evolving agronomically adaptable varieties. Several promising hybrids and composites have

developed and released following interdisciplinary approach.

Studies on estimation of yield losses, epidemiological parameters on various economically

important diseases of maize have been worked out to evolve suitable control measures and

have been recommended to farmers in the region.

Based on the survey and surveillance studies the information on the occurrence of various

diseases in UP and Uttaranchal, a disease map has been prepared and monitored to finalize the

out breaks of one or more diseases in a given area based on weather parameters. It will help the

growers to be prepared to save the crop from recommended plant protection measures.

An repository of >600 isolates of biocontrol agents developed at Pantnagar & Ranichauri.

These isolates are suited for different crops & agro-ecological conditions.

Standard methods developed for testing hyphal and sclerotial colonization.

Isolate of T. virens capable of colonizing sclerotia of Rhizoctonia, Sclerotium and Sclerotinia

isolated for the first time. It may have great potential.

16 new technologies related with mass multiplication and formulation of microbial bio-agents

developed and are in the process of being patented.

Several genotypes including SPV 462, SPV 475, SPV 1685, SPH 1375, SPH 1420, CSV 13,

CSV 15, CSH 14, CSH 16, CSH 18, G-01-03, G-09-03, GMRP 91, RS 629, UTFS 45, UTMC

523 and AKR 150 have been identified with high level of resistance to anthracnose and zonate

leaf spot diseases.


- 18 -

Biocontrol agents T. harzianum and P. fluorescens have been found effective in increasing the

growth of plants and reducing the severity of zonate leaf spot. G. virens and T. viride have

been found most effective against anthracnose pathogen.

The cause of Khaira as zinc deficiency was established for the first time and zinc sulphate

+slacked lime application schedule was developed for the control of the disease

Inoculation technique was developed to create “Kresek” phase in rice seedlings. Pre-planting root

exposure technique in a suspension of 108cells/ml for 24 hrs gave the maximum “Kresek”. Root

inoculation, in general was found better for development of wilt symptoms than shoot inoculation.

A simple technique has been developed to detect the pathogen in and/or on seeds. The

presence of viable pathogen has been demonstrated from infected seeds stored at room

temperature up to 11 months after harvest.

The disease is sporadic in occurrence often becomes serious in nature. Chemical control trials

showed that the disease can effectively be controlled by giving 2-3 foliar sprays of

streptocycline @ 15 g/ha.

A number of new fungicides along with recommended ones and botanicals were tested against

sheath blight. Foliar sprays with Anvil, Contaf, Opus, Swing and RIL F004 @ 2 ml/l and Tilt @

1 ml/l were found highly effective in controlling sheath blight. Foliar sprays with Neem gold @

20 ml /lit. or Neem azal @ 3ml/lit. was found significantly effective in reducing sheath blight

and increasing grain yield.

Foliar sprays with talc based formulations of the bioagents (Trichoderma harzianum, or

Pseudomonas fluorescence, rice leaf isolates) were found effective in reducing sheath blight

and increasing grain yield. Foliar sprays with the bioagents (T.harzianum) or P. fluorescence)

given 7 days before inoculation with R. solani was highly effective against the disease.

Seed or soil treatment with T. harzianum or P. fluorescence @ 2, 4 or 8 g/kg enhanced root

and shoot growth and fresh and dry weight of rice seedlings.

Seed treatment with fungorene followed by one spray of carbendazim (@ 0.05% at tillering at

diseases appearance) and two sprays of Hinosan @ 0.1% at panicle initiation and 50%

flowering was most effective and economical treatment in reducing the disease intensity and

increasing the yield.

For the first time, true sclerotia were observed in Kumaon and Garhwal regions at an altitude of

900 m above. True sclerotia have a dormancy period of approximately six months. Exposure of

sclerotia to near ultraviolet radiation for an hour breaks the dormancy and increased

germination.

Trichoderma may reduce population of earthworm in

vermicomposting during early days

An repository of >600 isolates of biocontrol agents developed at

Pantnagar & Ranichauri. These isolates are suited for different

crops & agro-ecological conditions.


- 19 -

Isolates of T. virens capable of colonizing sclerotia of Rhizoctonia, Sclerotium and Sclerotinia

isolated for the first time. It may have great potential.

Standard methods developed for testing hyphal and sclerotial colonization.

16 new technologies related with mass multiplication and formulation of microbial bioagents

developed and are in the process of being patented.

Effect of different physical factors and extracts on the germination of true sclerotia was studied.

Maximum germination was observed at 250 C and at pH 6.0, in fluorescent light. Among the

substratum, maximum germination occurred on moist sand. Soil extract was more favourable

than other extracts. The number of stipes and mature head formation was directly correlated

with the size and weight of the sclerotia.

The viability of the 3 propagules namely; conidia, pseudo and true sclerotia stored under

different conditions showed that conidia remain viable from 2-3 months, pseudo- sclerotia from

4-6 months and true sclerotia up to 11 months at room temperature and under field conditions.

True sclerotia buried at different depth (2.5 to 10 cm) in soil germinated well, but scleroita

buried at 15 cm depth did not germinate and rotted.

Discoloured grains of various types were grouped according to their symptoms. The fungi

responsible for each type of symptoms were identified. Ash grey discolouration of glumes

separated by dark brown band was caused by Alternaria alternata and Nigrospora oryzae.

Spots with dark brown margin and ash grey centre by Curvularia lunata and Alternaria

alternata, light yellow to light brown spots by C. pallescens, Fusarium equiseti and N. oryzae,

Brown to black dot by Phyllosticta oryzae Dark brown to black spot and specks by Drechslera

victoriae, D. rostratum and D. oryzae, light to dark brown glumes by Sarocladium oryzae and

D. oryzae, and light to dark brown spots by D. Australiense.

Rice varieties Manhar, Narendra 80, Saket 7, Ajaya, Bansmati, 385 showed higher incidence

(34.1 to 41.8%) whereas Sarju 52, UPR 1561-6-3, Pusa 44, Jaya, Pant Dhan 10 and improved

Sharbati exhibited lower (18.4-22.3%) incidence of seed discolouration. Bipolaris oyzae

caused highest seed discolouration which is followed by Fusarium moniliforme, curvularia

lunata and Fusarium graminium in all the test varieties.

On the basis of the symptoms pattern and transmissibility of the pathogen through grafting and

eriophyied mite (Aceria cajani), presence of foreign ribonucleic protein and nuclear inclusion

like bodies in the phloem cell indicated the viral (RNA virus) nature of the pathogen of sterility

mosaic of pigeon pea. The vector mite of the pathogen was found on lower surface of leaves

of Canavis sativus and Oxalis circulata weeds in this area. Mild mosaic, ring spot and severe

mosaic symptoms were observed in different as well as same cultivar. This observation reveals

the presence of variation in the pathogen.

Germplasm lines/ cultivars screened viz; ICP 14290, ICP 92059,ICP 8093, KPBR 80-2-2, PL

366, ICPL 371, Bahar, NP (WR) 15.were found resistan against Phytophthora stem blight.


- 20 -

Some resistant donors for mungbean yellow mosaic virus have been identified i.e. UPU-

1,UPU-2,UPU-3, UG-370, PDU-104, NDU-88-8, UG-737, and UG-774. The varieties thus

evolved include PU-19, PU- 30, and PU-35., Manikya, resistant lines/cultivars identified: ML-

62, ML-65, Pant M-4, Pant M-5, ML-131, NDM 88-14, ML-682, PDM-27, ML- 15, ML-803, ML-

682 and 11/ 395 and for Urdbean leaf crinkle virus, SHU 9504, -9513,-9515, -9516, -9520, -

9522, -9528, KU 96-1, UG 737 and TPU-4.

Seed treatment with carbendazim (0.1%) followed by two prophylactic sprays of carbendazim

(0, 05%) or Dithane M-45 @ 0.25% was found most effective in reducing disease severity of

anthracnose disease. In early sown crop high disease severity was observed while in late

sown crop low disease severity was recorded. Inter cropping with cereals or pulses have no

effect on anthracnose severity.

Propiconazol 0.1%, carbendazim 0.1%, hexaconazol 0.1%, mancozeb 0.25% sprayed plots

have low disease severity and high grain yield against Cercospora leaf spot.

Studies on integrated management of wilt/root rot/collar rot showed that Seed treatment with

fungicide alone or in combination with other fungicides/ bio agents were found effective.

Among the fungicides seed treatment with Bavistin + Thiram (1:2), vitavax + Thiram (1:2),

vitavax, Bavistin, Bayleton, Bio agent Gliocladium virens + Vitavax and Pseudomonas

fluorescence) decreased the seedling mortality, improved germ inability, plant stand and yield.

Ten thousand germplasm lines/ breeding populations F2, F3,

F4 and F5 generations were screened. Many germplasm/

accessions were found resistant/ tolerant to Botrytis gray

mould viz; ICC 1069, ICC 10302, ICCL 87322, ICC 1599, -

15980, - 8529, ICCV 88510, E100Y (M) BG 256, BG261,

H86-73, IGCP 6 and GNG 146.

Lentil entries evaluated under sick plot for wilt/root rot/ collar

rot diseases. The following lines were found promising viz;

LL 383, PL 81-17, LH 54-8, DPL-58, DPL 14, Jawahar Massor- 3, DPL 112, IPL-114, L 4147

and Pant L 639.

The promising germplasm lines/ cultivars are as follows: DPL 62, PL-406, L 4076, TL 717, E

153, IPL 101, IPL 105, PL- 639, LH 84-8, and Precoz .

The field pea lines were found promising JP 141, Pant P-5, KFPD 24 (swati), HUDP 15, KFPD-

2, HFP-4, P1361, EC-1, P-632, P 108-1, KPMR 444, KF 9412, DPR 48, T-10, KPMRD348,

DDR13, IM9102, KFP 141 and KPMR 467 against powdery mildew and JP 141, Pant P-5, P

10, FP 141, KDMRD 384, HUDP-9, HUP-2 and T-10 were found promising against rust

disease.

Mid-September planting or early October planting of rapeseed-mustard has been found to

escape from Alternaria blight (Alternaria brassicae) downy mildew (Peronospora parasitica)

and white rust (Albugo candida) diseases as against mid and late October planting. In general


- 21 -

high occurrence of the floral infection (staghead phase) of white rust and downy mildew during

flowering period has been found to be associated with reduced period, i.e. 2-6 hours, of bright

sunshine/day concomitant with the mean maximum temperature of 21-250C, the mean

minimum temperature of 6-100C and higher total rainfall up to 166 mm. Bright sunshine hours

/day has a significant negative correlation whereas total rainfall has a significant positive

correlation with staghead development.

All the three important foliar diseases of rapeseed-mustard could be effectively controlled by

following integrated package of balanced N100 P40K40 application, early October sowing and

treating the seed with Apron 35 SD @ 6g kg-1 seed followed by spray of mixture of metalaxyl +

mancozeb (i.e Ridomil MZ 72 WP @ 0.25%) at flowering stage and by spray of mancozeb or

iprodione @ 0.2% at pod formation stage. In situations where Sclerotinia stem rot and / or

powdery mildew appeared to be important in a particular crop season, a spray of mixture of

carbendazim (0.05%) + mancozeb (0.2%) was found to give excellent cost effective control of

the diseases with significant increase in seed yield of the crop.

Among the botanicals, leaf extracts of Eucalyptus globosus (5%) and Azadirchta indica (5%)

have been proved to exhibit greater antifungal activity against A. brassicae and Albugo

candida and showed significant reduction in the severity of Alternaria blight and white rust

diseases which was rated to be at par with mancozeb fungicide spray.

Some abiotic chemical nutrient salts such as calcium sulphate (1%), zinc sulphate(0.1%) and

borax (0.5%) and biocontrol agents such as Trichoderma harzianum and non-aggressive D

pathotype of A.brassicae have been shown to induce systemic host resistance in mustard

against aggressive “A” pathotype of A. brassicae and virulent race(s) of A. candida.

The staghead phase in B. juncea has been investigated to be due to A. candida and not due P.

parasitica. Tissues at the staghead phase become more susceptible to P. parasitica than

normal tissues of the same plant.

B. juncea genotypes (EC 399296, EC 399299, EC 399301, EC 399313, PAB-9535, Divya

Selection-2 and PAB 9511), B. napus genotypes (EC 338997, BNS-4) and B. carinata (PBC-

9221) have been shown to possess resistance to white rust coupled with high degree of

tolerance to Alternaria blight. Reduced sporulation is identified to be the major component for

slow blighting.

B. juncea (RESJ 836), B. rapa (RESR 219) and B. napus (EC 339000) have been selected for

resistance to downy mildew and for high yield performance. Total 52 genotypes of mustard

representing at least 12 differential resistance sources, 23 lines of yellow sarson representing

6 differential resistance sources and 54 lines of B. napus representing 3 differential resistance

sources to downy mildew have been identified.

A new short duration (95-100 days) short statured (85- 96 cm) plant type of mustard strain

‘DIVYA’ possessing high degree of tolerance to Alternaria blight suitable for intercropping with

autumn sown sugarcane and potato yielding with an average of 15-22 q ha-1 has been


- 22 -

developed. This ‘Mustard DIVYA’ plant type is now recommended as a source for breeding

more and more improved varieties of mustard as it has been proved to have good general

combining ability for short stature characteristics.

Seed treatment with mancozeb @ 0.2% + thiram @ 0.2% has been found to control seed,

seedling and root rot diseases of groundnut. However seed treatment with thiram @ 0.2% +

vitavax @ 0.2% has been found to control collar rot (Sclerotium rolfsii) of groundnut. Two

sprays of carbendazim @ 0.05% have been found to give excellent control of early and late

leaf spot (tikka disease) of groundnut.

Mid September planting of sunflower was found to escape the occurrence of major diseases

like Sclerotinia wilt and rot, Sclerotium wilt, charcoal rot and toxemia. Severity of Alternaria

blight was found to be negligible and did not cause any reduction in yield. The crop could be

harvested by 15th December. The yield obtained was 16 q/ha.

The average percent loss has been noted in the range of 50.6 to 80.7 percent due to Alternaria

blight disease under Kharif conditions. However, the percent loss in oil has been shown in the

range of 21.6 to 32.3. To control the disease, total 4 sprays of mancozeb @ 0.3% at 10 day

interval have been found effective.

A repository of about 5000 rice blast isolates was made from 30 locations in Indian Himalayas at

Hill Campus, Ranichauri. Blast pathogen population from the region was analyzed using molecular

markers and phenotypic assays. Most locations sampled and analyzed had distinct populations

with some containing one or a few lineages and others were very diverse. Within an

agroecological region migration appeared to be high. The structure of some populations could be

affected to some extent by sexual recombination.

Magnaporthe grisea isolates derived from Eleusine coracana, Setaria italica and Echinochloa

frumentaceum collected from a disease screening nursery were cross compatible. The

chromosome number of each isolate was found to be six or seven. Similarity of karyotypes was

found among isolates with in a lineage though between lineages some variability was noticed. A

remarkable similarity between karyotypes of Eleusine coracana and Setaria italica was observed. All

of these isolates were fertile and mated with each other to produce productive perithecia. The

existing data however showed no evidence of genetic exchange among host-limited M. grisea

populations in Indian Himalayas.

No strong relationship appeared between the number of virulences in a pathotyope and its frequency

of detection. The frequency of virulent phenotype to a cultivar and susceptibility of that cultivar in the

field did not correspond. The number of virulences per isolate was in general less than the number

of virulences per pathotype, which indicated predominance of isolates from pathotypes with fewer

virulences. There was a tendency for the pathotypes to have fewer virulences. The frequency of

virulence among rare pathotypes was higher than common pathotypes against all the differential

NILs, including two-gene pyramids. These rare pathotypes could be the potential source of

resistance breakdown of the novel resistance genes.


- 23 -

Blast resistant gene Pi-2(t) appeared to have the broadest and Pi-1(t) the narrowest resistant

spectra. Compatibility to Pi-2 (t) gene did not appear to limit compatibilities with other resistant

genes. Loss of avirulence to all the five major gene tested may carry a serious fitness penalty.

Major gene Pi-2 and gene combination Pi-1,2 showed least compatibilities and hold promise

in managing blast in the region. In the overall Himalayan population, gene combinations in

general were effective at most locations. Combination of Pi-1+2 genes was effective at most

locations until the year tested. However, three gene pyramid [Pi-1(t) + Pi-2(t)+Pi-4(t)] resisted

infection at all locations.

It was inferred that the pathotype composition of the blast pathogen composition in the Indian

Himalayas was very complex and diversifying the resistance genes in various rice breeding

programmes should prove to be a useful strategy for disease management.

A common minimum programme under bio-intensive IPM in vegetables in Uttaranchal hills was

designed that is extended to over 2000 farmers from 20 villages in district Tehri Garhwal.

Epidemiological considerations in the apple scab disease management led to the development

of disease prediction models. Relation of degree-day accumulations to maturation of

ascospores, and potential ascospore dose (PAD) were found to be useful for predicting the

total amount of inoculum in an orchard thereby effectively improving apple scab management.

Out of 71 genotypes tested against red rot caused by Colletotrichum falcatum, four genotypes

viz; Co Pant 92226, Co Pant 96216, Co Pant 97222 and CoJ 83 were found resistant and

another 24 exhibited fairly good tolerance.

Seed treatment with Thiram + Carbendazim (2:1) @ 3g/kg seed or Vitavax 0.2% controlled the

seed and seedling rots and improved the seedling emergence without any adverse effect on

the nodulation and invariably yield were increased. Seed treatment with Trichoderma

harizianum, T. viride or Pseudomonas fluorescens @ 10g/kg controlled seed and seedling rots

and increased plant emergence.

Purple seed stain disease can be effectively controlled by seed treatment with thiram +

carbendazim (2:1) @ 3 g/kg seed followed by two sprays of benomyl or Carbendazim @ 0.5

kg/ha.

Rhizoctonia aerial blight can be effectively controlled by two sprays of carbendazim @ 0.5

kg/ha. Seed treatment with T. harzianum or Pseudomonas fluorescens 10g/kg seed + soil

treatment with pant Bioagent-3 mixed with FYM @50q/ha followed by two sprays of T.

harzianum @ 0.25% reduced the disease severity of RAB.

Pod blight and foliar diseases caused by Colletrotichum dematium var truncatum could be

effectively controlled by the use of carbednazim 0.05%, Mancozeb 0.25%, Copperoxychloride

0.3%, Thiophanate methyl 0.05%, Chlorothalonil 0.25%, Hexaconazole 0.1% and


- 24 -

Propiconazole 0.1%. First spray should be given as soon as disease appear and second spray

after 15 days of first spray.

Rust disease could be effectively controlled with three sprays of Benomyl 0.05%, Mancozeb

0.25% or Zineb 0.25%, at 50, 60 and 70 days after sowing. Varieties Ankur, PK-7139, PK-

7394, PK-7121, PK-7391 were resistant.

Charcoal rot disease can be effectively controlled by seed treatment with Trichoderma

harzianum @ 0.2% + vitavax @ 0.1%.

Pre-mature drying problem Soybean can be minimized by seed treatment with carbendazim +

Thiram (2:1) @ 3g/kg seed followed by two sprays with carbendazim, mancozeb and

Aureofungin. Varieties PSS-1, PS-1042, PK-1162, PK-1242 and PK-1250 were found to be

superior for premature drying problem.

Integrated disease management (IDM) modules based on combined use of cultural practices,

fungicides for fungal disease, insecticide for virus disease and host resistance were evaluated

against RAB and Soybean yellow Mosaic virus diseases.

Bacterial pustules can be successfully controlled by two sprays at 45 and 55 days after

planting with a mixture of Blitox-50 (1.5 kg/ha) + Agrimycin-100 (150g/ha) or streptocycline

(150 g/ha) + copper sulphate (1kg/ha).

Soybean yellow Mosaic can be very effectively controlled by four sprays with oxymethyl

demoton @ 1l/1000 lit/ha at 20, 30, 40 and 50 days after planting. Soil application with Phorate

10G @ 10 kg/ha and Furadan 3G @ 17.5 kg/ha controlled the disease. Varieties PK-1284,

1251, 1259, 1043, 1225, 1303, 1314, 1343, 1347, PS-1042 PS-564, 1364 were identified as

resistant to Soybean yellow Mosaic virus.

EXTENSION

The scientists also participate in the farmers contact programme as well as practical

trainings at different levels including those of IAS and PCS officers, Extension workers, Agricultural

officers, Farmers, Defense Personnels etc. The Scientists of the department also actively

participate in the trainings organized under the T&V programme for the benefit of farmers/State

level Agricultural Officers. Two Professors (Extension Pathology) and crop disease specialists are

deputed to “Help Line Service” started recently by the University under Agriculture Technology

Information Centre (ATIC). The telephone number of help line services is 05944-234810 and 1551.

Technology developed by the centre is regularly communicated to the farmers of the 13 districts of

Uttaranchal State through the extension staff (Plant Protection) of both university and state

agriculture and horticulture departments posted in all districts of the state. The radio talks and TV

programme are delivered. Popular articles and disease circulars are published regularly for the

benefit of the farmers.


- 25 -

UP-GRADATION TO CENTRE OF ADVANCED STUDIES

In view of the outstanding quality of teaching, research and extension work being carried out by

the department, ICAR vide letter No. 1-2/93 (CAS)UNDP dated Feb.02, 1995 upgraded the department

to the status of the centre of advanced studies in plant pathology. Major mandate of the CAS was to train

scientific faculty from all over the country in important and innovative areas of plant pathology. So far

under CAS, 16 trainings have been conducted and 336 scientists from all over the country have been

trained in different areas. Centre of Advanced Studies in Plant Pathology at Pantnagar was awarded a

certificate of Appreciation in commemoration of Golden Jubilee year of independence (1998) for

organizing the programmes for human resource development and developing excellent instructional

material by the education division, ICAR on August 14, 1998. The progress report CAS in Plant

Pathology during X plan is as follows:

Trainings Held

1. Recent advances in biology, epidemiology and management of diseases of major kharif

crops (Sept. 19- Oct. 12, 1996)

2. Recent advances in biology, epidemiology and management of diseases of major rabi crops

(Feb. 25 –March 18, 1997)

3. Ecology and ecofriendly management of soil-borne plant pathogens (Jan 12 – Feb. 02, 1998)

4. Advanced techniques in plant pathology (Oct. 12 – Nov. 02, 1998)

5. Recent advances in detection and management of seed-borne pathogens (March 10-30,

1999)

6. Recent advances etiology and management of root-rot and wilt complexes (Nov. 26 – Dec.

16, 1998)

7. Integrated pest management with particular reference to plant diseases: concept, potential

and application (Nov. 23 –Dec. 13, 2000)

8. Recent advances in research on major diseases of horticultural crops (March 01-30, 2001)

9. Recent advances in plant protection technology for sustainable agriculture (Nov. 19 –Dec.

09, 2001)


- 26 -

10. Plant diseases diagnosis: past, present and future (Feb. 13, - March 05, 2002)

11. Chemicals in plant protection: past, present and future (Jan. 28 – Feb. 17, 2003)

12. Eco-friendly management of plant diseases of national importance: present status and

research and extension needs (Nov. 10-30, 2003)

13. Ecologically sustainable management of plant diseases: status and strategies (March 22-

April 11, 2004)

14. Disease resistance in field and horticulture crops: key to sustainable agriculture (Dec. 10-30,

2004)

15. Regulatory and cultural practices in plant disease management (Dec. 03-21, 2005)

16. Crop disease management: needs and outlook for transgenics, microbial antagonists and

botanicals (March 21 – April 10, 2006)

17. Soil Health and Crop Disease Management (December 02-22, 2007)

18. Role of Mineral Nutrients and Innovative Eco-friendly Measures in Crop Disease

Management (March 22- April 11, 2007)

19. Plant Disease Management on Small Farms (January 03-23, 2008)

20. Seed Health Management for Better Productivity (March 28 to April 17, 2008)

Sl. No.

State Total Sl. No.

State Total

1. Andhra Pradesh 11 13. Maharashtra 23

2. Assam 09 14. Manipur 03

3. Bihar 16 15. Meghalaya 01

4. Chattishgarh 7 16. Nagaland 01

5. Gujarat 37 17. Orissa 12

6. Haryana 3 18. Punjab 04

7. Himanchal Pradesh 34 19. Rajasthan 40

8. Jammu & Kashmir 21 20. Sikkim 01

9. Jharkhand 05 21. Tamil Nadu 10

10. Karnataka 22 22. Uttar Pradesh 55

11. Kerla 05 23. Uttaranchal 60

12. Madhya Pradesh 20 24. West Bengal 16

Total = 416


- 27 -

INFRASTRUCTURE

Wheat Pathology Lab. – General Path, Epidemiology, Toxin, Tissue Culture

Maize Pathology Lab. – General Plant Pathology, Bacteriology

Rice Pathology Lab. – General Plant Pathology

Ecology and Vegetable Pathology Lab. – Ecology, Histopathology, Biocontrol,

Nematodes

Soybean Path. Lab.– General Plant Pathology, Fungicides

Oil Seed Path. Lab.– General Pl. Path., Tissue, Culture, Histopathology, Toxins

Pulse Path. Lab. – General Pl. Path., Phytovirology

Seed Path. Lab. – General Path, Seed Borne diseases

Biocontrol Lab. – Biocontrol & IPM

Molecular Pl. Path Lab. – Population biology & host- pathogen interaction

Mushroom Research – Research & training

Glass houses – 3

Polyhouses – 3

UG Practical Lab – 1

PG Lab – 1

Training Hall – 1

Conference Hall – 1

Office – 1

Huts for Mushroom Production


- 28 -

Research Project (on going)

AICRP – 13

Adhoc Projects – 16

Total budget outlay - > 1000 lacs

Sl. No. Project title Funding

agency

1 All India Coordinated Research Project on Wheat ICAR

2 All India Coordinated Research Project on Rice ICAR

3 All India Coordinated Research Project on Maize ICAR


- 29 -

4 All India Coordinated Research Project on Rapeseed Mustard ICAR

5 All India Coordinated Research Project on MULLaRP ICAR

6 All India Coordinated Research Project on Sugarcane ICAR

7 All India Coordinated Research Project on Sorghum ICAR

8 All India Coordinated Research Project on Biological control ICAR

9 All India Coordinated Research Project on Soybean ICAR

10 All India Coordinated Research Project on Mushroom ICAR

11 All India Coordinated Research Project (NSP) Seed Tech Research ICAR

12 Application of micro-organism in Agriculture and Allied Sector Fungi of

Uttaranchal

ICAR

13 All India Coordinated Research Project on Potato ICAR

14 Integrated Management of Guava wilt ICAR, MM-I

15 IPM in Vegetables ICAR, MM-I

16 Refinement of Technology for Production of specialty mushroom ICAR, MM-I

17 Ganoderma of Uttaranchal: their cultivation and components of

medicinal uses

ICAR, MM-I

18 Multilocational Evaluation on Rice germplasm NBPGR-ICAR

19 IPM NCIPM

20 Rural Bio-resource Complex DBT

21 Study of Pathogenicity & Molecular Variability in Fusarium solani

causing shisham wilt

DBT

22 Centre of Excellence in Agriculture Biotechnology DBT

23 Management of crop performances through control of plant disease

epidemics (Indo-French Program) (Just approved)

CEFIPRA,

France

24 Further studies on the management of Karnal Bunt by eco-friendly

Means

Adhoc

25 Multi-locational Evaluation of the germplasm in Chickpea Adhoc

26 Evaluation of Chickpea germplasm against biotic stress -BGM Adhoc

27 DUS test on forage sorghum Adhoc

28 Net work project on management of Alternaria blight of mustard and

vegetable crops

Adhoc

29 Indo-UK Collaborative Project on oilseeds for transfer of disease and

draught resistant

Adhoc

30 AIC Epidemiology and Plant disease management Adhoc


- 30 -

Total Budget Outlay – > 1000 lakhs

Research Areas – Biological Control, IPM, Shisham wilt, Soil solarization, Population Biology,

Seed pathology, Mushroom etc.

Publication:

1. Books - 33

2. Research Bulletins - 20

3. Research Papers - >1200

4. Conceptual / Review articles - >130

5. Chapters contributed to book - >150

6. Extension literature - over (200)

(Hindi – English)

Annual Review of Phytopathology - 02

Recognition and Awards:

UNO (Rome) – Dr. Y. L. Nene

Prof. M. J. Narisimhan Academic Award (IPS) 5

Jawahar Lal Nehru Award (ICAR) 2

Pesticide India Award (ISMPP) 7

P. R. Verma Award for best Ph. D. Thesis (ISMPP) 2

Other (Hexamar, MS Pavgi, Rajendra Prasad etc.) >20

Uttaranchal Ratana 2

Professional Societies and our Share:

Indian Phytopathological Societies

Presidents – 3

Zonal Presidents – 3

Indian Society of Mycology & Plant Pathology –

Presidents – 3

Vice Presidents – 1

Indian Soc. Seed Technology

Vice Presidents - 3

Science Congress

President (Agriculture Chapter) - 1

National Academy of Agricultural Sciences

Fellows - 3


- 31 -

Future Strategies:

Teaching: Introduction of new courses

Methods in Biological Control

Plant disease and national importance

Integrated plant disease management

Molecular plant pathology

Advances in mushroom production

Research thrust:

• Biological control & ICM (IPM + INM) in different crops/cropping systems

• Disease management under organic farming

• Microbial ecology

• Green chemicals

• Population biology of pathogens (including use of molecular tools)

• Induced resistance

• Exploitation of indigenous edible and medicinal mushrooms

Human Resource Development

Degree awarded

M.Sc. 285

PhD 155

Trainings organized No. Persons trained

Summer schools (ICAR) 5 136

Summer training (DBT) 1 24

International training (IRRI) 1 11 (8 countries)

Under CAS 19 395

Persons training under SGSY on Mushroom Production 1785

Out of above > 750 persons have started mushroom cultivation

Future Goal:

Ecologically sustainable management of plant diseases to ensure both food security &

safety through education, research & extension


- 32 -

Priorities in Seed Pathology and Seed Health Testing Research

(Mrs.) K. Vishunavat Department of Plant Pathology, G.B.P.U.A.&T., Pantnagar-263145 (Uttarakhand)

Priorities in Seed Pathology

Seed Pathology has essentially been a part of seed technology .The science of Seed

Technology has, in the past, been predominantly concerned with two features of seed quality: -

Purity and Germination. Seed pathology which has never been considered an important discipline

in seed technology have only become an integral part of modern seed technology in the last

quarter century. Reason being

Seeds are both the vectors and victims of diseases.Seed is often produced in one country,

processed and packaged in a second and sold and planted in another. With this movement of

seed comes an increasing danger of the spread of seedborne diseases.

Ways of losses due to seed borne diseases:

Short term or immediate

The first crop produced by the infected seed lot, may cause reduced germination, poor

seedling vigour, abnormal seedlings and other damage to crop at any stage of growth from

seedling to harvest and storage or---

Long term losses

Such losses are not always restricted to the fields where diseased seed when is sown rather

adds secondary inoculum which may be carried by wind, rain, irrigation water, machinery, insects,

animals and man spreading the disease long distances from the original source of infection.

Research Priorities in Seed Pathology

In Seed Pathology the major emphasis has been on cataloging seed-borne microorganisms for

first two decades. Over the period of 1982 - 1994, almost a quarter, approximately 2000 citations

simply catalogue the presence of microorganisms on seed.The type of cataloging research

identified focuses more on fungi than it does on bacteria and viruses. Standardization of detection

techniques for seed borne bacteria and viruses .There is need to focus research more in the area

of seedborne bacteria and virus detection and identification since this area has been neglected

due to the lack of adequate assays.

(1) Establishment of inoculum thresholds

The importance of research in the area of establishing research thresholds for seed borne

diseases, for these thresholds will be fundamental if the management of seedborne disease is to

be successful. Economic significance of seed-borne diseases to the assessment of seed borne

inoculum is desirable.

(2)Seed Treatment Technology


- 33 -

A wide variety of chemical, biological, physical, and mechanical approaches have been

used to eliminate pathogens from the internal and external portion of seeds, and to help protect

seeds from soil borne pathogens.

(a) Chemical seed treatment

Chemical fungicide treatments such as Captan and Thiram are still the most widely used

products in the industry and research into better ways to apply and to reduce the effective rates of

these chemicals must continue.

(b) Alternatives to chemical seed treatment

A wide range of systemic fungicides which control seedborne diseases however, under

conditions of high disease pressure, may at times fail to control the diseases. Certain such

chemicals have the potential to be harmful to the soil and non soil environment or are phytotoxic to

the seed and the emerging seedling. This compels to look upon alternative ecofriendly methods of

treating seed to control disease(s)

(c) Physical seed treatment

Hot water treatment of seed, acid treatments or other methods, continue to be a standard

method of pathogen elimination in seeds.These methods are more ecofriendly and effective

compared to chemical treatments (particularly hot water) and effective; however, they can cause

the loss of seed viability. There is need to standardize such technologies so as to effectively

manage the seed borne diseases .

(d)Biological seed treatment

Identifying, testing, and developing biological seed treatments appears to be an area where

much research effort is occurring and will continue in the future. The use of naturally occurring

beneficial fungi and bacteria to control other fungi and bacteria is not a new idea; however, due to

the renewed interest in the environment and the establishment of worker protection standards,

research in this area is going through a renaissance.Among these are the common soil inhabiting

bacterial genera Psedudomonas, Enterobacter, Erwina, and Bacillus. The fungi Trichoderma and

Gleocladium along with the actinomycete Streptomyces are also being studied carefully as to their

seed treatment efficacy.Cotton (Gossypium hirsutum) seed with the G-4and G-6 strains of

Gleocladium virens and the GB03and GB07 strains of Bacillus subtilis suppress the incidence and

the severity of Fusarium Wilt of cotton(Gossypium hirsutum) in soil infested with Fusarium

oxysporium f. sp. vasinfectum and Meloidogyne incognita under greenhouse conditions.

(i) Considerations for biological seed treatment

The inoculum density of the biocontrol agent must be adequate to suppress disease under

field conditions and high levels of disease pressure.

The formulation of the biocontrol agent must be one that allows for an adequate shelf life

and it must be compatible with other biocontrol agents as well as chemical seed and soil

treatments.Research should be focussed on finding new and more efficient biocontrol based seed

treatments as well as refining and increasing the efficiency of the current crop of biocontrol agents.


- 34 -

Historical development of Seed Health Testing

The first seed testing station was established by Nobbe in Saxony in1869. Nobbe in his

1876 publication Samenkunde mentions smut balls and sclerotia but does not describe any

method for their detection except visual examination of the seed.The first seed health test to

appear was developed by Hiltner working in Germany in 1917.The most notable of the early

pioneer in seed health testing was with out doubt Dr. L.C .Doyer .The most notable of the early

pioneer in seed health testing was with out doubt Dr. L.C .Doyer and Paul Neergarad, also known

as father of seed pathology, who coined the tem seed pathology as an important discipline in Plant

Pathology .

In 1918, first seed health testing laboratory was established at the Government Seed

testing laboratory in Wageningen, The Netherlands. Doyer was the first official Seed pathologist .

She was the first chairperson of the ISTA Plant Disease Committee, a position she held until her

death in 1949.At sixth ISTA congress, at Wageningen, she presented her proposal for recording

Sanitary conditions of Seed on the International rules of Seed Testing. Later Dorph-Petersen, the

first ISTA president, presented a report in International Seed Testing Conference held in 1921 in

Copenhagen, on Remarks on the Investigations of the Purity of Strain and Freedom from

Disease.

At the 1924 congress held in Cambridge, Genter spoke on the subject Determination of

plant diseases transmitted by seed.

The first International Rules for Seed Testing were published by ISTA in 1928. This

document contained a special section on Sanitary Condition in which special attention was

recommended for Claviceps purpurea, Fusarium, Tilletia, and Ustilago hordei on cereals;

Ascochyta pisi on peas, Colletotrichum lindemuthianum on beans and Botrytis, Colletotrichum

linicola, and Aureobasidium lini on flax.

Seed Health testing

Methods for seed health testing such as, incubation methods, grow out test and other

conventional methods often vary from one laboratory to another which is inadequate for

comparative seed health testing.

In 1957, the Plant Disease Committee established a comparative seed health testing

programme aimed at standardizing techniques for the detection of seedborne pathogens.

Subsequent symposia have focused on Seed Health Testing - Progress towards the 21st

Century (Cambridge, UK 1996) and most recently in August 2003, Disease thresholds and their

implication in seed health testing (Ames, Iowa).

Recent Advances in Seed Health Testing procedures

Today, seed health testing is routinely carried out in most countries for domestic seed

certification, quality assessment and plant quarantine. The first PDC Seed Health Symposium was

held in Ottawa, Canada in 1993 and focused on quality assurance in seed health testing. The

demand for better seed quality of conventional varieties and transgenics, greater sensitivity in


- 35 -

detecting seedborne pathogens and shorter turn around times for seed testing is forcing seed

health testing laboratories to incorporate new technologies to meet this challenge globally.

Technological improvements have increased test sensitivity permitting detection of very low

levels of inoculum using rapid indirect tests on bulked samples of 1000 -10,000 seeds.Seed health

testing has undergone significant changes. Seed health testing was primarily directed towards

fungi and relied on incubation and identification, or grow out tests for detection of these pathogens

on seed. Such tests are labour intensive and in some cases require high levels of infection before

they can be detected. Sousa Santos et al. (1997) used PCR to detect the presence of Clavibacter

michiganensis pv michiganensis in infested tomato seed lots.

Detection technology for seed borne bacteria and viruses

Serological-based seed assays, such as the enzyme -linked immunosorbent assay

(ELISA), continue to be used with some success for fungi and bacteria.

However, they lack the specificity and sensitivity needed to detect many seedborne viruses

(McGee, 1995).

About 20% of the known plant viruses are transmitted through seeds of infected plants and

in many cases the rate of transmission is very low. Seed transmission rate of maize chlorotic

mottle spot virus was 17 in a total of 42,000 plants or 0.04%( Jensen et al. (1991).The seed

transmission rate of maize dwarf mosaic was one seed in 22,189 (Mikel et al.,1984).

The incredibly low rate of seed transmission of these pathogens, and the fact that plant

viruses are strict obligate parasites, most conventional types of seed assays used to detect fungi

and bacteria are useless.

Kohnen et al. (1992) employed molecular technology to detect pea (Pisum sativum)

seedborne mosaic virus.

With the introduction of DNA-based assays and polymerase chain reaction (PCR)-based

assays, researchers have the ability to detect very minute amounts of a specific DNA sequence on

the surface of or internal to a seed.

Specificity has also improved through the use of antibiotics and other agents in selective

media for recovery of pathogens from seed. Biological reagents such as antibodies and DNA

markers also contribute to improve seed health assays.

DNA-based polymerase chain reaction (PCR) method has been developed as an

alternative to grow- out -test. This test holds great promise for the future of seed health testing.

Still very much in the development stage, PCR assays have high sensitivity and specificity

and often require as little as 24 or 48 hours to complete. They are applicable to a wide range of

pathogens and can be used to separate closely related species.

Challenges Ahead


- 36 -

In last 35 years since the first publication of the Working sheets by ISTA only 64 sheets

have been published. Many are now out-dated due to advances in seed testing technology and

microbiological techniques. Others are of little or no significance in the international movement of

seed.

Future thrust

Thus, there is a need on the part of the seed industry, trade and regulatory bodies alike to

have sound, reproducible and validated methods for the detection of seed-borne pathogens.

Standardized assays that allow seed produced anywhere in the world to be monitored for

some minimum level of health quality.

Inoculum threshold level should be worked out for seed borne diseases of significance for

better management of the diseases. The Plant Disease Committee must be prepared to ensure

reliable, reproducible and validated methods for seed health testing for use by both the seed

industry and regulatory bodies. There is need to come up with the ready- to- use kits for detection

of seed borne pathogens with standardized protocols.


- 37 -

Epidemiological Approaches to Disease Management through Seed Technology

(Mrs.) K. Vishunavat

Department of Plant Pathology, G.B.P.U.A.&T., Pantnagar-263145 (Uttarakhand)

Introduction

The quality of planted seeds has a critical influence on the ability of crops to become

established and to realize their full potential of yield and value. A complex technology is required to

ensure high standards of seed quality that involves-Producing, harvesting, processing, storing and

plating the seed.

Throughout this process, careful handling to avoid mechanical injury and protection from

adverse environmental conditions, pests, and diseases are imperative. No one factor is

necessarily more important than another with respect to maintenance of seed quality but almost all

seed crops require some measure of disease control. The knowledge of the epidemiology of seed

diseases can promote disease management through modern Seed technology.

Disease impact on seed management systems

Seed Pathology emerged as a sub-discipline of plant pathology from analysis of seed

quality in the early part of this century.

Since than a world wide process of cataloguing microflorae of seeds have been associated

approximately 2400 microorganisms with the seeds of 383 genera of plants. Concurrently

epidemiological studies were carried out on the seed-borne phase of economically important

diseases e.g. bacterial blight of beans, smuts of cereals and Stewart’s wilt of corn. There are three

environments in which seed exists:

A. THE SEED PRODUCTION FIELD

B. HARVESTING, PROCESSING AND STORING AND

C. THE PLANTED FIELD

A. THE SEED PRODUCTION FIELD

Disease can have an indirect effect on seed in the production field in that the seed is not

associated in any way with the pathogen but other plant parts are diseased; this renders the plant

physiologically ill equipped to complete the development and maturation of the seeds. Direct

effects means that the seed itself is diseased, thus the viability and appearance of the seed is

affected and /or the pathogen is transmitted to the plant grown from the seed.

(a). Seed infection in Seed production field

Seed infection can occur during the three distinct physiological phases in the seed production

field; anthesis, which covers the period from initiation of floral primordia to fertilization of the

embryo; seed development, which represents the period during which the fruiting structures grow

and develop to full physiological maturity; and seed maturation, which is the dry down period that

continues until the seed is harvested.


- 38 -

Each phase has unique characteristics with respect to the epidemiology and management of seed

disease.

(b). Management of seed borne diseases in seed production field

i. Elimination of Inoculum Sources

ii. Disease management during anthesis

iii. Disease management during seed development

iv. Disease management during seed maturation

i. Elimination of inoculum, sources

The first opportunity for management of seed diseases is to eradicate or reduce pathogen

inoculum in the seed production field for e.g. Removal of crop residue (Phomopsis seed decay of

soybean). Removal of Infected weeds as perennial source of contamination (Brassica seed fields

by X. campestris pv. Campestris in Brassica ) . Destruction of infested seeds, the primary source

of inoculum, by burning or by vacuuming fields (for ergot in perennial grass seed production

fields).

ii. Disease management during anthesis

The optimal time for Fusarium moliniforme infection of maize kernels by silk inoculation

occurs when silk begin to senesce. The infection process also may be influenced by environment.

rain and warm temperature following anthesis resulted in increased grain mold contamination of

caryopses of sorghum.Knowledge of the mechanism and enviornmental influences on infection at

this growth stage has been used to advantage in disease management. Several group of

pathogens including smuts, ergots, viruses, and nematodes infect seeds during anthesis.a unique

feature of infection at this growth stage is the facility for infection of embryos and other internal

seed tissues. Embryo invasion by viruses from the mother plant is dependent on short-lived

cytoplasmic connections to the male or female gametophytes. The potential for biological control

during antesis was demonstrated by inoculation of wheat florets with a stain of C. purpurea that did

not biosynthesize ergot alkaloids, but had sufficient parasitic vigor to displace alkaloid- producing

strains.

iii. Disease management during seed Development

Seed infection during seed development can occur by invasion through natural openings

including the funiculus and micropyle, by direct penetration of the seed or caryopsis, or from pods

or freshy fruits. Infection also can be strongly influenced by environment. Osorio & McGee showed

that exposure of soybean pods to frost at --4.5 or -250c immediately before physiological maturity

predisposed seed to infection by Fusarium graminearum and Alternaria alternata but reduced seed

infection by Phomopsis longicolla .More over there are numerous reports of fungicide applications

in seed production field to control seed borne pathogens. But more strategically these studies are

rarely considered in disease epidemiology.The pod infection occurs at any time from flowering

onwards for number of seed borne pathogens e.g. in Phomopsis seed decay of soybeam ,

X.campestrisis pv. Vignicola but the fungus will not infect seeds until seed maturation begins. This

disease epidemiological aspect may be used as predictive methods of fungicidal application.


- 39 -

Cultural practices provide options to manage seed diseases in the production field; adjustment of

planting time , crop rotation , elimination of weed hosts , irrigation practices etc.Bean intercropped

with maize than on bean grown alone showed higher seed borne population of P.syringae pv.

phaseoliocola( Mabagala and Saettler 1992).Biological control of seed infection during seed

development was demonstrated by the reduction of aflatoxin B1in the cotton seed after

simultaneous inoculation of wounded cotton ball with toxigenic and atoxigenic strains of

Aspergillus flavus.

iv. Disease management during seed maturation

Certain fungi, such as Fusarium moniliformae in corn, Botrytis, Alternaria ,Cladosporium sp

commonly infest the soil and crop residues and may invade seed under prolonged periods wet

weather at seed maturation growth stage and cause seed discoloration and loss of viability.

Weathered seed experience physiological deterioration as well as pathological damages.

Effective control of disease during seed maturation is achieved by harvesting the seed as soon as

it is sufficiently dry.

Planting dates may be manipulated to avoid conditions favorable for seed infection as in

the case of Phomopsis seed decay of soybeans in which the chances of temperature and humidity

conditions favorable for seed infection occurring are much lower for late compared to early planted

crops ( McGee 1987) .There are few examples for breeding specifically for resistance to infection

of the seeds.e.g. a genotype resistance to Phomopsis seed decay and sources of resistance to

Cercospora kikuchii , the cause of purple seed stain of soybean have been identified( Brown et al

1987, Roy 1982) . Grain Hardness ,ergosterol content, and tennins have been implicated in

resistant to moulding of Sorghum grains ( Bosman et al 1991)

B. HARVESTING CONDITIONING AND STORING

The harvesting process provides opportunities for pathogen structures , such as sclerotic ,

nematode soil peds, and teliospores to contaminate seed lots.

This type of contamination can be minimized by setting the harvesting equipment to avoid contact

with the siol and to eliminate physically altered seeds or pathogen structures. Seed when passed

over air screen cleaners and gravity separators help to reduce the fungal sclerotia or infected

seeds ( Phomopsis infected seeds of soybean and plant debris).Paulsen 1990 used a computer

vision system to detect purple stained soybean seed infected with Cercospora kikuchii with 91%

accuracy.Walcott developed an ultrasound signal to detect asymptomatic infection of Aspergillus

and Penicillum spp. in storage in soybean.

a. Disease management during storage

Storage fungi (Aspergillus and Penicillum sp.) invade grains and seed stored at moisture

contents in equilibrium with ambient relative humidity ranging from65-90%and can cause major

losses in seed viability.

Effective management of storage fungi invasion is obtained by drying of seeds below the

minimum moisture contents for storage fungi invasion and maintaining this moisture content by

aeration.


- 40 -

The effectiveness of this practice often breaks down, however, when seed is held in

storage facilities with poor environmental controls.

A few examples of management of storage fungi during seed storage are:

Soybean oil applied to reduce growth of storage fungi in maize and soybeans

(McGree1988).Insect and storage fungi management by mineral oil and soybean oil treatment in

beans ( Hall and Harman 1991)

The fungicides thiabendazole and Iprodione supress growth of storage fungi in stored corn

( White and Toman 1994).The potential for natural products ( Flabonoids and Isoflabonoids, and

their derivatives ) to control storage fungi for seed of bean and soybean is demonstrated by

Weidenborner et al 1990.

b. Seed Health testing

Seed health testing is used primarily to manage diseases by inoculum threshold, to

determine the potential effect of seed borne inoculum on stand establishment in the planted field,

and to meet the requirements for phytosanitary certification of seed lots to be exported. For seed

health testing following methods are routinely used:

c. Field inspection

It requires that the seed production field be examined for symptoms of a disease on

growing plants. The method is based on the assumption that incidence of infection on plants and

seed are related. Although there are few diseases where this relationship has been validated,

procedure remains the back bone of Phytosanitary certification in many countries.

d. Direct seed assay

Seed may be examined visually for clear signs or symptoms expressed on the seed

surface.Another approach is to soften seed tissues and then examine the internal tissues of the

seed microscopically for mycelium of the pathogen.

e. Incubation test

It requires that the seed be subject to conditions that select for and optimizegrowth of

target pathogen. Assay usually require pretreatment with a chemical to surface disinfest the seeds,

followed by incubation on blotters or culture medium under precisely defined environmental

conditions.

f. Grow out test

Seed are planted in the field or green house in the absence of other inoculum sources.

Seedlings are examined for symptoms produced by the seed borne pathogens. The procedure

requires much time, space, , and labour. It also tends to lack sensitivity, but it can predict well the

extent of seed transmission of Pathogens in the planted field.

g. Serological assays

Serological assays for seed borne pathogens were first reported in 1965 with an

agglutination test for Pseudomonas phaseolicola in beans( Guthrie at al 1965)and double diffusion

assay for barley stripe mosaic virus ( Hamilton 1965).The introduction of ELISA to plant pathology


- 41 -

in 1976 stimulated rapid advances in the use of serological assays for seed borne pathogens.With

diagnostic kits now available from the private sector for ELISA and its variants, serology has

become cost- effective and practical to detect seed borne pathogens through out the world .

However, a well known weakness in serological tests has been the propensity to detect

false positive caused by the binding of antibodies to epitopes, which may no longer be a propagule

of the pathogen which can be overcome by combining serological assay with a viability test.

h. DNA hybridization assay

DNA hybridization assay use a DNA probe that is complementary to DNA in the genome of

the plant pathogen.The probe is applied to a DNA extract from seed and hybrizied material

detected by dot blot hybridization assay. The technique has successfully used to detect

Peronosclerospora sorghi and P. sacchari in corn ( Yao et al 1990) Pseudomonas syringae pv.

Phaseolicola in bean seeds .

C. THE PLANTED FIELD

a. Seedling emergence and establishment

There are sound epidemiological bases to establish relationship between seed borne

pathogens and seed quality and this impress upon the use of seed treatment to improve seed

vigor and reduce the seed borne inoculum for better plant stand in field.

b. Transmission of seed borne pathogens: transmission of seed borne pathogens by following

factors:

i. Epidemiological factors affecting seed transmission:

Seed transmission for some seed borne pathogens is well defined. Few most promising

fungal pathogens such as Ustilago tritici, Neovossia indica,Telletia caries, Peronospora parasitica

in rape seed mustard, and many seed borne bacteria and viruses.

Physiological factors may affect the capacity of the seeds to transmit pathogens. Few

examples are:Downy mildew pathogen in maize can be transmitted when seeds are freshly

harvested, but not once the seeds are dried ( Mc Gee 1988.) Arabis mosaic nepovirus is

transmitted inefficiently in Nicotiana seed , because the virus reduce seed germination

Environmental factors play a major role in the efficiency of seed transmission of plant

pathogens.

The seed borne inoculum of Alternaria brassicae or A. brassicicola in rape seed mustard

reduces with the seed storage and at temperature above 35 0C the fungus is auto-eliminated in

tropical conditions. In Cabbage seedling disease caused by Alternaria brassicicola for e..g does

not occur below 150C in heavily infected seed lots .

ii. Inoculum threshold

Inoculum threshold have been established on a sound epidimiological basis for only a few

pathogens, including Phoma lingum in Crucifers, Pseudomonas syringae pv. phaseologicola , and

lettuce mosaic virus. For many seed borne pathogens, inoculum threshold is determined either

arbitrarily or by field observation data ( Schaad 1988). To be of value, however the threshold


- 42 -

should be established in well designed experiments. The first step is to have a suitable seed

health assay. But very few methods are thoroughly researched to determine if they are specific ,

accurate reproducible, and practical.

The next step is to plant seed with different infection level in the field and establish a

correlation with plant infection.

For diseases that have no repeating cycle of infection such as seedling infecting smuts,

strong correlation between seed infection and field diseases can usually be expected.

It is much more difficult to establish inoculum threshold for diseases for which secondary

infections occur from other inoculum sources.

iii. Certification Programme

This programme exists to protect against spread of disease by seeds with in geographic

regions. In this programme seed lots must meet certain minimum standards of quality which

includes specific diseases, before seed can be marketed.

This programme uses knowledge of the epidiomiology of the disease that includes laboratory

assays of the seeds and field controls.

iv. Phytosanitory certification

The system has some serous problems, however phytosanitary regulations are determined

by individual countries and often are made on the basis of a poor understanding of the economic

losses that introduction of particular pathogens could potentially incur; minimal knowledge of

relation ship between tolerances in seed assays to risks of transmission of the pathogen to the

planted crop; and lack of standardized testing protocols.

v. Germplasm

International Agriculture through out the worlds are taking steps to minimize the

introduction and spread of exotic seed borne pathogen by seed exchange.

Several international centers have implemented programs to manage seed borne pathogen

through monitoring pathogens in the seed lots, modification of seed production practices to

minimize the infection or transmission of pathogens by seed and use of seed treatment.

vi. Seed treatment

Chemical, physical and biological seed treatment has dramatically changed in the last 20

years. As a result of new fungicide chemistry, advances in biological control and environmental

regulation that have either banned or restricted the use of fungicides. Fungicide seed treatment

remains the most widely used practice and established materials such as captan and thiram still

are the mainstay of seed treatment chemistry. Several systematic fungicides such as metalaxyl,

iprodione and triadimenol are being used for management of deep seated infections in seed and

subsequent protection of seedling against infection.

Chemical control of seed borne bacteria has limited success, either because of lack of

control of internal inoculum or phytotoxicicity to the seeds. Antibiotics, applied in polyethylene


- 43 -

glycol (PEG), reduced infection by Xanthomonas campestris pv. phaseoli in bean seeds, but were

phytotoxic.

Heat treatment, hot water treatment or microwave heating has successfully reduced seed

borne infection.

There is numerous report of potentially valuable biological control microorganism for seed

treatment but the developmental process to bring these into commercial practice is long and

arduous.Mode of application of seed treatment with chemicals is also an important area to be

discussed.

Traditional dust or slurry application of seed treatment fungicides are now regarded as

inefficient in environmentally hazardous.

Application of chemical or bio pesticides in film coatings or pallets reduces the loss of

material and allows the delivery of multiple products.Bio- protectants and chemical pesticides

provided effective control when added together in solid matrix priming.

vii. Resistance

No example could be found of resistance especially to seed transmission of fungal or

bacterial pathogen in the planted field.However cultivar specific resistance to seed transmission

has been reported for BSMV in barley, PsbMV in peas, SMV in soybeans and AMV in alfalfa.

Conclusion

A review of the literature on seed pathology over the period (1982-94) indicates that almost

a quarter of approximately 2000 citations simply catalogued the presence of microorganisms on

seed. These purely descriptive commentaries do not address the potential for crop damage by

planting diseased seeds or the management of seed borne diseases.

Indiscriminate cataloguing of seed-borne microorganism on seeds obscures seed-borne

pathogens that might be of genuine economic importance.Viruses and bacteria that traditionally

have been neglected for lack of adequate assays.

Priority should be given to pathogens that meet the criteria of limited distribution and of

potential economic importance, as in the class of maize chlorotic mottle.

Research on inoculum thresholds is both complex and expensive, but it is so fundamental

to realistic and effective management of seed transmission of plant pathogens that little

improvement in the seed health system worldwide will be possible unless priorities in seed

pathology research are changed.

“Guidelines for safe movement of germplasm”, sponsored by the International Board for

Plant Genetic Resources, can lead to management system for seed diseases that protect against

the spread of economically important plant pathogen without posing unnecessary barriers to the

movement of seeds.


- 44 -

Seed Treatment–A New Challenge in Organic Seed Production

R.L. Agrawal Ex-Director, Uttaranchal State Seeds & Organic Production Certification Agency

Diseases are caused by pathogens that may occur, in the soil, adhere to the seeds/

planting material, or carried in the wind, or by the insect vectors. In the case of seed borne

diseases, the pathogens are carried either on the surface of the seed or within it. Seeds are

usually treated with synthetic chemicals to provide a general protective cover or with some specific

chemicals to combat specific seed borne diseases. The organic crop husbandry standards

however prohibit the use of synthetic chemicals in any form or for any purpose, and hence the

seeds meant for organic production can not be treated with these chemicals. Organic Production

Standards require use of home grown untreated seeds produced under organic management for

organic crop husbandry. Given the prohibition or restrictions on most seed dressings this indeed is

a challenge that would need to be met.

The various approaches that need to be adopted to meet the challenge are discussed

below.

Produce Healthy Seeds

The foremost emphasis must be placed on the production of healthy plants – healthy

seeds/ planting material which is capable of fending - off many of the common plant diseases.

Produce a healthy soil by managing organic matter and enhancing soil life, including

microorganisms.

Crop rotation that helps control spread of diseases.

Optimize nutrient availability by green manure, composts, and other bio-fertilizers, including

the use of nitrogen fixing crops.

Use of healthy seeds, resistant crop varieties etc.

Adopt Good Agricultural Practices (GAP), including management of crop harvest,

threshing, drying and storage etc.

Adopt sanitary measures, including field sanitation. Field sanitation through the removal of

diseased debris, weeds, alternate and collateral hosts are very effective in containing plant

diseases.

Dry and cool storage of seeds. Good sanitation of seed storage houses.

Seed treatment

Seeds and planting materials can be treated when it becomes imperative to do so, and that

when there is no other alternative. A careful choice however would need to be made amongst

permitted methods/ substances for seed treatment in organic crop husbandry.

Physical methods: Wherever feasible, the seed treatment with hot water, soaking the seeds in

cold water, solar treatment followed by soaking seeds in water, seed cleaning, and sieving

methods should get preference over other methods.


- 45 -

Plant extracts: Plant extracts can be used for seed treatment. The difficulty here however is that

much work has not been done in this regard. A lot of experimentation and standardization would

need to be done in this regard.

Mineral Origin: The various substances of mineral origin permitted in the organic standards for

crop protection can be used for seed treatment. Standardization would need to be done in this

regard.

Direct Biological Control Methods: In recent years much emphasis has been placed on the

development and standardization of biological control methods. A large number of bio-agents to

combat diseases are now commercially available.


- 46 -

Strategies for Regulation of Seed Borne Diseases in Organic Farming

R.L. Agrawal Ex-Director, Uttaranchal State Seeds & Organic Production Certification Agency

Pest and diseases are generally not a significant problem in well managed and well

established organic farms. It is only when they go out of hand that certain specific control

measures may have to be undertaken. Disease control on organic farms is based on a range of

crop husbandry practices which promote stability and balance between crops and their diseases.

Natural Crop Protection Strategies

Natural crop protection practices are no backward looking practices. They are composed of

traditional, local and scientific knowledge systems, each enriching the other. Successful

application requires both a sound understanding and skills needed to manage these knowledge

systems in the complex systems which farms are. It may however be necessary to develop site-

appropriate strategies for crop husbandry.

Knowledge of Agro-Eco System

Knowledge of agro-eco system helps the farmers to make correct observations and

decisions in respect of the following:

Seasonality of diseases, stage of crop development when the plants are most susceptible

to diseases.

Conditions which support disease development (weather conditions).

Which role do space and time play? Diversion over time here means discontinuity of

monocultures; crop rotations, use of short duration varieties, manipulation of sowing and

harvesting dates. Diversity in space means use of varietal mixtures, resistant cultivars, crop

mixtures etc.

Linkages that exists between the different components of an agro-eco system. How can

they be manipulated with due regard to the farmer’s production objective.

Crop Growing Conditions

The crop growing conditions needs to be optimum. These include,

Well structured soils.

Fertile soils, and balanced crop nutrition.

Avoiding moisture stress.

Preventive steps, such as, soil flooding, solarization etc., wherever needed.

Timely crop husbandry operations.

Field sanitation.

Healthy Soils and Healthy Plants

The health of a plant is directly correlated with diseases. Healthy plants under optimal soil

conditions and balanced nutrition are better able to actively resist diseases. Soils with high organic

matter and high biological activity help maintain stability of soil ecosystem and balanced crop


- 47 -

nutrition owing to high microbial activity. The value of organic manuring for fungal disease control,

and in particular the use of compost has been confirmed during last few decades. In some soils

high levels of organic matter and biological activity are directly associated with low levels of

disease incidence. Such soils have higher populations of bacteria and actinomycetes. Mycorrhizae

play a particular role in plants defense mechanism. They assist in disease control by forming a

protective fungal jacket around the plant root. Plants with roots affected by mycorrhizae known to

be less disease susceptible than without, and are also more resistant to nematodes.

Natural Rhythms and optimal planting season

An outbreak of diseases is usually associated with a particular stage of development of

host plant. This should be observed locally to reach right decision.

Crop Rotation

It is believed that species diversity leads to a greater stability in the agro ecosystem and

therefore reduces risk from sudden outbreaks of specific diseases.

Host Plant Resistance and Tolerance

Plants in natural environments depend entirely on their own defenses. In traditional farming

systems farmers have long been familiar with a wide choice of land races/ local cultivars which are

appropriate to their needs.

Field Sanitation

Sanitation includes removal and destruction of plants affected by seed borne diseases, and

of the plant residues infected by diseases.

Other Disease Control Measures (Supplementary Measures)

At organic farms, frequently natural controls may be all that is required. Once all steps to

create an optimal environment for plant growth have been taken, and there are circumstances

where the disease incidence is significant to cause economic damage supplementary intervention

may be necessary. The organic standards permit the use of physical methods, including the use of

heat; and the use of products that are prepared at the farm from local plants, animals and

microorganisms, subject to conditions imposed, if any (Table 1).

Table 1 Crop Protectants and Growth Regulators

Substances, Description, compositional requirements

Conditions for use

PANT AND ANIMAL ORIGIN

Algal preparations

Animal preparations and oils

Beeswax

Chitin nematicides (natural origin)

Coffee grounds

Dairy products (milk, casein, buttermilk etc.)

Gelatine

Lecithin

Natural acids (vinegar)

Neem

Plant oils


- 48 -

Plant preparations

Plant based repellents

Propolis

Pyrethrum The synergist Piperonyl butoxide is prohibited

Quassia

Rotenone

Ryania sabadilla

Tobacco tea (pure nicotine is forbidden)

MINERAL ORIGIN

Chloride of lime

Clay (bentonite, perlite, vermiculite, zeolite)

Copper salts (e.g. sulfate, hydroxide, oxychloride, octanoate)

Maximum 8 kg /ha. per year (on a rolling average basis)

Diatomaceous earth

Paraffin

Lime sulfur

Potassium bicarbonate

Potassium permanganate

Quicklime

Silicates (e.g. sodium silicates, quartz)

Sodium bicarbonate

Sulfur

MICROORGANISMS

Fungal preparations

Bacterial preparations (e.g. Bacillus thuringiensis)

Release of parasites, predators and sterilized insects

Viral preparations

Criteria to evaluate additional inputs to organic agriculture

1. Necessity. Input must be necessary to use e.g. on specific crops, in specific regions or

under specific conditions from the viewpoint of yield, product quality, environment safety,

human and animal welfare.

2. Nature and mode of production. The origin of input should usually be organic – vegetative,

animal, microbial; or mineral. The ingredients of the input may undergo processes such as,

mechanical, physical, enzymatic, action of microorganisms. The collection of raw materials

shall not affect the stability of the natural habitat nor affect the maintenance of any species

within the collection area.

3. Environment. The input shall not be harmful or have a lasting negative impact on the

environment. Nor the input shall give rise to unacceptable pollution of surface or ground

water, air or soil. Input shall not contain harmful manufactured chemicals. All inputs shall be

degradable to CO2, H2O and or to their mineral form. Inputs with a high acute toxicity to

non-target organisms should have a maximum half-life of 5 days. Natural substances used

as inputs which are not considered toxic do not need to be degradable within a limited time.

Mineral inputs should contain as few heavy metals as possible.


- 49 -

4. Human health and quality. Inputs shall not be harmful to human health, and shall not have

negative effects on the quality of the product.

5. Ethical aspects – Animal welfare. Inputs shall not have a negative influence on the natural

behavior or physical functioning of animals kept at the farm.

6. Socio Economic Aspects. Consumer’s perception. Inputs should not interfere with a

general feeling or opinion about what is natural or organic.

General guidelines

No single strategy is likely to be successful on its own. Effective control relies on the

effective interactions between many factors.

1) Adopt a variety of cultural methods to control plant diseases; including Organic manuring

and crop nutrition, rotation design, and choice of crop varieties appropriate to location.

2) Adopt measures, such as, crop isolation where there is a danger of contamination from

neighboring fields, and rouging of diseased plants affected with seed borne diseases with

in fields. Insect borne viruses are best controlled by controlling the transmitting insects.

3) Adopt direct biological and mechanical controls. Use plant extracts to treat the soil or the

planting material. Air bone diseases can be treated by the use of foliar sprays and other

permitted products.


- 50 -

Seeds: Intellectual Property

H.S. Chawla Department of Genetics and Plant Breeding, G.B.P.U.A.&T., Pantnagar-263145 (Uttarakhand)

The WTO was established on 1st January 2005 and is responsible for making and

enforcing rules for trade between nations. WTO marks a major change in global trade rules. As an

organization, it replaces the General Agreement on Tariffs and Trades (GATT), which had been in

existence since 1947. The Eighth Round of Multilateral Trade Negotiations under GATT, which

started in Uruguay in 1986, was concluded in 1994, leading to the creation of WTO as the new

permanent international trade organization. The role of WTO is much more extensive than that of

GATT, which dealt with trade in goods. Apart from goods, the two other broad areas that WTO

covers are services and intellectual property, which previously belonged to the domestic domain.

Accordingly, WTO administers not only the Multilateral Trade Agreements (MTAs) in goods but

also the General Agreement on Trade in Services (GATS) and the Agreement on Trade Related

Aspects of Intellectual Property Rights (TRIPS), which came into existence with WTO. All the

agreements annexed to the Agreement establishing the WTO were signed as part of a package

deal. Member countries did not have the option of choosing some and rejecting others. Another

important difference with the erstwhile GATT is that WTO has a stronger compliance mechanism

than the GATT. A member’s failure to meet the obligations can invoke retaliation across

agreements and sectors (Chawla, 2007a).

As one of the WTO agreements, TRIPS is binding on all member countries of WTO. TRIPS

aims at establishing strong minimum standards for intellectual property rights (IPRs). IPRs can be

defined as the rights given to people over the creation of their minds. They usually give the creator

an exclusive right over the use of his/her creation for a certain period of time. Intellectual property

includes copyrights, trademarks, geographical indications, industrial designs, integrated circuits

and trade secrets (Chawla and Singh, 2005). The protection of IPRs is binding and legally

enforceable.

IPRs have been created to ensure protection against unfair trade practice. Owners of IP

are granted protection by a state and/or country under varying conditions and periods of time. This

protection includes the right to: (i) defend their rights to the property they have created; (ii) prevent

others from taking advantage of their ingenuity; (iii) encourage their continuing innovativeness and

creativity; and (iv) assure the world a flow of useful, informative and intellectual works.

Patents

A patent is a government granted exclusive right to an inventor to prevent others from

practicing i.e. making, using or selling the invention. A patent is a personal property, which can be

licensed or sold like any other property. The purpose of a patent is to encourage and develop new

innovations. The Patent Law recognizes the exclusive right of a patentee to gain commercial


- 51 -

advantage out of his invention. There are three criteria to issue a patent for the innovation (Chawla

and Singh, 2007).

i. Novelty: The inventor must establish that the invention is new or novel. The novelty

requirement refers to the prior existence of an invention. If an invention is identical to an

already patented invention, the novelty requirement is not met, so a patent cannot be issued.

ii. Inventiveness (Non-obviousness): It is an invention and not merely discovery. It is non obvious

to one skilled in the field. The non-obvious requirement refers to the level of difficulty required

to invent the technology. If an invention is so obvious that anyone having an ordinary skill

would have thought of it, then it does not meet this requirement.

iii. Usefulness (Industrial application): It has a utility or is useful for the society. The useful

requirement refers to the practical use of invention. If an invention provides a product that is

required or needed in some manner, then it meets this requirement

In the patent adequate disclosure should be made so that others can also work on it. It

should have the features: i) be a written description; ii) enables other persons to follow; iii)

adequate and iv) deposit mechanism.

The present law, Patents Act 1970, amendment 2005 is effective from January 1, 2005.

Product patents on all items including food, agro-chemical and pharmaceuticals have also been

allowed making the Patents Act fully TRIPS compliant.

The patent system was developed as a means to reward inventions which would be useful

to the society. However, in order to ensure the interests of society, as per the Indian Patents Act,

certain things have been excluded from the purview of patentability. The sections relevant to plant

material and agriculture which are excluded from patentability are:

Section 3(h): a method of agriculture and horticulture.

Section 3(i): any process for medicinal, surgical, curative, prophylactic (diagnostic

therapeutic) or other treatment of human beings or any process for a similar treatment of

animals to render them free of disease or to increase their economic value or that of their

products.

Section 3(j): plants and animals in whole or any part thereof other than microorganisms but

including seeds, varieties and species and essentially biological processes for production or

propagation of plants and animals.

Section 3(p): an invention which in effect, is traditional knowledge or which is an aggregation

or duplication of known properties of traditionally known component or components.

Further the mere discovery of any new property or new use for a known substance or the

mere use of a known process, machine or apparatus unless such known process results in a new

product or employ at least one new reactant is not patentable. Also a patent claim for a substance

obtained by merely mixing ingredients resulting only in the aggregation of the properties of the

components is not a patentable invention. However, in India, method for rendering plants free of


- 52 -

diseases or to increase their economic value or that of their products can be claimed for patent

protection.

Microorganisms per se can be claimed for protection provided they are not mere discovery

of organisms. It is mandatory to deposit the biological material in International Depositary Authority

(IDA). In India, Institute of Microbial Technology (IMTECH), Chandigarh is a recognized

international depositary for some category of micro-organisms. If an applicant mentions a

biological material in the patent specification then disclosure requirements prescribed for biological

materials have been notified in the list of the Central Government or for indicating its source and

geographical origin [Section: 10,4(d)].

The purpose of a patent is to promote the progress of science and useful arts. The patent

law promotes this progress by giving the inventor the right of exclusion. In exchange for this right

to exclude others, the inventor must disclose all details describing the invention, so that when the

patent period expires, the public may have the opportunity to develop and profit from the use of

invention. A patent is enforced in the country which issues it, meaning thereby territorial in nature.

For each country a separate application is to be filed in that country where protection is sought.

Plant patents

Plant patents are obtainable in US and Japan. The US Plant Patent Act of 1930 (PPA)

granted property rights for privately developed plant varieties of asexually reproducing plants.

These rights were extended to new and distinct asexual varieties for a period of seventeen years.

Advances in breeding technology provided the momentum for the 1970 Plant Variety Protection

Act (PVPA). The PVPA provided protection for sexually reproducing plants, including seed

germination. In 1980 Diamond vs. Chakrabarty case set in motion the trend towards the legal

acceptance of the commodification of germplasm. Commodification is the process whereby an

object, whether tangible, such as seed, or intangible, such as knowledge about the seed, is turned

into a commodity, i.e. something that acquires an economic worth and can be bought and sold. US

Supreme Court in Diamond vs. Chakrabarty case decided that microorganism should not be

precluded from patentability for the objection raised by USPTO on the basis of “product of nature”.

The court held that a live, man made bacterium was patentable under the PPA and the ‘product of

nature’ objection therefore failed and the modified organisms were held patentable. In the Hibberd

case (1985), involving a tryptophan-overproducing mutant, the patent office ruled that plants could

be patented and there is no distinction between asexually and sexually propagated plants.

Following the principle established in the Chakrabarty case, it was decided that normal US utility

patents could be granted for other types of plant e.g. genetically modified plants. Plant patents

have been granted by European Patent Office (EPO) from 1989. But in 1995, EPO severely

restricted the scope of Plant Genetic Systems (Belgium) patent on herbicide resistant plants and

allowed claims only on the herbicide resistant gene and the process used in the generation of

plants. In Japan, plant patents are allowed, but there are some disputes over territorial rights. Life

forms of plants and animals except microorganisms are not patentable in India. In pursuance to


- 53 -

the TRIPS agreement, India has enacted “Protection of Plant Varieties and Farmers’ Rights”

(PPV&FR) Act, 2001, a sui generis system of plant variety protection which has been described in

detail separately.

Plant Variety Protection in India

As stated India is signatory to WTO agreements and it has to abide by the TRIPS

regulations. As per article 27.3(b) of the TRIPS which demand that member countries should

protect their plant varieties either by patent, or an effective system of sui generis protection, or a

combination of these two. In this context India chose a sui generis system for protection of plant

varieties. An Act named as Protection of Plant Varieties and Farmers’ Rights (PPV&FR) Act 2001

has been passed and Rules have been framed. PPV&FR Authority has been constituted with its

Head Office located at Delhi. The PPV&FR Act is TRIPS compliant and compatible with UPOV

system of plant variety protection (Anonymous, 2003).

The PPV&FR Act 2001 provides protection to following types of plant varieties

(Anonymous, 2003):

i. Newly bred varieties.

ii. Extant varieties – The varieties which were released under Indian Seeds Act, 1966 and

have not completed 15 years as on the date of application for their protection.

iii. Farmer’s varieties – The varieties which have been traditionally cultivated, including

landraces and their wild relatives which are in common knowledge, as well as those

evolved by farmers.

iv. Essentially derived varieties.

v. Transgenic varieties.

To qualify for registration under the act, a new variety has to conform to the criteria of

novelty (N), distinctiveness (D), uniformity (U) and stability (S). Besides, a denomination has to be

given for the registration of variety. Denomination refers to the label or title of the variety. It is the

denomination that is registered. For extant and farmers’ varieties which are in public domain the

DUS features will be considered while the novelty feature will not be taken because these varieties

are not new and are in public domain. In this act a special clause has been put which states that

any variety with terminator gene sequences will not be registered. Thus any transgenic material

with genetic use restriction technology (GURT) sequences will not be registered.

It is pertinent to note that the Act recognizes the farmer as a cultivator, conserver and

breeder. This embraces all farmers, landed or landless, male and female. Under the Sec. 2(k) of

PPV&FR Act, a farmers means any person who -i) cultivates crops by cultivating the land himself;

or ii) cultivates crops by directly supervising the cultivation of land through any other person; or iii)

conserves and preserves, severally or jointly, with any person any wild species or traditional

varieties, or adds value to such wild species or traditional varieties through selection and

identification of their useful properties. While the farmers’ variety under Sec. 2(l) means a variety


- 54 -

which- i) has been traditionally cultivated and evolved by the farmers in their fields; or ii) is a wild

relative or land race of a variety about which the farmers posses the common knowledge.

An application for registration can be made by any person claiming to be the breeder of the

variety, successor of the breeder, assignee, any farmer or group of community of farmers, any

person authorized for the above mentioned categories or any University or publicly funded

agricultural institution claiming to be the breeder of the variety. However, an application of farmer

variety filed by any farmer or group of farmers or community of farmers has to be endorsed by any

one of officers viz. District Agricultural Officer, District Tribal Development Officer, Director

Research of the concerned state Agricultural University, Chairperson/Secretary of the concerned

Panchayat Biodiversity Management Committee.

All the varieties will be registered with PPV&FR Authority. DUS guidelines for 35 crops

have been prepared by ICAR while guidelines for 12 crop species have been notified by PPV&FR

Authority in the gazette. PPV&FR Authority has established testing centres for each and every

crop species. In the first phase which has started in May, 2007, the registration of varieties will be

done for 12 crop species of cereals and legumes. The registration will then extend to 35 crops

which includes cereals, pulses, oilseeds, vegetable and two flower species. DUS guidelines are

also being prepared for medicinal and aromatic plants, spices, ornamentals and forest trees for

which task forces have been constituted by the PPV&FR Authority.

Indian PPV&FR Act allows farmers to save, use, sow, resow, exchange, share or sell his

farm produce including seed of a variety protected under this Act, but it prohibits that the farmer

shall not be entitled to sell branded seed of a variety protected under the Act [Sec. 39, 1(iv)]. The

farmers have been given the right to register farmers varieties themselves [Sec. 39,1(i)], right to

claim compensation for under performance of a protected variety from the promised level [Sec.

39(2)], benefit sharing for use of biodiversity conserved by farming community [Sec. 41]. According

to the concept of benefit sharing, whenever a variety submitted for protection is bred with the

possible use of a landrace, extant variety or farmer’s variety, a claim can be referred either on

behalf of the local community or institution for a share of the royalty [Sec. 41(1)] (Anonymous,

2003). In the Act a provision of compulsory license has also been put. According to this, after the

expiry of three years from the date of issue of certificate of registration of a variety, any person

interested can claim in an application to the authority alleging that reasonable requirements of the

public for seeds or other propagating material have not been satisfied or that the seed or other

propagating material is not available to the public at a reasonable price and pray for the grant of a

compulsory license to undertake production, distribution and sale of the seed or other propagating

material of that variety [Sec. 47(1)] (Anonymous, 2003).

The Act had laid down the norms for registration of plant varieties, fee structure, provisions

of opposition, DUS testing of material, etc. If any farmer or association of farmers is applying for

registration of a plant variety then this category is not required to pay any fee for either registration

or DUS testing. However, for the registration of farmer variety a farmer has to pay the fee for


- 55 -

application form. Also an affidavit for Rs 100/- on non judicial stamp paper has to be submitted

with the application form indicating that the variety does not contain any GURT or terminator gene

technology. For the registration of farmers’ varieties, farmers have to be motivated for filing of

application form or the SAU’s / ICAR institutes have to take the lead so that valuable germplasm

can be protected. In this direction Intellectual Property Management Centre of G.B. Pant University

of Agric. & Tech., Pantnagar has taken the lead by filing three applications of farmers’ varieties of

rice namely Tilakchandan, Hansraj and Indrasan on behalf of the farmers and for the benefit of

farmers. PPV&FR Authority has gazette notified that extant varieties which includes farmer’s

varieties will be registered in the next 3 years from the date of notification of registration of

varieties for 12 crop species. Thus there is an urgency to register the farmers varieties otherwise

the valuable germplasm which was being conserved by the farmers will remain unprotected and

any body can utilize for pecuniary gains.

Once the variety has been tested for its features then the Registrar of the Authority will

issue the certificate of registration. It shall have the validity of nine years initially in case of trees

and vines with renewal up to a period of 18 years. For other crops certificate of registration will be

issued for six years initially with renewal up to 15 years. In case of extant varieties the validity

period is 15 years from the date of notification of that variety by the Central Government under

section 5 of the Seeds Act 1966.

REFERENCES

1. Anonymous, 2003. The Protection of Plant Varieties and Farmers’ Rights Act, 2001 and Rules, Universal Law Publishing Co., Delhi, 2003.

2. Chawla, H.S., 2007a. Managing intellectual property rights for better transfer and commercialization of agricultural technologies. J Intellectual Property Rights, 12: 330 – 340

3. Chawla, H.S., 2007b. Intellectual Property Rights. J. Eco-friendly Agriculture, 2(2): 103-112

4. Chawla, H.S. and Singh, A.K., 2005. Intellectual Property Rights. Vol II: Copyrights, Trade Marks, Trade Secrets and Geographical Indications. Pantnagar University Press, pp-75

5. Chawla, H.S. and Singh, A.K., 2007. Intellectual Property Rights: Patents, Plant Variety Protection and Biodiversity, Published by Intellectual Property Management Centre, G.B. Pant Univ. of Agric & Tech., Pantnagar, 54 p.


- 56 -

Contribution of Uttaranchal Seeds & TDC in the Prosperity of the Farmers

H.K. Singh

Uttaranchal Seeds and Tarai Development Corporation, Haldi-263 146 (Uttarakhand)

Uttaranchal Seed & Tarai Development Corporation is the first state seed corporation in the

country. It was established in the year 1969 as a Seed Production arm of Pantnagar University

under the chairmanship of the then Vice-Chancellor Dr. Dhyan Pal Singh in the University. It was

restructure in the year 1978 as the U.P. Seeds & Tarai Development Corporation has strived hard

to provide farmers best quality seed under the brand name “Pantnagar Seed”. Pantnagar seed is

known for it superior quality every where. Corporation has also contributed immensely in the

prosperity of farmers all over the country.

It was first of its kind PPP (Public Private Partnership) model in the field of Agriculture

where farmers have biggest share in the production, processing, Marketing and the highest level

of decision making. Corporation has played a important role in bringing up green revolution in the

country. Corporation has strong focus on quality control of the seed made available to the farmers.


- 57 -

Quality Control Arrangements in the Seed Production

Deepak Pande Uttaranchal Seeds and Tarai Development Corporation, Haldi-263 146 (Uttarakhand)

The Uttaranchal Seeds & Tarai Development Corporation, Limited (UAS&TDC) was

established on 29th June 1996 as “Tarai Development Corporation Limited” and has pioneered for

bringing the first Green Revolution of the country with help of G.B. Pant University of Agriculture &

Technology, Pantnagar and farmers of Tarai Region of erstwhile Uttar Pradesh. The Corporation

has been producing, processing and marketing high quality seeds high yielding varieties of

cereals, pulses, oilseeds, vegetables and fodder with the popular brad equity of “PANTNAGAR

SEEDS” WHICH HAS BEEN ACCEPTED BY THE FARMING COMMUNITY OF THE COUNTRY WIDELY.

After launching the National Seeds Project by the Government of India, our Corporation has also

been re-started functioning in the name and style of “U.P. Seeds & Tarai Development Corporation

Limited” and has become the Mother Project for establishment of other State Seeds Corporation in

the country. The active participation of the Corporation for economic growth of the farming

community of the country has been widely appreciated and the Corporation has been conferred

with many National Productivity Awards by the National Productivity Council of Government of

India.

Consequent upon the creation of the new state of Uttarakhand, this Corporation has also

been on 9th December 2002 and renamed as Uttarakhand Seeds & TDC. Prior to that we were

producing around 12,00,000 quintals of certified Seeds of various crops/varieties of cereals,

pulses, oilseeds, vegetable and fodder per year. Still now more than 3500 farmers belonging to

Uttarakhand and Uttar Pradesh are closely associated with us as our shareholders but the

production target has considerably, educed as we are not getting the state and central level

benefits of production incentive and distribution subsidy for interstate marketing. Considering the

geological condition, size of the state and limited area under cultivation the requirement of seeds

in Uttarakhand is limited whereas the state enjoys the privilege of having both temperate and

tropical climatic conditions and the major portion of the seeds produced is being distributed in Uttar

Pradesh, Bihar, West Bengal, Assam, Orissa, Himachal Pradesh etc.

Under National Food Security Mission Government of India has identified some states

which includes Uttar Pradesh & Bihar and has been allowing distribution subsidy on wheat @ Rs.

500/- per quintal and Rs. 1200/- per quintal in case of pulses and oilseeds. In addition to this

concerned state seeds corporation, National Seeds Corporation is also enjoying this facility on the

seeds sold by them all over the country. But our Corporation is deprived resulting which cost of our

seeds becomes costlier by Rs. 500/- and Rs. 1,200/- per quintal respectively which has adversely

affected our sale in these states whereas these are our potential marketing zone.

Since its inception, corporation has been contributing immensely towards increasing the

National Agricultural Productivity by supplying more than 3 lac quintals of quality seeds to different


- 58 -

states. Major one is U.P. and this naked fact is always ignored by the nodal agencies for

formulating and implementing various central sector schemes. It is not our of place to mention

here that we have all the capabilities for producing and distributing at least 25% of the total

requirement of seeds in the country if it is also recognized as a nodal agency as in the case of

National Seeds Corporation etc. The aim of “National Food Security Mission” can only be achieved

if the Seed Replacement Rate is increased from the present ratio to relevant lands, over the years

to come as the availability of cultivable land is decreasing while the population is increasing.

Under the circumstances it has become essential to make available high quality, high

yielding and disease resistant seeds to the farmers in adequate quantity both for economic growth

of the farmers and achieving the aims of the Government of India Forits “National Food Security

Mission” to ensure the food security for its citizens.


- 59 -

Role of GBPUA & T in Agricultural Development and Popularization of Seeds of New Varieties

S.C. Mani

Department of Genetics and Plant Breeding, G.B.P.U.A.&T., Pantnagar-263145 (Uttarakhand) G.B. Pant University of Agriculture and Technology, Pantnagar has been pioneer in

imparting education in agriculture and allied sciences and technology, conducting need based

research and transfer of technology. The research programmes are designed towards socio-

economic upliftment of rural people through enhanced agricultural production and supply of quality

seeds of improved varieties of field and vegetable crops and planting material of fruit crops,

aromatic and medicinal plants, ornamental plants, agroforestry trees, mushroom and fish seeds.

The university has a pride place of evolving 205 improved varieties of various crops viz. wheat

(21), rice (16), maize (13), pulses (30), soybean (18), oilseeds (7), forage crops (18), sugarcane

(8), millets (10), cotton (3), dhaincha (1), buckwheat (2), poplar (1), pear (3), mango (1), guava (1),

jackfruit (2), aonla (1), papaya (2), bael (1), citrus (1), karonda (3), peach (1), plum (2), chilli (1),

brinjal (4), tomato (2), cauliflower (4), French bean (2), garden pea (4), coriander (1), bitter gourd

(2), ridge gourd (1), bottle gourd (3), cucumber (3), long melon (1), garlic (1), turmeric (1), fennel

(1), fenugreek (1), black cumin (1), ajowain (1), and gladiolus (1). Various categories of seeds of

these varieties are regularly produced at various research units of the university as per demand of

the State Government Govt. Of India, State Seed Corporations and private seed companies.

Some seed of the new varieties is directly sold to the farmers for quick spread and adoption of new

technologies. Besides, the production of good quality seed, various other technologies related to

enhanced agricultural productivity viz. crop production and management soil health management,

post harvest management and value addition to agricultural produce.

Current Status of Seed and Planting Material Production in the University

Nucleus Seed

Maintenance of the genetic purity of different varieties is the responsibility of the concerned

breeder and the concerned institute. Nucleus seed is the base of the seed production programme

and the purity of advanced generation seeds (breeder, foundation and certified seed) depends

upon the purity of the nucleus seed. The purity of the nucleus seed is maintained by undertaking

nucleus seed programmes appropriate for seed and vegetatively propagated crops.

Breeder Seed

Breeder seed is the next most important category in the seed production chain. It is 100

per cent pure and is produced under the direct supervision of the breeder at the Research Stations

and University Farm. The volume of the seed and the choice of the variety to be produced

depends upon the popularity of the variety and the indent received from the Department of

Agriculture and Cooperation, Ministry of Agriculture, Government of India. The purity of the

breeder seed is monitored by the committee constituted by Government of India. Every year the


- 60 -

university produces about 65,000-75,000 quintals of breeder seed at the Breeder Seed Production

Centre, Crop Research Centre, University Farm, Vegetable Research Centre, Sugarcane

Research Centre, Kashipur and Hill Campus, Ranichauri.

Foundation Seed

Foundation seed comes next after the breeder seed and its availability is essential for the

production of certified seed. Foundation seed production also requires proper care and supervision

from time to time. Foundation seeds are produced at the Crop Research Centre, University Farm,

Medicinal Plant Research & Development Centre, Hill Campus Ranichauri and Agriculture

Research Station, Majhera.

Certified Seed

Certified seed is the ultimate product which is sold to the farmers for cultivation. certified

seed production also requires good care and inspection from time to time. Its quality depends

upon the purity of the crop and post harvest processing. The certified seed in the university is

produced at several centers namely, Crop Research Centre, Vegetable Research Centre,

University Farm, Medicinal Plant Research and Development Centre, Agro Forestry Research

Centre, Model Floriculture Centre, Hill Campus, Ranichauri, Agriculture Research Centre, Majhera

and V.C.S.G. College of Horticulture, Bharsar.

Future Thrust

Though the university produces a large quantity of seed of various categories in

coordination with UA Seeds & Tarai Seed Development Corporation, but still there is some

shortfall in the availability of certified seed of hill varieties of rice and wheat due to non-availability

of large government farms in the hills. Currently, the seeds of hill varieties are also produced at the

main campus of the University at Pantnagar. The vegetative phase of the hill varieties is of short

duration and result in quick flowering and early maturity. The time left for the growth and tillering is

very short. Therefore, the yields are low. Hence, seed production of the hill varieties has to be

taken in the hill regions. For this, the farmers also need to be convinced and trained in the seed

production work. Seed production of hill varieties is also undertaken at the research stations of the

university located in hills.

The minor millets like, finger millet, foxtail millet, jhingora and underutilized crops like, buck

wheat, rice bean and amaranth occupy a sizeable area in Uttarakhand hills and some high yielding

varieties have also been developed. Efforts are being made to produce requisite quantity of seed

of hill varieties so that the farmers benefit from their high yield and nutritive value.

The pulse crops like, gram, field pea, urd, moong, pigeon pea and lentil form the main

source of protein for the poor and under nourished people of the hills. The gram is grown in the

plains but the other pulses are grown in the plains as well as in the hills. The availability of certified

seed of new varieties is not up to the desired level because seed production of these crops

involves high risk. The prevailing price of the pulses in open market is also higher than rates fixed


- 61 -

by the Government for the breeder seed and the price paid by the seed industry to the producers.

The farmers have to be given some incentive for the seed production of pulses.

Vegetables, flowers and aromatic & medicinal plants also play an important role in the

overall economy of the state. The adoption of hybrid varieties of vegetables and flowers is very low

in the state due to non-availability of genuine hybrid seed of different crops. Moreover, the hybrid

seed is very costly for the common farmers of the state. The area under hybrid vegetables can be

increased if the farmers of the region are trained to produce the hybrid seed of the vegetable crops

of their region.

In view of the above and the fact that seed replacement rate has to be increased to 25 per

cent in self pollinated crops, 50 per cent in cross pollinated crops and 100 per cent in hybrids, the

seed production activities at all the centers needs to increased. The seventh SOC Meeting of

ICAR for the year 2007 held on 11th July, 2007 under the Chairmanship of Secretary (DARE) &

DG, ICAR has also observed that the seed production during the year 2007-08 be doubled as

compared to 2006-2007. This requires creation of new facilities and improvement in existing

facilities.


- 62 -

Soil Health and Quality Seed Production

B. Mishra Department of Soil Science, G.B.P.U.A.&T., Pantnagar-263145 (Uttarakhand)

Soil health may be viewed as the component of ecosystem health that reflects the

properties of soil as a living system. In simplest terms, soil health can be defined as "the fitness of

soil for use" (Doran et al. 1996). In agricultural systems, healthy soil provides for the sustained and

productive growth of crops with minimal impacts on the environment.

Soil is a component of primary importance in crop production, even if it is often neglected,

or only regarded as a physical support for the growth of plants. However, with the increasing

concerns for the sustainability of agriculture and environmental protection, soil must be considered

as a living system. Its quality results from the multiple interactions among physicochemical and

biological components, notably the microbial communities, primordial for soil function. Crops are

affected by soil health and threatened by soil-borne diseases.

The terms “soil health” and “soil quality” are often used synonymously. However, soil health

may be considered as the state of soil at a particular time with reference to benchmark soil,

whereas soil quality refers to its ability to function for a specific purpose. Two soils may be equally

“healthy” but may achieve different levels of plant productivity because of differences in their

inherent quality.

There are two components of soil quality viz. inherent and dynamic. Inherent soil quality

refers to the characteristics that define a soil’s inherent capacity for plant production. These are

usually static, changing little over short time frames (years to decades). Soil texture and soil

mineralogy are commonly included as properties of inherent soil quality for productivity. Other soil

properties such as total soil carbon, cation exchange capacity (CEC) and exchangeable sodium

percentage (ESP) may also be considered as inherent properties, even though they may be

altered by management over longer time frame.

Properties of dynamic soil quality are those that change in response to human use and

management normally over relatively short time frame (years to decades). Agricultural soils of high

quality or good health maintain high nutrient availability, permit adequate infiltration of water and

air, have relatively stable structure and maintain a functionally diverse community of soil

organisms that support a relatively high level of plant productivity. These processes are reflected

in specific physical, chemical and biological properties of soils.

It is not feasible to measure all soil properties in order to assess the soil quality or health.

Some indicators are needed to facilitate the measurement of soil quality. These indicators cover

the whole range of soil physical, chemical and biological properties, reflect soil functions, and are

easy to measure for a variety of users and under various field conditions, and respond to changes

in climate and management. Table 1 lists a set of indicators that are commonly used to

characterize soil quality or soil health. Key indicators are soil texture, bulk density, aggregation,


- 63 -

available water capacity, pH, EC, NPK reserves, organic C, and microbial biomass. In specific

situations, additional soil properties may be identified as indicators e.g. soil aggregation, ESP,

micronutrient status, pesticide residues and heavy metal pollutants.

Table 1: Some soil physical, chemical and biological properties used as indicators

of soil health

Soil property Information

Physical properties

Soil texture Retention and transport of water, nutrients and chemicals, susceptibility to erosion; stabilization of organic matter and soil structure

Topsoil and rooting depth Water and nutrient availability, rooting volume for crop production

Soil bulk density Volume of pore space, compaction

Infiltration, hydraulic conductivity

Runoff and leaching potential, drainage

Water content Available water

Water holding capacity, water release curve

Availability of air and water, retention and transport of water and chemicals, drainage

Chemical properties

pH Acidity or alkalinity of soil, nutrient availability

Electrical conductivity Presence and quantity of soluble salts

Available N, P, K Plant available nutrients

Organic C and N Organic matter reserves, nutrient cycling, soil structure

Biological properties

Potentially mineralizable N Potential to supply plant available N

Microbial biomass Size of microbial population, pool of rapidly cycling organic matter and nutrients

Soil respiration Availability of soil organic matter reserves, microbiological activity

Soil productivity can certainly be lost through erosion, nutrient mining or other processes

such as salinization, sodification, compaction and water logging. The linkage between soil

productivity and soil health or quality is apparent when changes in soil attributes used to assess

soil quality are linked to causes of productivity loss. The effects of management practices on

productivity can also be assessed using soil quality attributes.

Building or restoring soil health or quality may involve a range of measures adopted at the

field, farm or watershed level, to optimize resource conservation. Integrative approaches to land

use, such as conservation tillage and organic farming have shown that management inputs (e.g.

crop residues) and system diversity (e.g. crop rotation) strongly influence dynamic soil properties.

Recently, favorable effects of integrated nutrient management on soil quality indicators have been

reported (Sharma et al. 2005).

Agricultural practices that affect soil health/quality

1) Soil conservation

2) Tillage

3) Addition of organic matter (manures, crop residues)

4) Use fertilizers and agrochemicals


- 64 -

5) Cropping system

6) Irrigation

Components of soil health/ quality management

The seven components of soil quality management are discussed briefly below: Choosing

specific practices within each component depends on the situation since different types of soil

respond differently to the same practice. Each combination of soil type and land use calls for a

different set of practices to enhance soil quality.

1. Enhance organic matter content: Whether the soil is naturally high or low in organic matter,

adding new organic matter in the form of compost, crop residues etc every year is perhaps the

most important way to improve and maintain soil quality. Regular additions of organic matter

improve soil structure, enhance water and nutrient holding capacity, protect soil from erosion

and compaction, and support a healthy community of soil organisms. Practices that increase

organic matter include: leaving crop residues in the field, choosing crop rotations that include

high residue plants, using optimal nutrient and water management practices to grow healthy

plants with large amounts of roots and residue, growing cover crops, applying manure or

compost, using low or no tillage systems, and mulching.

2. Avoid excessive tillage: Tillage is used to loosen surface soil, prepare the seedbed, and

control weeds and pests. But tillage can also break up soil structure, speed up the

decomposition and loss of organic matter, increase the threat of erosion, destroy the habitat of

helpful organisms, and cause compaction. New equipment allows crop production with minimal

disturbance of the soil.

3. Manage pests and nutrients efficiently: An important function of soil is to buffer and detoxify

chemicals, but soil's capacity for detoxification is limited. Pesticides and chemical fertilizers

have valuable benefits, but they also can harm non-target organisms and pollute water and air

if they are mismanaged. Nutrients from organic sources also can pollute when misapplied or

over-applied. Efficient pest and nutrient management means testing and monitoring soil and

pests; applying only the necessary chemicals, at the right time and place to get the job done;

and taking advantage of non-chemical approaches to pest and nutrient management such as

crop rotations, cover crops, and manure management.

4. Prevent soil compaction: Compaction reduces the amount of air, water, and space available

to roots and soil organisms. Compaction is caused by repeated traffic, heavy traffic, or

traveling on wet soil (such as puddling for rice transplanting). Deep compaction by heavy

equipment is difficult or impossible to remedy, so prevention is essential.

5. Keep the ground covered: Bare soil is susceptible to wind and water erosion, and to drying

and crusting. Ground cover protects soil, provides habitats for larger soil organisms, such as

insects and earthworms, and can improve water availability. Ground can be covered by leaving

crop residue on the surface or by planting cover crops. In addition to ground cover, living cover

crops provide additional organic matter, and continuous cover and food for soil organisms.

Ground cover must be managed to prevent problems with delayed soil warming in spring,

diseases, and excessive build-up of phosphorus at the surface.


- 65 -

6. Diversify cropping systems: Diversity is beneficial for several reasons. Each plant contributes

a unique root structure and type of residue to the soil. A diversity of soil organisms can help

control pest populations, and a diversity of cultural practices can reduce weed and disease

pressures. Diversity across the landscape can be increased by using buffer strips, small fields,

or contour strip cropping. Diversity over time can be increased by using long crop rotations.

7. Manage irrigation: Use of excessive amounts of water for irrigation is not only wasteful but

also harmful. Excess water may cause water logging if proper drainage system is not in place.

Excessive withdrawal of ground water for irrigation lowers the ground water level. If the

irrigation water quality is brackish, soil salinity builds up which lowers the soil productivity.

Soil factors that influence seed quality

S. No.

Soil factors Seed quality parameters that are affected

1 Acidity, alkalinity, Grain size, bldness, uniformity, viability, disease incidence

2 Salinity Grain size, boldness, uniformity, viability

3 Nutrient supply Grain size, boldness, uniformity, viability, disease incidence

4 Organic matter Grain size, boldness, uniformity, viability, disease incidence

5 Soil aggregation Grain size, uniformity

6 Moisture availability Grain size, boldness, uniformity, viability

7 Aeration (water logging) Grain size, boldness, uniformity, viability

8 Compaction Grain size, boldness, uniformity, viability

9 Soil microbes Disease incidence, viability, uniformity

10 Bioinoculation (N2 fixers, Biocontrol microorganisms)

Grain size, viability, uniformity, disease incidence

Disease Suppressive Soils

Plant diseases are caused mainly by fungi, bacteria, viruses and nematodes. Soil biota

contain a number of these pathogens, beside a large number of beneficial organisms. The

phenomenon of disease suppressive soils has fascinated plant pathologists for decades.

Suppressive soils are those in which a specific pathogen does not persist despite favorable

environmental conditions or the pathogen establishes but doesn't cause disease, or disease

occurs but diminishes with continuous monoculture of the same crop species. The phenomenon is

believed to be biological in nature because fumigation or heat-sterilization of the soil eliminates the

suppressive effect, and disease is severe if the pathogen is re-introduced.

Potato scab, a soil-borne disease, is much more severe in alkaline soils. It can be

prevented by the use of fertilizers and soil treatments that bring pH so low that the scab organism

cannot grow. The reverse is true of wilt and club root diseases of cabbage, which is made worse

by acid soil; the use of alkaline materials helps control these diseases.

REFERENCES

1. Doran, J.W., Sarrantonio, M and Liebig, M.A. (1996) Soil Health and Sustainability. Advances in Agronomy 56, 1-54.

2. Sharma, K.L., Mandal, U.K., Srinivas, K., Vittal, K.P.R., Mandal, B., Grace, J.K. and Ramesh, V. (2005) Long-term soil managmenet effects on crop yields and soil quality in a dryland Alfisol. Soil & Tillage Research 83, 246-259.


- 66 -

Agronomic Management of Seed Quality

R.S. Verma Department of Agronomy, G.B.P.U.A.&T., Pantnagar-263145 (Uttarakhand)

The quality of the produce has become more important at present in view of consumer

awareness and competition in the world market. The quality of the crop produced depends mainly

on the quality of the seed sown. The seed quality encompasses several parameters including

purity (both genetic and physical purity), germinability and health. Use of assured quality seed

ensures the product to be true to the type and of good quality. Presence of seeds of other

variety/species and diseased seeds reduces the quality of the product and also its productivity.

The product of seed purity and germination percentage determines “pure live seed” content of the

lot which is the basis for determining seed rate for a crop. The seed produced should meet a

minimum level of seed quality as prescribed in Indian Minimum Seed Certification Standards.

There are several factors which determine seed quality.

Influence of location

The location influences seed quality and its productivity by determining micro-climate

available to the crop which is determined by the soil and atmospheric conditions prevailing at

different locations of seed production. Therefore, it is important to know the influence of soil and

atmospheric conditions on the quality of seed produced.

A. Soil: The soil physical and chemical composition determines suitability for a crop. Only those

crops which can be successfully grown on a particular soil for grain production will also be suitable

for seed production. The soils incapable of realizing potential of genotype will certainly produce

low quality seed. Careful selection of the land can prevent many problems and minimize work of

rouging. The field selected should be free from prohibited noxious weeds, relatively free of other

weeds and volunteer plants. The land to be used for seed production should be free from soil

borne diseases and insects infesting the crop.

B. Atmosphere: The atmospheric changes associated with site of seed production influence

both productivity and quality of seed. These include temperature and rainfall/humidity which

influence insect, pest and disease of the crop. Light available at a particular location also influence

seed quality.

a. Temperature: Temperature plays an important role in quality seed production. Temperature

prevailing during vegetative growth of crop would mainly influence the productivity but temperature

experienced by the crop during seed filling will greatly influence seed quality. The temperature

should be moderate at the time of seed development. Too high temperature or frost during seed

maturation is detrimental to seed quality. Tripathi (2003) observed significant reduction in seed

index due to one month delay in wheat sowing due mainly to rise in temperature during

reproductive phase. This resulted in significant reduction of seedling vigour parameters viz. root

length, root dry weight, shoot dry weight and seedling vigour index. Contrary to this in Kharif


- 67 -

season, early planting result into seed maturity when temperatures are high and chances of rainfall

are also there. The seed produced from such crop are though bold in size but poor in seed quality.

It was found at Pantnagar by Gupta et. al. 1973 that soybean crop planted in June gave seeds of

poor quality than the crop planted in July or early August.

Some crops like winter rye (Scale cereale) cabbage, beet, celery have vernalization requirement.

If this requirement is not met, the crop may not produce seed .Whereas freezing temperature can

cause freeze injury in several other crops like maize. Temperature also influences seed dormancy.

b. Rainfall/humidity: Rainfall and humidity are inter related. Rainfall increase relative humidity of

the atmosphere which may be harmful. High humidity in association with high temperature is

conducive for incidence of disease and insects. Moderate to low relative humidity is required for

seed filling. Rainfall before the harvest of seed crop increases relative humidity in seed

environment which adversely affects seed quality.

Alternate wetting and drying caused by rainfall results into seed coat rupturing and reduced

storability in large seeded legumes like soybean. Similarly, occurrence of rainfall after maturity of

cereal crops like wheat, maize etc. which do not have seed dormancy, results into pre-sprouting of

seed and spoilage of seed on mother plant itself. Such seeds loose their germinability. Rain after

harvestable maturity of wheat decreases bulk density due to roughing of seed coat. The texture of

seed becomes rough. In addition to this, untimely rain may also adversely influence seed set

especially in cross pollinated crops.

c. Light and Photoperiod: The effect of light available to mother plant is related to the quality of

seed produced .Light availability during vegetative growth phase of the crop influences crop

growth. The duration of light available during vegetative phase will also influence the seed quality

by determining the time of flowering as most of the crop plants are photo-sensation. Light available

during reproductive phase will influence seed filling through assimilate supply by the process of

photosynthesis. Photoperiod available during seed development is also known to have its effect on

seed dormancy of some crops.

Agronomic Management

Agronomic practices for crop production change with the location. Site specific cultural

practices should also be adopted for seed multiplication with emphasis on isolation, weeding and

rouging to meet the certification standards. Agronomic practices in relation to seed quality are

discussed below:

1. Selection of crop and variety: The crop selected for seed multiplication should be such that

it can produce good quality seed at the given location. The grain crops grown in the locality

can also be grown for seed production. However, varieties susceptible to insects and diseases

of the area should not be grown for seed multiplication.

2. Time of sowing: Sowing time recommended for the specific crop for the specific location for

commercial crop production is good for production of seed as well. Early or late sowing of crop

may adversely affect the seed quality and its productivity.


- 68 -

3. Isolation: The seed production plot must be isolated from various sources of contamination by

a certain minimum distance known as isolation distance. Isolation is more important in cross-

pollinated crops to avoid genetic contamination through cross-pollination whereas in a strictly

self pollinated crop, it is mainly to avoid mechanical mixture from adjoining fields. Isolation

requirement varies from 3 metres in self pollinated crops like wheat and paddy to hundreds of

metres in cross-pollinated crops (1600m in case of cabbage, cauliflower etc.).

4. Seed rate/row spacing: Planting density may influence quality of produce due to completion

between plants for resources like nutrients, water, light etc. Limited literature available does not

indicate significant differences in seed quality probably because of compensatory mechanism

of crop plants.

5. Method of sowing: The seed crop must be sown in lines. It should be sown in such a way that

it facilitates movement of personnel for effective roguing. This can be achieved by skipping are

row after every eight to ten row in wheat seed crop. Paired row planting can be adapted in

case of paddy, green gram and chickpea. The seed drill (cups, pipes and box) must be cleaned

before and after sowing of one variety.

In hybrid seed production, male and female parents must be planted in the recommended

ratio. The row direction is very important in wind pollinated crops and it should be kept nearly

perpendicular to the prevalent wind direction at the time of flowering.

6. Mineral nutrition: Application of nutrients especially in soils which are deficient in one or more

elements may affect seed quality parameters. Nitrogen application increases seed protein content

which influences seed quality probably by influencing enzymes as all enzymes are proteins. Lowe

and Ries (1973) found an increase in seed protein content with increase in nitrogen application.

More than 86% of seed protein was found in endosperm of wheat seed. Nandisha and

Mahadevappan (1984) found increase in seed vigour parameters with increases in NPK level and

attributed it to increase in seed size and seed protein content.

7. Irrigation: Irrigation is related to supply of soil moisture. Soil moisture stress at critical growth

stages will adversely affect the seed set and seed filling. For most of the crops flowering is most

critical stage. Withdrawal of irrigation during flower bud initiation stage will adversely affect the

number of seeds to be formed. Similarly, moisture stress during grain filling stage will reduce seed

size which will have low vigour. In case of rice, panicle emergence has been found to be most

critical stage. If drought occurs at this stage, whole inflorescence will become sterile.

8. Weed management: Weed control is an important aspect of seed production. Weeds present in

crop not only compete with crop plants for resources but also affect seed quality by reducing the

size of seeds and yield. Presence of weed seeds especially those which are inseparable from crop

seed may lead to rejection of the seed lot. The seed lot must meet minimum seed certification

standards. The total number of weed seeds present in the field/seed sample should not exceed the

limit which is zero in some cases. Similar is the case with diseased seeds. Therefore, due care

should be taken for control of diseases especially those in which seed is carrier of pathogen.


- 69 -

9. Roguing: Roguing may be defined as careful and systematic evaluation of a seed production field

and removal of all undesirable plants. A plant is classified as “rogue” if it is atypical. In other words,

any plant which does not conform to the varietal description is turned as rogue. The goal of this

operation is to ensure the desired varietal and physical purity in the seed production field.

Roguing should be conducted before genetic or physical contamination occurs and

during times favorable for visual identification. Visual differences in plant characteristics can be

made at post emergence, vegetative development, flowering, post flowering and pre-harvest

stages during crop life cycle.

10. Time of harvest: Seed has maximum viability and vigour at the time of physiological maturity. At

this stage seed moisture content is very high. For good quality seed, crop should be harvested at

the earliest once it has reached harvestable maturity. Leaving mature seed in field for long time will

adversely affect the seed quality due to diurnal changes in temperature and relative humidity.

11. Harvesting: After the seed field is approved for seed standards, seed crop can be harvested. To

minimize mechanical damage to the seed during harvesting, the crop should be harvested at safe

moisture content which is 15-17% for wheat, 17-20% for paddy, 13-15% for soybean and 25-30%

for maize.

In hybrid seed production, male parent lines should be harvested first and removed.

Female parent lines should be harvested after inspecting whole field to confirm that all the male

plants have been removed.

The thresher, combine, trailers, threshing floor etc. must be thoroughly cleaned in

between handling of different varieties to avoid mechanical admixture.

Conclusion: The quality of seed produced is influenced by the location of seed multiplication through

climatic condition prevailing at the location. Therefore, agronomic practices adopted for seed

production should be site specific keeping in mind the condition of soil and atmosphere of the location.

REFERENCES

1. Agrawal, P.K.; B.D. Agrawal; P. Venkat Rao and J. Singh 1998. Seed multiplication, conditioning and storage. In M.L. Morris (Ed.) Maize Seed Industry in Developing Countries. Lynne Rienmer Publishers and CYMMIT, Colorado, USA and Maxico.

2. Gupta, P.C.; D.A. Miller and C.N. Hittle 1973. Soybean seed quality as influenced by variety and planting date grown at two locations in India. Seed Res. 1:67-74.

3. Lowe, L.B. and S.K. Ries 1973. Edosperm protein of wheat seed as a determinate of seedling growth. Plant Physiol. 51:57-60.

4. Nandisha, S.B. and M. Mahadevappa 1984. Influence of mother plant nutrietion and spacing on planting value of rice seeds (Oryza sativa L.). Seed Res. 12:25-32.

5. Rai, S.D.; Y.P. Joshi and H.S. Malik 1977. Effect of sowing dates and seed rates on the seed production and seed quality of berseem (Trifolium alexandrinum L.) variety Pusa Giant. Seed Res. 5:11-16.

6. Tripathi, Neeta 2003. Studies on physiological parameters in relation to heat tolerance in eight wheat varieties. Thesis M.Sc. Ag. (Agronomy) G.B.Pant University of Agriculture & Technology, Pantnagar.


- 70 -

Post-Entry Quarantine Facilities and Requirements

D.B. Parakh, V. Celia Chalam & R.K. Khetrapal Division of Plant Quarantine, NBPGR, New Delhi- 110 012

Definition: Post-entry quarantine (PEQ) mean growing of imported plants in confinement for a

specified period of time in a glass house, screen house, poly house or any other facility, or isolated

field or an off-shore island that is established in accordance with guidelines/standards and are duly

approved and certified by an inspection authority notified under Plant Quarantine (Regulation of

Import into India) Order, 2003 with Amendments.

PEQ facilities and requirements

1. Isolation field: An open area/field which is situated in an isolated place/or within a boundary

or surrounded by hedges/trees in such a way that the main crop(s) are grown at least 400

meters away.

2. Greenhouse/screen house/poly house: This facility should be built in accordance with the

guidelines and approved by the inspection authority notified under this order.

Greenhouse(s) can be fabricated with polycarbonate sheets using evapo-transpiration (ET)

cooling system with insect-proof stainless steel wire mush of 40-60 mesh per linear inch size

covering cool cell pad and fan area(s) within the greenhouse. Entry to greenhouse should be

through double doors so that only one door is opened at a time at the entry point to avoid free flow

of air currents in the greenhouse that might carry winged insects/vectors such as aphids,

whiteflies, leafhoppers, thrips and mites.

Greenhouse(s) can also be fabricated with special polythene sheets (for poly house)

manufactured for this purpose which are coated with ultra violet protectants. These sheets can be

used in single/double layers and air can be pumped in or out to maintain certain temperature

inside these poly house(s). Plythene sheets are attached to aluminium bars/pipes erected on

concrete structures. ET cooling system can be used to cool the temperatures inside poly house up

to 280C Celsius.

Greenhouse complex should have a ‘head house’ that consists of an area where soil

sterilization and pot filling takes place. Pots filled with sterilized soil mix with sand and farm yard

manure including pesticide treatment are transported to pot growing chambers having fixed or

movable tables. There should be a constant supply of electricity and water for running the

greenhouse complex besides backup or generators. Besides having these approved greenhouse/

poly house, the PEQ should have incinerator to burn the plant residues to maintain sanitation.

The grower shall maintain an inspection kit containing all requisite items to facilitate

nursery inspection and ensure proper plant protection and upkeep of nursery records. At the end

of final inspection, the inspection authority shall forward a copy of the report of post-entry

quarantine inspection duly signed by him to the Plant Protection Advisor under intimation to

Officer-in-charge of concerned plant quarantine station.


- 71 -

Testing of legumes in PEQ greenhouse at NBPGR

The legume seed material that requires one season PEQ can be grown in direct sown

grow-out greenhouse (as done at NBPGR)/screen house/poly house in a one meter row per

accession with 45-60 cm row to row distance. Each row can be stacked with pre-treated bamboo

support sticks and jute thread to support plants within the row. All plants in a row are observed

regularly for expression of any suspicious looking symptoms and recorded and the plant(s) with

symptoms if any, are uprooted and potted in isolation or are caged for further observations.

Virological testing methods are employed to test seedlings grown in PEQ greenhouse by testing

by ELISA/electron microscopy. Harvest from only virus-free plants in released to the indenters.

Post-entry Quarantine

Post-entry Quarantine as given in Chapter IV of the Plant Quarantine (Regulation of

Imports into India) order, 2003 (Amendment) is as follows:

1. Plants and seeds, which require post-entry quarantine as laid down in Schedule V and VI of

this order, shall be grown in post-entry quarantine facilities duly established by importer at

his cost, approved and certified by the Inspection Authority as per the guidelines prescribed

by the Plant Protection Adviser.

2. The period for which, and the conditions under which, the plants and seeds shall be grown in

such facilities shall be specified in the permit granted under clause 3.

3. Nothing contained in Sub-clause (1) shall apply to the import of tissue-cultured plants that

are certified virus-free as per Schedule-V and VI, but such plants, shall be subjected to

inspection at the point of entry to ensure that the phytosanitary requirements are met with.

4. Every application for certification of post-entry quarantine facilities shall be submitted to the

inspection authority in Form PQ 18. The inspection authority if satisfied after necessary

inspection and verification of facilities shall issue a certificate in Form PQ 19.

5. At the time of arrival of the consignment, the importer shall produce this certificate before the

Officer-in-charge of the Quarantine Station at the entry point along with an undertaking in

form PQ 20.

6. If the Officer-in-charge of the Quarantine Station, after inspection of the consignment is

satisfied, shall accord quarantine clearance with post-entry quarantine condition on the

production, by an importer, of a certificate from the inspection authority with the stipulation

that the plants shall be grown in such post-entry quarantine facility for the period specified in

the import permit.

7. After according quarantine clearance with post-entry quarantine conditions to the

consignments of plants and seeds requiring post-entry quarantine, the Officer-in-charge of

the Quarantine Station at the entry point shall inform the inspection authority, having

jurisdiction over the post-entry quarantine facility, of their arrival at the location where such

plants would be grown by the importer.

8. It shall be the responsibility of the importer or his agent-


- 72 -

a. To intimate the inspection authority in advance about the date of planting of the imported

plants or seeds.

b. Not to transfer or part with or dispose the consignment during the pendincy of post-entry

quarantine except in accordance with a written approval of inspection authority.

c. To permit the inspection authority complete access to the post-entry quarantine facility at

all times and abide by the instructions of such inspection authority.

d. To maintain an inspection kit containing all requisite items to facilitate nursery inspection

and ensure proper plant protection and upkeep of nursery records.

e. To extend necessary facilities to the inspection authority during his visit to the nursery

and arrange destruction of any part of whole of plant population when ordered by him in

the event of infection or infestation by a quarantine pest, in a manner specified by him.

9. The inspection authority of concerned area of jurisdiction or any officer authorized by the

Plant Protection Adviser in this behalf, in association with a team of experts shall inspect the

plants grown in the approved post-entry quarantine facility at such intervals as may be

considered necessary in accordance with the guidelines issued by the Plant Protection

Adviser, with a view to detect any pests and advise necessary phytosanitary measures to

contain the pest(s).

10. The inspection authority shall permit the release of plants from post-entry quarantine, if they

are found to be free from pests and diseases for the period specified in the permit for

importation.

11. Where the plants in the post-entry quarantine are found to be affected by pests and diseases

during the specified period the inspection authority shall:

a. Order the destruction of the affected consignment of whole or a part of the plant

population in the post-entry quarantine if the pest or disease is exotic, or

b. Advise the importer about the curative measures to be taken to the extent

necessary, if the pest or disease is not exotic and permit the release of the affected

population from the post-entry quarantine only after curative measures have been

observed to be successful. Otherwise, the plants shall be ordered to be destroyed.

12. Where destruction of any plant population is ordered by the inspection authority, the importer

shall destroy the same in the manner as may be directed by the inspection authority and

under his supervision.

13. At the end of final inspection, the inspection authority shall forward a copy of the report of

post-entry quarantine inspection duly signed by him to the Plant Protection Adviser under

intimation to officer-in-charge of concerned plant quarantine station.

14. The importer shall be liable to pay the prescribed fee for inspection of plants in the Post-

entry quarantine facility as laid down in Schedule-IX.

All efforts should be made to inspect imported planting material grown in PEQ as per the

guidelines of Plant Quarantine (Regulation of Imports into India) Order, 1003 with Amendments.


- 73 -

Efforts should be made to create standard facilities and requirements for PEQ growing and

clearance of imported planting material.

Some of the important planting material requiring Post-entry quarantine growing as per schedule V

& VI of P.Q. order 2003 (Amendment)

Sl. No.

Plant species/variety Post-entry quarantine period (special condition)

1. Banana (Musa spp.) 9-12 months

2. Cassava (Manihot esculenta) 1 year

3. Citrus spp. 1 year

4. Cocoa (Theobroma cacao) 1 year

5. Coconut (Cocos nucifera) & species 5 years/1reproductive cycle

6. Coffee (Coffea spp.) 1 year

7. Forest plant species (Elm, Oad, Pine etc.) 1 year

8. Grape vine (Vitus spp.) 1 year

9. Groundnut/legumes 6 weeks

10. Potato Two growth seasons

11. Rubber 1 year

12. Small temperate fruits (berries, ribes) 9-12 months

13. Sugarcane (Saccharum spp.) 1 year

14. Sweat potato One growth season

15. Tobacco One growth season

16. Temperate fruits (pome/stone/nut species) 1 year

17. Wheat One growth season

18. Yam One growth season

19. Ornamental plant (various) 3-6 months/1reprod. cycle


- 74 -

Resource Conservation Techniques in Seed Crop Health

K.P. Singh & Deepshikha Department of Plant Pathology, G.B.P.U.A.&T., Pantnagar-263145 (Uttarakhand)

Land and water, the two ultimate natural resources have been exploited indiscriminately to

meet need of human population. The advent of high yielding varieties as a result of green

revolution coupled with good management practices has further increased the depletion of these

resources. It has been found that an application of inadequate and unbalanced nutrient fertilization

to the crops not only results in low yields but also deteriorates the soil resources (Singh et, al,

1999 & Bisht et. al. 2006)

Continuous monoculture of cereals particularly rice and wheat has led to ecological imbalance

problems in soil hydrology and biotic environment. To overcome these problems, an ideal cropping

system which ensures a shallow-rooted crop followed by deep rooted one, fertility depleting by fertility

conserving/ restoring crop, soil degrading by soil regenerating crop and demanding heavy inputs by

those that thrive on low inputs, is the need of future to conserve our agricultural resources.

Modern crop production system is highly dependent upon heavy use of inputs i.e. machine,

fertilizers and agro-chemicals. The indiscriminate use of these inputs has resulted into fast increase in

environment pollution, high price of inputs and difficulty in sustaining the production level to feed the

alarming increase in human population. Hence to overcome these emerging problems there is urgent

need to work out an agricultural production system, which is eco-friendly, economically viable and

socially acceptable by adopting a judicious use of different inputs. Since agricultural development with

positive growth can not subsist on a deteriorating natural base, it is imperative to develop technology

for resource conservation.

Introduction

RCT has now evolved into something with far broader appeal including cost convenience,

profitability, food security and sustainability. This technology needs less investment through saving in

cost of cultivation and improves yield due to advance sowing or better efficiency of external inputs. Its

profit driven advantage has allowed small and medium farmers to gain confidence in this technology.

RCT’s are those practices which enhance resource/input use efficiencies. Zero-tillage,

permanent beds, minimum tillage, laser leveling etc. are components of RCT (RWC,

www.rwc.cgir.org).

Grover and Sharma (2007) observed zero-tillage system as the best practice providing benefit

cost ratio much higher (1.56) where as conventional agriculture accounted only 1.12 benefit cost ratios,

RCT’s are defined as any practice that will result in improvement of the efficiency of natural resources.

Resource Conservation Techniques Package

1. Laser land leveling 2. Zero/reduced tillage 3. Improved varieties 4. Seed treatment


- 75 -

5. Sowing time

6. Seed rate

7. Method of sowing

8. Nutrient management

9. Weed management

10. Intercropping

11. Plant protection measures

Laser Land Leveling: It helps in water and area saving upto 20-30% and 5% respectively, increase

in yield upto the extent of 15 to 20%. Uneven fields lead to poor germination and crop stands leadings

to lower yields and in yield excessive leaching of mobile nutrients (Gupta et. al., 2006)

Zero/reduced Tillage: In this system seed is placed into the soil by a seed drill without prior land

preparation. Where combine harvesting is becoming popular, loose straw and residue creates a

problem. Farmers presently burn residue to overcome this problem of loose stubble whether they

use zero-till or traditional system. Weed problem were lower under zero-tillage thus use of

herbicide is significantly lower. Early planting is the main reason for additional yields obtained

under zero-tillage. It helps in water saving (20-30%) energy saving (50%), decreasing pollution

and increasing the yield.

Reduced tillage can suppress pathogens because:-

• Relatively high soil microbial activity can lead to competition effects that may affect

pathogen activity and their survival and thus reduce harmful pathogen inoculum pressures

and suppress the severity of plant diseases.

• Microbial antagonism in the root zone leading to the formation of disease suppressive soils

can be beneficial for farmers.

• Creates conditions more favourable for the biological control of plant pathogens

• There are predatory organisms that will keep pest species such as nematodes and fungi in

check; protozoa engulf fungi and bacteria, while predatory nematodes eat root-feeding

nematodes.

• Beneficial fungi provide a physical barrier to root-feeding pests by wrapping the roots in a

network of threads (hyphae).

• Other soil organisms secrete chemicals that ‘hide’ plant roots from their attackers.

Improved Varieties: High yielding varieties recommended for specific area and conditions should be

chosen. Front line demonstrations on farmers field, showed 10-41% increase in yield of various rabi

pulses (where our country has become a cronic importer) by adopting improved variety over control.

Seed Treatment: It has been observed that seed treatment with fungicides minimize the incidence

of diseases like wilt, rot etc., and decrease plant mortality and increase the grain yield.

Time of Sowing: Time of sowing is an important aspect to take advantage of residual soil

moisture under rainfed conditions. Sowing time varies widely from place to place depending upon

cropping pattern followed.


- 76 -

Seed Rate: Adequate plant population makes high difference in yield. Sowing should be done with

recommended seed rate to give optimum plant population. Excessive seed rate or higher plant

population is unnecessary wastage of valuable resources and also cause more incidence of

insects pest and diseases.

Method of Sowing: Sowing should be done in line at proper spaced and depth.

Nutrient Management: Application of proper nutrient helps in increasing the yield and also saving

of fertilizer requirement, eg. Rhizobium inoculation of seeds increases grain yield of pulses by 10-

15% and leaves behind about 40 kg N/ha for succeeding crop. To activate the process of

nodulation, efficient Rhizobium strain should be used. Interaction between Rhizobium inoculation

and phosphorus application indicated a net saving of 20 kg P205/ha in lentil (Sahu et. al. 2007).

Weed Management: Weed compete with the crop plants for plant nutrient, space, water and light,

reduce the yield considerably. Application of weedicide, hand weeding at proper time found to

control the weeds & increase the yield.

Intercropping: It helps to minimize the incidence of insects pests and diseases, eg. chick

peas+wheat/barley/lin seed/mustard/ coriander; lentit+linseed/mustard/barley/sugarcane.

Advantage of Resource Conservation Technology

1. Reduced soil erosion by air, run off water and rainfall due to improved soil aggregation

properties and covering of soil by crop residues.

2. Enhances soil organic pool, water holding capacity and nutrient availability through gradual

decomposition of surface residues.

3. Improved soil bio-diversity.

4. Rescue surface soil, ground water and air pollution from improve use efficiency of

pesticide, weedicide and fertilizers.

5. Conserve non-renewable energy resource.

Resource Conservation Techniques in Rice

Rice is generally grown as a transplanted crop in puddle soil which reduces soil

permeability and create aquatics anaerobic conditions suited to control weeds, improves water and

nutrient availability. However, puddling destroys soil structure to form a compacted layer that

reduces infiltration and recharge of aquifer.

Table: Effect of puddling on rice yield at different locations

Puddle (Mt ha-1) Non-puddle (Mt ha-1) Soil texture Location

5.6 5.6 Clay loam IRRI Philippines

5.5 5.5 Clay IRRI Philippines

5.4 5.1 Vertisol Kenya

3.9 3.8 Clay Surinam

2.5 2.5 Sandy loam Senegal

5.9 5.5 Sandy loam Nigeria

5.0 4.8 Sandy loam Nigeria

5.9 5.7 Sandy loam Punjab, India

* Rice grain yields in puddled and non-puddled soil do not differ significantly (P=0.05)

Source-Ladha et. al. 2003


- 77 -

Zero till/Reduced-till in unpuddled Transplanted Rice: Zero or reduced tillage technique in

transplanted rice can replace the conventional puddle transplanted rice. Unpuddled soil do not

crack resulting in irrigation water economy compared to puddle rice. Due to less disturbance in

unpuddled soil, the weed pressure is low which ultimately influence the crop productivity. Trial

conducted in Western U.P. and Haryana have revealed that the water use and water productivity

under unpuddled and puddle transplanted rice were same, however the net return was higher in

unpuddled rice.

Table: Comparative performance of puddle & unpuddled transplanted rice

Crop establishment method

No. of trials Water (m3 ha)

Water productivity (kg grain/m3)

Net return (Rs./ha)

Western U.P.

Unpuddled TPR 61 8500 0.64 12,700

Puddled TPR 61 9000 0.62 11,760

Haryana

Unpuddled TPR 20 16176 0.42 21,358

Puddled TPR 20 15500 0.43 17,207

Source: USAID Project Report, 2004

Effect of tillage systems on incidence of diseases

Comparative incidence of diseases in zero and conventional tillage conditions in rice during

2000-02

During 2000, it was observed that the bacterial leaf blight incidence was significantly higher

in zero tillage plot as compared to conventional tillage, while during 2002, it was significantly lower

in zero tillage plot as compared to conventional tillage plot. On an average the incidence of both

the diseases (bacterial leaf blight, sheath blight) was significantly less in conventional tillage plot

as compared to zero tillage plot. The reason of higher incidence of diseases in zero tillage plot was

apparently due to presence of rice stubbles and crop residue in field that helps create favourable

micro-climate for pathogens.

Table Incidence of diseases in zero (ZT) and conventional tillage (CT) conditions in rice during 2000-02

Year

BLB (infected leaves per 10 hills)

SHB (no. of infected tillers per 10 hills)

ZT CT Mean ZT CT Mean

2000 2.96 2.78 2.87 0.24 0.41 0.32

2001 1.83 1.07 1.45 0.00 0.00 0.00

2002 0.99 0.70 0.84 0.45 0.21 0.33

Mean 1.92 1.52 - 0.23 0.20 -

(Singh, 2004)

Wet Seeding: Wet seeding involves sowing of pre-germinated seed, either broadcasted or drilled

into, puddle wet soil and then gradually flooding the field. Thus it also reduces the cost involved in

nursery raising and transplanting of seedlings. [email protected] kg a.i. ha-1 in 500-600 litre water

should be applied in the field when rice seedlings are 2-3 leaf stage for effective management of

weeds. Studies conducted in Pantnagar revealed that wet seeded rice generally recorded higher

grain yield in weed free situation as compared to other establishment system.


- 78 -

Nutrient Management: The average NPK removal by rice based cropping systems range from

554 to 814 kg ha-1 yr-1. for improving the N use efficiency. Subsurface placement of prilled urea, a

urea briquettes and release of fertilizers at 10 cm depth is now possible with zero-till machine in

direct seeded bed planted rice. In low lying and flood prone areas, it is better to have deep band

placement of 80% of recommended N as a basal dose at sowing time. Use of straw increases

availability of other nutrients to crop plant as rice straw (rich in silica) reduces P fixation and

increases the P availability to crop plants (Gillman & Uehara, 2006).

Effect on yield: On an average, yield was significantly higher (40.65 q/ha) in conventional tillage

plot as compared to zero tillage plot (40.00 q/ha). From the above findings it is clear that

conventional tillage plots has lower diseases incidence as compared to zero tillage plots, which is

also reflected in significantly higher yield in conventional tillage.

Table Comparison of yields in Zero (ZT) and Conventional Tillage (CT) conditions in rice during 2000-02

Year Yield (Q/ha)

ZT CT Mean

2000 - - -

2001 40.44 41.38 40.94

2002 39.56 39.92 39.74

Mean 40.00 40.65 -

(Singh,2004)

Resource Conservation Techniques in Wheat

In rice-wheat growing areas, major causes of low wheat yield in sequence with rice was its

late sowing for due to delayed rice transplanting. For better wheat cultivation RCTs such as zero-

tillage/reduced tillage, bed planting and associated agronomic practices, timely farming operation

were found to be good. These techniques improve soil health and are environment friendly and

reduce cost cultivation.

Zero-tillage: Direct seeding of wheat without tillage has gone in most of the areas. Zero-till take

immediate advantage of residual moisture from the previous rice crop, as well as water use is

reduced by about 10 cm-hectare, production cost of wheat is reduced by Rs. 1500-2000 ha-1 by

practicing ZT. Also in Zero-till emergence of crop is earlier than conventional till and weed growth

particularly Phalaris minor is much less in ZT.

Table- Effect of tillage system on weed density

Method of tillage

No. of weeds m-2 Dry weight of weeds at 90 DAS

30 DAS 60 DAS Phalaris minor

Vicia hirsute

C.album (gm-2) total

Zero-tillage 73 46 65 4 0.2 75.2

Conventional 185 113 107 13 3.6 114.9

Gupta, et. al. 2006

Table- Effect of rice establishment methods on grain yield (qha-) of wheat (Pantnagar farm)


- 79 -

2000-01 to 2006-07

Treatment CTW ZTW Mean

Transplanted rice 37.05 36.37 36.71

Wet seeded rice 36.90 36.73 36.82

Dry seeded rice 38.40 39.37 38.89

Zero-till rice 37.89 38.25 38.07

Mean 37.51 37.75

Table- Economics of wheat under different establishment method in rice-wheat system

(Mean of two season)

Establishment method Rs. ha-1

Total cost Gross return Net return

Dry seeded rice

Conventional till rice 11945 43615 31670

Zero-till rice 10677 45009 34332

Wet seeded rice

CTW 13085 42533 29448

ZTW 10677 44377 33700

Transplanted rice

CTW 13085 39197 26112

ZTW 10677 41511 30884

(Gupta et.al. 2006)

Effect of tillage systems on incidence of diseases

Comparative incidence of diseases in zero and conventional tillage conditions in rice during

2000-03

On the basis of overall mean, the incidence of all the diseases (brown rust, yellow rust,

powdery mildew and foliar blight) were more in zero tillage plot than in conventional tillage plot. No

significant difference was observed in interaction of year and tillage conditions on the incidence of

diseases. The reason of lower incidence of diseases on conventional tillage plots may be due to

changed micro-climate which is created by conventional tillage.

Table Incidence of diseases in zero (ZT) and conventional tillage (CT) conditions in wheat

during 2000-03

Year Brown rust (infected leaves per 10 plants)

Yellow rust (infected leaves per 10 plants)

Foliar blight (infected leaves per

10 plants)

Powdery millldew (infected leaves per 10 plants)

ZT CT Mean ZT CT Mean ZT CT Mean ZT CT Mean

2000-01 0.00 0.00 0.00 15.15 10.93 13.04 20.49 15.23 17.86 4.81 4.01 4.41

2001-02 0.00 0.00 0.00 14.84 14.25 14.54 19.06 16.54 17.80 4.29 3.96 4.13

2002-03 4.73 1.42 4.73 17.88 16.44 17.16 23.11 20.29 21.17 5.60 5.69 5.65

Mean 1.50 0.47 - 15.95 13.87 - 20.88 17.36 - 4.93 4. 55 -

Furrow Irrigated Raised Bed Planted System (FIRBS): FIRBS method of planting wheat is

proving to be boon in water scare areas. In this method beds are formed and drilled with FIRBS

planter. Through this technology 25-40% seed and 25% N can be saved without any yield

reduction. FIRBS reduce the water usage by 25-40%. This method provides on the opportunity of


- 80 -

mechanical weeding in furrow and on the top of beds. The crops such as soybean, maize, cotton,

rice, pea, mustard etc., have been successfully grown on beds. This also facilitate inter-cropping

and adjustment of other crops.

Comparative incidence of diseases in FIRBS and conventional tillage plot in wheat crop

during 2000-03

On an average, higher incidence of all the diseases (brown rust, yellow rust, powdery

mildew and foliar blight) were recorded in conventional tillage plot as compared to FIRBS plots.

There was no significant interaction effect of year and tillage condition on the incidence of

diseases.

Table incidence of diseases in FIRBS and conventional tillage plot in wheat crop during

2000-03

Year Brown rust (infected leaves per

10 plants)

Yellow rust (infected leaves per 10 plants)

Foliar blight (infected leaves per 10 plants)

Powdery millldew (infected leaves per

10 plants)

FIRBS CT Mean FIRBS CT Mean FIRBS CT Mean FIRBS CT Mean

2000-01

0.00 0.00 0.00 23.00 23.33 23.17 26.67 30.33 28.50 2.67 2.33 2.50

2001-02

0.00 0.00 0.00 13.15 13.75 13.63 18.33 19.00 18.67 4.50 5.00 4.75

2002-03

3.08 3.25 3.23 19.92 20.17 20.04 22.75 25.33 24.04 3.75 4.33 4.40

Mean 1.03 1.08 - 18.81 19.08 - 22.58 24.89 - 3.36 3.89 -

(Singh,2004)

Surface Seeding: This technology performs well where wheat sowing is not possible due to wet

field conditions after paddy harvest. In these areas, dry or soaked seed can be broadcasted a few

days before or immediately after harvest of rice under wet condition. Generally heavy textured soil

are more suitable for surface seeding as compared to light textured soil. This practice doubles the

cropping intensity in areas where only a single crop is possible due to wet soil conditions following

paddy harvest.

Time of Planting: Most suitable sowing time is considered when the mean daily temperature drop

down to 22-230C. if temperature goes above 250C at germination phase, the seedings are likely to

be seriously attacked by fungal organism. This produces very few tillers, make sparse growth and

come to heading very early and finally yield is poor. Long duration varieties of wheat like UP 2338,

PBW 343, WH 542, HD 2687 and PBW 502 should be sown in first fortnight of Nov, where as UP

2425 and Raj 3765 sown in second fortnight of Nov, under irrigated conditions.

Method of Sowing: Sowing of wheat by Pantnagar Zero till ferti seeddrill, rotatory tillage, FIRB

system and surface seeding are better than broadcast.

Effect on yield: Significantly higher yield (45.91 q/ha) was recorded during 2001-02 followed by

2000-01 (40.44q/ha) and 2002-03 (38.29q/ha). On an average yield was higher in conventional


- 81 -

tillage plot as compared to zero tillage plot. From the above results it can be concluded that lower

incidence of disease was the reason of higher yield during 2001-02.

Table Comparison of yields in Zero (ZT) and Conventional Tillage (CT) conditions in wheat

during 2000-03

Year Yield (Q/ha)

ZT CT Mean

2000-01 39.00 39.00 40.44

2001-02 45.38 45.38 45.91

2002-03 37.94 37.94 38.29

Mean 40.77 40.77 -

(Singh,2004)

Table Economics of zero and conventional tillage in wheat

(A) Operational cost Zero tillage Conventional tillage

(i) Labour 1815.56 2233.14

(II) Machine 1802.26 3719.20

(iii) Irrigation 795.72 795.72

Total (A) 4413.54 6748.06

(B) Material cost

(i) Seed 987.50 987.50

(ii) Fertilizers and Manure 2850.86 2850.86

(iii) Plant Protection Chemicals 3800.00 3800.00

Total (B) 7638.36 7638.36

Total cost (A) + (B) 12051.90 14386.42

(i) Yield (q/ha) 40.77 40.77

(ii) Rate Rs./q 600.00 600.00

(iii) Gross return Rs./ha 24462.00 24462.00

(iv) Net return Rs./ha 12410.10 10075.58

(v) Benefit –cost ratio 1.03 0.70

(Singh, 2004)

It is clear from the above table that zero tillage plot was superior to conventional tillage plot

in terms of benefit cost ratio. Technology provided about Rs. 2335.00/ha higher return as

compared to conventional tillage mainly on account of saving in operation costs.

Disease Situations in Resource Conserving Techniques

Reduced tillage can have an impact on the types of diseases and their severity vis-a-vis

traditional ploughing. This is mostly due to the impact of reduced tillage on the soil structure, the

amount of crop trash and fungal bodies on the soil surface.

Take- all

Changes in soil structure are important for disease, since a good structure is ideal for

healthy root development, allowing a crop to grow away from disease. If the soil is wet or

compacted, it can limit root development and allow root diseases such as take-all to attack the

roots. Take-all is however influenced most by crop rotation and is best controlled by ensuring that

there is a break from cereals between wheat crops.

Table % take all on roots in three seasons


- 82 -

Year 2002 2003 2004 Average

Reduced tillage 47 55 9 37

Ploughed 56 60 10 42

Source: Crop Protection in Reduced Tillage Systems, 2006, TN580

Common eyespot

The stem base disease common eyespot, is primarily spread through crop trash from

previous crops. We would therefore expect higher levels of disease in reduced tillage crops, where

there is more trash on the soil surface. This observation suggests that crop debris on the surface

is not enough to increase the risk. It is possible that antagonists to common eyespot are also

greater where there is a high level of trash. Alternatively, partially inverted trash may allow the

eyespot fungus to overwinter more than eyespot fungus present on the surface.

Table % eyespot on stem base

Year 2002 2003 2004 Average

Reduced tillage 41.7 30.6 20.3 31

Ploughed 39.0 35.6 32.6 37

Source: Crop Protection in Reduced Tillage Systems, 2006, TN580

Fusarium

Fusarium is a common soil fungus which can attack the stems and also infect the ears,

leading to potential mycotoxin issues. The researches have confirmed that reduced tillage did lead

to an increase in stem base Fusarium in 2002 where disease levels were highest. Levels of head

Fusarium were low, but more attention will be needed to ensure good control of head Fusarium

under reduced tillage.

Ergot

Ergot is a disease which can attack a wide range of grasses. It is a problem because the

fungal bodies which develop on the heads and which are harvested with the grain are poisonous.

Previous outbreaks tend to be associated with open flowering varieties of triticale, rye, wheat and

barley. Where the weather is cool at flowering, it can prolong the flowering period, increasing the

risk of infection. Ergots which fall to the ground generally survive no more than one year. Where

they are buried by ploughing, they will not be a source of disease. In a reduced tillage situation,

ergots will remain on or near the surface, so there is a greater risk of infection in a second year. A

greater increase in cereal volunteers may also increase the risk of carry over between cereal

crops. Where disease levels become high, ploughing will need to be considered to bury the ergots

on the surface.

Cephalosporium leaf stripe

In the majority of cases, the disease is no more than a curiosity, but there are cases in

Scotland under reduced tillage, where yield losses can be excessive. These cases tend to be heavy

clay continuous wheat fields where the trash is incorporated into the field. This is not surprising given


- 83 -

the fungus is a slow growing fungus which carries over in trash. As such, there are usually warning

signs of a serious problem developing in a field over 2-3 years. The yield loss is predominately due

to excessive number of small tillers which die early, hence having poor grain fill.

A complete break from wheat (and preferably barley, oats, grasses and volunteers) for at

least two years and in severe cases three years, is the best way to get disease levels back under

control. There is evidence in the USA and also Scotland that a single year break is insufficient time

to eradicate the problem. Seed treatments are not known to prevent the problem. This is not

surprising for a soilborne disease. Again in the USA there are indications of varietal differences,

but there is insufficient information on the susceptibility of UK varieties.

Conclusion

It can be concluded that RCT’s in seed crop health can be crucial for ensuring quality seed

production at economical cost to help achieve sustainable food production in India. Production

capacity, production efficiency and crop protection are the major pillars supporting the national

productivity. The major challenges involved in the agriculture are replacing the traditional tillage

practices and better utilization of the conservation practices by educating and training the farmers

and extension functionaries in RCT. In long run, no technology option will alone be sufficient to

maintain food security or preserve soil and water resources. Thus, policies are needed to be

framed and implemented to promote on large scale the efficient use of RCT in all kinds of

production systems.

REFERENCES

1. Bisht, P.S.; Pandey, P.C. and Singh, D.K. (2006). Effect of different sources of nutrients on rice yield and nutrients status in rice-wheat cropping. Extended summary. Golden Jubilee National Symposium on Conservation Agriculture and Environment. Oct., 26-28, 2006, at New Delhi. On page 193-194.

2. Grover, D.K. and Sharma, T. (2007). Zero-tillage-A profitable and resource saving technology, Indian Farming, April issue.

3. Gupta, R. ; Jat. M.L.; Singh, S.; Singh, V.P. and Sharma, R.K. (2006). Resource conservation technology for rice production. Indian Farming. 57(7):42-45.

4. Sahu, J.P.; Singh, N.P.; Kaushik,M.K.;Sharma,B.B. and Singh,V.K.2002.Effect of Rhizobium phosphorus and potoash application on the productivity of lentil. Indian J.Pulses Res.15 (1): 39-42.

5. Singh, N.P.; Sachan, R.S.; Pandey, P.C. and Bisht, P.S. (1999). Effect of decade long term fertilizer and manure application on soil fertility and productivity of rice-wheat system in Mollisol. J. Indian Soc.Soil Sci. 47 (1): 72-80.

6. Singh, K.P. (2004), IPM in Rice-Wheat Cropping System. Research Bulletin. No. 138. Microsoft Technoprint (I) Pvt. Ltd. Dehradun. 67p.


- 84 -

Advances in Breeding and Seed Production Techniques of Cucurbits

D.K. Singh Department of Vegetable Science, G.B.P.U.A.&T., Pantnagar-263145 (Uttarakhand)

The cucurbitaceae consists of about 118 genera and 825 species. The cucurbits share

about 5.6% of the total vegetable production of India and according to FAO estimate, cucurbits

were cultivated on about 42.9 lakh ha with the productivity of 10.52 t/ha. According to an estimate

India will need to produce 215mt vegetable by 2015 to provide food and nutritional security at an

individual level and being the largest group of vegetable, cucurbits provide better scope to

enhance overall productivity and production. Investment in hybrid technology is particularly

relevant for developing countries, where feeding the increasing population in the face of

decreasing agricultural areas and a declining resource base, already poses formidable problems.

This is a real option to meet huge production increases that are required in the decades ahead.

Presently about 15% of area of vegetable is under hybrids. The term hybrid variety is used to

designate F1 populations that are used for commercial planting. The F1s are obtained by crossing

genetically unlike parents. Rapid advances in plant breeding and associated seed production

technologies have served to enhance the competitiveness of hybrids by increasing crop and seed

yield per hectare reducing the cost involved and improving seed quality. Therefore, the

exploitation of hybrid and different seed production technologies involved for cucurbits have been

discussed.

Cucurbits

The commonly grown cucurbits are listed below with their Hindi name, English name and

botanical name:

Hindi Name English Name Botanical Name

Kheera Cucumber Cucumis sativus

Kharbuza Muskmelon Cucumis melo

Turbuz Watermelon Citrullus lanatus

Lauki Bottle gourd Lagenaria siceraria

Kaddu Pumpkin Cucurbita moschata

Karela Bitter gourd Mormordica charantia

Chikani Torai Sponge gourd Luffa cylindrica

Nasadar Torai Ridge gourd Luffa acutangula

Parwal Pointed gourd Trichosanthes dioica

Petha Ash or wax gourd Benincasa hispida

Tinda Round melon Praecitrullus fistulosus

Kakri Long melon Cucumis melo var. utilissimus

Chichinda Snake gourd Trichosanthes cucumerina

Chappan Kaddu Summer squash Cucurbita pepo

Vilayati Kaddu Winter squash Cucurbita maxima

Askas Chayote Sechium edule

Kakora Kakora Momordica sinensis

Phoot Snap melon Cucumis melo var. momordica

Kundru Ivy gourd Momordica cochinchinensis

Send Mango melon Cucumis melocultus


- 85 -

Area, Production and Productivity of Cucurbits in World and India

Group of Cucurbits Area (ha) Production (mt) Yield (mt/ha)

Cantaloupes and Melons World India

1297077 31500

27179268 645000

20.95 20.48

Cucumber and Gherkins World India

2345625 18000

39840104 120000

16.98 6.67

Pumpkins, Squash and Gourds World India

1462934 360000

18980901 3500000

12.97 9.72

Watermelon World India

3431973 20000

93099266 255000

27.13 12.75

Source: Anonymous (2004) FAO website: www.fao.org

Breeding Achievement

A. Open-Pollinated Varieties

Cucurbits OP Variety

Muskmelon Pusa Sarbati, Hara Madhu, Pusa Madhuras, Arka Rajhans, Arka Jeet, Durgapura Madhu, NDM-15 Punjab Rasila, Arka Rajhans, Hisar Madhur, RM-43, RM-50, Kashi Madhu

Watermelon Durgapura Meetha, Arka Manik, Durgapura Kesar, Durgapura Lal

Bitter gourd Priya, RHRBG-4-1, KBG-16 Coimbatore Long, Pusa Do Mausmi, Pusa Vishesh, Punajb-14, Kalyanpur Baranasi, CO-1, CO-2, Balam Pear, Coimbatore Green, Arka Harit, Kalyanpur Sona, Hirkani, Prithi Priyanka, Punjab-14.

Pumpkin CM-14, Pusa Vishwas, Arka Chandan, Arka Suryamukhi, CM-350, NDPK-24, CO-1, CO-2, Narendra Amrit, Lashi Harit, Azad Kaddoo-1, Pusa Vikas, Suvarna

Cucumber Swarna Ageti, Swarna Sheetal, Japanese Long Green, Pusa Uday, Himangi, Swarna Poorna, Sheetal, CO-1

Ridge gourd Swarna Manjari, Arka Sumit, Swarna Uphar, CO-1 PKM-1, Arka Sujat, Pusa Nasdar, Punjab Sadabahar, Haritham, Hisar Kalitori

Bottle gourd Pusa Naveen, Narendra Jyoti, NDBG-132, Arka Bahar, Pusa Sandesh, Pusa Summer Prolific Round, Pusa Summer Prolific Long, Punjab Round, Punjab Long, Punjab Komal, CO-1, Narendra Dharidar, Narendra Shishir, Kashi Ganga, Kalyanpur Long Green, Azad Harit, Azad Nootan

Sponge gourd Pusa Chikni, CHSG-1, JSGL, Pusa Supriya, Pusa Sneha, PSG-9 Rajendra Nenua-1 Kalyanpur Torai Chikni Azad Torai-1

Ash gourd Pusa Ujjwal, CO-1, CO-2, Mudliar, Indu, KAU Local, Kashi Dhawal, PAG-3

Long melon Arka Sheetal, Punjab Long melon-1

Round melon Arka Tinda, Punjab Tinda

Snake melon CO-1, CO-2, PKM-1, Kaumudi, Baby, H-8, H-371, H-372, IIHR-16A

Summer squash

Punjab Chappan Kaddu-1, Patty Pan, Australian Green

Snap melon Pusa Shandesh, Grism Bahar, Kwari Bahar

http://www.fao.org/


- 86 -

B. Cucurbits Hybrids

Cucurbits Hybrid variety

Muskmelon MHY-5, Pusa Rasraj, Punjab Hybrid-1, MHY-3, MHL-10, DMH-4

Watermelon Arka Jyoti, RHRWH-12

Cucumber Hybrid No.1, Pusa Sanyog, AAUC-1, AAUC-2

Bottle gourd NDBH-4, Pusa Manjari, Pusa Hybrid-2, NDBGH-7, Kashi Bahar, Azad Sankar-1

Bitter gourd Pusa hybrid, NBGH-167, RHRBGH-1

Summer squash Pusa Alankar

Pumpkin Pusa Hybrid-1, NDPKH-1

Seed Production Techniques

Climate

Most of cucurbits require long period of warm preferably dry weather for successful growth.

They do not withstand even light frost. A warm period of 120-150 days is essential. Generally 21-

30° C temperature is favorable for proper growth and development.

Land Requirement

Land should be free from volunteer plants and soil should be well drained and aerated.

Cucurbits can be grown in almost any fertile and well drained soil. For early maturity, the light soil

such as sandy loam or silt loam is best however for high yield heavy soil is preferred.

Isolation

Cucurbits are cross pollinated in nature and cross pollination is done by insect. For pure

seed production an isolation distance all around the seed field is required to separate it from the

field of other varieties, field of some varieties not confirming varietal purity and from wild cucurbit

species. An isolation distance of 800 m. for foundation, 400 m. for certified and 1500 m. for

hybrid seed production should be maintained.

Sowing Time

North- Summer-Jan-Feb, Kharif-July-Aug.

South-Oct-Nov

Seed Rate

S.N. Name of Crop Seed rate (kg/h.) Distance

1. Bitter Gourd 4.0-6.0 Hills are prepared at proper spacing by adding organic matter and 3-4 seed per hills are sown. 1.5-2.5 cm depth is optimum. 9 inches deep furrows are made at proper spacing. Seeds sown on ridge of furrows either on one side or bottom.

2. Bottle Gourd 3.5-6.0

3. Cucumber 2.0-3.5

4. Water Melon 3.0-7.0

5. Ridge gourd 3.0-5.0

6. Sponge Gourd 3.5-5.0

7. Musk Melon 2.5-3.5

8. Snake Gourd 5.0-6.0

9. Ash Gourd 5.0-7.0

10. Pumpkin 5.0-8.0

11. Squash 8.0-10.0

12. Long Melon 2.5-3.5


- 87 -

Manure and Fertilizers

In general practice 30-35 tons well rotten organic manure per hectare is added at land preparation

time. In addition to this following chemical fertilizer may be added

Crop N (kg) P(kg) K (kg)

Water melon 80 60 60

Cucumber & Musk Melon 60 50 50

Other cucurbits 60 30 30

Hybrid Seed-

Why F1 Hybrids?

In general, hybrids offer opportunities for improvement in:

1. Productivity

2. Earliness

3. Uniformity

4. Quality

5. Deployment of dominant genes conferring resistance to diseases and pests

6. Adaptability

7. High prices for seed producers

8. Built-in-exclusivity conferred by the ownership and maintenance of the parent lines of a

successful hybrid.

Hybrid Seed: Current Status

1. Hybrids are considered as one of the most important ingredients to achieve current status

of vegetable production in world scenario.

2. Hayes and Jones (1916) first suggested the exploitation of heterosis in vegetable crops.

3. F1 hybrid eggplants were used at commercial scale in Japan since 1925.

4. First report of hybrid vigor flashed at national level by IARI in chilli during 1933.

5. First hybrid of bottle gourd “Pusa Meghdoot” in 1971 and after two years in 1973 hybrids of

summer squash (Pusa Alankar) and cucumber (Pusa Sanyog) were developed.

6. Beginning of hybrid research persuaded private sector under taking and Indo-American

Hybrid Seed Company released hybrids of tomato “Karnataka” and capsicum “Bharat” in

1973 for commercial cultivation

7. Introduction of new seed policy declared in 1988.

8. ICAR New Delhi started big programme “Promotion of Hybrid Research in Vegetable

Crops” during 1995.

9. Important private companies conducting research in vegetable include M/S Indo-American

hybrid Seed Co., Namdhari Seed Pvt. Ltd., Ankur Seed, Syngenta India Ltd., Beejo

Sheetal, MAHYCO, Nunhems, Pro-Agro Seeds, Century Seeds, New Delhi.

Steps in Hybrid Seed Production

Production of inbred parental lines. Testing for combining ability (GCA and SCA).


- 88 -

Production of hybrid seed. Maintenance of inbred parents.

Methods of Hybrid Seed Production in Cucurbits

1. Hand pollination – a. Without emasculation b. With emasculation

2. Defloration and insect pollination 3. Use of gynoecious lines and insect pollination 4. Use of genetic male sterility – utilization of morphological markers 5. Use of monoecious line 6. Chemical suppression of male flowers and open pollination.

1. Hand Pollination: a. Without Emasculation

Applicable for monoecious cucurbits (Cucumber, Squash, Pumpkin, Bitter gourd)

Hand Pollination: b. With Emasculation

Applicable for andromonoecious cucurbits

2. Defloration and Insect Pollination

Cucumber, Watermelon, Pumpkin and Gourds (Bottle gourd, Ash & Bitter gourd)

♀♀

Seed parent ♂♂

Pollen parent

Removal of ♂♂ flower

before anthesis

♂♂ flower

Natural cross pollination by bee

F1 Seeds

One medium sized bee colony/ha is enough for good HSP

Isolation distance: 400m Planting ratio: Bottle gourd: 3:1 Squash: 4:1

Female plant Male plant

Hermaphrodite flower Male flower

Pollination (after anthesis)

Emasculation + bagging

(Before anthesis)

Bagging – F1 seed collected

1942- Munger – Hybrid seed production in melons

Cover with cotton

Planting ratio: 6:1


- 89 -

3. Use of Gynoecious Lines and Insect Pollination

Planting ratio (3 gynoecious female line: 1 pollinator line).

Natural pollination by bees.

Any other variety except parents should not be there.

Blending – to improve pollination in gynoecious hybrid seeds (10% monoecious types.

Sumter cultivar – most common blender.

If parthenocarpic gynoecious hybrid – no blending.

Commercial gynoecious hybrids

In cucumber

Pusa Sanyog,

DCH-1, 2 (T.A. More and V.S. Sheshadri in early ninties),

Phule Prachi (Gyc-2) and Phule Champa (Gyc-4) (More, 2002)

In muskmelon

MH-10 (Dhatt et al.,2005)

4. Use of Genetic Male Sterility

Planting ratio (2 female : 1 male)

Planting of 6 seedlings per hill for seed parent

Pierce anthesised flowers from female parent

Tag male sterile plants

Rouging of male plants for 8-10 days

Allow natural pollination

Punjab Hybrid-1 – ms -1 x Hara Madhu

Maintenance: Rouging of male fertile plants from female line by morphological marker trait (male

sterility associated with glabrous foliage in watermelon)

5. Chemical Suppression of Male Flowers

Planting ratio : 5:1 in Cucurbita pepo

2-true leaf stage is most responsive for application of chemicals

Natural pollination/hand pollination.

6. Foliar Spray of PGRS to Induce Increased Proportion of Pistillate Flowers

PGR Conc (mg/l) Cucurbits

Cycocel (CCC) 250-500 Most cucurbits, effective in cucumber

Ethephon (CEPA) 150-200 Most cucurbits

Gibberellic Acid (GA) 150-200 Watermelon

Indole acetic acid (IAA) 10 Snake gourd & bitter gourd

NAA 20-200 Cucumber, melons & gourds

Maleic hydrazide (MH) 25-100

50-150

Cucumber, muskmelon, bottle gourd, ridge

gourd


- 90 -

Flowering Behaviour

Crop Anthesis Dehiscence Availability of viable pollen

Receptivity of stigma

Ash gourd 6-7 hr 3-4 hr 7-16hr 12 hr before to 36 hr after anthesis

Bitter gourd 9-10:30hr 7-8 hr 5-12hr 24 hr before to 24 hr after anthesis

Bottle gourd 17-20hr 13-14 hr On day of anthesis till next

morning

36 hr before to 90 hr after anthesis

Cucumber 4:30-7 hr 4:30-0hr Up to 14 hr 2 hr before to 2-3 hr after anthesis

Muskmelon 5:30-6:30 hr 5-6 hr 5-14 hr 2 hr before to 2-3 hr after

Water melon 6-7:30 hr 5-6:30 hr 5-11 hr 2 hr before to 3 hr after anthesis

Ridge gourd 17-20 hr 17-20 hr On the day of anthesis till 2-3

days after anthesis in winter

and 1.5days in rainy season


Snake gourd 18-21 hr Shortly before anthesis

10 hr before anthesis to 49 hr after dehiscence


Sponge gourd

4-8 hr 4-8 hr On the day of anthesis


Pumpkin 3:30-6 hr 21-3 hr 16 hr after anthesis


Kalloo (1988)

Irrigation

If crops grown in summer, required frequent irrigation preferably in the evening.

Rouging

At least 3 times

Before flowering:

a. Rouging on basis of leaf size, shape and colour, vigor, bushy or training habit.

During flowering and immature fruit stage:

a. Check for flower colour, ovary shape, size, and colour, fruit shape and colour of the

variety to be taken in seed production programme.

Maturity stage:

a. Check the fruits of the seed crop variety, in respect to size. Color and shape.

b. During all the three stages wild species plants as well as mosaic affected plants.

Invariably be rouged out.

Harvesting

Cucurbits should be allowed to reach full maturity stage to get the seed of higher germination. In bottle

gourd, sponge gourd and ridge gourd along with some others do not pose problem for maturity but in

case of muskmelon and water melon more care needed to harvest only matured fruits.


- 91 -

Seed extraction

It is more important to extract the seed from the matured fruits at appropriate time and method to

be used to separate the seed; because slight ignorance may deteriorate the germination. In bottle

gourd, sponge gourd and ridge gourd fully ripened and dried fruits are crushed and seeds are

separated.

Yield

S.N. Name of crop Seed yield/ha. (Kg)

Bitter Gourd 60-120

Bottle Gourd 60-120

Water Melon 200-400

Musk Melon 100-300

Cucumber 100-300

Ridge gourd 80-120

Sponge Gourd 80-120

Snake Gourd 80-120

Ash gourd 100-150

Pumpkin 150-350

Seed Certification Standards

(Field standard specific requirements)

Seed standard Foundation Certified

Pure seed (maximum) 99.0% 99.0%

Inert matter (maximum) 01.0% 01.0%

Other crop seed (maximum) 0.05% 0.01%

Weed seeds (maximum) None None

Objectionable weed seed (maximum) None None

Other distinguishing varieties (maximum) 0.1% 0.2%

Germination (minimum) 60% 60%

Moisture (maximum) 07.0% 07.0%

For vapor proof containers (maximum) 06.0% 06.0%

Factor Max permitted (%)

Foundation Certified

* off-type 0.10 0.20

Objectionable Weed plant None None

Plants affected by seed borne- disease only in musk

melon

0.10 0.20

Plants affected by virus disease 0.10 0.2


- 92 -

REFERENCES

1. Anonymous. 2004. FAO website: www.fao.org

2. Dhatt, A.S., Singh, Malkit, and Sidhu, A.S. 2005. Studies on F1 hybrid seed production of gynoecious line in muskmelon. In: Abstracts: National Seminar on Cucurbits, GBPUA&T, Pantnagar. 22-23 September, 2005. pp. 90.

3. Hayes, H.K. and Jones, D.F. 1916. First generation crosses in cucumber. Ann. Rep. Conn. Agric. Exp. Sta., 1916. 319-322.

4. Kalloo, G. 1988. Vegetable Breeding. Vol. 1, CRC Press, Inc. Boca Raton, Florida. pp. 24-27.

5. More, T.A., Nishimura, S., Ezura, H., Matsuda, T. and Tazake, A. 2002. Development and exploitation of tropical gynoecious lines in F1 hybrid of cucumber. Acta Hort. 588: 261-267.

6. Munger, H.M. 1942. The possible utilization of first generation muskmelon hybrids and an improved method of hybridization. Proc. Amer. Soc. Hort. Sci. 40: 405-410.

http://www.fao.org/


- 93 -

Integrated Disease Management for Vegetable Seed Production

S.N. Vishwakarma Department of Plant Pathology, G.B.P.U.A.&T., Pantnagar-263145 (Uttarakhand)

Vegetable are important source of dietary, minerals and vitamins. All the developed and

developing countries realize the importance of vegetables as an essential diet due to medicinal

and nutritional value for human health. There is steady upward trend in vegetable production.

China is ranking first in world and currently produces 237 million tons of vegetables. India has a

quantum jump in vegetable production securing the second positions in the world. The total

production of vegetable is more than 91 million tons in the country. In spite of this, the productivity

of vegetable per unit area is very low. Thus the produces at present is approximately half of the

requirement as per dietary standard against 250-300gms/ day/adult. Vegetable being more

succulent and rich in nutrient are more prone to disease infection, thereby incurring high yield

losses during pre and post production period. Disease pressure in vegetable crop from seedling

stage to harvest caused by mainly fungi, bacteria and virus are the most important constraints for

low production of vegetable seeds.

Management of vegetable diseases-An over view:

The survey of literature reveals that vegetables either grown directly or through

transplanted seedling suffer from a variety of biotic, mesobiotic and abiotic causes. Control

methods invariably recommended includes cultural practices, host resistance, chemical control,

physical and biological control methods. Individually different methods have been recommended

for management of different disease, but among the recommendation application of pesticides is

really high and thereby posing problems of residue poisoning, pest resistance and economic.

Under this situation application of integrated disease management (IDM) appears most

appropriate as production is to increase and harmful effect of pesticide is to decrease.

Integrated Disease Management (IDM):

The philosophy, principles and objective of IDM state that “A desirable approach to the

selection, integration and use of methods on the basis of their anticipated economic, ecological

and sociological consequences”. Under the concept of disease management reduction in losses

cause to vegetable must take into account that following criteria for developing IDM schedules:

Develop the schedule which is economical. The cost of application and loss due to disease

must be proportionately balanced in favour of producers.

The schedule development fit in the production protection schedules practiced by the

growers.

The schedules developed must strive to manage most pest and disease simultaneously in

the crop concerned.

To ensure success the IDM schedule in the vegetables need to be applied as community

programme and /or cooperative programme.


- 94 -

Management of vegetable diseases: The existing technology:

Based on nature of vegetable diseases, the control strategies could be prophylactic or host

resistance. The principle of prophylaxis could be achieved by applying the principle of exclusion,

eradication and protection. To achieve exclusion method such as quarantine, inspection and

certification and seed treatment have been recommended. In order to achievement the eradication

of inoculum methods like biological control, crop rotation, rouging, crop refuse destruction,

sanitation including distruction of collateral and alternate hosts have been recommended.

In protection, those practice which function as a barrier between host and pathogens (no

contact). The practices are cultural practices such as methods of planting, time of

sowing/transplanting, balanced fertilizer; controlled irrigation, spray of micro nutrients and

application of pesticides, fungicides, antibiotics, nematicide etc. are recommended.

Principally, the use of resistant genotype looks the best method for diseases management.

The methods used to develop resistant genotype are introduction, selection, and hybridization, and

mutation, biotechnological and molecular technique. Development and use of resistant genotype is

continuous and never ending process due to evaluation of new biotype/pathotype/races. The

resistant is broken down as a matter of fact development of resistant to disease in vegetable is yet

to get place and recognition given to place cereals and pulses.

Guide lines for developing IDM:

Vegetable are raised repeatedly following the principles of intensive farming. This practices

favour survival of primary inoculum and subsequently infection and spread of secondary

inoculum in the crops. To ensure success of any IDM schedule the impact and the effect of

intensive cultivation on diseases must be the major input in developing the schedule.

The vegetable in India is still today are grown on small scale. Cucurbits and beans are

grown ever around the house and the crops are reserviour of inoculum of number of

pathogens as no control measure is invariably applied. This major source of inoculum must

also be considered for developing the schedule.

The schedule develop must be easy approachable and effective to be used at community

or co-operative level.

Development of IDM schedule for diseases of brinjal-An example: Brinjal suffers due to

disease caused by Fungi, Bacteria, Viruses, Phytoplasma and Nematodes. However, among the

disease, damping-off (in nursery), Alternaria leaf spot, Cercospora leaf spot, Phomopsis blight and

fruit rot, Sclerotinia blight and fruit rot, Bacterial wilt and Root-knot are the most important ones.

The primary inoculum of the diseases listed above survives either in/on seed or soil as resting

structures or the infected crop debris as facultative saprophyte. The secondary inoculums

produced after infection, disseminate through the agency of air, water, insect and during

intercultural operations and therefore schedule development must attack initial as well as

secondary inoculums.


- 95 -

The schedule

i. Use raised nursery bed and soil should be solarized, maintain plant density and soil

moisture.

ii. Avoid frequent irrigations and heavy nitrogen application.

iii. Use healthy and certified seeds.

iv. Treat seed by physical and chemical means using heat or fungicide. Among fungicide,

Thiram, Captan@ 0.25%, Carbendazim @ 0.1%, Apron @ 0.4%.

v. Destruction of crop debris, deep summer ploughing, organic amendment, crop rotation,

date of sowing/transplanting to be used as per recommendation.

vi. While transplanting root treatment either with fungicide or bio-agent.

vii. Application of nematicide /fungicide/ for the control of inoculum existing in soil.

viii. Foliar application of required pesticides.

ix. Use of resistant/to tolerant varieties/ cultivars.

Table: Minimum field standards for diseases in certification of vegetable seed production.

Sl. No.

Crop Named of disease

Causal organism (s) Maximum disease level at flowering/poding stage(%)

Foundation seed

Certified seed

1. Brinjal Phomopsis blight and fruit for

Phomopsis vexans 0.10 0.50

2. Cabbage and Cauliflower

Black leg Black rot and Soft rot

Phoma lingam X. campestris pv. campestris Erwinina carotovora pv. carotovora

0.10 0.50

3. Capsicum and Chilli

Anthracnose Colletotrichum capsici 0.10 0.50

4. Muskmelon Mosaic Cucumber mosaic virus 0.10 0.20

5. Raddish Black rot and Black leg

X. campestris pv. campestris Phoma lingam

0.10 0.50

6. Tomato Early blight/leaf spot, mosaic

Alternaria solani Tobacco mosaic virus

0.10 0.50

7. Turnip Black rot X. campestris pv. campestris

0.10 0.50

REFERENCE

1. Sherf, F. Ardem and A.A. Macnab 1986. Vegetable disease and their control. Second Ed. A Wiley Inter Science Pub, New Yourk, 727pp.

2. Chaube, H.S and Ramji Singh, 2001. Introductory Plant Pathology, IBD Co. Lucknow PP.341- 360.

3. Singh, R. S. Introduction to Principles of Plant Pathology, Oxford & IBH Publishing Co. New Delhi, 402 pp.

4. Verm, L.R. & R.C. Sharm. 1999. Diseases of Horticultural Crops (Vegetables, Ornamental and Mushroom) Indus Publishing Company New Delhi, 731 pp.


- 96 -

Seed Cane Health for Sustaining Higher Sugarcane Productivity

S.K. Saini Department of Agronomy, G.B.P.U.A.&T., Pantnagar-263145 (Uttarakhand)

Sugarcane is a important commercial crop occupying 4.4 m ha area with cane productivity

of 67 t/ha. Cane yield losses due to diseases account 19-20% and due to insects account 25-30%.

The major carrier of disease/pest is planting material (seed cane).

Seed cane is sugarcane stalk used for propagation purpose while cane seed is the true

seed of cane arising from natural pollination of the flower. The true seeds differ in characters and

none exactly like the parents. Hence, true seed or fuzz is not used for commercial purpose. The

asexual or vegetative method produces new plants in all respect like the cane from which seed

pieces were taken. That’s why sugarcane is propagated commercially by the vegetative method

using seed canes / setts.

Sugarcane seed material is traded in different forms in the country. In the northern region it

is generally in the form of seed canes whereas in the southern region it is in the form of sugarcane

setts.

Setts are parts of stripped canes, each having two three buds (one at each node) obtained

by cutting the canes across with a sharp instrument. Setts obtained from top portion of the canes

may have more buds, but they shall not be more than six.

The millable cane meant for sugar extracting is possesses different quality parameter than

the seed cane meant for planting. The seed cane should meet the following seed quality

standards.

Table 1: Seed cane quality standard

Attributes Values

Sett moisture >8-65%

Nodes with viable/soot bud <5.0%

Nodal roots >5.0%

Lodged cane >10.0%

Dried cane >62.0%

Germ inability of buds >85.0%

Swollen/sprouted buds beyond 1 cm from rind >5.0%

Genetic purity 99.9%

Physical purity 98.0%

Crop management for healthy seed cane production

Selection of planting material

Use of quality seed is highly important to establish a good initial crop stand and thus to

ensure a good crop. In India, sugarcane planting and harvesting operations coincide in most

places. Farmers usually drawn setts from the crops that are being harvested. Selection of planting

material is one of the important aspects which is grossly neglected by the cane farmers. Selection

of suitable planting materials and subjecting them to various treatments before planting are the key


- 97 -

to healthy crop. Preference should be given to healthy seed materials; free from pests and

diseases like red rot, wilt, smut etc. The top one third to half portion of a cane being comparatively

immature, has buds of high viability and is the best for planting. The tops are inferior with regard to

sugar content therefore, when top setts or cuttings are used for planting, less sugar is wasted.

Moreover, top portion contains healthy buds, more moisture, nutrients and reducing sugars, which

helps in quick and better germination. The upper buds are protected by leaf sheaths, which

conserve their germination ability. Bottom portion of cane is rich in sugar and takes a long time in

germination; this should be used in jaggery making. If only upper half of the cane is utilized for

setts, comparatively higher germination is secured. Seed cane should be taken from well

manured, erect and healthy crop of not more than 10 month age. Ratoon crop is not suitable for

seed purpose as these canes may carry the disease of the previous crop. Medium thick, fresh and

tender stalks should be selected for planting. The eye bud should be prominent but not over

mature.

If canes are brought from distance place, it is advisable to bring along with leaves to avoid

drying of cane and mechanical damage to the buds.

Srivastava et. al. (1990) reported that the seed material as seed cane crop, shall confirm to

the following;

1. The age of the crop at harvest for seed purpose should be from 8 to 12 months.

2. The seed material should not include any portion of either the floral axis or three internodes

below the highest node of a flowered cane.

3. The seed material should be fresh and the seed setts should be planted within 24 hours of

cutting seed canes.

4. Each node should bear at least one sound bud. The number of nodes without sound buds

shall not exceed 10 per cent by count of the total number of buds per cane.

5. The swollen buds or the buds which have projected out to the extent of more than one

centimeter from the surface of the cutting shall not exceed 5 per cent of the total number of

buds.

6. The seed cane shall be free from sett roots. The number of nodes having sett roots all

round should not be more than 5 per cent of the total number of nodes in the seed cane.

7. The seed material shall be free from splits and splinters caused during harvesting and in

the preparation of setts. Split caused during sett cutting shall not extend beyond the nearby

internode.

8. The seed material should have 80 per cent viable buds. In case of area declared frost

affected, the viability of the buds shall not be less than 50 per cent.

9. The seed material shall be of only one variety. No admixture is permissible.

10. The setts shall be cut in such a manner that the distances of the cut and from the nearest

node shall not be less than 4 cm.

11. The setts should contain moisture as per following standards.


- 98 -

(i) Internodes of lower end - Not less than 60 per cent on fresh weight basis.

(ii) Any other internodes - Not less than 66 per cent on fresh weight basis.

12. The number of sugarcane setts showing a pithy area or cavity more than one fourth of the

total area of the cut end shall not exceed 3 per cent by count of the total number of setts.

13. The seed cane crop be inspected a different permissible stages to meet following standers

tolerance limit of disease and pest for the commercial seed is as under.

Table 2: Field standards (diseases) of seed cane crop

S.No. Factors Stage of field inspection

Maximum permissible limits

foundation Certified

i. Off-types I,II,III None None

ii. Plants affected with designated diseases

- Red rot I,II,III None None

- Smut I 0.02* 0.10*

II 0.01* 0.10*

III None None

- Grassy shoot

II 0.05* 0.50*

III None None

- Wilt III 0.01* 0.01*

- Leaf scald

II 0.01* 0.05*

III None None

Table 3: Field standard (insects) of seed cane crop

Factors Stage of field inspection

Maximum permissible limits

foundation Certified

- Top borer II & III 5.0 5.0

- Internode borer III 10.0 None**

10.0 None**

- Stalk borer III 20.0 None**

20.0 None**

- Plassey borer, Gurdaspur borer, Scale insect, mealy bug

III 5.0 None**

5.0 None**

Preparation of setts

The germination of a bud is controlled by apical dominance which is exerted through

auxins. When apical dominance is removed by clipping off the top bud, the buds below tend to

germinate. Because of this fact instead of planting an entire cane, it is cut in to 2-3 budded setts

usually 30-45cm long.

Sett treatment

To prevent the seed setts from fungal diseases and to improve germination, the setts

should be dipped into 0.5 per cent solution of agallol (3%) or 0.25 per cent solution of aretan (6%)

or tafasan (6%) for 10 minute before planting. Alternatively, setts may be treated with 0.1 per cent

solution of carbendazim (Bavistin).


- 99 -

If setts are brought from long distance, dip for 24 hours in a solution containing 500g lime

in 200 litre of water. This will invigorate the buds. If setts are infested with scale insects, mealy

bugs or white flies, treat with 265 ml of dimethoate (roger) per 100 litre water for five minutes

before planting.

Whenever facilities for hot water treatment are available the setts may be treated for 2

hours at 500C in hot water to check the chronic diseasees like grassy shoot, smut and red rot. In

lieu of this, moist hot air treatment (MHAT), evolved to control setts transmissible diseases be

used. It also sterilizes canes against certain insects like scale, mealy bug etc. In MHAT unit seed

cane be treated with above 95% humidity at 540C for 4 hours. This system is highly useful to

eliminate smut infected buds.

Planting time

Sugarcane crop raised exclusively for seed purpose is known as a ‘short crop’. The short

crop is usually harvested at around 8-10 months. In the case of a short crop, entire stalk can be

used for preparing setts, discarding only the bottom most buds.

As the best age of harvest of a nursery crop is around 8-10 months, the planting date

should be accordingly adjusted. For example, for autumn crop, the nursery planting should be

done from February to March. For spring crop, the nursery planting should be done in April.

Site selection

Saline, alkaline and acidic soils are not suitable. Preference should be given to fertile soils

with good drainage, high organic carbon content and good water holding capacity at least to a

depth of 50 cm. The effective soil depth for adequate root development should be at least 1 m.

The soils should not be too shallow with hard pans as the roots will not penetrate deep; resulting in

lodging and earthing will be difficult.

The pH of soil should be 6.5 to 8.0. If the soils are saline; they need to be amended by

applying gypsum, sulphur and or organic matter. Water logged soils should be avoided for taking

seed crop. The upland field is selected for raising the seed crop. The rain water traversing from

adjoining field is prevented to check spread of red rot.

Field preparation

Sugarcane needs deep tillage. One deep ploughing followed by two cross harrowing or

rotavator are required to prepare good seed bed.

Levelling can be carried out by using a tractor operated leveller. A fairly level bed ensures

a uniform crop stand, proper distribution of irrigation and good crop growth. Sub-soiling is effective

to break hard pan, ensuring better internal drainage.

Seed rate

Higher seed rate is preferred at reduced spacing. For 1.0 hectare land 50,000 three buded

setts or 75,000 two buded setts would be sufficient to raise a good seed crop, by weigh about 80-

85 quintal seed will required for one hectare land.

Other cultural operations


- 100 -

Earthing : Full earthing up is done after the final manuring, at 90-120 days after planting

coinciding with the peak tiller population stage.

Detrashing : Detrashing in some of the varieties results in swelling of buds making them more

liable to mechanical damage. However, problems of some pests like white flies, mealy bugs,

scales etc. are minimized by detrashing.

Propping / wrapping : In order to prevent lodging tying of the crop should be done when it attains

a height of 2.0 meters. Lodged cane is more liable to bud sprouting, hence, seed cane quality in

lodged cane is poor. If needed crop may be propped 2-3 times.

Roguing and cleaning : Roguing of diseased plants, off type plants or the plants of other varieties

is a must to produce good quality and genetically pure seed of sugarcane. So the seed crop

should be inspected carefully at regular internals from germination stage till harvest and kept

scrupulously clean of all pests and diseases. The affected clumps are ronged out as soon as the

symptoms are visible. The crop should be kept free from insects-pests by adopting proper

prophylactic measures.

Nutrient management

To attain faster rate of growth and good quality seed crop higher amount of nutrients and their

late split application is advantageous. Apply well decomposed organic manures (compost, FYM, etc)

@ 20 t/ha or vermicompost @ 5 t/ha at the time of last harrowing and well mixed with soil.

Seed crop should receive 25% more nitrogen and phosphours and 50% more potassium

than those recommended for the commercial crop in region. Generally 180-190 kg N, 80 kg P2O5

and 80 kg K2O per hectare is applied for seed crop. The fertilizer may be given in four split viz, 1/4

N and full phosphorus and potassium as basal remaining nitrogen in equal split at 60, 90 and 120

days after planting.

Mehar Chand et al. (2004) from Karnal (Haryana) reported that sugarcane seed crop

fertilized with 25% more of the recommended nitrogen (150 kg N/ha) gave the highest stalks and

seed cane, cane yield and seed germination. Nitrogen fertilizer application in three equal split at

planting and 60 and 90 days after planting resulted in maximum cane seed, cane numbers and

seed cane yield.

Pre–fertilization

To obtain healthy setts with more moisture, reducing sugars and higher nutrient content

pre-fertilizing the nursery crop about 6 to 8 weeks prior to harvest is suggested. A dosage of 50 kg

N, 25 kg P2O5 and 25 kg K2O per ha may be applied.

Weed Management

Complete weed control cannot be achieved by using any one method. Combination of

different weed control methods is very beneficial to check the growth of different types of weeds.

In general pre-emergence spray of atrazine or metribuzin @ 1.0 kg a.i./ha and post

emergence spray of 2,4-D sodium salt @ 1.0 kg a.i./ha 45 days after planting followed by one

hoeing at 90 days after planting is advantageous.


- 101 -

Irrigation

Frequent irrigation are needed for seed crop. To save the crop from the ill effects of frost,

the seed crop should be adequately irrigated. During the germination phase light irrigation at

frequent internals may be given to facilitate early and uniform sprouting.

During grand growth phase where internode elongation occurs, water requirement is high.

Shortage of water at this stage will result shortening of internodes and thus cane length.

Adequate supply of water during ripening phase leads to continued vegetative growth thus hamper

sucrose accumulation, which is desirable for a good seed cane crop. Irrigate the crop 10-15 days

before the harvesting

Drainage

Drainage of excess water from sugarcane field is an important aspect of water

management. Excess water adversely affects the crop growth and seed cane yield. Drain away

excess water from the field by making drainage channels. Furrow may be used for draining the

water from the field. Under waterlogged condition crop is subjected to lodging and root premordia

start sprouting due to which the quality of seed cane deteriorates greatly.

REFERENCES

1. Anonymous (2006). Sugarcane Seed Cane Standards Sugar Tech News. Vol. 36(4):6-7

2. Mehar Chand, Srivastava, S.N.L. and Tamak, J.C. 2004. Nitrogen management for sugarcane seed crop. Haryana Journal of Agronomy, 2004 (Vol. 20) (No. 1/2) 96-97.

3. Srivastava, S.C., Shukla, U.S., Yadav, R.A. and Banerjii, D.K. 1990. Standards for sugarcane seed material technical bulletin No. 25. Indian Institute of Sugarcane Research, Lucknow. pp. 1-5.


- 102 -

Approaches for Healthy Seed Production in Sugarcane

O.K. Sinha Indian Institute of Sugarcane Research, Lucknow- 226 002 (UP)

Sugarcane diseases cause about 19 per cent losses in cane productivity. Such diseases

are transmitted through seed cane or air/soil. The economically important diseases like red rot,

smut, wilt, ratoon stunting, leaf scald, grassy shoot and mosaic are transmitted through seed cane.

Non-seed transmitted diseases like rust, eye spot, yellow spot, pineapple sett rot, etc., become

occasionally important. Among seed-transmitted diseases, red rot is a dreaded disease which

leads to cent per cent mortality of plants in an affected area.

For healthy seed production in sugarcane, basic requirement is the Nucleus Seed which is

further multiplied to Breeder Seed, Foundation Seed and Certified Seed. For nucleus seed

production, variety resistant to red rot and recommended for the region is selected. Moreover,

nucleus seed crop may get infected by the pathogens of seed transmitted diseases through

various means. For seed production, freedom of seed is absolutely necessary. For this,

thermotherapy of seed cane is practised. Thus, varietal resistance and thermotherapy are two

important aspects for healthy seed production of sugarcane.

i) Varietal resistance: At national level, the sugarcane genotypes are evaluated at

multilocations against red rot, smut and wilt under All India Coordinated Research Project on

Sugarcane. Of these, red rot is given greater emphasis. A few genotypes like Co 7314 and Co

7704 have been identified as a good general combiner sources of resistance to red rot. Several

other genotypes like BO 91 and CoS 767 as well as clones of Saccharum spontaneum are good

sources of red rot resistance. Such resistant donors are being utilized in sugarcane breeding

programme for development of red rot resistant varieties.

Virulence diversity of red rot pathogen (Colletotrichum falcatum) is monitored in the country

every year. So far, 11 pathotypes of this pathogen have been identified, 11 in sub-tropical and 4 in

tropical India. For varietal evaluation, regional pathotypes are used for inoculation purpose.

Biotechnological tools are also being used for developing disease resistant varieties.

However, limited success have been achieved so far. Somaclones resistant to smut, eye spot,

downy mildew and rust have been developed. Attempts have been made through in vitro selection

using pathotoxin of eye spot pathogen. Dual culture of host and pathogen may be useful in

evaluation for resistance.

Recently, plant defence response genes have been identified and could be utilized in

developing transgenics resistant to a disease. Although marker assisted selection for disease

resistance have been successful in some crops, it is yet to be explored in sugarcane.

ii) Thermotherapy : It is an important component of healthy seed production as it has

proved most effective in eliminating seed-borne pathogens. Out of four methods viz., hot water


- 103 -

treatment, moist hot air treatment, aerated steam therapy and hot air treatment, the former three

methods are being practised in different parts of the country.

Hot water treatment: The seed cane is treated at 500 C for 2 to 3 hours. The method is effective

against smut, wilt, leaf scald, ratoon stunting, grassy shoot, mosaic and chlorotic streak

pathogens. Although the therapy is effective, there are certain demerits, e.g., specific heat of water

is 1.0, therefore, the buds may become soft and are liable to be damaged during transport of

treated seed cane.

Hot air treatment: The seed cane is treated in specially designed hot air treatment (HAT) unit

at 540 C for 8 hours. It is effective against grassy shoot and ratoon stunting pathogens. The

treatment is not in practice due to demerits like desiccation of buds, poor germination of buds,

longer duration of treatment and less effective against may other diseases.

Aerated stem therapy: The seed cane is treated at 500 C for 1-3 hours in specially designed

aerated stem therapy (AST) unit. It is effective against grassy shoot, ratoon stunting and smut

pathogens. The specific heat of the medium is 0.5 and therefore, less lethal to buds. It is in

practice in most parts of tropical states of the country.

Moist hot air treatment: The seed cane is treated in specially designed moist hot air treatment

(MHAT) unit at 540 C for 2.5 hours at 95-99 % RH. It is effective against smut, grassy shoot, leaf

scald, ratoon stunting, incipient infection of red rot pathogens.

The specific heat of medium is 0.5 and, therefore, it is less lethal to buds.

Quality seed production:

The quality seed production consists of following steps :

i. Heat treatment of nucleus seed or, if not available, breeder seed. The latter can also be

produced through tissue culture raised plants adopting recommended protocol.

ii. Production of Foundation Seed from Breeder Seed. At each stage, the seed is multiplied

about 10 times by conventional method of planting. The seed crop is monitored for the

presence of designated diseases and insect pests by trained technical personnel. The

affected plants clumps are uprooted.

iii. Production of Certified Seed from Foundation Seed. Again, the Seed is multiplied 10

times by conventional method of planting. The seed crop is monitored as in case of

Foundation Seed. Certified seed is made available to the sugarcane growers for

commercial cane production. It is recommended that after 5 years of commercial

cultivation, the planting should be done with certified seed to contain the diseases and

insect pests in the field.


- 104 -

Detection of Smut and Red Rot Pathogens in Sugarcane for Production of Healthy Seed

O.K. Sinha

Indian Institute of Sugarcane Research, Lucknow- 226 002 (UP) Of economically important seed transmitted diseases of sugarcane, smut and red rot are of

greater significance in sugarcane cultivation especially in seed production. The spread of the two

diseases takes place primarily through inadvertent movement of infected seed material, as the

incipient infection cannot be distinguished. The only dependable method for detection of the

pathogens is through planting the setts and wait for appearance of symptoms.

Due to this constraint, the methods of in situ detection of the two pathogens have been

developed as detailed below:

1. Detection of smut pathogen (Ustilago scitaminea Syd.) in nodal buds of sugarcane by

stain technique

Nature of disease

Smut of sugarcane is a systemic disease. The fungus colonizes the meristematic tissue of

nodal buds and apical meristem.

During development of plant (mother shoot and tillers), the fungus is seated in nodal buds

present at each node and in apical growing point.

Material required

1. Naturally infected bud

2. Forceps

3. Scalpel/blade

4. Distilled water

5. Trypan blue stain (0.1%)

6. 1-N Sodium hydroxide solution (6%)

7. Ethanol (80%)

8. Lactophenol

9. Hot plate

10. Micro-slide & cover-slip

11. Light microscope

Methodology

1. Scoop out nodal bud with the help of scalpel.

2. Take thin cross sections of infected bud from basal side till circular rings of bud scales are

visible.

3. Press the bud so that growing point is ejected. Pick it with forceps.

4. Put growing point in Trypan blue + NaOH (1:1, v/v) solution for 3.5 hours.

5. Remove and wash in distilled water. Put in ethanol for 2 min for dehydration.


- 105 -

6. Place in lactophenol and heat to boiling for 2 min.

7. Mount on microslide.by giving slight pressure on coverslip.

8. Observe blue stained hyphae under light microscope.

Under light microscope, the infected growing point shows a network of blue-stained hyphae

of the fungus.

Applied value of the stain technique

1. Help estimate the percentage of smut infected buds in seed lot (setts). Thus, of significance

at quarantine station and healthy seed production.

2. Screening of smut susceptible genotypes.

2. PCR-based detection of smut pathogen in infected tissue (nodal bud or apical meristem)

Methodology

1. Excise nodal bud/apical dome

2. Take out growing point tissue

3. Isolate DNA

4. Amplify DNA using internal trancribed spacer regions (ITS 4 & 5) of rDNA followed by

electrophoresis.

5. PCR product of – 460 bp is observed.

3. PCR – based detection of red rot pathogen (Colletotrichum falcatum Went)

Nature of disease

Red rot is not a systemic disease, but can affect all the plant parts, mainly the stalk where

rotting of pith tissue takes place. At later stage, whole plant dries. The incipient infection is

confined mainly to leaf scar region.

Methodology

1. Excise leaf scar region.

2. Isolate DNA

3. Amplify DNA using internal trancribed spacer regions (ITS 4 & ITS 5) of rDNA followed by

clectrophoresis.

4. PCR product of -169 bp is observed.

Applied value of the technique

1. Help estimate the percentage of red rot infected canes. Thus, of significance in healthy

seed production.

2. Can detect the red rot pathogen in mixed infections.


- 106 -

Disease Free Seed Production of Cereals

M.K. Nautiyal Department of Gen. and Plant Breeding, BSPC, G.B.P.U.A.&T., Pantnagar-263145 (Uttarakhand)

Seed is a mature ovule consisting of an embryonic plant together with store of food

surrounded by a protective layer i.e. seed coat. Seed is the basic, vital and cheapest input of

agriculture. Use of quality seed results in 10-15 percent increase in agriculture productivity. It

should have uniformity, safe moisture content and high germination and vigour of seedling. It

should be perform diseases and insect pests.

Principles of Seed Production:

Production of good quality seed is the main objective of any seed production programme. It is known that the quality of seed deteriorates over a period of time after development due to several reasons namely: i) mechanical mixture, ii) natural out crossing iii) infection by disease causing organisms, iv) developmental variation, v) mutation, vi) minor genetic variations, and vii) instability due to segregation and cytogenetic causes. Seed production essentially follows a strict seed generation system from nucleus to breeder, breeder to foundation, foundation to certified and certified to truthfully labelled seed or commercial production. Nucleus and breeder seed production is monitored by breeder seed monitoring team, whereas foundation and certified seed production is supervised and certified by State Seed Certification Agency in the light of seed Act, 1966. In addition to the above kind of seeds, truthfully labelled seed is also produced without certification. However, the truthfully labelled seed must meet almost all the standards prescribed for certified seed.

Precautions in Seed Production

Raising of crop for seed purpose differ from growing crop for commercial purpose in

several respects. Precautions are required in seed production during crop production, harvesting,

processing, storage and marketing so that the desired quality of seed is produced and processed.

Important considerations in seed production are as follows:

1. Seed Source

Appropriate class or source of seed is used for production of desired kind of seed. For

example the nucleus seed is the source for breeder seed and breeder seed is source for

foundation seed and foundation seed is source for certified seed.

2. Selection of Land

Land to be used for seed production should be fertile, well drained and free of volunteer

plants. The field should not have the different varieties of same crop in previous season. Volunteer

plants are a very serious problem in Brassica species. Self-grown plants continue to appear for 3-4

years. Volunteer plants are also problem in legumes, pearl millet, and sorghum. When rice is

transplanted after puddling the soil, volunteer plants are rare.

3. Registration of Seed Crop for Certification

As per implementation of seed act 1966 and seed rules 1968 foundation and certified seed

production is registered with state Seed Certification Agency which certifies the seed production

and issues appropriate seed tags. The registration for seed production is done by the seed

producer with the concerned State Seed Certification Agency.


- 107 -

4. Seed Standards

In India standards for foundation and certified seeds have been prescribed. There are two

types of standards, i) field standards which apply to the standing crop, and ii) seed standards

which are applicable at seed level. Field standards includes requirement isolation distance,

maximum permissible level of off types, inseparable other plants, objectionable weed plants,

pollen shedders (in male-sterile or A lines), plants infected by seed borne disease etc. Seed

standards relate to genetic purity, physical purity, germination, other crop seeds, weed seeds,

moisture content etc.

Standards for breeder seed have not been prescribed but breeder seed has stricter

standards than those prescribed for foundation and certified seeds. Breeder seed must be 100%

genetically pure.

5. Isolation Distance for Seed Crop

Isolation is essential to avoid mechanical mixture during harvesting or collection of produce

and out crossing. In strictly self-pollinated crops it is mainly to avoid mechanical mixture from

adjoining plots. Isolation requirements in cereal crops like wheat and paddy is 3 meter.

Sources of contamination could be other varieties of the same crop, same variety not

conforming to varietal purity requirements of the category of seed under production, other crops

(mustard and turnip; maize and teosinte) or weeds. In wheat isolation requirement from other

varieties is only 3 m, whereas isolation from fields of wheat, triticale and rye of infection of loose

smut in excess of 0.1% and 0.5% is 150 m in case of foundation and certified seed.

6. Time of Sowing

Seed crops are generally sown at their planting time as recommended for commercial

crops. However, depending on incidence of diseases and pests, and monsoon, some adjustment

in sowing time could be made. Care should be taken that monsoon do not coincide with the

flowering, seed filling and seed maturity stage, especially with kharif crops.

7. Method of Sowing

The seed crop should be sown in lines with a seed drill/ planting equipment. One direction

sowing helps in cultural operations and inspection. Before and after sowing a variety, the seed drill

must be subjected to thorough cleaning of pipes, seed cups and box. The seed crop must be sown

in such a way that it facilitates the movement of the personnel to execute roguing effectively.

Skipping one row after every eight to ten rows or more may provide sufficient path for movement

during roguing in wheat seed crop. Similarly, paired row planting in rice, green gram and chickpea

is very useful. In crops like maize, pearl millet, sorghum, pigeon pea etc. the row to row spacing is

wide enough for the purpose of roguing.

8. Cultural Practices

Cultural practices such as seed bed preparation, fertilization, weeding, irrigation etc. are

usually the same for seed crop as recommended for commercial crop. All recommended


- 108 -

agronomic practices should be followed to provide conditions for optimal growth and development

of plant and seeds, which favour production of healthy and vigorous seed. Clean cultivation with

proper weed control during seed production makes subsequent cleaning and grading easier.

Phosphate and potassium fertilizers are generally more important for seed crops than for

commercial crops and their recommended doses must be applied.

9. Roguing

Roguing is the removal of Off-type plants. It is an important aspect of seed production to

maintain varietal purity. Any plant which does not conform to the characteristics of the variety is

called an Off-type. Off-types are generally considered to arise from segregation of residual

heterozygosity, out-crossing with varieties, admixtures or natural mutations. Off-types could be

distinct from plants of variety with reference to any character such as plant height, days to

flowering, waxiness, pigmentation, ear shape, ear size, ear density, ear colour etc. It is essential

that Off-types are removed before they flower, particularly in cross-pollinated crops, to avoid

contamination by pollen from Off-type plants. Roguing may need to be carried out several times

during the crop season. Composite, synthetic and open pollinated varieties of cross-pollinated

crops generally have broad genetic base and some amount of variability is inevitable. Roguing in

such varieties should not be very rigid so that the varietal gene pool is not disturbed. Only obvious

Off-types and diseased plants etc. should be removed.

In addition to roguing, all plants that do not conform to the varietal descriptors, inseparable

other crops plants, objectionable weeds as well as plants infected with seed-borne diseases

should also be removed. As a general rule, the Off-types should be removed and taken away from

the seed production plot and destroyed. The back of the person doing roguing should face sun to

facilitates easier detection of Off-types.

In hybrid seed production, some additional operations may be required such as

detasselling in the seed parent rows in maize and removal of pollen shedders from the male-sterile

rows in pearls millet, sorghum, sunflower and rice. During flowering period, pollen shedders must

be removed daily early in the morning before they shed pollen. Certain special techniques like

spraying of GA3 and rope pulling are required in hybrid rice seed production. Supplementary

pollination in hybrid seed production of sunflower by putting beehives in close proximity of seed

crop ensure good seed set.

10. Inspection of Seed Plots by Certification Agency Officials

The production of foundation and certified seed is supervised and approved by the State

Seed Certification Agency. The seed production plots are inspected by the certification staff. The

number of inspections vary from a minimum of 2-4. Those plots which conform to field standards

of certification are approved. Breeder seed has been kept out of the purview of certification agency

as it is not meant for public sale. Moreover, its production is done under the direct supervision of

qualified plant breeder. However, breeder seed crop is monitored by a joint inspection team of

plant breeders and officials of State Seed Certification Agency and National Seeds Corporation.

11. Harvesting

After the seed field is approved for field standards, seed crop should be harvested at a time

that will ensure maximum yield and best quality seed. The moisture content is good indicator of the


- 109 -

time to harvest for most seed crops. From stand point of minimizing the seed damage due to

mechanical harvesting safe moisture content for wheat is 15-17%, paddy 17-20%, soybean 13-

15% and maize 25-30%. The thresher, combine harvester should be properly adjusted so as to

avoid damage to the seed.

In hybrid seed production where two parents are involved the male parent rows are harvested

first and removed from the field. The whole field is then inspected to see any broken or lodged male

plants which are to be removed before harvesting of female parent rows for hybrid seed.

The thresher, combines, trailers, threshing floors etc. must be thoroughly cleaned in

handling of different varieties to avoid any mechanical admixture.

12. Post Harvest Handling

a) Seed Drying: Seed crop is harvested and threshed usually at high moisture content. In order

to preserve seed viability and vigour it is necessary to dry the seed to a safe moisture content

for storage and processing. Care should be taken to dry the seed quickly through natural

drying (sun drying) or through artificial drying (using solar dryer/ fuel dryer). Ensure that no

mechanical admixture take place during drying.

b) Storage of Raw Seed: After proper drying, the raw seed is filled in new/ neat and clean gunny

bags with proper marking of name of variety, plot, lot number etc. The raw seed is stored for

short period before processing in a seed grader machine. The stacks of bags should be kept

on wooden racks away from side walls. The height of stacks should not be more than 3-4

meter in case of case of cereals, and 2-3 meters in case of other crops. The godown for seed

storage should be dry, cool, clean and sprayed with insecticide (Nuvan/ Deltamethrin) and

fumigated, if necessary.

c) Processing, Testing and Labelling of Seed: Seed is processed in seed processing/ grading

machines for removal of physical impurities, over size/ under size seeds and treatment with proper

fungicide/ seed treatment chemical. After processing, the sample of seed lot is sent to the notified

seed testing laboratory for analysis and verification of seed standards. If the seed test report is

satisfactory and seed meets the prescribed seed standards then the seed lot is approved and the

tags and certificate are issued by the Seed Certification Agency to the seed producer. The validity

period for seed standards (especially germination) is 9 months (6 months for soybean). Validity

period can be extended to further six months provided the seed lot meets the prescribed standards

on retesting. Each class of seed will have of different colour tags which is to be stitched properly on

sealed seed bags. The colour and size of tags are as follows:

Breeder Seed : Golden yellow (12 x 6 cm)

Foundation Seed : White (15 x 7.5 cm)

Certified Seed : Blue (Azure blue) (15 x 7.5 cm)

Truthfully labelled seed : Opel green (15 x 7.5 cm)

Seed Certification standards for Different Crops (at Field Level)

Crop Numbers of Plants/ ear heads per count

Isolation distance (in Meter )

% of other variety

plants/ ear heads

% of

inseparable

plants/ear

heads

Objectionable

weed plants

Plants/ear

affected by seed

borne disease

Minimum

inspection

required

Remarks

F.S. C.S. F.S. C.S. F.S. C.S. F.S. C.S. F.S. C.S.


- 110 -

1 2 3 4 5 6 7 8 9 10 11 12 13 14

Wheat 1000 3 3 0.05 0.2 0.01

barley,

oat,

gram,

triticale

0.05

barley,

oat,

gram,

triticale

& & 0.10 0.50 Three

inspections

vegetative

flowering

maturity

Distance

from

loose

smut

affected

crop

(150m)

Paddy 1000 3 3 0.05 0.2 & & 0.01

Wild

Rice

0.02

Wild

Rice

& & - do - &

Hybrid

Paddy

1000 200 100 0.05*

0.05

Female

0.05

Male

0.10*

0.2

0.2

& & 0.01

Wild

Rice

0.02

Wild

Rice

& & Four

inspections

vegetative

flowering

maturity

Pollen

shedder

s in

female

parent

Maize

Composite

100 400 200 1.00 1.00 & & & & & & Three

inspections

vegetative

flowering

maturity

Hybrid

Maize

100 200 Same

grain

colour 300

different

grain

colour

& 1% Female

0.05% Male

2.00% in all

three

inspections

& & & & & & & Five

inspections

vegetative

flowering

maturity

5% or

more

plants

should

have

receptive

silk

Sorghum 1000 200

400

Johnson

grass and

fodder

sorghum

100

400

Johnson

grass and

fodder

sorghum

0.05 0.10 & & & & 0-05 0.10

Grainsmts

handsmats

Three

inspections

vegetative

flowering

maturity

&

Pearl

Millet

100 400 200 0.05 0.10 & & & & 0.05

0.02

0.05

green pod

0.04 argot

0.01

Candula

Three

Inspections

vegetative

flowering

maturity

&

Hybrid

Pearl

Millet

100 1000 200 0.05

Female*

0.05

Female

0.05

Male

0.10*

0.10

Female

01.0

Male

& & & & & & Five

inspections

vegetative

flowering

maturity

Pollen

shedders

in female

parent


- 111 -

Seed Certification Standard (Standard (in %))

Foundation class: F.S., Certified class: C.S.

Crop Pure seed (minimum)

Inert matter (maximum)`

Other crops seed

(maximum)

Total weed seed

(maximum)

Objectionable weed

seed

O.D.V. Germination

Moisture

Simple container

Vapour proof

container F.S. C.S. F.S. C.S. F.S. C.S. F.S. C.S. F.S. C.S. F.S. C.S. F.S. C.S. F.S. C.S. F.S. C.S.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19

(A) Cereals

Wheat 98 98 2 2 10/kg 20/kg 10/kg 20/kg 2/kg 5/kg & & 85 85 12 12 8 8

Paddy 98 98 2 2 10/kg 20/kg 10/kg 20/kg 2/kg 5/kg 10/kg 20/kg 80 80 13 13 8 8

Barley 98 98 2 2 10/kg 20/kg 10/kg 20/kg & & 10/kg 20/kg 85 85 12 12 8 8

(B) Millets

Maize (inbreads)

98 98 2 2 5/kg & & & & & 5/kg & 80 & 12 & 8 &

Maize (hybrid)

& 98 & 2 & 10/kg & & & & & 10/kg & 90 & 12 & 8

Maize (compost)

98 98 2 2 5/kg 10/kg & & & & 10/kg 20/kg 90 90 12 12 8 8

Open pollinated

Pearl millet (variety and hybrid)

98 98 2 2 10/kg 20/kg 10/kg 20/kg & & & & 75 75 12 12 8 8

Sorghum 98 98 2 2 5/kg 10/kg 5/kg 10/kg & & 10/kg 20/kg 75 75 12 12 8 8

Millets (commn, finger, ittelian, kodo, little and barnyard)

97 97 3 3 10/kg 20/kg 10/kg 20/kg & & & & 75 75 12 12 8 8


- 112 -

Seed Health Management for Better Productivity in Pulses

H.S. Tripathi Department of Plant Pathology, G.B.P.U.A.&T., Pantnagar-263145 (Uttarakhand)

Chickpea (Cicer arietinum L.) is an important grain legume in the Indian sub-continent,

West Asia, Northern and Eastern Africa, and Central and South America. Mainly two types of

chickpea are grown, brown seeded called "Desi", and white seeded called "Kabuli". Movement of

seeds of germplasm and breeding materials from one location to another is important in any crop

improvement progamme. However, with the movement of seeds there is a danger of introduction

of new pathogen (s) or pathotype (s) in new areas. So far 33 fungal, 1 bacterial and 7 viral

diseases have been reported on chickpea from different parts of the world (Nene, 1980). Some are

of economic importance; these are Fusarium wilt (Fusarium oxysporum f. sp. ciceri), dry root rot

(Rhizoctonia bataticola), black root rot (Fusarium solani), collar rot (Sclerotium rolfsii), and wet root

rot (R. solani). Among the leaf diseases, Ascochyta blight is considered most important. Other leaf

diseases like Botrytis grey mould (Botrytis cinerea), Colletotrichum and Alternaria blights have also

been reported serious in some years.

Of the several diseases recorded on chickpea very few are reported as seed-borne. The

seed-borne nature of Ascochyta rabiei was described by Luthra and Bedi (1932) and subsequently

confirmed by Maden et al (1975). Howare et al (1978) described the seed-borne nature of F.

oxysporum f. sp. ciceri. During 1979-80, 1980-81, and 1981-82 crop seasons, production of

chickpea in Northern India and Pakistan suffered heavy losses due to Ascochyta blight and

Botrytis grey mould. These diseases have the potential of devastating the crop, particularly when

the humidity and temperatures are high. There is some evidence that the sudden outbreak of

these diseases in the commercial fields was partly due to infected seeds.

Pulse growers can minimize losses from these diseases by using high quality seed. Seed

testing is required to establish whether or not seed is infected .Seed health tests are currently

available to detect all the important seed-borne pathogens of pulses. Only seed that is pathogen-

free should be used for sowing. Testing seed before sowing will identify potential disease

problems and allow steps to be taken to reduce the disease risk. Laboratory testing is usually

required as infected seed may have no visible disease symptoms.

Importance of seed- borne diseases

Uncontrolled movement of infected seed between regions can also result in the rapid

expansion of the area affected by these diseases. Pathogens can adversely affect germination

and cause seedling infection or damage to mature plants. The transmission of fungal and bacterial

pathogens, from seed to crop can vary considerably depending on growing conditions. Diseases

caused by viruses usually have higher transmission rates than those caused by fungi and bacteria

and are less affected by seasonal conditions. Consequently, there are different tolerance levels for

seed infection for different pathogens. Seed - borne diseases often strike early in the growth of a


- 113 -

plant and cause poor crop establishment and reduced plant vigor which results in lower yields.

Most seed borne diseases cause reduced yields e.g. Cucumber mosaic virus in lupines. However,

some diseases can cause total crop loss e.g. ascochyta in chickpea.

Preventing seed borne diseases

It will be best to sow pathogen-free seed. Testing seed before sowing will establish

whether or not seed is free of disease. The next best option is to select seed from crops which

show no sign of disease. Seed with high levels of seed- borne disease should not be used for

sowing .For some fungal diseases it may be possible to reduce the risk of disease by applying a

fungicide to seed prior to sowing. However, seed treatments are not available for the control of

virus or bacterial diseases.

Seed production

Crop hygiene is important in the production of pathogen-free seed. Avoid contamination of

clean seed. Harvest disease-free crops first. Seed can be contaminated during harvesting or

following harvesting if the equipment being used is contaminated. Infected seed may sometimes

be smaller, shriveled or discoulored. Cleaning and grading seed may reduce the proportion of

diseased seed (small or shriveled).Colour sorting may sometimes be used to remove seed that is

affected by disease and discoloured.

Extent of transmission from seed to crop (epidemiological rates)

Development of seed-borne disease is dependent primarily on three factors: (1) the

amount of seed-borne inoculum, (2) the extent of transmission of this inoculum to the seedling

(seed plant transmission), and (3) the rate of increase of disease in the field.

Crop losses are likely to be higher for pathogens that invade the roots soon after

germination (and there is little chance of escape), than for pathogens that affect the shoots of

young plants. The extent of 'seed plant transmission' of fungal and bacterial pathogens is known to

vary considerably depending on infection conditions. Poor germination and diseased seedlings

can result from the use of infected seed lots.

Epidemiology

Transmission from seed to seedling is usually highest for viruses and varies from around

0.1-5% for AMV and CMV, up to 100% for PSBMV. Transmission rates for fungal and bacterial

pathogens are affected more by the environment and some diseases can also be carried over in

soil and/or on crop residues. There is a wide range of tolerance levels for different pathogens. For

viral diseases a threshold of <0.1% seed infection is recommended for sowing in high risk areas,

and <0.5% seed infection for sowing in low risk areas. For most fungal pathogens a threshold of

<1% seed infection is acceptable. However, there is a nil tolerance for the most serious fungal

diseases e.g. Ascochyta rabiei in chickpea.

Measuring seed- borne inoculum

The amount of inoculum may be expressed in terms of the proportion of infected seeds, the

degree or severity of infection (inoculum per individual seed) or the viability of the inoculum (i.e.


- 114 -

the infectivity of the pathogen in seed). Most seed tests measure the proportion of infected seed.

Because low levels of seed- borne inoculum can lead to considerable disease, the most sensitive

test should be used to determine the level of seed infection.

Fungi may be detected using a standard blotter test or an agar plate test, the latter being the more

sensitive. Seed-borne bacteria can also be detected using an agar plate test. Seeds are often

surface sterilized with Na O Cl before testing to eliminate other saprophytic fungi, although this pre

treatment can reduce the percentage recovery of the pathogens where infections are not deep

seated. Results of these standard tests indicate the proportion of infected seed they provide no

information on the amount of inoculum per seed. Where a high percentage of seed is infected

there is often more inoculum per seed associated with larger infections and deeper penetration.

Seed-borne viruses are usually detected using ELISA or PCR tests. It is important that the

diagnostic tests are conducted on germinated seed (seedlings) as virus may sometimes infect the

seed test a without infect in the embryo or seedling e.g. PSBMV.

Survival on seed

Seed borne pathogens can often survive for several years in and on seed. Pathogens are

not always carried on the seed coat but can be harboured deep inside seeds. Fungi and bacteria

are mostly located in the seed coat, and embryo infection is uncommon. Infestation levels of most

pathogens decrease rapidly during storage and long-term storage can eliminate some pathogens

from seed. Unfortunately, there is likely to be a marked reduction in the viability of seed stored for

a long period and this may negate any benefits from lowering disease levels in seed. Viruses are

not carried on the seed coat and are only found in the seed embryo or tissues of the seed coat.

Infection of seed

Most fungal and bacterial diseases are favoured by wet conditions and seed produced

under warm, humid conditions usually becomes heavily infected while seed produced in drier

regions is often free of infection. Seed infection levels are determined primarily by weather

conditions between flowering and maturity and warm, humid conditions during this period often

result in heavy pod and seed infection. Dry weather between flowering and maturity minimizes pod

infection and is essential for the production of pathogen free seed. There is often considerable

variation between genotypes in their resistance to seed infection.

Virus infection in seed depends on the amount of spread of virus between plants during the

growing season, often by aphid vectors, and the genetic susceptibility of the host plant.

Important seed borne diseases

Viruses

Alfalfa Mosaic Virus (AMV)

Plants may develop a bright yellow leaf mottle, tip necrosis, stunting, pod flattening and

blackening. Yields are reduced through plant death, the production of small seeds, and seeds with

brown coat discolouration.

Cucumber Mosaic Virus (CMV)


- 115 -

Plants may develop leaf chlorosis (yellowing), stunting, distortion or bunchy appearance

and pods may be flattened and turn purple-brown.

Pea Seedborne Mosaic Virus (PSBMV)

Plants may develop downward rolling of leaf margins and slight clearing of the veins in

young leaves. Production of small seeds with distinctive brown staining and 'tennis ball' marking is

common. Seed discolouration can significantly reduce the commercial value of grain.

Bean Yellow Mosaic Virus (BYMV)

Plant leaves may develop leaf mottle or a distinctive yellow mosaic pattern, stunting and

reduced leaf size. Early infections can seriously reduce plant growth and grain yield.

Bacteria

Bacterial blight (Pseudomonas syringae pv pisi and Pseudomonas syringae pv syringae)

Important seed borne disease of field peas. Both these pathogens may be carried by the

seed either internally or externally. Water-soaked leaf, stem and pod lesions may occur at any

growth stage. Yields are reduced through plant death, crop damage and the production of small

seeds. Brown discolouration of the seed coat can sometimes occur.

Fungi

Grey mould and chocolate spot (Botrytis cinerea and Botrytis fabae)

Stem infection can cause the damping-off of young seedlings. Later infection causes grey mould

or chocolate spot on foliage and flowers. Yields are reduced through plant death, crop damage

and flower abortion. Infected seed can be small and badly discoloured.

Ascochyta blight (Ascochyta fabae, Ascochyta lentis, Ascochyta pisi, Ascochyta rabiei,

Mycosphaerella pinodes Phoma pinodella)

Tan coloured lesions form on leaves, stems and pods. Infected leaves may drop

prematurely. Yields are reduced through plant death and crop damage. Infected seed can be

shriveled or badly stained.

Lupin anthracnose (Colletotrichum lupini)

Bending and twisting of stems with a lesion in the crook of the bend. Stem infection often

results in the death of plants and major yield losses. Affects both narrow leaf lupins and albus

lupins.

Phomopsis stem blight (Phomopsis leptostromiformis)

Causes yellow-brown lesions on leaves stems and pods. Severe infection can kill plants.

Infected seed can be covered with a web-like grey mould. Toxin produced by infected stubble can

kill animals.

Brown leaf spot (Plieochaeta setosa)

Can cause both root rot and leaf spotting. Affected roots develop large dark brown lesions.

Irregularly shaped dark brown lesions develop on infected leaves. Can seriously reduce plant

growth and grain yield.

REFERENCES


- 116 -

1. Agarwal, V.K. (1981). Seed-borne fungi and viruses of some important crops. Research Bulletin

108. Directorate of Experiment Station G.B. Pant Univ. of Agril. & Tech. Pantnagar.

2. Haware, M.P., and Y.L. Nene, and R. Rejeshwari (1978). Eradication of Fusarium oxysprorum f. sp. ciceri transmitted in chickpea seed. Phytopathology 68: 1364-1367.

3. Haware M.P., Y.L. Nene and S.B. Mathur (1986). Seed-borne diseases of chickpea. Technical bulletin from the Danish Government institute of seed pathology for developing countries. copenhagen, denmark No. 1. In collaboration with international crops research institute for the semi-arid tropics (ICRISAT)

4. Luthra, J.C., and k.S. Bedi Bedi (1932). Some preliminary studies on gram blight with reference to its cause and mode of perennation. Indian Journal of agricultural Science 2: 499-512.

5. Maden, S., D. Singh, S.B. Mathur, abd P. Neergaard (1975). Detection and location of seed- borne inoculum of Ascochyta rabiei and its transmission in chickpea (Cicer arietinum). Seed Science and Technology 3: 667-681.

6. Nene, Y. L. (1980). A World List of Pigeonpea (Cajanus cajan (L.) Millsp.) and Chickpea (Cicer arietinum L.) Pathogens. ICRISAT Pulse Pathology Progress Report no. 8: 1-14.

7. Nene, Y. L. (1972). A Survey of Viral Diseases of Pulse crops in Uttar Pradesh. Research Bulletin No. 4 Directorate of Experiment Station G.B. Pant Univ. of Agril. & Tech. Pantnagar.


- 117 -

Role of Cultural Practices on the Management of Seed Borne Diseases

R.P. Awasthi Department of Plant Pathology, G.B.P.U.A.&T., Pantnagar-263145 (Uttarakhand)

The life cycle of a plant begins with the introduction of seed germination in soil and

ultimately ends up with the seed production. During different stages of life cycle, a seed passes

through many stages of growth from germination and emergence of a tender seedling to profuse

vegetable growth, and subsequently, bearing flowers, fruits and ultimately the seed. During

different stages of plant, growth, the plant interacts with number of pathogens/ microorganisms.

At different seed development stages of plant, commencing from flowering to seed

maturation, a number of microorganisms including viruses may enter and establish a pathogenic

relationship within the seed tissue. Once the seed is infected, it may serve as a carrier of the

pathogen or as a consequence of infection; the seed itself may be victimized or killed.

The microorganism such as fungi, bacteria and nematodes including viruses may be borne

in the seed or carried on the surface of the seed or may be admixtured with the seed during

harvesting or threshing processes. What so ever may be the location of infection in seed, the

mechanism of seed infection is very much influenced by the environmental conditions during seed/

crop development stages.

Many different types of control methods aim at eradicating or reducing the amount of pathogen

present in an area, a plant, or plant parts (such as seeds). Many such methods are cultural, that is,

they depend primarily on certain actions of growers, such as host eradication, crop rotation, sanitation,

improving plant growing conditions, creating conditions unfavourable to pathogens, polythene

mulching, trickle irrigation, ecofallow, and, sometimes reduced tillage farming.

Selection of seed production areas

Seed should be produced in areas where the pathogens of major concerns are unable to

establish or maintain themselves at critical levels during period of seed development. Area with

low rainfall and low relative humidity generally are favourable for production of high quality seeds

with low inoculum levels. Moderately cool climate, with dry summers, is ideal for production of high

quality cabbage seeds relatively free of Xanthmonas campestris pv. campestris and Leptospheria

maculans. Area with low rainfall during boll opening of cotton is best for cottonseed production as

there is reduced infection by Alternaria alternata, Diplodia gossypina, Fusarium oxysporum, F.

roseum, Glomerella gossypii and Nigrospora sphaerica.

Selection of high quality seeds

Planting seeds should be free of the pathogen as possible. Seed should come from a

carefully maintained, generally pure block and should be in selected production fields. They should

be cleaned commercially and treated chemically or non- chemically.

Seeding Rate


- 118 -

The seeding rate should not be excessive. A high seeding rate can increase the number of

focuses of primary infection that may develop in the field which ultimately can result in higher

disease incidence and seed infection.

Planting Time

Plant at a time when requirements of the host and pathogen do not correspond and thus

the plant may escape infection. Winter wheat sown early in autumn may escape infection from

Tilletia caries and T. foetida because plants pass the susceptible stage before bunt spore

germinate. Crops sown later may get infected. Planting oat seeds in early spring reduces the

incidence of Ustilago avenae. Adjusting planting of soybean such that it matures at the end of the

rainy season reduces the amount of seedborne Colletotrichum truncatum. In this case although

the seed yield is lower than those producing during the rainy season, seed quality is superior.

Balanced Fertility

Adequate, balanced soil fertility, coupled with near neutral pH, is important in reducing

seed infection. Plants under stress from deficient or toxic levels of nutrients are more susceptible

to disease than those grown in soil with well balanced fertility. Insufficient phosphorus or potash in

soybean can increase losses from bacterial blight, bacterial pustules, charcoal rot, pod and stem

blight, soybean cyst nematode, and several root and stem decaying pathogens. An excessive

application of fertilizer may result in a greater disease incidence.

The incidence of seedborne Alternaria padwickii in rice increases proportionally to increase

nitrogen from 0 to 200kg/ ha. Above 100kg/ ha, the incidence of Curvularia lunata, Phoma sp. and

Trichothecium sp. increases compared to 0 and 50kg/ ha.

Planting Method

Planting method is effective in reducing seed transmission of TMV in tomato. A low transmission

was obtained in direct planting (5%) as compared to transplanting (71%). Sowing wheat on the surface

of recently flooded land results in a low incidence of flag smut (0.08 to 0.2%): in plots irrigated after

sowing at 4cm deep, a moderate incidence results (2.4 to 3.2%), and in soil moist enough for ploughing

there is a high incidence (8.1 to 8.6%). Rice seeded in water is less infested with the nematode

Aphelenchoides besseyi than that drilled in and flooded when 6 to 9 cm high. Quiescent nematodes

probably revive in water, move about, and die in the water before seed emergence.

Spacing

Reduced spacing between plants favour seed borne infections. Close spacing results in

high humidity among plantswhich can be conducive for heavy seedborne infections. At 15 cm

between rice plants , therer was a higher percentage of seedborne Alternaria alternata, A.

longissima, A. padwickii, Curvularia lunata, Drechslera oryzae, Fusarium semitectum, and

Sclerotium sp. than at wider distances. Soybean seeds from narrow- row (25 cm) compared to


- 119 -

wide- row (76 cm) spacing gives higher recovery of total fungi and bacteria which adversely affect

the quality of clean seeds.

Depth of Planting

Depth of planting greatly influences seed transmission of smuts. Shallow planting in soils

protects wheat plants from Urocystis tritici (flag smut) in wheat.

Water Management

Water management practices influences disease development. Irrigation can be tuned to

reduce stress. Water management strategies vary depending upon growing areas, most common

diseases, soil types, etc. Irrigation especially at the seed development stage, may favour seed

infection. Irrigation time and amount of water should be controlled so that the relative humidity is

not raised to such an extent that it becomes conducive for seed infection. Overhead irrigation

should be avoided where possible.

Crop Rotation

Crop rotation and play an important role in controlling seedborne pathogens because many

important bacterial and fungal pathogens survive between crops in or on crop debris. Rotating

soybean with a non-host crop every second year is effective for reducing most foliage and stem

pathogens, and a rotation every third year for soil borne pathogens.

Isolation Distances

The distance between seed production and commercial plots has been worked out for

reducing seedborne loose smut of barley and wheat. The distance between plots may vary from

region to region depending on weather conditions. Barley and wheat crops should be isolated by

at least 50 m from any source of loose smut infection for production of certified seeds.

Rouging

Rouging should be practiced where possible. In seed production fields, infected plants

should be rouged and destroyed. Rouging has been followed successfully in the control of loose

smut of barley and wheat.

Tillage

Tillage has a significant influence on the abiotic and biotic soil environment. Under zero

tillage soil water content, penetration, and retention are increased and erosion decreased as

compared with conventional tillage practices such as ploughing. Soil temperatures generally

decrease as more crop residue is left on the soil surface. Direct tillage results in changes to the

soil moisture and temperature, which in turn impacts the biological activity of soil microflora and

fauna. The changes effected by direct tillage may favour some pathogens while limiting growth of

others. Conservation tillage can have a beneficial influence on other soil properties including: soil

crusting, bulk density, drainage, and porosity. Soil organic matter and soil microbial activity may

also be enhanced under conservation tillage. Changing tillage practices can alter the ecosystem in

the field due to changes in natural enemies, microenvironment and crop residues.

Conclusion


- 120 -

Innumerable studies and practical experience show that adoption of individual, even

exceptionally effective plant protection measures cannot ensure long term suppression of a

number of harmful organisms. This can be achieved only by systemic, coordinated application of

all the available prophylactic and destructive measures. The judicious use of different methods of

pest control can play a significant role in combating pest problems in the system. The

implementation of such a strategy would be really viable in case its components are well worked

out. Among all components, the agronomic practices play a vital role in mitigating disease

problems as it involves no expenditure and is free from all ill- effects. This unique method of

control can serve as a backbone of any sustainable system of pest management. Furthermore, the

modifications in agronomic practices can be blended with any available technique such as

biological control, resistant varieties etc. without adversely affecting the environment.

REFERENCES

1. Bockus, W.W. and Shroyer. 1998. The impact of reduced tillage on soilborne plant pathogens. Annu. Rev. Phytopathol. 36: 485-500.

2. Prew, R.D., Ashby, J.E., Bacon, E.T.G., Christian, D.G., Gutteridge, R.J., Jenkyn, J.F., Powell, W., and Todd, A.D. 1995. Effects of incorporating or burning straw, and of different cultivation systems, on winter wheat grown on two soil types, 1985-91. J. Agric. Sci. Cambridge 124: 173-194

3. Windels, C.E., and Wiersma, J.V. 1992. Incidence of Bipolaris and Fusarium on subcrown internodes of spring barley and wheat grown in continuous conservation tillage. Phytopathology 82:699-705.


- 121 -

Smuts, Bunts and Ergots their Significance and Management in Seed Crop

R.C. Sharma

Seed Technology Centre, Punjab Agriculture University, Ludhiana Smuts, Bunts and Ergot are important seed borne diseases, the primary inoculum of which

is carried in or on seed (smuts and bunts) or go as an admixture (ergot) with the seed.

Smuts and Bunts

The word smut means a soft, charcoal-like substance or a sooty powder. The organisms

causing smuts and bunts belong to order Ustilaginales. The resting spores, commonly known as

smut spores are thick-walled and on germination produce septate or aseptate promycelium

bearing basidiospores (called sporidia) laterally and apically or in groups at the apex of the

promycelium. Sporidia are haploid and when they germinate, a haploid mycelium (primary

mycelium) is produced which later gets dikaryotic. This mycelium invades the host plant, usually

keeps pace with the meristematic region of the host.

Types of infections in Smuts

The infection by the smuts fungi may be primary or secondary, systemic or local,

depending upon the species in question. On the basis of primary infection the following three types

may be remembered for better control of these diseases:

1. Seedling infection: The smut spores are usually smooth-walled, externally seed- borne,

and germinate along with the germinating seed to cause seedling infection. The infection of

seedling takes place before its emergence out of the soil. Change of haplophase to

diplophase occurs before infection (Flag smut and covered smuts).

2. Floral or blossom infection or Intra-seminal Infection: The spores are usually rough-

walled and wind-borne to fresh flowers where they germinate to cause infection of the

ovary after diplodization. The binucleate hyphae reach the embryo, ramify, and become

dormant with maturity of the seed. The infection is thus carried internally with the seed and

when the latter germinates the fungus also grows up and finally appears as black powdery

mass in the inflorescence (Loose smut diseases).

3. Shoot Infection: This is usually localized infection. The spores may fall on the surface of

the host, germinate, and cause infection of young buds, young flowers, developing seeds,

or may fall on the ground, perennate there ultimately germinating next year causing

infection of the host parts through wind-borne sporidia (Karnal bunt of wheat and Kernel

smut of rice).


- 122 -

Ustilaginales

_______________________________________________________

Cup-shaped No basidiocarp formed

basidiocarp _____________________________

present

Promycelium septate, Promycelium septate,

basidiospores produced basidiospores formed

laterally from each cell apically in a cluster

of the promycelium

Ustilaginaceae Tilletiaceae

(Smuts) (Bunts)

Ustilago sagetum tritici Tilletia foetida

U. hordei

U. avenae T. caries

U. kolleri Neovassia horrida

U. scitaminea

U. maydis N. indica

Tolyposporium penicillariae

Sphacelotheca sorghi

S. reiliana

Various smut diseases caused on different hosts are described as below

Loose smut of Wheat (Ustilago sagetum tritici)

Loose smut occurs more seriously in humid areas than in dry areas. In India, the disease is

more prevalent in northern parts resulting in 3-4 % crop losses however some individual fields may

show up to 20 % smutted heads. The disease is characterized by the presence of black smut

spores in place of grains which later are blown away by wind leaving behind the bare rachis. As

the pathogen is internally seed borne (embryo infection), seed treatment is the most effective

control measure including hot water treatment, solar treatment and seed dressing with systemic

fungicides viz vitavax (2 g/kg), bavistin 2.0-2.5g/kg and raxil 1g/kg. The tolerance levels in the

field for loose smut of wheat are fixed at 0.1 and 0.5 % for foundation and certified seed,

respectively. The isolation distance is of 150 m.

Flag smut of wheat (Urocystis agropyri)

The disease has been appearing and causing significant losses since 1848 in Australia

from where it is believed to be introduced into India and spread to various wheat growing areas.

The disease was observed to be in severe from in 1964-65 in Rajasthan and in 1971 in Kullu (HP).

Usually up to 10% loss has been common due to this disease. The leaves of infected plants

become twisted and assume a dropping habit, and the plant remains sterile bearing no grains.

Grayish black bands running parallel to veins (having smut spores) also appear on older leaves.


- 123 -

The disease perpetuates through seed and soil, so same seed treatment as for loose smut is

effective. To avoid soil inoculum, shallow sowing is recommended. Sowing in acidic or sandy soils

should be discouraged, as in such soils, the disease incidence is more.

Karnal Bunt of Wheat (Neovossia indica)

The disease causes 5-20 % losses in some wheat cultivars but annual yield loss of 0.2-0.3

% of total production has been reported from Punjab. The disease initially being reported from

India (Karnal) has now assumed international significance because of enforcement of quarantine

by more than 20 countries. The disease has been reported from J&K, HP, UP, MP, WB, Haryana

and Rajasthan. Though the disease does not cause significant yield losses, it is responsible for

deterioration of quality. Infected seeds also show significant reduction in seed germination and

vigor. As the disease is initiated by air borne sporidia at the time of flowering, seed treatment is of

no value and hence different strategies viz. crop rotation late sowing, avoiding use of excessive

nitrogen and irrigation, foliar sprays (propiconazole and tebuconazole) have been recommended.

The tolerance levels for karnal bunt of wheat are fixed at 0.05 and 0.25 % for foundation and

certified seed, respectively.

Hill Bunt of Wheat (Tilletia caries and T. foetida)

Hill bunt causes about 10-20 % yield losses, being restricted to northern hilly areas,

however sporadic appearance in plains have been reported which might be due to use of

contaminated seed from hills. The infected ear-heads remain green for a longer period and emit a

foul smell due to presence of trimethylamine which is characteristic feature of the disease. Being

seed borne the disease can be effectively controlled by the seed treatment with the same

chemicals as used for loose smut of wheat.

Covered smut (Ustilago hordei) and loose smut (U. nuda) of Barley

Covered smut of barley is more common than loose smut and has been reported from

northern parts of India, causing considerable losses on susceptible varieties. Infection of both the

smuts leads to the production of black mass of smut spores in place of grains. However the spore

mass is covered by a persistent membrane (epidermis) in covered smut, the thin membrane

covering the spores in loose smut ruptures during emergence, and a bare rachis is left after the

dispersal of spores. Mode of infection in case of covered smut is through seedling while loose

smut fungi enter through florets. Loose smut being internally seed borne and covered smut being

externally seed borne, seed treatment as in case of loose smut of wheat has been the effective

and economical. Hot water treatment has also been recommended against loose smut of barley.

Covered smut (U. kolleri) and loose smut (U. avenae) of Oats

Oats suffer from both the smuts, which are worldwide in occurrence. Usually, the two

diseases occur simultaneously in the same field. Often the covered smut is more common than the


- 124 -

loose smut. The smut spores being formed in place of grains get blown away by wind as the thin

membrane ruptures leaving behind the bare rachis in loose smut, while the inflorescence tend to

retain its shape in case of covered smut infection due to presence of persistent membrane

(epidermis) covering the smut spores. Loose smut and covered smut being internally and

externally seed borne respectively can be best managed by seed treatment with different

chemicals as used for loose smut of wheat.

Rice Leaf Smut (Entyloma oryzae)

The disease initially reported from India and Burma is now known to occur in Japan,

Taiwan; Philippines, Afghanistan Venezuela, USA and China. However, the disease is not

economically much important. The disease is characterized by distinct lead black colored spores

linear, rectangular or angular in shape, and covered by epidermis which ruptures only when the

leaves are soaked in water. As disease perpetuates through hypophyllous sori lying in the field in

diseased leaf trash, it can be controlled by following clean cultivation practices.

Paddy Bunt (Neovossia horrida or Tilletia barclayana)

Paddy bunt initially being reported from Japan has now spread to almost all rice growing

areas in India and abroad in Uttar Pradesh, the loss has been estimated up to 3.2 per cent. The

disease has become a major bottleneck in hybrid seed production. Because of localized air borne

infection all ears in a stool and all grains in a ear are not affected. Usually the sori are hidden by

glumes but sometimes glumes are forced apart giving a appearance of minute black pustules or

streaks as a feature of disease. As the disease is initiated by air borne sporidia produced from

tetiospores lying in the soil at the time of flowering, seed treatment is not so effective, however

foliar sprays of the same chemicals as used for karnal bunt of wheat are recommended at

flowering stage. Cultural practices like crop rotation, field sanitation etc. help in reducing inoculum.

Usually early sowing varieties escape infection of florets by air borne sporidia The tolerance levels

for kernel smut of rice are fixed at 0.1 and 0.5 % for foundation and certified seed, respectively..

Smut of Sugarcane (U. scitaminea)

The disease has been reported from all sugarcane growing areas of the world except Australia.

In India, it is more serious in tropical regions (Maharashtra, Andhra Pradesh, Karnataka, and Kerala)

causing both cane yield and quality losses. The disease is characterized by the formation of whip like

structure having black smut spores arising from the central axis of plant. The affected canes become

slender and thin. As the disease perpetuates through smut spores present on infected canes/cane

sets or ratooned canes, the disease can be managed by following cultural practices like removal of

smutted whips, avoiding preparation of plant sets from smutted canes, discouraging the practice of

ratooning, along with disinfection of sets before planting with Agallol (0.25% suspension), mercuric


- 125 -

chloride (0.1%) formalin (1.0%), Bordeaux mixture (4:4:50), vitavax, benlate, bavistin. Hot water

treatment (55-60°C for 10 min) has also being recommended against smut.

Common Smut of Maize (U. maydis)

Common smut of maize is of minor importance, being confined to Kashmir; less common in

Punjab and rarely noticed in North Western parts of UP. The disease is distinct because of its

effect on maize which is not common among smut fungi and results in to formation of galls.

Infection of female flowers gives rise to galls while stem galls result in bending of stalk. The

membrane (epidermis) covering the galls later ruptures, exposing the black spore mass. Being soil

borne, the disease can be reduced drastically by following crop rotation, field sanitation and seed

treatment.

Head Smut of Maize (U. reiliana)

Head smut has been found moderately destructive in Sub-temperate Himalayas and hilly

areas of Rajasthan, while a minor incidence has also been reported from TN, Andhra Pradesh, UP

and Punjab. The whole tassel is converted in to a large sac having smut spores with floral bracts

growing in to leafy structures. Columella is not formed. Disease is soil borne so crop rotation,

sanitation and seed treatment is effective in reducing soil inoculum. The tolerance levels in the

field for head smut of sorghum are fixed at 0.05 and 0.1 % for foundation and certified seed,

respectively.

Grain Smut of Sorghum (Sphacelotheca sorghi)

Grain Smut despite being known to cause huge losses in different countries (US Myanmar,

S. Africa, Italy) has been reported to be a destructive disease causing up to 25 % grain losses in

India. The disease results in to formation of oval dirty gray sori having black smut spores and

central hard column called Columella composed of host tissues. Infection of plant occurs at

seedling stage and hence the disease can be controlled by solar heat treatment, treatment with

Formalin (0.5% for 2 hrs), Copper Sulphate Solution (0.5-3.0 % for 15 min). The tolerance levels in

the field for grain smut of sorghum are fixed at 0.05 and 0.1 % for foundation and certified seed,

respectively.

Loose Smut of Sorghum (S. cruenta)

In India it is prevalent in Andhra Pradesh, Bombay, Karnataka and TN causing not only

grain damage but also affects plant growth and hence fodder yield. The smutr spores produced in

place of grains get exposed duer yto rupturing of membrane. Columella is formed and persists

even after dispersal of spores. The management practices followed against grain smut also takes

care of loose smut in sorghum.

Head Smut of Sorghum (S. reiliana)


- 126 -

Head smut is prevalent as a minor disease in T.N, UP, MP, Karnataka, Bombay and

Punjab. Instead of each individual grain, the whole inflorescence is converted in to a long spore

sac. The smut spores are covered by a membrane which breaks easily during emergence of ear.

Columella is not formed. As the disease is predominantly soil borne, sanitation crop rotation and

seed treatment help in greatly reducing the disease. The tolerance levels in the field for head smut

of sorghum are fixed at 0.05 and 0.1 % for foundation and certified seed, respectively.

Long Smut of Sorghum (Tolyposporium ehrenbergi)

This smut has wide occurrence through out the world (West Africa, Egypt, Iran, Pakistan).

In India it has been reported from TN, Maharashtra, Karnataka, MP, UP. Each individual gain is

converted in to smut sori. The infected grains are usually surrounded by healthy grains. Columella

is not formed. Infection being air borne-seed treatment is of less use. Early sowing helps in

escaping infection of flowers. Crop rotation and field sanitation help in reducing the production of

air borne sporidia from soil inhabiting smut spores.

Smut of Bajra (Tolyposporium penicillariae)

Smut of Bajra is a important disease in India as well as other countries causing a yield loss

of 5-20% which may be higher under favorable conditions. The disease has been reported to be

more severe on CMS based single cross hybrids than open pollinated varieties. The smut sori

formed in this disease are pear or oval shaped larger than the size of grain and are projecting

clearly beyond the glumes. These sori have black smut spores covered by tough membrane

composed of host tissues. The disease perpetuates through soil borne smut spores germinate and

produce sporidia at the time of flowering. These sporidia become air borne and cause floret

infection. As a result of air borne infection, seed treatment is not so effective. The control practices

involve removal of smutted ears use of clean seed, hot weather deep ploughing, field sanitation

and crop rotation. The tolerance levels for smut of bajra are fixed at 0.05 and 0.1 % for foundation

and certified seed, respectively.

False smut of rice

The pathogens (Ustilaginoidea) appears almost in all rice growing states in India and other

countries causing considerable grain losses.The pathogen was first described under the name of

Ustilago virens but later classified under Ascomycetes as it closely related to claviceps. The

effects of the parasite are visible only on the grains. Due to development of the fructifications of

the pathogen, scattered individual grains are transformed into large, velvety, green masses,

sometimes more than twice the diameter of the normal grains. Inside the mass the colour is

orange yellow on the periphery and nearly white in the centre. The fungus perennates through the

hard soporiferous masses which become sclerotia. The infection of ovaries takes place through


- 127 -

conidia at an early stage. The disease can be managed by developing resistant varieties,

fungicidal foliar sprays and use of sclerotia free seeds (through steeping or processing).

Ergot Diseases

The fungi causing ergot diseases belong to order Sphaeriales of class pyrenomycetes

(Subdivision: Ascomycotina). The fungus has been named so because of formation of hard, dark

colored compact fungal structures called sclerotia or ergot on infected parts of plants. The ergot

diseases have been reported on many graminaceous plants viz. rye, oats, barley, wheat, pearl

millet sugarcane, however ergot of bajra is more common. The disease had occurred in

epiphytotic form in 1956 at South Satara area of Maharashtra and since then, it has become a

major limiting factor in the cultivation of improved bajra hybrid varieties. Average incidence of

disease has been observed up to 62.4% causing a grain loss of about 58% under favorable

conditions. Presence of toxic alkaloids in the ergot adds to the importance of disease causing

nuisance to both animals as well as human beings. Infection is evident from blossoming to

maturity. Initially disease manifests as a conidial honeydew stage on inflorescence with masses of

conidia exuded in sugary suspension. Later in the season, the infected kernels get transformed in

to black horny structures called ergots. Various management practices include destruction of

collateral hosts (C. ciliaris and P. antidotales), early sowing of crop to escape high temperature at

flowering, use of sclerotium free seed and spray of protective fungicides at flowering (Ziram Cu-

oxychloride). The tolerance levels for ergot of bajra are fixed at 0.02 and 0.04 % for foundation and

certified seed, respectively.


- 128 -

Ear Rot and Banded Leaf & Sheath Blight of Maize

S.C. Saxena Department of Plant Pathology, G.B.P.U.A.&T., Pantnagar-263145 (Uttarakhand)

Banded leaf and sheath blight of maize caused by Hypochonus sasakii is one of the most

widespread and destructive disease of maize due to its wide host range and adaptability in south east

Asian countries. The disease manifest on leaves, leaf sheaths, stalks lesions or rind spotting resulting

in stem breakage, clumping and cracking of styles and ear rot etc. resulting in cent per cent grain

damage and lodging of plants in severe conditions

Pantnagar is one of the hot spot for this disease and the studies are being carried out at this

location for last 25 years on epidemiology, pathogen variability and disease management using

chemicals, cultural practices, bio-control agents including evaluation of maize genotype for resistance

sources.

Studies carried out with respect to chemicals only Tilt (Propocanozole) showed some

effectiveness. Cultural practices do not fit in normal recommended technology of maize production.

Use of bio-control agents opens up a new era for management. But in this case use of T. harzianum a

common bio-agent exhibited synergistic effect on ear rot development. Few newer bio-agents are

under experimental stage. An another new chemical Divident 3 WS (Diphenoconazole) is being also

tested. Few inbred lines/genotypes have also been identified which are under confirmation for use in

resistant breeding programme. A set of experiment is also in execution for use of integrated approach

to manage the banded leaf and sheath blight to success.

Introduction

Maize ( Zea mays L. ) is the third most important cereal crop in the world agricultural economy

as food for man and feed for livestock. The total area under maize cultivation in the world is about

127.38 m.ha with a total production of 470.5 m tonnes with the average yield of 3694 kg/ha.

About 112 diseases of maize have been reported so far from different parts of the world, of these 65 are known to occur in India. The major diseases in different agro-climatic regions are, seed rots and seedling blight, leaf spots and blights, downy mildews, stalk rots, banded leaf & sheath blight, smuts & rots leading to about 15-20 percent yield losses annually.

Pantnagar, being the hot- spot for a number of diseases. At present it has been the main

centre for maize pathology research for 3 major diseases among which, Banded leaf and sheath blight

(BLSB) is the most important one. This diseases is known under many names, viz.,sclerotial

disease, banded sheath rot, banded sclerotial disease, sharp eye spot., oriental leaf and blight,

Rhizoctonia ear rot, leaf & sheath blight, sheath blight, sheath rot and corn sheath blight.

The disease is caused by Rhizoctonia solanni = Hypochonus sasakii (Thanatephorus cucumeris

(frank) Donk). It is one of the most widespread, destructive and versatile pathogen. It is found in

most parts of the world and is capable of attacking a wide range of host plants including maize

causing seed decay, damping-off, stem canker, root rot, aerial blight and seed/ cob decay. It is


- 129 -

due to combination of its competitive saprophytic ability and high pathogenic potential that makes

H. sasakii a persistent and destructive plant pathogen.(Saxena, 1997).

Economic losses

The disease was earlier reported as a minor disease on maize (Payak and Renfro 1966).

The importance of the disease was only realized in early 1970s when an epidemic occurred in

warm and humid foot hill areas, in the Mandi district of Himachal Pradesh. The disease results in

the direct loss exhibiting premature death, stalk breakage and ear rot. Losses to the extent of 11-

40 per cent were reported while evaluating 10 different varieties of maize.

Losses in grain yield showed a high positive correlation with premature death of plants and

disease index that caused drastic reduction in grain yield to the tune of 97 per cent. A direct

correlation with other yield parameters exibited.in a yield loss of 5 to 97.4 per cent at disease

score levels ranging from 3.0 to 5.0.

Host Range

The pathogen has wide host range and infects plant belonging to over 32 families in 188

genera. H. sasakii infects by artificial inoculations a number of crop plants belonging to families

Graminae, Papilionacae and Solanaceae : Paspalum scrobiculatum, Pannisetum purpureem,

Setaria italica, Panicum miliaceum, Coix lachryma –jobi, Echnochola fromentacea, Pennisetum

americanum, Zea maxicana Zea mays, Oryza sativa, Saccharum officinarum Sorghum bicolor,

Arachis hypogea, Glycine max, Pisum sativum, Vigna radiata and Lycopersicum esculentum. Rice

and maize isolates are, however, indistinguishable on the basis of cross inoculation tests, host

range, virulence, number of nuclei per hyphal cell, and other morphological characters including

pathogenicity. Comparison studies of rice maize, sugarcane and sorghum isolates revealed that

maize and rice are similar than those isolates of sugarcane and sorghum.

Symptoms

The symptoms of the Banded leaf & sheath blight are observed on all aerial parts of the

maize plant except tassel. The disease manifests itself on leaf, leaf sheaths, stalks and ears as

leaf & sheath blight, stalk lesions or rind spotting and stalk breakage, clumping and cracking of

styles (silk fibre), horse-shoe shaped lesions with banding of caryopses, ear rots, etc. Under

natural conditions, disease appears at pre- flowering stage on 30 to 40 day-old plants but infection

can also occur on young plants which may subsequently result in severe blighting and death of

apical region of growing plants.

On Leaves

Under natural conditions, dropping blades especially the distal halves of leaves proximate

to soil surface are affected. Infection spreads from leaf shealths to the basal portion of leaves.

Lesions appear as in irregular patches, similar in colour but larger in size and spread more rapidly

than on leaf sheath, covering greater areas with alternating dark bands.

On Leaf Sheaths

The symptoms are more common on sheaths than on leaves. The disease appears on

basal leaf sheaths as water soaked, straw colored, irregular to roundish spots on both the


- 130 -

surfaces. A short of wave pattern of disease advancement can be seen not only on leaves but

also on sheaths and husk leaves. In early stages marginal chlorosis and rotting of laminae

proceed inwardly. Later as the infection becomes older numerous sclerotial bodies are also seen.

On Stalk

The pathogen also causes elongated dark brown to black spots of lesions on the rind of the

stalk under the affected sheaths. These spots coalesce together extending the lesions and

covering almost an internode. Individual lesion range in size from 2-10 x 3-15 mm to those which

cover the whole internodes. Some times these lesions are transformed into cankers and a few

girdle near the nodes. Under artificial inoculation entire rind is some times affected, the stalk

thereby weakened and breaks easily.

On Ears

The disease observed first of all, on basal part of the outermost husk leaves forwarding to

sheath from which the ear emerge. The same types of lesions are found on ear but the bands are

fairly prominent, giving a blackened appearance. The affected ears become brown and numerous

sclerotia are observed on husks, lightly attached to the cob. Whitish mycelium and sclerotia are also

seen frequently on silks between and on kernel rows and glumes.

The grain showed light greyish to dark brown discoloration, drastically reduced in size and wrinkled,

and under severe conditions, the grain became chuffy and light in weight.

Inoculum Preparation

A pathogenic isolate of R. solani obtained from fresh diseased leaf sheath of maize was

used throughout the investigations. For preparation of large scale inoculum, sorghum grains were

soaked in water for 24 hours and after thorough washing in running tap water, the soaked grains

40-g were filled in 250 ml Erlenmeyer flask after removing excess water. These flasks were tightly

plugged with non-absorbent cotton and aluminum foil. Grain filled flasks were then autoclaved

twice at 151b psi for 30 minutes. The second sterilization was repeated after 24 h of first one.

Each flask was shaken to remove formation of grain clots. This grain medium was used for

inoculation with actively growing culture of R. solani in PDA plates. One or two discs were seeded

in each flask and then the flasks were incubated at 28+ 1 0C for 7-10 days. During incubation, the

grains in flasks were also shaken to provide uniform fungal growth on all grains. These grains

were then used for artificial inoculation in field experiments wherever required.

Artificial Inoculation Technique:

Field inoculations were carried out by inserting two sorghum grains between the leaf

sheath and stem on lower third/fourth internode above the ground level just before the tassel

emergence stage of the crop. The inoculations were repeated after 3 days of first inoculation to

safeguard the plants against the escapes. Observations on the BLSB disease were recorded two

weeks after flowering following 1-5 disease scale where 1.0 = No infection; 2.0= Partial infection

upto lower four leaf sheaths and leaves; 3.0 = Heavy infection upto lower four leaf sheath and

leaves, partial on upper leaf sheaths below the ear placement, no cob infection, 4.0 = Heavy


- 131 -

infection on all leaf sheaths and leaves below the ear placement partial infection on cobs, 5.0 =

very little or no grain formation, grain become chuffy or cob may be rotten.

Chemical Control

The experiment was planned using 18 fungicides in three replications following randomized

block design. The plot size was kept 5 x 3 m2 with 4 rows at 75 cm apart. All the plants were

artificially inoculated at 40th and 50th day of planting followed by foliar sprays of fungicides after 3

days of inoculation. The observation on disease severity, 1000-grain weight, grain yield per ha

and cobs/plant were recorded and analyzed statistically. Only thiobendazole was found most

effective followed by Duter & Vitavax in reducing the disease severity and resulting in higher grain

yield while in following year only 10 fungicides were included based on the performance in

previous year testing. Of these vitavax (carboxin), TPTH (Triphenyl tin hydroxide) and

thiobendazole were found to be most effective.

During last few years, some newer chemicals which are claimed to be effective against

sheath blight disease were also tested under different sets of experiments. The chemicals viz.,

Propaconazole, 0.1% (Tilt) & carbendazin, 0.05% (Savistin or Bavistin) were tried following

different methodology.Both the chemicals were applied as foliar sprays at 30, 40 and 50th day of

planting alone or in combinations of application. The experiments were planted in three

replications following Randomized Block Design. The plot size was 7.5 m2 with 2 rows of 75 cm

apart. Artificial inoculations were carried out after 40th day of planting and repeated after 2 days of

first one. The chemicals were applied as per treatment and the data on disease severity and yield

parameters were recorded and analyzed statistically. The result indicated that the effectiveness of

Propaconazole was markedly observed when the chemical was applied at initial stages at 30th or

40th day of planting and the second spray at 10 days after first. Foliar sprays of Carbendazim

showed the ineffectiveness against BLSB as well as on the yield parameters.

Visualizing the efforts on chemical control which were not so effective from practical

application point of view, the other approaches for disease management were also included in the

studies.

Biological Control

Bio-control agents Trichoderma harzianum, Gliocladium virens, Pseudomonas sp. were

tried alone or in combination with propaconazole and carbendazim along with a cultural control

treatment with common check. All the methodology was the same as discussed in previous

experiments.

None of the treatment effectively reduced the disease but foliar sprays of T. harzianum +

Tilt followed by T. harzianum sprays, Saivistin + Tilt + T. harzianum, Savistin + Tilt and Savistin

alone could exhibit some reduction in disease levels. Cultural practice, removal of lower leaves

alone was not be so effective and would not be practicable to the farmers. While evaluating the

biocontrol bacteria against R. solani, the fluorescent Pseudomonas could not reduce the BLSB.


- 132 -

Subsequently in nature, it had been observed that the pathogen H. sasakii, when infects

cob shank and husk, the T. harzianum also parasitizes the fungus. The mycoparasitism by

Trichodioma leads to a synergistic action in increasing the cob rot and grain infection. To find out

the synergistic action of both the fungi, an experiment was planned following randomized block

design and three replication in field under artificial inoculation of the organism alone or in

combinations which indicated that the present of R. solani followed by the infection of Trichoderma

was more harmful that is what happening in nature also.

Disease Resistance

Different genotypes received from various sources since 1975 were evaluated under All

India Coordinated Research Project on Maize at Pantnagar using artificial inoculation techniques.

Following genotypes are grouped as resistant/moderately resistant.

CM-103, CM-104, CM-105, CM-211,CM-117,CM-118-1, CM-118-2, CM-200,CM-201, CM-

202, CM-205, CM-300, CM-500, CM-600, Eto 182, Aust 25, P217, P 407, CML- 267, Antigua

Gr.II, JML-32, JML-306, JML-403, VL-43, CM 107 x CM 108, RN6Ht1 A x GE 440.


- 133 -

Aflatoxin in Maize

S.C. Saxena Department of Plant Pathology, G.B.P.U.A.&T., Pantnagar-263145 (Uttarakhand)

Fungal contamination of agricultural crops has plagued farmers since the beginning of

agriculture.

Aflatoxin Discovery

The current epoch of fungal research in food/feed safety emerged as a result of an

outbreak of disease in turkeys in England in 1960. Fortunately, the English penchant for thorough

and detailed explanations initiated a search for the causative agent of the disease; this effort was

the beginning of a new area of agricultural research that has been labeled mycotoxicology. Initial

histological examination of tissues from the diseased birds demonstrated an acute hepatic

necrosis associated with bile-duct proliferation. Examination of bird rations showed that a common

factor in disease outbreaks was the use of a Brazilian peanut meal. Subsequent tests showed the

common occurrence of fungal isolates associated with the Aspergillus flavus group. Two closely

related species, A. flavus and A. parasiticus, have since been identified as the toxin-producing

species.

Four closely related compounds were characterized and were generically named aflatoxins

B1 and B2 G1 and G2 (B= blue fluorescence; G= green fluorescence). A. flavus to produce

exclusively B1 and B2, whereas A. parasiticus exhibited the capacity to produce all four toxins.

Plant Pathology/mycotoxicology

To explain the differences between parasites and saprophytes broadly grouped into two

biotrophy or parasitism (deriving nutrients living material and necrotrophy or saprotrophy (deriving

nutrient from non living material). Obligate saprotrophy and obligate or facultative necrotrophy.

Numerous mycotoxin-producing fungi can be saprophytic, but they also occur in living tissues and

are difined as facultative necrotrophs, i.e., species that are usually saprotrophic, but which can

also function as parasites.

Aflatoxin in Postharvest Maize Storage fungi

The development of storage fungi in a post harvest commodity is determined by a number

of factors, such as availability of inoculum, physical integrity of seed, moisture, temperature,

aeration and nature of the substrate. Among the variables, moisture is clearly a dominant factor.

Storage fungi, principally Aspergillus and Pencillium spp. are commonly found in maize stores at

13 to 18% moisture. The A. glaucus group predominates at 13 to 15% moisture, but above 15%

other microbes appear, including the toxin-producing species A. flavus, A. ochraceus and A.

versicolor. It has been reported that A. flavus did not invade starchy grains below 17.5% moisture.

In response to observations relating moisture levels to fungal growth, the US Department of

Agriculture (USDA) assumed a very conservative position, describing drying techniques for control


- 134 -

of mycotoxins in post harvest maize and recommending reduction of moisture to 13% within 24

hours after harvest.

Storage fungi water requirements

In defined media, an optimum (available water) of 0.91 to 0.99 has been observed for

growth of A. flavus and A. parasiticus . Although an aw. of 0.87 did not dramatically reduce fungal

growth, however the aflatoxin production was restricted.

The moisture requirements in intact seeds clearly differ from submerged fermentations. In

mature maize kernels, A. flavus does not routinely exhibit extensive growth below an aw of 0.85.

However, at slightly higher levels (aw/0.87), the fungus grows and produces aflatoxin. A. number

of microbial species have been identified as effective competitors with the aflatoxin-production

strains. For example, A. niger, A. oryzae and R. nigricanes can effectively reduce development of

A. flavus and A. parasiticus.

Moisture in stored maize

Although A. flavus appears to require at least 17.5% moisture for development on a starchy

grain, the moisture distribution within a stored lot is critical. Moisture retention in high-moisture

grain relative to drier grain has been attributed to hysteresis. High moisture (27 to 28%) and low-

moisture (10%) maize blends that have mean moisture levels of 14% or less will support A. flavus

development and aflatoxin production.

Temperature effect on storage fungi

In conjunction with moisture, temperature plays an important role in the development of

storage fungi. Generally, fungi grow readily between 200 and 600C, with a restrictive range of 00 to

600C optimum 360 - 380C, but ranges from 60 to 460C. In laboratory media, maximum aflatoxin

production has been observed at 250C, with no toxin biosynthesis below 7.50C or above 400C.

Other factors affecting storage fungi

The microbial profile of a freshly harvested crop influences subsequent competitive

interactions. Damaged grain provides an opportunity for a fungus to circumvent the natural

protection of the integuments and establish infection sites in the vulnerable interior. Aeration can

also be a particularly critical factor for storage microbes since fungi are aerobic. Reduced oxygen

or increased carbon dioxide levels reduce fungal activity and toxin production. Evidences are

available for a relationship between genetically transmitted traits in kernel pericarp thickness and

susceptibility to fungal infection; and some other genetically mediated differences in stored maize

kernels to invasion by storage fungi.

Confirmation of aflatoxin contamination in preharvest maize

Kernels inoculated between two weeks after flowering to maturity yielded aflatoxin with little

effect from insecticide treatment. Visual observations of maize at various locations in the USA

identified the presence of bright greenish-yellow fluorescence (BGYF) on preharvest kernels in

Georgia. The fluorescence had initially been observed in cotton fibers in association with A. flavus

development. Investigation of the origin of BGY-fluorescence material demonstrated that it was not


- 135 -

aflatoxin but a derivative of kojic acid, another relatively unique fungal metabolite. Bright greenish-

yellow fluorescence in maize kernels was adapted as a presumptive test for presence of fungi in

the A. flavus group.

Sixty ears from each of 60 fields in a four-country area of southeastern Missouri, 600 ears

from two Missouri field and 750 ears from five fields in southern Illinois were collected. Mycological

studies of kernels demonstrated an average A. flavus incidence of about 5%, with elevated

occurrence in kernels from insect damaged ears. Although earlier reports had identified the

presence of A. flavus in preharvest maize, the 5% incidence exceeded prior observations.

Morphological tests identified elevated occurrence of A. flavus relative to A. parasiticus in kernels

and insects. After shelling, drying and cracking, 237 samples of the 3600 ears in the general

survey and 12 of 1350 ears in the intensive study exhibited BGY fluorescence. Aflatoxin tests

showed that 120/3600 in the general survey and 6/1350 in the intensive study contained aflatoxin

levels exceeding 20 ppb.

A number of facts concerning the preharvest contamination process had been established as

below:

Yellow and white maize were equivalent in susceptibility to fungal infection;

A positive relationship was obwerved between BGY-fluorescing particles and presence of

aflatoxin;

Aflatoxin contamination varied both intra-and inter regional;

Aspergillus flavus predominated in aflatoxin-contaminated maize kernels and associated

insects;

Kernel damage by insects increased the potential for aflatoxin accumulation;

Intensive insecticide application reduced but did not eliminate preharvest toxin production;

Aspergillus flavus infection occurred from two weeks after flowering to physiological

maturity, with maximum infection in the late-milk to early-dough stage (20 days post-

flowering);

Variation in timing of maize maturation appeared to be linked to contamination;

Stress factors during crop development seemed to incrase susceptibility; and

Genotypic determinants, such as enhanced husk development, were linked to reduced

preharvest aflatoxin contamination.

Preharvest moisture

Moisture was a major factor among many that affected the contamination process.

Although the xerotolerance of A. flavus provided and opportunity for competitive development at

moistures between 17 and 22%, it was apparent that the fungus was infecting kernels at 50%

moisture and above. To examine the moisture-related factors of preharvest toxin contamination,

an interregional study was carried out in maize grown in Illinois, Missouri and Georgia. The results

demonstrated that early aflatoxin contamination occurred in three diverse environments, but

moisture levels did not appear to independently exert a controlling influence in the process.


- 136 -

Preharvest temperatures

In the field, moisture and temperature are obviously confounded, since elevated

temperatures increase poant development rates, evaporation and water utilization. Although

laboratory temperature studies have identified A. flavus as a mesophile, it does not exhibit any of

the properties of an authentic thermophile.

Ability of A. flavus to grow on degreening silks and to infect kernels directly without insect activity.

These observations have made an important contribution to understanding the breadth of

metabolic capabilities of A. flavus. However, there appear to be some relatively strict limitations on

A. flavus substrate requirements. Broad natural occurrence of aflatoxin in US markets has only

been observed in maize, cottonseed, peanuts, grain sorghum, millet, copra, tree nuts and figs.

Absence of aflatoxin in freshly harvested soybeans presents an intellectual challege to

mycotoxicologists. Since soybean are grown in the southern USA in close proximity to aflatoxin-

contaminated maize, absence of inoculum can not explain the inability of the fungus to establish a

toxin-producing presence.

Information gathered on preharvest aflatoxin contamination has since been modified by

several observations:

Characterization of definite association between elevated temperature during kernel

development and increased aflatoxin accumulation;

Elucidation of a mechanism for kernel infection by A. flavus without insect activity and toxin

contamination of intact kernels;

Identification of A. flavus resistance factors in inbred lines that reflect variations based on

the inoculation method;

Characterization of a direct correlation between water stress in developing maize and

susceptibility to A. flavus infection and toxin contamination;

Summary

Scientists gathered under the banner of mycotoxicology have shared unique experiences

during eh past 15 years. They have participated in the evolution of a new discipline. Creating a

new area of inquiry can be controversial and the study of toxic fungal metabolites is no exception.

The fundamental dilemma in mycotoxicology is its multidisciplinary nature; the scope and the

diversity of professional interests make it difficult to establish a single discipline. The work

inherently requires the expertise of microbiologists, plant pathologists, plant physiologists,

veterinarians, entomologists, mycologists, agronomists, plant breeders, soil scientists,

toxicologists, immunologists, oncologists, biochemists, chemists, public health scientists,

epidemiologists, climatologists and nutritionists. In mycotoxicology the dialogue among

practitioners has often resulted in recognizing common research interests and continuously

learning new skills.


- 137 -

Sampling and Detection Techniques for Aflatoxin in Maize

The objectives of sampling maize (Zea mays L.) for aflatoxin analyses may be to check for

the presence, distribution or concentration of aflatoxin in a given lot or among a population of lots.

The method of sampling should be appropriately designed. To check for the presence of aflatoxin

or to determine the incidence of aflatoxin among different lots, the sampling procedure should be

biased towards the inclusion of kernels that are more likely to contain aflatoxin.

The aflatoxin concentration in a lot of maize is usually estimated from a sample drawn from

the lot. A previous study has demonstrated that replicated aflatoxin tests on the same lot of shelled

maize may be highly variable. Because the toxin concentration in individual kernels of a lot may

range from 0 to over 500,000 g/kg (12,19), a large sample of kernels is required to insure that the

sample concentration is in reasonable agreement with the lot concentration.

Using Bright Greenish-Yellow Fluorescence to Detect Aflatoxin Contamination

A bright greenis-yellow fluorescence (GBYF) under longwave (365nm) ultraviolet light has

been associated with the presence of aflatoxin in maize, cottonseed and pistachio nuts.

Aflatoxin contamination of food and feed is important in human and animal health, because

the aflatoxins are toxic and carcinogenic. The toxic and carcinogenic properties of the aflatoxins

make experimental safety a very important issue in all work with aflatoxins or the fungi. Aspergillus

flavus and A. parasiticus that produce aflatoxins.

Biological safety

Spores and other viable propagules of A. flavus A. parasiticus and other fungi can cause

three types of disease in humans: allergy, poisoning and infection. Airborne spores and dust

containing propagules of the A. flavus group may cause allergies in some people and the inhaled

particles may contain aflatoxins. Two thinlayer chromatographic (TLC) methods have been

developed to measure aflatoxins in maize and grain dust. A. flavus infection in humans is

uncommon but possible.

Aflatoxin Testing Methods Presumptive and screening methods

Quantitative methods

Thin-layer chromatography

High-performance liquid chromatography

ELISA and RIA

Selection of Analytical Approach

Infection Process Colonization of external silks

They reported silk condition to be a better indicator of silk susceptibility than chronological

age since many factors influence the rate of silk senescence in the field. In a comparison of three

silk stages (green unpollinated, yellow-brown and brown) they found yellow-brown silks to be the

most susceptible. Silks at this stage have begun to senesce but are still succulent. In four to eight

hours, conidia of A. flavus germinated on these silks, first nearest the pollen grains. Then the

fungus spread rapidly across the silk, producing extensive growth and lateral branching. By 48


- 138 -

hours conidiophores and conidia were present on pollen grains. In contrast, few conidia

germinated on unpollinated silks by 24 hours and those that did failed to establish significant

mycelial growth. Brown silks also supported little growth of fungus, and growth was centrated

around pollen grains.

Aspergillus flavus penetrated yellow-brown silks both directly and indirectly through cracks

and intercellular gaps. Internal colonization of the silks was restricted to the parenchymatous

tissue, and growth was oriented parallel to the silk axis.

Internal silk and kernel colonization

Aspergillus flavus grows down silks very rapidly. In a controlled-environment chamber with

a 340C day and 300C night, a color mutant of A. flavus was recovered from the tip of the ear two

days after inoculation and from the base four days after inoculation. The fungus was found on the

glumes of the kernels and adjacent silks six days after inoculation, but not on the seed pericarp.

Growth of the fungus from incubated silk segments was first observed from the cut ends, indicating

that the fungus may move down the silks internally. Such directed growth down the silks could

explain the rapidity by which the fungus reaches the base of the ear.

Kernel infection

The colonization silks shortly after pollination and the rapid growth of A. flavus down the

silks suggest that the fungus may be following the same path as does the pollen tube, i.e., the

stylar canal. Such a route has been proposed for A. flavus.

Factors Influencing the Infection Process

Inoculum levels

Drought stress

Temperature


- 139 -

Production of Quality Seed in Tree Species

Salil Tewari Department of Genetics and Plant Breeding, G.B.P.U.A.&T., Pantnagar-263145 (Uttarakhand)

Nature has endowed India with vast forest wealth of great diversity, having from tropical

evergreen forests to dry alpine forests. There are about 15,000 species of flowering plants, the

woody vegetation constitute about 2,486 tree species of angiosperms (2,417 dicotyledons and 69

monocotyledons) and 21 gymnosperms. Increase in the pace of industrialization after

independence, coupled with a tremendous growth of human and livestock populations, placed

enormous pressure on forests, resulting in their depletion at a fast rate. Now there is a large gap in

demand and supply of the various forest products. The National Forest Policy, 1988, places great

emphasis on the maintenance of environmental stability through preservation of forests and

conserving natural heritage.

Tree improvement consists of a “marriage” of silviculture and tree parentage to obtain the

greatest overall returns. Tree improvement has an important role in Forest Management when

production of high volumes of good quality timber or non-timber forest products is the principal

management objective (Zobel and Talbert, 1984). Success in the establishment and productivity of

forest tree plantations is determined largely by the species used and the source of seed within

species. The most successful tree improvement programs are those in which proper seed sources

and provenances are used. Research has shown that if forests are to be of increased value

including the aspects of stability, adaptation, resistances, productivity and diversity, it is necessary

to use reproductive material, which is genetically and phenotypically suited to the site and is of

high quality. At present, most of the genetic material (seeds/planting stock material) used in

forestry sector in India is obtained from unspecified sources, from stands, natural or planted, which

are neither classified nor managed specifically for seed or planting stock material production.

A typical tree breeding programme primarily consists of selection of phenotypically superior

trees, utilizing desirable genes, mass multiplication of improved planting materials, and

maintaining a population with broad genetic base for advanced generation breeding. Detailed

knowledge of genetic principles, species biology, past history of selection, and the economic

importance of the trait to be improved is a prerequisite for implementation of such a dynamic

programme. All tree improvement programmes should have dual objective of (1) obtaining

immediate genetic gain in terms of better quality, wide adaptability and higher productivity and (2)

maintaining broad genetic base for continued improvement over many generations. Maximum

gains are achieved by the judicious use of a very few best parents (elite trees) to supply planting

stock in operational forestry programme. Following sections describe basic principles of plus tree

selection and their utilization.

India has been at the forefront since organized research in agroforestry started worldwide.

The All India Coordinated Research Project (AICRP) on Agroforestry with 20 centers all over


- 140 -

country was launched in 1983 to implement the major recommendations of the aforesaid seminar.

Further, National Research Centre for Agroforestry was established on 8th May in 1988 at Jhansi

to accelerate the basic, strategic and applied research in agroforestry. At present there are 36

centers under All India Coordinated Research Project on Agroforestry with project coordinating

unit at National Research Center for Agroforestry, Jhansi. These centers represent almost all the

agroclimates of the country. In addition to ICAR, Indian council of forestry research and education

(ICFRE) and its regional centres, private institutions and NGOs such as WIMCO, ITC, BAIF,

IFFDC, West Coast Paper Mills Ltd, Hindustan Paper Mills Ltd, National Tree Growers

Cooperatives are also engage in research and promotion of agroforestry in the country.

Agroforestry research and education has been started in more than ten State Agricultural

Universities (SAUs). More than 2000 scientists and technicians are engaged in agroforestry R&D

at present. The major thrust of agroforestry research in the beginning was mainly on the aspect

of, Diagnostic survey and appraisal of existing agroforestry practices, Collection and evaluation of

promising tree species/cultivars of fuel, fodder and small timber, and Studies on management

practices of agroforestry systems.

One of the major aspect of the research endevours under agroforestry was collection and

evaluation of promising tree species/cultivars of fuel, fodder and small timber. A lot of germplasm

has been collected and evaluated in arboretum established by different Centres of the project.

About 184 promising tree species have been determined based on growth performance trials at

these centers. The promising tree species identified include Ulmus wallichiana, Ailanthus excelsa,

Morus alba, Robina pseudoacacia and Grewia optiva for Western Himalayan region: Acacia

auriculiformis, Alnus nepalensis, Bamboos, Parasanthes falcataria and Gmelina arborea for

eastern Himalayan region; Poplar, Eucalyptus and Dalbergia sissoo for Indogangetic region:

Dalbergia sissoo, Acacia tortilis, A. nilotica, Ailanthus excelsa, Prosopis cineraria and Leucaena

leucocephala and Azadiracta indica for arid and semi arid regions; Albizzia spp. Erythrina,

Gliricidia, Acacia auriculiformis for humid and sub humid regions; and Casuarina equisetifolia,

Toona ciliata, Grevillea robusta for the coastal and island region. The efforts made so far has

created voluminous database, which is strength. The information collected may be utilized for

creating local and regional volume tables. However, the tree improvement work has not

progressed to the desired level except in case of two or three important species.

The most important input in any nursery is the genetically improved seed which will make

by far the most important contributions to the growth rates and quality of the timber produced.

Genetically improved seedlings or clonal planting stock supported with improved package of

practices can usher in a new revolution for vast improvements in productivity and quality of

plantation timbers. For example, clonal planting stock of poplars and eucalypts, being promoted by

some of the wood based industries on a limited scale supported with good technical extension

services, has improved productivity to an average of 25-30 m3/ha/year with very significant

improvements in the quality of timber (Lal et al., 2006). Very high productivity up to 50 m3/ha/year


- 141 -

has also been achieved by many farmers both in case of poplars and clonal eucalyptus

plantations.

Seed should either be procured only from most dependable and trust-worthy sources or

collected under personal supervision of user agencies. However unfortunately, even the State

Forest Departments and ICFRE institutions have not developed adequate sources for production

and supply of required quantities of genetically improved seed. Bulk of the seeds being used by

Forest Departments and private nurseries, even for most important timber species like teak

continues to be collected from unimproved seed sources of poor genetic quality. That is the main

reason for extremely low productivity of plantations in India.

The National Wasteland Development Board drawn an ambitious programme to

rehabilitate the 175 ha of Wasteland, requiring plantation of nearly 5 million ha land per annum.

However, lack of infrastructure and insufficient availability of seeds has limited the achievements

to 2 million ha per annum. The most essential factor for the success of the plantations is ready

availability of seeds, which is estimated to be more than 10,000 tonnes per annum for raising 2

million ha of plantations timber and other multipurpose species (Khullar et. al. 1991). The non-

availability of quality seed is a serious constraint in the way of realizing the above national target.

The seed being used in the current plantations programme is of poor quality in many respects,

such as low germination percentage, poor emergence in nursery beds and poor adaptability etc.

Because of poor quality the quantity of seed being used is much more than really required, thereby

increasing the investment on seed procurement enormously. So, there is need for a sound

national programme on production, testing, storage and supply of forestry seeds to ensure the

sustained supply of quality seeds and conservation of valuable germplasm. A brief account of the

collection, testing and storage of forestry seeds is presented with respect to the indigenous tree

species.

REFERENCES

1. Bisht, N.S. and Ahlawat S.P. 1999. Seed Technology, SFRI Information Bulletin no.-7. State Forest Research Institute. Itanagar, Arunachal Pradesh Pp, 1-23.

2. Hartmann, H.T. and Keskar D.E. 1983. Plant Propagation : Principles and Practices. Prentice-Hall of India Pvt. Ltd. New Delhi.

3. Martin, A.C. and Barkley W.D.1961. Seed Identification Mannual. Oxford and IBH Publishing Co. New Delhi.

4. Maithani, G.P., Bahuguna V.K. and Thapliyal R.C.1989. Preliminary Silvicultural techniques for planting of shrubs in the Siwaliks and Himalayas for rehabilitation of wastelands and degraded sites. The Indian Forester, 115 (1) : 3-10.

5. Schmidt, L. 1993. Seed Orchards. Guidelines on Establishment and Management Practices. Field Manual No. 4. RAS/91/004, UNDP/FAO, Philippines.

6. Toda, R. 1974. Forest Tree Breeding in the World. Yamatoya Ltd., Tokyo, Japan.

7. Zobel, B.J. and Talbert, J. 1984. Applied Forest Tree Improvement. Wiley & Sons, New York, USA


- 142 -

Management of Plant Propagating Material for Quality Control in Forest Crops

P.R. Rajput

Department of Agronomy, G.B.P.U.A.&T., Pantnagar-263145 (Uttarakhand) Civilization throughout the world is largely based upon man’s ability to propagate and grow

plants which can provide food, shelter, clothing aesthetic and other requirement. Plant propagation

has been a fundamental occupation since the time of Riguveda (1400 BC). Plant propagation aims

at the reproduction of selected individuals or group of individuals, in this basic principle of life

impose certain requirements which must be met with in practice for successful propagation

necessarily requires acknowledge of the science of structure, growth and function.

Plant propagation requires a perfect knowledge of scientific back ground of life process,

mechanical manipulation and technical skill to achieve desirable success. Plant reproduces by

means of sexual and asexual methods which are detailed here.

Propagation by Seeds

Propagation by seed which an end product of sexual reproduction in flowering plants is

very common in nature as well as adopted by man for most of annuals, biennials and perennials.

Some seeds germinate just after completion of their development while some seeds do not

germinate and pass through a period of rest i.e. dormancy. Dormant seeds need pregermination

treatment such as scarification, acid or hot water treatment.

Though propagation by seed is very common for field crops but it has certain limitations

with fruit trees, where number of seeds to be sown, production of fruits and their quality are of

paramount importance. Certified, nondormant vigorous and viable seeds are required to reproduce

a variety. Seedlings plants in number of cases are not true to the image of the parent. Seedlings

from cross fertilized seeds are generally heterozygous and produce plants which are not identical

to their parents on the contrary the homozygous seeds produce plants identical to their parents.

The vigour and other quantitative and qualitative characters can be achieved if plants are

subjected asexual methods of reproduction.

Forest tree species commonly propagated by seed

Acacia nilotica,

Adina cordifolia,

Dalbergia sissoo,

Erythrina blakei,

Pinus roxburghii,

Gmelina arborea,

Prosopis juliflora,

Toona ciliata, etc.


- 143 -

Advantage of propagation by seedlings

Seedlings are long lived, hardy and easier to propagate.

Only method of propagation where large scale vegetative propagation is not possible as in

the case of mangosteen, phals papaya etc.

The hybrids are first raised from seeds to develop a variety.

Polyembryonic seedlings raise plants true to the type. These may be used to raise

uniformaly identical plants.

Root-stock of plants propagated by seeds in usually hardy.

Disadvantages of propagation by seeds

Genetic variation occurs in seed from cross-pollinated plants

Some plants take a long time to grow from seed to maturity

Vegetative Propagation

Vegetative or asexual reproduction is based on the ability of plants to regenerate its parts

and tissues. Vegetative propagation is the formation of new independent plants from a part of the

parent tissue. Vegetative propagation ensures the production of exact copies of trees selected for

superior characters. Vegetative propagation can be achieved in several ways by involving

adventitious or dormant buds. The vegetative parts of plants are able to develop roots when they

are planted by different ways e.g. by coppice and root suckers, branch and stem cuttings, rhizome

cuttings in bamboos, root section cuttings and stump cuttings. Various horticultural techniques viz.,

layering, grafting, budding, tissue culture techniques, etc. are useful for propagation of some

species.

Advantages of Vegetative Propagation

A single stock can provide large number of plants.

Plants are genetically identical to parent plants and have similar growth and form

When trees are not producing seeds or if the seeds are not viable vegetative propagation methods

are quite useful. Plants take less time to develop therefore; it is normally easier and cheaper. It

helps to utilize maximum genetic gains in a shortest time. It helps to make investment in trees more

attractive by (a) increasing yield and quality and (b) shortening rotation.

Disadvantages of Vegetative Propagation

Only few species can be raised by this method. Many species do not root even in

controlled conditions. Even if they root the rooting is poor and unsatisfactory. The thickness, age,

etc. of cutting should be proper. Vegetative propagation is easier with young trees, but becomes

more difficult as trees age. The plant tissue culture techniques may be useful in propagating old

trees. The physiological and environmental factors play an important role in the propagation of

woody plants.

Methods of Vegetative Propagation

Macro-propagation and


- 144 -

Micro-propagation or tissue culture

Methods of Macropropagation of Forest Trees

Root suckers

Coppice

Cuttings

Layering

Grafting

Budding

Root Suckers

The shoots when arise from the roots are called root-suckers. The propagation by root-

suckers are obtained by felling the tree or injury to roots. In case of Dalbergia sissoo, D. latifolia,

etc. the root suckers originate at the cut ends. The species such as Acacia planifrons, A.

leucophloea, A. dealbata, and A. decurrens form root suckers freely whereas root suckers are

occasionally formed in Acacia nilotica and Acacia catechu when the roots are exposed.

Stereospermum and Millingtonia are able to produce natural root suckers at far away distances

from parent trees and without severance or root wounding. The root suckers can be promoted by

trenching around trees and running trenches through tree areas. This stimulates sprouting at the

cut ends. The shoots emerge out the buds developed on roots close to the ground surface. The

species preferred for obtaining root-suckers are : Populus spp., Diospyros melonoxylon, Dalbergia

sissoo, D. latifolia, Capparis aphylla, Platanus spp., Millingtonia hortensis, Nyctanthes arbor-tristis,

Phoenix humilis, Prunus padus, Robinia pseudoacacia, Salvadora oleoides, Azadirachta indica,

Aegle marmelos, Boswellia serrata, Garuga pinnata, Butea monosperma, Melia azedarach, Xylia

xylocarpa, and Zizyphus nummularaia, etc.

Coppice

New shoots are sprouted from the pollarded plants or from damaged buds. Sal, Teak and

Shisham coppice well. Conifers do not coppice but chir pine coppices in very young stage.

Coppice growth is quite vulnerable to high winds, rains and floods because the sprouts shear off

easily at the point of attachment to old tree growth. Coppice shoots have fast growth because of

food supply left in the stump and root system. Seedling coppice can be carried out every year for

some species for the desired purpose if original shoot is injured. Sal and Eucalyptus are the best

examples of seedlings coppice. There are nearly more than hundred species which coppice but

their coppicing power differs and for some species coppicing power depends on the size of tree

and availability of light. In teak plantation coppice shoots are tall and vigorous and can be easily

distinguished from planted trees. Only one dominating shoot should be retained from the coppice.

The coppice stumps cut from saw are always dressed along the periphery by an axe well before

rainy season.

Cuttings


- 145 -

It is the cheapest and best method of multiplying the stock. Many plants are propagated by

stem and root cuttings. Generally poplars and willows show good response. Any portion viz., stem,

root or branch can be taken as cutting. The cuttings can be of soft wood, hard wood or semi-hard

wood depending upon species and lignin content.

i.) Rhizome Cuttings

A piece of bamboo rhizome including a growing plant is capable of growing and

reproducing when planted out. A large number of bamboo species are propagated by Rhizome

planting. Some of them are Bambusa arundinacea, Bambusa vulgaris, Dedrocalamus strictus etc.

ii) Stem and Branch Cuttings

The cuttings can be of three types :

o Softwood,

o Semi-hardwood or

o Hardwood.

They are further divided into stem and branch cuttings. The softwood cuttings include

herbaceous cuttings i.e., a portion of soft succulent seed plants which do not typically develop

wood tissues, and green wood cuttings i.e., cuttings taken prior to lignification. The differences

between hardwood and greenwood cuttings are determined by the degree of lignification of stems.

The cuttings of 1-2 year old growth are taken out in dormant season when the tissues are fully

matured. The cuttings of size 20-25 cm long 1 to 2 cm diameter are prepared by a sharp

instrument. The lower cut is given in a slanting manner. The cuttings are taken out from the aerial

parts of the parent plant. The lower leaves are removed from the cuttings whereas upper leaves

are retained. The bases of the twigs are embedded in the well prepared nursery beds or polybags

containing moist rooting medium for rooting to occur. Softwood cuttings root faster and more easily

than hardwood cuttings. In conifers, cuttings collected from the healthy lower branches root better.

Sufficient moisture in the soil and humidity in the atmosphere is necessary. Fungus, bacteria and

nematode attack should be checked. While planting the cuttings are buried about two-third inside

the soil in a slanting position. The end of the cutting in the soil should not be loose to allow air to

come in otherwise rooting may not occur at all. The soil should be good sandy loam with good

fertility. To prevent evaporation of moisture, watering with fine rose is done till new leaves come

out. Watering should be sufficient. In nurseries, cuttings can be raised in beds, trays, polybags or

any other containers. For favourable root development soil temperature between 650F to 700F is

desirable. Some popular species preferred for cutting are : Poplars, Alnus, Willow, Mullberry,

Bougainvillea, Bamboos Grewia, Duranta, Bursera, Platanus, Lagerstroemia, Plumeria rubra,

Boswellia serrata, Tamarix aphylla and Ficus. Sometimes Bamboos like Bambusa vulgaris etc. are

raised by cuttings.

iii) Root section cuttings

The propagation by root cuttings is generally limited to plants, roots of which are capable of

producing shoots. Buds are either formed from the latent buds laid down during the initial period of


- 146 -

growth or from adventitious buds formed after roots are taken out. The length of root sections may

vary from 5 cm to 30 cm and diameter from 0.5 cm to 2 cm. Root sections are cut during dormant

season of plant growth. These are called “thongs” and put in the soil horizontally. Tree species like

Bombax ceiba, Artocarpus indica, Ailanthus excelsa, Robinia pseudacacia, Cinnamomum

camphora, Ougenia oojeinsis, Capparis aphylla, etc. can be raised by this method.

iv) Root and shoot or stump cuttings

For the species such as Tectona grandis, Bombax ceiba, Gmelina arborea or Dalbergia

sissoo, stumps are prepared from nearly one year old seedlings raised in the nursery beds. The

plants are taken out or uprooted with naked roots. The main axis of plant is cut to include a portion

of stem and taproot having nearly 30 cm length. The cut is given just 2 or 3 cm above the collar

with a sharp knife, axe or pruning scissor. The length of a normal stump for teak is nearly 8 to 10

inches. The taproot is cut at 15-25 cm from collar. The thickness may vary from 1 to 2 cm. For

Dalbergia sissoo the normal stump size can be about 6 inches. Planting by this method is

convenient and economical. In dry areas longer root-shoots are required. Undersized stumps can

be planted in polythene bags for beating up of causalities.

Layering

Layering is a common practice to form roots on branches when they are attached to the

tree. After rooting, stem is detached and planted. Layering can be of two types :

Air layering

Soil layering

Air Layering

The air layering is employed for plants that do not graft or do not root from cuttings. Air

layered branch is a part of parent tree even after layering and have in general better balanced root

system than cuttings. In this method a strip of bark or cambium is removed around the branch

before or during the summer and then this wound is covered with moss or other moisture holding

material and tightly fastened around with polythene piece so that moisture is retained. Root

inducing harmones can also be applied. It takes nearly 3 to 4 months in rooting. After rooting

branch is severed and can be used for planting in pot or whereas desired. Dalbergia sissoo, Morus

alba, and Ficus carica can be propagated by air layering.

Soil Layering

One end of the branch or shoot is bent and buried flat into the soil. When adventitious roots

are developed at the base these are severed or removed to form new plants. For some species a

ring of bark 1 cm wide is removed at a place where rooting is desired. Morus alba and Ficus can

be propagated by method.

Grafting

Grafting is the joining together of plant parts by means of tissue regeneration. The part that

provides the root is called the stock and the added piece is called the scion. The scion is detached

from the parent plant and the shoot of the other plant is severed to get a new plant. The success of


- 147 -

the graft depends on the matching of the cambia of scion and stock. The scion and stock can be

united in many ways and this decides the type of grafting. When the scion consists of a single bud

the process is called budding. In grafting the stock and scion is placed in intimate association so

that the resulting callus tissue forms a living continuous connection. Tape, rubber, etc. can be

used to achieve close contact. The grafting is successful when the stock and scion are of the

same species. Grafting is impossible or very hard to promote rooting in different species. Normally

dormant scion and actively growing stock are collected. The best period of grafting begins when

the buds of the stock plants start to swell and continues throughout late-spring. Soft-wood grafting

is done from late spring to early summer. Grafting in winter is not done as low temperature will not

allow the survival of grafts. If the scions are to be transported to long distance the cut ends are

dipped in melted wax to check drying. The various type of grafting are : cleft grafting, veneer

grafting, side grafting, whip and tongue grafting, splice grafting, bark grafting, etc. In cleft grafting

the shoot tip of stock plant is removed and a vertical cut is made through the centre of pith. The

scions 30 to 45 cm long are prepared by making tapering cuts in the form of wedge-shaped

segment. Now the scion is inserted into the split and the union is fastened by rubber or tape. The

stock is selected from 2 to 3 year old nursery plants having girth of 1 to 2 cm at 20 to 25 cm height

from the ground. April and May are the best period for cleft grafting. In veneer grafting the base of

the scion is cut diagonally and a wedge shaped patch of bark of almost same size is removed from

the side of stock. Now the scion and stock after matching are tied together. After the graft when

union gets healed the upper portion of the under stock is removed.

Budding

In budding, a bud with some portion of the bark of a genetically superior plant is grafted on

an inferior plant to produce shoot when the old shoot of the stock is cut off. The bud is grafted in

the form of a patch after removing the bark of the stock or by making a T-shaped incision in the

stock. The scion is tied on the stock but the uncovered. April and may are the best period for the

budding. The budding has been demonstrated for raising teak seed orchards. The teak seed

orchards raised through bud grafting can be used for getting quality seeds of teak.

Vegetative Propagating Structures

The various types of propagating structures are :

1. Shed-roof

2. Shade house

3. Propagating frames or misting units

4. Green house

5. Mist chamber

6. Growth area chamber or hardening chamber

All these structures aim to optimize following five environmental factors that are necessary

for growth and development of plants : (i) light (ii) water (iii) temperature (iv) gases and (v) mineral

nutrients.


- 148 -

Plant Tissue Culture or Micropropagation

In macropropagation such as through cutting, budding, grafting, air layering etc., large pieces of

tissues are involved, but in the plant tissue culture technique or micropropagation, very small plant parts,

tissues or cells are used. Plant has the potency to regenerate whole plant from single cell; therefore it

can be multiplied by tissue culture technique. For this any part of the plant like root, apical

shoot/meristem, axillary shoot, leaf, anther, microspore, ovary, ovule or embryo can be used explant from

the parent plant. Micropropagation produces many propagules from each original explant. Whereas

vegetative propagation methods do not produce significant results as compared to the tissue culture

technique. In this tissue culture technique small space is needed for rapid production of large amount of

material throughout the year without depending on season. Special laboratory having low temperature

(25 20c), light 2-4 K lux, and relative humidity, 60% is developed to prepare tissue culture plants. In vitro

cultures can be developed by adventitious means or directly from dormant buds of leaf axil, which may

be axillary or terminal. One shoot bud can yield 3 to 10 plantlets within 3 to 4 months depending upon

plant species and physiological status of the explant. The methods include induction of adventitious buds

on cultured explant like cotyledon and entire embryos, induction or stimulation of adventitious or axillary

buds on cultured shoot tips and regeneration of adventitious shoots and complete plants from

unorganised callus and cell cultures. Both macro and micro methods share similarity in respect of

physiological principles of auxins which induce root formation. The species that are easy to root through

cuttings etc. are also easy to multiply in culture.

Medium

The basal medium generally used for tissue culture is Murashige and Skoog (MS) medium

which consists of all the essential macro and micro-elements, vitamins, amino acids, carbohydrate

etc. for the plant growth and development. Agar-agar (0.6-1.0%), is used as gelling agent in the

medium. Basal medium is supplemented with auxins (IAA, IBA, NAA, 2, 4-D, 2, 4, 5-T) and

cytokinins (kinetin, BAP, 2-IP, Zeathin) either alone or in combination in different concentration &

depending upon the objectives. Generally high auxin (1.0-5.0 mg/l) and low cytokinin (0.1-0.5 mg/l)

are used for callus induction and reverse of it is used for shoot induction. Auxin alone (0.1-5.0

mg/l) with low salts medium (half or one fourth strength of MS) is preferred for root induction from

the micro-shoots in culture.

Medium used for Shoot Induction and multiplication

(a) Shoot induction and multiplication medium ; MS + IAA (0.1-

0.5 mg/l) + BAP/Kn (1 to 10 mg/l)

(b) Callus induction medium ; MS +

NAA/IAA/2, 4-D (1-5 mg/l) + Kn (0.1-1.0 mg/l)

(c) Callus differentiation medium ; MS +

IAA/NAA (0.1-0.5 mg/l) + kn/BAP (1.0-5.0 mg/l)

(d) Root induction medium ;

MS/2 + IAA/NAA/IBA (0.1-10.0 mg/l)

Kn-Kinetine; BAP- benzylaminopurine.

Cultures


- 149 -

The different types of cultures are :

(i) Embryo or Cotyledon Cultures

Embryonic or very young (less than 2-3 months old) seedling tissues can be used both for

hardwood as well as for conifer trees. The shoot buds are induced with one or more cytokinins.

The cytokines are removed then to elongate buds into shoots. Shoots are now treated with an

auxin to induce root initiation after which removal of auxin permits roots elongation.

(ii) Shoot Tip Culture

Shoot apex or shoot tip culture includes culture of the shoot apical meristem from terminal

or lateral buds which generally include many leaf primordia. The adventitious shoot buds or shoots

buds in the axils of branch are stimulated with cytokinins. These buds when elongated are

separated and rooted with auxins. The hardwood trees which are 100 years old have been

induced to micropropagation.

(iii) Callus and Cell Cultures

Callus tissues are formed when the plant is injured. Callus tissues grow in an unorganized

manner. These callus cells may be grown (a) on a solid nutrient medium or (b) as a cell culture i.e.

suspension medium of cells in liquid medium. The treatment with cytokinins induces callus cells to

elongate into a shoot which are then treated with an auxin to form roots. High frequency plant

regeneration can be obtained from the callus either by direct differentiation in shoots or through

somatic embryogenesis. The plantlets formation through tissue culture have been achieved in

Dalbergia sissoo, Santalum album, Eucalyptus hybrid, Tectona grandis, etc. but the transfer of in

vitro raised plants is hardly any successful. The trees plantlets are not easy to take to the field. For

the forest tree improvement and propagation, Indian Council of Forestry Research and Education

(ICFRE) institutes at Coimbatore, Jabalpur and Jodhpur are actively engaged on micropropagation

through tissue culture. They have taken up important species like Tecomella undulate, Anogeissu

pendula, Azadirachta indica and Dendrocalamus strictus to multiply through tissue culture.

Micropropagation technique has already been developed for the Anogeissus pendula and A.

sericea. In the recent years, pilot plants, have been established in Tata Energy Research Institute,

Delhi and National Chemical Laboratory, Puna, for the large scale micro-propagation of important

tree species.


- 150 -

Management of Seed Borne Bacterial Diseases in Seed Production Plots

Y. Singh

Department of Plant Pathology, G.B.P.U.A.&T., Pantnagar-263145 (Uttarakhand) Use of clean seed and clean transplants is recommended as the starting point for

managing plant diseases. Starting crop production wilt clean seed and or transplants seems

simple, logical and obvious, yet it is very difficult to achieve. Seed borne bacterial diseases

continue to be problematic and cause significant economic losses worldwide. Infested seeds are

responsible for the reemergence of the diseases of the past, movement of pathogens across

international borders, or the introduction of diseases into new areas. In today’s era of globalization

and free trade, seed accounts more than ever for the movement of plant pathogens across vast

distances, natural barriers, and political borders. Seed borne bacterial pathogens are of particular

concern, because, unlike seed born fungi, strategies for the management of bacterial diseases are

inadequate. Therefore, in this write up, attempt has been made to address various strategies for

the management of seed borne bacterial diseases.

(I) Quarantine: The first step in disease control is to prevent movement of the pathogenic

bacterium from infested to non infested areas by restricting the transfer of seeds, vegetative

propagules, plants and plant products etc. Both international and domestic transfer may be

potentially controlled by plant quarantine regulations. Many plant pathogens introduced from

abroad have caused serious epidemics in new areas where they were previously unknown. In

India 550 plant pathogens have been notified in the Plant Quarantine (Regulation of Import into

India) Order, 2003. Out of this, 65 are plant pathogenic bacteria. The hazardous means of

introduction of phytopathogenic bacteria are on the infested or infected seeds, and budwoods and

young plants. It is imperative to detect, isolate and identify these bacteria by following specific

detection techniques to avoid inadvertent introduction of the exotic quarantine bacteria.

(II). Disease management by cultural /farming practices

A. Production and use of pathogen free planting material

Many bacterial plant pathogens are transmitted by establishing themselves on or in the

seed or other vegetative propagating material or as contaminants . For successful disease control

this source of inoculums must be destroyed.

i. Seed production areas:- Seed should be produced in areas where the pathogens of major

concern are unable to establish or maintain themselves at critical level during periods of seed

development. Areas with low rainfall and low relative humidity are favourable for production of high

quality seeds e.g., bacterial blight of legumes. Certain guidelines have been suggested for

watermelon seed production free from bacterial fruit blotch of cucurbits (BFB) caused by

Acidovorax avenae sup sp. citrulli . These guidelines include producing seed in dry and cool


- 151 -

climate and in countries or areas of Countries, known to be free of the pathogen (Gitaitis and

walcott, 2007).

ii. Inspection of seed production plots:- Periodical inspection of crops raised for seed

production is an important procedure in the production of clean and healthy seeds. Destruction of

diseased plants/ organs at the time of inspection helps in reducing inoculum in the field and thus,

the percentage of healthy seeds in the produce is increased. If the disease incidence is very high,

the entire crop may be rejected for seed. However, Walcott et al., (2003) demonstrated that

symptomless watermelon fruits derived from symptomless plants could still harbour infested seed.

A. avenae sub sp. citrulli was detected in seed from 44% of the watermelon fruits that developed

from inoculated blossoms, despite the absence of fruit symptoms.

B. Eradication

Eradication methods are applied directly against the pathogen, to the host plants or

alternate hosts. Practical eradication procedures include fumigation of storage houses and

machinery, heat treatment, solarization , or flooding of soil, and burning or removal of plant

residues.

C. Field hygiene

Removal of diseased plant or plant parts from field is important to reduce the density of

inoculum. Defoliated leaves of pruned twigs of fruit trees and straw of cereals are preferably burnt.

Infected woody stems such as tomato, eggplant and tobacco should be ploughed into soil because

they may remain partly undecomposed in the soil. Disinfection of tools and equipment is important

to control the spread of bacterial pathogens through pruning or harvesting practices.

D. Control of weeds and insects

Another aspect of field sanitation is keeping the field free from weeds and insects. Weeds

reduce the amount of nutrients available for the plants and by lowering their vitality increase their

disease proneness’. Excess of weeds in the field also helps in increased humidity. In addition

many weeds harbour the pathogens which subsequently on release attack the crops in the field.

Bacterial leaf blight of rice Pathogen survives on weed (Leersia spp.) which grows along canals

and ditches. The bacterium is dispersed through irrigation water and infects rice seedlings in

lowland nurseries or those transplanted in paddy. Cruciferous weeds play role in disease

development of black rot of crucifers. Therefore, as sanitary precaution destruction of these weeds

is necessary. Diseases like black rot of crucifers are facilitated by injuries caused by insects such

as stripped cabbage flea beetle, cabbage worm and cabbage armyworm.

E. Disinfection of Seed and planting materials:-

In perennial crops such as fruit trees, new diseases are often introduced by infected

nursery stokes. Crown gall, citrus canker, and fire blight pathogens have been spread in this

manner. Because bacterial wilt of carnation is mostly spread by cuttings , hygienic treatment is

required throughout the entire process of propagation. In seed borne diseases, the frequency of

primary infection through infected seeds is generally low. However, pathogens can readily


- 152 -

disseminate from the primary infection centers by wind driven rain droplets, aerosols or farming

practices. The disinfection of infested or infected seeds by heating or chemicals is, therefore an

important and effective measure to eliminate the primary inoculum and to prevent disease

establishment in fields.

Hot water treatment of 450C for 20 minutes effectively eliminated Erwinia spp. on bulb of

garlic and increased the yield by 26.68 %. Application of Agreft 20WP (0.2%) applied as drenching

and spraying could suppress Erwinia spp. infection by 38% (Hanudin and Handayati, 1992). Hot

water and bactericide treatment of seeds has been found effective in reducing disease incidence

of watermelon fruit blotch (Nomura & Shirakawa, 2001). Hot water treatment of seeds at 500C for

15-20 minute has been found effective for the management of black rot of crucifers. Infection of

bacterial canker of tomato is also eradicated by treating with hot water at 550C for 25 minutes.

F Disease escape

Plants can escape from bacterial infection by a change in their cultivation period. Severe

damage of BLB in rice could be avoided by planting early maturing cultivars and setting the

cultivation period early enough to harvest before the typhoon season starts.

G Rotation

Because the same pathogen may survive in the field and cause infection in addition to

infection through infested and infected seed, disease development may be controlled by practicing

at least 3-4 years crop rotation. However, rotation may not be effective when the pathogen have

wide host ranges or are well adapted for long term survival in the field.

H. Irrigation

In potato common scab caused by Streptomyces scabies, irrigation for several weeks after

tuber initiation is effective in reducing scab. Practical control of the disease at the Rothamstad

Experiment station is accomplished by irrigation that maintains a soil moisture deficit of 0.6 for 3-4

weeks in the tuber initiation period.

I. Nutrition and Plant Density

Adequate plant density and fertilization are obviously important for growing healthy plants.

High nitrogen levels and dense spacing may increase disease susceptibility of host plants and

resident populations of the pathogen because proliferated dense foliage reduces air movement

and drying of leaf and stem surfaces.

J. Grafting

Muskmelon and watermelon are usually grafted on pumpkin root stocks to prevent infection

of Fusarium oxysporum f. sp. melonis and F. oxysporum f. sp. niveum. Severe infection due to P.

syringae pv. lachrymans and X. campestris pv. cucurbitae may occur on these plants through

pumpkin stocks that are raised from infected seeds. To control bacterial wilt, tomato and eggplant

may be grafted on root stocks of LS-89, Solanum torvum, S. intergrifolium or S. mammosum that

are highly resistant to R. solanacearum.


- 153 -

(III). Disease resistant varieties: - Use of disease resistant cultivars is economically and

technically the most practical method of disease control. A number of breeding programmes have

been highly successful, and commercially acceptable cultivars are available against many

bacterial diseases.

(IV). Biological control:- Biological control has attracted great interest is plant pathology

because the unnecessarily frequent use of pesticides is increasingly causing concern in terms of

human toxicity and hazardous effects on natural environment. A practical method of commercial

biological control is found in crown gall and has been developed in Australia with the strain K-84 of

A. radiobacter. This is undoubtedly one of the most innovative and important advances in

biological control of bacterial plant diseases. The effectiveness of the method has been confirmed

in many laboratories in the world with various host plants such as Prunus, Rubus, Salix, Vitis ,

Chrysanthemum, Rosa, Pyrus, etc. Because damage due to crown gall is particularly severe on

young trees, control with the strain K-84 is effective in preplanting dip of Seeds, cuttings, or grafted

nursery plants. Fungal biocontrol agent Trichoderma sp. (strain SKT-1) at 2 × 105-1× 106 conidia

/ml gave high control of bacterial seedling blight, bacterial grain rot and bacterial brown stripe of

rice (Kumakura et al., 2003) Biological seed treatment with antagonistic Pseudomonas fluorescens

has been shown to drastically reduce the bacterial wilt incidence in chilli caused by Burkholderia

solanacearum (Umesha et al., 2005)

(V). Chemical Control:- Chemical compounds used for controlling bacterial diseases include

streptomycin, kasugamycin, oxytetracycline, novobiocin copper compounds, polycarbamate,

tecloftalam and pyroquilon as foliar sprays, sodium hypochlorite and oxolinic acid as seed

disinfectants and metam- ammonium and thiram as soil disinfectants. Sodium hypochlorite is used

for sterilizing the surface of such fruits as oranges and apples. It is also widely used for disinfecting

seeds, tubers and agricultural equipments.

REFERENCES

1. Gitaitis, R and Walcott, R. 2007. The epidemiology and Management of Seed borne Bacterial Diseases. Annu. Rev. Pytopathol.45; 371-97.

2. Walcott, RR, Gitaitis, RD and Castro, AC. 2003. Role of blossom in watermelon seed infestation by Acidovorax avenae sub sp. citrulli Phytopathology 93: 548-34.

3. Nomura,T and Shirakawa, T. 2001.Efficacy of hot water and bactericide treatment of watermelon seeds infested by Acidovorax avenae sub sp. citrulli, Proc. Kansai Pl. Protec. Soc. 43:1-6.

4. Kamakura, K, watnabe, S., Makino, T, Iyozumi, H, Chikawa, T and Nagayama, K. 2003. Effect of Trichoderma sp. SKT-1 on suppression of six different seed borne diseases of rice. Japanese J. of Phytopathology.69 (4) : 393-402.

5. Umesha S, Kavitha , R and shetty, H.S. 2005. Transmission of seed borne infection of Chilli by Burkholderia solancearum and effect of biological seed treatment on disease incidence. Archives of Phytopathology and Plant Protection. 38 (4): 281-293.


- 154 -

Seed Borne Diseases of Rice and their Management

A.P. Sinha & Lalan Sharma Department of Plant Pathology, G.B.P.U.A.&T., Pantnagar-263145 (Uttarakhand)

Rice (Oryza sativa L) is the major staple food for nearly one half of the world’s population.

There is a pressing need to double or even treble our rice production to keep pace with the increasing population. In the quest for increasing rice production, man has resorted to intensive methods of rice cultivation involving high-yielding susceptible cultivars, higher plant population per unit area, high doses of nitrogenous fertilizers and staggered sowing and planting which intensified the severity of several diseases.

Rice suffers from a number of diseases caused by fungi, bacteria, viruses and nematodes. Many of these pathogens survive on and /or in the seeds from one season to other season in different forms and initiate primary infection on the next crop of rice. Rice diseases, many of them being highly destructive in nature causing often total loss of crop yield, pose serious obstacles off setting the efforts to increase production levels. Brown spot and bacterial leaf blight are probably worldwide in distribution. Other important rice diseases are blast, sheath blight, false smut, bacterial leaf streak, and grain discoloration. Higher incidence of rice diseases has been reported from those rice growing areas where heavy doses of nitrogenous fertilizers are applied to high yielding cultivars. Some of the rice diseases are known to cause severe yield losses, depending on the degree of severity of the disease, crop stage and environment conditions. In the present disease management strategies, an integrated approach based upon host tolerance, judicious use of fertilizers, adoption of appropriate cultural practices , judicious use of fungicides and use of biological antagonists is suggested to minimize losses caused by these diseases. In this article an attempt has been made to furnish relevant information on the important diseases of rice and their management.

The seed borne diseases of rice may be broadly classified into two groups

i. Pathogens invading both hulls and kernels, and

ii. Fungi invading only hulls and producing spore masses on infected spikelets and

reducing the quality of the seed.

In addition to these, kernel bunt caused by Tilletia barclayana, false smut caused by

Ustilaginoidea virens becomes important at places. The inoculum of these goes along with the

seed as contaminant. In the second group number of week parasites and saprophytes e.g.

Curvularia spp. Alternaria spp. Epicoccum spp., Bipolaris spp. Fusarium spp. etc. attack the

glumes and cause various types of glumes and kernel discoloration, thereby reduce the quality

and germination of the seeds.

1. Blast

It is caused by Magnaporthe grisea which infects the plant from seedling to grain formation

stage; but the most diagnostic symptoms are produced on leaves as water –soaked, bluish,

spindle shaped lesions which turn grey in the centre, and is surrounded by a dark- brown band.

The most destructive symptom appears at the flowering stage causing ‘neek rot’ in which the grain

filling is partially or completely checked depending on the stage of infection. The disease spreads

mainly through infected seeds and host debris. In temperate and subtropical regions, the pathogen

over-winters as mycelium and conidia on diseased straw and seeds. In plains, over wintering; of

the pathogen on seeds has been reported, but their role in the perpetuation of the pathogen is still

not certain. The seeds from diseased panicles show the pathogen in the lemma, palea, empty


- 155 -

glumes, hilum and placenta. It is also observed on pericarp and in the endosperm. At the time of

seed germination the fungus grows from hilum through pericarp to the extruded tip of the scutellum

or epiblast to the coleoptile and then to the first leaf.

Several epiphytotics of the disease have been recorded in different parts of the world,

resulting in serious losses in yield. In korea, it is the only rice disease that has ever caused a

serious problem. The loss in yield during 1953, an epidemic year, was estimated at about 800,000

tons in Japan. Yield losses were estimated at over 90% in Bicol during 1962 and at 50-60% in

Leyet during 1963, in the province of Philippines. In India, epiphytotics have been reported in the

Tanjore area of Madras state in 1919. In the hills blast may cause more than a 65% loss in yield.

Control

Treat the seed with Thiram + carbendazim (1:1) @ 3.0 g/ kg or Beam @ 4 g/ kg.

Early plantings have less disease than late plantings.

Seedlings raised in upland nurseries are more susceptible to blast even after transplanting.

Close spacing also often increase the severity of the disease. Controlled irrigation water

reduces damage from blast.

Foliar sprays with carbendazim or Hinosan @ 0.1% in nursery, at maximum tillering stage and

at 50% flowering stages to check neck blast. Single spray of Beam @ 600g/ha checks the

disease development at all stages of plant growth.

2. Brown spot

It is caused by Dreschslera oryzae. The fungus infects at all the growth stages of the crop.

On leaves oval, light to dark brown lesions are produced which join each other and kill the leaf

prematurely it causes discolouration of grain at flowering stage and shriveling of kernel. The

disease is mainly seed-borne and causes seedling blight in cooler region.

Symptoms appear as lesion (spots) on the coleoptile, leaf blade, leaf sheath, and glumes,

being most prominent on the leaf and glumes. The lesions are brown at first, and later become

typically ellipsoidal, oval to circular measuring about 0.5-22mm x 2-5mm. At maturity, they have a

light brown or grey center with a dark or reddish brown margin. Larger lesions are typical of more

susceptible cultivars. On the coleotile, the spots are brown and small, whereas on the glumes they

are dark brown to black in colour with olivaceous velvety growth. In severe infection, the whole

grain surface becomes blackened and the seeds are shriveled and discolored.

Seedlings are often heavily attacked with numerous lesions about 2.5 mm in diameter and

in such cases, leaves may dry out and ultimately die. Badly affected nurseries can often be

recognized from a distance by their brownish, scorched appearance, although seedlings are

usually not killed by the disease. Brown spot infection has been found to cause grain yield losses

up to 29 per cent and seed rot up to 37.3 per cent. The disease is primarily seed borne but

primary infection is likely to be severe only when the soil temperature at the sowing time is below

260C. Black spots appear on glumes. Poor germination of infected seeds has been reported. Due

to general weakening of plants, shriveled and poor settings of seeds are common. Disease


- 156 -

involves attack on grains themselves. Glumes are covered with dense black mass of spores.

Such grains are undesirable for use as seed and reduce market value of the produce. Fungus in

husked rice grain is viable for three years. However, in rice panicles viability of the fungus has

been reported up to 5 years. Survivability period of the fungus in the seed varies under different

conditions. Padmanabhan (1974) demonstrated that the pathogen was viable from one year to the

next growing season only on the seed. The diseased seeds need not always necessarily give rise

to infected seedlings. Sometimes the coleoptile and roots are affected but due to the rapid growth

of leaves, lesions may not be formed on the subsequent leaves. Leaf spots generally arise from

secondary infection by air borne conidia. The plants are most susceptible when they are in boot or

in flowering stages of growth.

Keeping in view the nature of brown spot disease, its frequent and widespread occurrence,

it is necessary to manage the disease with an integrated approach.

Control

Seed treatment with Thiram @ 2.5g/ kg. reduce seed borne inoculum, increase

germination, seedling vigour

Field sanitation, crop rotation, adjustment of planting dates, proper fertilization and good

water management should be followed.

Severity of disease increases in potash deficient soils. Therefore potassic fertilizers should

be added to correct potash deficiency in soil.

Spraying of mancozeb @ 0.25% at an interval of 10-12 days as the initial symptoms of

the disease appears.

3. Stack burn

The disease, caused by Trichoconis pawickii Ganguly, was first recorded in 1947. Although

considered a minor disease, it is very commonly detected in the seed indicating wide occurrence

of grain infection due to the disease. Maximum spore load in the air around rice fields was

obtained at heading stage of the crop when infection of glumes may take place.

The mycelium of the fungus was observed in embryos of infected seeds clearly showing

that the disease is internally seed-borne. A technique was also reported for the separation of the

whole embryo of rice grains for the detection of fungal mycelium. The pathogen may cause loss of

seedlings due to the production of toxin by the fungus. Prominent disease symptoms develop on

the coleoptile at 280C while least favorable temperatures are 220 C with no disease development at

150C. In a study seed infection increased proportionately as the doses of nitrogen application

increased from 0 to 200kg/ha.

Control:

Seed treatment with mancozeb (0.3%) or hot water treatment is known to control seed-

borne infection.

Foliar sprays with fungicides like Hinosan, Kitazin and Benlate gave better control of both

sheath and grain infections.


- 157 -

4. Sheath rot:

It is caused by Sarocladium oryzae. Sheath rot was observed during 1972 and 1973 in

several states and its first occurrence in India was reported independently from Karnataka, Andhra

Pradesh, West Bengal and Tamil Nadu. Since then it has been reported from several other states

from Kerla, Orissa, Uttar Pradesh, Bihar, Punjab and Rajasthan. The pathogens attack the upper

most leaf sheath enclosing the young panicles. It causes total sterility, chaffiness and non-

emergence of panicles resulting in loss in grain yield. On 0 to 9 scale, disease scores up to 3 did

not cause yield reduction but scores from 4 to 9 caused 3 to 80 % yield loss. Discoloration of rice

seeds due to sheath rot pathogen has been observed. Qualities of rice grains are also affected.

Seeds germination / protien content of grains are also reduced. (Vidyasekaran, 1989). The

pathogen survives for 4 months in seed and 10 months in leaf sheath in the field.

Control

Seed treatment with Benomyl or carbendazim reduce seedling mortality and improve seed

germination.

Foliar sprays with carbendazim or propiconazole @ 0.1% is the effective treatment against

sheath rot.

5. Bunt of Rice

The disease occurs in most of the rice growing areas of the world (Agarwal et al., 1989). It

has been reported in India from Andhra Pradesh, Andeman and Nicobar, Orissa, Punjab,

Rajasthan and Tamil Nadu. The disease has potential to cause extensive yield loss to the crop. It

caused about 15 million dollars loss in the Texas region in the USA (whitney and Fredrikesen,

1971) and up to 87% panicle infection has been reported from Pakistan (Hassan, 1971). In India,

10-15% infection has occurred in Assam, 0.75-18.5% in Tamil Nadu, up to 27% in Orissa, 0.1-

22.5% in Karnataka, 0.2-1.6% in Andaman and Nicobar islands and 30% in Rajasthan

(Chowdhary, 1951: Widespread occurrence and up to 80% incidence (infected panicles) of the

disease have been observed in 1997 in the Punjab State.

The disease is found in the field at the time of maturity of the rice crop. Only a few grains

in a panicle are infected. Normally only a part of the grain is affected but many a times the entire

grain may be replaced by black powdery mass of bunt spores. The infected seeds often show

greenish black discoloration, which can be detected during visual observation of the seed lot.

Minute black pustules or dots can be seen on the glumes. In severe infections rupturing glumes

show beak- like out growths. When the smut balls burst open, the black powdery mass of the bunt

spores scatter on to the other seeds or leaves. Some times, the infected grains may be detected

by their dull color before the glumes burst open. Most often, in the field, the infected grains exhibit

no external symptoms.

The seed-borne bunt inoculum poses a serious threat for widespread distribution of

disease in rice growing regions. The partially or completely infected grains may not be easily

detected visually in seed lots. This may escape the notice of workers. Association of bunted seeds


- 158 -

with healthy lost may aggravate the inoculums potential. Moreover, the spores which infest soil are

also potential source for initiating infection either in the same location where rice is grown in the

preceding season or even to newer areas with the soil movement through irrigation.

The central Seed Certification Board has prescribed a maximum of 0.1% and 0.5% per

cent infected seed in the foundation and certified seed lots, respectively.

Control

The losses and damage caused by Tilletia barclayana are not heavy in most parts of the

country and therefore detailed investigation on suitable control measures has not been conducted.

Keeping in view the nature and etiology of the disease, following preventive /eradicative methods

for its control have been recommended.

Sowing of only healthy and uncontaminated seeds.

Chemical seed treatment with systemic fungicide, namely, Vitavax.

Spraying of Tilt @ 1 ml/l to the crop at flowering stages to restrict seed infection.

Sanitary practices to avoid soil infestation with bunt spores

Testing of seed health in laboratory before a seed lot is recommended for sowing.

Clean storage of seed after harvest. Grains from infected panicles should not be used

as seed.

6. Sheath Blight

Sheath blight of rice caused by Rhizoctonia solani was known from the beginning of this

century in some eastern and south-eastern Asian countries. In India sheath blight was first

reported from Punjab in 1963 and is now prevalent in almost all the rice growing tracts causing

concern to the rice farmers. There are various estimates for yield losses from negligible to 50%

when infection reaches to the upper moist flag leaf. Yield losses from 10 to 36% depending on the

growth stage of the plants have been recorded in Assam. Although there are records about seed

borne infection, the reports about extent of damage are conflicting. Seeds may be infected if the

fungus could reach the rachis through external infection but not internally. The rice seeds may

carry sheath blight inoculum and produce 4-6.6% infection in India. It is likely that the seeds on the

lodged panicles catch inoculum from soil. But on transplanting the infected seedlings are unable to

develop disease earlier.

The symptoms of the disease appears on leaf and leaf sheath at or above water level as

greenish-grey lesions, 2-3 cm long turning to straw colour and surrounded by bluish –grey narrow

bands. Lesions on the upper portions of the plants extend rapidly coalescing with each other to

cover the entire tillers from the water line to flag leaf. Hemispherical or spherical grayish- black

sclerotia are formed on the lesions which fall in the field with slight jerk. In diseased ear grains

remain unfilled.

Control

Burn the infected crop debris after harvest. Keep the field weed free and cleaning of

bunds is necessary to control the disease.


- 159 -

The primary inoculum comes from soil. There fore, less prone crop should be grown in

the infected fields.

Drain the water after pudding.

Spraying of propaconazole @ 1litre/ ha or hexaconazole @ 2 litre /ha at an interval of 15

days as the initial symptoms of the disease appear in field.

7. Grain discoloration

In the second group number of week parasites and saprophytes attack the glumes and

cause various types of glumes and kernel discoloration, thereby reduce the quality and

germination of the seeds. Seed discoloration of rice considered to be a minor disease till recently

is now receiving move attention in tropical rice growing areas. In many regions of India the early

maturing rice varieties grown particularly in the wet season are generally exposed to highly humid

and warm environmental conditions during the flowering and post flowering stages. Such weather

parameters are ideal for tropical fungi to colonize and/ or infect the crop. Since last few years the

maturing panicles of a large number of rice varieties have exhibited seed discoloration in various

parts of India. Rice seeds may be infected by various organisms before or after harvest, causing

seed damage in the form of discoloration. These discolorations could be pathological, non-

pathological or both in nature and depend upon the environmental factors interacting with inherent

reactions of host variety and existing microflora. Different names viz; ‘glume discoloration’, ‘dirty

panicle’, ‘pecky rice’ or ‘glume spot’ have also been assigned by number of workers to such

abnormality. Seed discoloration in rice has been reported from all over the world wherever rice

crop is grown.

Seed discoloration has been shown to result in poor seed setting in panicles, reduction in

seed quality and seedling vigour. Discolored seeds are distorted and result in reduction in their

germination which is proportional to severity of discoloration. Discolored seeds are lighter in

weight and may be blown off during the cleaning operations. Weight loss is associated with seed

discoloration as weight losses up to 31.2 per cent and 50.2 per cent have been reported in seeds

having less than 50 per cent and more than 50 per cent area discolored, compared with seeds

classified as healthy and with no discoloration, respectively. Reduction in seed yield due to seed

discoloration has been reported in case of infection by Bipoaris oryzqe. Sarocladium oryzae and

Alternaria padwickii. The viability and germination are reduced as a result of seed discoloration.

Reduced viability and germination due to seed discoloration has been observed and also that

seeds having discoloration on both embryo and endosperm regions result in maximum loss in

seed viability and germination.

The seedling vigour of rice is adversely affected due to seed discoloration. Ou (1985)

mentioned that Curvularia spp. causing black discoloration result in reduction of seedling vigour in

rice. It has been found significant reduction in seedling height due to seed discolouration. The

discolouration in the embryonal region significantly reduces shoot and root length in discoloured

rice seeds. The quality of the harvested product is of considerable importance. The presences of


- 160 -

discoloured seeds in high proportion in a seed lot have been shown to adversely affect the

appearance. Seed discoloration poses a serious problem in seed certification. Discoloured seeds

which may otherwise be viable with recommended germinability as per certification standards,

many a time may not be acceptable as a seed because of poor physical look and high expected

incidence of seed borne fungi. It has been observed that discolored seeds had lower dry weights

for rough and brown rice than healthy seeds. Investigation on milling qualities of discolored seeds

of varieties IET 7191, IR 50 and IET 9381 revealed a decrease in moisture content and brown rice

content whereas an increase in whit husk content, bran content and broken rice as a result of

increase in seed discoloration for less than 1 per cent to more than 50 per cent observed that

healthy seeds expanded more than spotted seeds on cooking.

Discolouration of rice seeds due to infection of Nagrospora spp., Alternaria alternata,

Curvualria lunata, Sarocladium oryzae, Drechslera oryzae has been shown to reduce seed vigour.

Fungal infection associated with discoloured rice seeds may result in deterioration of nutritional

value of seeds due to physical, physiological and chemical changes in seeds. The infection of

seeds by Bipolaris oryzae has been shown to increase protein content of infected seeds and

reduction in soluble sugar and starch reported decreased total sugars, protein, nitrogen, starch

and amylase content whereas increased phenol reducing sugar and amino acid content in

discolored rice seeds. Some of the fungi associated with seed discoloration have been shown to

produce mycotoxins in rice seeds. There is a report indicating production of a mycotoxin in yellow

rice seeds due to infection of Penicillium spp. Mycotixin produced by Sarocladium oryzae in

discolored rice seeds also showed hazardous effects. Report are also on hand indicating that

concentration of aflatoxin B1 produced by Aspergillus flavus in rice seeds increased from 30 ppb to

60 after storage.

Symptoms

The symptoms of the seed discoloration have been described by different workers

depending on fungi involved, such as red, pink, blue, purple, yellow brown black discoloration. Red

discoloration, yellow discoloration, pale brown to white glumes, black point, light brown tinge,

chest nut brown to white spots, black flecks, black dots, brown and purple discolorations, black

and brown spots black gumes and pale brown spots on glumes are some major types of

discolorations reported with rice seeds. Besides above-mentioned categories of rice seed

discoloration, spotting on rice seeds have also been reported ash gray, eye shaped, light brown,

dark brown, light pink, dark purple, light to dark brown spots and black discolorations from rice

seeds. A number of fungi have been found associated with rice seeds. Some of these fungi under

favourable conditions in a susceptible host are reported to cause seed discoloration, while some

do not exhibit any type of discolorations. All the fungi recorded on rice which have or have not

been shown to result in seed discoloration are given in Table 1.

Table 1. Fungi associated with different types of discoloration of rice Seeds

Sl. No. Type of discoloration Fungi


- 161 -

1. Ash grey Alternaria alternate

2. Black or brown spots Bipolaris oryzae

3. Black dots on gulme Phyllosticta, waracola, Sporidesmium, oryzaecolus

4. Black glume discoloration A.padwickii,B. oryzae, Cuvularia clavata,C. affini, C.eragrostidis, C.fallax,C. geniculata, C.inequalis,C. intermedia, C.lunata,C. pallescens, Nigrospora oryzae

5. Black point B. oryzae

-6. Brown or black flecks Penicillium, citroviridae, P. citrinum, P. islandicum

7. Brown discoloration Fusarium roseum, B. oryzae, N. oryzae

8. Dark brown spots B. oryzae

9. Dark purple discoloration B. oryzae

10. Ebony black to chocolate brown stains

C.lunata

11. Eye shape spot C. geniculata, C. lunata, Pyricularia grisea

12. Fluffy black seeds B. oryzae

13. Light brown discoloration Sarocladium oryzae

14. Light brown tinge B. oryzae

15. Light to dark brown dot like spots B. oryzae

16. Pale brown to white glume discoloration

A. padwickii

17. Pink grain discoloration Epicoccum purpurascens

18. Red discoloration Monascus purpurascens

19. Yellow discoloration Wolkia decolorans

20. General seed discoloration and spotting

A. alternate, A. padwickii, Aspergillus niger, Cephalosporium gramineum, Cercospora oryzae, Chaetomium sp., Chaetomium globosum, Cladosporium sp. Cladosporium cladosporioides, Curvularia affinis, C. eragrostidis, C.geniculata, C. lunata, C. pallescens, C. verruculosa, Fusarium moniliforme, F. graminearum, F. pallidoroseum, Magnaporthe salvinii, Microdochim oryzae, Nigrospora oryzae, Penicillium sp. Pestalotia oryzae, Phaeotrichoconis crotalariae, Phoma sorghina, Phyllosticta glumarum, Sarocladium oryzae, Trichothecium roseum, Verticilllium sp.

Factors affecting Seed Infection

The incidence of seed discoloration of rice has been shown to be influenced by

environmental factors prevailing at crop maturity, field and crop management practices and the

morphological characteristics of flower, a positive correlation was found between rainfall, relative

humidity and seed discoloration (Ray and Gangopadhyay, 1990). High temperature and frequent

rain especially at the time of anthesis have been shown to favour seed discoloration (Narain, 1992).

Sundraraman 1922) observed that heavy rain at the time of ear formation followed by flooding and ill

drained conditions favour seed discoloration due to B. oryzae. High temperature and humidity have

been shown to favour infection of A. padwickii and C. lunata (Tisdale, 1922; Martin, 1939). High

moisture content in rice seeds result in a higher seed infection by Epicoccum purpurascens causing


- 162 -

pink discoloration (tanaka and Tsuchiya, 1987). Prevalence of low temperature has been shown to

favour infection by Phyllosticta glumarum, Epicoccum hyalopes and Magnaporthe grisea (Padwick,

1950; Suryanarayan, 1958). Ray (1993) suggested that maximum seed discoloration occurs during

wet season when rainfall and relative humidity are high. Dash and Narain (1988) reported high

incidence of glume discoloration by several fungi in wet as well as dry seasons at some places due

to low temperature, which predisposes the crop to fungi.

Seed discoloration also increases with the increasing levels of nitrogen and phosphatic

fertilizers (Misra an Dharam Vir, 1992). Ayotada and Salako (1980) reported that the rainfed

wetland conditions and unbalanced nitrogen, phosphorus and potassium application favours seed

discoloration. Application of silica increased total seed weight and effectively reduced seed

discoloration (Yamauchi and Winslow, 1987; Korndorfer et al., 1999). Yamauchi and winslow

(1989) reported that application of silica and magnesium protected rice plants against seed

discoloration and seed yield increased by an average of 34 per cent. A higher seed infection and

discoloration was rerecorded when older seedlings were transplanted as compared to young

seedlings and discoloration was more in transplanted crop as compared to direct sown crop (Misra

and Dharam Vir, 1992).

In West Africa, coarse upland soils and free draining soil water regimes increased seed

discoloration severity while lowland soils and water saturation minimized it (Dobson and Aluri,

1990). Late sowing, wider plant spacing (20x25cm), less nitrogen fertilization, application of

chemical fertilizers in combination with cattle manure decrease the seed infection as well as seed

discoloration (Muhammad Saifulla et al., 1995; Mathew, 1996).

Control

Rice varieties/germplasms such as Improved White Ponni, Mahsuri, Intan Gowri, Prakash,

ADT 39 (IR8xIR20), RAU 4045-2A (Fine Gora x IET 2832), Panikoili,, CTH 4, IET 11220, CTH 3,

IET 10131, IET 10626, CTH 1, IET 11221 and Mangala were found resistant against seed

discoloration (Prasad and Tomar, 1989; and Muhammad Saifulla, 1996).

Seed treatment with different fungicides has been tried to reduce seedborne inoculum.

Singh and Kang (1992) found that seed treatment with Thiram + carbendazim controlled seed rot

and improved germination. Seed treatment with tricyclazole (0.2 per cent), carbendazim (0.2 per

cent) and mancozeb (0.3 per cent) gave effective control of P. grisea and B. oryzae (Geetha and

Sivaprakasam, 1993). Hetty and Shetty (1987) reported that paddy seeds treated with aqueous

extracts of stem bark, leaf and seed of Strychnos nux-vomica effectively inhibited the development

of Dreshlera oryzae, Trichoconiela padwickii, Alternaria alternata Nigrospora oryzae penicillium

spp. Curvularia sp and improved the germinability of the seeds.

Fungicidal sprays of carbendazim, mancozeb at flowering stage and of Mancozeb and

propiconazole at boot leaf stage effectively controlled A.padwickii, C. lunata, C. oryzae, B. oryzae,

F. moniliforme, F. pallidoroseum, C. pallescens, C. geniculata, C. eragrostidis, Nigrospora oryzae

and Trichothecium roseum causing seed discoloration (Sisterna and Ronco, 1994; Deka et al.,


- 163 -

1996). Sharma et al., (1987) observed that seed treatment with Derosal, Emisan and Thiram were

effective in improving germination of discoloration seeds.

8. Bacterial Leaf Blight

Bacterial leaf blight caused by Xanthomonas oryzae pv. oryzae is said to have been first

seen by farmers in the Fukuoka area of Japan in 1884. The disease has been reported from

Philippines, Korea, USSR, China, Indonesia, Taiwan, Mexico, Thailand, Bangladesh, Nepal,

Pakistan, Latin American Countries, Niger and West Africa, and Ukraine. The disease was first

reported in India by Srinivasan et al. in 1959 from Maharashtra, where it was widespread and

destructive since 1951. The disease appeared in an epiphytotic form in Shahabad district of Bihar

in 1963 on variety BR-34 (Srivastava and Rao, 1963). After the introduction and cultivation over a

large acreage of new high yielding but susceptible rice cultivars, the disease has become one of

the most serious problems on rice in India (Ou, 1972).

Reductions of 20-30 percent have been observed in grain yields when infection

was moderate and over 30 per cent when it was severe. A loss of about 47-75 per cent in yield

has been reported in artificially inoculated crop. Bacterial leaf blight caused yield losses up to 50

per cent in paddy field. The loss in yield has been attributed due to increase in chaffiness,

decrease in grain weight and number of panicle. As a result of reduction in the number of filled

grains in diseased panicle, a loss in weight of 20.38 per cent was obtained In assessing the effect

of X. oryzae, 33.2 per cent more chaffy glumes and reduction in 1,000 grain weight were recorded

in infected tillers than in healthy tillers. At IRRI, Philippines, losses in yield were 74.89 and 46.88 per

cent in IR-1 and Taiwan-8, respectively.

It has been observed that the bacterium commonly present in the husk and endosperm of

the grains. Survival of Xoo in the seed varied depending on the environmental conditions under

which seeds were stored. Under low temperature and low humidity Xoo does survive for more then

6 months, where as under high humidity and temperature survival was found much shorter. Ability

of seeds to transmit the disease to new plants has been reported by several workers. In China,

seed transmission is the main source of inoculum in field. Srivastava et al (1967) observed that

seed was able to carry the Xoo when planted following year. Seed transmission was found

negative in India, Japan and Philippines, where high humidity and warm temperature do exist

seed transmission does not play important role in transmission to new field.

Symptoms appear as yellow or straw coloured wavy water soaked stripes beginning from one

or both margins covering the whole leaf blade which dry premature. Lesions may develop on any

portion of leaf blade or on the mid rib. Small orange coloured beads may be seen in early morning

during wet nights. These are the bacterial exudates which further spread the disease when mixed

with rain water. Kresek phase is characterized by drying or wilting of the whole plant and may be

observed during early growth stage of rice plants up to 4-6 weeks after transplanting. The

infection becomes systemic and spreads through out the plant. The leaves roll inward

longitudinally along the midrib with dull green water soaked lesions on them followed by drying of


- 164 -

entire leaf and sheath. Under severe conditions, the infected plants are killed completely and look

like plants damaged by the stem borers.

Control

Apply balanced fertilizers. Excessive nitrogenous fertilizers should be avoided and it should

be applied in split doses.

Drain the standing water from the field.

Spray Streptocycline 15g+ copper oxychloride 500g dissolved in 500 liters of water in one

hectare as the initial symptoms of the disease appear. Second spray should be given at an

interval of 10-12 days.

REFERENCES

1. Bhatt,J.C. and Singh, R.A. (1992). Blast of Rice. In Plant Diseases of International Importance. Prentice Hall Inc. USA, pp 80-113.

2. Dodan and Singh, R (1996) False smut of rice: Present Status. Agric. Rev. 17: 227-240.

3. Gangopadhyay, S. and Chakrabarti, N.K. (1982) Sheath blight of rice. Rev. Plant Path. 61: 451-460

4. Kaul M.H, Sharma KK. 1987. Bacterial blight in rice. A review. Biol. Zent.Bl. 106:141-67

5. Padmanabhan S.Y. (1973) Control of Rice diseases in India. Indian Phytopath. 27: 1-28.

6. Padmanabhan SY. (1983). Integrated control of bacterial blight of rice. Oryza 20:188-94

7. Premlata Dath (1990) Sheath blight disease of rice and its management. Associated Publishing Co., New Delhi, 129 pp

8. Shukla, S.N.,.Sunder, S., .Singh, R., Sharma, S.K. and Sinha, A.P., (2003) Ann. Rev.Plant Path. 2: 351-378.

9. Singh, R. and Dodan, D.S. (1995).Sheath rot of rice. Intl. Trop. Plant Diseases, 13: 139-152.

10. Srivastava D. N. 1972 Bacterial blight of rice. Indian Phytopath. 25: 1-13.

11. Ou SH. 1985 Rice Diseases. 2nd

Edition, common wealth mycological Institute. Kew. England.pp370.

12. Roy, A.K. (1993) Sheath blight of rice in India. Indian Phytopath. 46: 197- 205.

13. Chahel, S.S. (1998) Kernel smut of rice. Nat.Agril.Tech.Inf.Centre, Ludhina. pp 8.

14. Savitri, H, and M.A.Sattar (1996) Bunt of rice. National Seed Project, Seed Technology Research Unit (N.S.P.) A.P.A.U. Rajendra Nagar, Hyderabad. pp5.


- 165 -

Insect Pest Stored Seed and their Management

S.N. Tewari Department of Entomology, G.B.P.U.A.&T., Pantnagar-263145 (Uttarakhand)

During storage the seed is infested by several species of insects belonging to order

Coleoptera and Lepidoptera.

Stored-product Coleoptera

FAMILY ANOBIIDAE

Small oval or cylindrical beetles with head strongly deflexed below the thorax.

Lasioderma serricorne (Fabricius) - Cigarette Beetle

Adult stoutly oval, 2-2.5mm long, light brown in color. Elytra smooth, with very short hairs,

but without striae. Antennae about half as long as body, 11 segment, 4-10 segment serrate.

Larvae white and scarabaeiform.

Stegobium paniceum (Linnaeus) – Drug Store Beetle

Similar to Lasioderma serricorne but last three segments of antennae form a large loosely

segmented club. Elytra have longitudinal striae.

FAMILY BOSTRICHIDAE

Body cylindrical, head ventral to prothorax. Pronotum have rasp like teeth or hooks,

antennae straight and have a loose 3 or 4 segmented club. Apically elytra flattened and slope

ventrally more or less steeply (declivity). Tarsi 5 segmented.

Rhyzopertha dominica (Fabricius) – Lesser Grain Borer

Adult 2-3mm long typical Bostricid . Pronotum rounded at front with transverse rows of

teeth. Flattened tubercles centrally and posteriorly. Scutellum between Pronotum and elytra almost

square. Elytra have regular row of punctures and short setae that curve posteriorly. Apically elytra

gently convex. Antennae 10 segment with a loose 3 segment club.

Larvae white and parallel sided. Leg short, head capsule small.

Prostephanus truncatus (Horn) – Larger Grain Borer

Typical cylindrical bostrichid shape. Body 3-4.5mm long. Declivity flattened and steep,

many small tubercles over surface. The limit of declivity Apically and laterally marked by carina.

Antennae 10 segmented with a loose 3 segmented club. Stem of antennae slender and clothed

with long hairs and the apical club segment is as wide as, or wider than , preceding segments.

Larvae white and parallel sided. Leg short, head capsule small. Thoracic segments are

considerably larger than those of abdomen.

FAMILY BRUCHIDAE

Body clothed in short hairs, compact. The elytra covers all but last abdominal tergum

(pygidium), antennae relatively long.


- 166 -

Callosobruchus chinensis (Linnaeus) – Pulse Beetle

Adults have a pair of distinct ridges (inner and outer) on the ventral side of each hind

femur, and each ridge has a tooth near the apical end. The inner tooth is slender, rather parallel

sided, and equal to (or slightly longer than) the outer tooth. Antennae pectinate in male and serrate

in female. Elytra pale brown with small median dark marks and larger posterior patches which may

merge to make entire posterior part of elytra dark in color. The side margins of abdomen have

distinct patches of coarse white setae.

Callosobruchus maculatus (Fabricius) – Pulse Beetle

Adults have a pair of distinct ridges (inner and outer) on the ventral side of each hind

femur, and each ridge has a tooth near the apical end. The inner tooth is triangular, and equal to

(or slightly longer than) the outer tooth. The antennae of both sexes are slightly serrate. Female

often have strong markings at elytra consisting of two large lateral dark patches mid-way along the

elytra and smaller patches at anterior and posterior end , leaving a paler brown crossed shaped

area covering the rest. Males are much less distinctly marked.

Callosobruchus analis (Fabricius)

Antennae filiform. Coloration and patterning of both sexes is similar to that of an average

female C. maculatus, except that the pronotum of C. analis is uniformly red-brown (usually black

or dark brown in C. maculatus). In freshly emerged specimens, white setae at the center of

posterior half of each elytron are very conspicuous in C. analis but inconspicuous in C. maculatus.

As in all Callosobruchus species, each hind femur has a pair of ridges on the ventral edge; in C.

analis the outer ridge bears the usual noticeable blunt tooth, but the inner tooth is usually much

smaller or even absent.

FAMILY CURCULIONIDAE

All adults are characterized by a rostrum, which is forward snout-like extension of the head

and carries the mouth part. The antennae are elbowed in shape while at rest. The larvae are leg

less

Sitophilus oryzae (Linnaeus) - Rice Weevil

Sitophilus zeamais Motschulsky - Maize Weevil

Both the species are almost indistinguishable from each other externally. Both have

characteristic rostrum and elbowed antennae which have eight segments and often carried in an

extended position when the insect is walking. Both species usually have four pale reddish-brown

or orange brown oval marking on the elytra, but these are often indistinct.

Sitophilus granarius (Linnaeus) – Granary Weevil

Sitophilus granarius is similar in appearance to S. oryzae and S. zeamais, but can be

distinguished by the absence of metathoracic flight wings (only small vestigial wings are present)

and by the oval shape of punctures on the prothorax.


- 167 -

FAMILY DERMESTIDAE

Beetles generally ovoid but some times stoutly oval in shape and vary in length from 1.5 –

12 mm. Usually clothed in hairs or colored scales. Antennae relatively short with 10 or 11

segments. A fairly distinct three segmented antennal club is common. The larvae are

characteristically very hairy.

Trogoderma granarium Everts – Khapra Beetle

Adults are reddish-brown, with or without darker vague marking, but the thorax is

darker brown. They are oval in shape and vary in size from 2-3 mm, females being

somewhat larger than the males. The dorsal surface is moderately clothed in fine hairs. A

median ocellus present between compound eyes. The number of antennal segment is

usually 11 but some fusion of segments may take place so that there can be as few as 9.

The fairly distinct antennal club consists of 3-5 segments. In the male the apical segment of

the club is much elongated in comparison with that of female. The antennae fit into ventral

grooves in the prothorax. The larvae are typically very hairy. Spicisetae of various length are

arranged over the dorsal surface and a ‘brush’ of long spicisetae on the ninth abdominal

segments project posteriorly like a tail.

Dermestes maculatus Degeer

The body of adult is subparallel and 6-10mm long with a dark brown or black cuticle.

Dorsally the body is clothed in black and grayish hairs. Ventrally, the abdomen is thickly

covered in white hairs with the patches of black hairs laterally and apically. Antennae 11

segmented and have three-segmented club. First instar larvae measure about 1.5mm; the

mature larvae are about 15mm. They are very hairy and have dark brown tergites between

which lie cream coloured inter segmental membranes.

FAMILY SILVANIDAE

Beetles generally parallel sided and rather short (2-4mm). Most species have projections

on the prothorax which are in the form of teeth or swelling at the anterior angle or several teeth

along the lateral margin.

Oryzaephilus mercator (Fauvel) and O. surinamensis (Linnaeus)

Adults of both species are slender dark brown beetle, 2.5-3.5 mm long. The antennae are

relatively short and clubbed. The prothorax have six distinct tooth like projections along each side.

The length of the temple (the side of head behind eye) is much shorter in O. mercator than in O.

surinamensis. The larvae are white, elongate, somewhat flattened and about 4-5 mm long when

fully grown.


- 168 -

FAMILY TENEBRIONIDAE

The adults are 3-10 mm long and usually rather parallel-sided. Antennae 11 segmented,

are of moderate length, and are either simple in form or have a more or less distinct club. Tarsi of

hind legs have four segments while those of the front and middle legs have five.

The larvae have a characteristic shape and are generally well sclerotized, often having a

distinctly banded appearance and one or two pointed projections (urogomphi) at the end of body.

Tribolium castaneum (Herbst) – Rust-red Flour Beetle

Adults are typically tenebrionid in shape, 2.3-4.4 mm in length and red-brown in color. The

males possess a hairy puncture on the ventral surface of anterior femur; this puncture is absent in

female.

The larvae are typically tenebrionid and possess two upwardly curved urogomphi on the

ninth abdominal segment.

Stored-product Lepidoptera

FAMILY GELECHIIDAE

Sitotroga cerealella (Olivier) - Grain Moth

The fore-wings are pale ochreous brown and often have a small black spot in the distal

half; they have a span of 10-18 mm. The hind wing have a long fringe of hairs, longer than half the

width of the wing and are sharply pointed at the tip. The labial palps are long, slender and sharply

pointed. The larva possesses true legs but the prolegs are greatly reduced and have only two

crochets each.

FAMILY PYRALIDAE

Ephestia (Cadra) cautella (Walker) – Almond Moth

The fore-wings of adult are greyish-brown with an indistinct pattern. The wing span is 11-20

mm. And both fore- and hind-wings have broadly rounded tips and only short fringes of hairs. The

labial palps curve upward in the front of head and are rather blunt at the tip.

Plodia interpunctella (Hubner)

The fore-wing of adult is cream coloured in the basal two-fifth, while rest of the wing is

copper coloured (dark reddish brown) with some dark grey markings. The wing span is 14-18 mm.

And the labial palps point directly forwards.

Corcyra cephalonica (Stainton) – Rice Moth

In the adults the hind-wings are pale buff, and the fore-wings are mid-brown or greyish-

brown with thin vague lines of a darker brown along the wing veins. The fringes of hairs along the

wing margins are relatively short and wing span is usually 15-25 mm. The labial palps point

forward or downward; in the female they are long and pointed and in the male they are very short,

blunt and inconspicuous.


- 169 -

Management of Insect Pests of Stored Seed

Adopt following code of practices at different stage for management of insect pests of

stored seed:

A.Harvesting and threshing stage

Harvest fully mature crop

Use only properly cleaned and disinfested equipments for harvesting operations

Use moisture, insect and rodent free threshing yards located away from stores and

godowns

Disinfest the threshing yards with recommended pesticides

o Deltamethrin 2.5 WP 40g/litre

o Malathion 50 EC 10 ml/litre

o Pirimiphos methyl 50 EC 10 ml/litre


- 170 -

Spray solution

o Smooth surface 3-5 litre/100 m2 area

o Polythene surface 3-5 litre/100 m2 area

o Rough surface 6-8 litre/100 m2 area

o Jute Bag 8-10 litre/100 m2 area

For threshing operations choose the equipment giving minimum breakage

Keep the polythene / tarpaulin sheet ready for covering of harvested crop or grain after

threshing for protection from untimely rain.

B. Preparation of grain for storage

Clean the seed.

If some grains are brocken during threshing, screen them out from healthy ones.

Dry the seed properly under sun or in mechanical dryers to bring its moisture content at

safe level

Before filling the seed in the storage receptacles, cool it to room temperature and fill

immediately after it.

To protect the seed from insect infestation it may be treated with deltamethrin 2.5 WP at

the rate of 40mg/kg seed

If the seed is not treated with insecticides and any infestation is noticed, fumigate the seed

with aluminium phosphide just after filling the grain.

C. Selection and preparation of storage structure / premises

Never store the seed in bed room.

Select only moisture proof, rodent proof, insect proof scientific storage structures which

could be made reasonably airtight.

Maintain perfect store hygiene as it is a pre requisite for successful storage and

effectiveness of all ongoing measures.

Always ensure that there is no entry of water inside the structure.

Remove all domestic articles from storage structure / premises; plaster the cracks and

cravices if any.

If rat burrows are there, seal them with brocken glass pieces, stone , concrete and cement.

Fix the wire mesh on ventilators or windows to check entry of birds.

Clean the storage structure/premises thoroughly and white wash it.

Disinfest the storage structure/premises before keeping the seed by spraying

Deltamethrin 2.5 WP solution

In case of bag storage, always stack bags on wooden or LPDE poly pellets which are

atleast 10 cm high.

Arrange the bag in 3or 5 units with ears of bags pointing inwards.

The size of stack should not exceed 4 and 3 meter high in case of jute and plastic bag


- 171 -

respectively.

Leave a space of atleast 1 meter between stacks or stack and wall and 1.5 meter between

stack and roof.

D. Storage of grain

After filling the seed, never keep the structure open for longer period as it will facilitate

infestation and entry of moisture.

Inspect the seed from time to time and adopt counter measures as per requirements.

As the chances of insect infestation and deterioration due to moisture are very high during

rainy season, special attention is needed during this period.

If there is any infestation or entry of water and increase in moisture in seed it should be

checked immediately.

If any stored grain insect or any other sign of infestation is noticed during storage period,

fumigate the grain immediately.

In fumigation phosphin is used under airtight condition to kill the insects.

o Aluminium phosphide (ALP) can be used on all type of grain, but only under

technical supervision.

o It is recommended only when relative humidity is above 30 per cent and storage

structure is completely airtight.

o It should never be used in living room.

o ALP 56% 3g tablet 1-2 tablet per tonne or 150 g/100 m3 (Grain

fumigation)

o ALP 56% 3g tablet 150 g/1000 m3 (Empty godown and shed)

o ALP 15% 12g tablet 1 tablet per tone or 600 g / 100 m3 (Grain fumigation)

o ALP 56%(F)10g bag 1bag/5 qtl grain(Grain fumigation)

o ALP 56%(F)34g bag 1bag/15 qtl grain(Grain fumigation)

The minimum exposure time depends on the temperature, the relative humidity and the

formulation used, and on whether there is any resistance against phosphine.

Under normal condition exposure period of 5 days is sufficient.

With a relative humidity of below 60 % up to 6 days and more

In case of resistance: at least 3 days more in each case

Fumigation is ineffective if the relative humidity is below 30 %.

When mites are present, a minimum exposure period of 10 days is required.


- 172 -

Nanotechnology in Diagnosis of Plant Diseases

D.B. Parakh, V. Celia Chalam & R.K. Khetrapal Division of Plant Quarantine, NBPGR, New Delhi- 110 012

The word nanotechnology derives from namometer, which is one-thousandth of a

micrometer (micron) or approximately the size of a single molecule. Nanotechnology is the next

revolution in science and technology for betterment of mankind. It is the next stop in the

advancement of miniature technology that gave us micro-electronics, microchip and microcircuits.

As microprocessors and microcircuits shrink to nanoprocessors and nanocircuits, in times to come

silicon chips will be replaced by bichips and DNA-chips by the use of nanotechnology.

Nanotechnology is the study, manipulation and manufacture of ultra-small structures made of as

few as one molecule. Nanotechnology manipulates a single molecule and measures the electro-

magnetic forces between them. It joints breakthroughs to those in molecular biology and can

accomplish many goals that are difficult or impossible to achieve by other means.

1. Plant disease diagnosis

2. Rapid diagnosis of tens of thousands of samples using microarray technology

3. Integrating nanotechnology in plant pathogens

4. Understanding biology of plant pathogens

5. Basic study of understanding host-pathogen interactions and analysis of various defense

responses in crops at nano-scale

6. Identify disease resistance in plants germplasm

7. Establishment of nano database on diseases and pest of high economic significance.

Research and development activities in the area of nanotechnology and plant health will

boost Indian Agriculture and trade in long run and will make it more competitive in years to come in

nanotech revolution.

The database of US Government Nanotechnology Programme will establish investigator

collaboration on animal and plant diseases and pests of high economic impact that are currently

endemic in US. This database will be utilized for international trade in agriculture.

As Plant Quarantine Division of NBPGR is the only R&D facility for plant quarantine setup

in India, therefore, a collaborative project using this frontier nanotechnology for rapid diagnosis of

pathogens in imported germplasm, screening of germplasm for disease resistance, establishment

of nano database on endemic diseases of high economic significance for international trade and

HRD in nanotechnology is of utmost importance.

The Government of India has already set up and Indo-US Nano Cooperation Group in High

Technology Cooperation Area in Department of Science and Technology, New Delhi in January

2005.


- 173 -

Application of DNA Techniques in Seed Industry

S. Marla Department of MBGE, CBSH, G.B.P.U.A.&T., Pantnagar-263145 (Uttarakhand)

The valuable contribution of seed industry in bringing high quality seeds of elite varieties &

hybrids of various crops to the fields of Indian farmers and making green revolution successful and

sustainable is highly appreciative. However with changing times there is a necessity to adopt new

technologies to improve productivity in farmers fields. Emergence of DNA based techniques such

as Molecular biology, genomics, proteomics and Bioinformatics has contributed to better

understanding of basic mechanisms of crop growth and yield improvement and with potentially

direct applications in seed industry. Today several molecular biology based DNA techniques for

easy identification of crop varieties/hybrids, identification & isolation of genes responsible for

agronomically important traits such as high grain yields, nutritional quality, resistance to diseases

& pests, drought etc. transgenic Cotton and rice plants with introduced pet & disease resistance

are an example of the success story.

We shall limit in this article on How DNA techniques can potentially benefit seed industry.

One of the prime mandates of seed production is mainteneance of seed purity starting from

nuclear seed to foundation seed Produced. Identification different crop varieties and hybrids with

easy to use simple techniques is the need of the hour. It is not always possible to identify a true

type of seed using field, morphological or biochemical techniques as there are not many

phenotypic markers available. Where as the existing differences among genotypes at geen level

using DNA techniques can record variations (polymorphisms) fully with out loss and influence of

environment. The DNA based techniques are cheap, efficient and much faster without having to

wait for the data recorded from raised adult plants in the field. Several scorable molecular (gene)

markers are now available (some linked to phenotypic traits such as seed color and shape) that

are being employed for true type seed identification, detection of diseased seed lots or presence

or absence of gene of our interest in the examined seed sample. Plant breeders can employ

these techniques to monitor flow of desirable parental geens across the segregating populationas.

The seed industry has already started using some of these techniques to true hybridity

testing or identification of an original variety. With increased theft of elite seed by some of the

spurious industry competitors, the DNA techniques are increasingly being accepted by Police and

Judiciary in conflict resolution as a valid proof.

The polymorphism which exists in different DNA sequences of crop varieties can be

studied by following either PCR based approaches or non PCR based approaches.

What is PCr (Polymerase Chain reaction) of DNA:

.The existing polymorphism among analysed varieties can be recorded at the level of DNA

employing molecular biology techniques- Polymerase Chain reaction (PCR) and Electrophoresis.

The variations (polymorphism) in DNA can be separated based on their nucleotide sizes and


- 174 -

viewed on a sheet attached to electrical current in the form of bands (tiny spots, Fig. 1 & 2).

However the quantity of DNA extracted from seed or leaf or root tissue is too small and it is

difficult to view such tiny spots. Hence the tissue extracted DNA needs to be amplified many

times to obtain required quantity using PCR. Thermal cycler is used for running the PCR reaction

and amplifieng DNA in sufficient quantities (Fig.3). To run a PCR the essential ingredients are-

High quality plant tissue extracted DNA, Primers( starter DNA for initiating amplification),

enzymes and chemical budffers to amplify DNA. DNA will only duplicate itself, if there is a primer

or “starter DNA” in the mix, which is compatible with the DNA. The primer sets (for duplicating

both forward and reverse DNA strands) specific to our Gene of interest can be designed insillico

using Bioinformatics tools such as PRIMER3 and DNASTAR.

Fig. 2. Thermal Cycler Fig.3. Gel Electrophoresis apparatus for

for DNA amplification. viewing DNA polymorphisms.

Two important commonly used techniques viz. RFLP and RAPD will be discussed in detail

below in order to explain their importance in discrimination of the crop varieties:

Various PCR or non PCR based molecular markers which are used for varietal

identification of crop plants are also used for determination of hybridity of crop plants. The use of

RFLP and RAPD in determination of hybridity is discussed below :

RFLP: RFLP markers behave as codominant markers. RFLP’s can successfully be employed to

determine genetic contribution of each parents and can be used to determine the extent of

heterozygosity. Two selected varieties ( say A and B) are crossed to produce F1 and F2/backcross

generations. DNA is isolated from the parental varieties, the F1 and F2 generation and used to

determine RFLP’s with various probes for which they show polymorphism. For example, probe 1

detects a relatively slower moving band in variety A and a faster moving band in variety B. These

bands may be regarded as two different alleles of a single gene, say allele A for slow moving band

and allele a for fast moving band. Similarly, probe 2 detects a fast moving band in strain A ( this

we may denote as allele b) and a slow moving one in strain B ( designated as allele B). The F1

hybrid between varieties A and B will show both slow and fast moving bands for each of the two

probes.


- 175 -

RAPD:

RAPD’s are generated by using random sequence, ordinarily, 10 base long oligonucleotides as

primers for PCR amplification of genomic DNA extracted from different varieties. Polymorphism is

produced due to complementary sequence for the primer used being used in one strain (variety A)

but not in the other ( variety B). As aresult an amplification product will be detectable as a band in

strain A while strain B will not show the product. The F1 hybrid will two strains will show the band

while in F2 a 3:1 ratio will be obtained. Thus RAPD’s behave as dominant markers. Further the

presence of amplification product can be regarded as dominant allele and it’s absence as

recessive allele.RAPds have similar applications to those of RFLP. However they are faster and

more convenient to perform than RFLP.

Biotechnological tool for maintenance of hybridity

Barnase-barstar system : Gene barnase encodes an RNAse which kills the cells in which it is

expressed by degrading RNA. The expression of barnase was confined to tapetal cells by fusing it

with the promoter of tobacco tapetum specific gene TA29 ( gene construct : pTA29- barnase; p

promoter ). When the chimaeric gene construct was transferred and expressed in tobacco and

oilseed rape, the tapetal cells of anthers were destroyed and there was no pollen development.

However there was no effect on female fertility. Since the male sterility due to barnase is

dominant, the male sterile lines are always heterozygous (barnase/- ; the – sign indicates absence

of barnase gene in homologous chromosome) and they have to be maintained by crossing to any

normal, non transformed male fertile line (-/-; barnase gene absent). Thus male sterile lines (

barnase/-) will have to be crossed to be normal fertile lines (-/-), and only 50% of the progeny from

such crosses will be male sterile while rest 50% will be male fertile (-/-). In a hybrid seed

production programme the male fertile plants present in male sterile line must be identified

andeasily eliminated. This has been done by linking the barnase gene with the bar gene from

Streptomyces: bar gene confers resistance to herbicide phosphinothricin.When such male sterile

(barnase-bar/-) plants are maintained by crossing with normal male fertile (-/-), all the male sterile

progeny ( barnase-bar/- ) are resistant to the herbicide, while all the male fertile plants (-/-) are

herbicide susceptible. The male fertile plants are therefore eliminated by a herbicide spray at an

early stage of plant growth.

The male fertility of barnase male steriles is restored by another gene, barstar, of the

bacterium B.amyloliquefaciens. The gene barstar encodes a specific inhibitor of barnase encoded

RNase. The barstar product forms a higly stable 1:1 noncovalently bound complex with the

barnase RNase; this reaction provides protection to the bacterial cells from their own RNase

product. Transgenic plants expressing barstar are male fertile without any phenotypic effect, and

are easily maintained in the homozygous state. When a homozygous barstar male fertile line is

crossed with a barnase male sterile all the progeny plants are male fertile since barstar gene

product effectively inhibits the barnase RNAse in barnase-bar/barstar plants. This male


- 176 -

sterility/fertility system has shown commercial promise in maize and oilseed rape and can be

easily extended to other crop species. The much popular Terminator technology is another

application of DNA technology with potential negative affects in favor of commercial seed firms

allegdly taking away farmers rights to recycle their own seed for future sowings.on farmers

rights.

Fig.1. Identification of True Hybrids

Finger Printing Verities & Hybrids

A DNA fingerprint can be called a genetic photograph of an individual, whether that

individual is a plant, animal or person. The technique of DNA fingerprinting has been developed

using the science of genetics. Genetics is the study of genes, tiny units of deoxryribonucleic acid,

or DNA. This chemical is located in the nucleus of every cell. An organism's DNA contains the

blueprint of its characteristics --in the case of plants, that would include features like yield, drought

resistance and starch content. Making a DNA fingerprint involves several steps as follows:

1. To obtain the DNA necessary for the test, a small sample of the plant cells is required.

2. The sample is treated with chemicals to extract DNA from the cells.

3. Enzymes (proteins which promote chemical reactions) are added to the DNA. The enzymes

act like scissors. They are used to cut the DNA into fragments of various lengths.

4. The fragments are placed on a bed of gel. Next, an electrical current is applied. The current

sorts the fragments by length and organizes them into a pattern. This process is similar to

placing sand in a series of sieves to sort the particles by size.

5. The DNA pattern is transferred to a nylon sheet by placing the gel and the nylon next to

each other.

6. A probe of radioactive DNA is introduced to the pattern on the nylon sheet. The probe,

which is a short strand of DNA treated to make it radioactive, is designed to bind to specify

DNA fragments.


- 177 -

7. Finally, X-ray film is exposed to the nylon sheet containing the radioactive probes. Dark

bands, which resemble consumer product bar codes, develop at the probe sites in a pattern

unique to the organism. The bands indicate the site where a probe has bound to the DNA

fragments. The DNA of each individual is unique, producing a unique set of fragments. This

makes each pattern of probe-binding unique.

Simplifying the Search

DNA fingerprinting can be of use to plant breeders to simplify their work and reduce the

amount of time it takes to produce crops with desirable new traits. For example, once a scientist

isolates a specific gene that expresses a certain crop trait, a batch of seed is then produced which

the scientist hopes carries the trait. At one time, the researcher would have to grow the crop to see

if the trait is present. But now, the DNA of the seed batch can be tested to determine if the seeds

contain the sought-after gene. The DNA test can also be used to identify and keep track of genes

as they are isolated and transferred into crops. As well, it can become a tool to simplify the more

traditional methods of selective breeding, by identifying what are known as "markers." Since DNA

fingerprints are taken from the same DNA that carries the entire genetic blueprint for the plant,

pieces of DNA that are close together tend to be passed on together from one generation to the

next. If one particular band of a DNA fingerprint is found to be inherited along with a useful trait,

that band serves as a marker for that trait. This marker shows which offspring may carry the trait,

without having to search for the specific genetic material.

Guaranteeing Crops

Protecting plant breeders's rights (the breeders' patents on specific types of seed), is

another use for the DNA test. Disputes over the true identify of seed varieties can be easily

resolved, since the test will be able to isolate the specific traits that distinguish one seed variety

from another. The ability to identify seed varieties will make the test important to guaranteeing the

authenticity of a crop being purchased. Often it is very important to the buyer that the crop being

purchased is of a particular type. For example, millers want wheat which produces a high quality

milling flour that can be made into bread. Pasta producers are looking for wheat which produces a

soft, doughy flour the kind that makes a good noodle. As well, new international rules are requiring

crops which are genetically altered to be separated from ordinary crops. Crops may have specific

genes inserted which, for example, make the plants resistant to a certain type of herbicide. This

herbicides resistance reduces farmers' input costs by reducing the amount of chemical they use to

control weeds.

Until recently, a commodity buyer had to rely on the seller for assurance that the crop was

exactly what the buyer wanted. With DNA fingerprinting, a buyer no longer has to simply accept

the sellers' word. Another way that DNA fingerprints can be used is if a farmer grows a crop and its

performance does not match the claims made for it. A fingerprint could be taken to show whether


- 178 -

the seed which the farmer planted was in fact the variety that was chosen. DNA fingerprinting may

also be used in the future to identify disease infection in crops. Each disease-causing agent, such

as a fungus, bacteria or virus, has a unique DNA fingerprint. If a DNA test indicated the presence

of a disease organism, infection might be detected at an early stage, and a farmer could take

appropriate preventive steps.

Building a Library of Varietal Finger Prints:

In order for the seed industry or others to effectively use DNA tests, both private and

government labs are working on building a library of crop DNA profiles. As new samples are

analyzed, a computer scan can produce matches between the samples and DNA profiles already

recorded. These labs plan to offer the testing service at a reasonable cost. That means DNA

testing will likely becomes as commonplace as other agricultural testing services, like soil sampling

and seed germination testing.


- 179 -

Role of Biotechnology in Improving Seed Health Management

Anil Kumar and Pushpa Lohni Department of MBGE, CBSH, G.B.P.U.A.&T., Pantnagar-263145 (Uttarakhand)

During the past two decades, the technology of producing seeds and seedlings has

developed rapidly. However, all this innovation means that the people involved in seed production

have a continuous need to update their expertise. With the increase in seed production, seed

health need to be insured. Seed health testing is essential for the control of seedborne and seed-

transmitted pathogens and continues to be an important activity for their regulation and control

through phyto-sanitary certification and quarantine programs in domestic and international seed

trade. Seed health testing is also critical for insuring the health of basic seed stocks used for seed

production and for plant germplasm utilized in research and product development. As a

consequence of increased product liability as well as competitive pressures within the seed

industry, seed health has also become an increasingly important quality trait in the marketplace,

particularly in vegetable crops. Seed health testing methods include examination of dry seeds,

seed soak and washing test, culture tests, infectivity test, seedling symptom test, histo-pathology

and molecular techniques such as immunoassays and nucleic acid based techniques.

Biotechnology has a great role to play not only in the production of healthy seeds and

planting material but also in detection of pathogens associated with seeds. Pathogens which can

induce systemic infection in their host plants include viruses, viroids, phytoplasmas and some

bacteria. As mentioned above, these pathogens can be transmitted from infected mother plants to

seedlings, or to planting materials such as scions, cuttings, bulbs, and tubers through vegetative

propagation. In fact, vegetative propagation by tissue culture, which has become the dominant

method of propagating numerous plant species, is considered to be the most efficient way of

multiplying and disseminating planting materials infected with systemic pathogens.

Disease surveillance programme

From seedling to harvest, constant vigilance against diseases is required in order to grow

healthy crops to its potential yield and quality. Diseases can reduce profits, and if detected late,

may cause total crop loss. An effective disease surveillance programme is thus mandatory to

combat major outbreaks of the disease. These measures can be put in place well before there are

any symptoms are seen in the fields by detection of the main disease entities of the causative

pathogens. An integrated package incorporating the use of fungicides against seed and air borne

inoculum, adoption of appropriate cultural practices and bio-suppression techniques against the

soil borne inoculum and use of host resistance is the key approach. However, seed health testing

and seed certification using modern diagnostic tools is highly advocated as an integral component

of this package. Therefore, efforts are needed to focus the attention of academia, the seed

industry and government on the following needs.


- 180 -

1. Determination of true incidence, causes and financial/ personal impact of seed borne

diseases.

2. Development of more effective methods of salvation and for the testing of seeds (routine

monitoring/epidemiological tools)

3. Divestment of better methods for controlling the risks associated with seeds.

4. Development of better means of risk assessment including pathogen load and

pathogenicity/ toxicity for crops and differential risks among other crops.

In order to limit the transmission of the pathogen in to disease free areas, transportation of

infected/ infested seed from the disease prone areas has been restricted. To meet the

requirement, the central seed certification board has formulated strict seed certification standards.

To limit the dispersal and build up of Karnal bunt infection, tolerance limits (certification standards),

based on visual inspection, are applied to foundation and certified seeds i.e., maximum of 0.05 for

foundation seeds and 0.25 percent for certified seeds. A seed-washing test to quantify the seed

borne teliospores for the purpose of seed certification has also been suggested. However, the

seed certification standards can be improved by taking account of the total pathogen load on seed

lot rather than per cent-wise infection which does not take of a grade of infection. If the teliospore

contamination is beyond 25 spores per grain, the seed lot is rated as contaminated.

The seed scientists have developed techniques for analyzing large numbers of samples for

seed certification and plant quarantine. The International Seed Testing Association (ISTA) has

important roles in defining and promoting standard procedures, and establishing tolerances for

seed tests. The advent of newer molecular diagnostics based on nucleic acid and immunological

reaction permit the sensitive detection of KB. The Pantnagar University took an initiative in 1997 to

combine the know-how so as to formulate standard detection and seed certification methods. The

immunological formats developed in our laboratory are quite promising not only for the detection of

Karnal bunt infection in seeds but also for use in detection of infestation of KB teliospores. The

significance of seed health testing is to ensure the safe movement of germplasms, for the purpose

of research and trade. It is also a means of quality control of seedling stocks for crop production.

Essential requirements of seed health diagnostics

In a regulatory climate in which the presence of a single pathogen could lead to regulatory

action, the need for a reliable method for detecting and identifying the disease entities in grains

can not be overstated. Such a method must meet three requirements: (a) a detection sensitivity

approaching few causative agents; (b) an extraction method that is quick and cost effective in the

evaluation of a large number of samples; and (c) compatibility with available biochemical,

immunological and molecular methods for identification of pathogenic entities.

Molecular diagnostics for diseases

Disease diagnostics and pathogen detection, a primary component of any crop

management programme, is also helpful in monitoring sanitary and phyto-sanitary measures to


- 181 -

seed quality. Molecular diagnostics based on immunological and DNA techniques can provide an

easy-art-technology for disease surveillance and disease forecasting. Testing for and monitoring of

pathogens is a component of seed quality control. For current seed health testing, seed-borne

pathogens are usually recovered by conventional agar plating, blotter tests or by serological

techniques. These traditional methods of detection and identification are often time consuming and

labor intensive. Over the past decade, considerable advancement has taken place in the

development of molecular diagnostics for detection of pathogens in seeds. Potential benefits

(rapid, same-day analysis specific and sensitive tests) this new technology offers make it

extremely attractive. The recent and rapid pace of developments in molecular biology has provided

new opportunities in diagnostic areas.

Modern diagnostic methods are based on high affinity biomolecular interaction between

ligand and binder. These include the nucleic acid hybridization (DNA based) and antibody based

techniques involving complementary interaction of DNA-DNA, DNA-RNA, RNA-RNA and antigen–

antibody (Ag–Ab) interactions that have been applied to KB diagnostics and pathogen detection at

the field level.

Sample preparation in diagnostics

The foremost element to be taken into account in the development and application of

analytical methods in plant diagnostics is the sample preparation. Discussion of some of these

methods is relevant at this stage because many of them are distinguished by the relative lack of

sample preparation required before the analysis can be performed. However, some methods do

require the sample preparation for biological amplification. The biological amplification consists of

extraction stage and culture of pathogen on an enriched medium. Table 1 summarizes attributes to

be considered in the primary selection of diagnostic methods for seed borne plant pathogens.

Extraction of seed-borne pathogens

Several methods of seed-borne pathogens isolation are a modification of general seed

wash assays and being currently used by most international seed health laboratories, that have

been improved by the incorporation of suitable detergents commonly used for extracting fungi from

soil.

Detection techniques based on cellular and molecular differences

For differentiating one from other pathogens many techniques can be employed. The

present methods for testing grain for the presence of seed borne pathogens include microscopic

analysis, pathogenicity tests; isozyme analysis that identifies disease causing entities. However,

the procedures have many drawbacks as they rely on individual examiners and are highly

subjective in their nature. The techniques include conventional techniques, biophysical, isozyme

and DNA based marker and immunological techniques.


- 182 -

Conventional techniques: Conventional techniques include light microscopy based detection and

morphological studies. The pathogen can also be distinguished by fluorescence microscopy

(epifluorescent microscopy).

Isozyme based techniques: Isozymes are enzymes which have the same substrate specificity

but different enzyme kinetics and molecular weights. Isozyme analysis is carried out to study the

genetic variation for taxonomy. However, use of such analysis is very tedious, cumbersome and

needs expertise.

DNA based techniques: Seed borne pathogens are often present in very low numbers in

contaminated seeds. DNA based techniques have been developed, which are highly sensitive for

the detection of pathogens. DNA based techniques can detect 2-3 cells per ml of original seed

washing. These techniques are 100 times more sensitive than other techniques. The polymerase

chain reaction (PCR) in conjunction with six short arbitrary primers of random sequences can be

used to perform RAPD profiling of seed borne pathogens and exhibit distinct polymorphic DNA.

Efforts are going on to develop an accurate molecular based method to identify teliospores of T.

indica using BIO-PCR. As few as 5 teliospores could be detected per 50 g of wheat seed. PCR

based technique is important in this case because KB teliospores are morphologically similar to T.

barclayana. At the FDWSRU, at Ft. Detrick, several real time PCR assays have been developed

using TaqMan probe. Initially developed using the AVI77100 sequence detection system, these

assays have been adapted for use with both the smart cyclers and the RAPID for rapid

identification at remote locations or at field sites.

PCR testing is very accurate, but it is also rather expensive and technically difficult. The D-

Genos firm from Angers (France) has developed assays based upon PCR (Polymerase Chain

Reaction) for the specific detection of pathogenic bacteria in seed soakings. Although DNA-based

techniques are generally accepted as being more sensitive and specific for pathogen detection

than the serological ones, they have some defects. These include the higher cost, the difficulty of

reproducing results, and the possibility of false positives and cross-contamination between

samples. These problems need to be solved before DNA-based techniques can be used as the

routine basis of diagnosis.

Immunological techniques: Immunological techniques are the most efficient for the detection

and differential diagnosis of the diseases. Various immunological techniques have been employed

successfully for the detection of various pathogens.

Immunoassay techniques to detect plant pathogens have been largely adapted from

methods widely used in medical diagnosis. They are now routinely utilized for disease indexing

plant material. Immunoassays have been revolutionized by the introduction of highly specific

monoclonal antibodies and enzyme linked immunosorbent assays (ELISAs) as routine methods to

detect only the molecules (antigens) or antibody binding sites (epitopes) that are unique to the


- 183 -

infecting organism, or its metabolite. These diagnostic assays are rapid and can be completed in

several hours instead of days or even weeks.

ELISA is an efficient and low-cost way to detect plant virus diseases. ELISA is based on

antibodies produced by animals (usually rats or rabbits). Provided suitable antibodies are

available, ELISA testing is usually the method of choice. It is sensitive, easy to use, and needs

minimal equipment. Enzyme-Linked Immuno Sorbent Assay (ELISA) has been modified into a

semi-automated system that can process thousands of samples in one day. When suitable

antibodies are available, the most sensitive and efficient test for plant virus is ELISA. ELISA is

widely used, since it is easy to apply and does not need any expensive equipment.

Immuno-detection strategies for disease surveillance

Several assay formats exist but the most common are the enzyme immunoassay based

systems. These formats have many advantages as they are highly sensitive, easily replicated,

automated and quantified. The only disadvantage is that they require lab facilities. A number of

'user friendly', membrane bound, dot blot and dipstick assays, which do not require laboratory

facilities have been developed and are being used increasingly as 'on site' screening tests. Some

immunofluorescence assays, which were developed for the immunodetection, have not been

adopted widely due to involvement of microscopy and a UV light source. In our lab we have

developed antibody and DNA-based as well as biophysical methods for KB diagnostics (Table 2).

Among the serological methods are micro-titre ELISA, Immunofluorescence staining test (IFST),

Seed immunoblot binding assay (SIBA), and Dyed latex bead agglutination test and immunodipstik

assay. These immunoassay systems could be allowed for reliable quantitative assessments in a

high throughput manner in regulatory laboratory facilities if developed in an appropriate format

such as easy- art technologies in the form of kits. They would be well suited for detecting KB

infestations in the field. The immunodiagnostic assays for field use are inexpensive, rapid and do

not require highly trained personnel.

Seed health testing: An integral component of disease management

The Seed Health Testing Laboratory tests for over 200 viral, bacterial, and fungal

pathogens on most crops, including corn, soybeans, vegetables, and flowers using a variety of

methods. Tests are available to address nearly all phytosanitary and quality assurance concerns.

All phytosanitary certification is performed in accordance with National Seed Health System

(NSHS) standards. The Seed Heatlth Testing Lab is NSHS accredited, in accordance with USDA-

APHIS regulations.

Customers typically inquire in regards to particular seed health testing as quality

challenges arise in field or storage. Below is examples of the test available, but many other

pathogens are available.

Techniques


- 184 -

Examination of dry seeds: i. Visual observation of seeds. ii. Observations using a bright field

microscope. iii. Observation under near-ultraviolet/UV light. iv. Use of adhesive tape.

Seed soak and washing test: i. Seed soak test. ii. Washing test. iii. Spore identification.

Culture methods: i. Incubation methods. ii. Dilution plate method. iii. Fluorescence method. iv.

Tissue culture. v. Conductimetric assays. vi. Vegetative compatibility group analysis.

Seeding symptom test: 1. Blotter test. ii. Agar test. iii. Rolled paper towel test. iv. Soil test. v.

Seedling paraquat test. vi. Bell method. vii. Plant growth medium.

Infectivity test: i. Fungi. ii. Bacteria. iii. Viruses. iv. Viroids.

Histopathological test: i. Whole seed stain. ii. Seed component. iii. Microtome seed sections. iv.

Embryo count method.

Non-destructive seed assays: i. Biopsis assay. ii. Ultrasound analysis. III. Chlorophyll

fluorescence. iv. High speed optical sorters. v. Near infrared reflectance spectroscopy (NIRS). vi.

Fourier transform infrared (FTIR) photoacoustic. vii. Computer image analysis.

Bacteriophage tests

Immunoassays: i. Precipitin test. ii. Enzyme linked immunosorbent assay (ELISA). iii. Dot-

immunobinding assay (DIBA). iv. Single antibody dot immunoassay (SADI). v. Serologically

specific electron microscopy (SSEM). vi. Immunofluorescence assay (IF). vii. Immunofluroscence

colony staining (IFC). viii. Radiommunoassays (RISA). ix. Solid phase radioimmunoassay

(SPRIA). x. Immunogold labelling. xi. Enzyme linked fluorescent assay (ELFA). xii.Disperse

dyeimmunoassay (DIA). xiii. Solid phase immunosorbent methods. xiv. Direct immunostaining

assay. xv. Vector based assays.

Nucleic acid based techniques: 1. Nucleic acid probes. ii. Restriction fragment length

polymorphisms (RFLP) analysis. iii. Polymerase chain reaction (PCR).

Electrophoresis: i. Starch get electrophoresis. ii. Polyacrylamide gel electrophoresis. iii. Isozymen

analysis.

Estimation of fungal metabolites: i. Chitin and glucosamines. ii. Ergosterol. iii. Volatile

metabolites.

Estimation of fungicides on treated seeds: i. Visual observation of seeds for dye intensity. ii.

Bioassay. iii. Colorimetric methods.

Seed Testing Services

Keeping pace with the changing needs of the seed industry, University can provide a

comprehensive variety of tests designed and integrated to meet the needs of our customers.

Standard seed testing procedures including vigor (accelerated aging and

electroconductivity), viability (standard germination and TZ), physical purity, noxious weed exams

and analysis of seed mixtures.


- 185 -

Isozyme Electrophoresis testing is a protein-based technology providing genetic purity

information for hybrid and inbred seed lots. Powerful and effective, it can accurately detect the

presence of unwanted plant types in hybrid and inbred seed lots.

Isoelectric Focusing is a highly versatile genetic purity testing method, with the ability to

evaluate proteins from many different seed and crop species. IEF technology can be used to

separate the genetics of hybrids based upon either total protein markers or various enzyme

proteins. IEF testing is a very accurate, reliable method of determining the genetic purity of a seed

lot. Once the variety testing procedures have been identified selfing and outcrossing can quickly

and accurately be detected.

To verify trait purity of genetically modified crops, ELISA (Enzyme-Linked Immuno Sorbent

Assay) technology is used to detect the presence of proteins produced by specific transgenes.

This technology allows to perform:

Qualitative tests for the presence or absence of protein

Quantitative tests to determine the level of protein expression

DNA-based technology is the most specific and sensitive method of genetic purity testing.

Using PCR (Polymerase Chain Reaction) technology, DNA detection can:

Verify the presence of valuable genes

Identify genetic contamination in seed lots

Detect and quantify adventitious presence (AP) of biotech events in seed lots or field

populations

Quantify the % sterile seeds in a seed lot

Measure the percent recurrent parent and homozygosity in backcross breeding programs

Map qualitative and quantitative traits

Determine zygosity of selected traits

Plant tissue culture: a mean of producing disease-free planting materials

Tissue culture is now being used for the mass production of plants that are reproduced

vegetatively (by cuttings), or which are difficult to grow from seed for other reasons. Seedlings

grown by tissue culture are rather expensive, compared to those grown from cuttings. However,

tissue culture has the great advantage that it can remove viruses and other pathogens, ensuring

that the seedlings are free of any disease. It is thus a good technique for producing healthy

foundation stock. Tissue culture has made possible the mass production of disease-free and

uniform plants. The technique thus brings farmers the great benefit of high-quality planting

materials of new high-value crops.

Molecular typing for genetic purity determination

Different DNA markers are available, including RFLP (restriction fragment length

polymorphism), RAPD (random amplified polymorphic DNA) and AFLP (amplified fragment length

polymorphism). These markers are used to characterize a variety or line, and in this way protect

http://www.biodiagnostics.net/seedtesting/tests.html#bytech-elisa

http://www.biodiagnostics.net/seedtesting/tests.html#bytech-elisa

http://www.biodiagnostics.net/seedtesting/tests.html#bytech-dna

http://www.biodiagnostics.net/seedtesting/tests.html#bytech-dna


- 186 -

the intellectual property rights of the plant breeder. They are also used to evaluate the purity of

seeds, and to detect genetic drift in germplasm collections. In the National Laboratory for seed

testing, the Laboratory for biotechnology runs the following tests:

verification of species and hybrids detection of genetic modification of seed and food of plant origin

Identification and determination of genetic purity of maize, sunflower, wheat, barley seeds

and seeds of other agricultural plants are done on the basis of isoenzyme and reserve proteins

according to current domestic and ISTA Rules.

Quantitative and qualitative detection of genetic modification in plant material and food of

plant origin is done using Polymerase Chain Reaction (PCR) technology. Qualitative GMO

analysis makes it possible to determine if genetic modification is present in seed or not.

Percentage of GM of soybean, maize, oil rape, potato and tomato is determined using Real Time,

and PCR method.

Disease diagnosis and molecular typing of seeds/plants is being revolutionized through the

development of DNA probes as well as antisera and monoclonal antibody (MAb) kits. With these

tools, disease detection becomes more rapid and accurate, replacing the need to culture

pathogens for identification. Besides, these tools are being used not only in seed health testing but

also identification of plant varieties.

Table 1 Attributes to be considered in selection of diagnostic method ----------------------------------------------------------------------------------------------------

1. Sampling plan

Randomization

Numbers to be drawn per predefined lot

2. Sample preparation

Non destructive diagnostic methods

Destructive diagnostic methods

Handling before examination

Transportation

Incubation

3. Biological amplification

Extraction and isolation

Culture in case of pathogens

Preparation of macerate and dilutions

Composition of extraction fluid

4. Enumeration procedure

Qualitative test

Quantitative test

5. Operation Simple, Fast, Rapid.

----------------------------------------------------------------------------------------------------


- 187 -

Table 2 Diagnostic technique developed for detection of Karnal bunt of wheat

Type of diagnostic assays techniques

Pathogenic entity Purpose

Conventional techniques

Seedling test, Blolter test, Agar test, Embryo test

Germinating Teliospores and mycelial growth

Subjective techniques for pathologists

Light microscopy Teliospores Detection and differentiation of teliospores ofTilletia sps based on morphological he dies

Epifluorescents Microscopy Teliospores Differentiation of teliospores based on emission of fluorescence

Biophysical techniques

Optical sorting Telispores in Kernels Separation of bunted grains from seed wheat

Photo acoustic spectroscopy

Teliospores mycelium Differentiation and detection based on characteristics photoaccoustic peaks and intensity of signal

Isozyme based techniques

Starch gel electrophoresis for isozyme analysis

Single teliospores mycelial cultures

Differentiation based on isozyme profiles

Nuclic acid based techniques

Bio.PCR Single teliospores mycelial cultures

Differential amplification of gene fragments

RAPD-PCR Single telisopores mycelial cultures

Differnetial RAPD profiles

Fluoragenic PCR 5 huclatide PCR assay RSPD-PCR

Single teliospore mycelial cultures

Differentiation of tilliospores

RAPD- PCR Gene tic variability amongst Tilletia indica isolates

Specific – PCR Identification of Tilletia based on amplification of species specific mitochondria DNA amplification

PCR Identification of tillletia indica

RFLP & RAPD Genetic variability amongst tilletia sps

RAPD and ribosomal DNA markers

Genetic relationship between bunt fungi

Antibody based techniques

Immunofluorescent assay Teliospores Differentiation of teliospores of bunt fungi

Microtitre ELISA Funal Mycelium Detection and quantitation of KB mycelium

Modulation of antigenicity during growth cycle

Immunopatholsing of KB isolates

Fluorescent immuno staining fest

Teliospores Detection and differential diagnosis of seed borne pathogens

Characterization of anligenic epitopes of teliospores

Dyed latex bead agglertination test

Solubilized teliospores Identification of teliospores

Immunodipstick test Intact & solublized teliospores

Do


- 188 -

Seeds: The Tale of Biotechnology

Anil Kumar and Dinesh Yadav Department of MBGE, CBSH, G.B.P.U.A.&T., Pantnagar-263145 (Uttarakhand)

“Seeds are the connection between the past and the future. They contain the accumulated genetic wisdom of the past, and the potential for its perpetuation in the future”

Seed is the most important determinant of agricultural production potential, on which

the efficacy of other agriculture inputs is dependent. Seeds of appropriate characteristics are

required to meet the demand of diverse ago-climatic conditions and intensive cropping

systems. Sustained increase in agriculture production and productivity is dependent to a

large extent, on development of new improved varieties of crops and an efficient system for

timely supply of quality seeds to farmers. The seed sector has made impressive progress

over the last three decades. There has been considerable progress in production of good

quality seeds at commercial level with the involvement of multinational companies

throughout the world. The production and distribution of seeds is a complex process

involving farmers, growers, government agencies, research institutions and other

stakeholders. The demand for hybrid seeds and transgenic seeds is also increasing based

on the added benefit of better yield and incorporation of desired traits. Seeds are the source

of life and delivery systems for agricultural biotechnology. Quality seeds are the most critical

and basic input for agricultural output, and accounts for 25-30% of yield increase. In India

80% of the farmers rely on farm-saved seeds which may results in low yield. Indian seeds

programme recognizes three kind of seed generations namely breeder, foundation and

certified seeds. There has been substantial increase in the production of foundation seeds

and distribution of quality/ certified seeds as compared to breeder seed in the recent years.

The area under certified seeds has increased from less than 500 hectares in 1962-63 to over

5 lakh hectares in 1999-2000. The quantum of quality seeds has crossed 100 lakh quintals.

The seed sector is seen as a major driver of agriculture sector in the country and is

expected to enhance the production based on increased seed replacement rate, higher

conversion, wider use of proprietary hybrids, increased farmer awareness of new methods

and introduction of technologically advance products that offer improved biotic and abiotic

traits. The commercial seed market in the country accounts for 25 per cent of the total

market potential and the remaining 75 per cent is dominated by vareital seeds that farmers

retain from prominent food and commercial crops. Seed quality is an important consideration

in agricultural practices and needs to be evaluated for better production. Seed quality is a

complex trait being influenced by interaction of numerous genetic and environmental factors.

High quality seed leads to excellent seedling performance in the field and is need of the

hour. Conventional plant breeding approach in combination with modern biotechnological


- 189 -

tools can enhance physiological quality, vigor and synchronity of seeds to establish a crop in the

field under diverse environmental conditions.

Varietal identification: A core issue in seed production

Conventionally identification of any cultivar has relied on morphological markers, which

requires a detailed study of seeds and or growing plants and the observation recording and

analysis of a number of morphological characters. However, these methods are subjective and

may be influenced by environmental conditions. Further these markers were not quite enough to

expose the genetic diversity between the morphological overlap cultivars and the morphological

identical accessions. The need, therefore, for new method such as molecular methods was

disparate. These methods are independent of cultivar morphology and physiology, and offer

significant advantages over morphological methods of variety and/or species identification in that

they are rapid, relatively cheap, eliminate the need to grow plants to maturity and are largely

unaffected by the growing environment.

Molecular methods for variety identification can be divided in to two classes: 1. Protein based methods and 2. DNA based methods

Because of the increased emphasis on quality of food product for specific purposes, there

is a need for development of methods which ensure quality assurance, variety identity

preservation, seed purity and product traceability. Exporters, importers and consumers globally are

demanding higher quality products, including specific varieties of grain for specific purposes.

Hence, with the advent of new technology, stricter quality control and international competition, the

importance of efficient varietal identification techniques can not be neglected. Varietal identification

techniques are also required for enforcement of Intellectual property rights and resolution of

controversial issues related with the use of patented variety and introduction of a variety for

commercial production. Varietal identification is required for discrimination of various crop varieties

of agriculture and horticulture and is crucial from seed technology view point. For example, it is

essential for maintenance of plant breeders rights, and implementation of rigid standards for

varietal identity and purity. Varietal identification techniques are also important to check hybridity of

the cultivars which is essential to detect if varieties are segregating or not.

Seed quality improvement

Seed technologies include priming, pelleting, coating, artificial seeds, and other novel seed

treatment methods for quality improvement. Seed germination is controlled by environmental

factors (light, temperature, water) and on plant hormones as endogenous regulators (gibberellins,

abscisic acid, ethylene, auxin, cytokinins, brassinosteroids). The utilization of plant hormones and

inhibitors of their biosynthesis and action in seed treatment technologies affects seed germination

and seedling emergence. The genes, enzymes, signaling components and down-stream targets of

plant hormones provide molecular marker for seed quality and seedling performance.

Various mechanical techniques like polishing off or rubbing off seed coat (testa) or fruit

coat (pericarp) projections or hairs and seed sorting by sizes and seed density can contribute to


- 190 -

the seed quality assurance. Different methods can be used to enhance seeds and seedling

performances namely

i) Film-coating methods: It allows the chemicals to be applied in a synthetic polymer that is

sprayed onto the seeds and provide a solid, thin coat covering them. The advantage of the

polymers is that they adhere tightly to the seed and prevent loss of active materials like fungicides,

nutrients, colorants or plant hormones. Some novel applications of film coating are used to modify

imbibitions and germination. They can confer temperature-sensitive water permeability to seeds or

affect gaseous exchange. By this they control the timing of seed germination and seedling

emergence.

ii) Seed pelleting methods: This adds thicker artificial coverings to seeds, which can be used to

cover irregular seed shapes and add chemicals to the pellet matrix, e.g. of sugar beet or vegetable

seeds. The pellet matrix consists of filling materials and glue. Loam, starch, tyllose (cellulose

derivative) or polyacrylate/polyacrylamide polymers are commercially used. Seed pelleting is also

used to increase the size of very small horticultural seeds. This provides improved planting

features, e.g. singulate planting, the use of planting machines, or precise placement and visibility

in/on the soil.

iii) Seed Priming methods: It is the most important physiological seed enhancement method.

Seed priming is a hydration treatment that allows controlled imbibition and induction of the pre-

germinative metabolism ("activation"), but radicle emergence is prevented. The hydration

treatment is stopped before desiccation tolerance is lost. An important problem is to stop the

priming process in the right moment; this time depends on the species and the seed batch.

Molecular marker can be used to control the priming process. Priming solutions can be

supplemented with plant hormones or beneficial microorganisms. The seeds can be dried back for

storage, distribution and planting. Germination speed and synchrony of primed seeds are

enhanced and can be interpreted in the way that priming increases seed vigor. A wider

temperature range for germination, release of dormancy and faster emergence of uniform

seedlings is achieved. This leads to better crop stands and higher yields. A practical drawback of

primed seeds is often a decrease in storability and the need for cool storage temperatures.

Several types of priming viz. Osmopriming, Hydropriming and Matrixpriming are commonly used.

i) Osmopriming (osmoconditioning) is the standard priming technique. Seeds are incubated in

well aerated solutions with a low water potential, and afterwards washes and dried. The low water

potential of the solutions can be achieved by adding osmotica like mannitol, polyethyleneglycol

(PEG) or salts like KCl.

ii) Hydropriming (drum priming) is achieved by continuous or successive addition of a limited

amount of water to the seeds. A drum is used for this purpose and the water can also be applied

by humid air. 'On-farm steeping' is the cheep and useful technique that is practiced by incubating

seeds (cereals, legumes) for a limited time in warm water.


- 191 -

iii) Matrixpriming (matriconditioning) is the incubation of seeds in a solid, insoluble matrix

(vermiculite, diatomaceous earth, cross-linked highly water-absorbent polymers) with a limited

amount of water. This method confers a slow imbibition.

Hybrid seeds production:

The contribution of agriculture to the national economy has been constantly declining

45.2% to 21% during 2005-06 in India. The challenge is to increase productivity in the scenario of

reducing/ stagnant resources of land and water, and significant losses due to several biotic and

abiotic stresses. Hybrid seed technology can contribute to the overall productivity once used

judiciously.

The successful development and use of hybrid rice technology in china during 1970’s led

the way for development and release of rice hybrid varieties elsewhere. India has made good

progress in this regard and numbers of hybrid varieties of rice are being used by the farmers.

Hybrid-rice can be produced in the following ways.

1. Three-line system: The hybrid seed production involves multiplication of cytoplasmic-

genetic male sterile line(A line), maintainer line (B line) and a restorer line (R line); and

production of F1 hybrid seed (AxR)

2. Two-line system: The hybrid seed production involves the use of photo-period sensitive

genetic male steriles (PSMS). Any normal line can serve as a restorer.

3. By using chemical emasculators: Chemicals that can sterilize the stamen, with little or no

effect on the normal functioning of the pistil, can be used to emasculate female parents for

hybrid rice production. The advantages are obvious, no special development of male

sterile or restorer lines is required, and extensive varietal resources are available.

Chemical emasculators such as male gametocie 1(MF1) and male gametocie 2(MG2) were

developed in China and have been successfully used in hybrid rice production. In chemical

emascultion, physiological male sterility is artificially created by spraying the rice plant with

chemicals to induce stamen sterility without harming the pistil. In hybrid seed production,

two varieties are planted in alternate strips, and one is chemically sterilized and pollinated

by the other.

Artificial seeds production:

Cell culture and regeneration techniques allow the mass production of somatic embryos,

which can subsequently be packed in a suitable gel-type matrix (agar- agar, gums, dextrans) and

covered with artificial seed coat and are referred as artificial seeds. This can be used to generate

genetically identical seedlings of poplar, orchids and other species. Further it can be used as an

important packaging system.

Biotechnological interventions in quality seed production

Although conventional plant breeding methods have led to development of crop varieties

which eventually resulted in sustained increase in crop productivity, they are now superseded by

selection procedures based on modern biotechnological tools such as marker assisted selection


- 192 -

and genetic engineering to transfer relevant genes in to our crops. Modern biotechnological

methods have enabled to unravel the molecular basis of a trait which has led to identification of

candidate genes/proteins. Genetic engineering has potential to transfer these important candidate

gene/protein across the species which is otherwise not possible by conventional plant breeding

methods. As a result of this complementation superior crop varieties are now being generated

which are highly productive, nutritive and tolerant to various biotic and abiotic stresses as well cost

effective both for consumers and farmers.

Biotechnology will be a key factor in development in the coming decades. Genetic

engineering/modification techniques hold enormous promise in developing crop varieties with a

higher level of tolerance to biotic, abiotic stress and insect resistance (BT). Some genes usually

confer resistance to herbicides, insects, pests and resistance to draught and salinity. This provides

strength to harness useful genes for developing plant types with in-built resistance for biotic and

abiotic stresses and improved nutritional quality. A conducive atmosphere for application of frontier

sciences in varietals development and for enhanced investments in research and development is a

pressing requirement. At the same time, concerns relating to possible harm to human health and

bio-safety as well as interests of farmers, must be addressed.

Genetically modified seeds

Modern biotechnology has introduced new agricultural products based on the precise

recombinant DNA technology incorporating the desired gene with important agronomical traits in

the recent years. The introduction of genetically modified Bollgard cotton seeds containing a

protein from soil microbe called Bacillus thuringiensis (Bt), which protects the crop from bollworms

and requires less pesticides has been a successful story in India. India's average per-hectare

yield has risen by two-thirds to 501 kg since farmers started planting GM seeds in 2002.

In 2004, the global area of transgenic crops continued to grow for the eight consecutive

years at a sustained growth rate and was found to approx 83 million hectares in year 2004

compared with 67.7 million hectares in 2003. Of six leading GM crop countries (USA, Argentina,

Canada, Brazil, China and South Africa), China and South Africa had the highest year to year

increase with approx. 40% growth rate. China increased its Bt cotton area for the sixth consecutive

year. The US$ 2.5 billion GM seed market is dominated by a single corporation that sells GM

seeds for four major crop commodities (soybean, maize, cotton, canola) in three countries (USA,

Argentina and Canada). The expansion in this direction could include possibilities such as:

1. The application of GM technology to a wider range of crop types giving improved yield and

quality.

2. A range of more valuable agronomic traits, such as resistance to common pests or

improvements in the efficiency with which crops can assimilate nutrients.

3. GM foods with consumer benefits, such as longer shelf life, or health benefits, such as

improved nutritional content or reduced allergenicity.


- 193 -

4. A wide range of non-food crops, which could include the production of pharmaceuticals,

industrial oils, renewable materials and crops which could be used directly in the

production of energy and fuel. Production for fuel could become increasingly attractive in

the event of more favorable revenue conditions applying to bio-fuels.

The GM seed market represents about 10% of the commercial seed market worldwide.

The total GM seed market in India has an estimated value of US$25 million. India increased its BT

cotton area by 100%; India placed 8th partition with 0.1 million hectares production. GEAC has

approved the commercialized cultivation of BT cotton in April 2002 in six states in the country,

which include Maharashtra, Gujarat, M.P., A.P., Tamil Nadu and Karnataka. Other crops such as

mustard, soybean corn and potatoes are expected to receive approval in the near future. The GM

seeds segment in India is dominated by various companies such as Mahyco, Monrto, ProAgro,

Aduantor, Mahyco Monsanto.

Biotechnological tool for maintenance of hybridity

Barnase-barstar system : Gene barnase encodes an RNAse which kills the cells in which it is

expressed by degrading RNA. The expression of barnase was confined to tapetal cells by fusing it

with the promoter of tobacco tapetum specific gene TA29 ( gene construct : pTA29- barnase; p

promoter ). When the chimaeric gene construct was transferred and expressed in tobacco and

oilseed rape, the tapetal cells of anthers were destroyed and there was no pollen development.

However there was no effect on female fertility. Since the male sterility due to barnase is

dominant, the male sterile lines are always heterozygous (barnase/- ; the – sign indicates absence

of barnase gene in homologous chromosome) and they have to be maintained by crossing to any

normal, non transformed male fertile line (-/-; barnase gene absent). Thus male sterile lines (

barnase/-) will have to be crossed to be normal fertile lines (-/-), and only 50% of the progeny from

such crosses will be male sterile while rest 50% will be male fertile (-/-). In a hybrid seed

production programme the male fertile plants present in male sterile line must be identified and

easily eliminated. This has been done by linking the barnase gene with the bar gene from

Streptomyces: bar gene confers resistance to herbicide phosphinothricin. When such male sterile (

barnase-bar/-) plants are maintained by crossing with normal male fertile (-/-), all the male sterile

progeny ( barnase-bar/- ) are resistant to the herbicide, while all the male fertile plants (-/-) are

herbicide susceptible. The male fertile plants are therefore eliminated by a herbicide spray at an

early stage of plant growth.

The male fertility of barnase male steriles is restored by another gene, barstar, of the

bacterium B. amyloliquefaciens. The gene barstar encodes a specific inhibitor of barnase encoded

RNase. The barstar product forms a highly stable 1:1 non-covalently bound complex with the barnase

RNase; this reaction provides protection to the bacterial cells from their own RNase product.

Transgenic plants expressing barstar are male fertile without any phenotypic effect, and are easily

maintained in the homozygous state. When a homozygous barstar male fertile line is crossed with a

barnase male sterile all the progeny plants are male fertile since barstar gene product effectively


- 194 -

inhibits the barnase RNAse in barnase-bar/barstar plants. This male sterility/fertility system has shown

commercial promise in maize and oilseed rape and can be easily extended to other crop species.

Seeds as target for molecular farming:

One of the emerging fields of plant biotechnology, referred to as “Molecular Farming”, has

been used in recent years to produce value-added products for nutraceuticals, pharmaceuticals,

and other industrial applications. Molecular farming is defined as the production of proteins or

other metabolites valuable to medicine or industry in plants traditionally used in an agricultural

setting. The concept of using plants as hosts for the production of valuable proteins has been

called "molecular farming". A wide range of pharmacologically interesting proteins can be

expressed in diverse plant organs and seeds can be one important host. This has as an

advantage that these transgenic seeds harboring the protein of interest can be stored in the dry

state for a long time and the integrity of the pharmacologically interesting protein is kept. Modified

seeds storage proteins and modified oleosin proteins have been used for this purpose.

The accumulation of recombinant antibodies in seeds allows long-term storage at ambient

temperatures because the proteins amass in a stable form. Seeds have the appropriate

biochemical environment for protein accumulation, and achieve this through the creation of

specialized storage compartments, such as protein bodies and storage vacuoles, which are

derived from the secretory pathway. Seeds are also desiccated, which reduces the exposure of

stored proteins to non enzymatic hydrolysis and protease degradation. Cereal seeds also lack the

phenolic substances that are present in tobacco leaves, so increasing the efficiency of

downstream processing. Maize is now the main commercial production crop for recombinant

proteins, which reflects advantages such as high biomass yield, ease of transformation and in vitro

manipulation, and ease of scale-up. Maize is also being used for the production of recombinant

antibodies and further technical/pharmaceutical enzymes, such as laccase, trypsin and aprotinin.

The use of barley grains as bioreactors for highly active and thermo-tolerant hybrid cellulase (1,4-

ßglucanase) was investigated .

Alfalfa and soybean produce lower amounts of leaf biomass than tobacco, but have the

advantage of using atmospheric nitrogen through nitrogen fixation, thereby reducing the need for

chemical inputs. Both species have been used to produce recombinant antibodies. Pea is being

developed as a production system, although at present the yields that are possible with this

species are low.

Seed storage proteins as target for nutritional quality improvements and

development of nutraceuticals

In general, cereal seed storage proteins are low in lysine and tryptophan while legumes are

deficient in the sulfur containing amino acids, methionine and cysteine and hence can be

considered as nutritionally poor. Biotechnological approach for improving seed storage protein

quality can be i) protein sequence modification ii) synthetic genes iii) overexpression of

homologous genes and iv) Transfer and expression of heterologous genes. In order to establish

ragi as nutraceutical crop, value added products for diabetics, pregnant women and children in the

form of breakfast and meals can be prepared based on the scientific rationale explored in our lab.


- 195 -

New Approaches to Pest Risk Analysis for Quarantine Pests

(Mrs.) Ruchira Tiwari Department of Entomology, G.B.P.U.A.&T., Pantnagar-263145 (Uttarakhand)

What is Pest Risk Analysis (PRA)

Pest Risk analysis is a process of investigation, evaluation of information and decision

making with respect to a certain pest, that starts once it is known or determined that this pest is a

quarantine pest. Subsequently, an evaluation of the potential of introduction of the pest into the

country is done along with its economic, social and environmental consequences. With

identification, determination and evaluation done, the process culminates with decision making to

avoid or reduce the probability of entrance or establishment of the pest into the country.

There are generally two initiation points for a PRA:

The identification of a pathway, usually an imported commodity, that may allow the

introduction and/or spread of quarantine pests

The identification of a pest that may qualify as a quarantine pest

The review or revision of phytosanitary policies and priorities.

The PRA process as described in the International Standards For Phytosanitary Measures

(ISPM) is divided into four phases –Pest risk initiation, Pest risk assessment, Pest risk

management and Pest risk communication/documentation.

General Requirements for Pest Risk Analysis (Pra)

Phase 1: Pest Risk Initiation

The initiation phase begins with the identification of the pest. In the PRA process, for

access of a commodity such as a fruit, a seed or a grain, the specific commodity has to be

identified botanically and the parts of the plant that form this commodity have to be determined.

Once this is completed, a list of pests in the country of import and export, can be prepared.

There are generally three initiation points for a pest risk analysis (see Figure 1):

1. PRA Initiated by a Pathway

A requirement for a new or revised PRA originating from a specific pathway will

most frequently arise in the following situations:

- International trade is initiated in a new commodity (usually a plant or plant product) or a

commodity from a new origin.

- New plant species are imported for selection and scientific research purposes.

- A pathway other than commodity import is identified (natural spread, mail, garbage,

passenger's baggage etc.).

- A policy decision is taken to establish or revise phytosanitary regulations or

- requirements concerning specific commodities.

- A new treatment, system or process, or new information impacts on an earlier decision.


- 196 -

- The pests which are likely to follow the pathway (e.g. be carried by the commodity) are

then listed, and each is then subjected to Stage 2 in the PRA process. If no potential

quarantine pests are identified as likely to follow the pathway, the PRA stops at this point.

2. PRA Initiated by a Pest

A requirement for a new or revised PRA originating from a specific pest will most

frequently arise in the following situations:

- An emergency arises on discovery of an established infestation or an outbreak of a new

pest within a PRA area.

- An emergency arises on interception of a new pest on an imported commodity.

- A new pest risk is identified by scientific research.

- A pest is introduced into a new area other than the PRA area.

- A pest is reported to be more damaging in a new area other than the PRA area itself, than

in its area of origin.

- Audits reveal that a particular pest is repeatedly intercepted.

3. PRA initiated by the review or revision of a policy

A requirement for a new or revised PRA originating from policy concerns will most

frequently arise in the following situations:

- A national decision is taken to review phytosanitary regulations, requirements or operations

- A proposal made by another country or by an international organization (RPPO, FAO) is

reviewed

- A new treatment or loss of a treatment system, a new process, or new information impacts

on an earlier decision

- A dispute arises on phytosanitary measures

- The phytosanitary situation in a country changes, a new country is created, or political

boundaries have changed.

The specific pest identified is then subjected to Stage 2 in the PRA process.

Phase 2. : Pest Risk Assessment

After Stage 1, a pest, or list of pests (in the case of initiation by a pathway),are identified

which are to be subjected to risk assessment. Stage 2 considers these pests individually (see

Figure 2). It examines, for each, whether the criteria for quarantine pest status are satisfied or not:

Quarantine pests- "a pest of potential economic importance to the area endangered thereby

and not yet present there, or present but not widely distributed and being

officially controlled".

In this context, "area" should be "an officially defined country, part of a country, or all or part

of several countries", and "endangered area" should be "an area where ecological factors

favour the establishment of a pest whose presence in the area will result in economically

important loss".


- 197 -

In doing so, the PRA considers all aspects of each pest and in particular actual information

about its geographical distribution, biology and economic importance. Expert judgment is then

used to assess the establishment, spread and economic importance potential in the PRA area.

Finally, the potential for introduction into the PRA area is characterized.

1. Economic Importance Criteria

For potential economic importance to be expressed, a pest must become established and

spread. Thus the risk of a pest, having entered, becoming established and spreading in the PRA

area must be characterized. The factors to be considered are set out below.

a. Establishment potential

In order to estimate the establishment potential of a pest, reliable biological information (life

cycle, host range, epidemiology, survival etc.) should be obtained from the areas where the pest

currently occurs. Examples of the factors to consider are:

- availability, quantity and distribution of hosts in the PRA area

- environmental suitability in the PRA area

- potential for adaptation of the pest

- reproductive strategy of the pest

- method of pest survival.

If a pest has no potential for establishment in the PRA area, then it does not satisfy the

definition of a quarantine pest and the PRA for the pest stops at this point.

2. Spread potential after establishment

In order to estimate spread potential of the pest, reliable, biological information should be

obtained from areas where the pest currently occurs.

Examples of the factors to consider are:

- suitability of the natural and/or managed environment for natural spread of the pest

- movement with commodities or conveyances

- intended use of the commodity

- potential vectors of the pest in the PRA area

- potential natural enemies of the pest in the PRA area.

The information on spread potential is used to estimate how rapidly a pest's potential

economic importance may be expressed within the PRA area. This also has significance if the pest

is liable to enter and establish in an area of low potential economic importance and then spread to

an area of high potential economic importance. In addition it may be important in the risk

management stage (see Figure 3) when considering the ease with which an introduced pest could

be contained or eradicated.

3. Potential economic importance

The next step in the PRA process is to determine whether the pest is of potential economic

importance in the PRA area. In order to estimate the potential economic importance of the pest,

information should be obtained from areas where the pest currently occurs. For each of these


- 198 -

areas, note whether the pest causes major, minor or no damage. Note whether the pest causes

damage frequently or infrequently. Relate this, if possible, to biotic and abiotic effects, particularly

climate. The situation in the PRA area can then be carefully compared with that in the areas where

the pest currently occurs.

Examples of the factors to consider are:

- type of damage

- crop losses

- loss of export markets

- increases in control costs

- effects on ongoing integrated pest management (IPM) programmes

- environmental damage

- capacity to act as a vector for other pests

- perceived social costs such as unemployment.

If a pest has no potential economic importance in the PRA area, then it does not satisfy the

definition of a quarantine pest and the PRA for the pest stops at this point.

4. Introduction Potential

The final stage of assessment concerns the introduction potential which depends on the

pathways from the exporting country to the destination, and the frequency and

quantity of pests associated with them. Documented pathways for the pest to enter new areas

should be noted. Potential pathways which may not currently exist should be assessed if known.

The following is a partial checklist that may be used to estimate the introduction potential divided

into those factors which may affect the likelihood of entry and those factors which may affect the

likelihood of establishment.

Entry

- opportunity for contamination of commodities or conveyances by the pest

- survival of the pest under the environmental conditions of transport

- ease or difficulty of detecting the pest at entry inspection

- frequency and quantity of pest movement into the PRA area by natural means

- frequency and number of persons entering from another country at any given port of

entry.

Establishment:

- number and frequency of consignments of the commodity

- number of individuals of a given pest associated with the means of conveyance

- intended use of the commodity

- environmental conditions and availability of hosts at the destination and during

transport in the PRA area.

Conclusion for Stage 2


- 199 -

If the pest satisfies the definition of a quarantine pest, expert judgement should be used to

review the information collected during Stage 2 to decide whether the pest has sufficient economic

importance and introduction potential, i.e. sufficient risk, for phytosanitary measures to be justified.

If so, proceed to Stage 3; if not, the PRA for the pest stops at this point3.

Phase 3: Pest Risk Management

Pest risk management (see Figure 3) to protect the endangered areas should be

proportional to the risk identified in the pest risk assessment. In most respects it can be based on

the information gathered in the pest risk assessment. Phytosanitary measures should be applied

to the minimum area necessary for the effective protection of the endangered area.

1. Risk Management Options

A list of options for reducing risks to an acceptable level should be assembled. These

options will primarily concern pathways and in particular the conditions for permitting entry of

commodities. Examples of the options to consider are:

- inclusion in list of prohibited pests

- phytosanitary inspection and certification prior to export

- definition of requirements to be satisfied before export (e.g. treatment, origin from pest free

area, growing season inspection, certification scheme).

- inspection at entry

- treatment at point of entry, inspection station or, if appropriate, at place of destination

- detention in post-entry quarantine

- post-entry measures (restrictions on use of commodity, control measures)

- prohibition of entry of specific commodities from specific origins.

2. Efficacy and Impact of the Options

The efficacy and impact of the various options in reducing risk to an acceptable level

should be evaluated, in terms of the following factors:

- biological effectiveness

- cost/benefit of implementation

- impact on existing regulations

- commercial impact

- social impact

- phytosanitary policy considerations

- time to implement a new regulation

- efficacy of option against other quarantine pests

- environmental impact.

In order to determine which options are appropriate, it may be advisable to communicate with

interested and affected groups within and outside the PRA area.

Conclusion for Stage 3

At the end of Stage 3, the appropriate phytosanitary measures concerning the pest


- 200 -

or pathway should be decided. Completion of Stage 3 is essential; it is in particular not justified to

complete only Stages 1 and 2 and then take phytosanitary measures without proper assessment

of risk management options. After implementation of the phytosanitary measures, their

effectiveness should be monitored and the risk management options should be reviewed, if

necessary.

4. Documenting THE Pra Process

A PRA should be sufficiently documented so that when a review or a dispute arises, the

PRA will clearly state the sources of information and the rationales used in reaching a

management decision regarding phytosanitary measures taken or to be taken. The main elements

of documentation are:

- purpose for the PRA,- pest, pest list, pathways, PRA area, endangered area,- sources of

information,- categorized pest list, conclusions of risk assessment, probability, consequences, risk

management, options identified, options selected

Necessary Information on a Product which is to be subjected to the PRA pocess

1. Scientific name, genus, species and family of the plant, product or by-product of interest.

2. Localization, altitude, and latitude of the areas of production designated to exportation in

the country of origin.

3. Map of the country showing the areas of production designated to exportation and other

areas.

4. Climatical conditions in the areas of production

- Maximum and minimum temperatures

- Level of precipitation

- Predominant winds

- Relative humidity

5. Phenology of the crop, emphasizing the most important phases of growth according to the

use and destiny of the product: leaf development, flowering and fructification

6. Phytosanitary management of the crop, showing dates and stages of major pest

incidences.

7. List of quarantine pests by stages of development of the crop, emphasizing the important

pests related to the part of the plant which is being imported

8. List of pests of quarantine importance according to the A1 and A2 pest lists both of the

importing and exporting country.

9. Biology, and actual situation, distribution, economic damage of the important quarantine

pests in the production zone designated for export

- A1 Pest list- list of quarantine pests associated with the plant product which are not

present in the importing country


- 201 -

- A2 Pest List- list of pest of quarantine importance associated with the product found

only in parts of the importing country and are subjected to official control

10. Pre and post harvest phytosanitary treatments for important quarantine pests.

11. Interior phytosanitary regulations of the exporting country related to the crop of interest, or

pests identified as quarantine pests if such regulations are present in the country .

12. Vigilance and monitoring systems to prevent the outbreak of pests of quarantine

importance if such systems are present in the country.

13. Infrastructure for the application of recognized quarantine treatments for the pests of

quarantine importance.

14. Volumes of production and exportation

15. List of natural enemies of the pests of quarantine importance, if they exist in the exporting

country related to the plant, product or byproduct of interest.

Figure 1

PEST RISK ANALYSIS

Stage 1: Initiation

Identify

pathway Identify

pest

Valid

earlier

analysis?

Valid

earlier

analysis?

Potential

quarantine pests

identified?

Potential

quarantine

pest

STOP Yes

STOP Yes

STOP no

no no

GO TO STAGE 2

Yes


- 202 -

no

Figure 2

PEST RISK ANALYSIS

Stage 2: Assessment

Potential

quarantine pest

Present in

PRA area?

Area

suitable for

establishment?

Limited

distribution?

Will have

economic

importance?

Already

under official

control?

Has economic

importance?

Has economic

importance?

Put under

official control

STOP

no yes

yes

yes

no

yes

no no

yes

STOP yes

yes

Quarantine

pest

Evaluate

introduction

potential

GO TO STAGE-3


- 203 -

Figure 3

PEST RISK ANALYSIS

Stage 3: Management from stage 2

Generate, evaluate

and compare

management options

Select option

Monitor and

evaluate after

implementation


- 204 -

Communication Skills for Teaching

B. Kumar Department of Agriculture Communication, G.B.P.U.A.&T., Pantnagar-263145 (Uttarakhand)

What is so sacred about teaching. Anybody with educational qualification feels qualified to

teach. Teaching is not same as lecturing or preaching. It is not simply telling facts. Effective

teaching is orderly, businesslike and focused on learning outcome.All good teachers approach

teaching systematically and at the level of the learners. Learning is different among individuals.

Teachers must understand learners’ interests experiences and needs. Effective teaching is

motivating and pleasant experience.

What is teaching?

Learners do not have empty minds. They have experiences, habits and presumptions. So teaching is stimulating them to absorb. It requires more then more knowledge of the subject.A good teacher must know his subject thoroughly. He should understand the learners, psychology and level of learning besides, a must have knowledge and skills in methods of teaching. In order to teach someone effectively a personal report is needed. Thus, teacher must be skilled in communication.

An Expert Highly Commented that Teaching is the technique or better still the art which enables use to proceed from merely knowing to “making known”. A gift for teaching is possession of a dynamic force which brings out an inner store of knowledge. It is the force which enlivens knowledge and give the capacity is art of making others understand what we have understood ourselves.

Thus, the focus of teaching is not merely on scholarship or expertise but also the technique of communication through which learners can be motivated to learn. Such a technique can come form in-depth observation of learner and the way they learn. All individuals differ in learning. So the teaching must provide variable learning solutions.

Such a knowledge in case of agricultural education is not only the critical but practical and related to field problem. Thus, the teacher must have sufficient fields experience to understand the solutions. He should know how to organize learning experience to choice desire learning outcome. It is thus, clear that teaching requires special understanding about the ways and means to make others learn.

Pattern Of Effective Teaching

Various researches an teaching have concluded some common pattern about teaching as given below:

Clarity: Effective teaching is simple and clear. It is easy for learners to understand and apply.

Teachers relate topic to the experiences and level of understanding of learners. They employ

example and analogies to clarify the subject.

Variability: good teaching has Varity. Varity comes from audio-visuals stimuli used by

teachers. If a teacher talks continuously in the same tone, learners get bored. A teacher may

vary volume, he may use visuals. He may shift from lecturing to getting inputs of learners.

Various Sources Of Variability In The Classroom May Be:

Speaking to writing/drawing.

Chang in volume

Change in pace of speaking


- 205 -

Shift from teacher talk to student talk

Shift from listing only to solving problem

Shift in movement from podium to classroom

Enthusiasm: Enthusiasm is contagious. It effects others. If teacher is full of enthusiasm about

the subject he may communicate to students in no uncertain term. Students feel motivated. It

has been a common of effective teacher.

Business Like Behaviour: an effective teacher is a professional. He plans his lesson,

approaches class in step by step manner to loads to the learning outcome. He should begin

and end class in time. He should use audio-visual aids and verity of teaching methods

appropriate to the subject and learners.

Recommendation: thus, some of the general practices recommendations for making effective

are as below:

Plan Your Teaching: well in advance no matter how experienced and adept you are in the

subject, you must organize your lesson step by step from beginning to end. It is better to

develop the sequence of teaching in the beginning of semester. So that audio-visual aids,

hands-out, exercises and assignments can be detailed before hand.

Maintain A Positive Atmosphere: classrooms are not meant for perching and controlling.

Students in higher education are adults. They must be respected and treated with care. Know

students by name. involve in classroom instruction and know their special talents. Knowing

them, giving them praise and solving their problems helps in creating positive relationship.

Involve Students In The Class: learning is enhanced if students are octively involved. In

order to involve students, ask for their inputs form time to time a sense of learnership. You may

pose a practical problem and seek their views. Involve students in discussion.

Use Various Sense: learning is best when different senses re used. Apart from lectures plan

visits, practical season, discussion and seminars to create interest. It is common in

professional subjects to assign project related with topic to help students work independently.

Lead to Higher of Learning: learning fats by memorizing is not enough. Professional

subjects like agriculture is meant for problem solving. Students must discuss and solve

problems and analysis cases to develop.

Through Understanding: become an experiment list in teaching to test various methods and

approaches and know that works better .

Some Do’s

Focus on concrete learning outcome. Make it pleasant experience.

Involve learners

Instill in them a desire to learn

Manage time effectively

Praise good work


- 206 -

Supervise learning closely

Some Don’ts

Know students as persons

Do not use enviroment as substitute to teaching.

You may pass time with humour but it will be liked by lazier section of the class. All will

know the game you are playing.

Do not favour a particular section of class over other.

Teachers may have own basis. Mostly we focus more attention as those who respond

frequently. The other section feels neglated. Be discreet in asking questions or assigning roles.

Do not over use examples from your own life.

If you always quote examples from your travel abroad or hard work students may make fun of it

and the story will pass generation to generation.

Do not give blind assignments

Assignments must be based on the lesson objective and be feasible. Giving a reading assignment

to 30 students when only three confess of the related title is available in library is not proper.

Students know its value.

Do not make class a prison want

A certain amount of discipline is required to conduct class effectively but too much of it makes the

class dull and boring. Do not try to control them unnecessarily by rules.

Finally teaching is facilitating the process of learning by motivating the students, creating

conducive environment, organizing subject matter systematically and providing meaningful

experience. Good teaching influences and moulds behaviour. To facilitate, is to help something

(usually a process) move along. The word derives from "facile" which is French for "easy". To

facilitate, them, is to make something easier. Through facilitation, the instructor provides boosts

to participants through a series of experiences to create a desired effect. Facilitate does not mean

"solving a problem" or "doing it for someone". It means doing something that makes a process run

a little better. . However, facilitation can also be understood to mean all the behaviors, which

influence the experience of the individuals and the group.


- 207 -

Seed Health Management in Potato

V.S. Pundhir Department of Plant Pathology, G.B.P.U.A.&T., Pantnagar-263145 (Uttarakhand)

Potato is a wonder crop that can grow under diverse range if conditions (650 N to 470S). It

is being cultivated in 149 countries with annual production of 320 million tones. Indo-China

produces about 30% of this. Over one billion people eat potato. Short duration, high yield per unit

area and time and wide flexibility in planting and harvesting time are important virtues of potato

that enable its inclusion in intensive cropping system. Realizing potato as the potential food of

future, United Nation has identified year 2008 as “International Potato Year”. It is being identified

as the crop that can fill the cereal deficit, thus a God’s blessing to poor people. Potato produces in

one hectare what cereals will produce in 2-4 hectares. In addition, 85% of potato crop is edible

while in case of cereals it is only 50%.

Potato was introduced in India in 17th century by Portuguese and by 1931 it became an

established crop in cooler regions of countries. Organized research on potato started by

establishment of Central Potato Institute (Patna / Shimla) in 1949. Further, All India Coordinated

potato Improvement Project (AICPIP) was initiated in 1970. In India 82% area is under plains (Oct.

March, winter), 10% area in plateau (Peninsular India: Summer/ autumn) and 8% area is in hills

(summer long day Feb – October). CPRI has released total 41 cvs. (1958) of these 25 are for short

duration (plain). In

1998 first industrial / processing cv, Chipsona -1 was released, after that Chipsona -2 &

Chipsona -3 has also come. Total seed requirement in India is 4.2 – 5.25 mt. In India 2500 tones

of BS is produced which undergoes in seed production channel (Certified-1, Certified-2,

Foundation-1 and Foundation-2). India in not only self sufficient for seed required but can also

export quality seed.

During 1952 Survey of potato growing areas was initiated and it was found that in N-W and

Central Indo-Gangatic Plains aphid population was very low in October – December (20

aphids/100 compared leaves). Thus quality potato seed can be produced. In 1959: Seed Plot

Technique was developed at CPRI, with conditions that 75 aphid free days were available for

production of healthy Seed under low aphid population with use of insecticide. Dehaulming is to be

done in Jan 2nd week (no re-groth is permitted and an isolation of 25m from ware crop. Following

were the impact of SPT:

Quality Seed production on large area

Seed of right Physiological State

Soil-borne pathogen of hills not carried


- 208 -

Problems related with potato seed:

POTATO VIRUSES

(a) Diseases caused by fungal pathogen

Disease Fungal Pathogen

Late Blight Phytophthora infestans

Powdery Scab Spongospora subterranea

Black Scurf Rhizoctonia solani

Charcoal Rot Macrophomina phaseolina

Fusarium Wilt Fusarium oxysporum

Verticillium Wilt Verticillium spp.

Dry Rot Fusarium sambucinum

Silver Scurf Helminthosporium solani

Pink Rot Phytophthora erythroseptica

Leak Pythium spp.

Black Dot Colletotrichum atramentarium

Gangrene Phoma exigua var. exigua

Wart Synchytrium endobioticum

(b) Diseases caused by bacterial pathogen

Disease Bacterial Pathogen

Common Scab Streptomyces scabies

Bacterial Wilt or Brown Rot Ralstonia solanacearum

Black Leg Erwinia caratovora var. atroseptica

Soft Rot Erwinia caratovora var. caratovora

Ring Rot Clavibacter michiganensis sub sp. sepedonicus

Pink Eye Pseudomonas marginalia

(c) Mechanical and physiological disorders

Disease Bacterial Pathogen

Cracking Bruises, cuts and deep abrasions

Greening Exposure to sunlight

Black heart Low oxygen level in the interior of the tuber

Hollow heart Over fertilization, high soil moisture

Black spot Pressure bruising

Permissible limits of purity and diseases in crops

Grade of seed

% plants infected with

Off type

Mild mosaic

Severe mosaic PLRV, PVY, yellows

Total viruses

Brown rot PSTV

FS-I 0.05 1.0 0.5 1.0 - -

FS-II 0.05 2.0 0.75 2.0 3 pl/ha -

Certified 0.10 3.0 1.0 3.0 3 pl/ha -

Permissible limits of seed tuber damages and diseases

Grade of seed

% incidence of tuber borne diseases

Common scab Black scurf Cut/bruised LB Dry rot Total disease

FS-I 5.0 5.0 1.0 1.0 1.0 5.0*

FS-II 5.0 5.0 1.0 1.0 1.0 5.0


- 209 -

Certified 5.0 5.0 5.0 1.0 1.0 5.0

Plant Protection Schedule (healthy seed crop: hills)

Chemical Insect/disease Doses Time of application

Chlorpyriphos (Dursban)

Cutworms & white grub

15 kg/ha At planting in seed rows.

Metasystox Aphids, jassids, white flies

1.251/ha Drench the ridges when damage is noticed.

Rogor Aphids, jassids, white flies

1.121/ha Every 10 days from 3rd week of May till 1st week of August.

Dithane M-45 Early blight, late blight & Phoma

2 kg/ha Every 10 days from 3rd week of May till 1st week of August.

Metalaxyl (Ridomil)

Late blight 2.5 kg/ha 3rd week of June & 1st week of July combined with insecticide at 8-10 days interval.

Sevin Epilachna beetle, caterpillars & other defoliating insects.

2.5 kg/ha In 2nd week of July on noticing the late blight.

Thiodan Epilachna beetle & other defoliating insects

1.5 l/ha As & when damage on foliage is noticed.

Furadan Cyst nematode 65kg/ha Soil application at the time of planting.

Plant Protection Schedule (healthy seed crop: plains)

Chemical Insect/disease Doses Time of application

Metasystox Aphids, jassids, white flies

1500ml/ha in 1000 lit water

At 10 days interval from 2nd week of November to 3rd week of December in UP, Punjab, Haryana & 1st week of January in MP, Bihar & West Bengal.

Rogor Aphids, jassids, white flies

1250 ml/ha in 1000 lit water

At 10 days interval from 2nd week of November to 3rd week of December in UP, Punjab, Haryana & 1st week of January in MP, Bihar & West Bengal.

Dithane M-45 Early and late blights, phoma blights

2 kg/ha 2nd week of November onward & combined with insecticide at 8-10 days interval.

Metalaxyl (Ridomil)

Late blight 2.5 kg/ha On noticing the late blight

Potato production in India

Year Area (million ha)

Production (million t) Yield (t/ha)

2000-01 1.211 22.142 18.2

2001-02 1.218 24.082 19.7

2002-03 1.337 23.181 17.3

2003-04 1.289 23.060 17.8

2004-05 1.318 23.631 17.9


- 210 -

Quality Spawn Production

K.P.S. Kushwaha Department of Plant Pathology, G.B.P.U.A.&T., Pantnagar-263145 (Uttarakhand)

The term spawn used for the vegetative growth of the mushroom mycelium and the substrate

on which it grows and use to seed the compost. The word spawn is derived from old French verb,

'espandre' meaning to expand. Sinden (1972) defined that veg. growth of mushroom for seeding the

compost is called spawn. Thus it consist of the mushroom mycelium and supporting medium which

provides nutrition to the fungus during its growth. Hence the sawn is equivalent to vegetative seeds of

the mushroom. Mushroom spawn at present, is often referred to in terms of the substrate, e.g. grain

spawn, manure spawn and tobacco stem spawn etc. Now a days only grain spawn is being used for

seeding the compost through out the world. In foreign countries rye grain are preferred over other

grain whereas, in India, wheat, jowar and bajra are commonly used for spawn preparation.

Spawn plays on important role in the mushroom industry because the failure or success of

mushroom cultivation depends upon the availability of the quality spawn. The quality of spawn and yield of

mushroom is mainly governed by the genetic make up of the strain and to some extent, the technology

including and to some extent, the technology including the substrates used in spawn production.

Production of spawn in large quantities needed for commercial use is much more difficult than for

experimental use. Strict hygiene must be observed when spawn has to be produced daily and also great

care need to be taken in the maintenance of strains; failure to do so can have disastrous consequences.

Spawn preparation

Methods of spawn preparation can be divided into three steps.

I. Raising of pure culture:

There are two ways of raising pure culture:

a) Tissue culture raised from a mushroom tissue.

b) Spore culture raised from single or multispores.

a) Tissue culture

A big and healthy fruit body with veil still intact is selected from cropping tray for tissue culture.

Lower portion of the stipe is cut off at the soil level with the help of a pre-sterilized knife and fruit body

is cleaned with a bit of cotton moistened in 50 per cent ethanol to remove the soil particles if any,

adhering to the surface of pileus and stipe and finally dipped in a 0.1 per cent mercuric chloride

solution for 30-60 seconds to avoid any chance of contamination.

A small piece of tissue from the 'unction of cap and stem is taken out with the help of sterilized

inoculating needle' and the same is transferred aseptically in 2% malt extract-agar medium in culture

tubes. The inoculated tubes are incubated at 250C for about 10-15 days till the surface of the medium.

is fully covered with the mycelial growth.

b) Spore culture

(i) Spore collection: A big and healthy fruit body with veil still intact but tightly stretched is selected for


- 211 -

basidiospore collection a sterilized petridish. Lower portion of the stipe is cut off at the soil level with the

help of a pre-sterilized knife and the fructification is washed with distilled water and dipped 0.1.per cent

mercuric chloride solution for 30-60 seconds to avoid any chance of contamination to be introduced with

the spore mass. The fruit bodies is then mounted on a sterilized petridish so that the lower portion of stipe

as well as pileus do not touch the petridish. This is covered by a sterilized beaker for 24-48 hours After a

thick deposition of spore mass, the glass beaker and mushroom alongwith the wire-stand are removed

and sterilized lid is place on the petridish which is then stored in refrigerator until use.

(ii) Single spore culture: In order to isolate single spore, spores are transferred aseptically with the

help of inoculation needle (pre-wetted with sterilized distilled water) into sterilized distilled water and

diluted. One ml of spore suspension containing about 20 spore is transferred and mixed with 2 per

cent melted water agar medium in petri dish. After solidifying the petri dishes are turned up-side down

and single spores are located under microscope and marked with ink. Single spore are picked

individually and transferred on to wheat extract agar medium in test tubes. These tubes are incubated

for 10-15 days at 28C for spore germination.

It must be remembered that all the monosporous cultures of mushrooms of heterothallic nature

(Agaricus bitorquis, Lentinus edodes) are sterile. In secondary homothallic fungus (A. bisporus), 30

per cent of monosporous cultures are sterile.

(iii) Multispore culture: Spore suspension (1%) is mixed with 10 ml liquid malt extract agar medium

in culture tubes and slants are prepared. The slants are incubated at 28C for spore germination for

about two week. The mycelial threads become visible on slant surface after 14-15days.

II. Preparation of master spawn / stock culture

Next step in the spawn preparation is' the preparation of master culture. Pure culture raised

either from tissue or spore is inoculated in a suitable substrate (wheat, jowar, bajra, or rye grains)

which provides food to the mycelium. In principle the quality of spawn is determined by the biological

value of the strain. However, there are some important aspects of spawn making such as proper

understanding of moisture content, pH and sterilization which deserve special: attention for quality

spawn production. Therefore, boiling, soaking, addition of calcium carbonate and calcium sulphate

and sterilization of substrate assumes special significance. For spawn preparation ten kg of wheat

grain or any other substrate is boiled in 15 litres of water for 20 minutes and allowed to remain soaked

in the hot water for another 15 minutes without heating which gives a moisture content of 48-50% of

grains after sterilization. At this moisture content the mycelial growth is fast and number of days taken

by the mycelium to cover the entire substrate is less. Next day 13.5 g calcium sulphate and 3.5g

calcium carbonate are mixed with one kg of boiled grains. The calcium sulphate prevents the sticking

of grains together and calcium carbonate is necessary to adjust the pH (6.6).

The grain is filled into half or one litre milk bottles (250 or 450 g/bottle). Bottles are plugged

with non-absorbent cotton and sterilized at 1.54 kg/cm2 for 2 hours. After autoclaving, bottles are

allowed to cool down slightly and later shaken vigorously to avoid clumping of grains. The sterilized

bottles are surface sterilized by dipping in 2 per cent formalin solution without wetting the cotton plug.


- 212 -

These bottles are inoculated with approximately equal mycelial bits obtained from pure culture.

Inoculated bottles are incubated at 250C. About 7 days after inoculation, bottles are shaken vigorously

so that mycelial threads are well mixed with the grain. About 20 days after inoculation, the bottles are

ready as stock/master culture for further multiplication of the spawn.

III. Preparation of Commercial Spawn

The spawn is also prepared in similar way as described for the preparation of stock culture /

master spawn. One bottle of stock culture is sufficient for inoculation of 25-30 bags of commercial

spawn. Inoculated bags are incubated at 250C. In two weeks spawn bags are ready for use.

Characteristics of good spawn

The spawn should be fast growing in the compost, and should form pin heads quickly after

casing, should be high yielding and should produce good quality mushrooms. There should be a

proper coating of the mycelium around every grain used as a substrate for spawn production. No

loose grain should be seen in the bottles when these are bound together with the mycelium. The

grains left over without mycelial coating will invite mould growth in the compost during spawn running

period. The growth of the mycelium in the spawn bottles should be silky/strandy type. It should not be

cottony type growth because there is likelihood of snioma formation on the casing layer, which

interferes with gaseous exchanges and absorption of water in the casing material resulting in low

yields.

The growth of fresh spawn is more or less white. Brown colouration develops as spawn

grows older. Fresh spawn gives higher yield than the old one. There should not be any slimy growth

in spawn bottle which is an indication of bacterial contamination. There should not be any greenish

or blackish spot in the spawn bottles. Such type of spots indicate that the spawn is contaminated

with moulds.

Transit and storage of spawn

Studies on thermal death point show that the spawn bottles exposed to 40C for 48h result in

killing of the mycelium. However, the spawn exposed to 35C remains viable for 14 days. Care must

be taken during transit that spawn bottles are not exposed to a temperature higher than 350C. To

avoid such risk spawn bottles can be packed in thermocol boxes containing ice cubes or can be

transported during when it is cool.

Storage of spawn should be avoided as far as possible. However, the spawn can be stored

between 3-5C for one to six months in case it is not used due to certain unavoidable circumstances.


- 213 -

Bio-intensive IPM for Crop Disease Management on Small Farms

J. Kumar Department of Plant Pathology, G.B.P.U.A.&T., Pantnagar-263145 (Uttarakhand)

Bio-intensive farming system is based on the agro-ecological principles of sustainable organic

agriculture system and participatory rural development. These principles include the scientific crop

rotation, mixed farming system with specialized crop and/or livestock/agroforestry enterprise(s),

optimization of organic recycling, participatory and sustainable management of natural resources (land,

forest, water, plant/animal biodiversity), participatory research and extension, and higher degree of

economic self-reliance of farm households against external techno-economic shocks.

Pest management on such farming systems is an ecological matter. The most effective

suppression of pests, diseases and weeds (pests) is achieved when producers integrate a variety of

tactics that prevent, avoid or mitigate crop losses, with limited need for the use of suppressive

measures, including pesticides. The term Integrated Pest Management (IPM) is used to define this

approach, which is based on an understanding of the ecology of the pest organism and the relative

contributions that cultural, biological and chemical approaches make to pest suppression. The term

Biointensive IPM, defines the more dynamic and ecologically-informed approach to IPM that considers

the farm as part of an agroecosystem, with particular characteristics that need to be understood and

managed in order to minimize pest damage. This approach is information-intensive, and it relies upon

diagnosis and observation, combined with a commitment to longer-term, ecologically-based solutions

to pest problems.

Biointensive IPM incorporates ecological and economic factors into agricultural system design

and decision making, and addresses public concerns about environmental quality and food safety. The

benefits of implementing biointensive IPM can include reduced chemical input costs, reduced on-farm

and off-farm environmental impacts, and more effective and sustainable pest management. An

ecology-based IPM has the potential of decreasing inputs of fuel, machinery, and synthetic

chemicals—all of which are energy

intensive and increasingly costly in terms of financial and environmental impact. Such

reductions will benefit the grower and society. The primary goal of biointensive IPM is to provide

guidelines and options for the effective management of pests and beneficial organisms in an ecological

context. The flexibility and environmental compatibility of a biointensive IPM strategy make it useful in

all types of cropping systems.

Bio-intensive IPM make use of proactive options, such as crop rotations and creation of habitat

for beneficial organisms, permanently lower the carrying capacity of the farm for the pest. The carrying

capacity is determined by factors like food, shelter, natural enemies complex, and weather, which affect

the reproduction and survival of a species. Cultural controls are generally considered to be proactive

strategies and largely involve maintaining healthy, biologically active soils (increasing belowground

diversity) and creating habitat for beneficial organisms (increasing aboveground diversity).


- 214 -

Maintaining and increasing biological diversity of the farm system is a primary strategy of

cultural control. Decreased biodiversity tends to result in agroecosystems that are unstable and prone

to recurrent pest outbreaks and many other problems . Systems high in biodiversity tend to be more

“dynamically stable”—that is, the variety of organisms provide more checks and balances on each

other, which helps prevent one species (i.e.,pest species) from overwhelming the system. There are

many ways to manage and increase biodiversity on a farm, both above ground and in the soil. In fact,

diversity above ground influences diversity below ground. Research has shown that up to half of a

plant’s photosynthetic production (carbohydrates) is sent to the roots, and half of that (along with

various amino acids and other plant products) leaks out the roots into the surrounding soil, providing a

food source for microorganisms. These root exudates vary from plant species to plant species and this

variation influences the type of organisms associated with the root exudates. Factors influencing the

health and biodiversity of soils include the amount of soil organic matter; soil pH; nutrient balance;

moisture; and parent material of the soil. Healthy soils with a diverse community of organisms support

plant health and nutrition better than soils deficient in organic matter and low in species diversity.

Research has shown that excess nutrients (e.g., too much nitrogen) as well as relative nutrient balance

ual

amounts of both) in soils affect insect pest response to plants. Imbalances in the soil can make a plant

more attractive to insect pests , less able to recover from pest damage, or more susceptible to

secondary infections by plant pathogens. Soils rich in organic matter tend to suppress plant pathogens.

In addition, it is estimated that 75% of all insect pests spend part of their life cycle in the soil, and many

of their natural enemies occur there as well. For example, larvae of one species of blister beetle

consume about 43 grasshopper eggs before maturing. Both are found in the soil. (Unfortunately,

although blister beetle larvae can help reduce grasshopper populations, the adult beetles can be a

serious pest for many vegetable growers.) Overall, a healthy soil with a diversity of beneficial

organisms and high organic matter content helps maintain pest populations below their economic

thresholds. Such an approach is best suited to small farms such as in uttarakhnad hills where farmers

largely make use of on-farm available resources for sustenance of agriculture production.

Small-scale farmers are the bedrock of Himalayan economic development. The tremendous

pressure on farmers to make a living from the land and yet maintain a healthy environment has

gathered momentum all around. This translates into market demand for constant and consistent

supplies of higher quality and safer food at even lower prices, all with in the context of farmers’

awareness of the environment and its sustainability. Often the response is high levels of chemical

inputs, reduced rotations and extensive monocultures. The search for greater and ever-cheaper

production with increased intensification reduces the biodiversity of the system itself. Thus impact of

diseases increases over the time. Control of these diseases has traditionally depended upon soil

quality improvement strategies and has greater relevance at the end of small farmers.


- 215 -

Small farmers have poor infrastructure and market access, it is economic for small farmers to

use high levels of external inputs. The challenge is to develop low-external –input technologies that

boost labor and land productivity.

Rainfed farming and intensive cultivation on small and fragmented lands is characteristic of

agriculture in Uttaranchal hills. On an average land holding of less than a hectare, production per kg

seed sown is low and, which is on the decline. Such a situation has arisen due to intensive cropping

and declining fertility of soil; increasing impact of plant diseases; not being able to follow crop rotation,

deep ploughing and leaving the field fallow even for a short period; greater reliance on the use of

chemicals; vagaries of weather; etc. Yet pressure of producing more out of a meager land is ever

mounting. Less land per person requires more high yielding agriculture. To increase yield from

existing land requires good crop protection against losses before and after harvesting, which, must be

achieved within the framework of Integrated Pest Management (IPM). Increased agricultural

productivity and increased damage due to diseases and insect pests have intimate relationship. IPM,

nevertheless, offers an important principle on which sustainable crop protection can be based. It offers

the best combination of cultural, biological, and chemical measures that provides the most cost

effective, environmentally sound and socially acceptable method of managing diseases, insects, and

pests.

Farmers in the region, over the time, have been fighting to save their crops from the onslaught

of diseases and pests. Infact, their agricultural practices are making their crops more vulnerable to the

attack of biotic and abiotic agents. The amount of profit on small farms is less, thus farmers do not

have capacity to bear any amount of losses. The challenge is to apply research to issues that lead to

insecurity amongst small and marginal farmers as regards crop management and protection.

Under crop diversification plan in the state, off-season vegetable cultivation is poised to play a

unique role in the hill farming system in Uttaranchal state. Being low volume and high value crops they

are rated to be potential cash earners. Unfortunately, however, all these cash crops suffer recurrent

chronic losses due to a variety of diseases and pests. The per hectare agrochemical usage in the

vegetable crops is very high as compared to cereal crops with a simultaneous increase in the pesticide

consumption. This trend where on one hand threatens the highly fragile Himalayan ecosystem, on the

other it does not fit with in the frame work of organic farming, which is the state policy. Seed and soil

borne pathogens cause much of the recurrent losses (nearly 80%) in vegetables each season in the

region. The cost of soil borne pathogens to society and the environment far exceeds the direct costs

to growers and consumers. The use of chemical pesticides to control soil borne pathogens has

caused significant changes in air and water quality, altered natural ecosystems resulting in direct and

indirect effects on wild life, and caused human health problems. Long-term chemical applications may

permanently alter the microbial community structure to an extent that sustainable agriculture may be

impossible. The opportunity, therefore, exists to address the issues relating to IPM across ecosystems

through a Common Minimum Programme, which can alleviate considerable losses to vegetables

that result only from soil borne problems. Other location-specific problems could be addressed


- 216 -

through supplementary intervention(s). The key components of CMP are, a) plastic mulching (soil

solarization) of nursery beds and fields, b) use of bioagents for seed treatment, seedling treatment, soil

treatment and foliar application, c) Bio-composting including vermi composting and d) use of value-

added vermicompost and FYM. Other location-specific problems could be addressed through

supplementary intervention(s).

At small farms, it is appropriate to develop disease control strategies that have an ecological

base such that the agroecosystem should encourage the growth and diversity of soil inhabiting and

epiphytic microorganisms that can exert beneficial and pathogen antagonistic influence. Biological

control of plant pathogens, broadly refers to the use of one living organism to curtail the growth and

proliferation of another, undesirable one, is promising alternative to the use of chemicals. In nature,

some microorganisms affect or suppress growth of pathogenic microorganisms. These beneficial

organisms are collectively called as ‘biological control agents or biocontrol agents’. Biological

protection against infection is accomplished by destroying the existing pathogen inocula, by preventing

the formation of additional inocula, or by weakening and displacing the existing virulent pathogen

population. This is achieved through protection of plant material and roots with biological seed

treatments, or suppression of pathogens by the introduction of plant associated antagonists into the

rhizosphere. Microbial agents may be stimulated in the plant rhizosphere by the addition of

suppressive composts such as vemricompost. Vermicomposting, is a natural process by which

earthworms and micro-organisms convert organic waste into humus that is used as a nutrient-rich soil

conditioner. Earthworms play a key role in soil biology. They harness beneficial soil microflora, destroy

soil pathogens, convert organic wastes into valuable products such as biofertilizers, biopesticides,

vitamines, enzymes, growth hormones, and proteineous worm biomass. Use of vermicompost has

been found to reduce the menace of white grub, which more often propagates and spreads through

undecomposed farm yard manure. Soil solarization is a ‘low-investment high value’ technology and

leads to disease and weed control, better plant stand, health and vigour, and early readiness of

seedlings for planting. Plants emerged out of solarized beds are healthier, grow faster and the beds

have lesser weed population. Value addition of vermicomposts through the incorporation of bioagents

ensures goodness of vermicompost and adds value of the bioagents.

Root rot complex (caused by Fusarium solani. f.sp. pisi and Rhizoctonia solani) and collar rot

(caused by R. solani) are the serious most threats to most vegetables in the nurseries as well as in the

field in most farming situations. Inadequate rotations aggravate crop losses. Use of synthetic

chemicals for management of diseases is largely uneconomical and does not fit within the framework

of ‘organic farming’, the state policy. Through adoption of Common Minimum Programme losses

through seed and soil borne diseases could be severely minimized. The ultimate aim is to raise

healthy plant, which can resist/ withstand attacks of biotic and abiotic agents and host plant growth

promoting rhizobacteria and antagonists. This is achieved through maintaining microbial diversity in

the soil, creating conditions suitable for their growth and development through providing habitats for

their growth. Common minimum programme tends to fulfill these objectives. Through the adoption of


- 217 -

CMP farmers can reduce cost of production, minimize losses due to pests and diseases, increase

benefit-cost ratio and raise value-added crop. Small farmers are experimenters and inventors.

Improving farmers’ ability to manage disease requires knowledge, capacity for innovation and on-farm

decision-making. Through farmers’ field schools farmers have been oriented to learn necessity of

adoption of CMP and the role it can play in bringing sustainability into their agriculture.

Through adoption of Common Minimum Programme losses through seed and soil borne

diseases as well as insects could be severely minimized. The ultimate aim is to raise healthy plant,

which can resist/ withstand attacks of biotic and abiotic agents. This is achieved through maintaining

microbial diversity in the soil, creating conditions suitable for their growth and development through

providing habitats for their growth. Common minimum programme tends to fulfill these objectives.

Through the adoption of CMP farmers can reduce cost of production, minimize losses due to pests

and diseases, increase benefit-cost ratio and raise value-added crop. During initial few years, CMP is

being adopted by over 3000 farmers from 55 villages in districts Tehri, Pauri, Almora, Champawat,

Nainital and Udham Singh Nagar. Depending on the extent of damage to the soil ecology through

indiscriminate use of chemicals, varying degree of success has been achieved. However, with

continuous adoption of CMP success rate can be quite high. Thus, the ‘zero’ or ‘low cost technology’

while on one hand offers a solution to the recurrent diseases and pest problems, on the other falls with

in the framework of organic farming, which is the state policy. To the predominantly agrarian economy

in the state, CMP can prove handy to the small farmers in the years to come. There, however,

remains the necessity to enforce implementation of CMP through extension functionaries in the state

for its widespread adoption and implementation. On similar lines, such plans that apply ecological

principles in pest management need to be developed for other crops.

REFERENCES

1. Altieri, Miguel A. 1994. Biodiversity and Pest Management in Agroecosystems. The Haworth Press, Binghamton, NY. 185 p.

2. Marschner, H. 1998. Soil-Root Interface: Biological and Biochemical Processes. p. 191-232. In: Soil Chemistry and Ecosystem Health. P.M. Huang (ed.). Soil Science Society of America, Inc., Madison, WI.

3. Phelan, L. 1997. Soil-management history and the role of plant mineral balance as a determinant of maize susceptibility to the European Corn Borer. Biological Agriculture and Horticulture. Vol. 15. (1-4). p. 25-34.

4. Daane, K.M. et al. 1995. Excess nitrogen raises nectarine susceptibility to disease and insects.

5. California Agriculture. July-August. p. 13-18.

6. Schneider, R.W. 1982. Suppressive Soils and Plant Disease. The American Phytopathological Society. St. Paul, MN. 88 p.

7. Metcalf, Robert L. 1993. Destructive and Useful Insects: Their Habits and Control, 5th ed. McGraw-Hill, NewYork, NY.

8. Zhu, Y., H. et al. 2000. Genetic diversity and desease control in rice. Nature. 17 August. p. 718-722.

9. Leslie, Anne R. and Gerritt Cuperus. 1993. Successful Implementation of Integrated Pest Management for Agricultural Crops. CRC Press,Boca Raton, FL. 193 p.

VALEDICTORY ADDRESS by

Prof. A.P. Sharma

Vice-Chancellor


on

April 17, 2008

It is a pleasure having to deliver the

valedictory address on the successful completion

of the CAS training on “Seed Health

Management for Better Productivity” (March 28

to April 17, 2008). I am sure that you all have

enjoyed the scientific interaction during your stay

at Pantnagar as well as exposure trip to NBPGR,

New Delhi (April 03-05, 2008).

In my view, the greatest threat to the

well-being of mankind is over population. Human

population is projected to grow at ca 80 millions

per annum, increasing by 35% to 7.7 billion by

2020, then by about 75% before leveling off at

about 10 billion. This increased population

density, coupled with changes in the dietary

habits in developing countries towards high

quality food and the increasing use of grains for

livestock feed, is projected to cause the demand

for grain production to more than double.

However land suitable for agriculture production

is limited, and most of the soil with high

productivity potential are already under

cultivation. In addition, the availability of water is

restricted, and in some regions land resources

are depleted and the cultivated area is shrinking.

Given these limitations, sustainable production at

elevated levels is urgently needed. The

availability and conservation of fertile soils and

the development of high-yielding varieties are

major challenges to agriculture production.

Safeguarding crop productivity by protecting

crops from damage by weeds, pests and

pathogens is also a major requisite for providing

food and feed in sufficient quantity and quality.

Improved crop management systems

based upon genetically improved cultivars,

enhanced soil fertility via chemical fertilization,

pest control via synthetic pesticides, and

irrigation were the hallmarks of the Green

Revolution. The combined effect of these factors

allowed world food production to double in the

past 35 years. The three annual crops viz., rice,

maize and wheat, occupy almost 40% of the

global crop land and are the primary sources for

human nutrition world wide. As yield of these

and some cash crops positively respond to high

production levels and/or cultivation may be

largely mechanized, in the last decades, world-

wide crop production has focused on a limited

number of plant species. Diverse ecosystems

have been replaced in many regions by simple

agro-ecosystems which are more vulnerable to

pest attack. In order to safe guard productivity to

the level necessary to meet the demand, these

crops have to be protected from pests.

The yield of cultivated plants is

threatened by competition and destruction from

pests, especially when grown in large scale

monocultures or with heavy fertilizer applications.

However, problems created by seed-borne

disease are highly ignored and control measures

unknown or inadequate. The consequence is

poor seed quality, dissemination and buildup of

seed-borne diseases and yields far below the

i

potential. An improvement in quality and health

of seed for sowing constitutes a large

unexploited potential for increased food

production of unknown dimensions.

As I reminded you earlier in my inaugural

address, “Seed Health Management is one of the

pathways to achieving the UN Millennium

Development Goal relating to the elimination of

hunger and poverty” as has been believed by Prof.

Swaminathan. There is, thus, every need to

address the use of quality seed for boosting

production and productivity. Undoubtedly, the

science of Plant Pathology and seed pathology in

particular, has an important role in the future

success of programs and policies designed to

increase and sustain food production.

Unawareness of quality seed particularly the

healthy disease free seed is one of the major

concerns of today. Infected seeds not only

disseminate the pathogens in previously diseases

free areas but also lead to reduced germination,

seedling vigor and ultimately the yield of the crop. It

is estimated that 30% disease are seed borne and

can be managed through disease free seed. Seed

Health testing is needed to be understood, in the

light of general evolution of seed sector in modern

agriculture. Seed health testing may be used as a

tool to establish predictive relationship between

seed borne inoculum and disease incidence,

suggestive measures for effective seed treatment

for better productivity.

Seed replacement rate (SRR) in different

crops is still very low in the country. For the

major crops such as wheat and rice it is

approximately 10.0 % and 20.0% respectively,

(report form NSP). For other crops also situation

is not so encouraging. In crops where hybrids

are available, SRR should be 100%, which

unfortunately is not being maintained. Thus,

there is urgent need to increase the quality of

seed produced so that SRR may be increased to

a satisfactory level.

The importance of seed may be realized

by the fact that the ICAR has launched “National

Seed Project” and recently a “Mega Seed

Project”, nationwide, with different disciplines for

quality seed production in India. Still with the

efforts and improvements in the Seed

Programme, the area coverage under quality

seed is only about 12 % while the rest is under

farmers own seed. Therefore, it of paramount

importance to improve the status of healthy

seed production and its use through educating

farmers, replacement of the seed frequency,

demonstration of seed production and

management practices at the farmers level.

In my opinion, the only farm with a future

will be farms that are sustainable, economically

viable, ecologically sound and socially

responsible. Sustainable crop production,

therefore, holds big promise for the future

provided quality seed is made available to the

farmers.

I am delighted to know that all above

points have been appropriately addressed in this

particular training course, which I am sure was

very well designed and appropriately conducted.

It is hoped that you would use the

knowledge gained here in teaching, research

and extension activities at your respective

institution/university. You are now in a way

alumini of this university and I am sure that you

will maintain this linkage in a dynamic manner for

our mutual benefit in the pursuance of science

of Plant Pathology, especially in the area of seed

health management.

I wish you a safe and comfortable return

journey back home and fruitful professional

career ahead.

“Jai Hind”

ii

ANNEXURE-I

CENTRE OF ADVANCED STUDIES IN PLANT PATHOLOGY

College of Agriculture, Pantnagar-263 145 (Uttarakhand)

Following committees have been constituted for smooth conduct of the training

programme on “Seed Health Management for Better Productivity” scheduled on

March 28 to April 17, 2008.

1. Overall Supervision

Dr. J. Kumar, Director CASPP

Dr. S. C. Saxena

Dr. K.P. Singh

Dr. R.P. Singh

Dr. A.P. Sinha

Dr. H.S. Tripathi

2. Course Faculty

Dr. J. Kumar – Course Director

Dr. S.C. Saxena, Course Coordinator

Dr. H.S. Tripathi

Dr. R. P. Awasthi

Dr. (Mrs.) K. Vishunavat

Dr. V.S. Pundhir

3. Inaugural and Closing Function

Committee

Dr. H.S. Tripathi– Chairman

Dr. A.K. Tewari

Mr. Narender Singh

Mr. S.P. Yadav

Mr. Mani Ram

4. Inaugural Session & Intersession Tea

Committee

Dr. Pradeep Kumar – Chairman

Dr. K.K. Mishra

Dr. Ajeet Kumar

Mr. S. P. Yadav

Mr. Jagannath

5. Budget Committee

Dr. R. P. Awasthi – Chairman

Dr. Yogendra Singh

Mr. K. S. Bhatnagar (Acco. Officer)

Mr. A. B. Joshi

Mr. Praveen Kumar

Mr. Het Ram

6. Transport and Reception Committee

Dr. R. R. Dwivedi – Chairman

Dr. K.P.S. Kushwaha

Mr. Prakash Joshi

Mr. Bhuwan Chand Sharma

Mr. Bhupesh Kabadwal

7. Boarding & Loading Committee

Dr. V.S. Pundhir – Chairman

Dr. R.K. Bansal

Mr. S. P. Yadav

Mr. Dev Kumar Chaube

8. Registration Committee

Dr. (Mrs) K. Vishunavat – Chairperson

Dr. P. Kumar

Dr. (Mrs.) Kanak Srivastava

Dr. (Mrs.) Renu Singh

i

9. Session Arrangement Committee

Dr. S.C. Saxena – Chairman

Dr. P. Kumar

Dr. Y. Singh

Mr. Prakash Joshi

Mr. Vikram Prasad

Mr. Leela Ram

10. Editing, Publication, Printing, Certificates, etc. Committee

Dr. (Mrs.) K. Vishunavat - Chairperson

Dr. A.K. Tewari

Dr. Ajeet Kumar

Mr. Praveen Kumar

Mr. P.C. Khulbe

11. Field / Excursion Trip Committee

Dr. R. R. Dwivedi – Chairman

Dr. R.K. Sahu

Dr. M.K. Sharma

Mr. K. S. Bisht

Mr. R. B. Sachan

12. Laboratories & General Maintenance

Committee

Dr. K.S. Dubey– Chairman

Dr. Akhilesh Singh

Mr. A. B. Joshi

Mr. Bhupesh Chandra Kabdwal

Mr. Rajendra Pandey

13. Committee for Typing, Correspondence

work

Dr. S. N. Vishwakarma - Chairman

Dr. Akhilesh Singh

Smt. Meena Singh

Mr. Vishnu Rai

Mr. Mehboob

14. Audiovisual Aid & Publicity Committee

Dr. A.P. Sinha-Chairman

Dr. Akhilesh Singh

Dr. A.K. Tewari

Mr. R.C. Singh

Mr. Ramakant Singh

Mr. Bupesh Kabdwal

ii

ANNEXURE-II

LIST OF PARTICIPANTS

Sl. No.

Name and Address Phone/E-mail

1. Dr. Lal Bahadur Yadav

Asstt. Professor, Plant Pathology

V.C.S.G. College of Hort., Bharsar

Pauri Garhwal-246 123 (UK)

(O): 01348-226071 (R): 01348-226003, 226018 E-mail: [email protected]

2. Dr. Sanjeev Sharma

Asstt. Prof./SMS (Plant Protection)

Krishi Vigyan Kendra,

Bharsar Via Chipalghat,

Pauri Garhwal- 246 123 (UK)

(O): 01348-226076 (R): 01348-226058 E-mail: [email protected]

3. Dr. Satish Chand

JRO, Department of Horticulture

College of Agriculture

G.B.P.U.A.&T., Pantnagar-263 145 (UK)

(O): 05944-233556 (R): 05944-233111 E-mail: [email protected] [email protected]

4. Dr. (Mrs.) Nirmala Bhatt

SMS/Asstt. Professor (Plant Protection)

Krishi Vigyan Kendra, Gaina-Aincholi,

Pithoragarh- 262 530 (UK)

(O): 05964-252175 (R): 9412044788 E-mail: [email protected]

5. Dr. (Mrs.) Swati

JRO, Wheat Breeding

Department of Genetics & Pl. Breeding

GBPUA&T, Pantnagar- 263 145 (UK)

(R): 05944-233297

6. Dr. Anil Kumar

JRO, Genetics & Plant Breeding

GBPUAT, Pantnagar- 263 145 (UK)


7. Dr. Mukesh Vyas

Asstt. Professor

Deptt. of Plant Breeding & Genetics

Rajasthan College of Agriculture,

M.P.U.A.&T., Udaipur- 313 001 (Raj.)


8. Dr. R.R. Ahir

Asstt. Prof. Deptt. of Plant Pathology

SKN College of Agriculture,

Jobner, Jaipur- 303 329 (Rajasthan)

(Mb.) 09414516629

i

9. Dr. Pradip Kumar Borah

Sr. Scientist, STR, Director of Research

Seed Technology Research, NSP Crops

Assam Agricultural University,

Jorhat- 785 013 (Assam)

(O): 0376-2340015 (R): 0376-2340636 (Mb.) 9954729041 E-mail: [email protected]

10. Dr. Anil Kumar Sachan

Asstt. Prof./Asstt. Director, Seed & Farms

C.S.A.U.A&T., Kanpur- 208 002 (UP)

(O): 0512-2533925 (R): 0512-2600392 (Mb.) 09450124265 E-mail: [email protected]

11. Dr. Ramesh Singh Yadav

Asstt. Prof. Deptt. of Plant Pathology

S.V. Bhai Patel Univ. of Agri.&Tech.,

Meerut- 250 110 (UP)

(O): 09412833798 (R): 0121-6453467 E-mail: [email protected]

12. Dr. (Mrs.) Savita Ekka

Jr. Scientist cum Asstt. Prof., Plant Path.

Birsa Agricultural University,

Ranchi- 834 006 (Jharkhand)


13. Prof. Bhatu Shripat Patil

Asstt. Prof. of Plant Pathology

MPKV, College of Agriculture

Dhule- 424 004 (Maharashtra)

(O): 02562-230368 (R): 02562-275017 (Mb.): 9422961793

14. Mr. Sanjay Baburao Gawade

Asstt. Seed Research Officer (Asstt. Prof.)

Department of Agricultural Botany

MPKV, Rahuri-413 722

Distt. Ahmednagar (Maharashtra)

(O): 02426-243330 (Mb.): 9420639394

15. Dr. M.P. Basavarajappa

SMS (Plant Pathology)

Krishi Vigyan Kendra

Regional Agricultural Research Station

Raichur- 584 101 (Karnataka)

(O): 08532-220196 (Mb.) 09341459469 E-mail: [email protected]

16. Dr. A.G. Najar

Sr. Scientist-cum-Assoc. Prof. (Pl. Path)

Division of Plant Pathology,

SKUAST-Kashmir, Shalimar

Srinagar- 191 121 (J&K)

(O): 0194-2461258-3600 (R): 9419720384 (Mb.) +91 951951-23346 E-mail: [email protected]

17. Mr. Tanveer Ahmad Wani

Asstt. Professor/Jr. Scientist

Division of Plant Pathology

SKUAST-K Srinagar- 191 121 (J&K)

(O): 9419033782 (R): 01952-235290 E-mail: [email protected]

ii

18. Dr. C. Anil Kumar

Scientist-B

Department of Genetic Resources

Tropical Botanic Garden & Res. Institute

Thiruvananthapuram- 695 562 (Kerala)


19. Dr. Dinesh Singh Tomar

Assistant Professor, Deptt. of Pl. Path.

JNKVV, College of Agriculture,

Tikamgarh- 472 001 (MP)

(O): 07683-245136 (Mb.) 09826485150 E-mail: [email protected] [email protected]

20. Dr. Mayani Naran Ghusabhai

Asstt. Prof. Department of Plant Path.

Junagadh Agril. University,

College of Agriculture

Junagadh- 362 001 (Gujarat)

(O): 0285-2672080-90 Ext. 355, 403 (Mb.) 9428438473 E-mail: [email protected]

21. Dr. Deepak Singh

SMS (Plant Protection)

Krishi Vigyan Kendra,

Sitamarhi- 843 320 (Bihar)

(O): 06228-286321/225598 (R): 9430867197 E-mail: [email protected] [email protected]

S U M M A R Y

Sl. No. State No. of participants

1. Assam 01

2. Bihar 01

3. Gujarat 01

4. Jharkhand 01

5. Jammu & Kashmir 02

6. Kerala 01

7. Karnataka 01

8. Madhya Pradesh 01

9. Maharashtra 02

10. Rajasthan 02

11. Uttarakhand 06

12. Uttar Pradesh 02

Total Participants 21

iii

ANNEXURE-III

TRAINING

ON

SEED HEALTH MANAGEMENT FOR BETTER PRODUCTIVITY

(March 28 to April 17, 2008)

Venue Committee Room, Department of Plant Pathology

Sponsored by Centre of Advance Studies in Plant Pathology (ICAR, New Delhi)

Faculty Dr. J. Kumar, Director CAS Plant Pathology

Dr. S.C. Saxena, Course Coordinator

Dr. H.S. Tripathi, Professor

Dr. R.P. Awasthi, Professor

Dr. (Mrs.) K. Vishunavat, Professor

Dr. V.S. Pundhir, Professor

GUEST SPEAKERS/CONTRIBUTORS Dr. R.C. Sharma Professor, Seed Technology Centre, Punjab Agriculture

University, Ludhiana

Dr. A.K. Gaur Janakpuri, New Delhi- 110 058

Dr. Y.P. Singh Scientist, Forest Pathology Division, Forest Research Institute,

Dehradun-248 006

Dr. R.D. Kapoor Regulatory Lead, Monsento India Ltd., 6-B Jorbagh Lane Ground

Floor- New Delhi- 110 063

Dr. O.K. Sinha Principal Scientist & Coordinator (AICRP Sugarcane), Indian

Institute of Sugarcane Research, Lucknow (UP)

Dr. R.L. Agrawal A-731 Indira Nagar, Lucknow- 226 016

Dr. U.S. Singh South Asia Coordinator, IRRI, Delhi

Dr. S.K. Sharma Director, NBPGR, New Delhi

Dr. R.K. Khetrapal Head, Plant Quarantine, NBPGR, New Delhi

Dr. Baleshwar Singh Principal Scientist, Plant Pathology, NBPGR, New Delhi

Dr. Rajan Principal Scientist, Nematology, NBPGR, New Delhi

Dr. V.C. Chalam Senior Scientist, Plant Pathology, NBPGR, New Delhi

Dr. D.B. Parakh Principal Scientist, Plant Pathology, NBPGR, New Delhi

Dr. P.C. Agarwal Principal Scientist, Plant Pathology, NBPGR, New Delhi

Dr. (Mrs.) Usha Dev Principal Scientist, Plant Pathology, NBPGR, New Delhi

Dr. (Mrs. Kavita Gupta Senior Scientist, Ag. Entomology, NBPGR, New Delhi

Dr. B. Lal Principal Scientist, Ag. Entomology, NBPGR, New Delhi

Dr. (Mrs.) Shashi Bhalla Principal Scientist, Ag. Entomology, NBPGR, New Delhi

Dr. (Mrs.) M.L. Kapoor Principal Scientist, Ag. Entomology, NBPGR, New Delhi

i

LOCAL SPEAKERS Dr. J.P. Tiwari Dean, College of Agriculture

Dr. V.P.S. Arora Dean, CABM

Dr. J. Kumar Professor and Head-cum-Director CAS Plant Pathology

Dr. K.P. Singh Director Extension Education

Dr. S.C. Saxena Professor (Guest Faculty), Plant Pathology

Dr. A.P. Sinha Professor, Plant Pathology

Dr. H.S. Tripathi Professor, Plant Pathology

Dr. S.N. Vishwakarma Professor, Plant Pathology

Dr. R.P. Awasthi Professor, Plant Pathology

Dr. (Mrs.) K. Vishunavat Professor, Plant Pathology

Dr. V.S. Pundhir Professor, Plant Pathology

Dr. R.R. Dwivedi Professor, Plant Pathology

Dr. P. Kumar Professor, Plant Pathology

Dr. R.K. Sahu Professor, Plant Pathology

Dr. K.P.S. Kushwaha SRO, Plant Pathology

Dr. S.K. Saini Professor & Head, Agronomy

Dr. P.R. Rajput Professor, Agronomy

R.S. Verma Professor, Agronomy

Dr. Shri Ram Yadav Professor, Entomology

Dr. S.N. Tewari Professor, Entomology

Dr. Ruchira Tewari Asstt. Prof., Entomology

Dr. B. Mishra Professor, Soil Science

Dr. Balwinder Singh Assoc. Prof., Vet. Anotomy

Dr. D.K. Singh Assoc. Prof., Vegetable Science

Dr. H.S. Chawla Professor, Genetics and Plant Breeding

Dr. S.C. Mani Professor, Genetics and Plant Breeding

Dr. Salil Tewari Professor, Genetics and Plant Breeding

Dr. M.K. Nautiyal Assoc. Prof., Genetics and Plant Breeding

Dr. B.B. Singh Visiting Professor, Genetics and Plant Breeding

Dr. Deepak Pandey Jt. Chief Seed Production Officer, TDC

Shri H.K. Singh General Manager, TDC

Dr. N.S. Murty Professor, Agrometeorology

Dr. B. Kumar Professor & Head, Agriculture Communication

Dr. Anil Kumar Professor and Head, MBGE

Dr. S. Marla Assoc. Professor, MBGE

Dr. Arundhati Kausik Assistant Librarian

ii

ANNEXURE-IV

CENTRE OF ADVANCED STUDIES IN PLANT PATHOLOGY G.B. Pant University of Agri. & Tech., Pantnagar-263 145

Course Schedule (March 28 to April 17, 2008)

“SEED HEALTH MANAGEMENT FOR BETTER PRODUCTIVITY”

Venue : PG Lab- Department of Plant Pathology

Day & Date Time Topic ( Lecture/ Lab) Speaker/Contact

Friday March 28

09:30-10:30 hrs Registration and Introduction with Plant Pathology

Faculty & Visit to Plant Pathology Labs

Registration

committee, PG Lab

10:30-11:30 hrs Department of Plant Pathology and CAS activities at

Pantnagar

Dr. J. Kumar Director CAS Pl. Pathology

11:30-11:45 hrs Tea Break

11:45-13:00 hrs Visit to Department

13:00-14:30 hrs Lunch

14:30:17:00 hrs Visit to CRC, LRC, HRC, VRC, University Campus Dr. R.K. Sahu

Saturday March 29

09:30-11:00 hrs Inaugural Function

Venue: Conference Hall, Agriculture College


11:30-11:45 hrs College of Agriculture at a glance Dr. J.P. Tewari, Dean

13:00-14:30 hrs Lunch

14:30-17:00 hrs Visit-CD-ROM search (University Library) Dr. Arundhati Kaushik

Sunday March 30

09:30-12:30 hrs Quality spawn Production and visit to different units

of MRTC

Dr. K.P.S. Kushwaha

Monday March 31

09:30-10:30 hrs Priorities in Seed Pathology and Seed health

Testing Research

Dr. K. Vishunavat

10:30-11:30 hrs Seeds: The tale of biotechnology Anil Kumar, CBSH


11:45-13:00 hrs Quality seed production and soil health Dr. B. Mishra

13:00-14:30 hrs Lunch

14:30-15:30 hrs Seeds : Intellectual Property Dr. H.S. Chawla


15:45-17:00 hrs TA business Dr. R.P. Awasthi

Tuesday April 01

09:30-10:30 hrs Quality seed for better sugarcane productivity Dr. S.K. Saini

10:30-11:30 hrs Integrated disease management for vegetable seed

production

Dr. S.N. Vishwakarma


11:45-13:00 hrs Development of Immunochemical and PCR

Methods for Qualitative Detection of seed borne

pathogens

Dr. S. Marla, CBSH

i

13:00-14:30 hrs Lunch

14:30-15:30 hrs Seed Health Testing and seed quality management

in pulses

Dr. H.S. Tripathi


15:45-17:00 hrs Management of Plant Propagating material for

quality control in forest crops

Dr. P.R. Rajput

Wednesday April 02

09:30-10:30 hrs Scientific stress management Dr. Shri Ram

10:30-11:30 hrs New approaches to pest risk analysis for quarantine

pests

Dr. Ruchira Tewari


11:45-13:00 hrs Seed health and banded leaf & sheath blight of

maize

Dr. S.C. Saxean

13:00-14:30 hrs Lunch

14:30-17:00 hrs Common Laboratory Seed Health Testing Methods

for Detecting Fungi

Dr. K. Vishunavat

20:30 hrs. Departure to Plant Quarantine Division, NBPGR,

New Delhi

Drs. R.R. Dwivedi & R.P. Awasthi

Thursday April 03

14:00-14:45 hrs Transboundary movement of seed transmitted

pests: A global perspective

RK Khetarpal, Kavita Gupta, Rajan

14:50-15:30 hrs Detection of seed transmitted fungi in quarantine PC Agarwal, Usha Dev

15:35-16:25 hrs Detection of seed transmitted bacteria in quarantine Baleshwar Singh, PC Agarwal

16:30-17:00 hrs Salvaging of seed transmitted fungi and bacteria in

quarantine

Usha Dev, Baleshwar Singh

Friday

April 04

09:30-10:15 hrs Seed certification and policy issues in plant

protection

RK Khetarpal, Kavita Gupta and VC Chalam

10:20-11:00 hrs Detection and management of seed borne

nematodes in quarantine

Rajan, Arjun Lal,

Naresh Kumar

11:00-13:00 hrs Visit to National Gene Bank

13:00-14:15 hrs Lunch Break

14:15-15:00 hrs Detection and management of seed transmitted

viruses in quarantine

VC Chalam, DB Parakh, RK Khetarpal

15:00-16:00 hrs Post entry quarantine facilities and requirements DB Parakh, VC Chalam, RK Khetarpal

16:00-17:30 hrs Detection of GMOs VC Chalam, Digvender Pal, RK Khetarpal

Saturday April 05

09:30-10:15 hrs Detection of insects and mites infesting seeds in

quarantine

B Lal, Shashi Bhalla

10:20-11:00 hrs Detection and salvaging of hidden infestation of

bruchids in seeds

Shashi Bhalla, Kavita Gupta, Charan Singh

ii

11:00-11:45 hrs Management of insects and mites in seeds in

quarantine

Manju Lata Kapur and Kavita Gupta

11:45-13:00 hrs Quarantine processing for transgenics (Viewing of

CD)

Kavita Gupta

13:00-14:00 hrs Lunch

14:00 hrs Departure to Pantnagar

Sunday April 6

09:30-10:30 hrs Visit to University Library

Monday April 7

09:30-10:30 hrs Screening bio-control agents for control of seed

borne pathogen

Dr. U.S. Singh

10:30-11:30 hrs Resource conservation techniques in seed crop Dr. K.P. Singh

DEEd.


11:45-13:00 hrs Agronomic management for seed quality Dr. R.S. Verma

13:00-14:30 hrs Lunch

14:30-15:30 hrs Seed-borne Diseases and their management of Rice

Dr. A.P. Sinha


15:45-17:00 hrs Role of biotechnology in seed health management Dr. Anil Kumar

Tuesday April 08

09:30-10:30 hrs Quality Control arrangements in the seed

production

Dr. Deepak Pandey, TDC

10:30-11:30 hrs Contribution of UA Seed & TDC in the prosperity of

farmers

Dr. H.K. Singh , TDC


11:45-13:00 hrs Insect pest of seeds under storage and their

management

Dr. S.N. Tewari

13:00-14:30 hrs Lunch

14:30-15:30 hrs Role of university in seed production and

popularization of varieties

Dr. S.C. Mani


15:45-17:00 hra Group Photograph

Wednesday April 09

09:30-10:30 hrs Smut ,bunts and ergots their significance and

management in seed crop

Dr. R.C. Sharma, PAU

10:30-11:30 hrs Production of quality seed in tree species Dr. Salil Tewari


11:45-13:00 hrs Seed health management for fungal and bacterial diseases of potato

Dr. V.S. Pundhir

13:00-14:30 hrs Lunch

14:30-17:00 hrs Electron Microscopy-lab visit 107 Heritage Hall College of V.Sc.

Dr. Balwinder Singh

Thursday April 10

09:30-11:00 hrs Seed health testing in retrospect Dr. A.K. Gaur, New Delhi


iii

11:30-13:00 hrs Forest Seed Health Management Dr. Y.P. Singh, Dehradun

13:00-14:30 hrs Lunch

14:30-15:30 hrs Coordination between DNA technique and seed

industry

Dr. S. Marla, CBSH


15:45-17:00 hrs Methods for production of disease-free seed in

cereals

Dr. M.K. Nautiyal

Friday April 11

09:30-10:30 hrs Delivering new technologies through seeds ensuring health and productivity of crops.

Dr. R.D. Kapoor, New Delhi

10:30-11:30 hrs Trends in Indian Agriculture Dr. B.V. Singh


11:30-13:00 hrs How to analyse a seed sample for seed health Dr. A.K. Gaur, New Delhi

13:00-14:30 hrs Lunch

14:30-15:30 hrs Communication skills for teaching professionals

Contd.....

Dr. B. Kumar


15:45-17:00 hrs Communication skills for teaching professionals Dr. B. Kumar

Saturday April 12

09:30-10:30 hrs Seed and Agri business Dr. V.P.S. Arora, Dean CABM

10:30-11:30 hrs Approaches for health seed production in

sugarcane

Dr. O.K. Sinha, Lucknow


10:45-13:00 hrs Diagnosis of red rot and smut pathogens in

sugarcane for production of health seed

Dr. O.K. Sinha, Lucknow

13:00-14:30 hrs Lunch

14:30-15:30 hrs Role of cultural practices in management of seed

borne diseases

Dr. R.P. Awasthi


15:45-17:00 hrs Visit to seed processing plant TDC Haldi

Sunday April 13

09:30-10:30 hrs University Library- updating the literature

Monday

April 14

09:30-10:30 hrs Recent advances in cucurbits breeding & seed

production techniques

Dr. D.K. Singh

10:30-11:30 hrs Use of Agrometeorology in quality seed production Dr. N.S. Murty


11:45-13:00 hrs Management of seed borne bacterial disease in

seed production plots

Dr. Y. Singh

13:00-14:30 hrs Lunch

14:30-17:00 hrs Epidemiological Approaches to Disease

Management through Seed Technology & Practical

exercise on seed pathology

Dr. K. Vishunavat

iv

Tuesday April 15

09:30-10:30 hrs Management of seed crops through indigenous

technologies- an alternative to small and marginal

farmers

Dr. J. Kumar

10:30-11:30 hrs Strategies for regulation of seed borne diseases in

organic farming

Dr. R.L. Agrawal


11:45-13:00 hrs Seed treatment a new challenge in organic seed

production

Dr. R.L. Agrawal

13:00-14:30 hrs Lunch

14:30-15:30 hrs Aflatoxin in maize seeds Dr. S.C. Saxena


15:45-17:00 hrs Departure to Patwadangar/Majhera

Wednesday April 16

Visit to Patwadangar/Majhera

19:00 hrs. Return to Pantnagar

Thursday April 17

09:30-10:30 hrs Presentation by Participants

10:30-11:30 hrs Presentation by Participants


11:45-13:00 hrs Panel Discussion

13:00-14:30 hrs Lunch

14:30-17:00 hrs Closing and Valedictory Function

v

centre of advanced studies in plant pathology - citeseerx

Documents