WELCOME

Department of AgronomyInstitute of Agricultural Science

Banaras Hindu University, Varanasi

SEMESTER SEMINAR TOPIC

Name : Manoj KumarM.Sc. (Ag) AgroforestryID : AGF-14205

Supervisor : Dr. Rajesh Kumar Singh

Co-supervisor: Dr. Mahendra Singh

Effect of Various Weed Control Methods on Yield and Yield Components of Wheat Under Different Cropping Patterns

Contents Introduction

Weed

Weed management

Principle of weed management

INTRODUCTION

WEED

“ Weed is an unwanted plant growing where is not desired.’’

- Jethro Tull Unwanted undesirable plant that interfere

with the utilization of land ,water resources and thus adversely affect the crop production and human welfare.

Characteristics of weed:-

They thrive well even under adverse condition. They spread vegetatively . Able to regenerate lost plant. Compete with cultivated plant. Produce enormous number of weed. Ets seed remain viable for many year. All seed of weed mature simultaneously.

Weed management

The process of limiting weed infestation, so that crop can be grown profitably or other operations can be conducted efficiently

Principle of weed management

Weed management

Prevention Eradiation Control

Prevention

It is a long term planning so that the weeds could be controlled or managed more effectively and economically than is possible where these are allowed to disperse freely.

Following preventive control measures are suggested for adoption wherever possible & practicable.

Eradication

It infers that a given weed species, its seed & vegetative part has been killed or completely removed from a given area & that weed will not reappear unless reintroduced to the area.

Control

• In control methods, the weeds are seldom killed but their growth is severely restricted, the crop makes a normal yieldCONTROL

PHYSICAL MAICHENICAL CULTURAL CHEMICAL BIOLOGICA

L

Physical and Mechanical methodI. Tillage

II. Hoeing:

III. Hand Weeding

IV. Mowing

V. Burning

VI. Flooding

VII. Grazing

VIII.

Tillage Tillage removes weeds from the soil resulting in their

death. It may weaken plants through injury of root and stem pruning, reducing their competitiveness or regenerative capacity.

Hand weeding: It is done by physical

removal or pulling out of weeds by hand or removal by implements called khurpi, which resembles sickle

Hoeing :

Hoe has been the most appropriate and widely used weeding tool for centuries. It is however, still a very useful implement to obtain results effectively and cheaply.

Sickling and Moving: Sickling is also done by hand with the

help of sickle to remove the top growth of weeds to prevent seed production and to starve the underground parts.Mowing is a machine-operated practice mostly done on roadsides and in lawns

Burning:

Burning or fire is often an economical and practical means of controlling weeds.

Flooding::

Flooding kills plants by reducing oxygen availability for plant growth. The success of flooding depends upon complete submergence of weeds for longer periods.

Grazing:

The repeated removal of weed top growth by grazing animals, like close mowing, prevents seed formation andgradually weakens underground parts.

Cultural

i. Field preparation ii. Crop Rotationsiii. Maintenance of optimum plant populationiv. Mulching

Several cultural practices like tillage, planting, fertilizer application, irrigation etc., are employed for creating favorable condition for the crop. These practices if used properly, help in controlling weeds

The field has to be kept weed free. Flowering of weeds should not be allowed. This helps in prevention of build up of weed seed population.

Field preparation:

Crop rotation:

The possibility of a certain weed species or group of species occurring is greater if the same crop is grown year after year

Maintenance of optimum plant population:

Lack of adequate plant population is prone to heavy weed infestation, which becomes, difficult to control later

Mulch is a protective covering of material maintained on soil surface. Mulching has smothering effect on weed control by excluding light from the photosynthetic portions of a plant and thus inhibiting the top growth.

Mulching:

3. Chemical methodUsing chemicals, generally referred as herbicides, for the control of weeds is called chemical weed control. In 1944 - discovery of 2,4-D Na salt as a land mark in herbicide usage

Biological methodUse of living organism’s viz., insects, disease organisms, herbivorous fish, snails or even competitive plants for the control of weeds is called biological control

Treatments CP1 CP2 CP3 CP4 WC1 (Weedy Check)

WC2 (Hand Weeding at 20 and 40 DAS) WC3 (Mechanical Weeding at 20 DAS)

WC4 (Chemical Weeding at 2-3 leaf stage of weeds)WC5 (Mechanical Weeding at 20 DAS + Hand Weeding at 50 DAS)

12201.25

23697.25

13961.50

15388.30

17725.00

50304.25

72247.77

61398.25

64172.82

68549.48

45725.78

66641.77

61021.95

64313.99

66595.25

40147.58

60972.75

48588.75

52737.49

61970.27

Net benefit of various Cropping Patterns under different weed control methods

CP1= Wheat - Fallow – Wheat, CP2= Wheat - Corn – Wheat, CP3= Wheat - Mungbean – Wheat, CP4= Wheat - Cowpeas – Wheat

Integrated weed management