UNIVERSITI PUTRA MALAYSIA

COMPARATIVE STUDY OF DIFFERENT YIELD STIMULATION SYSTEMS ON YOUNG TREES OF HEVEA CLONE RRIM 901 PANEL

BO-1

MOHD AKBAR BIN MD SAID

FP 2003 28

COMPARATIVE STUDY OF DIFFERENT YIELD STIMULATION SYSTEMS ON YOUNG TREES OF HEVEA CLONE RRIM 901 PANEL DO-l

By

MOHD AKBAR BIN MD SAID

Thesis Submitted to the School of Graduate Studies, Universiti Putra Malaysia, in Fulfillment

of the Requirements for the Degree of Doctoral of Philosophy

December 2003

Abstract of thesis presented to the Senate of Universiti Putra Malaysia in Fulfillment of the requirement for the degree of Doctor of Philosophy

COMPARATIVE STUDY OF DIFFERENT YIELD STIMULATION SYSTEMS ON YOUNG TREES OF HEVEA CLONE RRIM 901 PANEL DO-l

By

MOHD AKBAR BIN MD SAID

December 2003

Chainnan Associate Professor Mohd. Fauzi bin Ramlan, Ph.D.

Faculty Agriculture

The emphasis of the study is to evaluate the resporise of young Hevea trees to a

new method of stimulation, REACTORRIM technique, developed by the Rubber

Research Institute of Malaysia (RRIM) in 1 990. The main objective of the development

ofREACTORRIM method of stimulation is to address the problem of shortage of skilled

tappers to tap trees according to the conventional tapping system. REACTORRIM

technique, which employs a concept of direct supply of ethylene into the laticiferous

tissue at a slow but continuous rate, is effective for increasing the yield response of

premium and old rubber trees.

Young Hevea trees clone RRIM 901 , panel BO-I responded negatively to the

method of stimulation irrespective of methods of latex extraction, age of tree and history

of tapping. The results showed that the negative effects were seen earlier on the cut

systems than on the puncture tapping system. The bole growth quantified during the

ii

study period was shown not to be solely the manifestation of cambial activity but also the

continuous formation of layers of unproductive dry tissue.

Despite severe bark reaction, the puncture tapping system responded more

favorably to the REACTORRIM technique. All the experiments showed a consistent

trend, where a higher dosage of ethylene was required for the puncture tapping system.

The results confirmed the inverse relationship between dosage of ethylene and number of

latex vessels severed during tapping.

The effect of methods of stimulation on the status of elements and selected

physiological parameters was markedly observed. Removal of nutrients was higher in the

REACTORRIM stimulated trees. The high removal of nutrients and low content of

sucrose can be associated with the downward trend of yield of the Hevea trees used.

There was no significant difference between the status of nutrients during the moderate

and high yielding periods of the year.

Sucrose appeared as the most suitable parameter to be used as stress indicator for

young Hevea trees, clone RRIM 901, panel BO-I used in this study. The content of

sucrose was influenced by the interaction effect between the methods of stimulation and

latex extraction. The content of sucrose of the REACTORRIM stimulated treatments was

consistently lower than the non-REACTORRIM stimulated treatments, except for the

puncture tapping system.

iii

Young Hevea trees clone RRIM 901, panel BO-1 used in the study responded

negatively to REACTORRIM method of stimulation with drastic reduction in latex

production, low content of sugar, high incidence of tapping panel dryness and

considerably high loss of nutrient from latex and after-shaved bark. The yield profile

obtained from the study showed that there was no sign of yield recovery indicating

collapse of lactiferous system and impaired biosynthetic processes. Findings established

from the study continned that REACTORRIM technique is not suitable as yet, for

commercial uptake on young Hevea trees. For young Hevea trees, the most suitable

exploitation system is the conventional 1I2S d/3 system with or without mild ethephon

stimulation.

IV

Abstrak tesis dikemukakan kepada Senat Universiti Putra Malaysia

Sebagai memenuhi kepeduan untuk ijazah Doktor Falsafah

KAJIAN PERBANDINGAN PELBAGAI SISTEM PERANGSANGAN BASIL KE ATAS POKOK HEVEA MUDA KLON RRIM 901 PANEL DO-l

Oleh

MOHD AKBAR B MD SAID

Disember 2003

Pengerusi Professor Madya Mohd. Fauzi bin Ramlan, Ph.D.

Fakulti Pertanian

Penumpuan kajian ialah untuk menilai respon pokok-pokok Hevea muda kepada

kaedah perangsangan teknik REACTORRIM yang dicipta oleh Institut Penyelidikan

Getah Malaysia (RRIM) pada tahun 1990. Tujuan utama menghasilkan teknik

perangsangan REACTORRIM ialah untuk menangani masalah kekurangan penoreh

mahir untuk menoreh sistem torehan konvensional. Teknik perangsangan

REACTORRIM menggunakan konsep membekal gas etilina secara berterusan ke tisu

'laticiferous' dengan kadar pelepasan yang perlahan adalah berkesan untuk meningkatkan

respon hasil pokok-pokok getah premium dan pokok getah tua. Sungguhpun demikian,

kaedah perangsangan REACTORRIM belurn lagi disyorkan kepada pokok-pokok Hevea

muda.

Teknik perangsangan REACTORRIM tidak sesuai untuk pokok Hevea muda,

klon RRIM 901 , panel BO-l, yang menunjukkan respon hegatifke atasnya tidak mengira

v

kaedah pengeluaran lateks, umur pokok dan sejarah penorehan. Pertumbuhan batang

pokok yang dirangsang dengan teknik REACTORRIM yang direkodkan disepanjang

kajian ini bukan merupakan manifestasi aktiviti kambium tetapi juga disebabkan oleh

kesan pembentukan lapisan kulit kering yang tidak produktif secara berterusan.

Walaupun reaksi kulit keterlaluan, sistem torehan cucuk menunjukkan respon

yang lebih menggalakkan kepada keadah perangsangan REACTORRIM. Kesemua

percubaan menunjukkan corak yang seragam di mana dos etelina yang tinggi diperlukan

untuk sistem torehan cucuk Keputusan ini adalah selaras dengan perhubungan yang

bertentangan di antara dos etilina dengan bilangan saluran lateks yang tercedera apabila

ditoreh.

Kesan kaedah perangsangan ke ats status unsur pemakanan mineral dan bukan

mineral dan ke atas status parameter fisiologi lateks terpilih adalah sangat ketara.

Pengaliran keluar unsur pemakanan terutamanya unsur pemakanan makro dari kulit yang

ditoreh dan dari lateks adalah tinggi pada pokok-pokok yang dirangsang dengan teknik

REACTORRIM. Pengaliran unsur pemakanan yang tinggi adalah berkait rapat dengan

corak penurunan hasil torehan pokok Hevea muda yang digunakan dalam kajian ini.

Keputusan yang didapati menunjukkan tiada perbezaan ketara di antara status unsur

pemakanan ketika musim berpenghasilan sederhana dan tinggi dalam tahun yang sama.

Sukrosa merupakan parameter yang paling sesuai untuk digunakan sebagai

petanda 'stress' bagi pokok Hevea muda, klon RRIM 901 , panel BO-l , yang digunakan

VI

di dalam kajian ini. Kandungan sukrosa dipengaruhi oleh kesan interaksi di antara kaedah

perangsangan dengan kaedah pengeluaran lateks.

Kandungan sukrosa rawatan yang dirangsang dengan teknik REACTORRIM

adalah sentiasa rendah dati kandungan gula rawatan yang tidak dirangsang dengan teknik

REACTORRIM, kecuali sistem torehan cucuk. Pokok getah muda klon RRIM 901 , panel

BO-l yang digunakan dalam kajian ini menunjukkan respon negatif kepada teknik

REACTORRIM dengan kejatuhan pengeluaran lateks yang amat ketara, kejadian

kekeringan kulit dan kehilangan kandungan unsur pemakanan yang agak tinggi dari

lateks dan kulit yang ditoreh berbanding torehan konvensional.

Profil hasil yang ditunjukkan dari percubaan ini menunjukkan tiada tanda-tanda

pemulihan ke atas pengeluaran hasi1.di masa hadapan dan ini berkemungkinan tinggi

disebabkan oleh sistem 'laticiferous' pokok-pokok yang terlibat tidak berfungsi serta

gangguan ke atas sistem biosintisis. Keputusan kajian menjurus kepada kesimpulan iaitu

teknik REACTORRIM masih belum sesuai untuk diamalkan secara komersil tidak

mengira kaedah pengeluaran hasil, umur pokok dan sejarah penorehan. Untuk pokok

Hevea muda, sistem eksploitasi yang paling sesuai ialah sistem torehan konvensional

1I2S d/3 dengan atau tanpa penggunaan etefon dengan kekuatan yang rendah.

Vll

ACKNOWLEDGEMENT

The completion of this thesis is made possible due to the blessing of the Almighty Allah.

The author wish to express sincere appreciation and gratitude to the followings who have

supported and assisted in the graduate study leading to a PhD degree at Universiti Putra

Malaysia, Serdang, Selangor:

Y Bhg Dato' Hamid Sawal, Director General of MRB and Y Bhg Dato' Dr Abdul Aziz

Sheikh Abdul Kadir, former Director General of the Malaysian Rubber Board (MRB) for

their encouragement, advice and support.

The MRB Board for allowing the author to pursue the graduate study on part-time basis.

Dr Wan Abdul Rahaman bin Wan Yaacob, former Assistant Director (Biology) ofMRB

for his support.

Associate Professor Dr Mohd Fauzi Ramlan, Chairman of the committee of the author's

graduate study, for his invaluable suggestions and advice, encouragement, patience and

understanding that enable the author to complete the study despite long duration mainly

because of official workload that the author has to attend.

Vlll

Dr Jamal b Talib, Dr Yeang Hoong Yeet and Dr S. Sivakumaran for serving as members

of committee of the author's graduate study and for their advice, suggestions and

encouragement.

Staff of Crop Management Unit notably En. K. Jeyakumar, En. Mohd Noh Hj Yunus, En.

Muthugaruppan, En. Rajan, En. Mazlan, En. K. Arumugam and En. Ramamoorthy for

their technical support both in the field and in the laboratory. Their assistance is deeply

appreciated. Appreciation is also extended to En. Shah of the Agriculture Faculty, UPM

for his technical asisstance.

Dr Hj Abdul Ghani Ibrahim and En. Ishak Said for allowing the use young Hevea trees

clone RRIM 901 , panel BO-lin Field 1 9, RRIES Sg. Buloh, Selangor, Field 1 12 and

Field 1 03-108 in Pelepah Division ofRRIES Kota Tinggi, Johore respectively.

Statisticians from the Information Technology Unit of MRB specifically Tn Hj Mohd

Napi Daud and Siti Hawa Sulong and their staff Doyah and Hamzah for advice and

assistance in analysis of data generated from the study.

Finally to my mother, Parsah bte Omar, my wife Hasnah Abdul Manaf, my son, Mohd

Hatta and my daughter, Elisya Farha for their encouragement and patience throughout the

study period.

IX

I certify that an Examination Committee met on 30th December 2003 to conduct the final examination of Mohd Akbar bin Md Said on his Doctor of Philosophy thesis entitled "Comparative Study of Different Yield Stimulation Systems on Young Trees of Hevea Clone RRIM 901 (panel BO-I)" in accordance with Universiti Pertanian Malaysia (Higher Degree) Act 1980 and Universiti Pertanian Malaysia (Higher Degree) Regulations 1981. The Committee recommends that the candidate be awarded the relevant degree. Members of the Examination Committee are as follows :

Zakaria Wahab, Faculty of Agriculture Universiti Putra Malaysia (Chairman)

Mohd Fauzi bin Ramlan, Ph.D. Faculty of Agriculture Universiti Putra Malaysia (Member)

Jamal bin TaIib, Ph.D. Faculty of Agriculture Universiti Putra Malaysia (Member)

Yeang Hoong Yeet, Ph.D. Head, Biotechnology and Strategic Research Unit Malaysian Rubber Board (Member)

S. Sivakumaran, Ph.D. CEOlDirector RCP Trading and Consultancy Services (M) Sdn Bhd (Member)

Hubert Omont Ta80IPS3 Boulevard De La Lironde 34398 Montpellier Cedex 5, France (Independent Examiner)

x

J'---�r MAD NASIR SHAMSUDIN, Ph.D. ProfessorlDeputy Dean School of Graduate Studies Universiti Putra Malaysia

Date: 2 1 APR 2004

This thesis submitted to the Senate ofUniversiti Putra Malaysia and has been accepted as

fulfillment of the requirement for the degree of Doctor of Philosophy. The members of the Supervisory Committee are as follows:

Mohd Fauzi bin Ramlan, Ph.D. Faculty of Agriculture Universiti Putra Malaysia (Chainnan)

Jamal bin Talib, Ph.D. Faculty of Agriculture Universiti Putra Malaysia (Member)

Yeang Hoong Yeet, Ph.D. Head, Biotechnology and Strategic Research Unit Malaysian Rubber Board (Member)

S. Sivakumaran, Ph.D. CEOlDirector RCP Trading and Consultancy Services (M) Sdn Bhd (Member)

xi

AINI IDERIS, Ph.D. ProfessorlDean School of Graduate Studies Universiti Putra Malaysia

Date: 2 1 JUN 2004

DECLARATION

I hereby declare that the thesis is based on my original work except for quotations and citations which have been duly acknowledge. I also declare that it has not been previously or concurrently submitted for any other degree at UPM or other institutions.

Date:

xii

TABLE OF CONTENTS

Page

ABSTRAct ii v

viii ABSTRAK ACKNOWLEDGEMENTS APPROVAL SHEETS DECLARATION FORM LIST OF TABLES

x xii

xix xxv LIST OF FIGURES

LIST OF PLATES xxix xxx

xxxii LIST OF ABBREVIATIONS TAPPING NOTATION

CHAPTER

1

2

INTRODUCTION 1.1

LITERATURE REVIEW 2.1

2.1 Introduction of rubber in Malaysia 2.1 2.2 Establishment of rubber industry in the Peninsula 2.2 2.3 The structural changes and contribution of rubber industry 2.5 2.4 Objective of tapping 2.6 2.5 Factors influencing crop exploitation 2.8

2.5.1 Horticultural and agronomic practices 2.8 2.5.2 Tapping parameters 2.9 2.5.3 Anatomy and cytology of latex 2.10 2.5.4 Latex Physiology 2.13 2.5.5 Latex total solid content and dry rubber content 2.15 2.5.6 Plugging index and flow of latex 2.16 2.5.7 Turgor pressure diurnal and seasonal changes

in latex flow 2.19 2.5.8 Sucrose and latex invertase activity 2.21

2.6 Exploitation system 2.24 2.6.1 Concept and methods of latex extraction 2.24 2.6.2 Excision method of latex extraction 2.25 2.6.3 Incision method of latex extraction 2.28

2.7 Tapping systems for young rubber 2.31 2.7.1 Conventional tapping system 2.31 2.7.2 Puncture tapping system 2.33 2.7.3 Short cut system 2.36

2.8 Stimulating latex production 2.36

xiii

3

2.8.1 Physical injuring for stimulating latex flow 2.36 2.82 Use of chemical for stimulating latex flow 2.37 2.8.3 Use of ethylene gas for stimulating latex flow 2.40 2.84 Development of gaseous method of stimulation in

Malaysia 2.42 2.8.5 Role of ethylene in relation to production of rubber 2.43

2.9 Methods of ethephon application for the conventional tapping system commonly practiced by the NR industry of Malaysia 2.45 2.9. 1 Bark application method 2.46 2.9.2 Panel application method 2.47 2.9.3 Groove application method 2.48 2.9.4 Lace application method 2.48

2. 10 Method o f ethephon application for puncture tapping system 2.49 2.1 1 Yield response of young Hevea trees to ethephon stimulation 2.50

2.1 1 . 1 Yield response of cut system to exploitation system without stimulation 2.50

2.1 1 .2 Yield response of cut system to the conventional ethephon stimulation 2.51

2.1 1 .3 Yield response of incision method of latex extraction to the conventional ethephon stimulation 2.53

2.12 Status of nutrient drainage in relation to exploitation of Hevea trees 2.55 2.12.1 Nutrient drainage in leaf 2.55 2. 12.2 Nutrient drainage in latex 2.57 2. 12.3 Nutrient drainage in bark 2.58

GENERAL MATERIALS AND METHODS 3.1

3.1 Site description 3.1 3.2 Experimental design 3.1 3.3 Treatment combinations 3.2 3.4 Stimulation practices 3.3 3.5 Recording of parameters of tapping, stimulation and bole

grovvdh 3.4 3 .5. 1 Tapping yields 3.4 3.5.2 Dry rubber content 3 .6 3.5.3 Moisture content of bark 3.8-3.5.4 Bark consumption 3.8 3.5.5. Girth measurement 3.9 3.5.6 Incidence of tapping panel dryness 3.9

3.6 Analysis of data 3 . 1 0

xiv

4 RESPONSE OF 5-YEAR-OLD CLONE RRIM 901, PANEL BO-1 TO DIFFERENT EXPLOITATION SYSTEMS 4.1

4.1 Introduction 4. 1 4.2 Materials and methods 4.2 4.3 Results 4.5

4.3. 1 Seasonal change 4.5 4.3.2 Bole growth 4.6 4.3.3 Total tree productivity 4. 12 4.3.4 Proportion of latex and late drip 4.19 4.3.5 Land productivity 4.26 4.3.6 Dry rubber content 4.31 4.3.7 Bark reaction to REACTORRIM method of

stimulation 4.34 4.3.8 Bark consumption 4.39 4.3.9 Moisture content in the bark 4.40 4.3. 10 Incidence of tapping panel dryness 4.42

4.4 Discussion 4.43 4.4. 1 Tree productivity 4.43 4.4.2 Dry rubber content 4.45 4.4.3 Bark moisture content 4.47 4.4.4 Incidence of tapping panel dryness 4.48 4.4.5 Proportion of latex and late drip 4.50 4.4.6 Effect of wintering period 4.52

,

4.5 Conclusion 4.53

5 STUDY ON THE STATUS OF MACRO AND MICRO ELEMENTS IN LATEX, BARK AND LEAF OF CLONE RRIM 901 , PANEL BO-l TAPPED WITH DIFFERENT EXPLOITATION SYSTEMS 5.1

5.1 Introduction 5.1 5.2 Materials and methods 5.3

5.2 . 1 Determination of Nitrogen 5.6 5.2.2 Detennination of Phosphorus 5.6 5.2.3 Determination of Potassium (K), Magnesium (mg),

Manganese (Mn), Copper (Cu). Iron (Fe), Zinc (Zn) and Calcium (Ca) 5.7

5.3 Results 5.8· 5.3.l Nitrogen 5.8 5.3.1 Phosphate 5. 12 5.3.3 Potassium 5.16 5.3.4 Magnesium 5.20 5.3.5 Calcium 5.24 5.3.6 Copper 5.27 5.3.7 Manganese 5.30 5.3.8 Iron 5.34

xv

5.3.9 Zinc 5.36 5.3.10 Correlation between yield, DRC and mineral elements

status in leaf, bark and latex 5.40

5.4 Discussion 5.44

5.4.1 Leaf nutrient status of clone RRIM 901, panel BO-1, in relation to methods of latex extraction and stimulation 5.44

5.4.2 Drainage of nutrients from latex of clone RRIM 901, panel BO-1, in relation to methods of latex extraction and stimulation 5.45

5.4.3 Loss of nutrients from bark of clone RRIM 901, panel BO-l , in relation to methods of latex extraction and stimulation 5.49

5.4.4 Annual loss of elements 5.53 5.4.5 Annual bark shaved in relation to yield and nutrient

drainage 5.54 5.5 Conclusion 5.57

6 STUDY ON THE STATUS OF SELECTED PHYSIOLOGICAL LATEX PARAMETERS OF HEVEA TREES CLONE RRIM 901, PANEL BO-l, TAPPED WITH DIFFERENT EXPLOITATION SYSTEMS 6.1

6.1 Introduction 6.1 6.2 Materials and methods 6.3

6.2.1 Study site and sampling procedures 6.3 6.2.2 Field sampling 6.4 6.2.3 Determination of pH 6.5 6.2.4 Protocols for determination of sucrose, inorganic

phosphate, thiols and proline 6.5 6.3 Results 6.10

6.3.1 pH of latex 6.10 6.3.2 Thiols 6.13 6.3.3 Proline 6.18 6.3.4 Inorganic phosphate 6.24 6.3.5 Sucrose 6.29 6.3.6 Correlations among parameters of latex physiology 6.34

6.4 Discussion 6.38 6.4.1 Sucrose 6.38 6.4.2 pH 6.44 6.4.3 Thiols 6.46 6.4.4 Inorganic phosphate 6.48 6.4.5 Proline 6.50

6.5 Conclusion 6.52

xvi

7 EV ALUATION OF RESPONSE OF HEVEA TREES CLONE RRIM 901, PANEL BO·1, OPENED FOR TAPPING AT 10-YEAR-OLD TO DIFFERENT EXPLOITATION SYSTEMS 7.1

7.1 Introduction 7.1 7.2 Materials and methods 7.2 7.3 Results 7.4

7.3.1 Total tree productivity 7.4 7.3.2 Effect of wintering period on the tapping yield 7.10 7.3.3 Dry rubber content 7.1 I 7.3.4 Proportion of latex and late drip 7.12 7.3.5 Land productivity 7.17 7.3.6 Incidence of tapping panel dryness 7.19 7.3.7 Bark reaction to REACTORRIM method

of stimulation 7.25 7.4 Discussion 7.25

7.4.1 Influence of delayed opening of tapping on yield 7.26 7.4.2 Bark reaction of Hevea trees opened for tapping at

10-year-old to REACTORRIM method of stimulation 7.32 7.4.3 Influence of stimulation on the proportion of latex and

late drip 7.33 7.4.4 Development of tapping panel dryness 7.34

7.5 Conclusion 7.36

8 STUDY OF RESPONSE OF 10-YEAR-OLD HEVEA TREES CLONE RRIM 901, PANEL BO-1, PREVIOUSLY TAPPED FOR FOUR YEARS, TO DIFFERENT EXPLOITATION SYSTEMS 8.1

8.1 Introduction 8.1 8.2 Materials and methods 8.3 8.3 Results 8.4

8.3.1 Total tree productivity 8.4 8.3.2 Influence of surface area on gltlt 8.6 8.3.3 Dry rubber content 8.8 8.3.4 Proportion of latex and late drip 8.11 8.3.5 Land productivity 8.13

8.3.6 Bark reaction to REACTORRIM method of stimulation 8.14 8.4 Discussion 8.15

8.4.1 Yield response to stimulation in relation to previous tapping 8.15

8.4.2 Influence of previous tapping on dry rubber content 8.18 8.4.3 Bark reaction and tapping panel dryness in relation to

response of clone RRIM 901, panel BO-1, previously tapped for four years to different method of stimulation 8.20

8.5 Conclusion 8.21

xvii

9 GENERAL DISCUSSION AND CONCLUSIONS

9.1 Conventional method of stimulation versus gaseous

9.1

method of stimulation 9.1 9.2 Tapping parameters as influenced by age, tapping panel and

tapping history 9.3 9.3 Growth and bark reaction of young Hevea trees, in response

to conventional and gaseous method of stimulation 9.10 9.4 Status of mineral elements of young Hevea trees stimulated

with conventional and gaseous method of stimulation 9.12 9.5 Status of selected physiological parameters of young Hevea

trees stimulated with conventional and gaseous methods of stimulation 9.18

REFERENCES Rl

APPENDIX A B C

REACTORRIM method of stimulation Details of treatment combinations Additional tables

BIODATA OF THE AUTHOR

xviii

Al A2 A3

Bl

LIST OF TABLES

Table Page

1 Rainfall pattern and average temperature at RRIES Sg. Buloh in 1 996 and 1 997 4.3

2 Average bole growth of clone RRIM 901 , panel BO-l, in Field 19, RRIES Sg. Buloh 4.8

3 Status of incidence of tapping panel dryness based on the number of trees and length of cut over 24 months 4.43

4 Pearson correlation coefficient of mean gltJt with leaf, latex and bark mineral content of clone RRIM 901 , panel BO-l , in Field 19, RRIES Sg. Buloh, Selangor DE 5.41

5 Pearson correlation coefficient of mean DRe with leaf, latex and bark mineral content of clone RRIM 901 , panel SO-I, in Field 1 9, RRIES Sg. Buloh, Selangor DE 5.42

6 Pearson correlation coefficients between yield (gltJt) and latex physiological parameters of clone RRIM 901 , panel BO- 1 , at different yielding periods of 1 996 and 1 997 6.35

,

7 Pearson correlation coefficients between pH and other latex physiological parameters of clone RRIM 901 , panel BO- 1 , at different yielding periods of 1 996 and 1 997 6.36

8 Pearson correlation coefficient between thiols and other latex physiological parameters of clone RRIM 901 , panel BO-l, at different yielding periods of 1996 and 1997 6.37

9 Pearson correlation coefficient between praline, Pi and sucrose and between Pi and sucrose of clone RRIM 901 , panel SO-I, at different yielding periods of 1 996 and 1 997 6.37

1 0 Monthly rainfall of 1996 and 1997 at Pelepah Division, RRIES Kota Kota Tinggi, Johore DT 7.3

1 1 Progress of incidence of tapping panel dryness of clone RRIM 901, panel BO-l, open for tapping at 1 0-year-old , Field 1 12 Pelepah Division, RRIES Kota Tinggi, Johore DT 7.20

xix

12 Percentage of tapping panel dryness expressed in term of

length of dry patch over the total length of cut after 18 month of tapping 7.23

1 3 Total gltlt per mm2 of tapped bark of Hevea trees previously tapped for four years, clone RRIM 901, panel BO-l in Field 103-108, Pelepah Division, RRIES Kota Tinggi, Johore DT 8.7

14 ANOVA (Mean square) of bole circumference of clone RRIM 901, panel BO-l, over 24 months in Field 19, RRIES Sg. Buloh, Selangor DE A3.2

1 5 ANOV A (Mean square) of total gltlt of clone RRIM 901 , panel BO-1 , over 24 months in Field 1 9, RRIES Sg. Buloh, SelangorDE A3.3

16 Contrast (p<0.05) of total gltlt of 5-year-old clone RRIM 901 , panel BO-1, over 24 months in Field 19, RRIES Sg. Buloh, SelangorDE A3.4

17 ANOVA (Mean square) of gltlt of latex and late drip of 5-year-old clone RRIM 901 , panel BO-l, over 24 months in Field !9, RRIES Sg. Buloh, Selangor DE A3.5

1 8 ANOV A (Mean square) ofkglha of 5-year-old clone RRIM 901 , panel BO-l , over 24 months in Field 19, RRIES Sg. Buloh, Selangor DE A3.6

1 9 Contrast (p<0.05) for kglha of 5-year-old clone RRIM 901 , panel BO-l , over 24 months in Field 19, RRIES Sg. Bulob, SelangorDE A3.7

20 ANOVA (Mean square) ofDRC of 5-year-old clone RRIM 901 , panel BO-l , over 24 months in Field 19, RRIES Sg. Buloh, Selangor DE A3.8

21 Contrast (p<0.05) for DRC of5-year-old clone RRIM 901 , panel BO-l, over 24 months in Field 1 9, RRIES Sg. Buloh, SelangorDE A3.9

22 ANOV A (Mean square) of bark consumption of 5-year-old clone RRIM 901 , panel BO-l , over 24 months (cml24 months) in Field 19, RRIES Sg. Buloh, Selangor DE A3. 10

xx

23 ANOVA (Mean square) of bark moisture content of 5-year-old clone RRIM 901, panel BO-l, during the low, moderate and high yielding periods of 1997 in Field 19, RRIES Sg. Buloh, SelangorDE A3.ll

24 ANOVA (Mean square) of Nitrogen content (% weight) in leaf, latex and bark of clone RRIM 901, panel BO-1, in Field 19, RRIES Sg. Buloh, Selangor DE A3.12

25 Contrast (p<0.05) for Nitrogen content in leaf, latex and bark of clone RRIM 901, panel BO-1, Field 19 RRIES Sg. Buloh, SelangorDE A3.13

26 ANOVA (Mean square) of Phosphorus content (% weight) in leaf, latex and bark of young Hevea trees clone RRIM 901, panel BO-1 in Field 19, RRIES Sg. Buloh, Selangor DE A3.14

27 Contrast (p<0.05) for the Phosphorus content in leaf, latex and bark of clone RRIM 901, panel BO-l, RRIES Sg. Buloh, SelangorDE A3.l5

28 ANOV A (Mean square) of Potassium content (% weight) in leaf, latex and bark of clone RRIM 901, panel BO-l, in Field �9, RRIES Sg. Buloh, Selangor DE A3.l6

29 Contrast (p<0.05) for the content of Potassium in leaf, latex and bark of clone RRIM 901, panel BO-1, Field 19 RRIES Sg. Buloh Selangor DE A3.17

30 ANOVA (Mean square) of Magnesium content (% weight) in leaf, latex and bark of young Hevea trees clone RRIM 901, panel BO-l, in Field 19, RRIES Sg. Buloh, Selangor DE A3.18

31 Contrast (p<0.05) for the content of Magnesium in leaf, latex and bark of clone RRIM 901, panel BO-l, Field 19, RRIES Sg. Buloh, Selangor DE AJ.19

32 ANOV A (Mean square) of Calcium content (ppm) in the leaf, latex and bark of clone RRIM 901, panel BO-1, in Field 19, RRIES Sg. Buloh, Selangor DE A3.20

33 Contrast (p<O.05) for the Calcium content in leaf, latex and bark of clone RRIM 901, panel BO-1, RRIES Sg. Buloh, SelangorDE A3.21

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34 ANOVA (Mean square) of Copper content (ppm) in leaf, I latex and bark of clone RRIM 901, panel BO-1, in Field 19, RRIES Sg. Buloh, Selangor DE A3.22

35 Contrast (p<0.05) for the content of Copper in leaf, latex and bark of clone RRIM 901, panel BO-1, in Field 19, RRIES Sg. Buloh, Selangor DE A3.23

36 ANOVA (Mean square) of Manganese content (ppm) in in leaf, latex and bark of clone RRIM 901, panel BO-l, in Field 19, RRIES Sg. Buloh, Selangor DE A3.24

37 Contrast (p<0.05) for the content of Manganese in leaf, latex and bark of clone RRIM 901, panel BO-l, in Field 19 RRIES Sg. Buloh Selangor DE A3.25

38 ANOV A (Mean square) of Iron content (ppm) in leaf, latex and bark of clone RRIM 901, panel BO-l, in Field 19, RRIES Sg. Buloh, Selangor DE A3.26

39 Contrast (p<0.05) for the content of Iron in leaf, latex and bark of clone RRIM 901, panel BO-1, in Field 19 IRRIES Sg. Buloh Selangor DE A3.27

40 ANOVA'(Mean square) of Zinc content (ppm) in leaf, latex

and bark of clone RRIM 901, panel BO-1, in Field 19, RRIES Sg. Buloh A3.28

41 Contrast (p<0.05) for the content of Zinc in leaf, latex and bark of clone RRIM 901, panel BO-l, in Field 19, RRIES Sg. Buloh, Selangor DE A3.29

42 ANOV A (Mean square) of pH (1996 and 1997) of clone RRIM 901, panel BO-l, in Field 19, RRIES Sg. Buloh SelangorDE A3.30

43 ANOV A (Mean square) of thiols (1996 and 1997) of clone RRIM 901, panel BO-l, in Field 19, RRIES Sg. Buloh, Selangor DE A3.31

44 ANOVA (Mean square) of proline (1996 and 1997) of clone RRIM 901, panel BO-1, in Field 19, RRIES Sg. Buloh SelangorDE A3.32

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45 ANOVA (Mean square) of inorganic phosphate (1996 and 1997) of clone RRIM 901, panel BO-1, in Field 1 9, RRIES Sg. Buloh, Selangor DE A3.33

46 ANOVA (Mean square) of sucrose (1996 and 1997) of clone RRIM 901, panel BO-l, in Field 1 9, RRIES Sg. Buloh, Selangor DE A3.34

47 Contrast (p<0.05) of sucrose content (mM/L) of clone RRIM 901, panel BO-l, in Field 1 9, RRIES Sg. Buloh Selangor DE A3.35

48 ANOV A (Mean square) of total glt/t and DRC (18 months) of clone RRIM 901, panel BO-l, opened for tapping at 10-year-old, in Field 112, Pelepah Division, RRIES Kota Tinggi, lohore DT A3.36

49 Contrast (p<0.05) of total glt/t and DRC (18 months) of clone RRIM 901, panel BO- l , in Field 112, Pelepah Division, RRIES Kota Tinggi, lohore DT A3.37

50 ANOVA (Mean square) of total glt/t (12 months and 13th to 18th month) of Hevea trees opened for tapping at 10-year-old, clone RRIM 901 , panel BO-l , in Field 112, Pelepah Division, RRIES Kota Tinggi, lohore DT A3.38

51 ANOVA (Mean square) of average latex and LD glt/t (18 months) of Hevea trees opened for tapping at to-year-old, clone RRIM 901, panel BO- l , in Field 112, Pelepah Division, RRIES Kota Tinggi, lohore DT A3.39

52 ANOVA (Mean square) ofkglha (12 months and 13th to 18th month) of Hevea trees opened for tapping at 10-year-old, clone RRIM 901, panel BO-l, in Field 103-108, Pelepah Division, RRIES Kota Tinggi, lohore DT A3.40

53 ANOVA (Mean square) of total glt/t and DRC (12 months) of Hevea trees previously tapped for four years, clone RRIM 901, panel BO-l , in Field 103-108, Pelepah Division, RRIES Kota Tinggi, lohore DT A3.41

54 Contrast (p<0.05) for total glt/t and DRC (1 2 months) of clone RRIM 901, panel BO-l , in Field t03-t08, Pelepah Division, RRIES Kota Tinggi, lohore DT A3.42

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55

56

ANOVA (Mean square) oflatex and LD glt/t (12 months) of Hevea trees previously tapped for four years, clone RRIM 901, panel BO-1, in Field 103-108, Pelepah Division, RRIES Kota Tinggi, Johore DT

ANOV A (Mean square) ofkglha/year of Hevea trees previously tapped for four years, clone RRIM 901, panel BO-l, in Field 103-108, Pelepah Division, RRIES Kota Tinggi, Tinggi, Johore DT

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A3.43

A3.44