RESPONSE OF COTTON CULTIVARS TO SOWING TIME,

PLANT SPACING AND NITROGEN APPLICATION

BY

MUHAMMAD NAVEED AFZAL

M.sc (Hons) Agronomy

A Thesis submitted in partial fulfillment of the requirements for the degree of

DOCTOR OF PHILOSOPHY

IN

AGRONOMY

DEPARTMENT OF AGRONOMY
BAHAUDDIN ZAKARIYA UNIVERSITY
MUTAN, PAKISTAN

i
ii
 DEDICATION

Dedicated to
THE HOLY PROPHET (PBUH)

iii
 ACKNOWLEDGEMENTS
To start with, I owe my success for completing my Ph.D. studies to

All appreciation and thanks for almighty Allah, the magnificent and merciful and His
Prophet Muhammad (PBUH) who is forever a torch of guidance and knowledge for
humanity.

It is a pleasure to thank the many people who made this thesis possible.

It is difficult to overstate my gratitude to my Ph.D. Supervisor, Dr. Hakoomat Ali, Department of

Agronomy, University College of Agriculture, Bahauddin Zakariya University, Multan, with his
enthusiasm, inspiration, and great efforts to explain things clearly and simply, he helped to make
agronomy easy for me. Throughout my thesis-writing period, he provided encouragement, valued
advices, good teaching, friendly company, and lots of good multi-dimensional ideas. Love to my
respected Supervisor loves kids (Sara and Bilal) who surely would have missed their loving
father during business of my studies.

I wish to express my deep sense of gratitude to Dr. Dilbaugh Muhammad, Head Department of
Agronomy, Dr. Fiaz Ahmad, Department of Physiology Central Cotton Research Institute,
Multan and Dr. Shakeel Ahmad, Department of Agronomy, University College of Agriculture,
Bahauddin Zakariya University, Multan who constantly encouraged me and gave valuable
suggestions for initiating this work and providing scientific guidance. His affectionate attitude
remained a source of interest throughout the course of my studies. This research work has left an
unforgettable impression in my mind. I owe him a lot more than this brief tribute. I am also
indebted to my supervisor.

I wish to thank my colleagues and friends especially Qayyum, Ilyas, Saeed, Ilyas and Raheel for

their moral help and co-operation at the time of need.

Ordinary words of gratitude do not truly encompass that love and guidance extended by my
mother, sisters and brothers. Love to my kids (Shehan and Rohan) who always missed me during
study and special thanks to my wife for instigation of higher studies, encouragement and
sacrifices. May they all live long to see all my dreams being fulfilled (Aamin).

I would like to like to appreciate priceless guidance and help given by the laboratory staff
especially Mr. Ali Ahmad.

NAVEED

iv
 CONTENTS
Title Page No.
ACKNOWLEDGEMENT iv
TABLE OF CONTENTS v
LIST OF TABLES vi
LIST OF FIGURES xiv
LIST OF APPENDICES xix
LIST OF ABBREVIATIONS xx
01
1 Introduction
04
2 Review of Literature
28
3 General Materials and Methods
4 Results and Discussion
4.1 Cultivars response to sowing time and 36
plant spacing.
4.1.1 Materials and Methods 37
4.1.2 Results 38
4.1.3 Discussion 80
4.2 Cultivars response to plant spacing and 83
nitrogen application
4.2.1 Materials and Methods 84
4.2.2 Results 85
4.2.3 Discussion 170
4.3 Effect of nitrogen levels and plant 174
spacing on cotton productivity
4.4.1 Materials and Methods 174
4.4.2 Results 175
4.4.3 Discussion 209
4.4 Plant structure and seed cotton yield of 212
cultivars as influenced by nitrogen
fertilizer
4.4.1 Materials and Methods 212
4.4.2 Results 213
4.4.3 Discussion 218
General Discussion 220
Summary 225
Conclusion 228
References 229

v
 LIST OF TABLES

TABLE DESCRIPTION PAGE

1 Physical and Chemical analysis of the experimental site 29

(2004-2007).

2 Quality of canal and tube well water used for irrigation season 30

3 Chemical analysis of the experimental site (2004) 37

4 Chemical analysis of the experimental site (2005). 84

5 Chemical analysis of the experimental site (2006). 175

6 Chemical analysis of the experimental site (2007). 213

4.1.1 Effect sowing date, cultivars and plant spacing on plant 39

height (cm) of cotton crop.

4.1.2 Effect sowing date, cultivars and plant spacing on nodes per 41
plant of cotton crop.

4.1.3 Effect sowing date, cultivars and plant spacing on inter-nodal 42

distance (cm) of cotton crop.

4.1.4 Effect sowing date, cultivars and plant spacing on square 43

initiations (days) of cotton crop.

4.1.5 Effect sowing date, cultivars and plant spacing on flower 45

initiations (days) of cotton crop.

4.1.6 Effect sowing date, cultivars and plant spacing on boll split 47
initiations (days) of cotton crop.

4.1.7 Effect sowing date, cultivars and plant spacing on numbers of 50

bolls m-2 of cotton crop.

4.1.8 Effect sowing date, cultivars and plant spacing on boll weight 52
(g) of cotton crop.

vi
TABLE DESCRIPTION PAGE

4.1.9 Effect sowing date, cultivars and plant spacing on seed 54

cotton yield (kg ha-1) of cotton crop.

4.1.10 Effect sowing date, cultivars and plant spacing on ginning 56

out turn (%) of cotton crop.

4.1.11 Effect sowing date, cultivars and plant spacing on seed 57

index (g) of cotton crop.

4.1.12 Effect sowing date, cultivars and plant spacing on fruiting 58

point m-2of cotton crop.

4.1.13 Effect sowing date, cultivars and plant spacing on intact 62

fruits m-2 of cotton crop.

4.1.14 Effect sowing date, cultivars and plant spacing on shedding 63

(%age) of cotton crop.

4.1.15 Effect sowing date, cultivars and plant spacing on vegetative 65

dry matter (g m-2) of cotton crop.

4.1.16 Effect sowing date, cultivars and plant spacing on 67

reproductive dry matter (g m-2) of cotton crop.

4.1.17 Effect of sowing date, cultivars and plant spacing on 68

reproductive-vegetative ratio of cotton crop.

4.1.18 Effect of sowing date, cultivars and plant spacing on plant 70

dry matter (g m-2) of cotton crop

4.1.19 Effect of sowing date, cultivars and plant spacing on staple 73

length (mm) of cotton crop

4.1.20 Effect of sowing date, cultivars and plant spacing on 74

micronaire (ug inch-1) of cotton crop

4.1.21 Effect of sowing date, cultivars and plant spacing on fiber 75

strength (tppsi) of cotton crop

vii
TABLE DESCRIPTION PAGE

4.1.22 Effect of sowing date, cultivars and plant spacing on 76

maturity ratio of cotton crop

4.1.23 Effect of sowing date, cultivars and plant spacing on 77

brightness (Rd) of cotton crop

4.1.24 Effect of sowing date, cultivars and plant spacing on 79

yellowness (+b) of cotton crop

4.2.1 Effect of cultivars sown on May 10, plant spacing and 86

nitrogen fertilizer on plant height (cm)

4.2.2 Effect of cultivars sown on June 01, plant spacing and 87

nitrogen fertilizer on plant height (cm)

4.2.3 Effect of cultivars sown on May 10, plant spacing and 89

nitrogen fertilizer on nodes per plant

4.2.4 Effect of cultivars sown on June 01, plant spacing and 90

nitrogen fertilizer on nodes per plant

4.2.5 Effect of cultivars sown on May 10, plant spacing and 92

nitrogen fertilizer on inter-nodal distance (cm)

4.2.6 Effect of cultivars sown on June 01, plant spacing and 93

nitrogen fertilizer on inter-nodal distance (cm)

4.2.7 Effect of cultivars, plant spacing and nitrogen fertilizer at 95

different sowing date on square initiation (days)

4.2.8 Effect of cultivars, plant spacing and nitrogen fertilizer at 96

different sowing date on flower initiation (days)

4.2.9 Effect of cultivars, plant spacing and nitrogen fertilizer at 98

different sowing date on boll spilt initiation (days)

viii
TABLE DESCRIPTION PAGE

4.2.10 Effect of cultivars, plant spacing and nitrogen fertilizer at 100

different sowing date on bolls per m-2

4.2.11 Effect of cultivars, plant spacing and nitrogen fertilizer at 104

different sowing date on boll weight (g).

4.2.12 Effect of cultivars, plant spacing and nitrogen fertilizer at 106

different sowing date on seed cotton yield (kg ha-1)

4.2.13 Effect of cultivars, plant spacing and nitrogen fertilizer at 109

different sowing date on ginning out turn percentage

4.2.14 Effect of cultivars, plant spacing and nitrogen fertilizer at 110

different sowing date on seed index (g)

4.2.15 Effect of cultivars sown on May 10, plant spacing and 112
nitrogen fertilizer on total fruiting points m-2

4.2.16 Effect of cultivars sown on June 01, plant spacing and 113
nitrogen fertilizer on total fruiting points m-2

4.2.17 Effect of cultivars sown on May 10, plant spacing and 115
nitrogen fertilizer on intact fruits m-2

4.2.18 Effect of cultivars sown on June 01, plant spacing and 116
nitrogen fertilizer on intact fruit m-2

4.2.19 Effect of cultivars sown on May 10, plant spacing and 121
nitrogen fertilizer on shedding percentage

4.2.20 Effect of cultivars sown on June 01, plant spacing and 122
nitrogen fertilizer on shedding percentage

4.2.21 Effect cultivars sown on May 10, plant spacing and nitrogen 124
fertilizer on vegetative dry matter m-2.

4.2.22 Effect cultivars sown on June 01, plant spacing and nitrogen 125
fertilizer on vegetative dry matter g m-2.

ix
TABLE DESCRIPTION PAGE

4.2.23 Effect of cultivars sown on May 10, plant spacing and 127
nitrogen fertilizer on reproductive dry matter g m-2.

4.2.24 Effect of cultivars sown on June 01, plant spacing and 128
nitrogen fertilizer on reproductive dry matter g m-2.

4.2.25 Effect of cultivars sown on May 10, plant spacing and 130
nitrogen fertilizer on reproductive vegetative ratio

4.2.26 Effect of cultivars sown on June 01, plant spacing and 131
nitrogen fertilizer on reproductive vegetative ratio

4.2.27 Effect of cultivars sown on May 10, plant spacing and 133
nitrogen fertilizer on plants dry matter g m-2

4.2.28 Effect of cultivars sown on June 01, plant spacing and 135
nitrogen fertilizer on plants dry matter g m-2.

4.2.29 Effect of cultivars, plant spacing and nitrogen fertilizer at 142

different sowing date on staple length (mm).

4.2.30 Effect of cultivars, plant spacing and nitrogen fertilizer at 144

different sowing date on uniformity index (%age)

4.2.31 Effect of cultivars, plant spacing and nitrogen fertilizer at 145

different sowing date on micronaire (ug inch-1).

4.2.32 Effect of cultivars, plant spacing and nitrogen fertilizer at 147

different sowing date on fiber strength (tppsi).

4.2.33 Effect of cultivars, plant spacing and nitrogen fertilizer at 148

different sowing date on fiber elongation (%age).

4.2.34 Effect of cultivars, plant spacing and nitrogen fertilizer at 151

different sowing date on maturity ratio

4.2.35 Effect of cultivars, plant spacing and nitrogen fertilizer at 152

different sowing date on brightness (Rd)

x
TABLE DESCRIPTION PAGE

4.2.36 Effect of cultivars, plant spacing and nitrogen fertilizer at 155

different sowing date on yellowness (+b)

4.2.37 Effect of cultivars sown on May 10, Plant spacing and 158
nitrogen fertilizer on crop growth rate (g m-2 day-1).

4.2.38 Effect of cultivars sown on June 01, Plant spacing and 159
nitrogen fertilizer on crop growth rate (g m-2 day-1).

4.2.39 Effect of cultivars sown on May 10, plant spacing and 167
nitrogen fertilizer on relative growth rate (g g-1 day-1).

4.2.40 Effect of cultivars sown on June 01, plant spacing and 168
nitrogen fertilizer on relative growth rate (g g-1 day-1).

4.3.1 Effect of nitrogen fertilizer and plant spacing on plant height 176
(cm)

4.3.2 Effect of nitrogen fertilizer and plant spacing on nodes per 177
plant.

4.3.3 Effect of nitrogen fertilizer and plant spacing on inter-nodal 178

distance.

4.3.4 Effect of nitrogen fertilizer and plant spacing on square 179

initiation (days).

4.3.5 Effect of nitrogen fertilizer and plant spacing on flower 180

initiation (days).

4.3.6 Effect of nitrogen fertilizer and plant spacing on boll split 181
initiation(days).

4.3.7 Effect of nitrogen fertilizer and plant spacing on boll m-2. 182

4.3.8 Effect of nitrogen fertilizer and plant spacing on boll weight 183
(g).

xi
TABLE DESCRIPTION PAGE

4.3.9 Effect of nitrogen fertilizer and plant spacing on seed cotton 184
yield (kg ha-1).

4.3.10 Effect of nitrogen fertilizer and plant spacing on ginning out 185
turn percentage.

4.3.11 Effect of nitrogen fertilizer and plant spacing on seed index 186
(g).

4.3.12 Effect of nitrogen fertilizer and plant spacing on total fruiting 187
points m-2.

4.3.13 Effect of nitrogen fertilizer and plant spacing on total intact 188
fruits m-2.

4.3.14 Effect of nitrogen fertilizer and plant spacing on shedding 190

percentage.

4.3.15 Effect of nitrogen fertilizer and plant spacing on vegetative 191

dry matter g m-2.

4.3.16 Effect of nitrogen fertilizer and plant spacing on 193

reproductive dry matter g m-2.

4.3.17 Effect of nitrogen fertilizer and plant spacing on 195

reproductive-vegetative ratio.

4.3.18 Effect of nitrogen fertilizer and plant spacing on plant dry 197
matter g m-2.

4.3.19 Effect of nitrogen fertilizer and plant spacing on staple 199

length (mm).

4.3.20 Effect of nitrogen fertilizer and plant spacing on micronaire 200

ratio value (ug inch-1).

xii
TABLE DESCRIPTION PAGE

4.3.21 Effect of nitrogen fertilizer and plant spacing on uniformity 201

index (%age).

4.3.22 Effect of nitrogen fertilizer and plant spacing on fiber 202

strength (tppsi).

4.3.23 Effect of nitrogen fertilizer and plant spacing on fiber 203

elongation (%age).

4.3.24 Effect of nitrogen fertilizer and plant spacing on maturity 204

ratio.

4.3.25 Effect of nitrogen fertilizer and plant spacing on brightness 205

(Rd).

4.3.26 Effect of nitrogen fertilizer and plant spacing on yellowness 206

(+b).

4.3.27 Effect of nitrogen fertilizer and plant spacing on crop growth 207
crate (g m-2 day-1).

4.3.28 Effect of nitrogen fertilizer and plant spacing on relative 208

growth rate (g g-1 day-1).

4.4.1 Plant height (cm) and nodes per plant of cultivars as affected 214
by nitrogen fertilizer.

4.4.2 Inter-nodal distance (cm) and number of bolls m-2 of 216

cultivars as affected by nitrogen fertilizer.

4.4.3 Boll weight and seed cotton yield of cultivars as affected by 217
nitrogen fertilizer.

xiii
 LIST OF FIGURES
FIGURE DESCRIPTION PAGE

1 Crop Growth Rate as affected by different nitrogen 221

levels.
2 Seed cotton yield (kg ha-1) as affected by different 221
nitrogen levels
3 Seed cotton yield (kg ha-1) as affected by different plant 221
spacing.
4.1.1 Interactive effect of cultivar and sowing date at 40
maturity on plant height (cm).
4.1.2 Interactive effects of sowing dates and plant spacing on 46
flower initiation (days).
4.1. 3 Interactive effects of cultivars, sowing dates and plant 48
spacing on boll split initiation (days).
4.1.4 Interactive effects of cultivars and sowing dates on boll 49
split initiation (days).
4.1.5 Interactive effects of cultivar and plant spacing on bolls 51
m-2
4.1.6 Interactive effects of cultivar and plant spacing on seed 55
-1
cotton (kg ha )
4.1.7 Interactive effects of cultivars and plant spacing on 59
total fruiting points m-2.
4.1.8 Interactive effects of cultivars, plant spacing and 60
sowing dates on total fruiting points m-2.
4.1.9 Interactive effects of sowing dates and plant spacing on 61
total fruiting points m-2
4.1.10 Interactive effects of cultivars and sowing dates on 69
reproductive-vegetative ratio.
4.1.11 Interactive effects of sowing dates and plant spacing on 71
plant dry matter g m-2 of cultivars.

xiv
FIGURE DESCRIPTION PAGE

4.2.1 Interactive effect of spacing and cultivars on bolls m-2 101

(May-10).
4.2.2 Interactive effect of nitrogen and spacing on bolls m-2 101
(May-10).
4.2.3 Interactive effect of spacing and nitrogen on bolls m-2. 102
(June-01).
4.2.4 Interactive effect of spacing and cultivars on bolls m-2 102
(June-01).
4.2.5 Interactive effect of spacing and cultivars on seed 107
cotton yield kg ha-1 (May-10).
4.2.6 Interactive effect of nitrogen and spacing on seed 107
-1
cotton yield kg ha (June-01).
4.2.7 Interactive effect of nitrogen and plant spacing on total 114
fruiting points m-2 at 100 DAS (May-10).
4.2.8 Interactive effect of nitrogen and plant spacing on 117
intact fruits m-2 at 100 DAS (May-10).
4.2.9 Interactive effect of nitrogen and spacing on intact 117
-2
fruits m at 150 DAS. (May-10).
4.2.10 Interactive effect of cultivars and plant spacing on 118
-2
intact fruits m at 150 DAS (May-10).
4.2.11 Interactive effect of nitrogen and cultivars on intact 118
fruits m-2 at 100 DAS (June-01).
4.2.12 Interactive effect of nitrogen and plant spacing on 119
intact fruits at m-2 100 DAS (June-01).
4.2.13 Interactive effect of nitrogen and plant spacing on 119
-2
intact fruits m at 150 DAS (June-01).
4.2.14 Interactive effect of cultivars and plant spacing on 129
-2
reproductive dry matter g m at 100 DAS (May-10).
4.2.15 Interactive effect of nitrogen and cultivars on total plant 134
dry matter g m-2 at 100 DAS (May-10).

xv
FIGURE DESCRIPTION PAGE

4.2.16 Interactive effect of cultivars and plant spacing on total 136

plant dry matter g m-2 at 100 DAS (May-10).
4.2.17 Interactive effect of nitrogen and plant spacing on total 136
-2
plant dry matter g m at 150 DAS (May-10).
4.2.18 Interactive effect of nitrogen, plant spacing and 137
-2
cultivars on total plant dry matter g m at 100 DAS
(May-10).
4.2.19 Interactive effect of cultivars and plant spacing on total 138
plant dry matter g m-2 at 150 DAS (May-10).
4.2.20 Interactive effect of nitrogen and plant spacing on total 138
plant dry matter g m-2 at 100 DAS (June-01).
4.2.21 Interactive effect of cultivar and plant spacing on total 139
-2
plant dry matter g m at 100 DAS (June-01).
4.2.22 Interactive effect of nitrogen and cultivars on total plant 139
dry matter g m-2 at 150 DAS (June-01).
4.2.23 Interactive effect of nitrogen, plant spacing and 140
cultivars on total plant dry matter g m-2 at 100 DAS
(June-01).
4.2.24 Interactive effect of nitrogen and plant spacing on total 141
-2
plant dry matter g m at 150 DAS (June-01).
4.2.25 Interactive effect of cultivar and plant spacing on total 141
-2
plant dry matter g m at 150 DAS (June-01).
4.2.26 Interactive effect of nitrogen, spacing and cultivars on 149
fiber elongation (%age).
4.2.27 Interactive effect of nitrogen, spacing and cultivars on 153
brightness (Rd).
4.2.28 Interactive effect of spacing and cultivars on 156
yellowness (+b).
4.2.29 Interactive effect of nitrogen and plant spacing on crop 160
growth rate g m-2 day-1 at 50 DAS (May-10).
4.2.30 Interactive effect of plant spacing and cultivars on crop 160
growth rate g m-2 day-1 at 100 DAS (June-01).

xvi
FIGURE DESCRIPTION PAGE

4.2.31 Interactive effect of nitrogen and cultivars on crop 161

growth rate g m-2 day-1 at 150 DAS (June-01).
4.2.32 Interactive effect of nitrogen and plant spacing on crop 161
-2 -1
growth rate g m day at 150 DAS (June-01).
4.2.33 Interactive effect of nitrogen, plant spacing and 162
-2 -1
cultivars on crop growth rate g m day at 100 DAS
(May-10).
4.2.34 Interactive effect of nitrogen, plant spacing and 163
cultivars on crop growth rate g m-2 day-1 at 150 DAS
(May-10).
4.2.35 Interactive effect of nitrogen, plant spacing and 164
-2 -1
cultivars on crop growth rate g m day at 100 DAS
(June-01).
4.2.36 Interactive effect of nitrogen, plant spacing and 165
cultivars on crop growth rate g m-2 day-1 at 150 DAS
(June-01).
4.2.37 Interactive effect of plant spacing and cultivars on crop 166
growth rate g m-2 day-1 at 150 DAS (June-01).
4.2.38 Interactive effect of nitrogen and plant spacing on 169
-1 -1
relative growth rate g g day at 150 DAS (May-10).
4.2.39 Interactive effect of nitrogen and plant spacing on 169
-1 -1
relative growth rate g g day at 150 DAS (June-01).
4.3.1 Interactive effect of nitrogen and plant spacing on 188
intact fruits m-2 at 100 DAS.
4.3.2 Interactive effect of nitrogen ad plant spacing on 190
shedding percentage at 100 DAS.
4.3.3 Interactive effect of nitrogen and plant spacing on 192
-2
vegetative dry matter g m at 150 DAS
4.3.4 Interactive effect of nitrogen ad plant spacing on 194
reproductive dry matter g m-2 at 150 DAS.
4.3.5 Interactive effect of nitrogen ad plant spacing on 196
reproductive-vegetative ratio at 100 DAS.

xvii
4.3.6 Interactive effect of nitrogen ad plant spacing on 196
reproductive-vegetative ratio at 150 DAS.
4.3.7 Interactive effect of nitrogen ad plant spacing on plant 198
-2
dry matter g m at 150 DAS.
4.3.8 Interactive effect of plant spacing and nitrogen levels 207
-2 -1
on crop growth rate g m day at 150 DAS.
4.3.9 Interactive effect of plant spacing and nitrogen levels 208
on relative growth rate g g-1 day-1 at 150 DAS.

xviii
 LIST OF APPENDICES
Appendix DESCRIPTION PAGE

I Meteorological data recorded at Central Cotton 241

Research Institute, Multan during the year 2004
II Meteorological data recorded at Central Cotton 241
Research Institute, Multan during the year 2005
III Meteorological data recorded at Central Cotton 242
Research Institute, Multan during the year 2006
IV Meteorological data recorded at Central Cotton 242
Research Institute, Multan during the year 2007

xix
 Abbreviations

DAS Days after sowing

H Open boll

ha Hactare

i.e for example

LDW Leaf dry weight

LSD Least significant difference

N Nitrogen

RDW Reproductive dry weight

RVR Reproductive Vegetative Ratio

SDW Stem dry weight

VDW Vegetative dry weight

X Shed bud or boll

D Sowing date

C Cultivar

S Plant Spacings

CGR Crop growth rate

RGR Relative growth rate

GOT Ginning out turn

EC Electric conductivity

LSD Least significant difference

xx
 INTRODUCTION

Cotton is a leading world wide fiber and cash crop that is grown commercially for

agricultural and industrial purposes in the temperate and tropical regions of more than

fifty countries (Smith, 1999). Although cotton is mainly grown for fiber purpose but it

has many valuable uses as its seed comprises of 30% starch, 25% crude oil and 16.2%

protein (Cobley and Steel, 1976). It plays a significant role in the country’s economy

because of its high quality fiber. Pakistan is the fourth largest producer of cotton, the

second largest exporter of raw cotton and the third largest consumer of cotton in the

world. Cotton is grown on an area of 2.63 million hectares in Pakistan with an overall

seed cotton production of 10.98 million bales. Cotton accounts for 6.9 percent of the

value added in agriculture, 40% in employment, 60% in foreign exchange earning, 64%

source of edible oil and about 1.4 percent to GDP (Govt. of Pakistan, 2010) Additionally

cotton provides raw materials to the local industries comprising of 396 textile mills, 960

ginning factories, 9.7 million spindles and over 2622 oil expelling units (Anonymous,

2011).

Cotton crop is very sensitive to environmental conditions and grown in a wide range of

ecological zones. A number of factors such as nature of cultivars, plant density, sowing

time, nutrients and water management practices are involved in getting a profitable yield

(Ali, et al., 2005).

The potential of a cultivar is mainly associated with appropriate sowing time, nutrient

management, protection measures and plant density that directly affect the soil moisture

extraction, light interception, humidity and wind movement. Therefore, cultivar selection

is a key component in any cropping system, and even more critical in specific plant

spacing and sowing date for cotton production. A better crop growth is ensured by the

1
appropriate coordination of different agronomic practices and judicious use of various

inputs and among these, planting date is very important to explore the potential of a

cultivar in the region.

Sindh 29% NWFP &

Balochistan: 1%

Punjab 70%

Late planting usually results in reduced yield and fiber properties due to a shortened

fruiting period and delayed maturity relative to normal planting (Bange, et al., 2008;

Bange, et al., 2004).

The important agronomic consideration for growers is to ensure optimum yield and

quality of the crop. The agronomists have developed new cultivation practices adapted to

late planting with the aim of accelerating the crop cycle while reducing the vegetative

vigor. Thus, optimum sowing time for a cultivar in a region is also considered to be an

important manageable factor in cotton crop (Bozbek, et al., 2006). Cultivars differ in

their architecture which determines the optimum spacing required for a cultivar for

2
profitable yield. The narrow row spacing increases total seasonal light interception that

potentially increase cotton yield (Steglich, et al., 2000; Heitholt, et al., 1992).

Nitrogen is one of the major essential nutrients for plant growth and development it is

widely recognized that nitrogen supply exerts a remarkable effect on vegetative and

reproductive growth and thus, excessive nitrogen, especially in combination with high

late-season moisture availability, can delay maturity, reduce harvesting, ginning

percentages, promote boll shedding, diseases, and insect damage. However, low nitrogen

fertility is associated with slower growth and smaller leaves, greater root shoot ratio,

increased earliness and greater shedding percentage (Radin and Mauney, 1986). Thus, an

adequate supply of nitrogen is associated with high photosynthetic activities, vigorous

vegetative growth and a dark green color. Therefore, keeping in view the importance of

these agronomic considerations, the present study was planned with the following

objectives;

 To determine the performance of morphologically different cultivars in an arid

sub-tropical climate

 To determine the appropriate plant spacing and best sowing time for specific

cultivars in a region

 To evaluate the yield potential of cotton cultivars under various levels of nitrogen

and plant densities

 To find out the partitioning of dry matter production under various levels of

nitrogen fertilizer

3
 REVIEW OF LITERATURE

2.1 Cotton Cultivars and Sowing Time

Cotton (Gossypium hirsutum L.) is the leading world wide fiber crop that is grown

commercially in the temperate and tropical region of more than fifty countries (Smith,

1999). The most important agronomic consideration for a grower is to ensure optimum

yield and quality of the crop. Since, cotton is considered to be a responsive crop to its

surrounding environments therefore, an appropriate sowing time is very important to

realize its optimum yield potential. The cotton cultivars differ in their growth

characteristics such as height, fruit development, drought tolerance, maturity, earliness,

yield potential and many fiber properties (Niles and Feaster, 1984). The potential of a

cultivar is mainly associated with appropriate sowing time, nutrient management,

protection measures and plant density that directly affect the soil moisture extraction,

light interception, humidity and wind movement (Ali et al., 2005). However, the

selection of an appropriate sowing time in a particular region can be difficult and is a

decision that must strike a balance between sowing too early; enduring problems

associated with low temperature and too late; loosing potential yield.

Development of a cotton crop is a full-season process involving a complex, balance

between vegetative and reproductive allocations. The increased reproductive and

vegetative ratio indicates better mobilization and utilization of photosynthates to towards

developing bolls that will result higher seed cotton yield with better fiber quality. Two

years field studies on cotton crop were conducted at the Texas Cooperative Agricultural

Research and Extension Center, USA during 1997 and 1999 to compare the effect of boll

position, flowering dates and environmental factors on the fiber properties. Cotton

cultivar (Deltapine-5409) was sown on March 01 (early), March 22, 24 (middle) and

4
April 11, 12 (late) during both years. They reported that early planting produced

significantly higher lint yield (731 kg ha-1) than the middle (622 kg ha-1) and late (533 kg

ha-1) planting dates. Furthermore, early planting caused an increase in fiber length and

micronaire values at all boll locations (Davidonis et al., 2004).

Similar studies regarding the effect of early planting of cotton on the lint yield and fiber

quality were conducted at Mississippi Delta during 1996 to 2000. Experiments conducted

from 1996 to 1998 involved eight cotton genotypes, two modern adapted genotypes

(MD-51 ne and SureGrow-125) and six obsolete genotypes (Auburn-56, Coker-100A,

Delta Pine-11A T 154-2, Kekchi, M8, and Patty s Toole). These cotton cultivars were

planted on April 8, 1996 and April 01, 1997 and 1998 (early) and May 02, 1996, May 01

1997 and May 04 1998 (normal) planting. The second experiment was conducted from

1999 to 2000 using four modern cotton genotypes (Delta Pine-20B, Fiber Max-832,

Paymaster-1220 BG\RR and Photogen PSC-952). The planting of the cotton was done on

April 01 (early) normal planting was done on May 01 during both the years. They

reported that early planting cotton produced the taller plants, more main stem nodes and

height node ratio than normal planting. The early sown crop produced more number of

bolls than late sown crop and contributed 10 % yield improvement over the normal

planted crop. Further, early planted cotton produced fiber with higher micronaire and

maturity percentage than normal planting (Pettigrew, 2002).

Work on planting dates for cotton has been summarized in most of the cotton growing

countries in the world and a number of researchers are agreed with that late planting

usually resulted in reduce yield and poor fiber qualities due to a shortened fruiting period

and delayed maturity relatively to normal planting (Bange et al., 2004 and Bauer et al.,

2000). Similarly, at Agriculture Research Station, Rajasthan, India, Poonia et al., (2002)

conducted experiments during 1996-98 with four cotton genotypes (Bikaneri Nerma,

5
RST-9, Gainganager Ageti and F-505) planted on April 05 and 20. They reported that

every fortnight delay in planting beyond 20 April that resulted a significant decrease in

yield. The sowing date studies were also conducted by Bauer et al. (1998) during 1991 to

1993 at Horns Ville with three cotton genotypes (PD-5286, PD-5358 and PD-5472)

planted during late April and late May. They observed that cotton planted during late

May gave higher fiber length and strength but lower micronaire and fiber maturity than

cotton planted during late April. The effect of planting date on fiber properties of bolls at

two flowering times and the relationship between the fiber properties and canopy

photosynthesis during the development of bolls was also studied at Clemson University’s

Pee Dee Research and Education Centre near Florence, SC, USA during 1995 and 1996.

Cotton cv. Stoneville-453 planted on May 03 (normal sowing) during the both years and

June 03 during 1995 and May 31, 1996 (late sowing) showed that the average maximum

canopy photosynthesis, within each year did not differ with planting dates however,

approximately 30% less yield was recorded with late planting during each year (Bauer et

al., 2000).

On the other side, delayed sowing produced more vegetative dry matter and fiber with

higher value of yellowness that is considered undesirable quality of fiber by the textile

industry and increased fruit shedding percentage that resulted lower seed cotton yield at

final harvest. A field study was conducted at Cotton Research Station, Multan Pakistan

during 1998 and 1999 to determine the proper planting time of two cultivars; MNH-552

and MNH-554. The cultivars were sown on April 01, 15, May 01, 15, June 01, 15, July

01 and 15. Irrespective of the cultivars, May 15 produced significantly the highest

average boll number (37.5), boll weight (3.17g) and seed cotton yield of 3513 kg ha-1

whereas the lowest yield of 238 kg ha-1 was obtained in late sowing crop on July 15.

MNH-552 produced higher number of bolls and seed cotton yield as compared to MNH-

6
554. However, both the cultivars significantly reduced the yield in late sowing dates and

produced a similar trend during both the years (Hassan et al., 2003).

Similarly, Anwar et al. (2003) made another investigation at the Central Cotton Research

Institute, Multan, Pakistan during 1999 to 2001 to find the appropriate sowing time of

cotton and planted cultivar CIM-446 on May 01, June 01 and July 01. They observed that

early sowing on May 01 and June 01 produced significantly higher seed cotton yield and

more number of bolls than late sown crop on July 01. Some other investigators also gave

importance to sowing time to harvest a profitable final yield. Thus, in Turkey during

2000 and 2001 a standard cotton cultivar Cukurova-1518 was planted on May 10, 17 and

24 during both the years. They reported that the early sown crop on May 10 produced the

maximum number and the highest weight of opened bolls which ultimately led to

increase the seed cotton and lint yield that were 26.9 and 24.3 % higher respectively than

the crop sown late on May 24. Further, they found that early planting produced taller

plants, more height-node ratio and higher fiber strength and equal in micronaire than that

from the late sowing crops of the region (Gormus and Yucel, 2002).

The impact of sowing time (April 10, May 10 and June 10) with three cotton genotypes,

Rehmani, NIAB-78 and Qalandri was studied at Latif Experimental Farm, Sindh

Agriculture University, Tandojam during 1999 and 2000 (Oad et al., 2002). They

reported that the sowing on May 10 produced higher seed index (8.21 g), the maximum

lint index of 4.04 g and higher ginning out turn percentage of 33.98 than crop sown on

April 10 and June 10. Cultivar Rehmani produced higher seed index (8.48 g), lint index

(4.033 g) and ginning out turn percentage (33.71) than other cultivars. Similarly, Hassan

et al. (2005) studied the impact of sowing dates (May 01, 15, June 01, 15 and July 01)

with three cotton cultivars (MNH-700, MNH-768 and FH-900) on the seed cotton yield

and its components at Cotton Research Station, Multan during 2003 and 2004.

7
They observed that sowing on May 15 produced the highest seed cotton yield of 3530 kg

ha-1 and the lowest seed cotton yield of 864 kg ha-1 was recorded on July 01. Comparison

among the cultivars showed that MNH-700 and MNH-768 produced higher seed cotton

yield of 2528 and 2408 kg ha-1 respectively as compared to FH-900 which produced 2315

kg ha-1 seed cotton yield.

The response of cotton cultivars CIM-473 and CIM-482 on planting dates (May 10, June

01 and June 20) in relation to seed cotton yield was observed at Central Cotton Research

Institute, Multan during 2004 (Ali et al., 2005). They reported that number of bolls m-2

and seed cotton yield of both the cultivars decreased significantly with delay in crop

sowing. Crop sown during the month of May produced 8 % more seed cotton yield than

June 01 whereas, crop sown on June 01 gave 40% more yield than the crop sown late on

June 20. However, boll weight increased as the sowing was delayed while boll number

was higher in early sown crop. Further, cultivars CIM-473 produced significantly higher

seed cotton yield than CIM-482.

Some studies about the impact of sowing dates i.e. September 27 (early), October 24

(normal) and November 27 (late) with three cotton cultivars (Sicala S-40i, Siokra V-16i

and Pima S-7) were conducted at Australian Cotton Cooperative Research Centre in

Hillston during 2002 and 2003. They reported that both the early and late sowing dates

reduced yield which is associated with a lower boll number and smaller size in early

sowing date and poor ginning out turn in the late sowing. However, normal sowing date

produced the maximum lint yield as normal sowing allowed the crop to promote early

vigor and maximize season length which develops bolls and fiber properly that resulted

in higher production. Cultivar Sicala S-40i gave the highest lint percentage, more boll

size and higher micronaire than other cultivars (Bange et al., 2004).

8
Experiments were also conducted at Agronomic Research Station, Bahawalpur during

1999 and 2000 to evaluate the optimum sowing time of six cotton cultivars (SLS-1, BH-

118, NIAB-Karishma, FVH-53, CIM-443 and CIM-448) planted on May 01, 16, June 01

and 16 They reported that crop sown on May 16 produced the maximum number of bolls

per plant (40.11) and 100 boll weight (357.70 g) which ultimately resulted in the highest

seed cotton yield of 2403 kg ha-1. However, among the cultivars NIAB-Karishma

produced significantly higher seed cotton yield of 2219 kg ha-1 than other cultivars. Thus,

cotton sown earlier or later than its optimum time showed a rapid decline in its yield

(Akhter et al., 2002).

Arshad, et al. (2007) conducted an experiment at the experimental area of PARS,

University of Agriculture, Faisalabad during 2005 to study the effect of sowing dates i.e.

May 20 and June 10 of four cotton cultivars CIM-496, CIM-506, NIAB-111 and SLH-

284. They found crop sown early on May 20 produced 10 % more flowers, 23% more

open bolls, 18% more seed cotton yield and 13 % more ginning outturn than crop sown

late on June 10. Cotton cultivar SLH-284 produced the highest seed cotton yield of

1462.8 kg ha-1.

Early canopy development is important in establishing a structure that can effectively

support growth in the reproductive period. Therefore, Bange et al. (2008) conducted

experiments at the Australian Cotton Research Institute (ACRI) Narrabi during 2002-04

with different sowing dates in each year i.e. 2002 (September 24, October 15 and

November 11), 2003 (October 13, November 5 and 28) and 2004 (October 06, 22 and

November 04) for managing yields of high fruit retention in transgenic cotton and two

cotton cultivars Sicot-189 (non-Bollguard II) and Sicot-289B (Bollguard II). They

reported that delay in sowing, lint %age, boll number m-2, were decreased which resulted

a decrease lint yield. It was also observed that micronaire was also decreased with delay

9
in sowing while fiber length was increased. However, cultivar Bollguard II (Sicot-289B)

produced more boll number, lint yield, fiber length and micronaire than non Bollguard II

(Sicot-189) which maintained its yield through the shorter fruiting cycle, allowing time to

support growth and development.

2.2 Cotton Cultivars and Plant Density

Plant density directly influences the soil moisture extraction, light interception, humidity

and wind movement (Heitholt et al., 1992). These factors in turn influence the plant

height, branch development, fruit location and size, crop maturity and ultimately yield.

Two general plant density patterns i.e. low and high have been followed for planting

cotton. The benefits of each have been realized in different experiments carried out in

various regions of the worlds. The researchers have found the benefits of high density

and reported that high density plant stand results in less erosion, less weed pressure and

early maturity of cotton crop. The experiment conducted in North California environment

revealed that there is a potential for higher yield and quality of cotton in case of dense

stand (Guthrie, 1991).

Heitholt et al. (1992) evaluated the effects of a combination of row spacing with different

genotypes on yield of upland cotton planted near Stoneville, MS, during 1989 and 1990.

An Okra leaf genotype and a normal leaf iso-line were grown in the field using 0.5m

(narrow) and 1.0m (wide) row spacing in early and late planting during both the years.

They reported that narrow row spacing increased seasonal isolation interception in both

leaf types. Narrow rows increased the yield of the Okra leaf over that of wide rows in

both the years. The yield increase of the Okra leaf grown in narrow rows was resulted

with an increase in number of mature fruits produced per unit area but not an increase in

fruit size. The use of narrow row culture of the Okra leaf type provides an opportunity to

overcome its low leaf area, increase in insulation interception and lint yield.

10
The importance of ultra narrow row sowing technique in cotton is to minimize production

cost and increase in fertilizer and water use efficiency. Therefore, keeping in view the

importance of narrow spacing, Nichols et al. (2004) studied the performance of modern

cotton cultivars in ultra-narrow rows for cotton production at Mississippi Delta during

1998-2000. Six cultivars (ST BXN-47, FM-832, NuCotn-35B, PM-1220 RR, SG-125 BR

and ST-474) were sown with three row spacing of 25, 38 and 101 cm. They reported that

plant height, number of sympodia, total number of nodes and bolls per plant decreased in

cotton grown in ultra-narrow row spacing but ultra-narrow row spacing produced more

seed cotton yield and lint percentage relative to broad spacing. This was attributed

because of higher boll percentage and number of plants. Further, it was reported that

narrow row spacing has led lower fiber uniformity compared to broad spacing.

The field studies have proved that main stem nodes, number of fruits per plant and

overall fruit retention increased with low plant density. Similar studies were conducted

by Bednarz et al. (2000) at Coastal Plain Experimental Station, University of Georgia

with the objective to find out the components of final lint yield impart the yield stability

across plant population and population density influence the yield distribution during

1997-98. Cotton cultivar Suregrow-501 was planted at 91cm row spacing with different

seed rates 3.5, 7.2, 10.8, 14.3 and 21.5 seeds m-2. They reported that low plant population

densities produced more main stem nodes, plant height, monopodial branches and boll

number that resulted in more fruit retention, fruit production per plant.

Similarly, Jones and wells (1998) investigated that lint yield and quality of cotton grown

at two divergent population densities at Central Crops Research Station in Clayton, NC.

Cotton cultivar Deltapine-5690 was sown on May 13, 1992 and May 04, 1993 and

reported that plant population didn’t affect lint yield, however due to favorable late

season weather, two plants m-2 gave more bolls at different sympodial positions than

11
grown at twelve plants m-2. They also found that boll weight and micronaire values were

greater for earlier produced bolls at all positions in lower plant population.

Galadima et al. (2003) made a field study at the University of Arizona Maricopa

Agricultural Center to determine the relationships of plant population with conventional

row spacing under a range of high population conditions with new Upland cotton

(Gossypium hirsutum L.). The cotton cultivars AG-3601, DP-458BR, and STV-4892BR,

were grown with six plant populations of 15000, 30000, 45000, 60000, 75000, and 90000

plants ha-1. They reported that cultivars showed significant differences in lint yield and

fiber strength but not the fiber micronaire however; higher population did not affect

significantly the lint yield, fiber quality and fiber micronaire to premium levels as well.

It is observed that benefits of plant population are dependent on the response of

morphological and phenological traits of the plant. Therefore, Heitholt (1995) conducted

a field experiment on the impact of cotton flowering and boll retention with different

planting configuration and leaf shapes at Mid South and South East, USA during 1991

and 1992. Normal and Okra leaf Iso-lines of cotton variety DES-24-8 were planted with

51 and 76 cm narrow rows and 102 cm wide rows having plant density of 5, 10, 15 and

20 plants m-2 in 1991 and 2, 3,5,10 and 15 plants m -2

in 1992. Row spacing of 51 cm

increased number of flowers by 12% and yield by 4% against spacing of 102 cm. Results

also concluded that plant density and number of main stem nodes had little effect on

flower number or boll retention. Further, higher plant density tended to reduce number of

main stem nodes plant-1. Boll retention for normal leaf was higher than okra leaf. They

also observed that increased flower production in narrow row spacing which ultimately

increased seed cotton yield.

12
Growth and yield comparisons of cotton planted in conventional and ultra-narrow row

spacing were also studied during 1997-98 by Jost and Cothren (2000). They used four

row spacing of 19.0, 38.1, 76.2 and 101.6cm with different plant populations of 39.4 to

45.8, 18.2 to 20.7, 13.1 to 13.6 and 7.9 to 9.9 plants m-2 respectively at Brazos Bottoms,

near College Station, TX. Plant height and nodes number were reduced in the cotton

grown with 19cm row spacing at crop maturity. Closed canopy occurred with 19 and 38.1

cm row spacing than with the wider row spacing. However, during 1997, yields were not

affected by the row spacing treatments because of wet growing season while dry growing

season was prevalent during 1998, therefore, narrow row spacing produced higher seed

cotton yield with 19 and 38.1 cm row spacing than wider row spacing. The narrow row

spacing (19 cm) had 84.6% and 76.1% harvestable bolls at the first and 6 to 10 fruiting

positions respectively, and both percentages were significantly higher than wider row

spacing. However, 19 cm spacing reduced the fiber length and appears to be a viable

factor for producers to reduce costs while increasing yields than wider row spacing.

Similarly, these scientists conducted another study during 1998-99 near College Station,

TX to understand the differences between phenotypic alterations and crop maturity in

ultra-narrow row and conventionally spaced cotton. Cotton crop was sown in varying soil

types with 19, 38, 76, and 101 cm row spacing. Plant densities with 19 cm rows were

12.2, 18.8, and 40.5 plants m-2 whereas plant densities of 11.3 and 19.5 plants m-2 were

established with 38 cm rows. With 76 and 101 cm rows, plant densities of 11.7 and 7.4

plants m-2, respectively, were evaluated. The narrow row spacing (19 and 38 cm)

produced more biomass of vegetative and reproductive structures, more harvestable bolls,

earlier crop maturity that resulted higher yield than conventional row spacing (76 and 101

cm) while, both plant densities did not significantly affect fiber qualities (Jost and

Cothren, 2001).

13
During 2001-02 an experiment was conducted at South west Branch Agricultural

Experimental Station, in Plains, GA and two cotton cultivars (DPL-458BR and FM-966)

were sown and hand thinning was done to maintain the required plant populations at 3.6,

9.0, 12.6 and 21.5 plants m-2. They reported that with an increase in plant density

increased the lint yield boll-1, individual seed weight and seed number boll-1 decreased

while bolls m-2 increase that resulted an increase in seed cotton yield (Bednarz et al.,

2006).

The role of plant populations and seeding configurations were studied at Dean Lee

Research Station, Alexandria during 2003-04 with the aims of specific combinations that

minimize seed use without sacrificing yield and developmental changes and identify

potential growth associated with cotton. Thus, cultivar paymaster-1218 BG/RR was

grown with different plant population of 33978, 50958, 76466 and 152833 plants ha-1 in

two seeded configuration with 96.5 cm row width. They noted the positive relationship

between plant population and plant height; however, main-stem nodes per plant and boll

retention were inversely related to plant density. 152883 plants ha-1 produced the

maximum lint yield of 1465 kg ha-1with three plants per 20 cm hill spacing while the

minimum lint yield of 1177 kg ha-1 was observed with lower plant population 50958

plants ha-1 with three plants per hill and 60 cm hill spacing. However, it is observed that

fiber properties with different treatments were not influenced significantly (Siebert et al.,

2006).

At Cotton Research Center, (Northern Shandong, China) cotton cultivar SCRC-15 was

planted at different planting densities (2.25, 3.75 and 5.25 plants m-2) during 2002-03.

Researchers reported that boll weight was significantly affected by plant density during

both the years and boll weight decreased with increase in plant density while the boll

number per unit area was increased at maximum plant density during 2002. However,

14
seed cotton yield and lint yield was slightly increased but differences were not significant

statistically with plant population in either the year (Dong et al., 2005).

Similarly, experiments were also conducted at University of Georgia Experiment Stations

to determine the effect of plant density on lint yield, fiber quality and profitability of

cotton during 2001-02. Here two cotton cultivars (DPL-458BR and FM-966) were sown

and hand thinning was done to maintain a plant density of 3.6, 9.0, 12.6 and 21.5 plants

m-2. It was reported that staple color, length and uniformity were not influenced

significantly with plant density while lint yield was increased with increasing in plant

population and boll size was inversely related to plant density. Cotton cultivars gave a

better effect on fiber characteristics and at higher plant densities fiber strength was

increased but reduced micronair value (Bednarz, 2005).

However, a field experiment was conducted at Coahuila, Mexico to study the effect of

plant population and agronomic traits of three early sown cotton cultivars (CIAN Precoz,

CIAN Precoz-2 and CIAN-95) and a late cultivar (Deltapine-5690) with four populations

of 70000, 82500, 95000 and 108000 plants ha-1 in rows 70 cm apart during 1997-98

(Palomo et al., 2000). They reported that early sown cultivars gave the highest yield than

late sown cultivar and the yield of early cotton cultivars (CIAN Precoz and CIAN Precoz-

2) was increased with increasing planting density while number of bolls per plant

decreased with an increase in plant density.

Brito et al., 2002 planted four upland cotton cultivars (CNPA-7H, BRS187-8H, BRS186-

Precoc 3 and BRS-201) with four different spacing of 1.0 x 0.125 m (A1), 0.7 x 0.178 m

(A2), 0.6 x 0.28 m (A3) and 0.5 x 0.25 m (A4) at Arapiraca, Alagoas State, Brazil during

2001. They reported that A2 and A3 arrangements produced the highest yield relative to

other arrangements and the maximum boll weight was obtained by BRS 187-8H and the

15
cultivar BRS-201 gave the highest fiber percentage while BRS 186-Precoce 3 gave the

smallest percentage of fiber and the shortest height of the first sympodial branch.

2.3 Cotton Cultivars and Nitrogen Fertilizer

The efficient use of fertilizers is a key factor in maximizing yield of a crop in such a way

that it has a minimal impact on the environment. Nitrogen is one of the most essential and

major nutrients for plant growth and yield in the world. Previous studies have revealed

that new cultivars are more responsive to nitrogen application and there are significant

interactions between cotton cultivars and nitrogen fertilizers. New cultivars produced

12% more seed cotton yield at the higher nitrogen rate of 112 kg ha-1 while the obsolete

cultivars which yielded only 8% increase at the same nitrogen rate at Stoneville

(Meredith et al. 1997).

Cotton plants require larger amount of nitrogen than any other elements and is important

for canopy area development and photosynthesis resulting in higher boll number and

yield of crop. Nodes above white flower is an important component of cotton growth and

development, as it indicates and predicts the balance between vegetative and reproductive

growth and thus, used as an indicator of crop maturity. Bondada and Oosterhuis, (2001)

conducted field experiments during 1992 and 1993 at the Cotton Branch Experiment

Station, Marianna to determine the effect of nitrogen (i.e. 0, 55, 82 and 110 kg ha-1) on

the nodes above the uppermost white flower, specific leaf weight, boll number, and dry

weight of cotton. They reported that plants in the highest soil nitrogen regime produced

the greatest crop photosynthesis, specific leaf area, boll number and boll dry weight.

It is obvious that seed cotton yield is increased with nitrogen application and this could

be attributed to the fact that nitrogen is an essential nutrient in creating the plant dry

matter, as well as energy-rich compounds which regulate photosynthesis and plant

16
production. Hassan et al., (2003) conducted field experiments at Cotton Research Station

Multan during 1998 to 2000 to determine the nitrogen use efficiency of cultivar MNH-

554 at different nitrogen levels (i.e. 0, 56, 112 and 168 kg ha-1). They concluded that the

maximum seed cotton yield was obtained with 168 kg N ha-1 rate. Similarly, Chaudhry

and Sarwar, (1999) studied the cultivar NIAB-78 with nitrogen doses of 0, 30, 60, 90,

120, 150 and 180 kg ha-1 at the Agronomic Research Area, University of Agriculture,

Faisalabad during 1995-96 and they recorded the highest monopodial, sympodial

branches, ginning out turn and seed cotton yield with 150 kg N ha-1 and further, reported

it is an optimum nitrogen dose under sandy clay loam soil along with 60 kg P2O5 ha-1.

Cotton is not only a fiber crop in the world but also having a potential source of proteins

and oil. Sawan et al. (2006) investigated nitrogen fertilizer (95.2 and 142.8 kg N ha-1), in

the form of ammonium nitrate, in two equal splits at six and eight weeks after sowing,

together with foliar application of potassium at the rate of 0, 400, 800 and 1200 ppm of

K2O and twice spray of 1,1-dimethyl-piperidinium chloride at the rate of 0, 50 after 75

days and 0, 25 ppm after 90 days of planting as plant growth retardant on cotton cultivar

Giza-86 at the Agricultural Research Center, Giza, Egypt during 1999-2000. They

reported that higher rate of nitrogen with the application of potassium and plant growth

retardant resulted in an increased cotton seed yield, seed index, oil and protein content.

However 13.03 % seed yield ha-1 increased significantly because of raising the nitrogen

rate from 95.2 to 142.8 kg ha-1.

Generally increase in yield due to nitrogen application is mainly through an increase in

the number of fruiting bolls while increase in number of bolls is happened due to increase

in the plant height which resulted in higher number of nodes that resulted in higher seed

cotton yield. A study was made to evaluate the optimum nitrogen requirement for cotton

cultivar DNH-25 at Cotton Research Station, D. I. Khan, Pakistan. Four different rates of

17
nitrogen i.e. 0, 50, 100 and 150 kg ha-1 were applied to cotton crop and found that 150 kg

N rate produced the more number of bolls with greater boll weight that resulted in the

highest seed cotton yield (Khan et al. 2005).

Fritschi et al. (2003) studied the response of irrigated Acala and Pima cotton cultivars to

nitrogen fertilizer at the rate of 56, 112, 168 and 224 kg ha-1 at San Joaquin Valley, CA

during the growing seasons of 1998, 1999 and 2000. Acala was grown for three years on

a “Panoche” clay loam and “Wasco” sandy loam while Pima was grown for two years on

“Panoche” clay loam soils. They found that on both the soil types, plant height and nodes

plant-1 in Acala cotton were increased when nitrogen was applied at the rate of 168 kg ha-
1
and they also reported a linear increase in the lint yield with increased nitrogen rates

168 kg ha-1 treatment in both the years.

Studies also indicate that judicious use of nitrogen have positive effect on seed cotton

yield because nitrogen is a yield limiting factor in any crop production system. Therefore,

most of the growers are successful in meeting yield and quality goals by adopting

judicious nitrogen management practices. Anwar et al. (2003) conducted a field

experiment at Central Cotton Research Institute, Multan during 2002 to study the

optimum fertilizer requirement of cotton crop. They used four levels of nitrogen (50, 100,

150 and 200 kg ha-1) with three cotton cultivars (i.e. CIM-499, CIM-511 and CIM-707)

and reported that 150 kg N ha-1 in silt clay loam soil gave significantly the highest yield.

Few studies have shown linear increase up to certain doses of nitrogen, after that

diminishing return was also observed for nitrogen application. McConnell et al. (1993)

determined the response of three cotton cultivars (Arkot-518, Stoneville-453 and

Deltapine-90) to nitrogen application (0, 56, 112, 168 and 224 kg ha-1) during 1989 to

1991 at the University of Arkansas Southeast Branch Experiment Station at Rower, AR.

18
The pronounced response of the cotton was reported as an effect of nitrogen application,

however, in excess of 112 kg N ha-1 did not increase the seed cotton yield significantly

throughout the study period. Further, increase in nitrogen rate reduced the earliness of

cotton crop such as the cultivars, Arkot-518 was the earliest that followed by the

Stonville-453 and then Deltapine-90.

Boquet et al. (1994) conducted experiments to evaluate the response of cotton to pre-

plant nitrogen rates of 0, 28, 56, 84,112,140 and 168 kg ha-1 with split application of

56+56 kg N ha-1 during 1987-90 at the Northeast Research Station near St. Joseph, LA.

The results showed that increasing nitrogen rates from zero to 84 kg ha-1 increased

average whole plant, individual boll weight by 0.16 g and average yield per fruiting site

by 0.29 g. The same level of nitrogen produced maximum bolls, more number of fruiting

sites which resulted in highest cotton yield.

Iqbal et al. (2003) conducted an experiment to determine the effect of nitrogen on seed

cotton yield of cotton cultivars at the Cotton Research Station Multan during 2001-02.

Three cotton cultivars (i.e. MNH-552, MNH-554 and AC-134) were planted with

different nitrogen levels (0, 75, 125, 175 and 250 kg ha-1). They reported that application

of nitrogen fertilizer above 175 kg ha-1 neither extended the flowering period and nor

increased seed cotton yield significantly. Therefore, it is clear that excessive nitrogen

application rate can delay maturity and boll opening, thus the excessive nitrogen

application may be avoided.

It is simply recognized that nitrogen supply has a marked effect on vegetative and

reproductive growth and thus some producers have a tendency to attempt to increase

maximum potential of a crop by applying higher than recommended nitrogen rates. The

performance of a cultivar is different in nitrogen absorption during the growth period

19
because of its ability to mobilize nitrogen within the plant at different levels. The

excessive nitrogen application especially in combination with moisture availability can

delay maturity, reduce harvesting and ginning percentage and also promote boll

shedding, disease and insect attack. Profound understanding about the fate of nitrogen in

cotton may be helpful to improve the nitrogen efficiency, plant development, cotton yield

and avoid excessive nitrogen fertilization. Boquet and Breitenbeck, (2000) studied the

effect of nitrogen (0, 84 and 168 kg ha-1) on up-taking and partitioning of nitrogen and

dry matter of Deltapine-41 cotton cultivar during 1989-90 at Louisiana State University

Agricultural Center Northeast Research Station near St. Joseph, LA. Plant samples were

collected 28, 48 and 71 days after planting. The nitrogen contents and aerial biomass of

plant components were determined. It was observed that maximum nitrogen uptake

occurred between 48 and 71 days after planting which was 2.9 and 4.3 kg ha-1 d-1 for

cotton receiving 84 and 168 kg N ha-1 respectively. Furthermore, nitrogen assimilation in

leaves and lower bolls was 15-40% more with the application of 168 kg N ha-1 at the end

of effective bloom than plants receiving 84 kg N ha-1. It is also observed that maximum

total dry matter of 15637 kg ha-1 was obtained with168 kg N ha-1.

In cotton crop nitrogen stress has great influence on boll load and new growing bolls that

resulted in reduced yield as primarily deficit in nitrogen reduced light interception

because of smaller leaf area index. Jackson and Gerik, (1990) planned a greenhouse

experiment located at Temple, TX during 1987-88. Cotton cultivar Stoneville-213 was

sown individually in each pot at a depth of 15 mm. At two weeks intervals, a solution of

NH4NO3 was applied at the rate of zero, 18, 36, 72 and 144 m mole of N per pot. They

reported that the maximum number of bolls and weight were observed at the higher

nitrogen rate (144 m mole).

20
Nitrogen deficiency in cotton is considered a yield limiting factor through a decrease in

leaf area expansion, CO2 assimilation capacity and low productivity that is often

associated with low fiber quality. Alagudaral et al. (2006) conducted a study to evaluate

the effect of different levels and time of nitrogen application on yield and quality of

hybrid cotton TCHB 213 during 1998 and 1999 at Tamil Nadu Agricultural University,

Coimbatore. They used three levels of nitrogen (i.e. 80,120 and 160 kg N ha-1) at

different time of application viz; two equal splits (basal and 45 DAS), three equal splits

(basal, 45 DAS and 65 DAS), four equal splits (basal, 45 DAS, 65 DAS and 85 DAS) and

control (zero nitrogen fertilizer). Further, they reported that nitrogen significantly

influenced the seed cotton yield and the highest rate of 160 kg N ha-1 produced the

highest seed cotton yield of 2547 kg ha-1 relative to other levels. This enhance in yield

was jointly due to relative contribution of various yield components like number of

sympodial branches, bolls number and boll weight. Again nitrogen applied as four equal

splits registered the highest seed cotton yield of 2356 kg ha-1 and was at par with three

splits. Further, seed index and lint index values were higher where nitrogen was applied

at the rate of 160 kg ha-1.

21
2.4 Sowing Time and Plant Density

Cotton growth and development are influenced with environmental conditions and

seasonal management practices. Being a peculiar shape of cotton plant, sowing time and

plant density are considered the key factors for high yield cotton production technology.

A lot of work has been done on these agronomic factors individually but a very few

studies are available involving both factors together. Such as Dong et al. (2005)

conducted an experiment at Cotton Research Center Jinan (Northern Shandong, China)

during 2001-04 to determine the effect of sowing dates normal (April 15) and late (early

May) with different plant density (3.0, 4.5, 6.0 and 7.5 plants m-2) on yield and fiber

traits. They indicated that the growth and development of late planted cotton had taken

place more quickly than normal sown cotton and on average lint yield was not influenced

significantly by plant density or planting date but significant interactions between

planting date and density for lint yield were observed during both the years.

Bazari (1999) also studied the planting dates (April 10, 21 and May 01 during 1996 and

April 20, 30 and May 10 during 1997 with row spacing of 60, 70 and 80 cm and plant

spacing maintained at 10, 15 and 20 cm and seed cotton yield and fiber quality of cotton

cultivar “Varamin” was observed at Agriculture Research Station Birjand, Iran. They

showed that early sowing dates produced 5 and 30% higher lint yield than the crop sown

during last week of April and first week of May respectively while plant spacing 10 cm

gave 4 and 11 % more yield than other plant spacing of 15 and 20 cm respectively.

Further, they reported that the early sowing dates (April 10, 20) with plant distance of 10

cm produced higher seed cotton yield than other combinations of sowing dates and plant

density. The significant interactions of sowing date and plant density were also observed

here. However, a few contrasting evident are also available that showed non-significant

interactions between plant populations and planting dates.

22
Similarly, E.L Tabbkh et al. (2001) conducted field experiments at the Agricultural

Research Station, Egypt during the years of 1999 and 2000 and studied four planting

dates (March 01, April 01, 15 and May 01) with four plant populations (83333, 111109,

166666 and 222218 plants ha-1). They reported that delay in sowing date with low plant

density significantly decreased seed cotton yield, boll weight, number of bolls, days to

first flower and first open boll. However, lint percentage, seed index, fiber length,

uniformity ratio, fiber strength and fineness were not significantly affected by sowing

dates in both the years. Again interactions of sowing dates and plant density were

significant for seed cotton yield and boll weight.

Impact of plant populations (16988, 33976, 67952 and 135904 plants ha-1) with planting

dates (April 22, 30 and May 10, 2002), (April 21, May 01 and 13, 2003), and (April 25

May 8 and 20, 2004) on seed cotton yield, fiber qualities and crop maturity were studied

at Mississippi Delta. They found that there were significant interactions among plant

density and sowing dates however, they also reported that these factors had individual

influence on yield and fiber quality. Thus, early planting treatments produced

significantly greater seed cotton yield than the other planting dates through out the study.

Moreover, higher plant populations produced significantly more seed cotton yield than

the lowest plant population. The early sown crop produced higher lint percentage and

micronaire than late sown crop and late sown crop with low plant population delayed

crop maturity (Wrather et al., 2008). Similar studies were also conducted in Turkey,

Bozbek et al. (2006) studied three sowing dates (May 01, 15 and 30) with four plant

spacing i.e. 5, 10, 15 and 20 cm at Cotton Research Institute Nazilli, Aegean Region

during 1999-2000. They reported that early planting on May 01 produced 8.34 and 34.13

% more seed cotton yield than crop sown on May 15 and 30 respectively. However, plant

spacing of 15 cm produced higher seed cotton at early sowing than other spacings. They

23
observed that higher plant density produced more plant dry matter than low plant density

and the highest seed cotton yield were obtained when crop was sown earlier with higher

planting density however, the interactions between plant density and dates were non-

significant.

Most of the scientists are agreed that plant spacing should be adjusted according to the

phenology of cotton cultivar. Thus, to determine the optimum plant spacing, Memon et

al. (2002) studied the four different planting dates (April 15, May 01, 15 and June 01)

with three plant spacings of 15, 22.5 and 30 cm at Central Cotton Research Institute,

Sakrand Pakistan, during 1999-2000. They reported that the crop sown on May 01

produced 10.6, 2.0 and13.0 % increase in yield than other sowing dates of April 15, May

15 and June 01 sowing respectively. However, maximum yield was obtained when the

plants were spaced at 22.5 cm which gave an increase of 6.0 and 14.0 % over 15.0 and

30.0 cm spacing, respectively.

Similarly, Berry et al. (2008) also conducted field experiments at three different locations

(Virginia, North Carolina and Louisiana USA) in Suffolk during 2005-06 to determine

the impact of plant population and planting date on growth, fruiting, lint yield and fiber

quality of cotton. Thus, they studied plant populations of 4.9, 9.8 and 16.4 plants m-2 with

two planting dates ranging from April 24 to May 5 and May 15 to May 25 were targeted.

However, actual plant population achieved were 5.2, 9.2 and 11.2 plants m-2 (Virginia

2005), 5.2, 9.2 and 15.4 plants m-2 (North Carolina 2005) 5.6, 9.5 and 17.1 plants m-2

(Louisiana 2005) 4.9, 6.6 and 12.8 plants m-2 (Virginia 2006) 5.9, 8.9 and 12.8 plants m-2

(North Carolina 2006). They reported that higher plant population decreased number of

bolls per plant and main stem nodes at Virginia while, at North Carolina these variables

were increased within an increase in plant population. Similarly early planting date

produced more number of bolls per plant and main stem nodes at Virginia while at North

24
Carolina late planting gave more high-node ratio, main stem nodes and bolls number.

Increased plant population produced higher lint yield and lint percentage at two locations

Virginia and North Carolina. However, in Louisiana early planting gave more lint yield

and lint percentage than late planting. Moreover, early planting produced higher

micronaire value at all the locations while higher fiber length and uniformity percentage

was obtained with late sown crops.

2.5 Plant Density and Nitrogen Fertilizer

The potential of a crop could be realized when sown at the proper spacing, optimum time

and judicious use of nutrients. Nitrogen is widely considered one of the major essential

nutrients for plant growth. However, proper nitrogen application in upland cotton can

often be viewed as more of an art rather than science. Generally, cotton producers have

the impression that narrow spaced cotton requires higher nitrogen rates than wide spaced

cotton (Boquet, 2005; Pettigrew, et al., 2006). Some reports about the interactive effects

of varying plant densities and fertilizer rates are reviewed in the following section.

Ali et al. (2007) studied three levels of nitrogen fertilizer (25, 50 and 75 kg acre-1) with

three plant populations of 30000, 40000 and 50000 plants acre-1 during 2004-05 at four

Adaptive Research Farms i.e. Vehari, Sargodha, Rahim Yar Khan and Karor. They

reported that higher nitrogen rates of 50 and 75 kg acre-1 produced 6.31 and 12.30 %

higher seed cotton yield than 25 kg N acre-1, respectively. Higher plant populations of

40000 and 50000 plants acre-1 produced 9.36 and 14.23 % higher seed cotton yield than

low plant population of 30000 plants acre-1. It was also observed that maximum seed

cotton yield was obtained at the highest nitrogen rate of 75 kg acre-1 with the highest

plant population of 50000 plants acre-1 and the interaction of nitrogen and plant

population were found to be non significant.

25
Clawson et al. (2006) conducted an experiment at Agriculture Experimental Station

Farm, Burleson County, USA during 2000-2002 to study the nitrogen requirements of

ultra narrow row (UNR) and conventional row (CR). They studied four nitrogen levels of

0, 50, 101 and 151 kg ha-1 with spacing of 19, 38 (UNR) and 76 cm (CR) and reported

that plant height and main stem nodes per plant decreased with a decrease in row spacing

while the tallest nitrogen rate of 151 kg ha-1 produced significantly the tallest plants and

maximum main stem nodes than lower nitrogen rates. Further, lint yield was increased

with each increment of nitrogen and lint yield was not influenced significantly with row

spacing.

Field experiments at Mid South USA, Louisiana State University, Agriculture Centre

during 1997 to 2000 were conducted with plant populations (128000, 256000 and 385000

plants ha-1) and nitrogen levels (90, 112, 134 and 157 kg ha-1) on irrigated and rainfed

cotton. He also made a comparison of ultra-narrow row spacing (25 cm) cotton with wide

row spacing (102 cm) cotton at a plant population of 116000 plants ha-1 fertilized with 90

kg N ha-1. He reported that an increase in plant density in irrigated cotton decreased lint

yield, boll number and boll weight in comparison with an increase in plant density of rain

fed cotton which has no effect on lint yield and number of bolls m-2. Maximum yield of

UNR cotton were attained with plant densities in the range of 128000 to 256000 ha-1 and

nitrogen level of 90 kg ha-1 (Boquet, 2005). Cotton cultivar CIM-443- was sown at 10, 20

and 30 cm spacing with nitrogen fertilizer at the rate of 0, 50, 100 kg N ha-1 at Central

Cotton Research Institute, Multan during 1998. They observed that maximum seed cotton

yield was obtained at 10 cm distance between plants with the highest rate of nitrogen

(100 kg ha-1) by Hussain et al. (2000).

After review of the extant literature, we understand that the crop potential can be

managed if sown at proper spacing and optimum time along with judicious use of

26
nutrients and protection measures. Cotton cultivars differ in their growth characteristics

such as earliness, height, fruit development, maturity, yield potential and fiber properties.

Thus, sowing the crop earlier produces taller plants and higher boll number, which

ultimately result in higher seed cotton yield. Moreover, early planting increases the

length, strength, and maturity percentage of fiber. Nitrogen contributes significantly in

plant growth, development and yield. The potential overuse of nitrogen results in

excessive vegetative growth, harvest delays, increasing pest pressure and nitrate

contamination of groundwater. Therefore, the agronomists always focus on the optimum

use of nitrogen in a newly released cultivar. It produces higher plants, more nodes, more

boll number and weight, more seed index, maximum total dry matter, higher lint yield

and seed cotton yield. Whereas the deficient application of nitrogen decreases boll

number, reduces boll weight and increases the shedding percentage which ultimately

decreases the seed cotton yield. There is a potential for higher yield and quality in narrow

plant population which results in increased maturity, more vegetative and reproductive

dry matter, more boll number, higher lint percentage, higher seed cotton yield and

increased fiber strength.

27
 MATERIALS AND METHODS

3.1 General Materials and Methods

The research work reported was conducted at the experimental area of the Central Cotton

Research Institute, Multan (Pakistan), during the years 2004-07 on silt loam soils. The

studies were carried out with the objectives to determine the response of cotton cultivars

to sowing time, plant density and nitrogen fertilizer on plant growth and seed cotton

yield.

The experimental site was situated at latitude 300,12N, longitude 710, 28E, altitude 123

m. The cotton belt of Pakistan stretches between latitude 290 N and 370 N, diagonally

through out the country, spreading over the length of 960 km and the breadth of about

320 km. The area lies in an arid subtropical continental climate. To harvest profitable

seed cotton yield, cotton cultivation is possible only with supplemental irrigation. The

main features of agro-climatic conditions are very hot, as temperature in summer may

shoot up to 48-500C and wide range of diurnal temperatures (Ashraf et al., 1994).

To diagnose the fertility status of experimental site, a number of soil samples were

collected from two depth ranges i.e. 0-15 cm and 15-30 cm. For this purpose, three cores

were taken from each depth. Samples of each soil depth range were dried, ground and

passed through 2 mm sieve and mixed thoroughly separately. Two composite samples

were prepared i.e. one for 0-15 cm and other 15-30 cm depth range. Physical and

chemical analyses of the samples were done. In addition, to the amount of nutrients

available in the soil, the proposed levels of nitrogen fertilizer were applied in the form of

Urea (46% N) and basal dose of phosphorus was applied at the rate of 50 kg P2O5 in the

28
form of TSP (46% P2O5). After harvesting the crop soil analysis was repeated. Results

regarding soil chemical analysis are given below

Table 1- Physical and chemical analysis of the experimental site (2004-2007)

Before sowing After harvesting

Characteristics
0-15 cm 15-30 cm 0-15 cm 15-30 cm

EC dSm-1 2.61-2.68 2.70-2.76 2.58-2.66 2.69-2.75

Soil pH (1:1) 8.00-8.06 8.09-8.14 8.01-8.03 8.04-8.07

Organic Matter (%) 0.83-0.86 0.81-0.83 0.85-0.89 0.82-0.85

NO3-N (mg kg-1) 5.50-5.58 4.49-4.52 5.65-5.70 4.60-4.66

NaHCO3-P (mg kg-1) 13.0-13.7 11.6-12.2 12.4-12.7 11.3-11.8

NH4OAC-K (mg kg-1) 120-125 112-120 111-118 104-110

Sand (%) 16 14 16 14

Soil Separates Silt (%) 57 60 57 60

Clay (%) 27 26 27 26

Texture class Silt loam Silt loam Silt loam Silt loam

The land was prepared with cultivator and bed-furrows were made with special ridger 75

cm apart from each other. The beds were properly shaped with bed shaper and pre-

emergence herbicide (Pendimethaline) at the rate of 82.5 g ha-1 a.i was applied to control

weeds. The furrows were irrigated and delinted cotton seeds were dibbled manually on

the same day in the moist soil on its proper place. The furrows were irrigated 72 hours

after dibbling to have successful seed emergence. However, subsequent irrigations were

given at 10 days interval uptil crop maturity. Each experiment was replicated thrice and

was laid out in a randomized complete block design with split plot arrangements.

29
The phosphorus fertilizer was applied at the rate of 50 kg ha-1 in the form of Triple Super

Phosphate (46 % P2O5) at the time of seed bed preparation before making bed-furrows

and the nitrogen fertilizer was applied in three splits as per treatment in the form of Urea

(46%N). The crop was protected against insects and sprayed as per requirement at

threshold levels.

3.2 Observations
The following observations were recorded:

(i) Meteorological data at Central Cotton Research Institute Multan, Pakistan during

the cropping season 2004-2007 (Appendices. I, II, III and IV).

(ii ) Quality of irrigation water used during entire crop season.

Table-2 Quality of canal and tube well water used for irrigation season
Characteristics Canal water Tube well water

Electrical conductivity (µS cm-1) 558 690

pH 8.00 8.40

Ca2++ Mg2+ (meq L-1) 3.67 9.66

Na+ (meq L-1) 1.91 7.24

CO32- (meq L-1) nil nil

HCO3- (meq L-1) 2.60 8.72

Cl- (meq L-1) 0.98 3.30

SO42+ (meq L-1) 2.00 4.88

Sodium adsorption ratio (m mol-1)0.05 1.41 3.30

Residual sodium carbonate (meq L-1) 0.10 nil

Five plants from each treatment (free of mechanical or terminal damage or without

obvious defects) were individually selected for recording data on earliness indices. The

30
observations were recorded at three physiological crop growth stages i-e at square

initiation (25 DAS), flower initiation (40 DAS) and at boll split initiation (80 DAS). The

following morpho-phenological events were recorded and were based on calendar days.

i.) Days from planting to first flower bud (28-30 DAS)

ii.) Days from planting to first flower (40-45 DAS)

iii.) Days from planting to first boll split (70-80 DAS)

Data on plant structure were recorded by measuring the height of each plant from

cotyledon node to the top of the terminal bud and recording the number of nodes on the

main stem. Five plants from each treatment were randomly selected and plant height was

recorded in cm. Results are presented on the basis of average plant height. Data on

number of bolls were counted from randomly selected four plants in each treatment at

maturity and converted to per square meter basis. Seed cotton of fully opened one

hundred bolls from each treatment was picked, sun dried, weighed and than averaged to

per boll weight basis. Data on fruit production were recorded from four plants harvested

at different physiological stages of growth and than computed on a per square meter

basis.

a. Number of total fruiting positions (squares, flowers and bolls abscised and

retained)

b. Number of total fruit (squares, flowers and bolls) whether immature or mature

(ones) according to Wells and Meredith., (1984).

For dry matter production data were recorded according to Munro (1971). For this

purpose four healthy Plants were individually selected from each treatment. The whole

plant was taken from each plot and partitioned into leaves, stem and fruiting forms

31
according to the method of Mullins and Burmester (1990). Mature bolls were separated

into lint, seed and burs. Flowers, squares, immature bolls and burs from mature bolls

were included with the bur fraction. The material was dried in an oven at 70oC to a

constant temperature and weighed. Dry weight was recorded on per unit land area basis

according to method described by Wells and Meredith Jr., (1984). The vegetative dry

weight (VDW) included leaf dry weight (LDW) and stem dry weight (SDW) portions.

The results were presented on per square meter basis. The total dry weight was calculated

by adding vegetative dry weight and reproductive organs dry weight (RDW). The

reproductive- vegetative ratio (RVR) was calculated by dividing RDW by VDW (Jones et

al., 1996).

Crop Growth Rate (CGR)

It is the ratio of total increase in weight to the total time taken

W2 = dry weight at time t2

W1 = dry weight at time t1

Total dry weight was recorded at 50, 100 and 150 days after planting.

Relative Growth Rate

It is the ratio of log of increase in weight rate to the time taken

W2 = dry weight at time t2

W1 = dry weight at time t1

RGR = Relative growth rate

Total dry weight was recorded at 50, 100 and 150 days after planting.

32
Data on seed cotton yield were recorded at the time of crop harvest by measuring the

yield on plot basis and then converted into kg ha-1.

After ginning, lint percentage was determined by dividing the lint weight by the seed

cotton weight and multiplying by 100.

Data on seed index were recorded by taking the weight of 100 seeds (g).

Seed cotton will be ginned on electric powered sample saw gin to separate lint from

the cotton seed. Testing of lint samples were carried out on high volume instrument

(HVI-900 A, Uster Ltd; USA) at 8.5% moisture level in the lint. For this purpose, lint

samples were conditioned at 20 + 2oC and 65 + 2o % relative humidity for 24 hours.

The instrument was calibrated according to the standard methods prescribed in its

instruction manual (1994). The qualitative characteristics lint viz. fiber length, fiber

fineness, fiber strength, fiber elongation, fiber uniformity ratio and colour grades in

terms of reflectance degree of fiber (Rd %) and yellowness degree of fiber (Hunter’s

+b) were determined. The testing procedure was adopted as reported by ASTM

Standard (1997) while fiber maturity ratio was measured by using Shirley Fineness –

Maturity Tester (ASTM, 1993). The colour grades were classified according to the

USDA Classification System (Taylor, 1998).

3.3 Chemical Analysis

Composite soil samples were collected (each consisting of three cores) from the

experimental site before applying fertilizer treatments. The soil samples were also

collected before and after harvesting cotton crop. The soil profile was probed to the depth

of 0-15 and 15-30 cm. These samples were air-dried, ground and passed through <2mm

33
sieve. Soil analyses were carried out by method described by Ryan et al. (2001). All the

calculations were made on oven dried soil weight basis.

i. Electrical conductivity (EC) of saturated soil extract was measured (Method 5.2)

using conductivity meter (Chemtrix-70, Chemtrix, Inc.,Hellsboro, USA).

ii. pH of saturated soil paste (pHs) was measured by pH meter model Jenway 3310

(Felsted, Essex, England) by using combination electrode (Method 5.1).

iii. Organic matter: One gram of soil sample was mixed with 20 ml concentrated

H2SO4 and 10 ml 1N K2Cr2O7. Added 200 ml distilled water and 10 ml

concentrated ortho-phosphoric acid and titrated it with 0.5 M [(NH4)2SO4. FeSO4.

6H2O)] and two blank samples were also run (Method 5.4).

iv. Nitrate nitrogen (NO3-N) was measured by a spectrophotometric method using

chromotropic acid (Method 6.1.4).

v. Extractable phosphorus was determined following sodium bicarbonate procedure

(Method 6.2).

vi. Exchangeable potassium was determined by using 1N NH4OAc extractant

(Method 6.3).

v. Particle size distribution was determined by hydrometer method using

[(NaPO3)13] as a deflocculent (Method 4.2).

vi. Textural class of the soil was determined using the USDA textural triangle

(Method 4.2).

34
3.4 Water Analysis

The water samples were analyzed by employing methods described by Richards (1954).

i. Electrical conductivity: with the help of conductivity meter, Chemtrix-70 (Method

72).

ii. pH by pH meter model Jenway 3310 using combination electrode (Method 21).

iii. Calcium and Magnesium by titration with EDTA using NH4Cl+NH4OH buffer

and Eriochrome Black-T indicator (Method 7).

iv. Sodium by flame photometer (Method 80b).

v. Carbonates and bicarbonates by titration with standard H2SO4 using

phenolphthalein and methyl orange indicators, respectively (Method 82)

vi. Chloride by titration with AgNO3using K2CrO4 indicator (Method 84)

vii. Sulphate by difference: [TSS in meq L-1 – (CO32-+ HCO3-+Cl-]

viii. Sodium Adsorption Ratio (SAR): SAR=Na+ [ Ca+2+ Mg+2)\2]1\2 when

concentration of soluble cations is expressed in mmol L-1 (Method 20 b)

ix. Residual Sodium Carbonate(RSC): RSC = [(CO3-2 +HCO3- ) - (Ca+2+Mg+2)] (all

concentrations expressed in meq L-1)

3.5 Statistical analysis

Data were analyzed using Fisher’s analysis of variance techniques and least significant

difference (LSD) at 5% probability was applied to compare the differences among the

treatments (Steel, et al; 1997). Computer programmer Microsoft Excel was used to

prepare the graphs.

35
4.1 Experiment – I

Title- Cultivars response to sowing time and plant spacing

The studies were conducted at Central Cotton Research Institute, Multan, Pakistan on a

silt loam soil having pH (8.09), EC (2.72 dSm-1) and organic matter (0.82%) during 2004.

The objective of this study was to determine the appropriate plant spacing and best

sowing time for specific cotton cultivars

Experimental Design

The experiment was replicated thrice and laid out in a randomized complete block design

with split plot arrangements with three factors.

Treatments

Sowing dates

D1 May-10

D2 June-01

D3 June-20

Plant Spacings

S1 15 cm

S2 30 cm

S3 45 cm

Cultivars

C1 CIM-473

C2 CIM-482

36
4.1.1 Materials and Methods

The experiment was conducted to the response of cotton cultivars to various sowing dates

and plant spacings. Cotton cultivars CIM-473 and CIM-482 were planted at three

different sowing dates starting from May 10 to June 20 at twenty days interval with three

plants spacings (15, 30, 45 cm). The experiment was planted on bed and furrow 75cm

apart which were made in well prepared dry soil and shaped properly with bed shaper.

The planting was done by dibbling of seed manually on May 10, June 01 and June 20.

Sowing dates were kept in main plots, plant spacing in the sub plots and cultivars in the

sub sub plots. Nitrogen at the rate of 150 kg ha-1 in three split doses was applied in all

sowing dates i.e. May-10 (June 01, July 05, and August 15), June 01 (June 01, July 05

and August 15) and June 20 (June 20, July 15 and August 15). Cultural practices such as

inter-culturing, irrigation and plant protection measures were adopted as per requirement

of the crop. Analytical results of the soil samples collected at pre planting and after the

harvest of crop are given in Table- 3.

Table-3 Chemical analysis of the experimental site (2004)

Characteristics Before sowing After harvesting
Depth (cm) Depth (cm)
0-15 15-30 0-15 15-30
EC dSm-1 2.68 2.76 2.66 2.75
Soil pH (1:1) 8.06 8.11 8.03 8.07
Organic Matter (%) 0.83 0.81 0.85 0.82
NO3-N (mg kg-1) 5.50 4.49 5.65 4.60
NaHO3-P (mg kg-1) 13.0 12.0 12.5 11.8
NH4OAC–K (mg kg-1) 125.0 120.0 118.0 110.0

37
4.1.3 Results

Plant height (cm)

Results showed that there were significant differences among different treatments i.e.

cultivars, spacing and sowing dates (Table-4.1.1). Cultivar CIM-482 produced

significantly (P≤0.05) taller plants than CIM-473. Further the cv. CIM-482 produced

significantly taller plants on each sowing dates (P≤ 0.05 and 0.01). However, CIM-482

produced the tallest plant (125.3 cm) in early sown crop on May 10 and the shorter plants

(95.7 cm) produced by CIM-473 in the late sown on June 20 (Fig 4.1.1). It is evident

from the results that each increase in spacing produced shorter plants and the tallest

plants of 110.5 cm on average basis were produced with 15 cm spacing while the shortest

plants were found with 45 cm spacing showing significant (P≤0.01) differences between

these treatments. Although 30 cm spacing treatments produced shorter plants than 15 cm

spacing but the differences were not significant.

Results also showed that each delay in sowing produced shorter plants. Thus, crop sown

early on May 10, gave the tallest plants (115.0 cm) and crop sown late on June 20,

produced significantly (P≤0.01) the shortest plants of 99.2 cm. However, crop sown on

June 01, tended to produce shorter plant than May 10 treatment but the differences were

not statistically significant.

It is obvious from the results that the interactions of cultivars with sowing dates were

found to be significant (Fig.4.1.1) These differences might have occurred due to the

cultivar CIM-482 which produced taller plants in early sown crops (May 10 and June 01).

38
Table-4.1.1 Effect of sowing dates, cultivars and plant spacing on plant height
(cm) of cotton crop
Sowing Plant spacing (cm)
Cultivars
dates 15 30 45 Means
CIM-473 110 105 99 104.7
May-10 CIM-482 125 126 125 125.3
Means 117.5 115.5 112 -
CIM-473 102 101 98 100.3
June-01 CIM-482 122 120 118 120.0
Means 112 110.5 108 -
CIM-473 98 94 95 95.7
June-20 CIM-482 106 105 97 102.7
Means 102 99.5 96 -
SEs
Sowing date 2.20
Cultivars 0.68
Plant spacing 1.51
DxC 1.18
DxS 2.62
CxS 2.14
DxCxS 3.71
LSD (5%)
Sowing date 6.11
Cultivars 1.67
Plant spacing 3.12
DxC 6.44
DxS Ns
CxS Ns
DxCxS Ns
Sub effects of different variables
Sowing dates Plant height Cultivars Plant height Plant spacing Plant height
(cm) (cm) (cm) (cm)
May-10 115.0a CIM-473 100.2b 15 110.5a
June-01 110.2a 30 108.5a
CIM-482 116.0a
June-20 99.2b 45 105.3b
D:Sowing dates C:Cultivars S:Plant spacing

39
 140

120

Plant height (cm)

100

80

60

40

20

0
10-May 01-June 20-June
Sowing Date

CIM-473 CIM-482

Fig. 4.1.1 Interactive effects of cultivars and sowing dates at maturity on plant
height (cm)

Nodes per plant

Results showed that cultivars, sowing dates and spacings produced variable number of

nodes per plant (Table-4.1.2). It is clear from the results that each delay in sowing

showed a slight decrease in number of nodes per plant but this decrease was not

statistically significant. Similarly, an increase in spacing showed a slight decrease in node

number; again this decrease was not significant statistically. However, it is observed that

cultivar CIM-482 produced significantly a higher number of nodes (33.8) than CIM-473

that produced a lower number of 29.4 (P≤0.01).

It is obvious from the results that interactions between different treatments of cultivars,

spacings and sowing dates were non-significant.

40
Table-4.1.2 Effect of sowing dates, cultivars and plant spacing on nodes per plant
of cotton crop
Sowing Plant spacing (cm)
Cultivars
dates 15 30 45 Means
CIM-473 31.00 30.00 28.67 29.89
May-10 CIM-482 35.00 36.00 36.00 35.67
Means 33.00 33.00 32.4 -
CIM-473 30.33 29.00 29.00 29.44
June-01 CIM-482 35.00 35.00 35.00 35.00
Means 32.67 32.00 32.0 -
CIM-473 29.33 28.33 29.00 28.89
June-20 CIM-482 31.00 32.00 29.00 30.67
Means 30.17 30.17 29.00 -
SEs
Sowing date 1.02
Cultivars 0.70
Plant spacing 1.01
DxC 1.21
DxS 1.74
CxS 1.42
DxCxS 2.46
LSD (5%)
Sowing date n.s
Cultivars 1.71
Plant spacing n.s
DxC n.s
DxS n.s
CxS n.s
DxCxS n.s
Sub effects of different variables
Sowing Nodes Cultivars Nodes Plant Nodes
dates plant-1 plant-1 Spacing (cm) plant-1
May-10 32.78 CIM-473 29.41b 15 31.95
June-01 32.22 30 31.72
CIM-482 33.78a
June-20 29.78 45 31.13

Inter-nodal distance (cm)

Data presented in Table (4.1.3) showed that inter-nodal distance of the cotton cultivars

was influenced by different treatments of spacings and sowing dates.

However, both the cultivars did not show a significant difference in inter-nodal distance,

but similar observation like that of number of nodes per plant was observed here, as each

41
increase in spacings showed a decrease in inter-nodal distance but the differences were

not significant statistically. Again, each delay in sowing showed decrease in inter-nodal

distance and significantly (P≤0.05) the highest distance of 3.5cm was observed in crop

sown early on May 10, while the lowest (3.4cm) distance was observed in crop sown late

on June 20. Again, interactions of cultivars, spacings and sowing dates were found to be

non-significant.

Table-4.1.3 Effect of sowing dates, cultivars and plant spacing on inter-nodal

distance (cm) of cotton crop
Sowing Plant spacing (cm)
Cultivars
dates 15 30 45 Means
CIM-473 3.55 3.50 3.41 3.49
May-10 CIM-482 3.57 3.50. 3.47 3.51
Means 3.56 3.50 3.44 -
CIM-473 3.40 3.48 3.38 3.42
June-01 CIM-482 3.49 3.43 3.37 3.43
Means 3.45 3.46 3.38 -
CIM-473 3.38 3.36 3.28 3.34
June-20 CIM-482 3.42 3.28 3.34 3.35
Means 3.40 3.32 3.31 -
SEs
Sowing date 0.04
Cultivars 0.05
Plant spacing 0.05
DxC 0.09
DxS 0.08
CxS 0.07
DxCxS 0.12
LSD (5%)
Sowing date 0.10
Cultivars n.s
Plant spacing n.s
DxC n.s
DxS n.s
CxS n.s
DxCxS n.s
Sub effects of different variables
Sowing dates Inter-nodal Cultivars Inter-nodal Plant Inter-nodal
distance (cm) distance (cm) Spacing (cm) distance (cm)
May-10 3.50a CIM-473 3.42 15 3.47
June-01 3.43ab 30 3.43
CIM-482 3.43
June-20 3.35b 45 3.38

42
Square initiation (days)

Results showed (Table-4.1.4) that square initiation differed significantly by cultivars,

sowing dates and plant spacing treatments.

Table-4.1.4 Effect of sowing dates, cultivars and plant spacing on square initiation
(days) of cotton crop
Sowing Plant spacing (cm)
Cultivars
dates 15 30 45 Means
CIM-473 25.67 26.00 26.67 26.11
May-10 CIM-482 27.00 27.67 28.67 27.78
Means 26.34 26.84 27.67 -
CIM-473 25.00 25.67 26.00 25.56
June-01 CIM-482 26.00 27.00 27.67 26.89
Means 25.5 26.34 26.84 -
CIM-473 25.00 25.67 26.00 25.56
June-20 CIM-482 26.00 26.67 26.67 26.45
Means 25.50 26.17 26.34 -
SEs
Sowing date 0.11
Cultivars 0.19
Plant spacing 0.15
DxC 0.32
DxS 0.26
CxS 0.21
DxCxS 0.36
LSD (5%)
Sowing date 0.31
Cultivars 0.45
Plant Spacing 0.30
DxC n.s
DxS n.s
CxS n.s
DxCxS n.s
Sub effects of different variables
Sowing dates Square Cultivars Square Plant spacing Square
initiation initiation (cm) initiation
(days) (days) (days)
May-10 26.95a CIM-473 25.74b 15 25.78c
June-01 26.23b 30 26.45b
CIM-482 27.04a
June-20 26.01b 45 26.95a

Cultivar CIM-473 significantly showed earliness in first squaring (25.7 DAS) than CIM-

482 which showed late squaring (27.0 DAS).Data also showed that delay in sowing

43
tended to earlier the squaring of crop. However crop sown early on May 10 delayed

significantly the squaring initiation than crops sown later on June 01 and June 20

(P≤0.01). On contrary increase in plant spacing delayed significantly squaring of the crop

(P≤0.05 and 0.01). The interactions between different treatments of sowing dates,

cultivars and spacing were found to be non- significant.

Flower initiation (days)

The observation like that of squaring was also appeared for flower initiation (Table-

4.1.5). Cultivar CIM-473 showed significantly early flower initiation (45.9 DAS) than

CIM-482 (47.4 DAS). It is evident from the results that delay in sowing significantly

earlier the flowering of crop (P≤0.05). However increase in spacing delayed flowering

initiation and each increase in spacing delayed significantly flowering (P≤0.01). Results

also showed that 15 cm spacing (narrow) significantly earlier the flowering than 45 cm

spacing (wider) on each sowing date (i.e. May 10, June 01 and June 20). Similarly, plant

spacing of 15 and 45 cm in early sown crop on May 10 delayed significantly flowering

than crop sown later on June 01 and June 20.

It is evident from the results that interactions between spacing and sowing dates were

found to be significant (Fig. 4.1.2). These significant effects might have occurred due to

45 cm spacing which prolonged the vegetative growth resulting delayed flower initiation.

44
Table-4.1.5 Effect of sowing dates, cultivars and plant spacing on flower initiation
(days) of cotton crop
Sowing Plant spacing (cm)
Cultivars
dates 15 30 45 Means
CIM-473 46 47 47 46.7
May-10 CIM-482 48 48 49 48.3
Means 47.0 47.5 48.0 -
CIM-473 45 46 46 45.7
June-01 CIM-482 47 48 48 47.7
Means 46.0 47.0 47.0 -
CIM-473 45 45 46 45.3
June-20 CIM-482 46 46 47 46.3
Means 45.5 45.5 46.5 -
SEs
Sowing date 0.25
Cultivars 0.14
Plant spacing 0.15
DxC 0.24
DxS 0.25
CxS 0.21
DxCxS 0.36
LSD (5%)
Sowing date 0.68
Cultivars 0.34
Plant spacing 0.30
DxC n.s
DxS 0.52
CxS n.s
DxCxS n.s
Sub effects of different variables
Sowing dates Flower Cultivars Flower Plant spacing Flower
initiation initiation (cm) initiation
(days) (days) (days)
May-10 47.5a CIM-473 45.9b 15 46.2c
June-01 46.7b 30 46.7b
CIM-482 47.4a
June-20 45.8c 45 47.2a

45
 50

Days from planting to 1st flower

45

40
15cm 30cm 45cm
Plant spacing (cm)

10-May 01-June 20-June

Fig. 4.1.2 Interactive effects of sowing dates and plant spacing on flower
initiation (days)

Boll split initiation (days)

The observation like that of squaring and flower initiation was also found for boll split

initiation that was influenced significantly by different treatments of cultivars, spacings

and sowing dates (Table-4.1.6). Cultivar CIM-473 significantly earlier (two days) boll

split initiation than CIM-482. Results showed that each delay in sowing significantly

(P≤0.05 and 0.01) earlier the boll split initiation. It is also observed that cultivar CIM-473

significantly (P≤0.01) earlier the boll split initiation than CIM-482 on each sowing date.

Data showed that each increase in spacing delayed significantly (P≤0.01) boll split

initiation. However, cultivar CIM-482 delayed significantly boll split initiation than CIM-

473 with each spacing (15, 30 and 45 cm) on each sowing date. Similarly, each cultivar

significantly earlier the boll split initiation with 15 cm spacing (narrow) than wider

spacing (45 cm) on each sowing date.

46
The interactions between sowing dates and cultivar were found to be significant.

Similarly the interactions of sowing dates, cultivar and plant spacings were also found to

be significant (Fig-4.1.3-4). These significant effects might have occurred because the

cultivar CIM-482 with 45 cm spacing prolonged the vegetative growth that delayed

flower initiation resulting in delayed boll split initiation. However interactions of cultivar,

sowing date and plant spacing were found to be non-significant.

Table-4.1.6 Effect of sowing dates, cultivars and plant spacing on boll split initiation
(days) of cotton crop
Sowing Plant spacing (cm)
Cultivars
dates 15 30 45 Means
CIM-473 83 84 84 83.7
May-10 CIM-482 84 86 86 85.3
Means 83.5 85.0 85.0 -
CIM-473 81 82 83 82.0
June-01 CIM-482 84 85 85 84.7
Means 82.5 83.5 84.0
CIM-473 81 81 82 81.3
June-20 CIM-482 82 83 84 83.0
Means 81.5 82.0 83.0 -
SEs
Sowing date 0.13
Cultivars 0.08
Plant spacing 0.17
DxC 0.14
DxS 0.29
CxS 0.24
DxCxS 0.42
LSD (5%)
Sowing date 0.37
Cultivars 0.20
Plant spacing 0.35
DxC 0.35
DxS n.s
CxS n.s
DxCxS 0.86
Sub effects of different variables
Sowing dates Boll split Cultivars Boll split Plants pacing Boll split
initiation initiation (cm) initiation
(days) (days) (days)
May-10 84.5a CIM-473 82.3b 15 82.5c
June-01 83.4b 30 83.5b
CIM-482 84.3a
June-20 82.2c 45 84.0a

47
 CIM-473

90

Days from planting to 1st boll

80

70
15cm 30cm 45cm

CIM-482

90
Days from planting to 1st boll

80

70
15cm 30cm 45cm
Plant spacing (cm)

10-May 01-June 20-June

Fig.4.1.3 Interactive effects of cultivars, sowing dates and plant spacing on boll
split Initiation (days)

48
 90

Days from planting to 1st boll split

80

70
10-May 01-June 20-June
Sowing Dates

CIM-473 CIM-482

Fig.4.1.4 Interactive effects of cultivars and sowing dates on boll split initiation
(days)

Number of bolls m-2

The results showed that there were significant differences among different treatments i.e.

cultivars, sowing dates and spacing (Table-4.1.7). Cultivar CIM-473 produced

significantly (P≤0.01) more bolls (91.5 m-2) than CIM-482 produced lower number of

bolls (72.1 m-2). The maximum bolls (99.9 m-2) were produced with 15 cm spacing while

the minimum boll number (63.7 m-2) were produced with 45 cm spacing and differences

between treatments were found to be significant (P≤0.01).

It is obvious from the result that boll number decreased significantly (P≤0.01) with each

increase in spacing. Similar observation like that of spacing appeared here that with each

delay in sowing significantly reduced the boll number (P≤0.01). The highest number of

boll (97.5 m-2) were produced with early sown crop on May 10 that was followed by the

treatment of crop sown on June 01 with boll number of 85.5 m-2 while the lowest number

of 62.5 m-2 was observed with late sown crop on June 20.

49
Results showed that the interactions between cultivars and plant spacing were found to be

significant (Fig-4.1.5) because both the cultivars produced highest boll number with 15

cm spacing while the lowest number of bolls was observed with 45 cm spacing. This

significant effect might have occurred due to the maximum number of plants had been

maintained in 15 cm spacing.

Table-4.1.7 Effect of sowing dates, cultivars and plant spacing on number of bolls
m-2 of cotton crop
Sowing Plant spacing (cm)
Cultivars
dates 15 30 45 Means
CIM-473 125.3 113.7 84.6 107.9
May-10 CIM-482 105.1 83.1 72.9 87.0
Means 115.2 98.4 78.8 -
CIM-473 113.7 101.4 72.9 96.0
June-01 CIM-482 96.2 70.4 58.3 75.0
Means 105.0 85.9 65.6 -
CIM-473 89.3 70.1 52.5 70.6
June-20 CIM-482 69.9 52.5 40.8 54.4
Means 79.6 61.3 46.7 -
SEs
Sowing date 2.51
Cultivars 2.55
Plant spacing 2.53
DxC 4.42
DxS 4.38
CxS 3.57
DxCxS 6.19
LSD (5%)
Sowing date 6.98
Cultivars 6.25
Plant spacing 5.21
DxC ns
DxS ns
CxS 7.36
DxCxS ns
Sub effects of different variables
Sowing Bolls Cultivars Bolls Plant spacing Bolls
dates m-2 m-2 (cm) m-2
May-10 97.5a CIM-473 91.5a 15 99.9a
June-01 85.5b 30 81.9b
CIM-482 72.1b
June-20 62.5c 45 63.7c

50
 120
110
100
90

Bolls (m )
-2
80
70
60
50
40
15cm 30cm 45cm
Plant Spacing (cm)

CIM-473 CIM-482

Fig.4.1.5 Interactive effects of cultivars and plant spacing on boll m-2

Boll weight (g)

Results relating to boll weight revealed that there were significant differences among

different treatments of cultivars, spacing and sowing date (Table-4.1.8). Data showed that

the cultivar CIM-482 gave significantly higher boll weight than CIM-473 (P≤0.01).

Spacing treatments showed that each increase in spacing increased significantly the boll

weight (P≤0.01).

The crop sown with 45 cm spacing produced the highest boll weight of 2.79 (g) while the

lowest boll weight of 2.47 (g) was observed with 15 cm spacing. Obviously, 15 cm

spacing treatments also gave lower boll weight than 30 cm spacing that produced

significantly higher boll weight of 2.60 (g). Results showed that delay in sowing

increased the boll weight significantly (P≤0.01). Thus the maximum boll weight of 2.68

(g) was produced with late sown crops on June 20 and the lowest weight of 2.57 (g) was

observed with early sown crops on May 10. Similarly, crop sown on June 01, also gave

significantly higher boll weight than crop sown on May 10.

51
It is evident from the results that interactions between cultivars and spacing treatments

were found to be significant. These effects might be due to the fact that both the cultivars

increased significantly (P≤0.01) boll weight with each increase in spacing. However, all

other interactions were observed to be non-significant.

Table-4.1.8 Effect of sowing dates, cultivars and plant spacing on boll weight (g) of
cotton crop
Sowing Plant spacing (cm)
Cultivars
Dates 15 30 45 Means
CIM-473 2.35 2.47 2.61 2.48
May-10 CIM-482 2.46 2.65 2.85 2.65
Means 2.41 2.56 2.73 -
CIM-473 2.45 2.50 2.62 2.52
June-01 CIM-482 2.51 2.69 2.92 2.71
Means 2.48 2.60 2.77 -
CIM-473 2.47 2.55 2.71 2.58
June-20 CIM-482 2.55 2.73 3.02 2.77
Means 2.51 2.64 2.87 -
SEs
Sowing date 0.02
Cultivars 0.01
Plant spacing 0.02
DxC 0.02
DxS 0.03
CxS 0.03
DxCxS 0.05
LSD (5%)
Sowing date 0.05
Cultivars 0.03
Plant spacing 0.04
DxC n.s
DxS n.s
CxS 0.05
DxCxS n.s
Sub effects of different variables
Sowing dates Boll weight (g) Cultivars Boll weight (g) Plant spacing Boll weight (g)
(cm)
May-10 2.57c CIM-473 2.53b 15 2.47c
June-01 2.62b 30 2.60b
CIM-482 2.71a
June-20 2.68a 45 2.79a

52
Seed cotton yield (kg ha-1)

The results in Table (4.1.9) indicated that different treatments i.e. cultivars, spacing and

sowing dates had significant effect on seed cotton yield. Cultivar CIM-473 produced

significantly more seed cotton yield (2097 kg ha-1) than CIM-482 that gave lower yield of

1657 kg ha-1 (P≤0.01). It is clear from the results that each increase in spacing decreased

significantly (P≤0.01) seed cotton yield of both cultivars (Fig-4.1.6). However,

significantly the highest seed cotton yield of 2814 kg ha-1 was produced by the cultivar

CIM-473 with 15 cm spacing while the lowest yield of 1018 kg ha-1 was produced by

CIM-482 when sown at 45 cm spacing. The data also showed that on over all means of

each increase in spacing reduced significantly (P≤0.01) the seed cotton yield. Thus, the

highest seed cotton yield of 2202 kg ha-1 produced with 15 cm spacing whereas,

significantly (P≤0.01) lowest yield of 1525 kg ha-1 was produced with 45 cm spacing.

It is evident from the result that seed cotton yield was significantly (P≤0.05 and 0.01)

influenced by sowing date. As each delay in sowing date reduced significantly the seed

cotton yield and the highest yield of 2176 kg ha-1 was produced when crop was sown

early on May 10 and the lowest yield of 1439 kg ha-1 was produced with late sown crop

on June 20.

Result showed that the interactions between cultivars and plant spacing were also

significant (Fig.4.1.6). Both the cultivars produced highest yield with 15 cm spacing

while the lowest yields were recorded with 45 cm spacing. This significant effect might

have resulted due to the maximum number of plants had been maintained in 15 cm

spacing.

53
Table-4.1.9 Effect of sowing dates, cultivars and plant spacing on seed cotton yield
(Kg ha-1) of cotton crop
Sowing Plant-spacing (cm)
Cultivars
Dates 15 30 45 Means
CIM-473 2814 2541 1892 2416
May-10 CIM-482 2210 1906 1693 1936
Means 2512 2224 1793 -
CIM-473 2697 2394 1714 2268
June-01 CIM-482 2034 1723 1543 1767
Means 2366 2059 1629 -
CIM-473 1874 1661 1289 1608
June-20 CIM-482 1582 1208 1018 1269
Means 1728 1435 1154 -
SEs
Sowing date 51.73
Cultivars 53.47
Plant spacing 54.89
DxC 92.61
DxS 95.07
CxS 77.63
DxCxS 134.46
LSD (5%)
Sowing date 143.82
Cultivars 130.99
Plant spacing 113.08
DxC Ns
DxS Ns
CxS 159.91
DxCxS Ns
Sub effects of different variables
Sowing Seed cotton Cultivars Seed cotton Plant Seed cotton
dates yield yield Spacing yield
(kg ha-1) (kg ha-1) (cm) (kg ha-1)
May-10 2176a CIM-473 2097a 15 2202a
June-01 2018b 30 1906b
CIM-482 1657b
June-20 1439c 45 1525c

54
 3000

2500

Seed cotton yield (kg ha-1 )

2000

1500

1000

500
15cm 30cm 45cm
Plant Spacing (cm)

CIM-473 CIM-482

Fig.4.1.6 Interactive effects of cultivars and plant spacing on seed cotton yield
(kg ha-1)

Ginning outturn percentage (%)

Data revealed that different treatments of cultivars influenced significantly the ginning

out turn (GOT) percentage (Table-4.1.10). Cultivar CIM-473 produced significantly

(P≤0.05) higher GOT (40.3%) while CIM-482 gave lower GOT of 38.9%. However, the

early sown crop tended to produce higher GOT (%) percentage but the differences

between different treatments were not statistically significant. It is also observed that

different treatments of spacing did not affect on GOT (%).

Similarly, the interactions between different treatments were found to be non-significant.

55
Table-4.1.10 Effect of sowing dates, cultivars and plant spacing on ginning
outturn percentage (%) of cotton crop
Sowing Plant-spacing (cm)
Cultivars
dates 15 30 45 Means
CIM-473 41.1 40.7 40.9 40.9
May-10 CIM-482 39.2 39.7 39.9 39.6
Means 40.2 40.2 40.4 -
CIM-473 40.5 40.6 39.5 40.2
June-01 CIM-482 38.8 39.1 38.9 38.9
Means 39.7 39.9 39.2 -
CIM-473 39.8 40.2 39.6 39.9
June-20 CIM-482 38.2 38.1 38.2 38.2
Means 39.0 39.2 38.9 -
SEs
Sowing date 0.34
Cultivars 0.14
Plant spacing 0.28
DxC 0.24
DxS 0.48
CxS 0.39
DxCxS 0.67
LSD (5%)
Sowing date n.s
Cultivars 0.33
Plant spacing n.s
DxC n.s
DxS n.s
CxS n.s
DxCxS n.s
Sub effects of different variables
Sowing G.O.T Cultivars G.O.T Plant spacing G.O.T
dates (%) (%) (cm) (%)
May-10 40.3 CIM-473 40.3a 15 39.6
June-01 39.6 30 39.8
CIM-482 38.9b
June-20 39.1 45 39.5

Seed index (g)

Data showed that seed index varied among different treatments of cultivars and sowing

dates (Table-4.1.11). It is observed that seed index of cultivar CIM-482 (10 g) was

significantly higher than CIM-473 that gave lower index of 9.2 (g). Results also showed

that delay in sowing decreased the seed index but differences between different

56
treatments were not statistically significant. However, plant spacing did not affect the

seed index of cotton cultivars.

It is evident from the results that interactions between different treatments of cultivars,

sowing dates and plant spacing were also found to be significant These significant effects

might have occurred due to the cultivar CIM-482 which tended to produce higher seed

index on each sowing date with all spacings (i.e. 15, 30 and 45 cm).

Table-4.1.11 Effect of sowing dates, cultivars and plant spacing on seed index (g) of
cotton crop
Sowing Plant spacing (cm)
Cultivars
dates 15 30 45 Means
CIM-473 9.5 9.3 8.7 9.2
May-10 CIM-482 10.3 9.9 10.3 10.2
Means 9.9 9.6 9.5 -
CIM-473 8.9 9.0 9.6 9.2
June-01 CIM-482 10.1 10.0 9.8 10.0
Means 9.5 9.5 9.7 -
CIM-473 9.3 9.3 9.1 9.2
June-20 CIM-482 9.6 9.9 9.8 9.8
Means 9.5 9.6 9.5 -
SEs
Sowing date 0.10
Cultivars 0.11
Plant spacing 0.10
DxC 0.19
DxS 0.17
CxS 0.14
DxCxS 0.24
LSD (5%)
Sowing date n.s
Cultivars 0.26
Plant spacing n.s
DxC n.s
DxS n.s
CxS n.s
DxCxS 0.49
Sub effects of different variables
Sowing dates Seed index Cultivars Seed index Plant spacing Seed index
(g) (g) (cm) (g)
May-10 9.7 CIM-473 9.2b 15 9.6
June-01 9.6 30 9.6
CIM-482 10.0a
June-20 9.5 45 9.6

57
Total fruiting points m-2

The results in Table (4.1.12) indicated that different spacings and sowing dates

influenced significantly the fruiting points of the cultivars. Cultivar CIM-473 produced

significantly (P≤0.01) higher number of fruiting points than CIM-482.

Table-4.1.12 Effect of sowing dates, cultivars and plant spacing on total fruiting
points m-2of cotton crop
Sowing Cultivars Plant-spacing (cm)
dates 15 30 45 Means
CIM-473 416 348 275 346
May-10 CIM-482 374 315 282 324
Means 395.0 331.5 278.5 -
CIM-473 404 350 259 338
June-01 CIM-482 342 326 263 310
Means 373.0 338.0 261.0 -
CIM-473 330 298 214 281
June-20 CIM-482 309 241 210 253
Means 319.5 269.5 212.0 -
SEs
Sowing date 2.19
Cultivars 2.69
Plant spacing 3.13
DxC 4.66
DxS 5.42
CxS 4.42
DxCxS 7.66
LSD (5%)
Sowing date 6.08
Cultivars 6.59
Plant spacing 6.44
DxC n.s
DxS 11.16
CxS 9.11
DxCxS 15.79
Sub effects of different variables
Sowing dates Fruiting Cultivars Fruiting Plant Fruiting
points points spacing points
m-2 m-2 (cm) m-2
May-10 335a CIM-473 322a 15 363a
June-01 324b 30 313b
CIM-482 296b
June-20 267c 45 251c

58
 450

400

350
points (m-2)
Fruiting

300

250

200

150
15cm 30cm 45cm
Plant Spacing (cm)

CIM-473 CIM-482

Fig.4.1.7 Interactive effects of cultivars and plant spacing on total fruiting

points m-2
It is observed from the results that both the cultivars decreased the number of fruiting

points significantly (P≤0.01) with each increase in spacings. However, on average basis

the highest fruiting point number of 363 m-2 was produced in 15 cm spacing while the

lowest number (251 m-2) in 45 cm spacing. Similarly, each delay in sowing produced

significantly (P≤0.01) a lesser number of fruiting points. The highest number of 335 m-2

was observed in early sown crop on May 10, while the lowest number of 267 m-2 was

produced in late sown crop on June 20. It is evident from the results that interactions of

different treatments of cultivars, spacings and sowing dates were found to be significant

(Fig.4.1.7-9). However, the interactions between cultivars and sowing dates were not

significant. The significant interactions between cultivars and plant spacings might have

occurred because of the higher number of plants in narrow plant spacing. Again the

significant interactions between spacing and sowing dates were observed because of

higher number of plants in narrow spacing on each sowing dates. However, the

59
 significant effect of cultivars, spacing and sowing dates might have occurred due to

higher number plants of both cultivars in narrow spacing on each sowing date.

CIM-473

450

400
Fruiting points (m )
-2

350

300

250

200

150
15cm 30cm 45cm
Plant spacing (cm)

10-May 01-June 20-June

CIM-482
450

400

350
Total fruiting
points (m-2)

300

250

200

150
15cm 30cm 45cm
Plant Spacing

10-May 01-June 20-June

Fig 4.1.8 Interactive effect of sowing dates, plant spacing and cultivars on

fruiting points m-2

60
 450

400

350

points (m )
-2
Fruiting
300

250

200

150
15cm 30cm 45cm
Plant Spacing (cm)

10-May 01-June 20-June

Fig.4.1.9 Interactive effects of sowing dates and plant spacing on total fruiting
points m-2

Total intact fruits m-2

Results relating to intact fruits m-2 revealed that there were significant differences among

different treatments of cultivars, sowing dates and spacings (Table-4.1.13). Data showed

that the cultivar CIM-473 gave significantly (P≤0.01) higher number of intact fruits than

CIM-482. Data also showed that there were significant (P≤0.01) differences among

different treatments of spacings and each increase in plant spacing reduced significantly

the number of intact fruits m-2. However the highest number of intact fruits (99.0 m-2)

was found with 15 cm spacing and the lowest number (75.0 m-2) was observed in

treatments of 45 cm spacings. It is clear from the results that delay in sowing caused a

significant (P≤0.05 and 0.01) decrease in intact fruits and the highest intact fruits (98.0

m-2) were observed with early sown crop on May 10 while the lowest number of intact

fruits (72.0 m-2) was produced in late sown crop on June 20. It is evident from the results

that interactions between cultivars, spacing and sowing dates were statistically found to

be non-significant.
61
Table-4.1.13 Effect of sowing dates, cultivars and plant spacing on intact fruits m-2
of cotton crop
Sowing Cultivars Plant spacing (cm)
dates 15 30 45 Means
CIM-473 120 104 88 104
May-10 CIM-482 104 88 84 92
Means 112.0 96.0 86.0 -
CIM-473 112 100 80 97
June-01 CIM-482 92 88 76 85
Means 102.0 94.0 78.0 -
CIM-473 88 80 64 77
June-20 CIM-482 80 64 56 67
Means 84.0 72.0 60.0 -
SEs
Sowing date 1.87
Cultivars 2.23
Plant spacing 2.47
DxC 3.86
DxS 4.27
CxS 3.49
DxCxS 6.04
LSD (5%)
Sowing date 5.19
Cultivars 5.46
Plant spacing 5.08
DxC n.s
DxS n.s
CxS n.s
DxCxS n.s
Sub effects of different variables
Sowing Intact fruits Cultivars Intact fruits Plant spacing Intact fruits
dates m-2 m-2 (cm) m-2
May-10 98.0a CIM-473 93.0a 15 99.3a
June-01 91.0a 30 87.3b
CIM-482 81.0b
June-20 72.0b 45 75.0c

Shedding Percentage (%)

The results in Table (4.1.14) showed that shedding percentage (%) in different treatments

of cultivars, sowing dates and plant spacing were found to be non significant. Cultivar

CIM-473 gave lower shedding percentage than CIM-482 but the differences were not

62
significant. Each delay in sowing tended to increase shedding percentage but, the

differences were not significant statistically among different sowing dates.

Table-4.1.14 Effect of sowing dates, cultivars and plant spacing on shedding %age
of cotton crop
Sowing Cultivars Plant spacing (cm)
dates 15 30 45 Means
CIM-473 71 70 68 70
May-10 CIM-482 72 72 70 71
Means 71.5 71.0 69.0 -
CIM-473 72 71 69 71
June-01 CIM-482 73 73 71 72
Means 72.5 72.0 70.0 -
CIM-473 73 73 70 72
June-20 CIM-482 74 73 73 73
Means 73.5 73.0 71.5 -
SEs
Sowing date 1.46
Cultivars 1.09
Plant spacing 1.69
DxC 1.88
DxS 2.94
CxS 2.40
DxCxS 4.15
LSD (5%)
Sowing date n.s
Cultivars n.s
Plant spacing n.s
DxC n.s
DxS n.s
CxS n.s
DxCxS n.s
Sub effects of different variables
Sowing dates Shedding Cultivars Shedding Plant spacing Shedding
%age %age (cm) %age
May-10 70.5 CIM-473 71.0 15 72.5
June-01 71.5 30 72.0
CIM-482 72.0
June-20 72.5 45 70.2

Similarly, each increase in spacing showed a decrease in shedding percent and again the

differences were not significant. It is obvious from the results that interactions between

cultivars, sowing dates and plant spacings were not significant.

63
Vegetative dry matter (g m-2)

Vegetative dry matter of cultivars was influenced significantly by different treatments of

spacings and sowing dates (Table-4.1.15). Cultivar CIM-482 produced significantly

(P≤0.01) more vegetative dry matter at maturity than CIM-473.It is clear from the data

that each delay in sowing increased significantly the vegetative dry matter. The highest

dry matter of 475.1 (g m-2) was produced by the crop sown late on June 20 and the lowest

dry matter (394.6g m-2) was observed with early sown crop on May 10. Although, both

the cultivars showed increase in vegetative dry matter with each delay in sowing,

however, CIM-473 did not produced significantly different vegetative dry matter in early

sown crops (May 10 and June 20) Where as CIM-482 when sown late on June 20 did not

show significant differences statistically than crop sown on June 01. On contrary, each

increase in spacing significantly decreased the vegetative dry matter at maturity. Thus,

the maximum dry matter of 458.0 (g m-2) was produced with 15 cm spacing (narrow)

while the minimum dry matter (395.5 g m-2) was produced with 45 cm spacing (wider).

Further, each spacings with each delay in sowing significantly increased the dry matter.

It is evident from the results that interactions between sowing date and cultivars were

found to be significant. This significant effect might have occurred because both the

cultivars showed significantly more vegetative growth with each delay in sowing date

that resulted higher vegetative dry matter

Similarly, the interactions between sowing date and plant spacings were also found to be

significant. These significant effects might have occurred because delay in sowing with

narrow spacings promoted vegetative growth resulted in higher dry matter production.

64
Table-4.1.15 Effect of sowing dates, cultivars and plant spacing on vegetative dry
matter (g m-2) of cotton crop
Sowing Cultivars Plant spacing (cm)
dates 15 30 45 Means
CIM-473 369.8 347.1 297.4 338.1
May-10 CIM-482 492.5 457.6 403.3 451.1
Means 431.2 402.4 350.4 -
CIM-473 395.5 369.3 310.3 358.4
June-01 CIM-482 503.3 496.8 453.3 484.5
Means 449.4 433.1 381.8 -
CIM-473 472.2 452.3 427.2 450.6
June-20 CIM-482 514.9 502.4 481.4 499.6
Means 493.6 477.4 454.4 -
SEs
Sowing date 7.80
Cultivars 4.90
Plant spacing 5.08
DxC 8.49
DxS 8.79
CxS 7.18
DxCxS 12.44
LSD (5%)
Sowing date 21.69
Cultivars 12.02
Plant spacing 10.46
DxC 20.81
DxS 18.12
CxS n.s
DxCxS n.s
Sub effects of different variables
Sowing Vegetative Cultivars Vegetative Plant Vegetative
dates dry matter dry matter Spacing dry matter
(gm-2) (gm-2) (cm) (gm-2)
May-10 394.6c CIM-473 382.4b 15 458.1a
June-01 421.5b 30 437.6b
CIM-482 478.4a
June-20 475.1a 45 395.5c

Reproductive dry matter (g m-2)

Results indicated that there were significant differences among different treatments of

cultivars, sowing dates and spacings for reproductive dry matter (Table-4.1.16). In

contradiction to vegetative dry matter, cultivar CIM-473 produced significantly (P≤0.01)

more reproductive dry matter than CIM-482 at maturity. It is clear from the data that each

65
delay in sowing decrease the reproductive dry matter and significantly the highest

reproductive dry matter of 539.5 (g m-2) was produced by the crop sown early on May 10

and the lowest dry matter (428.0g m-2) was produced with the late sown crop on June 20.

Results also showed that both the cultivars showed a significant decrease in reproductive

dry matter with each delay in sowing, except CIM-473 when sown on June 01 which did

not show significant decrease in dry matter when sown early on May 10. Similarly each

increase in spacing also significantly decreased the reproductive dry matter at maturity.

Thus, the highest reproductive dry matter of 543.9 (g m-2) was produced with narrow

spacing while the lowest dry matter (430.0 g m-2) was produced with wider spacing. It is

observed that each spacings caused a significant decrease in dry matter with each delay in

sowing except the treatments of spacing when sown on June 01 did not show significant

differences statistically. Similar observation was produced when each sowing date with

each increase in spacing decreased significantly the reproductive dry matter, except crop

sown on June 20 when 30 cm spacing did not differ significantly.

It is obvious from the results that interactions between sowing dates and cultivars were

found to be significant. These significant effects might have occurred due to the varietals

behavior and sowing times which resulted in higher reproductive dry matter of CIM-

473.Similarly the interactions between sowing times and plant spacings were also found

to be significant. Again these significant effects occurred due to delay in sowing which

promoted the vegetative growth that resulted in lower reproductive dry matter production.

66
Table-4.1.16 Effect of sowing dates, cultivars and plant spacing on reproductive
dry matter (g m-2) of cotton crop
Sowing Cultivars Plant spacing (cm)
Dates 15 30 45 Means
CIM-473 664.3 608.5 514.2 595.7
May-10 CIM-482 536.2 490.9 422.4 483.2
Means 600.3 549.7 468.3 -
CIM-473 654.2 592.8 467.4 571.5
June-01 CIM-482 494.3 475.8 390.6 453.6
Means 574.3 534.3 429.0 -
CIM-473 490.5 463.5 432.7 462.2
June-20 CIM-482 423.7 403.6 354.1 393.8
Means 457.1 433.6 393.4 -
SEs
Sowing date 13.12
Cultivars 6.09
Plant spacing 8.44
DxC 10.55
DxS 14.61
CxS 11.93
DxCxS 20.67
LSD (5%)
Sowing date 36.48
Cultivars 14.93
Plant spacing 17.38
DxC 25.85
DxS 30.10
CxS n.s
DxCxS n.s
Sub effects of different variables
Sowing dates Reproductive Cultivars Reproductive Plant spacing Reproductive
dry matter dry matter (cm) dry matter
(gm-2) (gm-2) (gm-2)
May-10 539.5a CIM-473 543.1a 15 543.9a
June-01 512.6ab 30 505.9b
CIM-482 443.5b
June-20 428.0b 45 430.2c

Reproductive-vegetative ratio

Data presented in Table (4.1.17) showed that reproductive-vegetative ratio (RVR) was

influenced significantly by different treatments of cultivars, sowing dates and spacings.

67
Table-4.1.17 Effect of sowing dates, cultivars and plant spacing on reproductive-
vegetative ratio of cotton crop
Sowing Cultivars Plant spacing (cm)
dates 15 30 45 Means
CIM-473 1.79 1.75 1.73 1.76
May-10 CIM-482 1.09 1.07 1.05 1.07
Means 1.44 1.41 1.39 -
CIM-473 1.65 1.61 1.51 1.59
June-01 CIM-482 0.98 0.96 0.86 0.93
Means 1.32 1.29 1.19 -
CIM-473 1.04 1.02 1.01 1.02
June-20 CIM-482 0.82 0.80 0.76 0.79
Means 0.93 0.91 0.89 -
SEs
Sowing date 0.03
Cultivars 0.02
Plant spacing 0.02
DxC 0.03
DxS 0.04
CxS 0.03
DxCxS 0.05
LSD (5%)
Sowing date 0.09
Cultivars 0.04
Plant spacing 0.04
DxC 0.08
DxS n.s
CxS n.s
DxCxS n.s

Sub effects of different variables

Sowing dates Reproductive Cultivars Reproductive Plant Reproductive
vegetative vegetative Spacing vegetative
ratio ratio (cm) ratio
May-10 1.42a CIM-473 1.46a 15 1.23a
June-01 1.26b 30 1.20a
CIM-482 0.93b
June-20 0.91c 45 1.16b

Cultivar CIM-473 produced significantly (P≤0.01) higher RVR values than CIM-482.

Results also showed that each delay in sowing significantly decreased the RVR. It is

evident from the results that CIM-473 produced significantly higher RVR values on

each sowing dates than CIM-482.

68
 3

2.5

Reproductive vegetative ratio

2

1.5

0.5

0
10-May 01-June 20-June
Sowing Dates

CIM-473 CIM-482

Fig.4.1.10 Interactive effects of cultivars and sowing dates on reproductive-

vegetative ratio

However both the cultivars showed significantly lower RVR values with each delay in

sowing. It is clear that each increase in spacing tended to decrease the reproductive

vegetative ratio values. Thus, the lowest value of 1.16 was observed with 45 cm spacing

that significantly different with 15 and 30 cm spacings.

It is obvious from the results that interactions between sowing dates and cultivars were

found to be significant (Fig.4.1.10). These significant differences might have occurred

because the vegetative growth of both the cultivars increased with the delay in sowing

dates that resulted in lower reproductive-vegetative ratio in the late sown crops.

Total plant dry matter (g m-2)

Results revealed (Table-4.1.18) that different spacings influenced significantly the total

dry matter of both the cultivars. Each increase in spacing decreased significantly

(P≤0.01) the total dry matter of plant at maturity. It is clear from the results that at each

sowing date, each increase in spacing showed a significant decrease in plant dry matter

except, 30 cm spacing on June 20 did not show significant decrease statistically.

69
Table-4.1.18 Effect of sowing dates, cultivars and plant spacing on plant dry
matter (g m-2) of cotton crop
Sowing Cultivars Plant spacing (cm)
dates 15 30 45 Means
CIM-473 1034.1 955.6 811.6 933.8
May-10 CIM-482 1028.7 948.5 825.7 934.3
Means 1031.4 952.1 818.7 -
CIM-473 1049.7 962.1 777.7 929.8
June-01 CIM-482 997.6 972.6 841.9 937.4
Means 1023.7 967.4 809.8 -
CIM-473 962.7 915.8 859.9 912.8
June-20 CIM-482 938.6 906.0 835.5 893.4
Means 950.7 910.9 847.7 -
SEs
Sowing date 20.33
Cultivars 10.19
Plant spacing 12.76
DxC 17.64
DxS 22.11
CxS 18.05
DxCxS 31.26
LSD (5%)
Sowing date n.s
Cultivars n.s
Plant spacing 26.29
DxC n.s
DxS 45.54
CxS n.s
DxCxS n.s
Sub effects of different variables
Sowing Plant dry Cultivars Plant dry Plant spacing Plant dry
dates matter matter (cm) matter
(gm-2) (gm-2) (gm-2)
May-10 934.1 CIM-473 925.5 15 1001.9a
June-01 933.6 30 943.5b
CIM-482 921.7
June-20 903.1 45 825.4c

70
 CIM-473

1100

Plant dry matter (g m-2)

1000

900

800

700
15cm 30cm 45cm

CIM-482

1100
Plant dry matter (g m-2)

1000

900

800
15cm 30cm 45cm
Sowing Dates

10-May 01-June 20-June

Fig.4.1.11 Interactive effects of sowing dates and plant spacing on plant dry
matter of cultivars

71
Further, cultivar CIM-473 gave slightly more dry matter than CIM-482 but the

differences were not statistically significant. Similarly early sown crops tended to

produce higher dry matter and again the differences between different treatments were

not statistically significant.

It is evident from the results that interactions between different treatments of cultivars,

sowing dates and plant spacings were found to be significant (Fig.4.1.11). These

significant effects might have occurred because late sown crop with increased spacing

provided short growth period and less plant population which resulted in low dry matter

production. All other interactions were found to be non-significant.

Staple length (mm)

Data presented in Table (4.1.19) revealed that staple length of cotton cultivars was not

influenced by different treatments of sowing dates and plant spacings. However, the

cultivar CIM-482 produced slightly the longer staple as compared to CIM-473 but the

differences were not significant statistically. Similarly, each increase in spacing tended to

produce longer staple but again the differences were not significant statistically.

Results showed that the interactions between different treatments of cultivars, sowing

dates and plant spacing were also found to be non-significant

72
Table-4.1.19 Effect of sowing dates, cultivars and plant spacing on staple length
(mm) of cotton crop
Sowing Cultivars Plant spacing (cm)
Dates 15 30 45 Means
CIM-473 27.6 28.1 27.5 27.7
May-10 CIM-482 28.4 27.8 28.3 28.2
Means 28.0 28.0 27.9 -
CIM-473 27.5 28.0 27.5 27.7
June-01 CIM-482 28.0 28.0 27.3 27.8
Means 27.8 28.0 27.4 -
CIM-473 28.0 27.8 27.5 27.8
June-20 CIM-482 27.8 27.7 27.8 27.8
Means 27.9 27.8 27.7
SEs
Sowing date 0.11
Cultivars 0.16
Plant spacing 0.18
DxC 0.28
DxS 0.31
CxS 0.26
DxCxS 0.45
LSD (5%)
Sowing date n.s
Cultivars n.s
Plant spacing n.s
DxC n.s
DxS n.s
CxS n.s
DxCxS n.s
Sub effects of different variables
Sowing Staple length Cultivars Staple length Plant spacing Staple length
Dates (mm) (mm) (cm) (mm)
May-10 28.0 CIM-473 27.7 15 27.9
June-01 27.8 30 27.9
CIM-482 27.9
June-20 27.8 45 27.7

Micronaire value (ug inch-1)

The results in Table-4.1.20 indicated that micronaire value of different treatments of

cultivars and sowing dates gave significant effect. Thus, cultivar CIM-482 Produced

significantly (P≤0.01) more micronaire value of 4.7 ug inch-1 than CIM-473 that gave

lesser value of micronaire 4.2 ug inch-1. It is also observed from the results that

micronaire values significantly (P≤0.05 and 0.01) influenced by sowing dates.

73
Table-4.1.20 Effect of sowing dates, cultivars and plant spacing on micronaire (ug
inch-1) of cotton crop
Sowing Cultivars Plant-spacing (cm)
Dates 15 30 45 Means
CIM-473 4.4 4.3 4.2 4.3
May-10 CIM-482 4.8 4.8 4.8 4.8
Means 4.6 4.6 4.5 -
CIM-473 4.2 4.2 4.3 4.2
June-01 CIM-482 4.7 4.7 4.7 4.7
Means 4.5 4.5 4.5 -
CIM-473 4.2 4.2 4.1 4.2
June-20 CIM-482 4.7 4.6 4.6 4.6
Means 4.5 4.4 4.4
SEs
Sowing date 0.04
Cultivars 0.04
Plant spacing 0.04
DxC 0.06
DxS 0.06
CxS 0.05
DxCxS 0.09
LSD (5%)
Sowing date 0.10
Cultivars 0.09
Plant spacing n.s
DxC n.s
DxS n.s
CxS n.s
DxCxS n.s
Sub effects of different variables
Sowing dates Micronair Cultivars Micronair Plant spacing Micronair
(ug inch-1) (ug inch-1) (cm) (ug inch-1)
May-10 4.6a CIM-473 4.2a 15 4.5
June-01 4.5b 30 4.5
CIM-482 4.7b
June-20 4.4c 45 4.5
However, each delay in sowing date decreased significantly the micronaire value. The

highest micronair value of 4.6 ug inch-1 was produced when crop was sown early on May

10 that was followed by the crop sown on June 01 and significantly lowest value of

micronaire (4.4 ug inch-1) was observed with late sown crop on June 20. It is observed

from the results that different treatments of spacing did not affect the micronaire values.

The results also showed that the interactions between different treatments were found to

be non-significant.

74
Fibre strength (tppsi)
The results showed that treatments of cultivars, sowing dates and plant spacing did not

effect on fiber strength (Table-4.1.21). However, crop sown on June 01 tended to produce

higher fiber strength in all spacing than crop sown on May 10 and June 20 but the

differences between treatments were not statistically significant.

Table-4.1.21 Effect of sowing dates, cultivars and plant spacing on fiber strength
(tppsi) of cotton crop
Sowing Plant-spacing (cm)
Cultivars
Dates 15 30 45 Means
CIM-473 91.3 92.6 93.2 92.4
May-10 CIM-482 94.3 93.3 92.4 93.3
Means 92.8 93.0 92.8 -
CIM-473 95.1 94.5 95.0 94.9
June-01 CIM-482 94.0 93.6 94.4 94.0
Means 94.6 94.1 94.7 -
CIM-473 93.3 90.9 92.9 92.4
June-20 CIM-482 92.3 93.2 93.6 93.0
Means 92.8 92.1 93.3 -
SEs
Sowing date 1.05
Cultivars 0.62
Plant spacing 0.46
DxC 1.07
DxS 0.79
CxS 0.65
DxCxS 1.12
LSD (5%)
Sowing date n.s
Cultivars n.s
Plant spacing n.s
DxC n.s
DxS n.s
CxS n.s
DxCxS n.s
Sub effects of different variables
Sowing Fiber Cultivars Fiber Plant Fiber
dates strength strength Spacing strength
(tppsi) (tppsi) (cm) (tppsi)
May-10 92.9 CIM-473 93.2 15 93.4
June-01 94.5 30 93.1
CIM-482 93.4
June-20 92.7 45 93.6

75
Similar observation of results like that of micronaire value was also observed here that

interactions between different treatments were found to be non-significant.

Maturity ratio

It is clear from the data (Table-4.1.22) that maturity ratio value was slightly higher in crops

sown early on May-10 than late sown crop on June 01 and June 20.

Table-4.1.22 Effect of sowing dates, cultivars and plant spacing on maturity ratio
of cotton crop
Sowing Cultivars Plant-spacing (cm)
Dates 15 30 45 Means
CIM-473 1.08 1.09 1.09 1.09
May-10 CIM-482 1.10 1.09 1.11 1.10
Means 1.09 1.09 1.10 -
CIM-473 1.05 1.07 1.06 1.06
June-01 CIM-482 1.10 1.06 1.07 1.08
Means 1.08 1.07 1.07 -
CIM-473 1.07 1.07 1.09 1.08
June-20 CIM-482 1.09 1.08 1.08 1.08
Means 1.08 1.08 1.09 -
SEs
Sowing date 0.01
Cultivars 0.01
Plant spacing 0.01
DxC 0.01
DxS 0.01
CxS 0.01
DxCxS 0.02
LSD (5%)
Sowing date n.s
Cultivars n.s
Plant spacing n.s
DxC n.s
DxS n.s
CxS n.s
DxCxS n.s
Sub effects of different variables
Sowing dates Maturity Cultivars Maturity Plant spacing Maturity
ratio ratio (cm) ratio
May-10 1.10 CIM-473 1.08 15 1.08
June-01 1.07 30 1.08
CIM-482 1.09
June-20 1.08 45 1.09

76
However, the differences between different treatments were not significant. Interactions

between different treatments were also found to be non-significant.

Brightness (Rd)

Results showed that there were significant differences among different treatments of

cultivars and sowing dates for brightness of the fiber (Table-4.1.23).

Table-4.1.23 Effect of sowing dates, cultivars and plant spacing on brightness (Rd)
of cotton crop
Sowing Cultivars Plant spacing (cm)
Dates 15 30 45 Means
CIM-473 70.5 71.6 70.2 70.8
May-10 CIM-482 69.2 70.6 69.3 69.7
Means 69.9 71.1 69.8 -
CIM-473 71.3 70.9 71.9 71.4
June-01 CIM-482 71.2 70.3 69.1 70.2
Means 71.3 70.6 70.5 -
CIM-473 69.6 70.7 70.3 70.2
June-20 CIM-482 68.1 69.6 68.9 68.9
Means 68.9 70.2 69.6 -
SEs
Sowing date 0.32
Cultivars 0.49
Plant spacing 0.75
DxC 0.85
DxS 1.30
CxS 1.06
DxCxS 1.84
LSD (5%)
Sowing date 0.90
Cultivars 1.20
Plant spacing n.s
DxC n.s
DxS n.s
CxS n.s
DxCxS n.s
Sub effects of different variables
Sowing Brightness Cultivars Brightness Plant spacing Brightness
Dates (Rd) (Rd) (cm) (Rd)
May-10 70.3ab CIM-473 70.8a 15 70.0
June-01 70.8a 30 70.6
CIM-482 69.6b
June-20 69.6b 45 70.0

77
However, crop sown with 30 cm spacing tended to produce fiber of more brightness as

compared with other spacings but differences were not significant. It is clear from the

results that Cultivar CIM-473 produced significantly (P≤0.05) the fiber of more

brightness Results also showed that crop sown on June 01 produced the fiber of highest

brightness (70.8%) and the lowest brightness was observed in the crop sown late on June

20 (69.6%) where as, the crop sown early on May 10 was followed by June 01 that

produced brightness of 70.3%.

It is evident from the results that interactions of cultivars, spacings and sowing dates were

not found to be significant.

Yellowness (+b)

Results indicated that different sowing dates had significant affect on yellowness of

cotton fiber whereas, spacings and cultivars did not produced any significant effect on the

yellowness of cotton fiber (Table-4.1.24). Each delay in sowing showed an increase in

yellowness and the crops sown late on June 01 and June 20 produced significantly

(P≤0.05) more yellowness than crop sown early on May 10.

Results also showed that cultivar CIM-482 produced the fiber of more yellowness than

CIM-473 but the differences were not significant statistically. It is observed that the

interactions between different treatments of cultivars, spacing and sowing dates were

found to be non-significant.

78
Table-4.1.24 Effect of sowing dates, cultivars and plant spacing on yellowness (+b)
of cotton crop
Sowing Cultivars Plant spacing (cm)
Dates 15 30 45 Means
CIM-473 8.3 8.6 8.7 8.5
May-10 CIM-482 8.5 8.4 8.5 8.5
Means 8.4 8.5 8.6 -
CIM-473 8.9 8.5 8.7 8.7
June-01 CIM-482 8.8 9.0 8.7 8.8
Means 8.9 8.8 8.7 -
CIM-473 8.5 8.8 8.9 8.7
June-20 CIM-482 8.8 9.5 9.2 9.2
Means 8.7 9.2 9.1 -
SEs
Sowing date 0.11
Cultivars 0.13
Plant spacing 0.16
DxC 0.22
DxS 0.28
CxS 0.23
DxCxS 0.40
LSD (5%)
Sowing date 0.30
Cultivars n.s
Plant spacing n.s
DxC n.s
DxS n.s
CxS n.s
DxCxS n.s
Sub effects of different variables
Sowing dates Yellowness Cultivars Yellowness Plant spacing Yellowness
(+b) (+b) (cm) (+b)
May-10 8.5b CIM-473 8.6 15 8.7
June-01 8.8a 30 8.8
CIM-482 8.8
June-20 9.0a 45 8.8

79
4.1.4 DISCUSSION

Early planting of cotton in Pakistan avails the advantage of favorable environmental

conditions before the commencement of monsoon (spring; July to September) rain and

high temperature during flowering and fruit development. Further, cultivar selection is

also considered a key component in any cropping system, even more critical in ultra-

narrow row cotton production (Nichols et al., 2004). In experiment I, cultivar CIM-482

produced taller plants on each sowing dates along with increased number of nodes,

internodal distance and boll weight which ultimately produced significantly higher

vegetative dry matter at final harvest. However, shedding percentage was higher in these

treatments that reflected low seed cotton yield with longer staple length, higher

yellowness and courseness in fiber of CIM-482. On the other side, cultivar CIM-473

produced shorter plants with higher number of bolls m-2 that resulted significantly the

highest seed cotton yield per hectare. Thus, CIM-473 bearing higher intact fruits with

higher reproductive dry matter that resulted slightly higher total dry matter at final

harvest. Again CIM-473 produced higher ginning out turn percentage, higher brightness

and fineness in fiber. Up till now, a few research findings are reported on the

performance of cultivars grown in ultra-narrow rows however, cultivars planted at high

density from a columnar shape aiding in sufficient harvest (Wright, et al., 2000).

As cotton is considered to be a responsive crop to its surrounding environments and thus,

an appropriate sowing time is very important for growers to ensure optimum yield. One

of the most important agronomic considerations for grower is to ensure optimum yield

and quality of the crop. Cotton is a perennial crop and observed that crop sown early on

May 10 in this experiment produced taller plants with more number of nodes and inter-

nodal distance that resulted higher total plant dry matter. It is evident from the results that

early sown crop had more intact fruits that resulted higher number of bolls per unit area

80
with higher ratio of fiber maturity. While the late sown crop on June 01, produced more

vegetative dry matter with higher yellowness that is considered undesirable quality of

fiber by the textile industry, further, shedding percentage was also higher that resulted

lower seed cotton yield at final harvest. Thus, it is concluded that planting dates is very

important to harvest a profitable final yield and delay in planting resulting low seed

cotton yield (Pettigrew, et al., 2006; Ali, et al., 2005; Hassan, et al.,2005; Gormus and

Yucel, 2002). Partitioning of dry matter production was also recorded for different

sowing time and crop sown early on May 10 showed higher reproductive dry matter with

higher reproductive-vegetative ratio as well. The increased reproductive-vegetative ratio

indicates that better mobilization and utilization of photosynthates to develop bolls

resulted higher seed cotton yield with better fiber quality. These results were in line with

the findings of other scientists who reported that early planted cotton produced

significantly higher yield than normal planted ( lint, boll mass, seed mass and lint index,

maturity, bolls number, fiber elongation, strength of fiber, plant height and nodes )

further they reported that vegetative dry matter was also more in early planting than

normal planting of crop ( Ali, et al., 2005; Hassan, et al., 2005; Davidonis, 2004; Hassan,

et al., 2003; Akhter, et al., 2002; Pettigrew, 2002 ).

Cultivar potential is also dependent on optimum plant spacing and it directly effects soil

moisture extraction, light interception, humidity and wind movement. Plants were

evaluated at different plant spacing (i.e. 15, 30 and 45 cm) for different plant

characteristics. Plant sown at narrow spacing of 15 cm showed the highest values of all

growth parameters (plant height, nodes per plant, internodal distance, boll number. seed

cotton yield, reproductive dry matter, reproductive-vegetative ratio and total intact fruits)

The results were in accordance with the findings of Jones and Wells, 1998) who reported

that plant height increased with increasing population and delay in maturity was

81
associated with lower plant populations. Similar results were also found by (Bednarz et

al., 2006; Dong, et al., 2005) who reported that boll weight decreased as plant density

increased.

It is observed that interactions between cultivars and plant spacing were observed to be

significant for seed cotton yield, boll number and boll weight. Both the cultivars

produced the highest yield with narrow spacing of 15 cm and yield decreased with 45 cm

spacing. These results are in line with the findings of Jones (2001) who reported a

significant interaction of row spacing by cultivar for seed cotton yield. The data about

partitioning of dry matter production indicated that narrow spacing showed increased

reproductive dry matter and reproductive-vegetative ratio which ultimately increased the

seed cotton yield than the wider spacings. Similar results were also reported by the other

scientists that seed cotton yield for cotton planted in ultra narrow spacing was higher than

conventional row spacing (Jones, 2001).

82
4.2 Experiment– II

Title-Cultivars response to nitrogen application and plant spacing

The present studies were carried out, at Central Cotton Research Institute Multan,

Pakistan, during 2005 on a silt loam soil having pH; 8.05, EC; 2.68 dSm-1 and organic

matter; 0.84%. The objective of this study was to determine the response of cotton

cultivars to various levels of nitrogen and plant spacing at two sowing dates.

Experimental Design

The experiment was replicated thrice and allocated in a randomized complete block

design with split split plot arrangements with three factors.

NB: This experiment contain two parts i.e each was sown independently on May 10 and

June 01.

Treatments

Nitrogen levels
N1 0
N2 50
N3 100
N4 150
Plant spacings
S1 15 cm
S2 30 cm
Cultivars

C1 CIM-473
C2 CIM-482

83
4.2.1 Materials and Methods

The experiment was conducted to study the response of cotton cultivars to various levels

of nitrogen application and plant spacing. Cotton cultivars CIM-473 and CIM-482 were

planted at May 10 and June 01 on bed furrows 75 cm apart at 15 and 30 cm plant to plant

distance to determine the response of cotton cultivars to various levels of nitrogen and the

appropriate plant spacing. The planting was done manually on bed furrows by dibbling

method. Nitrogen levels were kept in main plots, plant spacing in the sub plots, and

cultivars in the sub sub plots. Nitrogen levels at the rate of 0, 50, 100 and 150 kg ha-1

were applied in three equal split doses on their respective sowing dates i.e. May 10 (June

01, July 05 and August 15), June 01 (June 01,July 05 and August 15). Cultural practices

were adopted as per requirement of the crop. Analytical results of the soil samples

collected at pre planting and after the harvest of crop are given in Table-4.

Table-4 Chemical analysis of the experimental site (2005)

Before sowing After harvesting

Characteristics Depth (cm) Depth (cm)
0-15 15-30 0-15 15-30
-1
EC dSm 2.64 2.72 2.62 2.71
Soil pH (1:1) 8.01 8.09 8.02 8.06
Organic Matter (%) 0.85 0.82 0.86 0.83
-1
NO3-N (mg kg ) 5.52 4.50 5.67 4.63
NaHO3-P (mg kg ) -1
13.7 12.2 12.7 11.6
-1
NH4OAC–K (mg kg ) 124.0 118.0 117.0 107.0

84
2.4.2 Results
Plant height (cm)

Data presented in Table (4.2.1) showed that there were significant difference among

different treatments of cultivars, spacing and nitrogen fertilizer. Cultivar CIM-482

produced significantly taller plants through out the plant growth than CIM-473. It is

evident from the results that at the final harvest (150 DAS) both the cultivars showed a

significant increase in plant height with each level of fertilizer except cultivar CIM-473

tended to produce taller plant with 100 kg nitrogen ha-1 but the differences were not

significant statistically at this level of nitrogen fertilizer. However CIM-482 produced

significantly taller plants with each increment of nitrogen fertilizer than CIM-473. It is

clear from the result that each increment of nitrogen fertilizer showed a significant

increase of plant height on all harvests (50, 100 and 150 DAS) when crop sown early on

May 10, further, narrow spacing (15 cm) treatments significantly produced taller plants

through out the plant growth than wider spacing (30 cm). Similar observation was

observed in case of crop sown late on June 01 in Table (4.2.2) as each level in nitrogen

significantly produced taller plants at all harvests. Further, cultivar CIM-482 produced

significantly taller plants at early and latter stages of growth (50 and 150 DAS), however,

CIM-482 at the harvest of 100 DAS tended to produce taller plants than CIM-473 but the

differences were not significant statistically.

Similarly narrow spacing treatments gave significantly taller plants at early stages of

growth (50 and 100 DAS) and at the final harvest (150 DAS) narrow spacing tended to

produce taller plants than wider spacing treatments but the differences were non

significant statistically when crop sown later on June 01.It is observed from the Table

(4.2.1-2) that crop sown early on May 10 showed comparatively better growth than late

85
sown crop on June 01. All the interactions between nitrogen, cultivar and spacing

treatments were found to be non significant on both the sowing dates.

Table-4.2.1 Effect of cultivars sown on May 10, plant spacing and nitrogen fertilizer
on plant height (cm)
Nitrogen 100 DAS 150 DAS 200 DAS
(kg ha-1) Spacing (cm) Spacing (cm) Spacing (cm)
Cultivars
15 30 Mean 15 30 Mean 15 30 Mean
CIM-473 25.3 24.4 24.9 71.2 69.8 70.5 88.0 85.0 86.5
0 CIM-482 29.0 27.0 28.0 75.5 70.0 72.8 95.0 92.0 93.5
Means 27.2 25.7 26.5 73.4 69.9 71.7 91.5 88.5 90.0
CIM-473 26.3 25.7 26.0 80.0 74.0 77.0 94.0 90.0 92.0
50 CIM-482 31.3 29.6 30.5 80.8 77.5 79.2 105.0 101.0 103.0
Means 28.8 27.7 28.3 80.4 75.8 78.1 99.5 95.5 97.5
CIM-473 30.0 27.7 28.9 82.3 81.5 81.9 97.0 93.0 95.0
100 CIM-482 34.0 31.5 32.8 84.0 81.9 83.0 114.0 111.0 112.5
Means 32.0 29.6 30.8 83.2 81.7 82.5 105.5 102.0 103.8
CIM-473 33.2 29.0 31.1 86.0 84.6 85.3 103.0 98.0 100.5
150 CIM-482 37.3 33.6 35.5 88.6 85.6 87.1 119.0 115.0 117.0
Means 35.3 31.3 33.3 87.3 85.1 86.2 111.0 106.5 108.8
SEs
Nitrogen 0.80 0.43 1.13
Cultivars 0.62 0.30 0.69
Plant spacing 0.92 0.73 1.63
NxC 1.52 1.12 2.57
NxS 1.11 0.79 1.77
CxS 2.18 1.58 3.59
NxCxS 1.18 0.61 1.49
LSD (5%)
Nitrogen 1.95 1.05 2.77
Cultivars 1.43 0.70 1.59
Plant spacing 1.95 1.54 3.46
NxC ns ns ns
NxS ns ns ns
CxS ns ns ns
NxCxS ns ns ns
Sub effects of different variables
Plant height (cm)
Nitrogen Plant
50 100 100 100
levels 150 DAS Cultivars 50 DAS 150 DAS spacing 50 DAS 150 DAS
DAS DAS DAS DAS
(kg ha-1) (cm)
0 26.5c 71.7d 90.0d
CIM-473 27.7b 78.7b 93.5b 15 30.8a 81.1a 101.9a
50 28.3c 78.1c 97.5c
100 30.8b 82.5b 103.8b
CIM-482 31.7a 80.5a 106.5a 30 28.6b 78.1b 98.1b
150 33.3a 86.2a 108.8a

86
Table-4.2.2 Effect of cultivars sown on Jun 01, plant spacing and nitrogen
fertilizer on plant height (cm)
Nitrogen 50 DAS 100 DAS 150 DAS
(kg ha-1) Cultivars Spacing (cm) Spacing (cm) Spacing (cm)
15 30 Mean 15 30 Mean 15 30 Mean
CIM-473 24.0 22.0 23.0 70.0 68.5 69.3 84.0 83.0 83.5
0 CIM-482 27.0 26.0 26.5 74.5 70.0 72.3 94.0 92.0 93.0
Means 25.5 24.0 24.8 72.3 69.3 70.8 89.0 87.5 88.3
CIM-473 25.1 23.0 24.1 76.5 71.5 74.0 90.0 87.0 88.5
50 CIM-482 30.1 28.0 29.1 76.8 74.6 75.7 103.0 100.0 101.5
Means 27.6 25.5 26.6 76.7 73.1 74.9 96.5 93.5 95.0
CIM-473 30.5 27.5 29.0 82.0 79.5 80.8 95.0 93.0 94.0
100 CIM-482 31.3 30.0 30.7 82.0 77.0 79.5 108.0 106.0 107.0
Means 30.9 28.8 29.9 82.0 78.3 80.2 101.5 99.5 100.5
CIM-473 32.5 28.0 30.3 83.0 80.0 81.5 98.0 95.0 96.5
150 CIM-482 35.5 32.4 34.0 84.5 80.5 82.5 115.0 110.0 112.5
Means 34.0 30.2 32.1 83.8 80.3 82.0 106.5 102.5 104.5
SEs
Nitrogen 0.63 0.50 1.82
Cultivars 0.67 0.85 1.37
Plant spacing 1.13 0.60 1.33
NxC 1.46 0.98 2.62
NxS 1.15 1.04 1.91
CxS 0.93 1.77 3.76
NxCxS 2.18 1.30 2.66
LSD (5%)
Nitrogen 1.53 1.23 4.46
Cultivars 1.54 ns 3.17
Plant spacing 1.97 1.27 ns
NxC ns ns ns
NxS ns ns ns
CxS ns ns ns
NxCxS ns ns ns
Sub effects of different variables
Plant height (cm)
Nitrogen
50 100 150 50 100 150 Spacing 50 100 150
levels Cultivars
DAS DAS DAS DAS DAS DAS effects DAS DAS DAS
(kg ha-1)
0 24.8d 70.8d 88.3c
CIM-473 26.6b 76.4b 90.6b 15 29.5a 78.7a 98.4a
50 26.6c 74.9c 95.0b
100 29.9b 80.2b 100.5a
CIM-482 30.1a 77.5a 103.5a 30 27.1b 75.3b 95.8b
150 32.1a 82.0a 104.5a

87
Nodes per plant

Data showed that there were significant difference among different treatments of cultivars,

spacing and nitrogen fertilizer (Table-4.2.3). Cultivars showed a similar trend on both sowing

dates (May 10 and June 01), thus, cultivar CIM-482 showed a higher number of nodes

throughout the plant growth on both sowing dates but significant difference were observed on

early (50 DAS) and late (150 DAS ) growth stages.

Similarly narrow spacing treatments appeared with higher number of nodes through out

the plant growth on both sowing dates and the significant difference were only occurred

at early growth stage (50 DAS) in late sown crop (June 01) treatments. Data showed in

Table (4.2.4) that each increment of nitrogen fertilizer on early growth stage (50 DAS)

tended to gave more nodes and the highest rate of nitrogen fertilizer (150 kg ha-1) gave

significantly (P≤0.05) more number of nodes than other nitrogen rates on early sown crop

(May 10). Similarly at (100 DAS) each nitrogen rate tended to produce more number of

nodes and again the highest rate of nitrogen significantly gave more number of nodes

than lower nitrogen rates (zero and 50 kg ha-1). Again higher rate of nitrogen fertilizer

(100 and 150 kg ha-1) gave significantly more number of nodes than zero nitrogen

treatments. Nearly a similar observation like early sown crop was observed on late sown

crop June 01 for nitrogen treatments.

Thus, at early stage (50 DAS) the higher rate of nitrogen fertilizer (100 and 150 kg ha-1)

gave significantly higher number of nodes than lower rate (zero and 50kg ha-1). However,

at later stages of growth (100 and 150 DAS) 100 and 150 kg ha-1 nitrogen rates gave

significantly more number of nodes than the treatments where zero nitrogen was applied

further, at final harvest (150 DAS) in late sown crop treatments,

88
Table-4.2.3 Effect of cultivars sown on May 10, plant spacing and nitrogen fertilizer
on nodes per plant
Nitrogen 50 DAS 100 DAS 150 DAS
(kg ha-1) Cultivars Spacing (cm) Spacing (cm) Spacing (cm)
15 30 Means 15 30 Means 15 30 Means
CIM-473 14.0 14.0 14.0 26.0 26.0 26.0 31.0 30.0 30.5
0 CIM-482 16.0 15.0 15.5 27.0 26.0 26.5 32.0 32.0 32.0
Means 15.0 14.5 14.8 26.5 26.0 26.3 31.5 31.0 31.3
CIM-473 14.0 14.0 14.0 28.0 27.0 27.5 32.0 31.0 31.5
50 CIM-482 16.0 16.0 16.0 28.0 28.0 28.0 34.0 33.0 33.5
Means 15.0 15.0 15.0 28.0 27.5 27.8 33.0 32.0 32.5
CIM-473 15.0 14.0 14.5 28.0 28.0 28.0 32.0 32.0 32.0
100 CIM-482 17.0 16.0 16.5 28.0 28.0 28.0 36.0 35.0 35.5
Means 16.0 15.0 15.5 28.0 28.0 28.0 34.0 33.5 33.8
CIM-473 16.0 15.0 15.5 29.0 29.0 29.0 33.0 32.0 32.5
150 CIM-482 18.0 17.0 17.5 29.0 29.0 29.0 37.0 36.0 36.5
Means 17.0 16.0 16.5 29.0 29.0 29.0 35.0 34.0 34.5
SEs
Nitrogen 0.39 0.44 0.92
Cultivars 0.38 0.31 0.40
Plant spacing 0.38 0.38 0.58
NxC 0.66 0.69 1.24
NxS 0.53 0.49 0.71
CxS 1.00 0.98 1.59
NxCxS 0.66 0.62 1.08
LSD (5%)
Nitrogen 0.96 1.07 2.25
Cultivars 0.87 ns 0.93
Plant spacing ns ns ns
NxC ns ns ns
NxS ns ns ns
CxS ns ns ns
NxCxS ns ns ns
Sub effects of different variables
Nodes plant-1
Nitrogen
50 100 150 50 100 150 Spacing 50 100 150
levels Cultivars
DAS DAS DAS DAS DAS DAS effects DAS DAS DAS
(kg ha-1)
0 14.8b 26.3c 31.3b
CIM-473 14.7b 27.6 31.6b 15 15.8 27.9 33.4
50 15.0b 27.8b 32.5ab
100 15.5b 28.0ab 33.8a
CIM-482 16.4a 27.9 34.4a 30 15.1 27.6 32.6
150 16.5a 29.0a 34.5a

N: Nitrogen levels C: Cultivars S: Plant spacing

89
Table-4.2.4 Effect of cultivars sown on June 01, plant spacing and nitrogen
fertilizer on nodes per plant
Nitrogen 50 DAS 100 DAS 150 DAS
(kg ha-1) Cultivars Spacing (cm) Spacing (cm) Spacing (cm)
15 30 Means 15 30 Means 15 30 Means
CIM-473 14.0 13.0 13.5 26.0 26.0 26.0 29.0 29.0 29.0
0 CIM-482 15.0 15.0 15.0 27.0 26.0 26.5 30.0 30.0 30.0
Means 14.5 14.0 14.3 26.5 26.0 26.3 29.5 29.5 29.5
CIM-473 14.0 13.0 13.5 27.0 26.0 26.5 29.0 29.0 29.0
50 CIM-482 16.0 16.0 16.0 27.0 27.0 27.0 32.0 32.0 32.0
Means 15.0 14.5 14.8 27.0 26.5 26.8 30.5 30.5 30.5
CIM-473 16.0 15.0 15.5 28.0 28.0 28.0 29.0 29.0 29.0
100 CIM-482 16.0 16.0 16.0 28.0 27.0 27.5 33.0 33.0 33.0
Means 16.0 15.5 15.8 28.0 27.5 27.8 31.0 31.0 31.0
CIM-473 17.0 15.0 16.0 28.0 28.0 28.0 29.0 29.0 29.0
150 CIM-482 18.0 17.0 17.5 28.0 27.0 27.5 35.0 34.0 34.5
Means 17.5 16.0 16.8 28.0 27.5 27.8 32.0 31.5 31.8
SEs
Nitrogen 0.40 0.41 0.37
Cultivars 0.27 0.38 0.34
Plant spacing 0.35 0.31 0.42
NxC 0.64 0.60 0.70
NxS 0.45 0.48 0.54
CxS 0.90 0.91 1.04
NxCxS 0.55 0.67 0.60
LSD (5%)
Nitrogen 0.97 1.01 0.90
Cultivars 0.62 ns 0.78
Plant spacing 0.75 ns ns
NxC ns ns 1.56
NxS ns ns ns
CxS ns ns ns
NxCxS ns ns ns
Sub effects of different variables
Nodes plant-1
Nitrogen
50 100 150 50 100 150 Spacing 50 100 150
levels Cultivars
DAS DAS DAS DAS DAS DAS effects DAS DAS DAS
(kg ha-1)
0 14.3d 26.3b 29.5c
CIM-473 14.6b 27.1 29.0b 15 15.8a 27.4 30.8
50 14.8cd 26.8ab 30.5b
100 15.8b 27.8a 31.0ab
CIM-482 16.1a 27.1 32.4a 30 15.0b 26.9 30.6
150 16.8a 27.8a 31.8a

90
Cultivar CIM-482 produced significantly more number of nodes where nitrogen was

applied at the rate of 50, 100, and 150 kg ha-1 than zero nitrogen treatments. However,

CIM-482 showed significantly more node number than CIM-473 in treatments where

nitrogen was applied at the rate of 50, 100, and 150 kg ha-1.

It is evident from the results that interactions between cultivars and nitrogen fertilizer at

final growth stage (150 DAS) were significant in late sown crop treatments on June 01.

These significant effect might be occurred that nitrogen fertilizer prolonged the

vegetative growth of CIM-482 at final growth stage in late sown crop resulted higher

number of nodes.

Inter-nodal distance cm)

Data presented in Table (4.2.5-6) showed that there were significant differences among

different treatments of cultivars, spacing and nitrogen fertilizer. Cultivar CIM-482

showed a more inter-nodes distance throughout the plant growth on both sowing dates

but significant differences were observed only at final harvest (150 DAS) in early sown

crop on May 10 however, significant differences were also observed at early growth

stages (50 DAS) in late sown crop on June 01. It is observed from the results that spacing

treatments showed a similar trend on both sowing dates (May 10 and June 01). Narrow

spacing (15 cm) treatments showed more inter-nodal distance through out the plant

growth on both sowing dates and the significant differences were occurred at late growth

stages (i.e.100 and 150 DAS) in both sowing dates (May 10 and June 01) treatments.

Data showed that each level of nitrogen fertilizer tended to gave longer inter-nodal

distance on early growth stage (50 DAS) and higher rate of nitrogen (150 and100 kg ha-1)

91
gave significantly more inter-nodal distance than lower rate of nitrogen (50 and zero kg

ha-1) in early sown crop on May 10.

Table-4.2.5 Effect of cultivars sown on May 10, plant spacing and nitrogen fertilizer
on inter-nodal distance (cm)
Nitrogen 50 DAS 100 DAS 150 DAS
(kg ha-1) Cultivars Spacing (cm) Spacing (cm) Spacing (cm)
15 30 Means 15 30 Means 15 30 Means
CIM-473 1.81 1.74 1.78 2.74 2.69 2.72 2.84 2.83 2.84
0 CIM-482 1.81 1.80 1.81 2.80 2.69 2.75 2.97 2.88 2.93
Means 1.81 1.77 1.79 2.77 2.69 2.73 2.91 2.86 2.89
CIM-473 1.88 1.84 1.86 2.86 2.74 2.80 2.94 2.90 2.92
50 CIM-482 1.96 1.85 1.91 2.89 2.77 2.83 3.09 3.06 3.08
Means 1.92 1.85 1.89 2.88 2.76 2.82 3.02 2.98 3.00
CIM-473 2.00 1.98 1.99 2.94 2.91 2.93 3.03 2.91 2.97
100 CIM-482 2.00 1.97 1.99 3.00 2.93 2.97 3.17 3.17 3.17
Means 2.0 198 1.99 2.97 2.92 2.95 3.10 3.04 3.07
CIM-473 2.08 1.94 2.01 2.96 2.92 2.94 3.12 3.06 3.09
150 CIM-482 2.07 1.98 2.03 3.06 2.95 3.01 3.22 3.19 3.21
Means 2.08 1.96 2.02 3.01 2.94 2.98 3.17 3.13 3.15
S.Es
Nitrogen 0.04 0.05 0.07
Cultivars 0.03 0.03 0.04
Plant spacing 0.03 0.02 0.03
NxC 0.06 0.05 0.08
NxS 0.04 0.03 0.05
CxS 0.08 0.07 0.10
NxCxS 0.05 0.06 0.09
LSD (5%)
Nitrogen 0.09 0.11 0.17
Cultivars ns ns 0.09
Plant spacing ns 0.04 0.06
NxC ns ns ns
NxS ns ns ns
CxS ns ns ns
NxCxS ns ns ns
Sub effects of different variables
Inter-nodal distance (cm)
Nitrogen
50 100 150 50 100 150 Spacing 50 100 150
levels Cultivars
DAS DAS DAS DAS DAS DAS effects DAS DAS DAS
(kg ha-1)
0 1.79c 2.73b 2.89b
50 1.89b 2.82b 3.00ab CIM-473 1.91 2.85 3.05 15 1.95 2.91a 3.05
100 1.99a 2.95a 3.07a
150 2.02a 2.98a 3.15a CIM-482 1.94 2.89 3.10 30 1.89 2.83b 3.00

92
Table-4.2.6 Effect of cultivars sown on June 01, plant spacing and nitrogen
fertilizer on inter-nodal distance (cm)
Nitrogen 50 DAS 100 DAS 150 DAS
(kg ha-1) Cultivars Spacing (cm) Spacing (cm) Spacing (cm)
15 30 Mean 15 30 Mean 15 30 Means
CIM-473 1.71 1.69 1.70 2.69 2.63 2.66 2.90 2.86 2.88
0 CIM-482 1.80 1.73 1.77 2.76 2.69 2.73 3.13 3.07 3.10
Means 1.76 1.71 1.74 2.73 2.66 2.70 3.02 2.97 2.99
CIM-473 1.79 1.77 1.78 2.83 2.75 2.79 3.10 3.00 3.05
50 CIM-482 1.88 1.75 1.82 2.84 2.76 2.80 3.22 3.13 3.18
Means 1.84 1.76 1.80 2.84 2.76 2.80 3.16 3.07 3.12
CIM-473 1.91 1.83 1.87 2.93 2.84 2.89 3.28 3.21 3.25
100 CIM-482 1.96 1.88 1.92 2.93 2.85 2.89 3.27 3.21 3.24
Means 1.94 1.86 1.90 2.93 2.85 2.89 3.28 3.21 3.25
CIM-473 1.91 1.87 1.89 2.96 2.86 2.91 3.38 3.28 3.33
150 CIM-482 1.97 1.91 1.94 3.02 2.98 3.00 3.29 3.24 3.27
Means 1.94 1.89 1.92 2.99 2.92 2.96 3.34 3.26 3.30
SEs
Nitrogen 0.03 0.03 0.04
Cultivars 0.03 0.02 0.04
Plant spacing 0.03 0.02 0.03
NxC 0.06 0.05 0.06
NxS 0.04 0.03 0.05
CxS 0.08 0.06 0.09
NxCxS 0.04 0.04 0.07
LSD (5%)
Nitrogen 0.07 0.08 0.11
Cultivars 0.04 ns ns
Plant spacing ns 0.05 0.06
NxC ns ns ns
NxS ns ns ns
CxS ns ns ns
NxCxS ns ns ns
Sub effects of different variables
Inter-nodal distance (cm)
Nitrogen
50 100 150 50 100 Spacing 50 100 150
levels Cultivars 150 DAS
DAS DAS DAS DAS DAS effects DAS DAS DAS
(kg ha-1)
0 1.74b 2.70c 2.99c CIM-473 1.81 2.81a 3.13a 15 1.87b 2.87 3.20
50 1.80b 2.80b 3.12b
100 1.90a 2.89a 3.25a CIM-482 1.86 2.86b 3.20b 30 1.81a 2.80 3.13
150 1.92a 2.96a 3.30a

Similarly, at 100 DAS each nitrogen rate tended to produce more inter-nodal distance and

again the higher rates of nitrogen (100 and 150 kg ha-1) significantly gave more inter-

nodal distance than lower nitrogen rates (zero and 50 kg ha-1) and at 150 DAS, the each

93
nitrogen rate tended to produce more inter-nodal distance and the higher rates of nitrogen

(150 and 100 kg ha-1) gave significantly more inter-nodal distance than zero nitrogen rate

in early sown crop on May 10.

It is evident from the results that all growth stages (50, 100 and 150 DAS) showed a

similar observation in late sown crop. Data showed that each level of nitrogen tended to

gave more inter-nodal distance and the higher nitrogen application at the rate of 50, 100

and 150 kg ha-1 gave significantly more inter-nodal distance than zero nitrogen through

out the growth stages in late sown crop on June 01. However, the interaction of cultivars,

spacing and nitrogen fertilizer were found to be non-significant.

Square initiation (days)

Results showed in Table (4.2.7) that square initiation differed significantly by cultivars,

plant spacing and nitrogen application. Thus, cultivar CIM-473 showed earliness in first

squaring (25.1 DAS) significantly (P≤0.05) than CIM-482 which showed squaring later

(25.7 DAS) in late sown crop. However, the cultivar CIM-473 showed earliness in first

squaring than CIM-482 in early sown crop but the differences were not significant

statistically. It is observed from the results that increase in plant spacing delayed

significantly (P≤0.05) squaring in late sown crop. Similarly in cultivar treatments, early

sown crop again showed to delay squaring but the differences were not significant

statistically. It is evident from the results that each level in nitrogen to both sowing dates

tended to produce significantly (P≤0.05 and 0.01) delayed squaring initiation except with

150 kg nitrogen ha-1 rate that delayed the squaring than 100 kg nitrogen ha-1 but the

differences were not statistically significant.

All other interactions between different treatments of cultivars, plant spacing and

nitrogen levels on both early and late sown crop were found to be non-significant.

94
 Table-4.2.7 Effect of cultivars, plant spacing and nitrogen fertilizer at different
sowing dates on square initiation (days)
Treatments May-10 June-01
Nitrogen Cultivars Plant spacing Plant spacing
(kg ha-1) 15 cm 30 cm Means 15 cm 30 cm Means
CIM-473 25.0 25.0 25.0 23.7 24.3 24.0
0
CIM-482 25.0 25.3 25.2 24.0 24.7 24.4
Means 25.0 25.2 25.1 23.9 24.5 24.2
CIM-473 25.3 26.0 25.7 24.3 25.3 24.8
50
CIM-482 25.7 27.0 26.4 25.0 25.3 25.2
Means 25.5 26.5 26.0 24.7 25.3 25.0
CIM-473 26.3 26.7 26.5 25.3 25.7 25.5
100
CIM-482 27.3 27.3 27.3 26.0 26.3 26.2
Means 26.8 27.0 26.9 25.7 26.0 25.9
CIM-473 26.3 27.0 26.7 26.0 26.3 26.2
150
CIM-482 27.3 27.3 27.3 26.3 27.3 26.8
Means 26.8 27.2 27.0 26.2 26.8 26.5
SEs
Nitrogen 0.25 0.22
Cultivars 0.28 0.21
Plant spacing 0.25 0.26
NxC 0.47 0.37
NxS 0.38 0.33
CxS 0.43 0.43
NxCxS 0.68 0.64
LSD (5%)
Nitrogen 0.61 0.53
Cultivars ns 0.48
Plant spacing ns 0.55
NxC ns ns
NxS ns ns
CxS ns ns
NxCxS ns ns
Sub effects of different variables
May -10 June- 01
Nitrogen Square Square Plant Square Nitrogen Square Square Plant Square
levels initiation Cultivars initiation Spacing initiation levels initiation Cultivars initiation Spacing initiation
(kg ha-1) (days) (days) (cm) (days) (kg ha-1) (days) (days) (cm) (days)
0 25.1c 0 24.2d
CIM-473 26.0 15 26.0 CIM-473 25.1b 15 25.1b
50 26.0b 50 25.0c
100 26.9a 100 25.9b
CIM-482 26.6 30 26.5 CIM-482 25.7a 30 25.7a
150 27.0a 150 26.5a

Flower initiation (days)

Flower initiation cotton crop influenced significantly by the treatments of cultivars and

nitrogen application in Table (4.2.8). Cultivar CIM-473 showed early flower initiation in

95
both the sowing dates (i.e. May 10 and June 01) significantly (P≤0.05) than CIM-482.

However, increase in spacing tended to delay flowering in both the sowing dates but the

differences were not significant statistically.

Table-4.2.8 Effect of cultivars, plant spacing and nitrogen fertilizer at different

sowing dates on flower initiation (days)
Treatments May-10 June-01
Nitrogen Cultivars Plant spacing Plant spacing
(kg ha-1) 15 cm 30 cm Means 15 cm 30 cm Means
CIM-473 44.0 45.0 44.5 44.0 43.7 43.9
0
CIM-482 45.0 45.7 45.4 44.0 45.0 44.5
Means 44.5 45.4 45.0 44.0 44.4 44.2
CIM-473 45.3 46.3 45.8 44.7 45.0 44.9
50
CIM-482 46.0 46.7 46.4 45.3 45.7 45.5
Means 45.7 46.5 46.1 45.0 45.4 45.2
CIM-473 46.0 46.0 46.0 45.3 46.3 45.8
100
CIM-482 47.0 47.0 47.0 46.0 47.3 46.7
Means 46.5 46.5 46.5 45.7 46.8 46.3
CIM-473 46.3 47.3 46.8 46.0 45.7 45.9
150
CIM-482 47.3 48.0 47.7 47.0 47.0 47.0
Means 46.8 47.7 47.3 46.5 46.4 46.5
SEs
Nitrogen 0.42 0.27
Cultivars 0.28 0.26
Plant spacing 0.33 0.35
NxC 0.58 0.46
NxS 0.43 0.44
CxS 0.63 0.57
NxCxS 0.88 0.84
LSD (5%)
Nitrogen 1.04 0.66
Cultivars 0.64 0.61
Plant spacing ns ns
NxC ns ns
NxS ns ns
CxS ns ns
NxCxS ns ns
Sub effects of different variables
May -10 June- 01
Nitrogen Flower Flower Plant Flower Nitrogen Flower Flower Plant Flower
levels initiation Cultivars initiation Spacing initiation levels initiation Cultivars initiation Spacing initiation
(kg ha-1) (days) (days) (cm) (days) (kg ha-1) (days) (days) (cm) (days)
0 45.0c CIM-473 45.8b 15 45.9 0 44.2c CIM-473 45.1b 15 45.3
50 46.1b 50 45.2b
100 46.5ab CIM-482 46.6a 30 46.5 100 46.3a CIM-482 45.9a 30 45.8
150 47.3a 150 46.5a

96
It is observed from the results that each increment of nitrogen tended to delay flower

initiation in both early and late sown crop. However, the all nitrogen levels (i.e.50, 100

and 150 kg nitrogen ha-1) delayed significantly (P≤0.05 and 0.01) the flowering than zero

nitrogen application in early sown crop May 10.While, in the late sown crop June 01 the

higher nitrogen rates (i.e.100 and 150 kg nitrogen ha-1) produced significantly (P≤0.01).

The interactions between cultivars, spacing and nitrogen fertilizer were found to be non

significant on both sowing dates (May 10 and June 01).

Boll split initiation (days)

The results presented in Table (4.2.9) showed that there were significant differences

among different treatments of cultivars, spacing and nitrogen applications. Cultivars

CIM-473 had significantly earlier the boll split initiation than CIM-482 in both the

sowing dates (i.e. May 10 and June 01). It is observed that increase in spacing delayed

significantly (P≤0.01) boll split initiation in early sown crop. However, crop sown in

June 01 again the increase in spacing tended to delay flower initiation but the difference

were not significant statistically. It is evident from the results that crop sown early on

May 01 showed that each level of nitrogen tended to delay boll split initiation however,

the higher nitrogen rates (i.e. 100 and 150 kg ha-1) delayed significantly the boll split

initiation than zero and 50 kg nitrogen ha-1 treatments in early sown crop May 10.While,

in late sown crop each increment in nitrogen fertilizer to delay boll split initiation but the

differences were not significant statistically.

It is observed from the data that interactions of cultivars, plant spacing and nitrogen

fertilizer were found to be non significant on both early as well as late sown crop.

97
Table-4.2.9 Effect of cultivars, plant spacing and nitrogen fertilizer at different
sowing dates on boll spilt initiation (days)
Treatments May-10 June-01
Nitrogen Cultivars Plant spacing Plant spacing
(kg ha-1) 15 cm 30 cm Means 15 cm 30 cm Means
CIM-473 81.0 81.0 81.0 80.0 80.7 80.4
0
CIM-482 81.7 84.0 82.9 82.3 82.0 82.2
Means 81.4 82.5 82.0 81.2 81.4 81.3
CIM-473 81.0 82.3 81.7 80.3 80.7 80.5
50
CIM-482 83.0 84.0 83.5 82.0 83.0 82.5
Means 82.0 83.2 82.6 81.2 81.9 81.5
CIM-473 82.3 83.3 82.8 80.3 81.0 80.7
100
CIM-482 84.0 84.0 84.0 83.3 84.0 83.7
Means 83.2 83.7 83.4 81.8 82.5 82.2
CIM-473 82.3 83.0 82.7 81.3 81.0 81.2
150
CIM-482 84.0 85.0 84.5 83.3 84.0 83.7
Means 83.2 84.0 83.6 82.3 82.5 82.4
SEs
Nitrogen 0.29 0.48
Cultivars 0.27 0.33
Plant spacing 0.32 0.30
NxC 0.48 0.67
NxS 0.42 0.45
CxS 0.54 0.64
NxCxS 0.81 0.90
LSD (5%)
Nitrogen 0.71 ns
Cultivars 0.63 0.77
Plant spacing 0.68 ns
NxC ns ns
NxS ns ns
CxS ns ns
NxCxS ns ns
Sub effects of different variables
May -10 June- 01
Nitrogen Boll split Boll split Plant Boll split Nitrogen Boll split Boll split Plant Boll split
levels initiation Cultivars initiation Spacing initiation levels initiation Cultivars initiation Spacing initiation
(kg ha-1) (days) (days) (cm) (days) (kg ha-1) (days) (days) (cm) (days)
0 82.0bc CIM-473 82.1b 15 82.5b 0 81.3 CIM-473 80.7b 15 81.6
50 82.6b 50 81.5
100 83.4a CIM-482 83.7a 30 83.4a 100 82.2 CIM-482 83.0a 30 82.1
150 83.6a 150 82.4

98
Number of bolls m-2

The results showed that there were significant differences among different treatments of

cultivars, plant spacing and nitrogen application (Table-4.2.10) for bolls per m-2.

However, cultivar CIM-473 produced significantly (P≤0.01) more bolls per m-2 than

cultivar CIM-482 on both sowing dates (i.e. May 10 and June 01). It is obvious from the

results that crop sown early on May 10 gave significantly (P≤0.01) more boll number

than sown late on June 01. Results also showed that maximum bolls (P≤0.01) were

produced with narrow spacing (15 cm) on both early and late sown crops. Nitrogen

fertilizer application influenced significantly the number of bolls per m-2 and further,

each level of nitrogen fertilizer increased significantly (P≤0.01) the bolls number on early

as well as late sown crops. However, the more bolls number (123 m-2) were produced

with the highest nitrogen rate (150 kg ha-1) and the lowest number of 68 m-2 were

observed with zero nitrogen treatments on early sown crop (May 10).Similarly late sown

crop produced the maximum bolls (116 m-2) with 150 kg nitrogen ha-1 treatment and

minimum bolls number (63 m-2) were produced with zero nitrogen application. It is also

observed that increase in nitrogen produced significantly higher bolls m-2 with narrow

spacings treatments.

It is evident from the data that interactions between nitrogen fertilizer and plant spacing

treatments on both sowing dates were found to be significant (Fig.4.2.2-3) this significant

affect might be occurred due to the maximum number of plants in narrow spacings

treatments that resulted significantly the more number of bolls m-2 with each increase of

nitrogen fertilizer.

99
Table-4.2.10 Effect of cultivars, plant spacing and nitrogen fertilizer at different
sowing dates on bolls per m-2
Treatments May-10 June-01
Nitrogen Cultivars Plant spacing Plant spacing
(kg ha-1) 15 cm 30 cm Means 15 cm 30 cm Means
CIM-473 74 68 71 70 61 66
0
CIM-482 70 58 64 65 54 60
Means 72 63 68 68 58 63
CIM-473 114 104 109 108 99 104
50
CIM-482 105 90 98 100 86 93
Means 110 97 104 104 93 99
CIM-473 126 116 121 120 108 114
100
CIM-482 120 99 110 111 98 105
Means 123 108 116 116 103 110
CIM-473 135 125 130 126 118 122
150
CIM-482 123 106 115 117 100 109
Means 129 116 123 122 109 116
SEs
Nitrogen 0.67 1.90
Cultivars 0.95 1.27
Plant spacing 1.69 2.18
NxC 1.50 2.56
NxS 2.84 4.00
CxS 2.17 2.82
NxCxS 4.18 5.66
LSD (5%)
Nitrogen 1.63 4.46
Cultivars 2.20 2.94
Plant spacing 3.44 4.45
NxC ns ns
NxS 5.85 8.91
CxS 4.54 5.92
NxCxS ns ns
Sub effects of different variables
May -10 June- 01
Nitrogen Plant Nitrogen Plant
Bolls Bolls Bolls Bolls Bolls Bolls
levels Cultivars Spacing levels Cultivars Spacing
m-2 m-2 m-2 m-2 m-2 m-2
(kg ha-1) (cm) (kg ha-1) (cm)
0 68.0d CIM-473 107.8a 15 108.5a 0 63.0d CIM-473 101.5a 15 102.5a
50 104.0c 50 99.0c
100 116.0b CIM-482 96.8b 30 96.0b 100 110.0b CIM-482 91.8b 30 90.8b
150 123.0a 150 116.0a

100
 May-10
120

100

80

Bolls m-2 60

40

20

0
15cm 30cm
Plant spacing (cm)

CIM-473 CIM-482

Fig.4.2.1 Interactive effect of spacing and cultivars on bolls m-2

May-10

140

120
Bolls m-2

100

80

60

40
0 50 100 150
-1
Nitrogen levels (kg ha )

15cm 30cm

Fig.4.2.2. Interactive effect of nitrogen and spacing bolls m-2

101
 June-01

130
120
110
100

-2
90
Bolls m 80
70
60
50
40
0 50 100 150
-1
Nitrogen levels (kg ha )

15cm 30cm

Fig.4.2.3 Interactive effect of nitrogen and spacing on bolls m-2

June-01
120

100

80
-2
Bolls m

60

40

20

0
15cm 30cm
Plant spacing (cm)

CIM-473 CIM-482

Fig.4.2.4 Interactive effect of cultivar and spacing bolls m-2

The interactions between cultivars and spacings were also found to be significant (Fig-

4.2.1 & 4) on both sowing dates (i.e. May 10 and June 01). Again, this significant affect

was occurred because both the cultivars produced higher number of bolls with narrow

102
spacings. Other interactions of cultivars, spacings and nitrogen fertilizer treatments were

found to be non- significant.

Boll weight (g)

Results relating to boll weight indicated that cultivars and plant spacings influenced

significantly the boll weight of cotton crop (Table-4.2.11). Cultivar CIM-482 gave

significantly (P≤0.01) higher boll weight than CIM-473 on early as well as late sown

crops. Data indicated that late sown crop on June 01 produced significantly (P≤0.05)

higher boll weight than early sown crop on May 10. Plant spacing treatments showed that

30 cm spacing produced significantly higher boll weight than narrow spacing (15 cm) on

both sowing dates (May 10 and June 01). It is observed from the data that nitrogen

fertilizer influenced significantly the boll weight in early sown crop (May 10).The lower

rate of nitrogen application (50 kg ha-1) increased the boll weight but not significantly,

however beyond this rate each increment of nitrogen increased significantly (P≤0.05) the

boll weight in early sown crop on May 10. In late sown treatments on June 01, nitrogen

fertilizer tended to increase boll weight with each level but statistically differences were

not significant.

It is observed from the data that interactions of cultivars, spacing and nitrogen fertilizer

were found to be non-significant on both early as well as late sown crops.

103
Table-4.2.11 Effects of cultivars, plant spacing and nitrogen fertilizer at different
sowing dates on boll weight (g)
Treatments May-10 June-01
Nitrogen Cultivars Plant spacing Plant spacing
(kg ha-1) 15 cm 30 cm Means 15 cm 30 cm Means
CIM-473 2.36 2.40 2.38 2.40 2.45 2.43
0
CIM-482 2.40 2.57 2.49 2.43 2.61 2.52
Means 2.38 2.49 2.44 2.42 2.53 2.48
CIM-473 2.38 2.44 2.41 2.41 2.48 2.45
50
CIM-482 2.44 2.58 2.50 2.45 2.64 2.55
Means 2.41 2.51 2.46 2.43 2.56 2.50
CIM-473 2.42 2.47 2.45 2.49 2.54 2.47
100
CIM-482 2.46 2.63 2.55 2.53 2.74 2.64
Means 2.44 2.55 2.50 2.51 2.64 2.56
CIM-473 2.46 2.50 2.48 2.52 2.56 2.53
150
CIM-482 2.53 2.67 2.60 2.55 2.78 2.67
Means 2.50 2.59 2.54 2.54 2.67 2.60
SEs
Nitrogen 0.02 0.05
Cultivars 0.01 0.03
Plant spacing 0.03 0.04
NxC 0.02 0.06
NxS 0.05 0.07
CxS 0.06 0.04
NxCxS 0.07 0.10
LSD (5%)
Nitrogen 0.04 ns
Cultivars 0.03 0.06
Plant spacing 0.07 0.08
NxC ns ns
NxS ns ns
CxS ns ns
NxCxS ns ns
Sub effects of different variables
May -10 June- 01
Nitrogen Boll Boll Plant Boll Nitrogen Boll Boll Plant Boll
levels weight Cultivars weight Spacing weight levels weight Cultivars weight Spacing weight
(kg ha-1) gm) (gm) (cm) (gm) (kg ha-1) (gm) (gm) (cm) (gm)
0 2.44c CIM-473 2.43a 15 2.43b 0 2.48 CIM-473 2.47b 15 2.48b
50 2.46c 50 2.50
100 2.50b CIM-482 2.54b 30 2.54a 100 2.56 CIM-482 2.60a 30 2.60a
150 2.54a 150 2.60

104
Seed cotton yield (kg ha-1)

Seed cotton yield of cotton cultivars influenced significantly by the treatments of

spacings and nitrogen application (Table-4.2.12). Results showed that cultivar CIM-473

produced significantly (P≤0.01) higher seed cotton yield than cultivar CIM-482 on both

sowing dates (i.e. May 10 and June 01). It is evident from the data that crop sown early

on May 10 gave significantly (P≤0.01) higher seed cotton yield than crop sown late on

June 01. Results also showed that significantly (P≤0.01) higher cotton yield was observed

with narrow spacing (15 cm) on both early and late sown crops.

However, it is observed that both cultivars gave significantly higher yield with narrow

spacing treatments on early as well as late sown crops. Data showed that nitrogen

application influenced significantly the seed cotton yield and each increment of nitrogen

fertilizer increased significantly (P≤0.01) the cotton yield, on both early and late sown

crops. Thus, the highest yield of 2849.0 kg ha-1 was produced with the highest nitrogen

rate (150 kg ha-1) and the lowest (1404 kg ha-1) seed cotton yield was observed with zero

nitrogen application on early sown crop (May 10), similarly late sown crop showed the

highest yield of 2762.0 kg ha-1 with 150 kg nitrogen ha-1 rate and the lowest yield of

1313.0 kg ha-1 with zero nitrogen fertilizer. It is observed that each increment in nitrogen

application produced significantly higher seed cotton yield with narrow spacing

treatments on early sown crop (May 10) however, in late sown crop, each increase in

nitrogen fertilizer tended to produce higher yield with narrow spacing but, statistically,

significant differences were observed with 50 and 100 kg nitrogen ha-1 treatments.

It is evident from the results that interactions between nitrogen fertilizer and plant

spacing treatments on both sowing dates were found to be significant (Fig-4.2.6).

105
 Table-4.2.12 Effect of cultivars, plant spacing and nitrogen fertilizer at different
sowing dates on seed cotton yield (kg ha-1)
Treatments May-10 June-01
Nitrogen Plant spacing Plant spacing
Cultivars
(kg ha-1) 15 cm 30 cm Means 15 cm 30 cm Means
CIM-473 1568 1373 1471 1453 1273 1363
0
CIM-482 1438 1233 1336 1359 1164 1262
Means 1503 1303 1404 1406 1219 1313
CIM-473 2457 2299 2378 2322 2153 2238
50
CIM-482 2288 2076 2182 2182 1842 2012
Means 2373 2188 2280 2252 1998 2125
CIM-473 2826 2596 2711 2781 2512 2647
100
CIM-482 2737 2367 2552 2601 2312 2457
Means 2782 2482 2632 2691 2412 2552
CIM-473 3092 2878 2985 2960 2781 2871
150
CIM-482 2856 2569 2713 2760 2543 2652
Means 2974 2724 2849 2860 2662 2762
SEs
Nitrogen 13.16 46.34
Cultivars 17.45 26.71
Plant spacing 40.00 52.70
NxC 27.96 62.55
NxS 66.64 97.73
CxS 49.38 67.71
NxCxS 96.53 136.83
LSD (5%)
Nitrogen 32.24 113.53
Cultivars 40.30 68.62
Plant spacing 81.61 107.50
NxC ns ns
NxS 137.01 208.39
CxS 102.40 ns
NxCxS ns ns
Sub effects of different variables
May -10 June- 01
Seed Seed Seed Seed Seed Seed
Nitrogen Plant Nitrogen Plant
cotton cotton cotton cotton cotton cotton
levels Cultivars Spacing levels Cultivars Spacing
yield yield yield yield yield yield
(kg ha-1) (cm) (kg ha-1) (cm)
(kg ha-1) (kg ha-1) (kg ha-1) (kg ha-1) (kg ha-1) (kg ha-1)
0 1404d CIM-473 2386a 15 2408a 0 1313d CIM-473 2280a 15 2302a
50 2280c 50 2125c
100 2632b CIM-482 2196b 30 2174b 100 2552b CIM-482 2096b 30 2073b
150 2849a 150 2762a

106
 2600 May-10

Seed cotton yield (kg ha )

2400
-1

2200

2000

1800
15cm 30cm
Plant spacing (cm)

CIM-473 CIM-482

Fig.4.2.5. Interactive effect of spacing and cultivars on seed cotton yield (kg ha-1)

June-01

3000
Seed cotton yield (kg ha )
-1

2500

2000

1500

1000

500
0 50 100 150
-1
Nitrogen levels (kg ha )

15cm 30cm

Fig.4.2.6 Interactive effect of nitrogen and spacing on seed cotton yield (kg ha-1)

107
This significant effect might be occurred due to higher number of plants in narrow

spacing treatments that resulted in significantly higher seed cotton yield with each level

of nitrogen fertilizer. Similarly, the interactions between cultivars and spacings were also

found to be significant on early sown crop (Fig.4.2.5) again this significant affect was

occurred because both the cultivars produced higher yield with narrow spacing due to

higher number of plants in narrow spacing treatments. However, other interactions

between cultivars, spacings and nitrogen fertilizer treatments were found to be non-

significant.

Ginning out turn percentage (%)

Data on ginning out turn percentage (GOT %) showed that different treatments of

cultivars influenced significantly the GOT percentage (Table-4.2.13). Thus, cultivar

CIM-473 produced significantly (P≤0.01) the higher GOT percentage than CIM-482 on

both the sowing dates. However, GOT percentage was not influenced by the treatments

of nitrogen fertilizer and spacing.

Further, interactions of all these treatments were also found to be non-significant.

108
Table-4.2.13 Effect of cultivars, plant spacing and nitrogen fertilizer at
different sowing dates on ginning out turn percentage
Treatments May-10 June-01
Nitrogen Plant spacing Plant spacing
Cultivars
(kg ha-1) 15 cm 30 cm Means 15 cm 30 cm Means
CIM-473 41.3 41.7 41.5 41.4 42.4 41.9
0
CIM-482 40.8 41.2 41.0 40.8 39.5 40.2
Means 41.1 41.5 41.3 41.1 41.0 41.1
CIM-473 41.4 42.3 41.9 41.2 41.9 41.6
50
CIM-482 40.3 39.5 39.9 40.2 40.5 40.4
Means 40.9 40.9 40.9 40.7 41.2 41.0
CIM-473 42.4 42.8 42.6 42.2 41.7 42.0
100
CIM-482 40.4 40.3 40.4 41.2 40.4 40.8
Means 41.4 41.6 41.5 41.7 41.1 41.4
CIM-473 42.8 42.2 42.5 42.0 42.0 42.0
150
CIM-482 40.1 40.2 40.2 41.2 39.8 40.5
Means 41.5 41.2 41.4 41.6 40.9 41.3
SEs
Nitrogen 0.40 0.53
Cultivars 0.27 0.15
Plant spacing 0.27 0.20
NxC 0.53 0.57
NxS 0.53 0.61
CxS 0.38 0.25
NxCxS 0.75 0.70
LSD (5%)
Nitrogen ns ns
Cultivars 0.63 0.34
Plant spacing ns ns
NxC ns ns
NxS ns ns
CxS ns ns
NxCxS ns ns
Sub effects of different variables
May -10 June- 01
Nitrogen Plant Nitrogen Plant
G.O.T G.O.T G.O.T G.O.T G.O.T G.O.T
levels Cultivars Spacing levels Cultivars Spacing
(%age) (%age) (%age) (%age) (%age) (%age)
(kg ha-1) (cm) (kg ha-1) (cm)
0 41.3 CIM-473 42.1a 15 41.2 0 41.1 CIM-473 41.9a 15 41.3
50 40.9 50 41.0
100 41.5 CIM-482 40.4b 30 41.3 100 41.4 CIM-482 40.5b 30 41.1
150 41.4 150 41.3

Seed index (g)

Table (4.2.14) showed a similar observation like that of GOT percentage and

significantly higher seed index was observed with cultivar CIM-482

109
 Table-4.2.14 Effect of cultivars, plant spacing and nitrogen fertilizer at different
sowing dates on seed index (g)
Treatments May-10 June-01
Nitrogen Cultivars Plant spacing Plant spacing
(kg ha-1) 15 cm 30 cm Means 15 cm 30 cm Means
CIM-473 8.4 8.7 8.6 8.7 8.3 8.5
0
CIM-482 8.9 9.2 9.1 9.0 8.9 9.0
Means 8.7 9.0 8.9 8.9 8.6 8.8
CIM-473 9.1 8.6 8.9 8.9 8.5 8.7
50
CIM-482 9.2 9.3 9.3 9.0 9.3 9.2
Means 9.2 9.0 9.1 9.0 8.9 9.0
CIM-473 8.4 8.2 8.3 8.6 8.7 8.7
100
CIM-482 8.7 8.9 8.8 8.7 8.8 8.8
Means 8.6 8.6 8.6 8.7 8.8 8.8
CIM-473 8.4 8.4 8.4 8.2 8.3 8.3
150
CIM-482 9.2 9.4 9.3 9.2 9.4 9.3
Means 8.8 8.9 8.9 8.7 8.9 8.8
SEs
Nitrogen 0.16 0.15
Cultivars 0.14 0.03
Plant spacing 0.10 0.07
NxC 0.25 0.16
NxS 0.21 0.18
CxS 0.17 0.08
NxCxS 0.32 0.21
LSD (5%)
Nitrogen ns ns
Cultivars 0.31 0.08
Plant spacing ns ns
NxC ns 0.39
NxS ns ns
CxS ns ns
NxCxS ns ns
Sub effects of different variables
May -10 June- 01
Nitrogen Seed Seed Plant Seed Nitrogen Seed Seed Plant Seed
levels index Cultivars index Spacing index levels index Cultivars index Spacing index
(kg ha-1) (g) (g) (cm) (g) (kg ha-1) (g) (g) (cm) (g)
0 8.9 CIM-473 8.6b 15 8.8 0 8.8 CIM-473 8.6b 15 8.8
50 9.1 50 9.0
100 8.6 CIM-482 9.1a 30 8.9 100 8.8 CIM-482 9.1a 30 8.8
150 8.9 150 8.8

While, lower seed index was observed with CIM-473 on both sowing dates. However,

cultivar CIM-482 produced significantly (P≤0.05) the higher seed index than CIM-473

on both the sowing dates. Data showed that different treatments of nitrogen fertilizer and

spacing on average basis did not affect the seed index significantly. However, nitrogen

110
application gave better response to seed index with cultivar CIM-482 when sown early on

May 10 but, this response was not statistically significant.

It is evident from the results that interactions between nitrogen fertilizers and cultivars

were found to be significant with early sown crop. This significant effect might be

occurred because of better response of cultivar CIM-482 to nitrogen fertilizer when sown

early on May 10. Other interactions of cultivars, spacing, nitrogen fertilizer and sowing

dates were found to be non-significant.

Total fruiting points m-2

Data presented in (Table-4.2.15-16) showed that there were significant difference among

different treatments of cultivars, spacing and nitrogen fertilizer. Cultivar CIM-482

produced significantly (P≤0.05) more total fruiting points than CIM-473 at all growth

stages (i-e 50,100 and 150 DAS) in both sowing dates. It is also evident from the results

that each dose of nitrogen tended to produce significantly more total fruiting points at all

growth stages in early and late sown crops. It is observed from the results that 15 cm

produced significantly higher (P≤0.05) number of total fruiting points through out growth

season in both sowings. However at early growth stage (50 days) in both sowing dates all

factors did not show any significant interaction with each other. Cultivar CIM-482

responded more favorably to nitrogen fertilizer at later stages of growth (i.e. 100 and 150

DAS) in both sowing and produced significantly (P≤0.05) more number of total fruiting

points than CIM-473 at each incremental dose of nitrogen fertilizer. Results also depicted

that at the final harvest (150 DAS) both the cultivars produced more total fruiting points

with 15cm spacing in each nitrogen fertilizer levels at both sowing dates. Narrow spacing

treatments produced comparatively more total fruiting points with nitrogen increments at

100 and 150 days in early and late sown crop. Furthermore, it was observed that early

111
crop sowing of May 10 tended to produce more number of total fruiting points in all

treatments and their interactions (Fig. 4.2.7).

Table-4.2.15 Effect of cultivars sown on May 10, plant spacing and nitrogen
fertilizer on total fruiting points m-2
Nitrogen 50 DAS 100 DAS 150 DAS
(kg ha-1) Cultivars Spacing (cm) Spacing (cm) Spacing (cm)
15 30 Means 15 30 Means 15 30 Means
CIM-473 78.4 65.0 71.7 288 195 241.5 382 285 333.5
0 CIM-482 80.4 66.0 73.2 305 208 256.5 416 295 355.5
Means 79.4 65.5 72.5 296.5 201.5 249.0 399.0 290.0 344.5
CIM-473 83.0 73.0 78.0 352 260 306.0 460 340 400.0
50 CIM-482 85.1 74.0 79.6 355 261 308.0 470 340 405.0
Means 84.1 73.5 78.8 353.5 260.5 307.0 465.0 340.0 402.5
CIM-473 91.0 78.0 84.5 370 272 321.0 475 345 410.0
100 CIM-482 92.4 78.5 85.5 376 272 324.0 480 350 415.0
Means 91.7 78.3 85.0 373.0 272.0 322.5 477.5 347.5 412.5
CIM-473 93.0 80.3 86.7 390 286 338.0 490 370 430.0
150 CIM-482 95.0 84.2 89.6 394 289 341.5 495 370 432.5
Means 94.0 82.3 88.2 392.0 287.5 339.8 492.5 370.0 431.3
S.Es
Nitrogen 0.94 0.65 0.93
Cultivars 0.69 0.86 0.87
Plant spacing 0.91 1.21 1.33
NxC 3.22 1.38 1.54
NxS 3.57 1.83 2.10
CxS 2.51 1.49 1.59
NxCxS 2.28 2.79 3.08
LSD (5%)
Nitrogen 2.29 1.59 2.28
Cultivars 1.60 1.99 2.01
Plant spacing 1.94 2.57 2.82
NxC ns 3.23 3.64
NxS ns 3.96 4.59
CxS ns ns 3.46
NxCxS ns ns 6.71
Sub effects of different variables
Fruiting points m-2
Nitrogen Plant
50 100 150 50 100 150 50 100 150
levels Cultivars Spacing
DAS DAS DAS DAS DAS DAS DAS DAS DAS
(kg ha-1) (cm)
0 72.5d 249.3d 344.5d CIM-473 80.2b 301.6b 393.4b 15 87.3a 353.9a 458.5a
50 78.8c 302.0c 402.5c
100 85.0b 322.5b 412.5b CIM-482 82.0a 307.5a 402.0a 30 74.9b 255.4b 336.9b
150 88.2a 333.8a 431.3a

112
Table-4.2.16 Effect of cultivars sown on June 01, plant spacing and nitrogen
fertilizer on total fruiting points m-2
Nitrogen 50 DAS 100 DAS 150 DAS
(kg ha-1) Cultivars Spacing (cm) Spacing (cm) Spacing (cm)
15 30 Means 15 30 Means 15 30 Means
CIM-473 75.6 62.8 69.2 255 188 221.5 371 260 315.5
0 CIM-482 78.0 66.1 72.1 270 192 231.0 390 260 325.0
Means 76.8 64.5 70.7 262.5 190.0 226.3 380.5 260.0 320.3
CIM-473 82.0 72.0 77.0 338 252 295.0 440 325 382.5
50 CIM-482 84.0 72.0 78.0 339 255 297.0 455 318 386.5
Means 83.0 72.0 77.5 338.5 253.5 296.0 447.5 321.5 384.5
CIM-473 89.0 76.0 82.5 352 258 305.0 470 334 402.0
100 CIM-482 90.8 77.3 84.1 355 261 308.0 472 330 401.0
Means 89.9 76.7 83.3 353.5 259.5 306.5 471.0 332.0 401.5
CIM-473 91.0 79.2 85.1 370 266 318.0 487 344 415.5
150 CIM-482 94.0 82.8 88.4 381 276 328.5 492 352 422.0
Means 92.5 81.0 86.8 375.5 271.0 323.3 489.5 348.0 418.8
SEs
Nitrogen 0.84 1.10 0.76
Cultivars 0.43 0.77 1.11
Plant spacing 1.23 1.18 1.21
NxC 1.03 1.54 1.74
NxS 1.93 2.00 1.88
CxS 1.30 1.41 1.64
NxCxS 2.66 2.82 2.99
LSD (5%)
Nitrogen 2.05 2.69 1.86
Cultivars 0.98 1.77 2.56
Plant spacing 2.60 2.50 2.57
NxC ns 3.68 ns
NxS ns 4.43 4.08
CxS ns ns 3.63
NxCxS ns ns 6.55
Sub effects of different variables
Fruiting points m-2
Nitrogen 50 100 150 Cultivars 50 100 150 Plant 50 100 150
levels DAS DAS DAS DAS DAS DAS Spacing DAS DAS DAS
(kg ha-1) (cm)
0 70.7d 226.3d 320.3d CIM-473 78.5b 284.9b 378.9b 15 85.6a 284.9a 378.9a
50 77.5c 296.0c 384.5c
100 83.3b 306.5b 401.5b CIM-482 80.7a 291.1a 383.6a 30 73.6b 291.1b 383.6b
150 86.8a 323.3a 418.8a

113
 450
May 10
400

350

Frutiting points m 100 DAS

300

250
-2

200

150

100

50

0
0 50 100 150
-1
Nitrogen levels (kg ha )

15cm 30cm

Fig. 4.2.7 Interactive effect of nitrogen and plant spacing on total fruiting points
at 100 DAS

Total intact fruits m-2

Data showed that there was significant difference among different treatments of cultivars,

spacing and nitrogen fertilizer (Table-4.2.17-18 May 10 and June 01). Cultivars showed a

similar trend on both sowing dates (May 10 and June 01), However, cultivar CIM-473

produced higher number of intact fruits throughout the plant growth on both sowing dates but

significant differences (P≤0.01) were observed at later growth stages (100 and 150 days).

Similarly narrow spacing treatments showed more number of intact fruits per unit area

throughout the cropping season in both sowing dates and the significant differences (P≤0.01)

were observed at all growth stages (i-e 50,100 and 150) in both sowing dates. In early sowing

date cultivar CIM-473 produced significantly higher intact fruits per unit area as compared to

CIM-482 at later growth stages. Whereas, the differences at early growth stages (50 DAS) of

the crop were found to be non-significant. It was observed from the results that each increment

of nitrogen fertilizer on all growth stages produced more number of intact fruits and highest

rate of nitrogen fertilizer (150 kg ha-1) produced significantly (P≤0.01) more number of intact

fruits than other nitrogen rates in early and late sown crop (May 10 and June 01). In early sown

114
crop among the cultivars CIM-473 showed better response to the nitrogen treatments, it was

observed that CIM-473 produced significantly (P≤0.05) more intact fruits with each increment

of nitrogen dose at 100 and 150 days showing a significant nitrogen x cultivars interaction at

later growth stages of crop. However, in late sown crop nitrogen x cultivar interaction was only

significant at 100 days after sowing.

Table-4.2.17 Effect of cultivars sown on May 10, plant spacing and nitrogen
fertilizer on intact fruits m-2
Nitrogen 50 DAS 100 DAS 150 DAS
(kg ha-1) Cultivar Spacing (cm) Spacing (cm) Spacing (cm)
15 30 Mea ns 15 30 Means 15 30 Means
CIM-473 55.0 46.0 50.5 116.0 85.0 100.5 127.0 96.0 111.5
0 CIM-482 54.8 45.9 50.4 112.0 82.0 97.0 118.0 92.0 105.0
Means 54.9 46.0 50.5 114.0 83.5 98.8 122.5 94.0 108.3
CIM-473 58.6 51.7 55.2 147.0 115.0 131.0 160.0 124.0 142.0
50 CIM-482 58.0 52.0 55.0 134.0 104.0 119.0 140.0 110.0 125.0
Means 58.3 51.9 55.1 140.5 109.5 125.0 150.0 117.0 133.5
CIM-473 66.0 56.9 61.5 168.0 124.0 146.0 175.0 130.0 152.5
100 CIM-482 64.8 55.7 60.3 146.0 109.0 127.5 155.0 118.0 136.5
Means 65.4 56.3 60.9 157.0 116.5 136.8 165.0 124.0 144.5
CIM-473 69.0 60.2 64.6 180.0 134.0 157.0 186.0 142.0 164.0
150 CIM-482 68.2 60.0 64.1 158.0 122.0 140.0 166.0 126.0 146.0
Means 68.6 60.1 64.4 169.0 128.0 148.5 176.0 134.0 155.0
SEs
Nitrogen 0.54 0.99 0.71
Cultivars 0.59 0.78 0.70
Plant spacing 1.02 1.44 1.15
NxC 0.99 1.49 1.22
NxS 1.54 2.28 1.77
CxS 1.18 1.64 1.34
NxCxS 2.27 3.24 2.60
LSD (5%)
Nitrogen 1.31 2.43 1.75
Cultivars ns 1.81 1.62
Plant spacing 2.16 3.06 2.43
NxC ns 3.53 2.88
NxS ns 4.95 3.86
CxS ns ns 2.92
NxCxS ns ns Ns
Sub effects of different variables
Intact fruits (m-2)
Nitrogen Plant
50 100 150 50 100 150 50 100 150
levels Cultivars Spacing
DAS DAS DAS DAS DAS DAS DAS DAS DAS
(kg ha-1) (cm)
0 50.5d 98.8d 108.3d CIM-473 58.0 133.6a 412.5a 15 61.8a 145.1a 153.4a
50 55.1c 125.0c 133.5c
100 60.9b 136.8b 144.5b CIM-482 57.5 120.9b 128.1b 30 53.6b 109.4b 117.3b
150 64.4a 148.5a 155.0a

115
Table-4.2.18 Effect of cultivars sown on June 01, plant spacing and nitrogen
fertilizer on intact fruits m-2
Nitrogen 50 DAS 100 DAS 150 DAS
(kg ha-1) Cultivars Spacing (cm) Spacing (cm) Spacing (cm)
15 30 Means 15 30 Means 15 30 Means
CIM-473 52.0 44.3 48.2 102.0 80.0 91.0 110.0 85.0 97.5
0 CIM-482 52.0 45.6 48.8 96.0 74.0 85.0 104.0 80.0 92.0
Means 52.0 45.0 48.5 99.0 77.0 88.0 107.0 82.5 94.8
CIM-473 56.7 51.0 53.9 138.0 109.0 123.5 142.0 114.0 128.0
50 CIM-482 56.8 50.0 53.4 127.0 99.0 113.0 133.0 101.0 117.0
Means 56.8 50.5 53.7 132.5 104.0 118.3 137.5 107.5 122.5
CIM-473 64.0 55.1 59.6 156.0 115.0 135.5 160.0 118.0 139.0
100 CIM-482 63.4 54.7 59.1 136.0 103.0 119.5 148.0 110.0 129.0
Means 63.7 54.9 59.4 146.0 109.0 127.5 154.0 114.0 134.0
CIM-473 67.0 58.9 63.0 168.0 123.0 145.5 173.0 125.0 149.0
150 CIM-482 66.2 58.5 62.4 149.0 110.0 129.5 159.0 118.0 138.5
Means 66.6 58.7 62.7 158.5 116.5 137.5 166.0 121.5 143.8
SEs
Nitrogen 0.62 1.01 1.32
Cultivars 0.41 1.18 0.99
Plant spacing 1.05 1.21 1.13
NxC 0.85 1.95 1.93
NxS 1.61 1.98 2.08
CxS 1.12 1.69 1.50
NxCxS 2.26 3.10 2.97
LSD (5%)
Nitrogen 1.53 2.47 3.24
Cultivars ns 2.72 2.29
Plant spacing 2.22 2.56 2.39
NxC ns 4.58 ns
NxS ns 4.37 4.68
CxS ns ns ns
NxCxS ns ns ns
Sub effects of different variables
Intact fruits (m-2)
Nitrogen Plant
50 100 150 50 100 150 50 100 150
levels Cultivars Spacing
DAS DAS DAS DAS DAS DAS DAS DAS DAS
(kg ha-1) (cm)
0 48.5d 88.0d 94.8d CIM-473 56.2 123.9a 128.4a 15 59.8a 134.0a 141.1a
50 53.7c 118.3c 122.5c
100 59.4b 127.5b 134.0b CIM-482 55.9 111.8b 119.1b 30 52.3b 101.6b 106.4b
150 62.7a 137.5a 143.8a

116
 180
May 10
160

140

Intact fruits m 100 DAS

120

100
-2

80

60

40

20

0
0 50 100 150
-1
Nitrogen levels (kg ha )

15cm 30cm

Fig.4.2.8 Interactive effect of nitrogen and plant spacing on intact fruits m-2at 100
DAS

200
May 10
180
160
Intact fruits m 150 DAS

140
120
-2

100
80
60
40
20
0
0 50 100 150
-1
Nitrogen levels (kg ha )

15cm 30cm

Fig.4.2 9. Interactive effect of nitrogen and plant spacing on intact fruits m-2 at 150
DAS

117
 180
May 10
160

140

Intact fruits m 150 DAS

120

100
-2

80

60

40

20

0
CIM-473 CIM-482
Cultivars

15cm 30cm

Fig.4.2.10 Interactive effect of cultivars and plant spacing on intact fruits m-2 at 150

DAS

160
June 10
140

120
Intact fruits m 100 DAS

100
-2

80

60

40

20

0
0 50 100 150
-1
Nitrogen levels (kg ha )

CIM-473 CIM-482

Fig.4.2.11 Interactive effect of nitrogen and cultivars on intact fruits m-2 at 100 DAS

118
 160
June 10
140

120
Intact fruits m 100 DAS

100
-2

80

60

40

20

0
0 50 100 150
-1
Nitrogen levels (kg ha )

CIM-473 CIM-482

Fig.4.2.12 Interactive effect of nitrogen and plant spacing on intact fruits m-2 at 100
DAS

180
June 10
160

140
Intact fruits m 150 DAS

120

100
-2

80

60

40

20

0
0 50 100 150
-1
Nitrogen levels (kg ha )

15cm 30cm

Fig.4.2.13 Interactive effect of nitrogen and plant spacing on intact fruits m-2 at 150
DAS

119
It was also revealed from the interaction between nitrogen and spacing that effect of nitrogen

was higher at narrow spacing when crop was harvested at 100 and 150 days in both sowings.

The interaction between the cultivar, plant spacing and nitrogen fertilizer doses were found to

be significant. These interactions might be the result of the differential response of cultivars to

the nitrogen fertilizer and spacing. (Fig. 4.2.8-13)

Shedding percentage (%)

Data presented in Table (4.2.19-20 May 10 and June 01) showed that there were

significant differences among different treatments of cultivar, spacing and nitrogen

fertilizer. Cultivar CIM-482 showed a significantly (P≤0.01) higher shedding percentage

throughout the plant growth than CIM-473 on both sowing dates. It is observed from the

results that spacing treatments showed a similar trend on both sowing dates (May 10 and

June 01). Narrow spacing (15 cm) treatments showed more shedding percentage trough

out the plant growth on both sowing dates and the significant difference were observed at

all growth stages (i-e 50, 100 and 150 DAS) in both sowing dates except, 50 DAS in

early sown crop. It is observed that each incremental dose of nitrogen fertilizer produced

significant effects at all growth stages except 50 kg N ha-1 which did not produce

significant effect than control. It is evident from the results that each increase of nitrogen

tended to decrease fruit shedding percentage at all growth stages in late sown crop. At 50

and 100 DAS higher doses of nitrogen 100 and 150 kg ha-1produced significant effects as

compared to zero and 50 kg N ha-1.Whereas, at 150 DAS each increment of nitrogen

produced significant effect. The significant interaction between nitrogen into plant

spacing was observed in late sown crop at final stage of the crop. This demonstrates that

fruit shedding may be decreased in wider spacing by the increase of nitrogen.

120
Table-4.2.19 Effect of cultivars sown on May 10, plant spacing and nitrogen
fertilizer on shedding percentage
Nitrogen 50 DAS 100 DAS 150 DAS
(kg ha-1) Cultivars Spacing (cm) Spacing (cm) Spacing (cm)
15 30 Means 15 30 Means 15 30 Means
CIM-473 29.8 29.2 29.5 59.7 56.4 58.1 66.8 66.3 66.6
0 CIM-482 31.8 30.5 31.2 63.3 60.6 62.0 71.6 68.8 70.2
Means 30.8 29.9 30.4 61.5 58.5 60.0 69.2 67.6 68.4
CIM-473 29.4 29.2 29.3 58.2 55.8 57.0 65.2 63.5 64.4
50 CIM-482 31.8 29.7 30.8 62.3 60.2 61.3 70.2 67.6 68.9
Means 30.6 29.5 30.1 60.3 58.0 59.2 67.7 65.6 66.7
CIM-473 27.5 27.1 27.3 54.6 54.4 54.5 63.2 62.3 62.8
100 CIM-482 29.9 29.0 29.5 61.2 59.9 60.6 67.7 66.3 67.0
Means 28.7 28.1 28.4 57.9 57.2 57.6 65.5 64.3 64.9
CIM-473 25.8 25.0 25.4 53.8 53.1 53.5 62.0 61.6 61.8
150 CIM-482 28.2 28.7 28.5 60.0 57.8 58.9 66.5 65.9 66.2
Means 27.0 26.9 27.0 56.9 55.5 56.2 64.3 63.8 64.0
S.Es
Nitrogen 0.42 0.25 0.22
Cultivars 0.46 0.31 0.14
Plant spacing 0.72 0.28 0.25
NxC 0.77 0.50 0.29
NxS 1.11 0.46 0.42
CxS 0.86 0.41 0.29
NxCxS 1.64 0.74 0.58
LSD (5%)
Nitrogen 1.04 0.61 0.54
Cultivars 1.05 0.70 0.31
Plant spacing ns 0.59 0.53
NxC ns ns ns
NxS ns ns ns
CxS ns ns ns
NxCxS ns ns ns
Sub effects of different variables
Shedding %age
Nitrogen Plant
50 100 150 50 100 150 50 100 150
levels Cultivars Spacing
DAS DAS DAS DAS DAS DAS DAS DAS DAS
(kg ha-1) (cm)
0 30.4a 60.1a 68.4a CIM-473 27.9b 55.8b 63.9b 15 29.3 59.2a 66.7a
50 30.1a 59.2b 66.7b
100 28.4b 57.6c 64.9c CIM-482 30.0a 60.7a 68.1a 30 28.6 57.3b 65.3b
150 27.0c 56.2d 64.0d

121
 Table-4.2.20 Effect of cultivars sown on June 01, plant spacing and nitrogen
fertilizer on shedding percentage
Nitrogen 50 DAS 100 DAS 150 DAS
(kg ha-1) Cultivars Spacing (cm) Spacing (cm) Spacing (cm)
15 30 Means 15 30 Means 15 30 Means
CIM-473 31.2 29.5 30.4 60.0 57.4 58.7 70.4 67.3 68.9
0 CIM-482 33.3 31.0 32.2 64.4 61.5 63.0 73.3 69.2 71.3
Means 32.3 30.3 31.3 62.2 59.5 60.9 71.9 68.3 70.1
CIM-473 30.9 29.2 30.1 59.2 56.7 58.0 67.7 64.9 66.3
50 CIM-482 32.4 30.6 31.5 62.5 61.2 61.9 70.8 68.2 69.5
Means 31.7 29.9 30.8 60.9 59.0 60.0 69.3 66.6 67.9
CIM-473 28.1 27.5 27.8 55.7 55.4 55.6 66.0 64.7 65.4
100 CIM-482 30.2 29.2 29.7 61.7 60.5 61.1 68.6 66.7 67.7
Means 29.2 28.4 28.8 58.7 58.0 58.4 67.3 65.7 66.5
CIM-473 26.4 25.6 26.0 54.6 53.8 54.2 64.5 63.7 64.1
150 CIM-482 29.6 29.3 29.5 60.9 60.1 60.5 67.7 66.5 67.1
Means 28.0 27.5 27.8 57.8 57.0 57.4 66.1 65.1 65.6
SEs
Nitrogen 0.604 0.438 0.437
Cultivars 0.411 0.339 0.260
Plant spacing 0.482 0.343 0.301
NxC 0.838 0.649 0.571
NxS 0.911 0.654 0.610
CxS 0.633 0.482 0.397
NxCxS 1.270 0.945 0.829
LSD (5%)
Nitrogen 1.48 1.07 1.07
Cultivars 0.95 0.78 0.60
Plant spacing 1.02 0.73 0.64
NxC ns ns ns
NxS ns ns ns
CxS ns ns ns
NxCxS ns ns ns
Sub effects of different variables
Shedding %age
Nitrogen Plant
50 100 150 50 100 150 50 100 150
levels Cultivars Spacing
DAS DAS DAS DAS DAS DAS DAS DAS DAS
(kg ha-1) (cm)
0 31.3a 60.9a 70.1a CIM-473 28.6b 56.6b 66.2b 15 30.3a 59.9a 68.7a
50 30.8a 60.0a 67.9b
100 28.8b 58.4b 66.6cd CIM-482 30.7a 61.6a 68.9a 30 29.0b 58.4b 66.4b
150 27.8b 57.4b 65.6d

122
Vegetative dry matter (g m-2)

Data showed that there were significant differences among different treatments of

cultivars, spacing and nitrogen fertilizer (Table-4.2.21-22 May 10 and June 01). Cultivars

showed a similar trend on both sowing dates (May 10 and June 01), however cultivar

CIM-482 produced significantly (P≤0.01) more vegetative dry matter at all growth stages

(50,100 and 150 DAS) than CIM 473. It is clear from the results that plant spacing

showed a similar observation like that of cultivars. The narrow spacing (15 cm) produced

significantly (P≤0.01) more vegetative dry matter throughout the plant growth in both

sowing dates as compared to broad spacing (30 cm). Data indicated that incremental dose

of nitrogen tended to produce more vegetative dry matter at early growth stage (50 DAS)

in early sown crop (May 10). The higher rates of nitrogen (100 and 150 kg ha-1) produced

significantly (P≤0.05 and 0.01) more vegetative dry matter than lower nitrogen rates (50

and 0 kg ha-1) early sown crop. In late sown crop June 01 at all growth stages (50,100

and 150 DAS) each incremental dose of nitrogen produced significantly (P≤0.01) more

vegetative dry matter. The interaction between nitrogen x cultivar and nitrogen x cultivar

x plant spacing were found to be significant at growth stage 100 days. The interaction

between nitrogen x cultivars and cultivars x plant spacing were found to be significant at

(150 DAS) growth stage at early sown crop May 10. The interaction between nitrogen x

cultivars and nitrogen x plant spacing were found to be significant at later growth stages

100 and 150 days at late sown crop (June 01).

The significant interactions among different treatments at later stages of the crop indicate

that nitrogen dose adjustment, cultivar selection and appropriate plant spacing may have

positive influence on crop growth and development

123
Table-4.2.21 Effect of cultivars sown on May 10, plant spacing and nitrogen
fertilizer on vegetative dry matter (g m-2)
50 DAS 100 DAS 150 DAS
Nitrogen
(kg ha-1)
Cultivars Spacing (cm) Spacing (cm) Spacing (cm)
15 30 Means 15 30 Means 15 30 Means
CIM-473 72.0 56.5 64.3 172.5 114.0 143.3 245.2 209.6 227.4
0 CIM-482 83.7 67.6 75.7 212.3 160.6 186.5 270.1 235.9 253.0
Means 77.9 62.1 70.0 192.4 137.3 164.9 257.7 222.8 240.2
CIM-473 74.6 59.8 67.2 229.3 188.4 208.9 275.6 254.7 265.2
50 CIM-482 86.2 72.4 79.3 275.6 209.4 242.5 288.0 253.3 270.7
Means 80.4 66.1 73.3 252.5 198.9 225.7 281.8 254.0 268.0
CIM-473 76.0 66.5 71.3 291.2 236.3 263.8 313.3 271.5 292.4
100 CIM-482 88.8 79.3 84.1 320.6 280.3 300.5 328.0 279.6 303.8
Means 82.4 72.9 77.7 305.9 258.3 282.1 320.7 275.6 298.1
CIM-473 81.1 69.4 75.3 319.0 264.1 291.6 335.7 275.3 305.5
150 CIM-482 90.6 84.5 87.6 365.2 341.9 353.6 356.0 286.4 321.2
Means 85.9 77.0 81.5 342.1 303.0 322.6 345.9 280.9 313.4
SEs
Nitrogen 1.63 3.39 2.49
Cultivars 0.95 1.40 2.35
Plant spacing 1.20 1.84 1.65
NxC 2.11 3.92 4.16
NxS 2.35 4.28 3.41
CxS 1.53 2.31 2.87
NxCxS 3.19 5.38 5.30
LSD (5%)
Nitrogen 3.98 8.31 6.11
Cultivars 2.20 3.23 5.44
Plant spacing 2.54 3.91 3.49
NxC ns 9.48 ns
NxS ns ns 7.83
CxS ns ns 6.45
NxCxS ns 12.26 ns
Sub effects of different variables
Vegetative dry matter (g m-2)
Nitrogen Plant
50 100 150 50 100 150 50 100 150
levels Cultivars Spacing
DAS DAS DAS DAS DAS DAS DAS DAS DAS
(kg ha-1) (cm)
0 70.0b 164.9d 240.2d CIM-473 69.5b 226.9b 272.6b 15 81.7a 273.2a 301.5a
50 73.3b 225.7c 268.0c
100 77.7a 282.2b 298.1b CIM-482 81.7a 270.8a 287.2a 30 69.5b 224.4b 258.3b
150 81.5a 322.6a 313.4a

124
Table-4.2.22 Effect of cultivars sown on Jun 01, plant spacing and nitrogen
fertilizer on vegetative dry matter (g m-2)
50 DAS 100 DAS 150 DAS
Nitrogen
Cultivars Spacing (cm) Spacing (cm) Spacing (cm)
(kg ha-1)
15 30 Means 15 30 Means 15 30 Means
CIM-473 72.8 57.0 64.9 186.2 125.8 156.0 258.0 220.0 239.0
0 CIM-482 84.2 68.0 76.1 232.7 162.4 197.6 284.0 251.0 267.5
Means 78.5 62.5 70.5 209.5 144.1 176.8 271.0 235.5 253.3
CIM-473 74.8 60.4 67.6 240.6 192.3 216.5 298.0 263.0 280.5
50 CIM-482 87.5 73.0 80.3 309.8 215.0 262.4 296.0 265.0 280.5
Means 81.2 66.7 74.0 275.2 203.7 239.5 297.0 264.0 280.5
CIM-473 76.2 67.7 72.0 299.5 242.3 270.9 331.0 282.0 306.5
100 CIM-482 89.9 80.1 85.0 348.8 304.1 326.5 339.0 290.0 314.5
Means 83.1 73.9 78.5 324.2 273.2 298.7 335.0 286.0 310.5
CIM-473 82.5 69.9 76.2 329.9 283.4 306.7 342.0 290.0 316.0
150 CIM-482 90.2 85.5 87.9 386.9 357.7 372.3 365.0 298.0 331.5
Means 86.4 77.7 82.1 358.4 320.6 339.5 353.5 294.0 323.8
SEs
Nitrogen 0.29 1.43 1.82
Cultivars 0.86 1.82 2.27
Plant spacing 1.23 1.58 2.00
NxC 1.25 2.94 3.69
NxS 1.77 2.66 3.36
CxS 1.51 2.41 3.03
NxCxS 2.77 4.32 5.44
LSD (5%)
Nitrogen 0.72 3.50 4.46
Cultivars 1.99 4.20 5.25
Plant spacing 2.64 3.36 4.24
NxC ns 6.89 8.65
NxS ns 5.88 7.46
CxS ns ns ns
NxCxS ns 9.61 ns
Sub effects of different variables
Vegetative dry matter (g m-2)
Nitrogen Plant
50 100 150 50 100 150 50 100 150
levels Cultivars Spacing
DAS DAS DAS DAS DAS DAS DAS DAS DAS
(kg ha-1) (cm)
0 70.5d 176.8d 253.3d CIM-473 70.18b 237.5b 285.5b 15 82.3a 291.8a 314.1a
50 74.0c 239.5c 280.5c
100 78.5b 298.7b 310.5b CIM-482 82.3a 289.7a 298.5a 30 70.2b 235.4b 269.9b
150 82.1a 339.5a 323.8a

125
Reproductive dry matter (g m-2)

Data presented in Tables (4.2.23-24 May 10 and June 01) showed that there were

significant differences among different treatments of cultivars, spacing and nitrogen

fertilizer. Cultivar CIM-473 produced significantly (P≤0.01) more reproductive dry

matter throughout the cropping season in both sowing dates. It is observed from the

results that spacing treatment had similar impact in both sowing dates (May 10 and June

01). Narrow spacing (15 cm) treatments produced significantly (P≤0.01) more

reproductive dry matter throughout the cropping season than broad spacing (30 cm) in

both sowing dates. Data showed that each incremental dose of nitrogen fertilizer at all

growth stages (50,100 and 150 DAS) in both sowing dates produced significantly

(P≤0.01) more reproductive dry matter and highest rate of nitrogen fertilizer (150 kg ha-1)

produced maximum reproductive dry matter throughout the cropping season in early and

late sown crops (May 10 and June 01). It is evident from the results that interaction

between cultivar x nitrogen and cultivar x spacing were found to be significant in both

sowing dates at growth stages 100 and 150 DAS. Whereas, the interaction between

nitrogen x cultivar x spacing at growth stage (100 DAS) and nitrogen x plant spacing at

growth stage (150 DAS) were found to be significant in early and late sowing date. The

positive interactions among different treatments at later stage of crop demonstrated that

nitrogen fertilizer management, cultivar selection and appropriate plant spacing would

favour collectively in achieving maximum reproductive development in cotton crop.

(Fig.4.2.14)

126
Table-4.2.23 Effect of cultivars sown on May 10, plant spacing and nitrogen
fertilizer on reproductive dry matter (g m-2)
50 DAS 100 DAS 150 DAS
Nitrogen
Cultivars Spacing (cm) Spacing (cm) Spacing (cm)
(kg ha-1)
15 30 Means 15 30 Means 15 30 Means
CIM-473 40.5 28.8 34.7 226.0 141.4 183.7 355.5 283.0 319.3
0 CIM-482 31.8 22.3 27.1 145.6 89.6 117.6 294.4 238.3 266.4
Means 36.2 25.6 30.9 185.8 115.5 150.7 325.0 260.7 292.9
CIM-473 44.0 33.5 38.8 318.7 248.7 283.7 435.3 354.0 394.7
50 CIM-482 37.9 26.8 32.4 223.2 148.7 186.0 325.4 268.5 297.0
Means 41.0 30.2 35.6 271.0 198.7 234.9 380.4 311.3 345.9
CIM-473 47.9 39.9 43.9 416.9 328.4 372.7 504.4 393.7 449.1
100 CIM-482 41.7 31.7 36.7 278.9 215.8 247.4 393.6 315.9 354.8
Means 44.8 35.8 40.3 347.9 272.1 310.0 449.0 354.8 402.0
CIM-473 52.7 43.7 48.2 468.9 377.7 423.3 550.5 418.5 484.5
150 CIM-482 45.3 35.5 40.4 336.3 276.9 306.6 459.2 352.3 405.8
Means 49.0 39.6 44.3 402.6 327.3 365.0 504.9 385.4 445.2
SEs
Nitrogen 0.76 2.08 1.78
Cultivars 0.71 2.28 1.75
Plant spacing 1.28 1.38 2.18
NxC 1.26 3.84 3.05
NxS 1.96 2.85 3.56
CxS 1.47 2.67 2.80
NxCxS 2.83 4.73 5.33
LSD (5%)
Nitrogen 1.85 5.09 4.35
Cultivars 1.65 5.27 4.04
Plant spacing 2.71 2.93 4.63
NxC ns 9.03 7.18
NxS ns ns 7.85
CxS ns 6.03 6.14
NxCxS ns 10.75 ns
Sub effects of different variables
Reproductive dry matter (gm-2)
Nitrogen Plant
50 100 150 50 100 150 50 100 150
levels Cultivars Spacing
DAS DAS DAS DAS DAS DAS DAS DAS DAS
(kg ha-1) (cm)
0 30.9d 150.7d 292.9d CIM-473 41.4a 315.9a 400.7a 15 42.8a 301.8a 414.8a
50 35.6c 234.9c 345.9c
100 40.3b 310.1b 402.0b CIM-482 34.2b 214.4b 331.0b 30 32.8b 228.4b 328.1b
150 44.3a 365.0a 445.2a

127
Table-4.2.24 Effect of cultivars sown on June 01, plant spacing and nitrogen fertilizer
on reproductive dry matter (g m-2)
50 DAS 100 DAS 150 DAS
Nitrogen
Cultivars Spacing (cm) Spacing (cm) Spacing (cm)
(kg ha-1)
15 30 Means 15 30 Means 15 30 Means
CIM-473 37.9 27.5 32.7 219.5 132.4 176.0 340.6 266.2 303.4
0 CIM-482 29.5 21.1 25.3 125.4 79.6 102.5 281.2 225.9 253.6
Means 33.7 24.3 29.0 172.5 106.0 139.3 310.9 246.1 278.5
CIM-473 41.1 32.0 36.6 307.3 226.9 267.1 420.2 349.8 385.0
50 CIM-482 35.9 24.8 30.4 182.8 118.3 150.6 325.6 265.0 295.3
Means 38.5 28.4 33.5 245.1 172.6 208.9 372.9 307.4 340.2
CIM-473 45.7 39.3 42.5 389.4 303.6 346.5 486.6 380.7 433.7
100 CIM-482 40.5 28.8 34.7 226.7 185.5 206.1 389.9 313.2 351.6
Means 43.1 34.1 38.6 308.1 244.6 276.3 438.3 347.0 392.7
CIM-473 51.2 42.6 46.9 442.1 362.8 402.5 523.3 406.0 464.7
150 CIM-482 42.4 33.3 37.9 286.3 236.1 261.2 445.3 339.7 392.5
Means 46.8 38.0 42.4 364.2 299.5 331.9 484.3 372.9 428.6
SEs
Nitrogen 0.98 1.71 2.90
Cultivars 0.65 2.05 3.18
Plant spacing 0.93 1.80 2.05
NxC 1.34 3.36 5.35
NxS 1.64 3.06 4.10
CxS 1.13 2.72 3.78
NxCxS 2.29 4.92 6.74
LSD 5%)
Nitrogen 2.40 4.18 7.11
Cultivars 1.49 4.72 7.34
Plant spacing 1.96 3.81 4.35
NxC ns 7.88 ns
NxS ns ns 9.38
CxS ns 6.06 8.52
NxCxS ns 10.95 ns
Sub effects of different variables
Reproductive dry matter (gm-2)
Nitrogen Plant
50 100 150 50 100 150 50 100 150
levels Cultivars Spacing
DAS DAS DAS DAS DAS DAS DAS DAS DAS
(kg ha-1) (cm)
0 29.0d 139.3d 278.5d
CIM-473 39.7a 298.0a 396.7a 15 40.5a 272.5a 401.6a
50 33.5c 208.9c 340.2c
100 38.6b 276.3b 392.7b CIM-482 32.1b 180.1b 323.3b 30 31.2b 205.7b 318.4b
150 42.4a 331.9a 428.6a

128
 400
May 10
350
Reproductive dry matter g m 100
300
-2

250

200
DAS

150

100

50

0
CIM-473 CIM-482
Cultivars

15cm 30cm

Fig.4.2.14 Interactive effect of cultivars and plant spacing on reproductive dry

matter g m-2 at 100 DAS

Reproductive-vegetative ratio

Results indicated that there were significant differences among different treatments of

cultivars, spacing and nitrogen fertilizer for reproductive-vegetative ratio. Cultivars

showed a similar trend in both sowing dated in Tables (4.2.25-26 May 10 and June 01).

However, cultivar CIM 473 produced significantly (P≤0.01) more reproductive-

vegetative ratio than cultivar CIM-482 at all growth stages (50,100 and 150 DAS) in both

sowing dates. It is observed from the results that spacing treatments had similar impact in

both sowing dates. Narrow spacing (15 cm) produced significantly (P≤0.01) higher

reproductive-vegetative ratio at all growth stages in early and late sowing dates.

129
Table-4.2.25 Effect of cultivars sown on May 10, plant spacing and nitrogen
fertilizer on reproductive-vegetative ratio
50 DAS 100 DAS 150 DAS
Nitrogen
Cultivars Spacing (cm) Spacing (cm) Spacing (cm)
(kg ha-1)
15 30 Means 15 30 Means 15 30 Means
CIM-473 0.56 0.51 0.54 1.31 1.24 1.28 1.45 1.35 1.40
0 CIM-482 0.38 0.33 0.36 0.69 0.56 0.63 1.09 1.01 1.05
Means 0.47 0.42 0.45 1.00 0.90 0.95 1.27 1.18 1.23
CIM-473 0.59 0.56 0.58 1.39 1.32 1.36 1.58 1.39 1.49
50 CIM-482 0.44 0.37 0.41 0.81 0.71 0.76 1.13 1.06 1.10
Means 0.52 0.47 0.50 1.10 1.02 1.06 1.36 1.23 1.30
CIM-473 0.63 0.60 0.62 1.43 1.39 1.41 1.61 1.45 1.53
100 CIM-482 0.47 0.40 0.44 0.87 0.77 0.82 1.20 1.13 1.17
Means 0.55 0.50 0.53 1.15 1.08 1.12 1.41 1.29 1.35
CIM-473 0.65 0.63 0.64 1.47 1.43 1.45 1.64 1.52 1.58
150 CIM-482 0.50 0.42 0.46 0.92 0.81 0.87 1.29 1.23 1.26
Means 0.58 0.53 0.56 1.20 1.12 1.16 1.47 1.38 1.42
SEs
Nitrogen 0.01 0.01 0.02
Cultivars 0.02 0.02 0.012
Plant spacing 0.02 0.02 0.01
NxC 0.03 0.02 0.02
NxS 0.03 0.03 0.02
CxS 0.02 0.02 0.02
NxCxS 0.04 0.04 0.03
LSD (5%)
Nitrogen 0.03 0.04 0.04
Cultivars 0.03 0.03 0.03
Plant spacing 0.04 0.03 0.02
NxC ns ns ns
NxS ns ns ns
CxS ns ns ns
NxCxS ns ns ns
Sub effects of different variables
Reproductive vegetative ratio
Nitrogen Plant
50 100 150 50 100 150 50 100 150
levels Cultivars Spacing
DAS DAS DAS DAS DAS DAS DAS DAS DAS
(kg ha-1) (cm)
0 0.45c 0.96d 1.23d CIM-473 0.60a 1.38a 1.50a 15 0.53a 1.11a 1.38a
50 0.50b 1.06c 1.30c
100 0.53a 1.12b 1.35b CIM-482 0.42b 0.77b 1.15b 30 0.48b 1.03b 1.27b
150 0.55a 1.16a 1.42a

130
Table-4.2.26 Effect of cultivars sown on June 01, plant spacing and nitrogen
fertilizer on reproductive-vegetative ratio
50 DAS 100 DAS 150 DAS
Nitrogen
Cultivars Spacing (cm) Spacing (cm) Spacing (cm)
(kg ha-1)
15 30 Means 15 30 Means 15 30 Means
CIM-473 0.52 0.48 0.50 1.18 1.05 1.12 1.32 1.21 1.27
0 CIM-482 0.35 0.31 0.33 0.54 0.49 0.52 0.99 0.90 0.95
Means 0.44 0.40 0.42 0.86 0.77 0.82 1.16 1.06 1.11
CIM-473 0.55 0.53 0.54 1.24 1.18 1.21 1.41 1.33 1.37
50 CIM-482 0.41 0.34 0.38 0.59 0.55 0.57 1.10 1.00 1.05
Means 0.48 0.44 0.46 0.92 0.87 0.89 1.26 1.17 1.21
CIM-473 0.60 0.58 0.59 1.30 1.25 1.28 1.47 1.35 1.41
100 CIM-482 0.45 0.36 0.41 0.65 0.61 0.63 1.15 1.08 1.12
Means 0.53 0.47 0.50 0.98 0.93 0.96 1.31 1.22 1.27
CIM-473 0.62 0.61 0.62 1.34 1.28 1.31 1.53 1.40 1.47
150 CIM-482 0.47 0.39 0.43 0.74 0.66 0.70 1.22 1.14 1.18
Means 0.55 0.50 0.53 1.04 0.97 1.01 1.38 1.27 1.33
SEs
Nitrogen 0.01 0.01 0.01
Cultivars 0.01 0.01 0.01
Plant spacing 0.01 0.01 0.01
NxC 0.02 0.02 0.02
NxS 0.02 0.02 0.02
CxS 0.01 0.02 0.02
NxCxS 0.03 0.03 0.03
LSD (5%)
Nitrogen 0.03 0.03 0.02
Cultivars 0.02 0.03 0.03
Plant spacing 0.02 0.02 0.02
NxC ns ns ns
NxS ns ns ns
CxS ns ns ns
NxCxS ns ns ns
Sub effects of different variables
Reproductive vegetative ratio
Nitrogen Plant
50 100 150 50 100 150 50 100 150
levels Cultivars Spacing
DAS DAS DAS DAS DAS DAS DAS DAS DAS
(kg ha-1) (cm)
0 0.42d 0.82d 1.11d CIM-473 0.56a 1.23a 1.38a 15 0.50a 0.95a 1.28a
50 0.46c 0.89c 1.21c
100 0.50b 0.96b 1.27b CIM-482 0.39b 0.61b 1.08b 30 0.45b 0.89b 1.18b
150 0.53a 1.01a 1.33a

131
It is evident from the results that each incremental dose of nitrogen fertilizer produced

significantly (P≤0.05) higher reproductive-vegetative ratio at all growth stages (50,100

and 150 DAS) in late sown crop on June 01. In early sown crop (June 01) similar trend

was observed at (100 and 150 DAS) whereas, in (50 DAS) all doses of nitrogen fertilizer

produced significantly higher reproductive-vegetative ratio as compared to control. It is

obvious from the results that in early sown crop on May 10 the interactive effect of

cultivar and plant spacing at final stage (150 DAS) of the crop were found to be

significant.

Total plant dry matter (g m-2)

Data presented in Table (4.2.27-28) showed that there were significant differences among

different treatments of cultivars, spacing and nitrogen fertilizer. Cultivar CIM 473

produced significantly (P≤0.01) higher total plant dry matter throughout the growth

stages (50,100 and 150 DAS) in early sown crop May 10.it is observe from the results

that spacing treatments in all growth stages showed similar trend. Narrow spacing (15

cm) produced significantly (P≤0.01) more total plant dry matter than broad spacing (30

cm) throughout cropping season. It is clear from the results that each incremental dose of

nitrogen produced significantly (P≤0.01) higher total plant dry matter at all growth stages

in early sown crop May 10. In late sown crop on June 01 almost similar observation was

observed. Cultivar CIM 473 produced significantly higher total plant dry matter than

CIM 482 at later stages of growth (100 and 150 DAS). However, CIM 482 at 50 DAS

produced higher total plant dry matter than CIM 473 but the differences were non

significant statistically. Results showed that narrow spacing (15 cm) produced

significantly (P≤0.01) higher total plant dry matter than broad spacing (30 cm)

throughout cropping season. It is observed from the results that each incremental dose of

nitrogen fertilizer produced significantly higher total plant dry matter at later growth

132
stages (100 and 150 DAS) and at the early stage (50 DAS), produced higher total plant

dry matter at higher doses (100 and150 kg ha-1) of nitrogen fertilizer, although non

significant with each other but produced significantly higher total plant dry matter than

lower dose of nitrogen (50 kg ha-1 and control).

Table-4.2.27 Effect of cultivars sown on May 10, plant spacing and nitrogen
fertilizer on total plant dry matter (g m-2)
50 DAS 100 DAS 150 DAS
Nitrogen
Cultivars Spacing (cm) Spacing (cm) Spacing (cm)
(kg ha-1)
15 30 Means 15 30 Means 15 30 Means
CIM-473 112.5 85.3 98.9 398.5 255.4 327.0 600.7 492.6 546.7
0 CIM-482 115.5 89.9 102.7 357.9 250.2 304.1 564.5 474.2 519.4
Means 114.0 87.6 100.8 378.2 252.8 315.5 582.6 483.4 533.0
CIM-473 118.6 93.3 106.0 548.0 437.1 492.6 710.9 608.7 659.8
50 CIM-482 124.1 99.2 111.7 498.8 358.1 428.5 613.4 521.8 567.6
Means 121.4 96.3 108.9 523.4 397.6 460.5 662.2 565.3 613.7
CIM-473 123.9 106.4 115.2 708.1 564.7 636.4 817.7 665.2 741.5
100 CIM-482 130.5 111.0 120.8 599.5 496.1 547.8 721.6 595.5 658.6
Means 127.2 108.7 118.0 653.8 530.4 595.1 769.7 630.4 700.1
CIM-473 133.8 113.1 123.5 787.9 641.8 714.9 886.2 693.8 790.0
150 CIM-482 135.9 120.0 128.0 701.5 618.8 660.2 815.2 638.6 726.9
Means 134.9 116.6 125.8 744.7 630.3 687.5 850.7 666.2 758.5
SEs
Nitrogen 2.02 3.99 2.61
Cultivars 0.93 2.62 3.01
Plant spacing 1.94 2.05 2.76
NxC 2.42 5.44 5.00
NxS 3.41 4.93 4.70
CxS 2.15 3.33 4.08
NxCxS 4.56 6.82 7.45
LSD (5%)
Nitrogen 4.97 9.78 6.42
Cultivars 2.16 6.05 6.95
Plant spacing 4.10 4.35 5.85
NxC ns 12.98 11.73
NxS ns ns 10.45
CxS ns 7.44 9.07
NxCxS ns 15.60 ns
Sub effects of different variables
Plant dry matter (gm-2)
Nitrogen Plant
50 100 150 50 100 150 50 100 150
levels Cultivars Spacing
DAS DAS DAS DAS DAS DAS DAS DAS DAS
(kg ha-1) (cm)
0 100.8d 315.6d 533.1d CIM-473 110.9b 540.5a 684.5a 15 124.4a 575.0a 716.3a
50 108.9c 460.6c 613.7c
100 118.0b 587.6b 700.1b CIM-482 115.8a 485.2b 618.1b 30 102.3b 450.5b 586.3b
150 125.8a 687.6a 758.5a

133
 800
May-10
700
Plant dry matter fruits g m 100

600
-2

500

400
DAS

300

200

100

0
0 50 100 150
-1
Nitrogen levels (kg ha )

CIM-473 CIM-482

Fig.4.2.15 Interactive effect of nitrogen and cultivars on total plant dry

matter g m-2 at 100 DAS

It is evident from the results that interaction between nitrogen x cultivar and cultivar x

spacing were found to be significant at later growth stages of the crop in both sowing dates

(May 10 and June 01). Whereas, the interaction between nitrogen x spacing was significant at

final growth stage (150 DAS) in early as well as in late sown crop. The interactions among

nitrogen x cultivar x spacing were found to be significant at (100 DAS) both in early and late

sown crop. The positive interaction among different treatments indicates that maximum

growth and development of cotton plant may be achieved due to collective effect of nitrogen

management, cultivar selection and plant spacing adjustment (Fig. 2.4.15-25).

134
Table-4.2.28 Effect of cultivars sown on June 01, plant spacing and nitrogen
fertilizer on total plant dry matter (g m-2)
50 DAS 100 DAS 150 DAS
Nitrogen
Cultivars Spacing (cm) Spacing (cm) Spacing (cm)
(kg ha-1)
15 30 Means 15 30 Means 15 30 Means
CIM-473 110. 7 84.5 97.6 405.7 258.2 332.0 598.6 486.2 542.4
0 CIM-482 113.7 89.1 101.4 358.1 242.0 300.1 565.2 476.9 521.1
Means 112.2 86.8 99.5 381.9 250.1 316.0 581.9 481.6 531.8
CIM-473 115.9 92.4 104.2 554.9 419.2 487.1 718.2 612.8 665.5
50 CIM-482 123.4 97.8 110.6 492.6 333.3 413.0 621.6 530.0 575.8
Means 119.7 95.1 107.4 523.8 376.3 450.1 669.9 571.4 620.7
CIM-473 121.9 107.0 114.5 688.9 545.9 617.4 817.6 662.7 740.2
100 CIM-482 130.4 108.9 119.7 575.5 489.6 532.6 728.9 603.2 666.1
Means 126.2 108.0 117.1 632.2 517.8 575.0 773.3 633.0 703.2
CIM-473 133.7 112.5 123.1 772.0 646.2 709.1 865.3 696.0 780.7
150 CIM-482 132.6 118.8 125.7 673.2 595.8 634.5 810.3 637.3 723.8
Means 133.2 115.7 124.4 722.6 621.0 671.8 837.8 666.7 752.3
SEs
Nitrogen 3.95 1.24 4.22
Cultivars 2.52 2.28 4.20
Plant spacing 3.27 2.28 2.85
NxC 6.09 3.45 5.83
NxS 4.12 3.22 5.07
CxS 8.42 5.71 9.24
NxCxS 5.31 3.45 7.27
LSD (5%)
Nitrogen 9.67 3.03 10.34
Cultivars ns 5.26 9.70
Plant spacing 6.92 4.83 6.03
NxC ns 8.03 17.17
NxS ns 7.46 13.37
CxS ns 7.13 11.41
NxCxS ns 12.54 ns
Sub effects of different variables
Plant dry matter (gm-2)
Nitrogen Plant
50 100 150 50 100 150 50 100 150
levels Cultivars Spacing
DAS DAS DAS DAS DAS DAS DAS DAS DAS
(kg ha-1) (cm)
0 99.5b 316.1d 531.8d CIM-473 109.9 536.4a 682.2a 15 122.8a 565.1a 715.7a
50 107.4b 450.1c 620.7c
100 117.1a 575.0b 703.2b CIM-482 114.4 470.1b 621.8b 30 101.4b 441.3b 588.2b
150 124.4a 671.8a 752.3a

135
 700
May- 10
Plant dry matter fruits g m 100 600

500
-2

400
DAS

300

200

100

0
CIM-473 CIM-482
Cultivars

15cm 30cm

Fig.4.2.16 Interactive effect of cultivars and plant spacing on total plant dry
matter g m-2 at 100 DAS

900
May-10
800
Plant dry matter fruits g m 150

700
-2

600

500
DAS

400

300

200

100

0
0 50 100 150
-1
Nitrogen levels (kg ha )

15cm 30cm

Fig.4.2.17 Interactive effect of nitrogen and plant spacing on total plant dry
matter g m-2 at 150 DAS

136
 900
CIM-473
800

Plant dry matter fruits g m 100 700

-2

600

500
DAS

400

300

200

100

0
0 50 100 150
-1
Nitrogen levels (kg ha )

15cm 30cm

800
CIM-482
700
Plant dry matter fruits g m 100

600
-2

500

400
DAS

300

200

100

0
0 50 100 150
-1
Nitrogen levels (kg ha )

15cm 30cm
Fig.4.2.18 Interactive effect of nitrogen, plant spacing and cultivars on total plant
dry matter g m-2 at 100 DAS (May-10)

137
 800
May-10
700

Plant dry matter fruits g m 150

600
-2
500

400
DAS

300

200

100

0
CIM-473 CIM-482
Cultivars

15cm 30cm

Fig.4.2.19 Interactive effect of cultivars and plant spacing on total plant dry
matter g m-2 at 150 DAS

800
June-01
700
Plant dry matter fruits g m 100

600
-2

500

400
DAS

300

200

100

0
0 50 100 150
-1
Nitrogen levels (kg ha )

15cm 30cm

Fig.4.2.20 Interactive effect of nitrogen and plant spacing on total plant dry
matter g m-2 at 100 DAS

138
 700
June-01
600

Plant dry matter fruits g m 100

-2
500

DAS 400

300

200

100

0
CIM-473 CIM-482
Cultivars

15cm 30cm

Fig.4.2.21 Interactive effect of cultivars and plant spacing on total plant dry
matter g m-2 at 100 DAS

900
June-01
800
Plant dry matter fruits g m 150

700
-2

600

500
DAS

400

300

200

100

0
0 50 100 150
-1
Nitrogen levels (kg ha )

CIM-473 CIM-482

Fig.4.2.22 Interactive effect of nitrogen and cultivars on total plant dry matter
g m-2 at 150 DAS

139
 900
CIM-473
800
Plant dry matter fruits g m 100 700
-2

600

500
DAS

400

300

200

100

0
0 50 100 150
-1
Nitrogen levels (kg ha )

15cm 30cm

800
CIM-482
700
Plant dry matter fruits g m 100

600
-2

500

400
DAS

300

200

100

0
0 50 100 150
-1
Nitrogen levels (kg ha )

15cm 30cm

Fig.4.2.23 Interactive effect of nitrogen, plant spacing and cultivars on total plant
dry matter g m-2 at 100 DAS (June-01)

140
 900
June-01
800
Plant dry matter fruits g m 150 700
-2

600

500
DAS

400

300

200

100

0
0 50 100 150
-1
Nitrogen levels (kg ha )

15cm 30cm

Fig.4.2.24 Interactive effect of nitrogen and plant spacing on total plant dry
matter g m-2 at 150 DAS

800
June-01
750
Plant dry matter fruits g m 150

700
-2

650

600
DAS

550

500

450

400
CIM-473 CIM-482
Cultivars

15cm 30cm

Fig.4.2.25 Interactive effect of cultivars and plant spacing on total plant dry
matter g m-2 at 150 DAS

141
 Staple length (mm)
Data showed that staple length of cultivar CIM-482 was significantly higher than CIM-

473 (Table-4.2.29) for both early and late sown crops.

Table-4.2.29 Effect of cultivars, plant spacing and nitrogen fertilizer at different

sowing dates on staple length (mm)
Treatments May-10 June-01
Nitrogen Cultivars Plant spacing Plant spacing
(kg ha-1) 15 cm 30 cm Means 15 cm 30 cm Means
CIM-473 28.0 28.0 28.0 28.7 28.4 28.6
0
CIM-482 28.2 28.5 28.4 28.2 28.1 28.2
Means 28.1 28.3 28.2 28.5 28.3 28.4
CIM-473 28.2 28.3 28.3 28.2 28.2 28.2
50
CIM-482 28.5 28.5 28.5 28.7 29.1 28.9
Means 28.4 28.4 28.4 28.5 28.7 28.6
CIM-473 28.0 28.2 28.1 28.4 28.4 28.6
100
CIM-482 28.5 28.5 28.5 28.7 28.1 28.2
Means 28.3 28.4 28.3 28.6 28.3 28.4
CIM-473 28.0 28.4 28.2 29.1 28.8 29.0
150
CIM-482 28.8 28.7 28.8 29.1 28.9 29.0
Means 28.4 28.6 28.5 29.1 28.9 29.0
SEs
Nitrogen 0.24 0.11
Cultivars 0.14 0.08
Plant spacing 0.11 0.06
NxC 0.31 0.16
NxS 0.28 0.14
CxS 0.18 0.10
NxCxS 0.38 0.20
LSD (5%)
Nitrogen ns 0.27
Cultivars 0.33 0.19
Plant spacing ns ns
NxC ns 0.38
NxS ns 0.32
CxS ns 0.23
NxCxS ns ns
Sub effects of different variables
May -10 June- 01
Nitrogen Staple Staple Plant Staple Nitrogen Staple Staple Plant Staple
levels length Cultivars length Spacing length levels length Cultivars length Spacing length
(kg ha-1) (mm) (mm) (cm) (mm) (kg ha-1) (mm) (mm) (cm) (mm)
0 28.2 CIM-473 28.2b 15 28.3 0 28.4c CIM-473 28.6b 15 28.7
50 28.4 50 28.6bc
100 28.4 CIM-482 28.6a 30 28.5 100 28.8ab CIM-482 28.8a 30 28.7
150 28.5 150 29.0a

142
Nitrogen fertilizer slightly increased the staple length but the differences were not

significant statistically with early sown crop. It is observed that in late sown crop

treatments, each increase of nitrogen fertilizer tended to increase the staple length

however, the higher nitrogen rates (100 and 150 kg ha-1) produced significantly fiber with

longer staple than zero nitrogen rate (P≤0.05 and 0.01). It is interesting that in early sown

crop the interactions between different treatments were not significant while late sown

crops showed significant interactions between different treatments of cultivars, nitrogen

and plant spacings. These significant differences might be occurred because the cultivar

CIM-482 gave better response to nitrogen application which resulted in longer staple

length.

Uniformity index (% age)

Results showed that uniformity ratio was influenced significantly by the treatments of

cultivars (Table-4.2.30).Thus, cultivar CIM-473 produced significantly fiber with higher

uniformity ratio than CIM-482 on both early as well as late sown crop (May 10 and June

01). It is also observed that nitrogen application did not affect the uniformity ratio when

applied to early sown crop however, when applied to late sown crop showed a slight

increase in ratio but the differences were not statistically significant. Again spacing

treatments did not affect the uniformity ratio of the crops.

It is evident from the results that interactions of different treatments were found to be

non-significant when crop sown early on May 10. However, there were significant

interactions between different treatments of cultivars, spacing and nitrogen fertilizer in

late sown crop on June 01. These significant effects might because the cultivar CIM-473

143
gave better response to nitrogen fertilizer which resulted in higher values of uniformity

ratio.

Table-4.2.30 Effect of cultivars, plant spacing and nitrogen fertilizer at different

sowing dates on uniformity index (% age)
Treatments May-10 June-01
Nitrogen Cultivars Plant spacing Plant spacing
(kg ha-1) 15 cm 30 cm Means 15 cm 30 cm Means
CIM-473 82.7 82.9 82.8 83.9 82.4 83.2
0
CIM-482 82.3 82.5 82.4 82.4 82.9 82.7
Means 82.5 82.7 82.6 83.2 82.7 83.0
CIM-473 83.8 83.4 83.6 82.6 83.2 82.9
50
CIM-482 83.1 82.3 82.7 82.7 82.9 82.8
Means 83.5 82.9 83.2 82.7 83.1 82.9
CIM-473 82.5 83.5 83.0 83.5 82.7 83.1
100
CIM-482 82.2 82.9 82.6 81.5 81.1 81.3
Means 82.4 83.2 82.8 82.5 81.9 82.2
CIM-473 83.2 82.8 83.0 82.8 83.4 83.1
150
CIM-482 82.8 82.3 82.6 82.9 82.6 82.8
Means 83.0 82.6 82.8 82.9 83.0 83.0
SEs
Nitrogen 0.24 0.25
Cultivars 0.20 0.11
Plant spacing 0.28 0.10
NxC 0.36 0.29
NxS 0.46 0.28
CxS 0.34 0.14
NxCxS 0.66 0.35
LSD (5%)
Nitrogen ns ns
Cultivars 0.45 0.25
Plant spacing ns ns
NxC ns 0.69
NxS ns 0.66
CxS ns ns
NxCxS ns 0.80
Sub effects of different variables
May -10 June- 01
Uni- Uni- Uni- Uni- Uni- Uni-
Nitrogen Plant Nitrogen Plant
formity formity formity formity formity formity
levels Cultivars spacing levels Cultivars Spacing
index index index index index index
(kg ha-1) (cm) (kg ha-1) (cm)
(%age) (%age) (%age) (%age) (%age) (%age)
0 82.6 CIM-473 83.1a 15 82.9 0 83.0 CIM-473 83.1a 15 82.8
50 83.2 50 82.9
100 82.8 CIM-482 82.6b 30 82.9 100 82.2 CIM-482 82.4b 30 82.7
150 82.8 150 83.0

144
 Micronaire value (ug inch-1)
Results relating to micronaire revealed that cultivars influenced significantly the

micronaire values (Table-4.2.31).

Table-4.2.31 Effects of cultivars, plant spacing and nitrogen fertilizer o at different

sowing dates on micronaire value (ug inch-1)
Treatments May-10 June-01
Nitrogen Cultivars Plant spacing Plant spacing
(kg ha-1) 15 cm 30 cm Means 15 cm 30 cm Means
CIM-473 4.5 4.6 4.5 4.6 4.3 4.5
0
CIM-482 5.1 5.2 5.1 5.0 4.9 5.0
Means 4.8 4.9 4.8 4.8 4.6 4.8
CIM-473 4.6 4.6 4.6 4.6 4.7 4.7
50
CIM-482 5.2 5.2 5.2 5.0 5.1 5.1
Means 4.9 4.9 4.9 4.8 4.9 4.9
CIM-473 4.4 4.6 4.5 4.5 4.4 4.5
100
CIM-482 5.1 5.1 5.1 5.2 4.8 5.0
Means 4.8 4.9 4.8 4.9 4.6 4.8
CIM-473 4.6 4.6 4.6 4.3 4.4 4.4
150
CIM-482 5.2 5.1 5.2 5.1 4.7 4.9
Means 4.9 4.9 4.9 4.7 4.6 4.7
SEs
Nitrogen 0.05 0.03
Cultivars 0.08 0.04
Plant spacing 0.04 0.06
NxC 0.12 0.06
NxS 0.08 0.05
CxS 0.09 0.05
NxCxS 0.15 0.08
LSD (5%)
Nitrogen ns 0.06
Cultivars 0.18 0.08
Plant spacing ns 0.06
NxC ns ns
NxS ns 0.11
CxS ns 0.10
NxCxS ns 0.18
Sub effects of different variables
May -10 June- 01
Nitrogen Micro- Micro- Plant Micro- Nitrogen Micro- Micro- Plant Micro-
levels naire Cultivars naire Spacing naire levels naire Cultivars naire Spacing naire
(kg ha-1) (ug inch-1) (ug inch-1) (cm) (ug inch-1) (kg ha-1) (ug inch-1) (ug inch-1) (cm) (ug inch-1)
0 4.9 CIM-473 4.6b 15 4.9 0 4.8b CIM-473 4.5b 15 4.8a
50 7.9 50 4.9a
100 4.8 CIM-482 5.2a 30 4.9 100 4.8b CIM-482 5.0a 30 4.7b
150 4.9 150 4.7c

145
Thus, cultivar CIM-473 produced significantly (P≤0.05) the lower value of micronaire on

both sowing dates (May 10 and June 01). It is clear from the results that the higher

nitrogen rates (100 and 150 kg ha-1) produced significantly lower values of micronaire

than lower rates of nitrogen fertilizer (i.e. zero and 50 kg ha-1) in late sown crop on June

01.Similarly, the treatments of 15 cm spacing produced significantly (P≤0.01) the lower

micro-naire value than 30 cm spacing.

It is evident from the results that interactions of different treatments in early sown crop

were not significant but these interactions between different treatments of cultivar,

spacing and nitrogen fertilizer were found to be significant. These significant effects

might be occurred because cultivar CIM-473 showed better response to each nitrogen rate

resulting lower micronaire values, which indicates good quality fiber.

Fiber strength (tppsi)

Results showed that fiber strength was influenced significantly by the treatments of

cultivars (Table-4.2.32) in late sown crop. Thus, CIM-473 produced significantly fiber

with more strength than CIM-482. It is also observed from the data that spacing and

nitrogen fertilizer treatments did not affect the fibers strength in early as well as late sown

crop. Similar observation was also observed in early sown crop with cultivars, when they

did not influenced the fiber strength.

However, an interaction between cultivar and spacing in early sown crop was found

significant while the cultivar CIM-473 produced significantly lower value of fiber

strength than CIM-482 with 15 cm spacing.

Similarly, interactions between different treatments of cultivars, spacings and nitrogen

fertilizer in late sown crop were also found to be significant. This significant effect

occurred when the cultivar CIM-473 gave significantly the lower value of fiber strength

146
than CIM-482 in treatments where nitrogen was applied at the rate of 100 kg ha-1.

Similarly, CIM-473 gave lower value of fiber strength with 15 cm spacing.

Table-4.2.32 Effect of cultivars, plant spacing and nitrogen fertilizer at different

sowing dates on fiber strength (tppsi)
Treatments May-10 June-01
Nitrogen Cultivars Plant spacing Plant spacing
(kg ha-1) 15 cm 30 cm Means 15 cm 30 cm Means
CIM-473 94.2 95.2 94.7 99.5 96.3 97.9
0
CIM-482 96.3 96.1 96.2 96.9 97.5 97.2
Means 95.3 95.7 95.5 98.2 96.9 97.6
CIM-473 93.2 94.5 93.9 95.1 95.9 95.5
50
CIM-482 95.3 93.9 94.6 95.1 93.9 94.5
Means 94.3 94.2 94.3 95.1 94.9 95.0
CIM-473 95.5 94.0 94.8 92.0 97.4 94.7
100
CIM-482 95.9 96.2 96.0 96.3 93.3 94.8
Means 95.7 95.1 95.4 94.2 95.4 94.8
CIM-473 94.7 95.4 95.1 98.1 97.3 97.7
150
CIM-482 97.3 95.4 96.4 94.3 95.8 95.1
Means 96.0 95.4 95.7 96.2 96.6 96.4
SEs
Nitrogen 0.96 0.60
Cultivars 0.97 0.64
Plant spacing 0.40 0.54
NxC 1.67 21.09
NxS 1.12 0.98
CxS 1.05 0.84
NxCxS 1.85 1.54
LSD (5%)
Nitrogen ns 1.48
Cultivars ns ns
Plant spacing ns ns
NxC ns ns
NxS ns ns
CxS 2.39 ns
NxCxS ns 3.43
Sub effects of different variables
May -10 June- 01
Nitrogen Fiber Fiber Plant Fiber Nitrogen Fiber Fiber Plant Fiber
levels strength Cultivars strength Spacing strength levels strength Cultivars strength spacing strength
(kg ha-1) (tppsi) (tppsi) (cm) -1
(tppsi) (kg ha ) (tppsi) (tppsi) (cm) (tppsi)
0 95.5 CIM-473 94.6 15 95.3 0 97.6a CIM-473 96.5 15 95.9
50 94.3 50 95.0bc
100 95.4 CIM-482 95.8 30 95.1 100 94.8c CIM-482 95.4 30 96.0
150 95.7 150 96.4ab

147
Fiber elongation (% age)

Results showed that fiber elongation was influenced significantly by the treatments of

cultivars (Table-4.2.33).

Table-4.2.33 Effects of cultivars, plant spacing and nitrogen fertilizer at different

sowing dates on fiber elongation (% age)
Treatments May-10 June-01
Nitrogen Cultivars Plant spacing Plant spacing
(kg ha-1) 15 cm 30 cm Means 15 cm 30 cm Means
CIM-473 5.1 5.5 5.3 5.5 5.5 5.5
0
CIM-482 5.6 5.4 5.4 5.4 5.5 5.5
Means 5.4 5.5 5.4 5.5 5.5 5.5
CIM-473 5.4 5.2 5.3 5.0 5.3 5.2
50
CIM-482 5.3 5.5 5.4 5.8 5.6 5.7
Means 5.4 5.4 5.4 5.4 5.5 5.5
CIM-473 5.1 5.1 5.1 5.6 5.6 5.6
100
CIM-482 5.3 5.3 5.3 5.2 5.4 5.3
Means 5.2 5.2 5.2 5.4 5.5 5.5
CIM-473 5.3 5.3 5.3 5.3 5.2 5.3
150
CIM-482 5.2 5.2 5.2 5.5 5.6 5.6
Means 5.3 5.3 5.3 5.4 5.4 5.4
SEs
Nitrogen 0.10 0.03
Cultivars 0.05 0.05
Plant spacing 0.05 0.08
NxC 0.11 0.07
NxS 0.12 0.11
CxS 0.07 0.09
NxCxS 0.16 0.17
LSD (5%)
Nitrogen ns ns
Cultivars 0.10 0.11
Plant spacing ns ns
NxC ns 0.17
NxS ns ns
CxS ns ns
NxCxS 0.36 ns
Sub effects of different variables
May -10 June- 01
Nitrogen Elong- Elong- Plant Elong- Nitrogen Elong- Elong- Plant Elong-
levels ation Cultivars ation Spacing ation levels ation Cultivars ation Spacing ation
(kg ha-1) (%age) (%age) (cm) (%age) (kg ha-1) (%age) (%age) (cm) (%age)
0 5.4 CIM-473 5.3b 15 5.3 0 5.5 CIM-473 5.4b 15 5.4
50 5.4 50 5.5
100 5.2 CIM-482 5.4a 30 5.4 100 5.5 CIM-482 5.5a 30 5.5
150 5.3 150 5.4

148
 CIM-473

5.5
Fibre elongation (%)

4.5

4
0 50 100 150
-1
Nitrgen levels (kg ha )

15cm 30cm
CIM-482

6
Fibre elongation (%)

5.5

4.5

4
0 50 100 150
-1
Nitrogen levels (kg ha )

15cm 30cm

Fig.2.26. Interactive effect of nitrogen, spacing and cultivars on fiber elongation

149
Thus, cultivar CIM-482 produced significantly fiber with higher elongation than CIM-

473 on both early as well as late sowing date (May 10 and June 01). It is observed that

spacings and nitrogen fertilizer treatments did not affect the elongation of fiber. However,

interactions between cultivars, spacings and nitrogen fertilizer were found to be

significant (Fig. 4.2.26). This significant affect might be occurred because the cultivar

CIM-482 gave significantly the higher fiber elongation in treatments where zero nitrogen

was applied with 15 cm plant spacing in early sown crop on May 10. Similarly, the

interactions between cultivars and nitrogen fertilizer in late sown crop were also

significant. Again this significant effect might be occurred because the cultivar CIM-482

produced significantly higher fiber elongation with nitrogen rates of 50 and 150 kg ha-1.

Maturity ratio

Data indicated that fiber maturity was influenced significantly by the cultivars (Table-

4.2.34) in late sown crop. The cultivar CIM-482 gave significantly (P≤0.01) higher

percentage of fiber maturity than CIM-473. It is observed from the results that nitrogen

fertilizer increment significantly the maturity. The higher nitrogen rates (100 and 150 kg

ha-1) produced significantly lower values of maturity than lower rates of nitrogen

fertilizer (i.e. zero and 50 kg ha-1) in late sown crop on June 01. It is obvious from the

results that maturity was affected significantly by the plant spacing on both early and late

sowing date (May 10 and June 01). The plant spacing of 15 cm produced significantly the

higher maturity percentage than 30 cm spacing.

The interactions between cultivars, spacings and nitrogen fertilizer were found to be non

significant on both sowing dates (May 10 and June 01).

150
 Table-4.2.34 Effect of cultivars, plant spacing and nitrogen fertilizer at different
sowing dates on maturity ratio
Treatments May-10 June-01
Nitrogen Cultivars Plant spacing Plant spacing
(kg ha-1) 15 cm 30 cm Means 15 cm 30 cm Means
CIM-473 1.01 1.01 1.01 1.06 1.03 1.05
0
CIM-482 1.06 1.05 1.06 1.11 1.09 1.10
Means 1.04 1.03 1.04 1.09 1.06 1.08
CIM-473 1.02 1.02 1.02 1.06 1.04 1.05
50
CIM-482 1.06 1.01 1.04 1.11 1.10 1.11
Means 1.04 1.02 1.03 1.09 1.07 1.08
CIM-473 1.01 0.99 1.00 1.07 1.04 1.06
100
CIM-482 1.03 1.02 1.03 1.10 1.06 1.08
Means 1.02 1.01 1.02 1.09 1.05 1.07
CIM-473 1.02 1.01 1.02 1.04 1.02 1.03
150
CIM-482 1.02 1.00 1.01 1.10 1.06 1.08
Means 1.02 1.01 1.02 1.07 1.04 1.06
SEs
Nitrogen 0.02 0.00
Cultivars 0.01 0.00
Plant spacing 0.01 0.01
NxC 0.03 0.01
NxS 0.02 0.01
CxS 0.02 0.01
NxCxS 0.03 0.01
LSD (5%)
Nitrogen ns 0.00
Cultivars ns 0.01
Plant spacing 0.01 0.01
NxC ns ns
NxS ns ns
CxS ns ns
NxCxS ns ns
Sub effects of different variables
May -10 June- 01
Nitrogen Plant Nitrogen Plant
Maturity Maturity Maturity Maturity Maturity Maturity
levels Cultivars Spacing levels Cultivars Spacing
ratio ratio ratio ratio ratio ratio
(kg ha-1) (cm) (kg ha-1) (cm)
0 1.04 CIM-473 1.01 15 1.03a 0 1.08a CIM-473 1.05b 15 1.09a
50 1.03 50 1.08a
100 1.02 CIM-482 1.04 30 1.02b 100 1.07b CIM-482 1.09a 30 1.06b
150 1.02 150 1.06c

Brightness (Rd)

Brightness percentage of cotton cultivars influenced significantly on early as well as late

sown crops (Table-4.2.35).

151
 Table-4.2.35 Effect of cultivars, plant spacing and nitrogen fertilizer at different
sowing dates on brightness (Rd)
Treatments May-10 June-01
Nitrogen Cultivars Plant spacing Plant spacing
(kg ha-1) 15 cm 30 cm Mean 15 cm 30 cm Means
s
CIM-473 74.6 75.9 75.3 76.9 76.5 76.7
0
CIM-482 73.7 73.3 73.5 74.7 75.7 75.2
Means 74.2 74.6 74.4 75.8 76.1 76.0
CIM-473 75.8 75.0 75.4 76.2 76.6 76.4
50
CIM-482 73.3 73.6 73.5 75.5 75.9 75.7
Means 74.6 74.3 74.5 75.9 76.3 76.1
CIM-473 75.8 76.2 76.0 76.9 75.7 76.3
100
CIM-482 74.4 73.5 74.0 74.1 74.8 74.5
Means 75.1 74.9 75.0 75.5 75.3 75.4
CIM-473 76.5 76.6 76.6 76.9 76.6 76.8
150
CIM-482 73.9 73.5 73.7 75.2 76.1 75.7
Means 75.2 75.1 75.2 76.1 76.4 76.3
SEs
Nitrogen 0.59 0.10
Cultivars 0.53 0.14
Plant spacing 0.41 0.09
NxC 0.95 0.22
NxS 0.83 0.16
CxS 0.67 0.16
NxCxS 1.26 0.28
LSD (5%)
Nitrogen ns 0.25
Cultivars 1.22 0.31
Plant spacing ns 0.19
NxC ns ns
NxS ns ns
CxS ns 0.36
NxCxS ns 0.63
Sub effects of different variables
May -10 June- 01
Nitrogen Bright- Bright Plant Bright Nitrogen Bright- Bright Plant Bright
levels ness Cultivars -ness Spacing ness levels ness Cultivars -ness Spacing -ness
(kg ha-1) (Rd) (Rd) (cm) (Rd) (kg ha-1) (Rd) (Rd) (cm) (Rd)
0 74.4 CIM-473 75.8a 15 74.8 0 76.0b CIM-473 76.6a 15 75.8b
50 74.5 50 76.1ab
100 75.0 CIM-482 73.7b 30 74.7 100 75.4c CIM-482 75.3b 30 76.0a
150 75.2 150 76.3a

152
 CIM-473

80

78
Brightness (% Rd)

76

74

72

70
0 50 100 150
-1
Nitrogen levels (kg ha )

15cm 30cm

0 50 100
-1
Nitrogen levels kg ha

15cm 30cm

#24b

15cm 30cm
0 74.7 75.7
50 75.5 75.9
100 74.1 74.8
150 75.2 76.1

CIM-482

Fig.4.2.27 80 of nitrogen, spacing and cultivars on brightness

Interactive effect

(Rd)

153
Cultivar CIM-473 gave produced significantly fiber of higher brightness than cultivar

CIM-482 on both sowing dates. However, crop sown early on May 10 and plant spacing

did not affect the brightness of the fiber. Thus, significantly (P≤0.05) higher brightness of

76.0% was observed with 30 cm spacing and the lower brightness of 75.8% with narrow

spacing (15 cm) when crop sown late on June 01. While, in early sown crop higher

nitrogen rates (i.e. 100 and 150 kg ha-1) tended to produce higher brightness fiber but

differences were not significant statistically. The highest rate of nitrogen fertilizer (150

kg ha-1) produced significantly (P≤0.05) fiber of higher brightness than zero nitrogen

application when crop sown late on June 01.

It is evident from the results that interactions between nitrogen and spacing were

significant when sown late. Similarly, the interactions of cultivars, spacings and nitrogen

fertilizer were also found to be significant (Fig. 4.2.27). Thus, significant effect might be

occurred that cultivar CIM-473 showed better response to nitrogen application with both

spacings resulted higher brightness of the fiber in late sown crop. However, all

interactions of cultivars, spacings and nitrogen fertilizer were found to be non-significant

when crop sown early on May 10.

Yellowness (+b)

Results showed that that different treatments of cultivars, plant spacings and nitrogen

application did not affect the yellowness when crop sown early on May 10 (Table-

4.2.36). However, when crop sown late on June 01, cultivar and nitrogen fertilizer

influenced significantly the yellowness .Cultivar CIM-482 showed significantly (P≤0.01)

higher yellowness of 9.2% while lower yellowness of 8.8% with CIM-473. It is observed

that nitrogen fertilizer when applied at the rate of 50 kg ha-1 showed significantly higher

yellowness and all other nitrogen rates did not affect the yellowness.

154
Table-4.2.36 Effect of cultivars, plant spacing and nitrogen fertilizer at different
sowing dates on yellowness (+b)
Treatments May-10 June-01
Nitrogen Cultivars Plant spacing Plant spacing
(kg ha-1) 15 cm 30 cm Means 15 cm 30 cm Means
CIM-473 8.6 8.6 8.6 8.8 8.4 8.6
0
CIM-482 8.8 8.7 8.8 9.2 9.1 9.2
Means 8.7 8.7 8.7 9.0 8.8 8.9
CIM-473 8.7 8.9 8.8 8.6 9.3 9.0
50
CIM-482 8.4 8.4 8.4 9.2 9.2 9.2
Means 8.6 8.7 8.6 8.9 9.3 9.1
CIM-473 8.8 8.6 8.7 8.8 8.6 8.7
100
CIM-482 8.5 8.4 8.5 9.3 9.3 9.3
Means 8.7 8.5 8.6 9.1 9.0 9.0
CIM-473 8.5 8.8 8.7 8.9 8.7 8.8
150
CIM-482 8.6 8.8 8.7 8.9 9.3 9.1
Means 8.6 8.8 8.7 8.9 9.0 9.0
SEs
Nitrogen 0.17 0.03
Cultivars 0.12 0.06
Plant spacing 0.07 0.07
NxC 0.23 0.09
NxS 0.19 0.11
CxS 0.14 0.09
NxCxS 0.27 0.17
LSD (5%)
Nitrogen ns 0.08
Cultivars ns 0.14
Plant spacing ns ns
NxC ns ns
NxS ns 0.23
CxS ns ns
NxCxS ns 0.37
Sub effects of different variables
May -10 June- 01
Nitrogen Yellow- Yellow- Plant Yellow- Nitrogen Yellow- Yellow- Plant Yellow-
levels ness Cultivars ness Spacing ness levels ness Cultivars ness Spacing ness
(kg ha-1) (+b) (+b) (cm) (+b) (kg ha-1) (+b) (+b) (cm) (+b)
0 8.7 CIM-473 8.7 15 8.7 0 8.9c CIM-473 8.8b 15 9.0
50 8.6 50 9.1a
100 8.6 CIM-482 8.6 30 8.7 100 9.0b CIM-482 9.2a 30 9.0
150 8.7 150 9.0b

155
 June-01

10

Yellowness (+b)

8
15cm 30cm
Plant spacing (cm)

CIM-473 CIM-482

Fig.4.2.28. Interactive effect of spacing and cultivars on yellowness (+b)

It is evident from the results that interactions between cultivars and plant spacing were

significant (Fig.4.2.28) when crop sown late on June 01. Similarly interactions of

nitrogen fertilizer, cultivars and spacings were also found to be significant. These

significant effects might be occurred that the growth of cultivar CIM-482 prolonged with

nitrogen application that resulted higher yellowness of cotton fiber. However, other

interactions between different treatments were found to be non-significant.

Crop growth rate (gm-2 day-1)

Table (4.2.37-38) shows that crop growth rate was influenced significantly by different

treatments of cultivars, spacing and nitrogen fertilizer. Thus, cultivar CIM-482 increased

significantly (P≤0.05) crop growth rate at early growth stage (50 DAS), while later on

CIM-473 gave significantly higher growth rate throughout the crop growth when sown

early on May 10. Cultivars sown on June 01 showed a similar trend until 100 DAS like

that of sown early but at the final harvest CIM-482 gave higher growth rate. It is also

156
clear from the results that each increment of nitrogen fertilizer increased significantly

(P≤0.05) growth rate during early growth stages (50 and 100 DAS) while, at the final

harvest each decrease in nitrogen reduced significantly (P≤0.05) the growth rate on both

sowing dates. It is interesting that narrow spacing increased significantly (P≤0.05) the

growth rate throughout the crop growth on both the sowing dates.

The interactions between cultivars and nitrogen were significant at later stages of growth

when sown on May 10 because CIM-473 with each increment of nitrogen produced

higher growth rate and produced a similar trend (100 DAS) when sown on June 01,

however, here at 150 DAS CIM-482 gave higher growth rate with each decrease in

nitrogen. However, interactions between nitrogen and spacing were significant

throughout the crop growth on both the sowing dates. These significant affect might be

occurred because narrow spacing significantly produced higher crop growth rate with

each increment of nitrogen. Similarly the interaction between cultivars and spacing were

also found to be significant on both the sowing dates these may because that at 100 DAS,

CIM-473 produced higher growth rate with each spacing while later on CIM-473 gave

higher growth rate with 30 cm spacing and CIM-482 with 15 cm.

However the interactions between nitrogen, cultivars and spacing were also found

significant at final growth stages on both sowing dates. These were because that CIM-473

with both the spacings produced higher growth rate with each increment of nitrogen at

100 DAS while 150 DAS CIM-482 gave higher growth rate with narrow and CIM-473

with wider spacing. (Fig. 4.2. 29-37).

157
 Table-4.2.37 Effect of cultivars sown on May 10, plant spacing and nitrogen
fertilizer on crop growth rate (gm-2 day-1).
50 DAS 100 DAS 150 DAS
Nitrogen Spacing (cm) Spacing (cm) Spacing (cm)
(Kg ha-1)
Cultivars
15 30 Means 15 30 Means 15 30 Means
CIM-473 2.25 1.71 1.98 5.72 3.40 4.56 4.04 4.74 4.39
0 CIM-482 2.31 1.80 2.06 4.85 3.21 4.03 4.13 4.48 4.31
Means 2.28 1.76 2.02 5.29 3.31 4.30 4.09 4.61 4.35
CIM-473 2.37 1.87 2.12 8.59 6.88 7.74 3.26 3.43 3.35
50 CIM-482 2.48 1.98 2.23 7.49 5.18 6.34 3.29 3.27 3.28
Means 2.43 1.93 2.18 8.04 6.03 7.04 3.28 3.35 3.32
CIM-473 2.48 2.13 2.31 11.68 8.81 10.25 2.19 2.37 2.28
100 CIM-482 2.61 2.22 2.42 9.38 7.70 8.54 2.44 1.99 2.22
Means 2.55 2.18 2.37 10.53 8.26 9.40 2.32 2.18 2.25
CIM-473 2.68 2.26 2.47 13.08 10.57 11.83 1.97 1.04 1.51
150 CIM-482 2.72 2.40 2.56 11.31 9.98 10.65 2.27 1.00 1.64
Means 2.70 2.33 2.52 12.20 10.28 11.24 2.12 1.02 1.57
SEs
Nitrogen 0.01 0.01 0.01
Cultivars 0.02 0.01 0.01
Plant spacing 0.01 0.01 0.01
NxC 0.03 0.01 0.02
NxS 0.02 0.02 0.02
CxS 0.02 0.02 0.02
NxCxS 0.04 0.03 0.03
LSD (5%)
Nitrogen 0.03 0.01 0.03
Cultivars 0.04 0.02 0.02
Plant spacing 0.03 0.03 0.03
NxC ns 0.03 0.04
NxS 0.06 0.04 0.05
CxS ns 0.03 0.07
NxCxS ns 0.06 0.07
Sub effects of different variables
Crop growth rate (gm-2 day-1)
Nitrogen Plant
50 100 150 50 100 150 50 100 150
levels Cultivars Spacing
DAS DAS DAS DAS DAS DAS DAS DAS DAS
(kg ha-1) (cm)
0 2.02d 4.30d 4.35a
50 2.18c 7.04c 3.07b CIM-473 2.22b 8.60a 2.88a 15 2.49a 9.02a 2.83a
100 2.37b 9.40b 2.25c CIM-482 2.32a 2.78b 2.66b 30 2.05b 6.97b 2.72b
150 2.52a 11.24a 1.42d

158
Table-4.2.38 Effect of cultivars sown on June 01, plant spacing and nitrogen
fertilizer on crop growth rate (gm-2 day-1).
Nitrogen 50 DAS 100 DAS 150 DAS
(Kgha-1) Cultivars Spacing (cm) Spacing (cm) Spacing (cm)
15 30 Means 15 30 Means 15 30 Means
CIM-473 2.21 1.69 1.95 5.90 3.47 4.69 3.86 4.56 4.21
0 CIM-482 2.27 1.78 2.03 4.89 3.06 3.98 4.14 4.70 4.42
Means 2.24 1.74 1.99 5.40 3.27 4.34 4.00 4.63 4.32
CIM-473 2.32 1.85 2.09 8.78 6.54 7.66 3.27 3.87 3.57
50 CIM-482 2.47 1.96 2.22 7.38 4.71 6.05 2.58 3.93 3.26
Means 2.40 1.91 2.16 8.08 5.63 6.86 2.93 3.90 3.42
CIM-473 2.44 2.14 2.29 11.34 8.78 10.06 2.57 2.34 2.46
100 CIM-482 2.61 2.18 2.40 8.90 7.61 8.26 3.07 2.27 2.67
Means 2.53 2.16 2.35 10.12 8.20 9.16 2.82 2.31 2.57
CIM-473 2.67 2.25 2.46 12.77 10.67 11.72 1.87 1.00 1.44
150 CIM-482 2.65 2.38 2.52 10.81 9.54 10.18 2.74 0.83 1.79
Means 2.66 2.32 2.49 11.79 10.11 10.95 2.31 0.92 1.62
SEs
Nitrogen 0.01 0.02 0.01
Cultivars 0.01 0.01 0.01
Plant spacing 0.01 0.01 0.01
NxC 0.02 0.03 0.02
NxS 0.02 0.03 0.02
CxS 0.02 0.02 0.02
NxCxS 0.03 0.04 0.03
LSD (5%)
Nitrogen 0.03 0.05 0.02
Cultivars 0.02 0.03 0.02
Plant spacing 0.02 0.03 0.03
NxC ns 0.06 0.04
NxS 0.05 0.06 0.05
CxS ns 0.04 0.04
NxCxS ns 0.07 0.08
Sub effects of different variables
Crop growth rate (gm-2 day-1)
Nitrogen Plant
50 100 150 50 100 150 50 100 150
levels Cultivars Spacing
-1 DAS DAS DAS DAS DAS DAS DAS DAS DAS
(kg ha ) (cm)
0 1.99d 4.34d 4.32a CIM-473 2.20b 8.53a 2.92b 15 2.46a 8.85a 3.02a
50 2.16c 6.86c 3.42b
100 2.35b 9.16b 2.57c CIM-482 2.29a 7.12b 3.04a 30 2.03b 6.80b 2.94b
150 2.49a 10.95a 1.62d

159
 May 10

Crop Growth Rate 50 DAS

5.00

4.00

3.00

2.00

1.00

0.00
0 50 100 150
Nitrogen Level (kg ha-1)

15cm 30cm

Fig. 4.2.29 Interactive effect of nitrogen and plant spacing on crop growth rate
(gm-2 day-1) at 50 DAS

June 01
Crop Growth Rate 100 DAS

15.00

12.00

9.00

6.00

3.00

0.00
15cm 30cm
Plant Spacing (cm)

CIM-473 CIM-482

Fig. 4.2.30 Interactive effect of plant spacing and cultivars on crop growth rate
(gm-2 day-1) at 100 DAS

160
 June 01

Crop Growth Rate 150 DAS

5.00

4.00

3.00

2.00

1.00
0 50 100 150
-1
Nitrogen Level (kg ha )

CIM-473 CIM-482

Fig. 4.2.31 Interactive effect of nitrogen and cultivars on crop growth rate (gm-2
day-1) at 150 DAS

June 01
Crop Growth Rate 150 DAS

5.00

4.00

3.00

2.00

1.00

0.00
0 50 100 150
-1
Nitrogen Level (kg ha )

15cm 30cm

Fig. 4.2.32 Interactive effect of nitrogen and plant spacing on crop growth rate
(gm-2 day-1) at 150 DAS

161
 CIM-473
Crop Growth Rate 100 DAS

14.00
12.00
10.00
8.00
6.00
4.00
2.00
0.00
0 50 100 150
Nitrogen levels (kg ha-1)

15 cm 30 cm

CIM-482
Crop Growth Rate 100

12.00
10.00
8.00
DAS

6.00
4.00
2.00
0.00
0 50 100 150
-1
Nitrogen levels (kg ha )

15 cm 30 cm

Fig. 4.2.33 Interactive effect of nitrogen, plant spacing and cultivars on crop
growth rate (gm-2 day-1) at 100 DAS (May-10)

162
 CIM-473

5.00
Crop Growth Rate 150

4.00
3.00
DAS

2.00
1.00
0.00
0 50 100 150
-1
Nitrogen levels (kg ha )

15 cm 30 cm

CIM-482

5.00
Crop Growth Rate 150

4.00
3.00
DAS

2.00
1.00
0.00
0 50 100 150
-1
Nitrogen level (kg ha )

15 cm 30 cm

Fig. 4.2.34 Interactive effect of nitrogen plant spacing and cultivars on crop
growth rate (gm-2 day-1) at 150 DAS (May-10)

163
 CIM-473

14.00
Crop Growth Rate 100

12.00
10.00
8.00
DAS

6.00
4.00
2.00
0.00
0 50 100 150
-1
Nitrogen levls (Kg ha )

15 cm 30 cm

CIM-482

12.00
Crop Growth Rate 100

10.00
8.00
DAS

6.00
4.00
2.00
0.00
0 50 100 150
Nitrogen level (Kg ha-1)

15 cm 30 cm

Fig.4.2.35 Interactive effect of nitrogen plant spacing and cultivars on crop

growth rate (gm-2 day-1) at 100 DAS (June-01)

164
 CIM-473

5.00
Crop Growth Rate 150 4.00
3.00
DAS

2.00
1.00
0.00
0 50 100 150
-1
Nitrogen level (Kg ha )

15 cm 30 cm

CIM-482

5.00
Crop Growth Rate 150

4.00
3.00
DAS

2.00
1.00
0.00
0 50 100 150
-1
Nitrogen level (Kg ha )

15 cm 30 cm

Fig. 4.2.36 Interactive effect of nitrogen plant spacing and cultivars on crop
growth rate (gm-2 day-1) at 150 DAS (June-01)

165
 June 01

4.00
Crop Growth Rate 150 DAS

3.00

2.00
15cm 30cm
Plant Spacing (cm)
CIM-473 CIM-482

Fig. 4.2.37 Interactive effect of plant spacing and cultivars on crop growth rate
(gm-2 day-1) at 150 DAS

Relative growth rate (g g-1 day-1)

Results showed that relative growth rate in Table (4.2.39-40) influenced significantly by

different treatments of cultivars, nitrogen and spacing. Cultivar CIM-482 increased

significantly (P≤0.05) relative growth rate than CIM-473 at early harvest on May 10, and

at early and final harvest on crop sown June 01 while, at (100 DAS) CIM-473 increased

significantly relative growth rate than CIM-482 on both sowing dates. Results showed

that relative growth rate was increased significantly with each increment of nitrogen

(P≤0.05) at early growth stages on both sowing dates. While at final harvest relative

growth rate significantly (P≤0.05) decreased with each increment of nitrogen on both

sowing dates. It is observed that narrow spacing increased significantly (P≤0.05) relative

growth rate than wider spacing at early growth stages and at the final harvest (150 DAS)

166
 wider spacing produce significantly higher relative growth rate than narrow spacing with

lower nitrogen levels (0 and 50 kg ha-1

Table-4.2.39 Effect of cultivars sown on May 10, plant spacing and nitrogen
fertilizer on relative growth rate (g g-1 day-1).
50 DAS 100 DAS 150 DAS
Nitrogen
Cultivars Spacing (cm) Spacing (cm) Spacing (cm)
(Kgha-1)
15 30 Means 15 30 Means 15 30 Means
CIM-473 *4.10 3.86 3.98 1.10 0.95 1.03 0.36 0.57 0.47
0 CIM-482 4.13 3.91 4.02 0.98 0.89 0.94 0.40 0.56 0.48
Means 4.12 3.89 4.00 1.04 0.92 0.98 0.38 0.57 0.48
CIM-473 4.15 3.94 4.05 1.33 1.34 1.34 0.23 0.29 0.26
50 CIM-482 4.19 3.99 4.09 1.21 1.11 1.16 0.18 0.33 0.26
Means 4.17 3.97 4.07 1.27 1.23 1.25 0.21 0.31 0.26
CIM-473 4.19 4.05 4.12 1.51 1.42 1.47 0.13 0.17 0.15
100 CIM-482 4.23 4.09 4.16 1.32 1.30 1.31 0.16 0.16 0.16
Means 4.21 4.07 4.14 1.42 1.36 1.39 0.15 0.17 0.16
CIM-473 4.25 4.11 4.18 1.54 1.51 1.53 0.10 0.07 0.09
150 CIM-482 4.27 4.16 4.22 1.43 1.43 1.43 0.13 0.03 0.08
Means 4.26 4.14 4.20 1.49 1.47 1.48 0.12 0.05 0.09
SEs
Nitrogen 0.01 0.01 0.02
Cultivars 0.01 0.01 0.01
Plant spacing 0.02 0.02 0.01
NxC 0.01 0.02 0.02
NxS 0.03 0.02 0.02
CxS 0.02 0.02 0.01
NxCxS 0.04 0.04 0.03
LSD (5%)
Nitrogen 0.02 0.03 0.04
Cultivars 0.01 0.02 ns
Plant spacing 0.04 0.03 0.03
NxC ns ns ns
NxS ns ns 0.05
CxS ns ns ns
NxCxS ns ns ns
Sub effects of different variables
Relative growth rate (g day-1)
Nitrogen Plant
50 100 150 50 100 150 50 100 150
levels Cultivars Spacing
DAS DAS DAS DAS DAS DAS DAS DAS DAS
(kg ha-1) (cm)
0 4.00d 0.98d 0.48a CIM-473 4.08b 1.34a 0.24 15 4.19a 1.31a 0.22b
50 4.07c 1.25c 0.26b
100 4.14b 1.39b 0.16c CIM-482 4.12a 1.21b 0.25 30 4.02b 1.25b 0.28a
150 4.20a 1.48a 0.09d
*All values are multiplied by 100 for analysis purpose.

167
Table-4.2.40 Effect of cultivars sown on June 01, plant spacing and nitrogen
fertilizer on relative growth rate (g g-1 day-1).
50 DAS 100 DAS 150 DAS
Nitrogen
Cultivars Spacing (cm) Spacing (cm) Spacing (cm)
(Kgha-1)
15 30 Means 15 30 Means 15 30 Means
CIM-473 *4.09 3.85 3.97 1.13 0.97 1.05 0.34 0.55 0.45
0 CIM-482 4.11 3.90 4.01 0.91 0.87 0.89 0.40 0.59 0.50
Means 4.10 3.88 3.99 1.02 0.92 0.97 0.37 0.57 0.47
CIM-473 4.13 3.93 4.03 1.36 1.31 1.34 0.22 0.33 0.28
50 CIM-482 4.18 3.98 4.08 1.20 1.07 1.14 0.20 0.40 0.30
Means 4.16 3.96 4.06 1.28 1.19 1.24 0.21 0.37 0.29
CIM-473 4.17 4.06 4.12 1.50 1.42 1.46 0.15 0.17 0.16
100 CIM-482 4.23 4.07 4.15 1.29 1.31 1.30 0.21 0.18 0.20
Means 4.20 4.07 4.14 1.40 1.37 1.38 0.18 0.18 0.18
CIM-473 4.25 4.10 4.18 1.52 1.52 1.52 0.10 0.07 0.09
150 CIM-482 4.25 4.15 4.20 1.41 1.14 1.28 0.16 0.06 0.11
Means 4.25 4.13 4.19 1.47 1.33 1.40 0.13 0.07 0.10
SEs
Nitrogen 0.02 0.11 0.01
Cultivars 0.01 0.08 0.01
Plant spacing 0.02 0.08 0.01
NxC 0.02 0.16 0.02
NxS 0.03 0.16 0.02
CxS 0.02 0.12 0.02
NxCxS 0.04 0.23 0.03
LSD (5%)
Nitrogen 0.04 ns 0.02
Cultivars 0.02 0.19 0.03
Plant spacing 0.03 0.17 0.03
NxC ns ns ns
NxS ns ns 0.05
CxS ns ns ns
NxCxS ns ns ns
Sub effects of different variables
Relative growth rate (g g day-1)
Nitrogen Plant
50 100 150 50 100 150 50 100 150
levels Cultivars Spacing
DAS DAS DAS DAS DAS DAS DAS DAS DAS
(kg ha-1) (cm)
0 3.99d 1.00 0.47a CIM-473 4.08b 1.34 0.25b 15 4.18a 1.31a 0.22b
50 4.06c 1.24 0.29b
100 4.14b 1.38 0.18c CIM-482 4.11a 1.20 0.28a 30 4.01b 1.24b 0.30a
150 4.19a 1.47 0.10d
*All values are multiplied by 100 for analysis purpose.

168
 May-10

0.60
Crop Growth Rate 150

0.50
0.40
DAS

0.30
0.20
0.10
0.00
0 50 100 150
Nitrogen level (Kg ha-1)

15 cm 30 cm

Fig.4.2.38 Interactive effect of nitrogen and plant spacing on relative growth

rate (g g-1 day-1) at 150 DAS

June-01
Relative Growth Rate 150

0.80
0.70
0.60
0.50
DAS

0.40
0.30
0.20
0.10
0.00
0 50 100 150
-1
Nitrogen level (Kg ha )

15 cm 30 cm

Fig.4.2.39 Interactive effect of nitrogen and plant spacing on relative growth

rate (g g-1 day-1) at 150 DAS

169
Again it is evident from the results that interaction between nitrogen and spacing were

found to be significant at final harvest (Fig. 4.2.38-39). These significant affects at

maturity might because that the treatments where nitrogen was applied either narrow or

wider spacing showed significant decrease in growth rate than zero nitrogen application

treatment.

2.2.3 DISCUSSION

Nitrogen is an integral part of chlorophyll which is the primarily observer of light energy

needed for photosynthesis. Thus, an adequate supply of nitrogen is associated with high

photosynthetic activities, vigorous vegetative growth and a dark green colour. However,

the uncertainty of available nitrogen in the soil for optimal cotton yield under different

environmental conditions is due to the indeterminate growth of cotton plant and the

complexity of nitrogen in the soils and therefore, the use of optimal nitrogen is very

important for cotton and even more for cotton grown in narrow spacing as nitrogen have

to be adjusted to avoid excessive plant growth and delay maturity and to optimize fiber

quality (Boquet, 2005; Pettigrew, et al., 2006).

Nitrogen is considered one of the major essential nutrients for plant growth and in this

experiment application of nitrogen fertilizer produced a clear observation for growth and

seed cotton yield of the crop. Thus, each increment of nitrogen fertilizer in both the

cultivars with each spacing produced significantly higher seed cotton yield, however, the

wider spacing (30 cm) treatments reduced significantly the yields in both the cultivars.

Similar findings are also found by other researchers (Anwar, et al., 2003;Marsh, et al.,

2000;Parsad, et al., 2000;Goday, et al., 1994; Brar, et al., 1993; Elayan, 1992;

McConnell, et al., 1993) who reported that the highest seed cotton yield was obtained

170
with the highest nitrogen rates. It is also observed that nitrogen gave a better response to

plant height as each increment of nitrogen produced taller plants on both sowing dates

and thus, significantly the tallest plants were found with the highest nitrogen rate of 150

kgha-1 A few other investigations have also been reported by other scientists that final

plant height was significantly increased with each additional increase in nitrogen

fertilizer and the highest plant height was observed with the highest nitrogen rate of 151

kgha-1 (Clawson, et al.,2006;Fritchi, et al.,2003 ; Boquet, and Breitenbeck 2000; Brar, et

al., 1993; Koli and Morill,1976).

It is evident from the results that nitrogen application at the rate of 150 kgha-1 produced

higher number of intact fruits, bolls plant-1, and boll weight alongwith higher vegetative

and reproductive dry matter at final harvest. Low nitrogen fertility is associated with

several alterations in cotton crop development including slower growth and smaller

leaves, greater root shoot ratio, increased earliness and greater shedding percentage

(Radin and Mauney, 1986). Thus, it is clear from the results that the treatments where

nitrogen was not applied to the soil enhanced the earliness of cotton cultivars that

promoted shedding percentage which led to the lowest seed cotton yield.

The potential of a variety could be realized when sown at the proper spacing, optimum

time and judicious use of nutrients. In this regard, researchers are of different opinion,

some have advocated for narrow spacing and some say no impact of spacing on yield of

cotton. It is obvious that spacing between rows and plants count a lot for proper growth,

better aeration and better pest control management. However, investigations briefly

concurred that both the spacings in each cultivar showed that each increment of nitrogen

fertilizer are significantly increased the seed cotton yield in both sowing dates (i.e. May

171
10 and June 01). Thus, narrow spacing of 15 cm gave a significant increase with each

increment of nitrogen than wider spacing (30 cm) treatments on both sowing dates. .

Similar responses of cotton to spacing are found by other researchers and they reported

that the highest seed cotton yields were observed in narrow spaced crop (Palomo, et al.,

2000; Ramana, et al., 2000 Sheker, et al., 1999; Gerik, et al., 1998; Devi, et al., 1995).

Results showed that narrow spacing influenced significantly the growth and yield traits of

cotton in the form of an increase in plant height, nodes per plant, inter-nodal distance,

intact fruits, boll number and reproductive dry matter that resulted higher seed cotton

yield. Similar findings are also reported by Clawson, et al., (2006) Bednarz, et al., (2006)

Boquet, et al., (2005); Bednarz, et al., (2000); Gunnaway, et al., (1995). On the other

side, the wider spacing (30 cm) gave the heaviour seed index (100 seed weight) and boll

weight but, reduced the number of bolls per unit area which resulted in lower seed cotton

yield These results are supported by Boquet, et al., (2005) who reported that an increase

in plant density significantly decreased individual plant weight.

It is obvious that the seed cotton yield per unit area is influenced by cultivars, nutrient

management and sowing time. Selected varieties were evaluated in a system of different

sowing times and plant populations. However, in experiment II, both the cultivars

showed similar observation like that of the last year studies and thus, the crop sown early

on May 10 produced a significant interaction of cultivars and plant spacing. These

significant effects might be occurred because both the cultivars gave significant increase

in yield with narrow spacing of 15 cm than wider spacing (30 cm). Similarly cultivars

when sown late on June 01 tended to produce higher yield with narrow spacing but

differences were not significant statistically. However, cultivar CIM- 473 produced

significantly higher seed cotton yield on each sowing date with both spacing than CIM -

482.

172
However, CIM- 482 bearing taller plants, more number of nodes, higher shedding

percentage, higher seed index and boll weight resulting more vegetative dry matter.

While CIM-473 bearing higher number of intact fruits, boll number and higher

reproductive dry matter resulted higher seed cotton yields. Other researchers who studied

the impact of nitrogen with cotton cultivars observed that cultivars showed significant

results at nitrogen levels (Mc Connel, et al., 2000; Pazzetti, et al., 1999).

173
4.3 Experiment– III

Title-Effect of plant spacing and nitrogen levels on cotton

productivity
The experiment was conducted at the Central Cotton Research Institute, Multan, Pakistan

during 2006 on a silt loam soil having; pH 8.06, EC;2.67dSm-1 and organic matter 0.84%.

The objective of this study was to determine the cotton productivity to various levels of

nitrogen and plant spacing.

Experimental Design

The experiment was replicated thrice and laid out in randomized complete block design

with split plot arrangements with two factors.

Treatments

Nitrogen levels

N1 0

N2 100

N3 150

Plant Spacings

S1 15 cm

S2 30 cm

4.3.1 Materials and Methods

The experiment was conducted to study the response of cotton cultivar to various levels

of nitrogen application. Cotton cultivar CIM-473 was planted on May 10 on bed furrow

75 cm apart at 15 and 30 cm plant to plant distance with three levels of nitrogen fertilizer

174
i.e. 0, 100 and 150 kg ha-1. The planting was done manually on bed furrows by dibbling

method. Nitrogen levels were kept in main plots and plant spacing in the sub plots. Three

nitrogen levels (0, 100 and 150 kg ha-1) were applied in three split doses on June 01, July

05 and August 15. Cultural practices such as inter-culturing, irrigation and plant

protection were adopted as per requirement of the crop. Analytical results of the soil

samples collected at pre planting and after the harvest of crop are given in Table-5.

Table-5 Chemical analysis of the experimental site (2006)

Before sowing After harvesting
Characteristics Depth (cm) Depth (cm)
0-15 15-30 0-15 15-30
-1
EC dSm 2.63 2.70 2.60 2.70

Soil pH (1:1) 8.01 8.10 8.01 8.04

Organic Matter (%) 0.85 0.83 0.89 0.85

NO3-N (mg kg-1) 5.57 4.51 5.70 4.66

NaHO3-P (mg kg-1) 13.4 11.8 12.6 11.3

NH4OAC–K (mg kg-1) 120.0 116.0 114.0 105.0

4.3.2 Results
Plant height (cm)

Data presented in the Table (4.3.1) showed that each increment of nitrogen fertilizer

tended to produce taller plants at the early and final harvest ( 50 and 150 DAS ) but the

differences were not significant statistically. However, 100 and 150 kg nitrogen ha-1

treatments produce significant (P≤0.01) taller plants than zero kg nitrogen ha-1 at the

harvest of (100 DAS). Similarly narrow spacing treatments tended to produce taller

175
plants than wider spacing treatments through out the crop growth but the differences were

not significant statistically.

The interactions between nitrogen and plant spacing were found to be non significant

through out the crop growth in all the growth stages.

Table 4.3.1 Effect of nitrogen fertilizer and plant spacing on plant height (cm)
50 DAS 100 DAS 150 DAS
Nitrogen
Spacing (cm) Spacing (cm) Spacing (cm)
(Kg ha-1)
15 30 Means 15 30 Means 15 30 Means
0 64.0 63.0 63.5 84.0 82.0 83.0b 105.0 104.0 104.5
100 67.8 66.2 67.0 91.0 87.0 89.0a 109.0 108.0 108.5
150 69.0 69.0 69.0 95.0 91.0 93.0a 114.0 112.0 113.0
Means 66.9 66.1 90.0 86.7 109.3 108.0
SEs
Nitrogen 1.65 1.46 2.96
Plant spacing 1.63 2.58 3.25
NxS 2.82 4.47 5.63
LSD (5%)
Nitrogen ns 4.07 ns
Plant spacing ns ns ns
NxS ns ns ns
Nitrogen-N Plant spacing- S

Nodes per plant

Observation like that of plant height was also appeared for the nodes per plant. It is

evident from the results that each increment of nitrogen fertilizer tended to gave higher

number of nodes at early growth stage (50 DAS) and final growth stage (150 DAS)

except (100 and 150 kg nitrogen ha-1) at early growth stage which produce same number

of nodes per plant but the differences were not significant statistically. However, 150 kg

nitrogen ha-1 treatments produced significantly (P≤0.05) more number of nodes than zero

176
kg nitrogen ha-1 at the harvest of (100 DAS). Data showed that number of nodes per plant

were found same in both narrow and wider plant spacing at early growth and final growth

stages but at (100 DAS) narrow spacing tended to produce higher number of nodes than

wider spacing treatments and again the differences were not found significant

statistically. The interactions between nitrogen and plant spacing were found to be non

significant

Table-4.3.2 Effect of nitrogen fertilizer and plant spacing on nodes per plant
50 DAS 100 DAS 150 DAS
Nitrogen
Spacing (cm) Spacing (cm) Spacing (cm)
(Kg ha-1)
15 30 Means 15 30 Means 15 30 Means
0 21 21 21.0 26 26 26.0b 30 30 30.0
100 22 22 22.0 28 27 27.5ab 31 31 31.0
150 22 22 22.0 29 28 28.5a 32 32 32.0
Means 21.7 21.7 27.7 27.0 31.0 31.0
SEs
Nitrogen 1.04 0.62 1.85
Plant spacing 1.21 0.67 2.55
NxS 2.09 1.56 4.41
LSD (5%)
Nitrogen ns 1.73 ns
Plant spacing ns ns ns
NxS ns ns ns

Inter-nodal distance (cm)

Data presented in the Table (4.3.3) showed that there were slight differences among

different treatments of nitrogen fertilizer and spacing. Thus, each increment of nitrogen

177
fertilizer tended to produce a more inter-nodal distance through out the crop growth in all

growth stages but the differences were not significant statistically. In the spacing

treatments, the narrow spacing tended to produce more inter-nodal distance than wider

spacing through out the crop growth but the differences were not significant statistically.

It is observed that interactions between different treatments of nitrogen fertilizer and

spacing were found to be non significant.

Table-4.3.3 Effect of nitrogen fertilizer and plant spacing on Inter-nodal distance

(cm)
50 DAS 100 DAS 150 DAS
Nitrogen
Spacing (cm) Spacing (cm) Spacing (cm)
(Kg ha-1)
15 30 Means 15 30 Means 15 30 Means
0 3.05 3.00 3.03 3.23 3.15 3.19 3.50 3.47 3.49
100 3.08 3.01 3.05 3.25 3.22 3.24 3.52 3.48 3.50
150 3.14 3.14 3.14 3.28 3.25 3.27 3.56 3.50 3.53
Means 3.09 3.05 3.25 3.21 3.53 3.48
SEs
Nitrogen 0.10 0.08 0.13
Plant spacing 0.10 0.04 0.17
NxS 0.14 0.06 0.30
LSD (5% )
Nitrogen ns ns ns
Plant spacing ns ns ns
NxS ns ns ns

Square initiation (days)

Data pertaining to Square Initiation showed that there was slight difference among

different treatments of nitrogen fertilizer and spacing. Thus, each increment of nitrogen

delays the flower initiation but the differences were not significant statistically. In the

178
spacing treatments increased plant to plant spacing delay the Square initiation. However,

the narrow spacing earliar the Square initiation but the differences between the spacing

were not significant statistically.

The interactions between different treatment of nitrogen fertilizer and spacing were found

to be not significant.

Table-4.3.4 Effect of nitrogen fertilizer and plant spacing on square initiation (days)
Treatment Plant spacing (cm)
Nitrogen (kg ha-1) 15 30 Means
0 24 25 24.5
100 25 26 25.5
150 26 26 26.0
Means 25.0 25.7
SEs
Nitrogen 1.98
Plant spacing 2.87
NxS 4.97
LSD (5%)
Nitrogen ns
Plant spacing ns
NxS ns

Flower initiation (days)

A similar observation like that of squaring was also appeared for flower initiation. Data

showed that each increment of nitrogen tended to delay the flower initiation but the

differences were not significant statistically. However, wider spacing delayed flowering

179
initiation and narrow spacing earlier the flowering but the differences between the

spacing were not found significant statistically.

However, the interactions between different treatment of nitrogen fertilizer and spacing

were found to be not significant.

Table-4.3.5 Effect of nitrogen fertilizer and plant spacing on flower initiation

(days)
Treatment Plant spacing (cm)
-1
Nitrogen (kg ha ) 15 30 Means
0 44 44 44.0
100 45 46 45.5
150 46 47 46.5
Means 45.0 45.7
SEs
Nitrogen 3.09
Plant spacing 2.20
NxS 3.82
LSD (5%)
Nitrogen ns
Plant spacing ns
NxS ns

Boll split initiation (days)

Observation like that of squaring and flowering was also found for boll initiation. Results

showed that boll initiation delay with each increment of nitrogen but the differences were

not significant statistically. However, wider spacing treatments delay the boll split

initiation than narrow spacing but the differences were not significant statistically.

180
The interactions between different treatment of nitrogen fertilizer and spacing were also

found to be not significant.

Table-4.3.6 Effect of nitrogen fertilizer and plant spacing on boll split initiation
(days)
Treatment Plant spacing (cm)
Nitrogen(kg ha-1) 15 30 Means
0 80 81 80.5
100 82 82 82.0
150 82 83 82.5
Means 81.3 82.0
SEs
Nitrogen 2.20
Plant spacing 2.37
NxS 4.10
LSD (5%)
Nitrogen ns
Plant spacing ns
NxS ns

Number of bolls m-2

Data presented in the Table (4.3.7) showed that there were significant differences among

different treatments of nitrogen application and spacing. It is evident from the results that

each increment of nitrogen fertilizer produced more number of bolls but the higher

nitrogen rates (i.e. 100 and 150 kg ha-1) did not show significant effect among

181
themselves. However, significantly the highest number of bolls (142.5 m-2) was produced

with 150 kg nitrogen ha-1 rate that was followed by 100 kg nitrogen ha-1 and lowest

number of 95.5 m-2 was observed with zero nitrogen application. Results also showed

that narrow spacing (15 cm) gave significantly (P≤0.01) more number of bolls m-2 than

wider spacing (30 cm).

The interactions between nitrogen fertilizer and spacing were found to be non-significant.

Table-4.3.7 Effect of nitrogen fertilizer and plant spacing on boll m-2

Treatment Plant spacing (cm)
Nitrogen (kg ha-1) 15 30 Means
0 102.00 89.00 95.50b
100 144.00 124.00 134.00a
150 153.00 132.00 142.50a
Means 133.00a 115.00b
SEs
Nitrogen 3.56
Plant spacing 4.06
NxS 7.04
LSD (5%)
Nitrogen 9.88
Plant spacing 9.96
NxS ns

Boll weight (g)

Results pertaining to effect of nitrogen and spacing on boll weight are presented in Table

(4.3.8). Thus, nitrogen application significantly influenced the boll weight and

significantly the highest boll weight of 2.45 (g) was observed with 150 kg nitrogen ha-1

182
followed by 100 kg nitrogen ha-1 while significantly the lowest boll weight of 2.31 (g)

was produced with zero nitrogen application. Results also showed that wider spacing (30

cm) produced higher boll weight than narrow spacing (15 cm) but the differences were

not significant statistically.

Thus, the interactions between nitrogen fertilizer and spacing were also found to be non-

significant.

Table-4.3.8 Effect of nitrogen fertilizer and plant spacing on boll weight (g)
Treatment Plant spacing (cm)
Nitrogen (kg ha-1) 15 30 Means
0 2.28 2.33 2.31b
100 2.36 2.42 2.39a
150 2.41 2.48 2.45a
Means 2.35 2.41 -
SEs
Nitrogen 0.02
Plant spacing 0.03
NxS 0.05
LSD (5%)
Nitrogen 0.07
Plant spacing ns
NxS ns

Seed cotton yield (kg ha-1)

Table (4.3.9) indicated that different treatments of nitrogen fertilizer and plant spacing

influenced significantly the seed cotton yield of cotton crop. Thus, each increment of

nitrogen fertilizer increased significantly (P≤0.05 and 0.01) the seed cotton yield

however, the highest yield of 3114 kg ha-1 was produced with highest nitrogen rate (150

kg ha-1) and the lowest yield (1731 kg ha-1) was observed with zero nitrogen application.

183
Narrow spacing (15 cm) produced significantly (P≤0.05) higher yield than wider spacing

(30 cm). However, the interactions between nitrogen fertilizer and spacing treatments

were found to be non-significant

Table4. 3.9 Effect of nitrogen fertilizer and plant spacing on seed cotton yield (kg ha-1)
Treatment Plant spacing (cm)
Nitrogen (kg ha-1) 15 30 Means
0 1856.00 1606.00 1731.00c
100 3065.00 2691.00 2878.00b
150 3298.00 2930.00 3114.00a
Means 2740.00a 2409.00b -
SEs
Nitrogen 73.22
Plant spacing 104.30
NxS 180.65
LSD (5%)
Nitrogen 203.55
Plant spacing 255.53
NxS ns

Ginning out turn percentage (%)

Data pertaining to ginning out turn (Table-4.3.10) showed that there were differences

among different treatments of nitrogen fertilizer and plant spacing but the differences

were not significant statistically. However, the highest value of ginning out turn was

produced with the highest nitrogen rate (150 kg ha-1) and the lowest value was observed

with zero nitrogen application. Similarly, the highest value of ginning out turn was

observed with 30 cm spacing and lower value was produced with narrow spacing (15 cm)

and again the differences were not significant statistically. It is observed that interactions

between nitrogen fertilizer and spacing were not significant.

184
Table-4.3.10 Effect of nitrogen fertilizer and plant spacing on ginning outturn
percentage (%)
Treatment Plant-spacing (cm)
Nitrogen (kg ha-1) 15 30 Means
0 41.20 41.40 41.30
100 41.50 41.70 41.60
150 41.60 41.70 41.65
Means 41.43 41.60 -
SEs
Nitrogen 0.22
Plant spacing 0.11
NxS 0.19
LSD (5%)
Nitrogen ns
Plant spacing ns
NxS ns

Seed index (g)

Results revealed that different treatments of nitrogen fertilizer and spacing influenced the

seed index of cotton crop (Table-4.3.11). Thus, each increment of nitrogen tended to

increase the seed index and the differences were not significant statistically. However, the

highest value of seed index was achieved with 150 kg ha-1 nitrogen rate and the lowest

value was observed with zero nitrogen rates. Data showed that significantly (P≤0.05) the

highest seed index (8.59.g) was produced with wider spacing (30.cm) and the lowest seed

index of 8.52 (g) with narrow spacing of 15 cm. The interactions between nitrogen

fertilizer and spacing were found to be non significant.

185
Table-4.3.11 Effect of nitrogen fertilizer and plant spacing on seed index (g)
Treatment Plant spacing (cm)
Nitrogen (kg ha-1) 15 30 Means
0 8.43 8.53 8.48
100 8.53 8.57 8.55
150 8.60 8.67 8.64
Means 8.52b 8.59a -
SEs
Nitrogen 0.06
Plant spacing 0.02
NxS 0.04
LSD (5%)
Nitrogen ns
Plant spacing 0.06
NxS ns

Total fruiting points m-2

The Table (4.3.12) indicated that treatments of nitrogen fertilizer and spacing influenced

significantly the fruiting points of the crop. It is observed from the results that each

increment of nitrogen produced significantly (P≤0.05 and 0.01) higher number of fruiting

points through out the crop growth. The results showed that narrow spacing (15 cm)

treatments produced significantly (P≤0.01) higher number of fruiting points than wider

spacing (30 cm) at all growth stages. However, narrow spacing treatments at final harvest

(150 DAS) showed significantly (P≤0.01) higher fruiting points number than wider

spacing with each level of nitrogen fertilizer. It is also observed that nitrogen fertilizer in

each spacing treatments gave a significant increase in fruiting points with each increment

of nitrogen. Thus, the interaction between nitrogen and spacing treatments was found to

be significant at final harvest. These significant affects might be occurred because narrow

186
spacing treatments produced higher number of fruiting points with each increment of

nitrogen fertilizer.

Table 4.3.12 Effect of nitrogen fertilizer and plant spacing on total fruiting points m-2
Nitrogen 50 DAS 100 DAS 150 DAS
-1
(Kg ha ) Spacing (cm) Spacing (cm) Spacing (cm)
15 30 Means 15 30 Means 15 30 Means
0 90.0 75.0 82.5c 291.0 196.0 243.5c 388.7 293.0 240.9c
100 98.0 86.3 92.2b 377.0 278.0 327.5b 482.0 355.0 418.5b
150 102.3 90.3 96.3a 398.0 292.0 345.0a 493.0 375.0 434.0a
Means 96.8a 83.9b 355.3a 255.3b 454.6a 341.0b
SEs
Nitrogen 1.236 1.080 1.656
Plant spacing 1.819 2.325 2.180
NxS 3.151 4.028 3.776
LSD (5%)
Nitrogen 3.44 3.00 4.60
Plant spacing 4.46 5.70 5.34
NxS ns ns 9.25

Total intact fruits m-2

Results showed that there were significant differences among different treatments of

nitrogen fertilizer and spacing for intact fruits. It is clear from the results that each

increment of nitrogen fertilizer produced significantly (P≤0.01) the higher number of

intact fruits through out the crop growth. It is observed from the results that narrow

spacing (15 cm) produced significantly (P≤0.01) higher number of intact fruits than

wider spacing (30 cm). Thus, narrow spacing treatments at harvest (100 DAS) bearing

significantly (P≤0.01) the higher number of intact fruits than wider spacing with each

increment of nitrogen fertilizer. It is clear from the results that nitrogen fertilizer in each

187
spacing treatments produced a significant increase in fruiting points with each increment

of nitrogen

Table-4.3.13 Effect of nitrogen fertilizer and plant spacing on total intact fruits m-2
Nitrogen 50 DAS 100 DAS 150 DAS
-1
(Kg ha ) Spacing (cm) Spacing (cm) Spacing (cm)
15 30 Means 15 30 Means 15 30 Means
0 66.0 57.0 61.5c 121.0 89.0 105.0c 133.7 103.3 118.5c
100 73.0 65.3 69.2b 173.0 131.0 152.0b 182.3 137.0 159.7b
150 77.3 70.3 73.8a 190.3 142.0 166.2a 190.0 147.0 168.5a
Means 72.1a 64.2b 161.4a 120.7b 168.7a 129.1b
SEs
Nitrogen 1.453 0.776 1.596
Plant spacing 1.928 1.819 2.233
NxS 3.339 3.151 3.868
LSD (5%)
Nitrogen 4.04 2.16 4.44
Plant spacing 4.72 4.46 5.47
NxS ns 7.72 ns

100 DAS

200
-2

150
Intact fruits m

100

50

0
0 100 150
Nitrogen levels (kg ha -1 )

15cm 30cm

Fig.4.3.1 Interactive effect of nitrogen and plant spacing on intact fruits m-2

188
However the interaction between nitrogen fertilizer and spacing treatments were found to

be significant at (100 DAS) harvest.(Fig. 4.3.1) These significant affects might be

occurred because narrow spacing treatments bearing higher number of intact fruits with

each increment of nitrogen fertilizer.

Shedding percentage (%)

Data pertaining to shedding percentage (%) showed that there were significant

differences among different treatments of nitrogen fertilizer and spacing. It is observed

from the results that each increment of nitrogen tended to show lower shedding

percentage but the differences between the treatments were found to be non significant

statistically at early growth stage (50 DAS). At the harvest (100 DAS), each increment of

nitrogen showed significantly (P≤0.01) the lower shedding percentage. While at final

harvest (150 DAS), nitrogen fertilizer treatments (100 and 150 kg ha-1) gave the

significantly (P≤0.01) lower shedding percentage. It is clear from the results that wider

spacing (30 cm) showed decrease in shedding percentage at final harvest (150 DAS) but

the differences were not significant statistically. However, the early growth stages (50

and 100 DAS) showed a significant (P≤0.01) decrease in shedding percentage in wider

spacing (30 cm) than narrow spacing (15 cm). Thus, wider spacing treatments at harvest

(100 DAS) significantly (P≤0.05) showed lower shedding percentage than narrow

spacing with each increment of nitrogen fertilizer.

189
Table-4.3.14 Effect of nitrogen fertilizer and plant spacing on shedding percentage
(%)
50 DAS 100 DAS 150 DAS
Nitrogen
Spacing (cm) Spacing (cm) Spacing (cm)
(Kg ha-1)
15 30 Means 15 30 Means 15 30 Means
0 26.7 24.0 25.4 58.4 54.6 56.5a 65.6 64.8 65.2a
100 25.5 24.4 25.0 54.1 52.9 53.5b 62.2 61.4 61.8b
150 24.5 22.2 23.4 52.2 51.4 51.8c 61.5 60.8 61.2b
Means 25.6a 23.5b 54.9a 53.0b 63.1 62.3
SEs
Nitrogen 0.91 0.08 0.26
Plant spacing 0.79 0.26 0.42
NxS 1.37 0.44 0.73
LSD (5%)
Nitrogen ns 0.23 0.72
Plant spacing 1.94 0.63 ns
NxS ns 1.09 ns

100 DAS
Shedding percentage (%)

70

60

50

40
0 100 150
-1
Nitrogen levels (kg ha )

15cm 30cm

Fig-4.3.2 Interactive effect of nitrogen and plant spacing on shedding percentage

190
 The interactions between nitrogen fertilizer and spacing treatments were found to be

significant at harvest (100 DAS). (Fig. 4.3.2) These significant affects might be occurred

because wider spacing treatments showed lower shedding percentage with each

increment of nitrogen fertilizer.

Vegetative dry matter (g m-2)

Results revealed that different treatments of nitrogen fertilizer and spacings influenced

significantly by vegetative dry matter of cotton crop. It is clear from the data that

increment of nitrogen produced significantly (P≤0.05 and 0.01) more vegetative dry

matter through out the crop growth. On contrary, each increase in spacing decreased

significantly the vegetative dry matter.

Table 4.3.15 Effect of nitrogen fertilizer and plant spacing on vegetative dry matter (g m-2)
Nitrogen 50 DAS 100 DAS 150 DAS
(kg ha-1) Spacing (cm) Spacing (cm) Spacing (cm)
15 30 Means 15 30 Means 15 30 Means
0 77.3 62.2 69.8c 185.4 124.0 154.7c 250.6 214.9 232.8c
100 84.9 72.5 78.7b 306.1 248.4 277.3b 323.9 277.0 300.5b
150 90.0 75.1 82.6a 320.6 267.9 294.3a 339.6 280.9 310.3a
Means 84.1a 69.9b 270.7a 213.4b 304.7a 257.6b
SEs
Nitrogen 1.03 1.81 1.78
Plant spacing 1. 95 2.21 1.89
NxS 3.39 3.83 3.27
LSD (5%)
Nitrogen 2.87 5.04 4.96
Plant spacing 4.79 5.42 4.62
NxS ns ns 8.00

191
 150 DAS

400

Vegitative dry matter

350
300
250

g m -2
200
150
100
50
0
0 100 150
-1
Nitrogen levels (kg ha )

15cm 30cm

Fig-4.3.3 Interactive effect of nitrogen and plant spacing on vegetative dry

matter g m-2

Narrow spacing (15 cm) produced significantly (P≤0.01) more vegetative dry matter than

wider spacing (30 cm). Further, narrow spacing treatments at final harvest (150 DAS)

produce significantly (P≤0.01) more vegetative dry matter than wider spacing with each

increment of nitrogen fertilizer (Fig. 4.3.3).

It is clear from the results that nitrogen fertilizer in each spacing treatments produced a

significant increase in vegetative dry matter with each increment of nitrogen. However, it

is evident from the results that interaction between nitrogen fertilizer and spacing

treatment were found to be significant at final harvest. This significant affect might be

occurred because the narrow spacing treatments produced more vegetative dry matter in

each increment of nitrogen than wider spacing.

Reproductive dry matter (g m-2)

The observation like that of vegetative dry matter was also appeared for the reproductive

dry matter. Data presented in Table (4.3.16) showed that reproductive dry matter

influenced significantly by different treatments of nitrogen fertilizer and spacings.

192
Results showed that each increment of nitrogen produced significantly (P≤0.05 and 0.01)

more reproductive dry matter through out the crop growth. It is clear from the results that

each increase in spacing significantly decreases the reproductive dry matter. Narrow

spacing (15 cm) treatments at final harvest (150 DAS) produced significantly (P≤0.01)

more reproductive dry matter than wider spacing with each increment of nitrogen

fertilizer. (Fig. 4.3.4) However, nitrogen fertilizer in each spacing treatments showed a

significant increase in reproductive dry matter with each increment of nitrogen.

Table-4.3.16 Effect of nitrogen fertilizer and plant spacing on reproductive dry

matter (g m-2)
Nitrogen 50 DAS 100 DAS 150 DAS
(Kg ha-1) Spacing (cm) Spacing (cm) Spacing (cm)
15 30 Means 15 30 Means 15 30 Means
0 45.2 32.3 38.8c 243.6 150.0 196.8c 360.3 289.4 324.9c
100 54.6 44.2 49.4b 441.5 343.4 392.5b 525.5 398.4 462.0b
150 58.7 47.9 53.3a 476.1 386.0 431.1a 560.1 426.0 493.1a
Means 52.8a 41.5b 387.1a 293.1b 482.0a 371.3b
SEs
Nitrogen 1.10 1.76 1.55
Plant spacing 2.17 2.71 2.29
NxS 3.76 4.70 3.99
LSD (5%)
Nitrogen 3.04 4.88 4.30
Plant spacing 5.32 6.65 5.61
NxS ns ns 9.72

193
 150 DAS

600

Reprductive dry matter

500
400

g m-2 300
200
100
0
0 100 150
-1
Nitrogen levels (kg ha )

15cm 30cm

Fig-4.3.4 Interactive effect of nitrogen and plant spacing on reproductive dry

matter

It is obvious from the results that interactions between nitrogen fertilizer and spacing

were found to be significant at final harvest (150 DAS). These significant affects might

be occurred because the spacing behavior resulted in significant (P≤0.01) higher

reproductive dry matter of narrow spacing (15 cm).

Reproductive-vegetative ratio

Results indicated that there were significant differences among different treatments of

nitrogen fertilizer and spacings. Results also showed that each increment of nitrogen

produced significantly (P≤0.01) the higher value ratio at the final growth stages (100 and

150 DAS). While, at the early growth stage (50 DAS), the nitrogen doses (100 and 150

kg ha-1) produced significantly (P≤0.01) higher ratio value than zero kg nitrogen ha-1 but

the difference between both treatments 100 and 150 kg ha-1were found to be non

significant. It is clear from the results that each increase in spacing decreases significantly

the reproductive-vegetative ratio value. However, the narrow spacing treatments gave

194
significant (P≤0.05 and 0.01) higher reproductive-vegetative ratio value through out the

crop growth than wider spacing with each increment of nitrogen fertilizer.

It is evident from the results that interaction between the nitrogen fertilizer and spacing

were found to be significant at final harvest growth stages. (Fig. 4.3.5-6) These

significant might be occurred because narrow spacing treatments showed significantly

higher ratio value in each increment of nitrogen than wider spacing.

Table 4.3.17 Effect of nitrogen fertilizer and plant spacing on reproductive-

vegetative ratio
50 DAS 100 DAS 150 DAS
Nitrogen
Spacing (cm) Spacing (cm) Spacing (cm)
(Kg ha-1)
15 30 Means 15 30 Means 15 30 Means
0 0.58 0.52 0.55b 1.31 1.21 1.26c 1.44 1.35 1.40c
100 0.64 0.61 0.63a 1.44 1.38 1.41b 1.62 1.44 1.53b
150 0.65 0.64 0.65a 1.49 1.44 1.47a 1.65 1.52 1.59a
Means 0.62a 0.59b 1.41a 1.34b 1.57a 1.44b
SEs
Nitrogen 0.01 0.01 0.01
Plant spacing 0.01 0.00 0.01
NxS 0.02 0.01 0.01
LSD (5%)
Nitrogen 0.03 0.02 0.01
Plant spacing 0.03 0.01 0.01
NxS ns 0.01 0.02

195
 100 DAS

Reproductive- vegitative ratio

1.5

0.5
0 100 150
Nitrogen levels (kg ha-1)

15cm 30cm

Fig 4.3.5 Interactive effect of nitrogen and plant spacing on reproductive-

vegetative ratio at 100 DAS

150 DAS

2
Reproductive vegitative ratio

1.5

0.5
0 100 150
-1
Nitrogen levels (kg ha )

15cm 30cm

Fig-4.3.6 Interactive effect of nitrogen and plant spacing on reproductive-

vegetative ratio at 150DAS

196
Total plant dry matter (g m-2)

Total plant dry matter of cotton crop was influenced significantly by different treatments

of nitrogen fertilizer and spacings. It is clear from the results that each increment of

nitrogen fertilizer increased significantly (P≤0.01) the total plant dry matter at all growth

stages. Results showed that increase in spacing decrease significantly (P≤0.01) the total

dry matter of plant at all growth stages. Thus, narrow spacing at final harvest (150 DAS)

increased significantly (P≤0.01) the total plant dry matter than wider spacing with each

increment of nitrogen fertilizer (Fig. 4.3.7).

Table-4.3.18 Effect of nitrogen fertilizer and plant spacing on plant dry matter
(gm-2)
50 DAS 100 DAS 150 DAS
Nitrogen
Spacing (cm) Spacing (cm) Spacing (cm)
(Kg ha-1)
15 30 Means 15 30 Means 15 30 Means
0 122.5 94.5 108.5c 429.0 274.0 351.5c 610.9 504.3 557.6c
100 139.5 116.7 128.1b 747.6 591.8 669.7b 849.4 675.4 762.4b
150 148.7 125.0 136.9a 796.7 653.9 725.3a 899.7 706.9 803.3a
Means 136.9a 112.1b 657.8a 506.6b 786.7a 628.9b

SEs
Nitrogen 1.74 3.35 3.33
Plant spacing 4.10 4.88 4.08
NxS 7.10 8.45 7.06
LSD (5%)
Nitrogen 4.83 9.31 9.25
Plant spacing 10.04 11.95 9.99
NxS ns ns 17.30

197
 150 DAS

1000

-2
Plant dry matter g m
800

600

400

200

0
0 100 150
Nitrogen levels (kg ha-1)

15cm 30cm

Fig-4.3.7 Interactive effect of nitrogen and plant spacing on plant dry matter g m-2

The interaction between nitrogen fertilizer and spacing were found to be significant at

final harvest. These significant affects might be occurred because at maturity, the total

plant dry matter is more and the narrow spacings showed significantly more total plant

dry matter than wider spacings.

Staple length (mm)

Results showed that a similar observation like that of ginning out turn percentage was

occurred here (Table-4.3.19). Thus each increment of nitrogen tended to produce higher

value of staple length and the differences were not significant statistically. Similarly,

higher value of staple length was produced with wider spacing and lower value of staple

length was obtained with narrow spacing and again the differences were not significant

statistically. However, the interactions between nitrogen fertilizer and spacing treatments

were also found to be non- significant.

198
Table-4.3.19 Effect of nitrogen fertilizer and plant spacing on staple length (mm)
Treatment Plant spacing (cm)
Nitrogen (kg ha-1) 15 30 Means
0 27.30 27.30 27.30
100 27.40 27.30 27.35
150 27.30 27.60 27.45
Means 27.33 27.40 -
SEs
Nitrogen 0.13
Plant spacing 0.11
NxS 0.19
LSD (5%)
Nitrogen ns
Plant spacing ns
NxS ns

Micronaire value (ug inch-1)

Data pertaining to micronaire value showed that the highest rate of nitrogen slightly

increased the micronaire value but the differences were not significant statistically.

Similarly spacing treatments did not affect significantly the micronaire values of cotton

crop. Again the interactions between nitrogen fertilizer and spacing treatments were also

found to be non-significant.

199
Table-4.3.20 Effect of nitrogen fertilizer and plant spacing on micronaire value
(ug inch-1)
Treatment Plant spacing (cm)
Nitrogen (kg ha-1) 15 30 Means
0 4.43 4.33 4.38
100 4.43 4.33 4.38
150 4.60 4.53 4.57
Means 4.49 4.40 -
SEs
Nitrogen 0.07
Plant spacing 0.08
NxS 0.14
LSD (5%)
Nitrogen ns
Plant spacing ns
NxS ns

Uniformity index (%age)

Results showed that uniformity ratio was influenced significantly by the different

treatments of nitrogen fertilizer and plant spacing (Table-4.3.21) However, each

increment of nitrogen fertilizer to produce higher value of uniformity ratio and

significantly the lowest value was observed with zero nitrogen rate and the highest value

was produced with 150 kg nitrogen ha-1 rate. It is clear from the results that narrow

spacing produced significantly (P≤0.05) the higher value of uniformity ratio. The

interactions between nitrogen fertilizer and spacing were not significant.

200
Table-4.3.21 Effect of nitrogen fertilizer and plant spacing on uniformity index
(%age)
Treatment Plant spacing (cm)
Nitrogen (kg ha-1) 15 30 Means
0 80.13 79.60 79.87b
100 80.20 80.10 80.15ab
150 81.10 80.20 80.65a
Means 80.48a 79.97b -
SEs
Nitrogen 0.21
Plant spacing 0.16
NxS 0.27
LSD (5%)
Nitrogen 0.58
Plant spacing 0.38
NxS ns

Fiber strength (tppsi)

Results showed that fiber strength was influenced significantly by the treatments of

nitrogen fertilizer while the spacing treatments did not affect the fiber strength (Table

4.3.22). It is observed from the data that higher nitrogen rates (100 and 150 kg ha-1)

produced significantly (P≤0.01) higher fiber strength than zero nitrogen application but

these higher nitrogen rates were not significant among themselves.

It is evident from the results that the interactions between nitrogen fertilizer and spacing

were found to be non-significant.

201
Table-4.3.22 Effect of nitrogen fertilizer and plant spacing on fiber strength (tppsi)
Treatment Plant spacing (cm)
Nitrogen (kg ha-1) 15 30 Means
0 93.60 92.90 93.30b
100 94.20 95.00 94.60a
150 95.10 94.70 94.90a
Means 94.30 94.20
SEs
Nitrogen 0.26
Plant spacing 0.24
NxS 0.42
LSD (5%)
Nitrogen 0.71
Plant spacing ns
NxS ns

Fiber elongation (%age)

Results showed that fiber elongation increased with each increment of nitrogen but the

differences were not significant statistically. However, wider spacing treatments

increased significantly (P≤0.05) the fiber elongation than narrow spacing. The

interactions between nitrogen fertilizer and plant spacing were also found to be non

significant.

202
Table-4.3.23 Effect of nitrogen fertilizer and plant spacing on fiber elongation
(%age)
Treatment Plant spacing (cm)
Nitrogen (kg ha-1) 15 30 Means
0 5.90 6.20 6.05c
100 6.60 6.50 6.55b
150 6.30 6.90 6.60a
Means 6.27b 6.53a -
SEs
Nitrogen 0.18
Plant spacing 0.10
NxS 0.18
LSD (5%)
Nitrogen ns
Plant spacing 0.25
NxS ns

Maturity ratio

Data presented in the (Table-4.3.24) indicated that fiber maturity was influenced

significantly by the nitrogen fertilizer treatments. It is clear from the data that each

increment of nitrogen fertilizer produced significantly the higher value of fiber maturity

(P≤0.05 and 0.01). It is observed that spacing treatments did not affect the maturity ratio

value however, wider spacing produced higher value of fiber maturity but the differences

were not significant statistically.

Thus, the interactions between nitrogen fertilizer and spacing treatments were also found

to be non-significant

203
Table-4.3.24.Effect of nitrogen fertilizer and plant spacing on maturity ratio
Treatment Plant spacing (cm)
Nitrogen (kg ha-1) 15 30 Means
0 1.06 1.07 1.07c
100 1.09 1.08 1.09b
150 1.09 1.10 1.10a
Means 1.08 1.08 -
SEs
Nitrogen 0.00
Plant spacing 0.01
NxS 0.01
LSD (5%)
Nitrogen 0.01
Plant spacing ns
NxS ns

Brightness (Rd)

Results showed that there were significant differences among different treatments of

nitrogen fertilizer for brightness of the fiber (Table-4.3.25). Thus, each increment of

nitrogen fertilizer tended to produce higher value of brightness but significant differences

were observed between higher nitrogen rates (i.e. 100 and 150 kg ha-1) and zero nitrogen

application treatments. Results also showed that narrow spacing treatments produce

higher value of brightness but the differences were not significant statistically. The

interactions of nitrogen fertilizer and spacing were not found to be significant.

204
Table-4.3.25 Effect of nitrogen fertilizer and plant spacing on brightness (Rd)
Treatment Plant spacing (cm)
Nitrogen (kg ha-1) 15 30 Means
0 71.10 71.60 71.35b
100 72.90 72.30 72.60a
150 72.90 72.60 72.75a
Means 72.30 72.17 -
SEs
Nitrogen 0.34
Plant spacing 0.36
NxS 0.62
LSD (5%)
Nitrogen 0.96
Plant spacing ns
NxS ns

Yellowness (+b)

Data pertaining to yellowness (Table-4.3.26) showed that there was a slight difference

among different treatments of nitrogen fertilizer and spacing. Thus, each increment of

nitrogen tended to produce higher value of yellowness but the differences were not

significant statistically. In contrast to brightness, the narrower spacing treatments produce

lower value of yellowness than wider spacing and the again the differences were not

significant statistically. It is observed that interactions between different treatments of

nitrogen fertilizer and spacing were found to be non-significant.

205
Table-4.3.26 Effect of nitrogen fertilizer and plant spacing on yellowness (+b)
Treatment Plant spacing (cm)
Nitrogen (kg ha-1) 15 30 Means
0 7.10 7.30 7.20
100 7.30 7.30 7.30
150 7.20 7.50 7.35
Means 7.20 7.37 -
SEs
Nitrogen 0.13
Plant spacing 0.09
NxS 0.16
LSD (5%)
Nitrogen ns
Plant spacing ns
NxS ns

Crop growth rate (g m-2 day-1)

Crop growth rate was influenced significantly by different treatments of nitrogen and

spacings (Table-4.3.27). It is clear from the results that each increment of nitrogen

fertilizer s increased significantly (P≤0.05) the growth rate during the early growth stages

(i.e. 50 and 100 DAS) while; at the final harvest (150 DAS) nitrogen decreased

significantly the growth rate. Results also showed that narrow spacing increased

significantly (P≤0.0.5) the crop growth rate throughout the crop growth. The interactions

between nitrogen fertilizer and spacing during early growth stages were not significant

but at the final harvest were found to be significant. These significant affects at maturity

might because that the treatments where nitrogen was applied either narrow or wider

spacing showed significant decrease in growth rate than zero nitrogen application

treatment (Fig. 4.3.8).

206
Table-4.3.27 Effect of nitrogen fertilizer and plant spacing on crop growth rate
(gm-2 day-1)
50 DAS 100 DAS 150 DAS
Nitrogen
Spacing (cm) Spacing (cm) Spacing (cm)
(Kg ha-1)
15 30 Means 15 30 Means 15 30 Means
0 2.45 1.89 2.17c 6.13 3.59 4.86c 3.64 3.61 3.63a
100 2.79 2.33 2.56b 12.16 9.50 10.83b 2.04 1.67 1.86b
150 2.97 2.50 2.74a 12.97 10.58 11.78a 2.06 1.06 1.56c
Means 2.74a 2.24b - 10.42a 7.89b - 2.58 2.11 -

SEs
Nitrogen 0.01 0.03 0.03
Plant spacing 0.02 0.04 0.02
NxS 0.04 0.07 0.03
LSD (5% )
Nitrogen 0.04 0.08 0.08
Plant spacing 0.06 0.09 0.05
NxS ns ns 0.08

4.00
3.50
Crop Growth Rate

3.00
2.50
2.00
1.50
1.00
0.50
0.00
0 100 150
-1
Nitrogen Level (kg ha )

15 cm 30 cm

Fig. 4.3.8 Interactive effect of nitrogen levels and plant spacing on crop growth
rate (gm-2 day-1) at 150 DAS

207
Relative growth rate (g g-1 day-1)
Relative growth rate showed a similar observation like that of growth rate and influenced

significantly by different treatments of nitrogen and spacings (Table-4.3.28).

Table 4.3.28 Effect of nitrogen fertilizer and plant spacing on relative crop growth
rate (g g-1 day-1)
50 DAS 100 DAS 150 DAS
Nitrogen
Spacing (cm) Spacing (cm) Spacing (cm)
(Kg ha-1)
15 30 Means 15 30 Means 15 30 Means
0 *4.18 3.95 4.07b 1.09 0.93 1.01b 0.31 0.53 0.42a
100 4.29 4.13 4.21a 1.46 1.41 1.44a 0.11 0.12 0.12b
150 4.34 4.09 4.27a 1.46 1.44 1.45a 0.11 0.07 0.09c
Means 4.27a 4.06b - 1.34 1.26 - 0.18b 0.24a -
SEs
Nitrogen 0.03 0.03 0.01
Plant spacing 0.05 0.04 0.02
NxS 0.08 0.06 0.04
LSD (5% )
Nitrogen 0.09 0.09 0.02
Plant spacing 0.11 ns 0.05
NxS ns ns 0.09
1.00
Relative Growth Rate

0.80

0.60

0.40

0.20

0.00

0 100 150
Nitrogen Level (kg ha-1)

15 cm 30 cm

Fig. 4.3.9 Interactive effect of nitrogen levels and plant spacing on relative
growth rate (g g-1 day-1) at 150 DAS

208
Results showed that relative growth rate was increased significantly with each increment

of nitrogen (P≤0.05) during the early growth stages while, at the final harvest, relative

growth rate was decreased significantly with each increase in nitrogen fertilizer and the

lowest growth rate value was produced with the highest nitrogen rate. It is observed that

narrow spacing gave the higher values during early stages but significant differences

were occurred on 50 DAS however, at the final harvest narrow spacing treatments gave

significantly (P≤0.05) lower value of relative growth rate. Again it is evident from the

results that interactions between the nitrogen and spacing treatment during early growth

stages were not significant but at the final harvest were found to be significant. These

significant affects at maturity might because that the treatments where nitrogen was

applied either narrow or wider spacing showed significant decrease in growth rate than

zero nitrogen application treatment (Fig. 4.3.10).

4.3.3 DISCUSSION

The efficient use of fertilizers is an important goal in maximizing yield of a crop in a way

that has a minimal impact on the environment. During the recent years, researchers make

critical analysis of agricultural systems using high inputs such as nitrogen fertilizer

(Kirchmann and Thorvaldsson, 2000).However, nitrogen is an essential nutrient for

cotton that affects plant growth, fruiting and final yield. It plays a major role in defining

the expression of a wide range of plant variables including plant size, fruiting intensity,

boll retention, and size and total number of boll per plant (Geric, et al., 1998). Judicial

use of nitrogen is considered a vital character in growth and yield that determined by

many variables including weather, soil type, residual fertility, type of cultivars and plant

spacing etc. In the experiment III, the seed cotton yield increased with nitrogen

209
fertilization. Thus, each increment of nitrogen fertilizer in both the spacings produced

significantly higher seed cotton yield. However, the narrow spacing 15cm treatments

increased significantly yield. A number of scientists have reported that nitrogen increased

the number of bolls plant-1, boll weight and seed cotton yield (Marsh, et al., 2000; Parsad,

2000; Giri, et al., 1994; Brar, et al ., 1993; Elayan, 1992., Patel, et al .,1992). It is

obvious from the results that nitrogen is an important element for plant growth as each

incremental dose of nitrogen produced the taller plants in both the spacings (15 and 30

cm). However, the highest nitrogen rate 150 kgha-1 produced significantly the tallest

plants than zero nitrogen application. Results are in conformity to other scientists who

reported that nitrogen fertilization increased the plant height (Brar, et al., 1993;

Abuldahab and Hassanin , 1991).

It is widely recognized that nitrogen supply exerts a marked influence on vegetative and

reproductive growth and there is tendency of some producers to attempt to increase

maximum yield potentials by applying higher than recommended nitrogen rates reported

by (Boquet and Breitenbeck, 2000). It is clear from our study that growth and yield

components, number of intact fruits, bolls plant-1, boll weight, vegetative dry matter and

reproductive dry matter at harvest time showed significant increases with the application

of nitrogen at the highest rate of 150 kg ha-1. Whereas, the treatments with zero nitrogen

application showed the highest fruit shedding percentage which resulted in the lowest

seed cotton production.

Plant population is one of the most important factors to increase yield per unit area basis.

Plant density exhibits significant effects on seed cotton yield and its components (El-

Tabbakh, 2001). Establishment of an acceptable population of cotton seedlings is

paramount for obtaining high yields (Siebert et al., 2006). The definition of an acceptable

plant population however, varies by location, environment, cultivars and growth

210
preference. In the experiment III, plants were evaluated at two different spacings (i.e. 15

and 30 cm).The present study revealed that both the spacings with each increment of

nitrogen produced the highest seed cotton yield. However, narrow spacing (15 cm)

significantly produced higher seed cotton yield than the wider spacing. Narrow row

spacing increases total seasonal light interception which can potentially increase seed

cotton yield. Similar results were also reported by Steglich, et al., 2000; Heitholt, et al.,

1992 .A number of researchers reported that yield increases due to narrow rows were

associated with improved boll retention (Palomo, et al., 2000; Ramana et al., 2000;

Shekar, et al., 1999; Devi, et al., 1995; Heitholt,1995;Gadagi, et al., 1990).

It is evident from the results that narrow spacing increased significantly the plant height,

nodes per plant, inter-nodal distance, intact fruits, boll number and reproductive dry

matter that ultimately added to the seed cotton yield. The numbers of plants were more in

narrow row spacing producing more number of fruits per unit area which contributed in

the form of increased seed cotton yield. Boquet, et al., 1998; Gunnaway, et al., 1995

reported an increase in number of bolls m-2 with the increase in plant density. Although in

wider spacing (30 cm) higher boll weight and seed index were produced but lower

number of bolls per unit area undermined the positive effects of boll weight and seed

index resulting in considerably lower seed cotton yield under wider spacing. Results

reported by Staut and Lamas, 1999 also revealed that boll weight increased with spacing

and decreased with density.

211
4.4 Experiment–IV

Title-Plant structure and seed cotton yield of cultivars as

influenced by nitrogen fertilizer
An experiment was conducted at the Central Cotton Research Institute, Multan, Pakistan

during the cropping season 2007 on a silt loam soil having pH (8.04), EC (2.66 dSm-1)

and organic matter (0.85%). The objective of this study was to determine the response of

cotton cultivars to various levels of nitrogen application.

Experimental Design

The experiment was replicated thrice and laid out in a randomized complete block design

with split plot arrangements with two factors.

Treatments

Cultivars

C1 CIM-473
C2 CIM-496
Nitrogen levels

N1 0
N2 100
N3 150
N4 200

4.4.1 Materials and Methods

The experiment was undertaken to study the response of cotton cultivars to various levels

of nitrogen application. Cotton cultivars CIM-473 and CIM-496 were planted on May 10

at 15 cm plant to plant distance with four levels of nitrogen fertilizer i.e.0, 100,150 and

212
200 kg ha-1. The planting was done manually on bed furrows by dibbling method.

Nitrogen levels were kept in main plots and cultivars in the sub plots. Nitrogen levels (0,

100, 150 and 200 kg ha-1) were applied in three split doses on June 01, July 05, August

15. Cultural practices and plant protection measures were adopted as per requirement of

the crop. Analytical results of the soil samples collected at pre planting and after the

harvest of crop are given in Table-6.

Table-6 Chemical analysis of the experimental site (2007)

Before sowing After harvesting
Characteristics Depth (cm) Depth (cm)
0-15 15-30 0-15 15-30
-1
EC dSm 2.61 2.70 2.58 2.69
Soil pH (1:1) 8.00 8.08 8.02 8.05
Organic Matter (%) 0.86 0.83 0.87 0.84
-1
NO3-N (mg kg ) 5.58 4.52 5.69 4.64
NaHO3-P (mg kg ) -1
13.5 11.6 12.4 11.6
-1
NH4OAC–K (mg kg ) 116.0 112.0 111.0 104.0

4.4. 2 Results

Plant height (cm)

The results showed that there were significant differences among different treatments of

cultivars and nitrogen application (Table-4.4.1) on plant height. It is clear from the results

that CIM-496 produced significantly (P≤0.01) the taller plants than CIM-473. It is

observed from the results that each increment of nitrogen produced significantly (P≤0.01)

taller plants up till 150 kg nitrogen ha-1 .The highest rate of nitrogen 200 kg ha-1 tended to

produce taller plants than 150 kg nitrogen ha-1 but the differences were not significant

statistically.

213
The interactions between different treatments of cultivars and nitrogen were found to be

non significant statistically

Nodes per plant

Data presented in the (Table-4.4.1) showed that number of nodes of cotton cultivars

influenced by nitrogen application. Results showed that CIM-496 tended to produce more

number of nodes than CIM-473 but the differences were not significant statistically. It is

evident from the results that each increment of nitrogen tended to produce higher number

of nodes.

Table-4.4.1 Plant height (cm) and nodes per plant of cultivars as affected by
nitrogen fertilizer
Nitrogen Plant height (cm) Nodes per plant
(kg ha-1) CIM-496 CIM-473 Means CIM-496 CIM-473 Means
0 96.00 89.83 92.92c 33.00 31.00 32.00b
100 108.00 97.00 102.50b 35.00 33.33 34.17ab
150 114.00 103.00 108.50a 36.00 34.00 35.00a
200 115.83 105.00 110.42a 36.00 35.00 35.50a
Means 108.46a 98.71b - 35.00 33.33
SEs
Nitrogen 1.07 0.94
Cultivars 1.43 1.43
NxC 2.85 2.86
LSD (5%)
Nitrogen 2.62 2.29
Cultivars 3.29 ns
NxC ns ns

Nitrogen-N Cultivar-C

However, the higher nitrogen doses (150 and 200 kg nitrogen ha-1) produced significantly

(P≤0.05) higher number of nodes than zero nitrogen application. The nitrogen application

214
100 kg tended to produce higher number of nodes but the differences were non

significant statistically.

The interactions between cultivars and nitrogen were found to be non significant.

Inter-nodal distance (cm)

Results showed that inter-nodal distance was not influenced by different treatments of

cultivars and nitrogen application. Cultivar CIM-496 tended to increase inter-nodal

distance than CIM-473 but the differences were non significant statistically. It is clear

from the results that each increment of nitrogen tended to produce more inter-nodal

distance but again the differences between the treatments were found to be non

significant.

The interaction between the cultivars and nitrogen were found to be non significant

Number of bolls m-2

Results relating to number of bolls m-2 indicated that cultivars and nitrogen application

significantly influenced the number of bolls m-2 of cotton crop (Table-4.4.2). However,

cultivar CIM-496 produced significantly (P≤0.01) higher number of bolls m-2 than

cultivar CIM-473. It is obvious from the results that nitrogen fertilizer application

influenced significantly the number of bolls m-2 and further, each increment of nitrogen

fertilizer increased significantly (P≤0.01) the boll number up to 150 kg nitrogen ha-1. The

treatment of nitrogen 200 kg ha-1 tended to increase the number of bolls than 150 kg N

ha-1 but the differences were non significant statistically. However, the higher boll

number was produced with highest nitrogen doses (150 and 200 kg ha-1) and the lowest

number of bolls was observed with zero nitrogen treatment in both cultivars.

Other interaction of cultivars and nitrogen application were found to be non- significant.

215
Table-4.4.2 Inter-nodal distance (cm) and number of bolls m-2 of cultivars as
affected by nitrogen fertilizer
Nitrogen Inter-nodal distance (cm) Number of bolls m-2
(kg ha-1) CIM-496 CIM-473 Means CIM-496 CIM-473 Means
0 2.91 2.90 2.91 102.0 95.0 98.5c
100 3.09 2.94 3.02 140.0 132.0 136.0b
150 3.17 3.00 3.09 149.0 142.0 145.5a
200 3.22 3.00 3.11 151.0 142.0 146.5a
Means 3.10 2.96 135.5a 127.8b
SEs
Nitrogen 0.07 1.59
Cultivars 0.09 1.91
NxC 0.18 3.82
LSD (5%)
Nitrogen ns 3.91
Cultivars ns 4.41
NxC ns ns

Boll weight (g)

The results showed that there were significant differences among different treatments of

cultivars and nitrogen application (Table-4.4) on boll weight. Cultivar CIM-496 gave

significantly (P≤0.05) higher boll weight than CIM-473. It is observed from the results

that each increment of nitrogen fertilizer produced significantly (P≤0.05 and 0.01) higher

boll weight up to 150 kg nitrogen ha-1. The higher rates of nitrogen application (150 and

200 kg ha-1) produced significantly (P≤0.01 and 0.05) higher boll weight than lower rates

of nitrogen application (0 and100 kg nitrogen ha-1). However, the higher rate of nitrogen

application 200 kg ha-1 increased the weight than150 kg nitrogen ha-1 but it is non

significant statistically. It is observed from the data that interactions of cultivars and

nitrogen fertilizer were found to be non significant.

216
Seed cotton yield (kg ha-1)

Seed cotton yield of cotton cultivars influenced significantly by the treatments of nitrogen

application (Table-4.4.3). Results showed that cultivar CIM-496 produced significantly

(P≤0.01) more seed cotton yield than cultivar CIM-473. It is evident from the results that

each increment of nitrogen application produced significantly more seed cotton yield up

till 150 kg nitrogen ha-1 in both the cultivars. The nitrogen application 200 kg ha-1 tended

to produce more seed cotton yield than 150 kg N ha-1 but the differences between them

were found to be non significant.. Thus, the highest yield was produced with the highest

nitrogen rate (200 kg ha-1) and the lowest seed cotton yield was observed with zero

nitrogen treatments in both cultivars. It is evident from the results that interactions

between cultivars and nitrogen application were found to be non significant.

Table-4.4.3 Boll weight (g) and seed cotton yield (kg ha-1) of cultivars as affected by
nitrogen fertilizer
Nitrogen Boll weight (g) Seed cotton yield (kg ha-1)
(kg ha-1) CIM-496 CIM-473 Means CIM-496 CIM-473 Means
0 2.40 2.36 2.38c 2142.0 1916.0 2029.0c
100 2.48 2.44 2.46b 3050.0 2773.0 2911.5b
150 2.53 2.49 2.51a 3490.0 3179.0 3334.5a
200 2.55 2.50 2.53a 3512.0 3195.0 3353.5a
Means 2.49a 2.45b 3048.5a 2765.8b
SEs
Nitrogen 0.02 43.18
Cultivars 0.02 60.32
NxC 0.03 120.65
LSD (5%)
Nitrogen 0.05 105.78
Cultivars 0.04 139.35
NxC ns ns

217
4.4.3 DISCUSSION

Nitrogen is a constituent of all proteins and enzymes, several metabolic intermediates in

synthesis, energy transfer and DNA. High yield goals in cotton crop are not achieved

through promising cultivar selection but also giving serious consideration to determine

appropriate dose of nitrogen. Nitrogen plays a dominant role in growth processes.

Nitrogen fertilizer requirement depends on many factors including yield targets, nitrogen

concentration, soil type, numerous environmental factors and cultivating higher yield

responsive varieties. Nitrogen is one of the most important nutrient needed by plants in

large quantities. Proper nitrogen fertilization in upland cotton can often be viewed as

more of an art form rather than a science. Application rates decisions often must factor in

such variables as soil texture and realistic yield goals. The trend of heavy and unbalanced

fertilizer has resulted in increased pesticide sprays that in turn enhance the cost of input

manifold. People involved in crop production are always advocating that incorrect use of

any one of the nutrients essential to plant growth will result in serious reduction in the

yield and quality of crop (Chaudhry and Sarwar 1999). In the Experiment IV each

incremental dose of nitrogen fertilizer in both cultivars up to 150 kg ha-1 significantly

increased the growth yield, and yield components. Similarly each increment of nitrogen

fertilizer up to 150 kg ha-1 significantly increased the number of bolls, boll weight which

ultimately contributed increase the seed cotton yield. There was no significant difference

between 150 and 200 kg ha-1. Some other scientists reported that average weight of seed

cotton per boll increased with increasing nitrogen fertilizer rate, or higher seed cotton

yield was obtained with higher level of nitrogen (Ansari, and Mahey 2003; Ali and

Sayed., 2001; Parsad, et al., 2000; Assy and Malak, 1997; Yadar and Rajput, 1996; Brar,

et al., 1993; Elayan, 1992) It is also observed that nitrogen produced a better impact on

218
plant height along with stem nodes and inter-nodal distance as each increment of nitrogen

produced taller plants in both cultivars Thus significantly the tallest plants were found

with the nitrogen level of 150 kg ha-1. The differences between 150 and 200 kg ha-1 were

non significant on overall average basis. Similar studies by other researchers also

revealed that increasing nitrogen levels caused increase in plant height (Ali and Sayed;

2001; Boquet and Breitenbeck 2000; Debaby, et al., 1995; Brar, et al., 1993).

Cotton is currently the leading fiber crop worldwide and is grown commercially in the

temperate and tropical region of more than fifty countries (Smith, 1999).Despite the fact

that cotton breeders all over the world have been making continuous efforts for the

improvement of yield and quality of cotton crop, yet these efforts have not proved to be

good enough to achieve the yield average to a level of other cotton growing countries of

the world. Apart from other exigencies, one of the most conspicuous reasons for low

productivity could be inferior genotype of our cotton plants. The break through in higher

yield and cotton production may be achieved by the exploitation of hybrid vigour .Cotton

cultivars differ in growth characteristics, such as height, fruit development, maturity,

earliness, yield potential and many fiber properties. The potential of applying basic

physiological research to develop new cotton cultivars is an application worthy of the

efforts Thus in current study cultivar CIM-496 produced taller plants with each increment

of nitrogen along with increased number of nodes, inter-nodal distance, and number of

bolls & boll weight which ultimately produced higher seed cotton yield. Other scientists

reported that cotton cultivars showed significant response to different nitrogen levels (Mc

Connel et al, 2000; Pazzetti, et al., 1999) Such as the investigation that genotypic

variability was recorded for bolls per plant, boll weight and seed cotton yield were

reported.

219
 GENERAL DISCUSSION

Cotton being a perennial plant has indeterminate growth behaviour. The fruiting and

vegetative growth phases overlap temporarily and therefore, it is difficult to distinguish

the duration of these phases. Thus, considerations in the physiological development of

cotton are given to the time of beginning of the reproductive growth and the date of

completion of the vegetative growth (Sekloka et al., 2007). Generally, the reproductive

growth starts with the appearance of first flower and it is the most common indicator used

to characterize the onset of the fruiting phase. Nitrogen fertilizer significantly accelerated

the crop growth rate during the early growth stages which slowed down at the final

harvest time. It is also apparent from the results that the growth rate increased with each

increment of nitrogen uptil 100 DAS and later on it decreased with each increase in

nitrogen (Fig. 1).

Selection of a cotton cultivars that differs in growth characteristics, yield potential and

fiber quality, for cropping system in a region especially with narrow plant spacing

technique, is of prime importance to realize optimum yield. Among the cultivars

evaluated under the study, CIM-473 showed a better performance with more intact fruits,

less shedding percentage and more boll numbers that resulted higher seed cotton yield

and also more lint percentage with higher brightness than CIM-482 through out the study.

The comparison of cultivar CIM-496 and CIM-473 in another study revealed that cultivar

CIM-496 responded better to the agro-climatic conditions of the region by producing

taller plants with more number of nodes that resulted in higher vegetative dry matter

yield, more boll number and heavier bolls than CIM-473 that resulted into higher seed

cotton production.

220
 12

10

Crop Growth Rate

8

0
0 50 100 150
-1
Nitrogen (Kg ha )

50 DAS 100 DAS 150 DAS

Fig. 1 Crop Growth Rate as affected by different nitrogen levels.

3600
3200
2800
Yield (Kg ha )
-1

2400
2000
1600
1200
800
400
0
0 50 100 150 200

Nitrogen Levels (Kg ha-1)

Fig. 2 Seed cotton yield as affected by different Nitrogen levels

3600
3200
2800
Yield (Kg ha )
-1

2400
2000
1600
1200
800
400
0
15cm 30cm 45cm

Plant Spacing

Fig. 3 Seed cotton yield as affected by different Plant spacing

221
These results are in line with the findings of other scientists (Bange et al., 2008; Bange et

al., 2004; Hassan et al., 2003; Oad et al., 2002) who studied the characteristics of cotton

cultivars in different parts of Australia and Pakistan and reported that cultivars differ in

height, fruit development, drought tolerance, maturity, earliness yield potential and fiber

quality.

Agronomic consideration for growers is to ensure optimum yield and quality of a crop.

Cotton is responsive to its surrounding environments, thus, an importance must be given

to sowing time for optimum yield potential of a cultivar. Crop sown earlier produced

taller plants, more node number, more intact fruits, more boll number, less shedding

percentage that resulted in producing more seed cotton yield. Moreover, the early sown

crop contributed towards higher plant dry matter and lint with more brightness. It is

evident from the results that crop sown earlier on May 10 produced 18 and 73 percent

more seed cotton yield than crops sown later on June 01 and 20 respectively. Thus, crop

sown earlier got established earlier and was able to utilize the available nutrients and

mobilized the photosynthates in a better way that ultimately transformed into higher

yield. Previous studies that support our results have also produced similar findings like

increase in boll number that led towards increase in yield (Arshad, et al., 2007; Ali et al.,

2005; Davidonis et al., 2004; Akhter et al., 2002; Gormus and Yucel, 2002 and Bauer et

al., 1998). Almost similar findings revealed that higher boll number in crop sown earlier

than normal planting, also resulted in 10 % more yield (Pettigre., 2002).

Plant stand and geometry influence the soil moisture extraction, light interception,

humidity and wind movement and these factors in turn influence the plant height,

development, fruit location and size and crop maturity (Heitholt et al., 1992). In the

present study, plants were evaluated at different spacing of 15, 30 and 45 cm. Narrow

222
plant spacing of 15 cm hastened earliness, produced taller plants, more node number,

higher number of fruiting points, more boll number and higher seed cotton yield.

Moreover, reproductive dry matter and reproductive vegetative ratio was also enhanced

with narrow spacing. Again it is observed that narrow spacing of 15 cm produced of 19

and 67 percent more seed cotton yield than wider spacing of 30 and 45 cm respectively

(Fig. 2). Crop potential is dependent on optimum plant stand that hastens the utilization

of available nutrients, proper partitioning among vegetative and reproductive parts and

assimilation of photosynthates. The goal for narrow spacing would be to reduce

production costs by shortening the growing season in such a way that flowers are

produced at regular intervals and fewer bolls per plant would be compensate to maintain

yield. However, required plant population varies with location, environment and cultivar

(Siebert et al., 2006). Similarly, the findings of other researchers are in agreement with

our results (Bednarz et al., 2006; Bednarz, 2005; Dong et al., 2005; Nichols et al., 2004;

Guthrie, 1991).

Soil fertility and crop management are considered to be important factor to ensure

optimum yield in modern agriculture. Cotton crop has an indeterminate growth habit,

thus, non-judicious use of nitrogen fertilizer is correlated with excessive vegetative

growth that adversely affects yield. The genetic potential of a cultivar may be therefore,

achieved with judicious use of fertilizers in any cropping system. The essence of

managing cotton crop is to maintain a balance between the vegetative and reproductive

growth. Although an increase in nitrogen fertilizer caused significant delay in earliness,

but it produced taller plants with more fruiting points, more boll number, more boll

weight and lesser shedding percentage that resulted higher seed cotton yield. Moreover,

higher reproductive dry matter and reproductive-vegetative ratio long staple fiber with

more brightness were observed with increase in nitrogen. The highest seed cotton yield

223
was observed with the maximum nitrogen rate of 200 kg ha-1 (Fig. 3). Nitrogen is a

limiting factor and commonly added to meet the crop demand. Nitrogen management for

cotton is important in maximizing yields because environmental and production factors

influence its demand. Crops with nitrogen deficiency, suffers from reduced vegetative

and reproductive growth resulting in premature senescence and ultimate decrease in

yield. Nitrogen increases the leaf area expansion resulting in enhanced the efficiency of

light interception and higher assimilation. The yield of agricultural crops has been

strongly dependent on the supply of mineral nutrients, and thus, nitrogen is used to

exploit the full genetic potential of a crop (Sawan et al., 2006). These results are in

agreement with the findings of other scientists who reported that boll number, boll

weight, seed index and lint percentage increased with an increase in nitrogen (Alagudaral

et al., 2006;; Khan et al., 2005; Fritschi et al., 2003; Hassan et al., 2003; Bondada and

Oosterhuis, 2001; Boquet and Breitenbeck, 2000).

224
 SUMMARY

Plant morphology and genetic make up of a specific cultivar requires optimum sowing

time, plant spacing and judicious use of fertilizers to achieve sustainability in seed cotton

production. Thus, studies were carried out at the Central Cotton Research Institute,

Multan, Pakistan on silt loam soils during 2004-07.

Exp-I was conducted on silt loam soil having pH (8.09), EC (2.72 dSm-1) and organic

matter (0.82%) consisted of two cultivars; CIM-473 and CIM-482, three sowing dates;

May 10, June 01 and 20 at twenty days interval with three plant spacing of 15, 30 and

45cm during 2004. The cultivar CIM-473 showed significantly behaviour in terms of

phonological events with earliness, more fruiting points, intact fruits, boll number,

reproductive dry matter and lower shedding percentage that resulted in increased seed

cotton yield and lint percentage with more brightness. In contrast significantly higher boll

weight, seed index, yellowness and micronaire were observed in cultivar CIM-482. Delay

in sowing beyond on May 10 significantly decreased the number of fruiting points, intact

fruits, boll number and increased shedding percentage which resulted in decreased seed

cotton yield. However, crop sown on June 01 produced fiber with more brightness and

lower yellowness than early sown crop on May 10. Similarly, narrow spaced plants

produced significantly more reproductive dry matter, number of fruiting points, intact

fruits, boll number and higher seed cotton yield.

Exp-II was conducted during 2005 on silt loam soil having pH; 8.05, EC; 2.68 dSm1 and

organic matter; 0.84%. In the experiment two cotton cultivars CIM-473 and CIM-482

were sown on May 10 and June 01 with two plant spacings of 15 and 30 cm and four

nitrogen levels (0, 50, 100, and 150 kg ha-1). In this experiment, cultivar CIM-473

showed similar behaviour as that of last year by showing a significant earliness in terms

225
of phonological events, more number of intact fruits, boll number, seed cotton yield, lint

percentage, more reproductive dry matter, higher reproductive-vegetative ratio (RVR)

and less shedding percentage on both the sowing dates. Whereas significantly higher boll

weight and seed index were observed in CIM-482. Moreover, CIM-473 also produced

fiber with significantly more brightness and lower value of (fine) micronaire while CIM-

482 produced significantly more staple length, fiber uniformity ratio and elongation on

both sowing dates. Fiber maturity and higher yellowness (%) were observed only with

crops sown late on June 01. Again narrow spacing caused significant impact on hastening

of the earliness, produced higher number of fruiting points, intact fruits, boll number,

seed cotton yield, more reproductive dry matter, higher RVR value and maturity

percentage on both early and late sown crops while wider spacing resulted in higher boll

weight, more brightness and lower shedding percentage. Each increment of nitrogen

fertilizer caused significant delay in earliness, produced taller plants, more fruiting points,

boll number, boll weight that resulted higher seed cotton yield. Furthermore reproductive

dry matter and higher RVR were also observed with each increase in nitrogen in both

early and late sown crops. It is interesting that significantly the maximum number of

intact fruits and the least shedding percentage were observed with the highest nitrogen

rate. Moreover higher rates of nitrogen (100 and 150 kg ha-1) produced fiber with

significantly longer staple, more brightness than zero nitrogen application when crop

sown late on June 01.

Exp-III was also carried on silt loam soils with composition of pH; 8.06, EC; 2.67 dSm-1

and organic matter; 0.84% to find out the interactive effects of plant spacing (15 and 30

cm) with three levels of nitrogen fertilizer (0, 100 and 150 kg ha-1) on cotton crop were

evaluated during 2006. In this experiment, each increment of nitrogen significantly

increased the number of fruiting points, intact fruits, boll number and boll weight that

226
resulted in higher seed cotton yield. Further, nitrogen application showed an increase in

vegetative, reproductive and total plant dry matter production with higher value of RVR

through-out the crop growth. Significantly higher fiber strength, fiber maturity and lower

shedding percentage were also observed with nitrogen application. Again narrow spacing

showed a similar picture like that of previous studies and hastened the squaring,

flowering and boll split initiation and produced significantly higher number of fruiting

points, intact fruits, boll number, seed cotton yield, more vegetative, reproductive and

total plant dry matter with higher RVR value and fiber with slightly more brightness,

whilst significantly the highest seed index and fiber length were observed with wider

spacing.

Exp-IV was also conducted on silt loam soils having pH (8.04), EC (2.66 dSm-1) and

organic matter (0.85%). In this experiment cotton cultivars CIM-473 and CIM-496 were

sown on May 10 with four levels of nitrogen fertilizer i.e.0, 100,150 and 200 kg ha-1 and

a plant spacing of 15 cm during 2007. In this experiment, cultivar CIM-496 produced

significantly taller plants, higher boll number and boll weight that resulted higher seed

cotton yield. Both the cultivars showed a similar trend and again each increment of

nitrogen produced significantly taller plants, higher boll number and boll weight that

resulted higher seed cotton yield up till 150 kg N ha-1. However, the highest nitrogen rate

of 200 kg ha-1 slightly gave higher yield than 150 kg ha-1 but the differences were not

significant statistically.

227
 CONCLUSIONS

It is concluded from the present study that cultivar CIM-473 has a potential of bearing

higher boll number and lower shedding percentage that resulted in increased seed cotton

yield and lint percentage with more fiber brightness. The crop sown earlier on May 10

produced the higher number of fruiting points, more intact fruits and higher boll number

which resulted in increased seed cotton yield. Similarly, narrow spaced plants exhibited

earliness, higher number of fruiting points, more boll number and higher seed cotton

yield. Nitrogen fertilizer showed a better response to cotton crop and uptil 150 kg N ha-1

each increment of nitrogen gave a significant increase in height, number of nodes, boll

number, boll weight and seed cotton yield. However, the highest number of intact fruits,

the highest number of bolls and the lowest shedding percentage and the highest seed

cotton yield were achieved with the highest nitrogen rate of 200 kg ha-1. Moreover, the

fiber with the highest value of brightness was also recorded with the highest nitrogen

rate. It is therefore, suggested that growers may be promoted to sow the cultivar CIM-473

or any other cultivar of similar characters during the second week of May with narrow

plant spacing of 15 cm and nitrogen fertilizer must be applied at the rate of 150 kg ha-1 to

ensure the optimum yield in the region.

228
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 METEOROLOGICAL DATA

Meteorological data recorded at Central Cotton Research Institute, Multan

during the year 2004
Months
Parameter
May June July August SeptembeOctober
Max Temp. (oC) Mean 40.1 39.6 37.7 35.3 34.5 30.2
o
Min. Temp. ( C) Mean 25.7 29.0 29.2 27.3 24.6 18.4
8 AM Mean 45.1 59.2 71.3 84.4 78.5 76.4
Relative Humidity (%)
5 PM Mean 24.3 38.3 52.5 70.9 59.3 53.5
8 AM Mean 36.0 37.4 36.9 32.7 32.0 23.5
Soil Temp. (oC)/0 cm
5 PM Mean 46.9 47.7 47.0 39.8 39.2 30.6
Rain fall (mm) 2.3 17.2 0.5 71.3 0.4 1.0
Sunshine Hours (Total) 8.83 8.61 7.96 8.5 8.67 6.95
-1
Evaporation (cm day ) Mean 1.40 1.23 1.07 0.76 0.72 0.55

Meteorological data recorded at Central Cotton Research Institute, Multan

during the year 2005
Months
Parameter
May June July August SeptembeOctober
Max Temp. (oC) Mean 36.9 40.7 36.5 34.8 33.9 32.5
o
Min. Temp. ( C) Mean 23.7 28.7 29.0 28.3 25.1 17.9
8 AM Mean 48.6 55.1 78.5 78.4 82.2 79.3
Relative Humidity (%)
5 PM Mean 28.4 31.0 61.2 62.3 65.3 60.4
8 AM Mean 33.1 37.4 34.4 32.9 32.7 24.1
Soil Temp. (oC)
5 PM Mean 43.9 48.1 41.1 41.3 39.2 33.5
Rain fall (mm) 12.5 0.0 22.4 0.00 8.5 0.00
Sunshine Hours (Total) 8.98 9.21 8.32 9.48 9.00 9.46
-1
Evaporation (cm day ) Mean 1.18 1.27 0.89 0.96 0.67 0.59

241
 30
)

Meteorological data recorded at Central Cotton Research Institute, Multan

during the year 2006
Months
Parameter
May June July August SeptembeOctober
Max Temp. (oC) Mean 42.0 39.5 38.2 35.3 34.1 32.0
Min. Temp. (oC) Mean 27.9 27.2 30.2 28.3 25.2 21.2
8 AM Mean 51.9 61.0 70.4 79.8 78.1 81.1
Relative Humidity (%)
5 PM Mean 34.2 40.3 54.1 65.2 61.2 65.5
8 AM Mean 37.8 36.9 38.1 35.3 33.2 26.0
Soil Temp. (oC)
5 PM Mean 48.2 47.4 48.1 41.3 40.7 33.5
Rain fall (mm) 0.0 16.2 1.5 39.1 0.0 1.0
Sunshine Hours (Total) 7.90 8.40 7.68 9.21 9.55 8.39
Evaporation (cm day-1) Mean 1.27 1.18 1.12 0.84 0.70 0.53

Meteorological data recorded at Central Cotton Research Institute, Multan

during the year 2007
Months
Parameter
May June July August SeptembeOctober
Max Temp. (oC) Mean 39.4 38.9 36.7 35.7 34.6 32.3
o
Min. Temp. ( C) Mean 26.1 29.0 29.1 28.7 25.8 16.0
8 AM Mean 50.5 68.0 75.4 79.0 81.3 79.7
Relative Humidity (%)
5 PM Mean 33.6 47.7 58.4 82.9 68.5 63.8
8 AM Mean 36.0 36.2 35.7 35.9 32.7 24.2
Soil Temp. (oC)
5 PM Mean 43.9 45.0 43.6 43.9 39.7 34.4
Rain fall (mm) 0.0 17.9 15.9 2.7 28.0 0.0
Sunshine Hours (Total) 9.68 9.05 8.55 8.87 8.36 9.20
-1
Evaporation (cm day ) Mean 1.21 1.21 0.90 0.83 0.53 0.46

242