SEMINAR-IION
Leaf reddening in cotton and its management practices
Presented by:
SANTHOSH, U. N.
PG10 AGR 2032
Dept. of Agronomy
University of agricultural
sciences, Raichur (karnataka)
Sequence of presentation
• Introduction• Changes in Leaf reddening • Factors affecting leaf reddening• Management practices• Conclusion
Cotton
Bt-Cotton Approved
26 March 2002: A Landmark in India
India’s first transgenic crop
Bt Cotton
Bt-cotton area & cotton production in India620 Bt-cotton hybrids & 1 Bt variety have been released so far
New Hybrids
Bt Cotton area lakh ha
What is leaf reddening ?
• Reddening of leaves is a physiological disorder where, in first the leaves
turn red. It starts on the fringes of the leaves or in patches or inter
vascular portion
• The leaf reddening is the result of an unfavorable interaction of varieties,
nutrient supply and environmental condition
• The malady is mostly observed during boll development stage or later but,
occasionally during squaring to flowering stage
Leaf Reddening Index (LRI) Grades Details
0 When all the leaves are green or < 3 leaves showing the signs of reddening
1 when 3 leaves / plant are showing reddening
2 when > 3 leaves / plant showing reddening but young leaves were green
3 when all the leaves are showing reddening in patches / plant
4 when whole plant looks red
Dastane (1952)
Leaf reddening not a new and sudden disease/disorder
Butler reported occurrence of leaf reddening in hirsutum cotton as
back as 1909 when American cotton was introduced in India.
place scientists Reported year
North America Burt & Haidar 1919
New Guinea Evans 1926
Nigeria Jones & Masar 1926
Netherland Sampson 1927
Uganda Arnon 1931
West Punjab & Sindh Dastur & Kanwar Singh 1947
Karnataka Dastur et al. 1952
It is known by several names
Red Leaf Disease (most common)
Lalya in Maharashtra
Lal Pan in Gujarat
Copper top
Red wilt/ Anthocynosis in many countries
Bronzing
Sudden wilt/ Phloem wilt in U.S.
Stages of development or levels ofseverity of leaf reddening.
Stage or severity Above-ground symptoms
Early or slight Lower leaf angle (wilting) and higher leaf
temperature in upper canopy than in normal plants
Mid-stage or moderate
plus reddening of upper canopy (stem or leaf) and
abnormal shedding of fruits
Late stage or severeplus necrosis of stem tissue or whole plants
What changes occur during leaf reddening
Morphological
The leaf reddening initially seen in mature leaves and gradually spreads throughout the canopy
The affected leaves become brittle with buckling and crinkling between vein and cupping under the leaf lobes. This is followed by necrosis and pre-mature shedding
Reddened plant produce smaller and fewer leaves
Bolls turn red and crack pre-maturely
The overall plant growth is stunted
Upper surface of leaf showing reddening
Lower surface of leaf showing reddening
Physiological
Reduced rate of photosynthesis (23.5 – 53.3%) due to decreased photochemical reaction and stomatal limitation (Velikova et al., 2002)
Reduced rate of respiration (3.6 – 16.1 %)
Reduced rate of transpiration (5.4 – 16.8 %)
Low root sugar content
Large starch granules in chloroplast of red leaves
Biochemical
Degradation of chlorophyll / Anthocynin accumulation
Increased carbohydrates contents
Increased free amino acids and protein-nitrogen
Increased leaf tannin / phenolic content (Chakravorthy, 1980 and Taneja et al., 1984)
Increased Peroxidase activity (Edreva et al., 2002)
Increased Proline content (Chakravorthy, 1980)
Reduction in pH of cell sap (Chakravorthy, 1980)
Reversible change in membrane permeability
Nutrients
Reduce uptake of K (Yagmur et al., 2009)
Accumulation of Na (Yagmur et al., 2009)
Reduced Nitrogen content (Dastur, 1968 and Bhatt & Patil, 1976)
Low Mg content (Pagare and Durge, 2010)
Reddening intensity increases with decreasing N & P content (Ishag et al., 1987)
Factors affecting leaf reddening
Leaf reddening
Environmental factors
Nutritional factors
Sucking pests Soil factors
Production aspects
Pathogenic aspects Physiological aspects
Vijay Kumar Ghante et al., 2010
The Reasons For ReddeningClimate
Low night temperature <16°C simulates in anthocynin formation (Dastur, 1968)
Wide differences in day and night temperature (>20°C) with day temperature >38°C may lead to reddening
High wild velocity leading to desiccation injury (Dastur, 1968)
High light intensity (Combrink, 1988)
High crop ET demand, depleting leaf/ soil moisture aggravate reddening intensity (Taneja et al., 1984)
Water stress of -300 kpa caused premature senescence with induction of anthocynin, synthesis in petiole, stem and leaves (Combrink, 1988)
High water table and soil compaction causing low O2 in rhizosphere.
Plant stresses
• Environmental stress factors
such as cool, cloudy weather and low temperatures in the late season can inhibit the crop's ability to take up potassium, even in soils that are not K deficient
• Soil compaction can also restrict K uptake
• Water logging from rain or irrigation is another stress that prevent uptake in K rich soils
• Inadequate N nutrition for a highly loaded crop
Green leaf
Bad soil conditions
Poor aeration
Reduced uptake of mineral
Enzyme inactivation
Red leaf occurrence
A flow chart indicating red leaf occurrence due to bad soil conditions
Dhopte ( 1985)
Nutritional factors
N deficiency in leaf at flowering and boll development causes leaf reddening, if N falls <2.0 - 2.5% depending upon crop growth (Bhatt, 1996 and Dastur, 1968). Low leaf N could be due to Low soil N availability Impaired N uptake due to moisture stress or water logging Diversion of leaf N to developing bolls Synchronized boll development and high N demand
Petiole K <4% and leaf blade K <1% favour senescence, subsequently leaf reddening
Deficiency of micro nutrient, particularly Zn
Low magnesium content in leaf (Perumal & Subramaniam, 1979 and Bhatt et al., 1982)
Magnesium Deficiency
Magnesium deficiency can be expected in calcareous soils, specially when high amounts of single super phosphate and potassium are applied
Reddening of older and middle leaves is an indication for magnesium deficiency
Lower leaves become purplish red with distinct green veins
REMEDIES:
Soil application of magnesium sulphate @ 25 kg/ha
Foliar spray of magnesium sulphate @ 0.5% or 1.0% at flowering and reproductive stages of crop growth
Potassium Deficiency
• yellowish white mottling• leaves become light yellowish green with
yellow specks• specks become necrotic, causing the
leaves to appear rusted or dotted• After peak bloom, K deficiency
symptoms first appear on the younger mature leaves in the upper third of the canopy.
• Pre-mature shredding of leaves prevents boll development, resulting in small immature bolls
REMEDIES :
• Apply potassium in 3 equal split doses at 30, 60 and 90 DAS through either murate of potash or potassium sulphate
• Use foliar spray with potassium bearing inorganic fertilizers
Nitrogen Deficiency
produces small, pale yellow leaves, reduced stalk height, and lesser number of vegetative branches
Bolls shed in the first 10-12 days after flowering
It results in yellowing, premature reddening
REMEDIES:Grow leguminous crop as intercrop to correct edaphic conditions and to augment biological nitrogen fixation process
Top dressing with inorganic nitrogen fertilizer @10 - 20 Kg N/ha
Foliar spray of nitrogen fertilizers @ 0.5% N
Phosphorus Deficiency
Affects growth rate which ultimately results in stunted plants with dark leaves
delayed fruiting, reduced flowering, boll setting and delayed maturity of set bolls
In certain severe cases, the foliage becomes reddish to purple in colour
Insect and pathological factors
Severely jassid damaged varieties show symptoms similar to leaf reddening
Viral etiology has been proved for red leaf disease in Brazil (Costa)
Anthocyanin production by cotton leaves is response to an unsuccessful challenge by X.compastris pv. malvacerum is a response to bacterial blight (Kangatharalingam et al., 2002)
Cotton plant affected with Jassids
Thrips
White fly, Aphids
Alternaria leaf spot Foliar fertilizer spray injury
Fusarium wilt Verticilium wilt
Genetic Factors
Leaf Reddening is observed only in tetraploid and rarely in diploid indigenous cottons
Certain hybrids are very prone to reddening than others
The expression of reddening depends on the interaction of genotype and environment
The inheritance of anthocyanin pigmentation is monogenic in nature (Sandhu et al., 1987)
Reddening Symptoms on affected plants
Chlorosis of foliage with bronze wilt Plants with end of row affected with bronze wilt
Wilt of foliage Rosis associated with bronze wilt
Leaf reddening in Bt Cotton
Leaf reddening in Bt Cotton
PHYSIOLOGICAL RESULTS
Stages
TCHH 4 MRC 6301 NSC 145
Healthy leaves
Reddening affected leaves
Healthy leaves
Reddening affected leaves
Healthy leaves
Reddening affected leaves
Square formation
stage 2.07 1.19 2.03 1.18 2.09 1.20
Boll development
stage 1.53 0.96 1.51 0.94 1.57 0.98
Boll bursting stage
1.36 0.71 1.32 0.67 1.37 0.73
Chlorophyll content of leaves (mg/g)
Pagare & Durge, 2010
Stages TCHH 4 MRC 6301 NSC 145Healthy leaves
Reddening affected leaves
Healthy leaves
Reddening affected leaves
Healthy leaves
Reddening affected leaves
Square formation stage
3.85 8.91 3.90 8.96 3.76 8.77
Boll development stage
4.92 10.85 5.12 10.98 4.90 10.92
Boll Bursting stage 5.92 12.72 5.97 13.40 5.88 12.52
Anthocynin content of leaves (ppm)
Pagare & Durge, 2010
Carbohydrates content of leaves (%)
Stages TCHH 4 MRC 6301 NSC 145Healthy leaves
Reddening affected leaves
Healthy leaves
Reddening affected leaves
Healthy leaves
Reddening affected leaves
Square formation stage
3.85 4.84 3.70 4.70 3.97 4.87
Boll development stage
3.56 4.43 3.37 4.30 3.70 4.74
Boll bursting stage
2.90 3.14 2.80 3.22 2.98 3.31
Pagare & Durge, 2010
Changes in leaf anthocyanin content of cotton genotypes at
different stages
Genotypes 100 DAS 132 DAS 162DAS
MCU-5 3.95 5.52 8.16
DCH-32 1.32 3.26 9.62
RKR-4145 3.11 5.24 6.57
LAXMI 4.10 6.29 7.99
SHARADA 2.89 5.04 6.09
LRA-5166 2.26 3.96 4.52
JK-119 2.08 4.89 5.97
RAMPBS-218 1.81 2.27 2.86
RAMPBS-296 0.88 1.79 2.34CD @ 5 % 1.24 1.05 1.29
Chimmad and Panchal (1999)
Changes in leaf anthocyanin content in top, middle and bottom canopy levels at different stages
Canopy levels 100 DAS 132 DAS 162DAS
Top 2.99 4.48 5.72
Middle 2.79 4.34 5.45
Bottom 2.90 4.82 4.75
Chimmad and Panchal ( 1999)
Photosynthetic rate, stomatal conductance and transpiration rate of cotton leaves with and without reddening symptoms
variants Photosynthetic rate
Stomatal conductance
Transpiration rate
Control leaf 32.3 0.553 2.855
Severe symptoms of reddening
6.43 0.036 0.620
Wilting plant 7.13 0.0046 0.078
C.D.(p=0.05) 1.108 0.078 0.313
Cv(p=0.05) 6.2 14 12
Naidu et al. ( 2011)
NUTRITIONAL RESULTS
Nitrogen content of leaves (%)
Stages TCHH 4 MRC 6301 NSC 145Healthy leaves
Reddening affected leaves
Healthy leaves
Reddening affected leaves
Healthy leaves
Reddening affected leaves
Square formation stage 2.85 1.21 2.66 1.17 2.86 1.30
Boll development stage
2.39 1.22 2.36 1.12 2.43 1.32
Boll bursting stage 2.80 0.84 1.75 0.76 1.84 0.86
Pagare & Durge, 2010
Magnesium content of leaves (%)
Stages TCHH 4 MRC 6301 NSC 145
Healthy leaves
Reddening affected leaves
Healthy leaves
Reddening affected leaves
Healthy leaves
Reddening affected leaves
Square formation stage
1.39 0.88 1.32 0.85 1.37 0.89
Boll development stage
1.09 0.82 1.08 0.80 1.09 0.83
Boll Burstingstage
0.98 0.70 0.97 0.64 0.99 0.73
Pagare & Durge, 2010
Changes in leaf Nitrogen content (%) of cotton genotypes at different stages of reddening
Genotypes 100 DAS 132 DAS 162DAS
MCU-5 2.83 2.79 1.73
DCH-32 3.04 2.58 1.85
RKR-4145 2.99 2.67 2.09
LAXMI 2.81 3.06 2.45
SHARADA 2.74 2.75 2.13
LRA-5166 2.83 3.11 2.43
JK-119 2.68 2.83 2.30
RAMPBS-218 3.07 2.80 2.69
RAMPBS-296 3.29 2.76 2.81
CD @ 5% 0.11 0.23 0.21
Chimmad and Panchal ( 1999)
Ishag et al.1986
EFFECT OF POTASSIUM
Effect of soil and foliar application of Potassium on growth and yield parameters of cotton
Treatments No. Of monopodials/plant
No. Of sympodials/plant
No. Of bolls/plant
Boll weight ( g)
N P only ( No K) 1.4 19.3 15.3 4.75
NPK (RDF) 2.2 21.9 17.5 5.03
NPK + K – foliar spray at early boll formation
2.1 22.5 18.8 5.30
NPK + K- foliar spray at peak boll formation
2.4 23.0 18.8 5.35
NPK + K- twice foliar sprays each at early and peak boll formation
2.6 23.0 20.6 5.48
S.Em ± 0.24 23.9 0.57 0.10CD @ 5% 0.73 NS 1.75 0.32
Aladakatti et al. (2010)
Dry matter production and nutrient uptake by cotton (kg/ha)
Treatment Dry matter N uptake P uptake K uptake
Control (water spray) 5551 69.6 12.30 67.72
KNO3 (2%) – 4 sprays 6400 80.7 14.37 78.15
KNO3 (3%) – 4 sprays 5510 69.3 12.19 67.22
Soil application of K – 4 splits 7120 89.2 14.76 87.40
K (100%) applied as basal 6161 77.30 13.65 75.32
DAP (2%) at PF and BDS – 2 sprays 6027 75.3 15.36 74.46
KCl (1%) – 4 sprays 5631 70.6 12.64 68.70
SED 530 6.6 1.17 6.47
CD(p=0.05) 1075 13.4 2.37 13.12
Srinivasan and Ramalingam., 2011
Treatments Seed cotton yield
(kg/ha)
No. Of open bolls/plant
Ginning (%)
Boll weight (g)
NP (120:50) 1335 17.83 32.18 3.25
NPK (120:50:40) 1381 20.00 33.82 3.46
T2+ K foliar at initiation of boll formation
(5kg/ha)
1433 23.50 34.89 3.74
T2+ K foliar at peak boll formation
1408 22.67 33.72 3.67
T2+ K foliar at initiation and peak boll formation
1445 28.83 35.89 3.99
CD @ 5% 32.27 1.51 2.09 0.18
Yield, yield attributes and quality of Cotton as influenced by foliar application of Potassium
Sharma and sunder Singh (2007)
MICRO NUTRIENTS SPRAY RESULTS
Treatments Bolls/pl Boll wt.(g)
Yield/pl (g)
Yield (kg/ha)
RDF only 15.6 5.13 69.6 2103
0.1% boron spray 17.8 5.07 74.8 2149
0.5% ZnSO4 spray 17.7 5.35 74.8 2213
1% MgSO4 spray 18.7 5.12 77.2 2174
1% MnSO4 spray 18.8 5.15 76.7 2200
0.5% FeSO4 spray 17.4 4.93 75.6 2235
0.5% ZnSO4 spray + 1% MgSO4 spray 19.6 5.22 84.1 2438
0.5% ZnSO4 + 1% MgSO4 +0.5% FeSO4 spray 19.4 5.25 81.6 2312
0.5% ZnSO4 + 1% MgSO4 + 0.5% FeSO4 + 0.1% boron spray
18.0 5.18 78.2 2314
CD @ 5% NS NS NS 189
Yield parameters and yield of Bt-cotton as influenced by foliar application of Micronutrients
Anon., 2007
Foliar applications Plant Height
Sympodia/plant
Bolls/plant
BollWeight (g)
Seed cotton yield (kg/ha)
Magnesium sulphate (0.5%)
165.2 28.02 35.4 4.19 1482
Magnesium sulphate (1.0%)
160.6 27.53 39.2 4.21 1595
Zinc sulphate (0.2%) 156.2 24.93 38.7 4.30 1512
Ferrous sulphate (0.2%) 152.5 23.48 37.8 4.19 1557
Manganese sulphate (0.2%)
158.4 26.50 37.4 4.29 1607
Boric acid (0.2%) 155.4 25.08 25.08 4.19 1575
Control 151.8 24.40 24.40 4.17 1271CD @ 5% 8.75 0.42 3.38 0.22 123.2
Effect of foliar application of nutrients on growth parameters of cotton
Ratna kumari and Hema., 2009
Effect of micronutrient fertilizers on per plant growth
Treatment Height (cm)
squares LAI Dry weight (kg/ha)
MgSO4 @ 50 kg/ha-soil 63.4 11.9 2.7 1709
MgSO4 @ 0.5% -foliar 70.3 15.6 2.9 2114
ZnSO4 @ 50 kg/ha-soil 67.5 15.0 2.8 1906
ZnSO4 @ 0.5% -foliar 62.5 12.8 2.5 1625
FeSO4 @ 50 kg/ha-soil 66.2 14.0 2.4 1654
FeSO4 @ 0.5% -foliar 69.2 12.8 2.7 1657
Borax @ 5 kg/ha-soil 58.8 13.3 2.7 1982
Borax @ 0.5% -foliar 65.2 14.0 2.5 1638
Control 66.2 14.8 2.3 1663
Sankaranarayanan et al., 2010
What loses are caused by Leaf Reddening….
If the reddening occurs in early stages of squaring to flowering the losses may be as high as 60 - 75%, if corrective measures are not taken.
Usually reddening occurs post bolling stage when the losses could be 15 - 25% depending upon severity.
More than actual losses, the phenomenon disturbs the psyche of the cultivator.
MANAGEMENT PRACTICES
Yield and yield parameters as influenced by management of leaf reddening in Bt-cotton
Treatments Bolls/plant Boll wt (g)
Yield/plant (g)
Kapas yield (kg/ha)
RDF only 21.6 5.20 106.1 3081
RDF (on soil test) 21.8 5.50 100.7 2976
T2+ 3sp 1% MgSO4 at 80, 100 and 120 DAS 25.6 5.40 125.7 3315
T2+ FYM 10 t/ha+ 1sp 2% urea and 1 sp 1% urea + 1% MgSO4 FL to BD stage
23.9 5.62 126.3 3382
T2+ FYM 10 t/ha + 2 sp % KNO3+ 2% DAP FL to BD stage
26.3 5.78 132.1 3327
CD @ 5% NS NS 14.8 242
Anon., 2009
Economics as influenced by management of leaf reddening in Bt- Cotton
Treatments Gross returns Rs/ha
Net returns Rs/ha
B:C
RDF only 86283 57620 3.01
RDF (on soil test) 83316 54865 2.93
T2 + 3sp 1% MgSO4 at 80, 100 and 120 DAS 92822 62942 3.11
T2 + FYM 10 t/ha +1sp 2% urea and 1 sp 1% urea + 1% MgSO4 FL to BD stage
94702 64638 3.15
T2 + FYM 10 t/ha + 2 sp % KNO3 + 2%DAP FL to BD stage
93167 61813 2.97
CD @ 5% 6781 NS NS
Anon., 2009
EFFECT ON SEED COTTON YIELD
Seed cotton yield (q/ha) and Red Leaf Index (RLI) at different stages of different Genotypes
Genotypes Seed cotton (q/ha) 100 DAS 132 DAS 162DAS
MCU-5 12.03 1.85 3.15 3.37
DCH-32 13.37 1.58 3.33 3.77
RKR-4145 16.93 2.37 3.58 3.83
LAXMI 15.95 3.15 3.82 3.53
SHARADA 23.18 1.85 2.25 3.25
LRA-5166 17.69 1.62 2.07 2.57
JK-119 16.10 1.53 1.48 3.67
RAMPBS-218 22.30 0.77 1.42 2.07
RAMPBS-296 23.15 0.47 0.97 1.27
Chimmad and Panchal ( 1999)
Remedial Measures
Maintain a good soil organic carbon at least ≥ 0.5% by adding F.Y.M, composting and green manure.
Apply irrigation at closer interval during peak bolling.
Avoid high temperature period synchronizing with high boll load.
Use judicious amount of fertilizers & micronutrient at right time depending on soil test/critical leaf/ petiole limit.
If reddening occurs apply 2% DAP/ 1-2% Urea with 0.5-1% MgSO4, repeat after 10 days. This can be done as a preventive measure as well.
Use suitable and resistant variety for the area. Some varieties are highly prone to reddening e.g. MECH-1, MECH-4, JKCH-1, DCH-32 (Sahay, 1988). RCH-2 Bt, Brahma, NCS-145 are often show reddening.
In many cases use of 2-3% KNO3 , 3 - 4 times during squaring to bolling has been found effective in managing reddening.
Foliar application of CCC helps in managing greenery and prevents reddening.
Cultural practices make RLS less severe
• Plant at recommended time so as not to coincide with high soil
temperatures regime during fruiting.
• Apply balanced fertilizers at appropriate time and dosage.
• Fertilize with phosphorus, potassium and sulphur before planting when soil
tests indicate deficiencies.
• Prevent water stress by irrigating sufficiently in irrigated areas and by
proper water conservation methods in rain fed areas.• RLS is an annual problem that reduces yield, quality and economic returns
to producers.
Multi Disciplinary Approach
Growing of leaf reddening tolerant Bt hybrids
Soil test based site specific fertilizer application
Timely application of fertilizers
Foliar sprays of multi micronutrient mixtures at square and boll formation stage
Management of sucking insect and mite pests
Management of wilt diseases
Vijay Kumar Ghante (2010)
Future Prospects
Development of reddening resistant hybrids which are suitable to that cotton growing regions.
Bring improvement over through current soil and foliar nutrition management practices.
Improvement in agronomic package and cultivation practices like doses of fertilizers, pest control, irrigation methods, sowing time etc.
Detailed studies on physiological and biochemical changes and management practices essential
Leaf reddening cannot be reversed but depending upon the inciting factors, preventive or corrective measures can be resorted to keep
this disorder under check.
CONCLUSION
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