About 3 million farmers are engaged in cotton cultivation in the state mostly in backward region of Marathwada and Vidarbha. Cotton enjoys a free eminent status among all cash crop in the country, being a principal raw material for a flourishing textile industry which accounts for nearly 20 per cent of the total national industrial production and provides employment to over 15 million people.
In Vidarbha region, cotton is the most important cash crop grown on an area of 13.00 lakh ha with production of 27 lakh bales of cotton (2008-09). The productivity of cotton is low (350 kg/ha) in Vidarbha as compared to national (502 kg/ha). The main reason for the low productivity of cotton in Vidarbha is its dependence on the monsoon rain and about 95 to 98 per cent area is under rain-fed cultivation.

The “Cotton Research Unit” was established in the university with inception of ICAR centre under “All India Coordinated Cotton Improvement Project” in 1972 for development of high yielding varieties and hybrids of American and Deshi cotton suitable for rain-fed situation of Vidarbha region and development of low cost cultivation technology along with effective and cheapest plant protection measures.

• To develop high yielding varieties and hybrids suitable for rainfed situation in Vidarbha region.

• To develop suitable Agro-techniques to achieve maximum yield and monitory benefit.

• To develop effective and cheapest plant protection schedule.

• Development and promotion of medium and long linted diploid cottons (G.arboreum and G.herbaceum)

• Development and promotion of Bt transgenic cotton for bollworm resistance.

• Development of production technologies for Bt cotton and improvement of water and nutrient use efficiency with precision farming techniques.

• Development and validation of IPM, IRM strategies for conventional and Bt cotton under different ecosystem.

• Nucleus and breeder seed production of cotton varieties and parents of hybrids.

• Insect pest resistance management.

• National information system for pest management-Bt-cotton.

COTTON AGRONOMY

A. Sowing Time:

1. Pre monsoon irrigated cotton should be sown between 20th to 30th May.
2. Dry Sowing of straight varieties were found beneficial to increase Seed Cotton Yield over monsoon sowing.
3. For monsoon sowing, early sowing between 24th and 25th meteorological week (11th to 24th June) was found optimum. Early sowing with commencement of monsoon rains is desirable. Delay in sowing from optimum time of sowing even by a week reduces the seed cotton yield to the extent of 10 to 20 per cent.
4. Under limited availability of water, this Cotton Research Unit has developed a low cost technology popularly known as ‘crow-bar technology’ through which sowing can be achieved with least amount of water. This technology gives 70 to 100 per cent more yield than monsoon sowing. This technique was further refined and recommended as below:
   a) Apply one third of Nitrogen and full dose of P2O5 and K2O of the recommended dose (100:50:50 Kg NPK ha-1) at the time of sowing and remaining Nitrogen in two equal splits (30 and 60 days after sowing).
   b) It was also found that 40 per cent reduction in water application did not significantly reduce the yield over normal crow-bar method.
5. Raising of cotton seedlings in polythene bags and subsequently transplanting in the field after commencement of monsoon increased the cotton yield by 40 per cent as compared to monsoon sowing.

B. Planting Pattern and Plant Population:

1. Paired row planting (90 X 30 cm) of Hirsutum cotton with 50 Kg Nitrogen + 25 Kg P2O5 ha-1 with 56 thousand plants per hectare gave optimum yield of seed cotton.
2. A dwarf and early duration variety AKH 081 responded well to higher plant population. Hence spacing of 60 X 15 cm is recommended for this variety.
3. For getting maximum seed cotton yield a sowing distance of 60 X 30 cm and fertilizer dose of 50:25:0 NPK kgha-1 are recommended to Hirsutum cotton variety PKV Rajat (AKH 84635)
4. For cotton hybrid CAHH 468 a sowing distance of 60 X 90 cm and fertilizer dose of 50:25:25 NPK kgha-1 are recommended under rainfed condition.
5. Under rainfed condition sowing distance of 60 X 60 cm and fertilizer dose of 50:25:25 NPK kgha-1 are recommended to American cotton hybrid PKV Hy 4 and PKV Hy 5.
6. A sowing distance of 60 X 15 cm and fertilizer dose of 30:15:0 NPK kgha-1 are recommended to Arboreum cotton verities AKA 5, AKA 7 and AKA 8 for getting maximum seed cotton yield under rainfed condition.
7. For mechanical cultivation a seeding distance of 96 X 30 cm is recommended to improved cotton variety PKV Rajat for getting maximum yield under drip irrigation.

C. Soil and Rain Water Management:

1. Method of paired row planting with opening of deep furrows at 60 to 70 days after sowing was effective in increasing the yield. The method of ridging with every inter-culture was also beneficial.
2. On sloppy land sowing on ridges on 0.2 per cent slope gave more yield than sowing across the slope.
3. Opening of furrows (after two rows) at seeding or at 30 days after sowing is essential for improving moisture status of the soil and boosting crop yield in both contour sowing and sowing across the main slope.
4. From the toposequance study of micro water shed, it was observed that on a sloppy field instead of growing cotton crop on entire field, it is profitable to take cotton on upper toposequance (80 % area) and soybean – chick pea crop sequence on lower toposequance (20 % area).
5. In shallow soil (soil depth less than 22 cm) it is recommended to sow a dwarf and early cotton variety AKH 081 at 60 X 15 cm spacing for getting higher seed cotton yield under rainfed condition instead of cotton hybrids and other varieties.
   6. Two protective irrigations at flowering and boll setting increased the yield by 16.8 per cent over no protective irrigation treatment.

D. Fertilizer Management:

1. A fertilizer dose of 100:50:50 NPK kgha-1 is recommended for getting maximum seed cotton yield of irrigated hybrid cotton (pre-monsoon sowing).
2. Under rainfed condition a fertilizer dose of 50:25:25 NPK kgha-1 is recommended for hybrid cotton.
3. For Hirsutum straight varieties a fertilizer dose of 50:25:0 NPK kgha-1 is recommended
4. A fertilizer dose of 30:15:0 NPK kgha-1 is recommended for Arboreum varieties.
5. Basal dose of fertilizer should be applied at the time of sowing. If delayed by 15 and 30 days, reduced the yield by 6.0 and 14.3 per cent respectively.
6. A spot application of manures and fertilizers (RDF) to cotton crop is advantageous.
7. Fertilizer application by ring method or spot application at three places increased the yield by 12.2 and 10.5 per cent respectively as compared to broadcasting method.
8. Among the various Nitrogen management practices half of the recommended N at sowing and half at square formation recorded maximum seed cotton yield and cost benefit ratio of rain fed cotton.

E. Integrated Nutrient Management:

1. Inoculation of seed with azotobactor bio-fertilizer recorded 7.9 per cent increased seed cotton yield of deshi cotton variety AKA 8401 than control. The treatment having recommended dose of Nitrogen gave 11.0 and 29.3 per cent higher seed cotton yield respectively over 75 per cent and 50 per cent recommended Nitrogen application.
2. Application of FYM @ 5 t ha-1 along with low fertilizer dose of 25:12.5 N and P ha-1 is recommended for cotton variety AKH 081 grown under shallow soil (less than 25 cm) to get maximum monetary benefit in rainfed condition.
3. An application of 50 per cent RDF (25:12.5 kg N and P ha-1) and either FYM or glyricidia green foliage lopping at 30 days after emergence @ 5 tha-1 is recommended to get higher seed cotton yield and net monetary returns with the added benefit of improving physico-chemical properties of soil under rainfed condition.
4. An organic and in-organic fertilizer experiment of treatment having recommended dose of fertilizer (RDF) recorded more yield followed by 50 per cent RDF + 5 t FYM ha-1 and 50 per cent RDF + glyricidia foliage lopping compared to other treatments. Organic manure resulted in increasing organic carbon content and available N and P2O5 content of soil.

F. Weed Management:

1. A critical period of weed crop competition was found to be as 3 to 9 weeks after sowing during which it is necessary to keep the crop weed free for getting higher yield. A loss in seed cotton yield under unweeded control was to the extent of 85 per cent when compared with normal hand weeding.
2. Normal weeding and inter-culture recorded maximum seed cotton yield. A Pre and post emergence spray of diuron weedicide @ 0.75 kg ha-1 was effective in controlling weeds as compared to other chemical weed control treatments.
3. For control of weeds and increase in seed cotton yield application of 1.5 kgha-1 of pendemethalin or fluchloralin combined with one weeding or one hoeing at 30 days after sowing is recommended.
4. Fluchloralin @ 1.5 kg a.i.ha-1 + one hoeing 30 days after sowing is recommended for weed control in cotton – green gram interculturing system.

G. Intercropping:

1. Intercrops like green gram, black gram, soybean and groundnut reduced the yield of seed cotton as compared to sole cotton crop. Yield reduction was more with soybean as intercrop. Groundnut and green gram were observed to be the good intercrops in cotton (AHH 468) for getting maximum monetary returns.
2. Green gram and black gram are identified as suitable intercrops in Arboreum cotton variety AKA 8401 (90 X 20 cm spacing).
3. The seed cotton yield was maximum in sole cotton crop and it was reduced by 9.3, 24.6 and 50.5 per cent when intercropped with black gram, green gram and soybean respectively. However GMR was higher in cotton + green gram and cotton + black gram as compared to sole cotton in variety PKV 84635 (Rajat).
4. Sowing of black gram and green gram as intercrops in early and dwarf cotton variety AKH 081 is recommended to get higher monetary returns.

H. Cropping System Research:

1. For getting higher monetary returns and meeting the need of food, fodder and fuel of farmers cotton + sorghum + pigeon pea + sorghum (6:1:2:1) three tier intercropping system is recommended under rainfed situation.
2. Cotton + green gram (1:1) intercropping system recorded higher GMR than sole crop
3. Intercropping in cotton variety MCU 5 with green gram and cowpea with recommended dose of fertilizer to cotton crop was found beneficial on monetary basis as well as for yield stability
4. Cotton – groundnut (summer) crop sequence gave highest net returns and has been recommended for getting higher monetary returns under irrigated condition with adequate inputs.

I. Crop Canopy Management:

1. Two sprays of 2 per cent urea concentration with planofix (1 ml in 4.5 litre water) at flowering and boll formation stages found to be promising for getting higher yield.
2. Two sprays of planofix (NAA) at the commencement of flowering and 50 per cent flowering should be given to get high yield of seed cotton.
3. Foliar spraying of 2 per cent urea at flowering and 2 per cent DAP at boll development stages recorded maximum hybrid seed production followed by two sprays of urea 2 per cent + DAP 2 per cent combination.
4. In detopping experiment it was observed that seed cotton yield under manually detopping of PKV Rajat at flowering and no detopping were statistically similar under rainfed situation. Spraying of cycoceal did not show favourable influence in respect to seed cotton yield, however plant height was significantly reduced by 14 to 29.6 per cent with the use of cycoceal. Spraying of 20 ppm NAA and 2 per cent urea at flowering and 2 per cent DAP at boll development stages produced 16.7 and 18.3 per cent higher seed cotton yield over control. Cycoceal spraying treatment resulted in maximum square production but boll retention percentage was maximum with detopping treatment.
5. For cotton crop 4.5 ppm available iron content in soil and 281 ppm in youngest mature leaf at square initiation stage be considered as critical levels for application of iron.
   

COTTON ENTOMOLOGY

A. Economic Importance:

The yield losses caused by sucking pests, bollworm, bollworms and sucking pests were 4.61 per cent, 51.30 per cent and 51.53 per cent respectively indicating the importance of control of bollworms in cotton production.

B. Chemical Control of Pests:

1. Sucking Pests:

• For the control of thrips application of 0.2 % carbaryl + 0.1 % BHC followed by 0.1 % carbaryl + 0.2 % BHC was found effective.
• Considerable reduction in the population of aphids was observed by the use of 0.2 % malathion + 0.04 % endrin followed by 0.04 % malathion + 0.1 % carbaryl.
• Effective control of jassids could be obtained by the use of 0.1 % carbaryl followed by 0.04 % malathion + 0.1 % carbaryl in combination.
• While studying the performance of new insecticides against sucking pests of cotton it was observed that Helitox (0.2 %), Phosphamidon (0.02 %), Monocrotophos (0.03 %) and Carbaryl (0.2 %) were found promising amongst the insecticides tried.
• Monocrotophos 0.06 % was found to be most effective in controlling the nymphal population of aphids, jassids and thrips in cotton.

2. Bollworms:

• Application of monocrotophos at 0.1 % and 0.12 % was found effective in controlling bollworms of cotton.
• Quinalphos 0.05 %, Carbaryl 10.0 % dust @ 20 kg ha-1, Sevimol 0.2 %, Phosalon 0.05 %, Endosulfan 4 % dust @ 20 kg ha-1, Monocrotophos 0.06 %, Dicrotophos 0.05 % and Tamaron 0.1 % were found effective in controlling the bollworms of cotton.
• From the studies to see the efficacy of modern synthetic pyrethroids in comparison with Carbaryl (0.2 %) against bollworm of cotton (Variety H - 4), the treatment with Cypermethrin (0.01 %) was the best followed by Fenvalerate (0.01 %), Decamethrin (0.0025 %), Permethrin (Permasect) 0.01 % and Permethrin (Ambush) 0.01 % in order of merit.
• Spraying of synthetic pyrethroids alternated with organo-phosphates was recommended for the control of bollworm complex on cotton on the basis of trials conducted for three years.
• Studies on the efficacy of newer insecticides against cotton bollworm (Variety PKV Hy 2) indicated that the treatment with Flucythrinate (0.005 %) was the best followed by decamethrin (0.002 %) and fenpropethrin (0.015 %) and were at par with each other.
• Alphamethrin 25 g. a.i. per hectare was recommended for control of bollworm complex on cotton.
• Spraying of Spinosad 45 SC @ 0.01 % for the management of American and spotted bollworm on cotton and beta-cyfluthrin 2.5 EC @ 0.0025 % for the management of pink bollworm is recommended.

C. Integrated Pest Management:

1. From the studies on determination of economic threshold level of bollworm on cotton variety L 147 (Rainfed) it was concluded that 5 per cent injury level should be the basis for giving insecticidal treatment against bollworms.
2. The economic threshold level for bollworms on cotton variety AHH 468 was worked out to be 5 per cent and it was recommended that 5 per cent injury level of bollworms should be taken into consideration in protecting the cotton crop from bollworm attack.
3. It was recommended that the following plant protection packages should be adopted as eco- friendly and economical for effective integrated management of pests of hybrid cotton:
   a) Imidacloprid 70 WS seed treatment @ 10 gm / kg seed before sowing
   b) One spray of recommended systemic insecticide for sucking pests based on ETL if required
   c) Two releases of Trichogramma chilonis egg parasitoid @ 1.5 lakh per hectare at 45 to 50 and 55 to 60 days after sowing
   d) One spray of HaNPV @ 500 LE per hectare
   e) One spray of neem seed extract 5 %
   f) Need based one or two sprays of recommended insecticides for bollworms based on ET level
4. For effective, efficient and economical integrated pest management in rain fed cotton following revised IPM module was recommended:
   a) Thiomethoxam 70 WS seed treatment @ 4.28 gm/kg seed before sowing
   b) One spray of Acetamiprid 20 SP @ 15 g a.i. / ha for sucking pests based on ET level
   c) Two releases of Trichogramma chilonis egg parasitoid @ 1.5 lakh per hectare at 45 to 50 and 55 to 60 days after germination
   d) For bollworms ETL based one spray each of Azadirachtin 300 ppm @ 5 ml / L, Spinosad 45 SC @ 50 g. a.i. / ha and beta-cyfluthrin 2.5 EC @ 0.0025 %

D. In General Chemical Control:

1. Six sprayings of insecticide + fungicide (Endrin 0.02 % + Copper Oxychloride 50 WP @ 0.25 %) was found beneficial in protecting cotton crop from pests and diseases.
2. EC formulations were found superior to ULV formulations in reducing the bollworm damage and recording higher yield per hectare.

COTTON PATHOLOGY

A. Survey

Bacterial blight followed by grey mildew of cotton were found as major leaf spot diseases of hirsutum cotton. The arboreum group was least affected by bacterial blight but found highly susceptible to grey mildew. The alterneria and mirothecium leaf spot were observed as minor diseases.

B. Disease reaction

Dahiya disease caused by Ramularia gossypii (speg) cif. can affect G. arboreum, G. hirsutum, G. herbaceum, G. barbadense and wild diploid species of cotton showing variable reactions. The disease incidence was observed at 9th, 10th, 11th and 12th week growth stage with maximum at 9th week stage.

C. Host plant resistance

1. During Fusarium wilt screening in artificial epiphytotic conditions 24 different varieties / strains of Akola Centre, AKA 8808 was found moderately resistant. Susceptible reaction was shown by all except AKA 8401 and AKA 8307 where they were found moderately susceptible reaction.
2. While screening 30 promising varieties / hybrids / strains of arboreum and hirsutum group against grey mildew disease in artificial conditions, none was found disease free. Variety DHY 286 was shown moderately resistant reaction during 1991 – 94 screening period.
3. Among 345 hirsutum and 231 arboreum strains screened against bacterial blight none of the strain was found immune to disease.
4. The Israel hybrids screened viz. Eldad, HA 195, Omari, GAHB 202, HA 34 and N 431 were found highly susceptible to collar rot in rainfed conditions and highly susceptible to bacterial blight grown under rainfed as well as in irrigated conditions both.

D. Pathogen race identification

Race No. 10 of bacterial blight caused by Xanthomonas campestris pv malvacearum (now Xanthomonas oxanopodis pv malvacearum) was identified from various varieties / hybrids grown in Cotton Research Unit and at cultivators field.

E. Estimation of losses

Higher yield losses due to grey mildew disease were observed in AKH 4 in artificial inoculated conditions (63.17 %) and in natural conditions (47.54 %). The losses were noticed in PKV Hy 2 (19.64 %) and PKV Rajat (10.17 %) in artificially inoculated conditions. The losses were found negligible in these varieties / hybrids (03.07 % and 01.18 % respectively) in naturally infected conditions.

F. Crop management

1. The disease incidence and intensity of bacterial blight and grey mildew to 60 X 60 cm, 60 X 30 cm and 90 X 20 cm planting pattern used for PKV Rajat did not differ.
2. The differences in disease incidence and intensity of bacterial blight due to 60 X 60, 90 X 60 and 90 X 90 cm with 25:12.5:12.5, 50:25:25 and 75:37.5:37.5 NPK fertilizer dose for hybrids like PKV Hy 2, 3 and 4 were not found significantly even for interaction.

G. Chemical control

1. Dusting of 300 mesh Sulphur 20 kg / ha early in the morning or late in the afternoon for the control of grey mildew.
2. Foliar spray of 0.3 per cent Copper fungicide or Dithane Z-78 or Monocozeb 0.25 per cent for the control of alternaria blight.
3. Foliar spray of Streptocyclin 100 ppm + 0.25 per cent Copper Oxy-chloride for the control of bacterial blight or Foliar spray of Agrimycin – 100, 50 ppm in combination with 0.25 per cent Copper Oxy-chloride for the control of bacterial blight.
4. Seed treatment of 0.1 per cent Carboxine (Vitavax) + 0.3 per cent Thirum for the control of seed borne diseases.
5. Amongst the chemicals tested, foliar spraying of wettable sulphur was found most effective followed by folicur (750 ml / ha) and carbendazim to control the grey mildew with increase in yield.

H. Biological control

1. Foliar spray of bacterial culture No. 12 (Areomonas sp.) and culture No. 51 (Pseudomonas sp.) was found effective to reduce the disease incidence and intensity of bacterial blight next to Streptocycline + Copper Oxychloride as chemical treatment.
2. Foliar spray of 5 per cent neem leaves extract or 5 per cent neem seed extract should be used for the control of bacterial blight of cotton.
   

Bollworms like, spotted bollworm, Earias spp.; american bollworm, Helicoverpa armigera (Hubner) and pink bollworm, Pectinophora gossypiella (Saunders) known to be major pests of Cotton. Bollworm Larvae cause damage to the green fruiting bodies (Squares, flowers and bolls) by boring and feeding inside. These pests active throughout the season. Under unprotected condition bollworms can cause losses to the tune of 30-80 per cent in cotton production.

The lowest number of insect that cause economic injury is referred as Economic Injury Level (EIL). The EIL is enable us to identify the population level at which insect cause damage to a crop. Concept of EIL is developed to overcome the problems like insecticide resistance, pest resurgence, insecticide residues and non target effects caused by indiscriminate use of broad spectrum insecticides.

However, application of the chemical insecticides before causing economic injury (damage) to the crop is most important for effective management of pest and to achieve the expected yield. The population density at which control measures should be initiated against an increasing pest population to prevent economic damage and to suppress the pest population below EIL, is often referred as Economic Threshold Level (ETL). ETL is the best known and most widely used index in making pest management decisions.

Bollworms known to be the economically important pests of cotton crop which includes spotted bollworm, Earias spp.; american bollworm, Helicoverpa armigera (Hubner) and pink bollworm, Pectinophora gossypiella (Saunders). They damage to the green fruiting bodies (Squares, flowers and bolls) leads to shedding and thereby resulting in reduction in yield. Under unprotected condition the bollworms can cause damage to the tune of 80 per cent.

Chemical Pesticides plays an important role in pest management in Agriculture. This is the unique and simplest way of pest management rampently use by the farmers. Knowledge about chemical insecticides, their efficacy and doses for bollworm control is most important. Farmers often use chemical insecticides which are not recommended against cotton bollworms, therefore they could not get expected control which leads to increase in number of sprays with higher doses. Indiscriminate use of chemical pesticides by farmers resulted bad effects on environment, hence, their judicious use is essential for eco friendly pest management.