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COTTON — हिन्दी
Bollworm Control
Planning Instructions for Bollgard II & Bollworm Management
Bollgard II coon hybrids produce two Bt proteins, Cry1Ac and Cry2Ab, which together manage the key lepidopteran pests of coon viz., American bollworm, Spoed bollworm, Pink
bollworm and the Tobacco caterpillar. As per the Gazee noficaon S.O.4215 (E) dated December 27, 2016 by Ministry of Agriculture and Farmer’s Welfare, Department of
Agriculture, Cooperaon and Farmer’s Welfare, Government of India, the seeds in this packet are mixed with 5% Non-Bt refugia. This technology does not provide control of sucking insect pests of cotton.
Refugia-in-Bag (RIB) Concept for Insect Resistance Management
Blending 5% of Non-Bt seeds in Bt cotton seed pouch is called the Refugia-in-Bag (RIB)
concept. Non-Bt hybrids possess similar duration and fiber properties as Bt hybrids. Minimal
yield loss is expected due to mixing of Non-Bt seeds; however, RIB helps delay insect resistance
to Bt and enhances the durability of the technology.
The following general guidelines can help to get maximum benefits from Bollgard II cultivation:
- Land Preparation : Remove and burn debris of the previous crop for field sanitation. Give two deep summer ploughings to reduce soil-borne diseases, insects and weeds. Prepare the field by repeated harrowing to bring the soil to suitable tilth.
- Manures and Fertilizers : Apply 5–6 tonnes of farmyard manure 3–4 weeks before sowing.
- Fertilizers : Apply fertilizers as per the soil test report and local recommended practices.
- Spacing : Adopt spacing requirements as per local recommendations.
- Light / Sandy / Shallow Soils : 75 × 60 cm or 90 × 60 cm
- Medium Black Soils (Medium Depth): 90 × 60 cm or 100 × 60 cm
- Deep Black Cotton Soils (Vertisols) : 120 × 60 cm or 120 × 75 cm
- Sowing Method : Plant 2 seeds per hill for maintaining proper population. After germination, retain one vigorous plant per hill and remove the weaker one.
- Gap Filling : To achieve optimum plant stand, perform gap filling within a week if necessary.
- Inter-Cultivation and Weed Control : Follow need-based hand weeding and inter-cultivation practices to control weeds, improve aeration, and conserve soil moisture. Follow recommended herbicide application, if practiced locally.
- Irrigation: Ensure moisture during critical growth stages — germination, seedling growth, flowering, and boll formation. Avoid water stagnation, as cotton is susceptible to prolonged waterlogging.
Integrated Pest Management (IPM)
The following integrated practices are recommended:
- Follow summer ploughing and field sanitation as mentioned earlier.
- Seed Treatment: BG II cotton seeds are pre-treated for controlling sucking pests.
- Sucking Pest Control: If infestation crosses the Economic Threshold Level (ETL) at any crop stage, spray recommended insecticides.
Pets
- Jassids
- Whiteflies
- Aphids
- Thrips
- Mites
Economic Threshold Level (ETL)
- 1–2 nymphs or adults per leaf
- 8–10 nymphs or adults per leaf
- 10% plants infested
- 10 nymphs or adults per leaf Mites
- 10 adults or 20 nymphs per leaf
Bollworm Control
Supplementary insecticide sprays may be needed to manage bollworms if their population reaches or exceeds ETL. To know if bollworms have reached ETL, scout Bollgard II fields weekly as follows:
- American Bollworm (ABW): Randomly select 20 Bollgard II plants per acre. ETL is reached if 2 or more ABW larvae are found in 20 plants, or if 10% of total bolls are damaged by ABW.
- Pink Bollworm (PBW): Randomly select 20 flowers or mature bolls per acre. ETL is reached if 2 or more PBW larvae are found in 20 flowers or bolls. alternatively, ETL is reached if pheromone traps (3 traps/acre) record an average of 8 PBW moths per trap per night for three successive nights.
Follow insecticide recommendations from your local Agricultural University or Department of Agriculture.
Note: For non-target insects like Spodoptera and Stem Weevil, follow local recommended practices.
Additional IPM Practices
- Use trap/barrier crops, pheromone or light traps, bird perches, natural enemies, and bio-rational insecticides (HaNPV, Neem).
- Avoid repeated use of the same class of insecticides.
- Timely Crop Termination: Avoid rejuvenation (re-flushing) of Bollgard II crop in areas with high PBW incidence.
- Field Sanitation: Remove unopened or damaged bolls and bury them in deep pits.
- Deep Ploughing: After harvest, deep plough to expose and kill pupae and diapausing PBW larvae.
Management of Common Diseases in Cotton
Follow need-based recommended practices for controlling diseases such as Alternaria leaf spot, Grey mildew, Leaf blight, and Boll rot. Common diseases include:
- Alternaria Leaf Blight (Alternaria macrospora): Small pale brown circular spots with concentric ridges (target board appearance).
- Cercospora Leaf Spot (Cercospora gossypina): Reddish dots expanding into white/light brown spots with red margins.
- Grey Mildew (Ramularia areola): Yellowish-green angular spots turning brown with whitish fungal growth below leaves.
- Bacterial Blight (Xanthomonas campestris pv. malvacearum): Angular spots, vein blight, black arm on stems, and boll blight.
Disease Management
- Maintain adequate nutrition and proper water management.
- Encourage sufficient FYM application.
- Adopt wider spacing or paired-row planting to reduce canopy humidity.
- Remove and destroy infected leaves to minimize spread.
- Spray Copper oxychloride or Wettable sulfur (2–2.5 g) + Bavistin (1–1.5 g)/L for fungal spots.
- For bacterial blight: Copper oxychloride (2–2.5 g) + Streptocycline (0.1 g)/L.
- For combined fungal and bacterial infections: Copper oxychloride (2–2.5 g) + Bavistin (1–1.5 g) + Streptocycline (0.1 g)/L.
- Repeat sprays 2–3 times at 15–20 day intervals after symptom appearance.
Management Strategies for Wilt in Cotton
Wilt is severe in light to medium soils under water stress. Major pathogens include Fusarium oxysporum, Rhizoctonia solani, and Rhizoctonia bataticola.
Symptoms
Wilting during flowering to boll setting, dull plants, yellow leaves, vascular discoloration, and root rot. In waterlogged conditions, wilt may appear suddenly—drain water immediately and drench with systemic fungicides.
Management
- Timely irrigation, especially in light soils.
- Avoid fields with a history of wilt.
- Apply adequate FYM.
- Spray Nitrophoska-Foliar @ 3 g/L at vegetative stage and Nitrophoska-Foliar @ 3 g/L + Planofix @ 0.3 ml/L at flowering.
- Soil drench with Bavistin (Carbendazim) + Contaf (Hexaconazole) or Sheathmar (Validamycin) @ 3 g/L (0.5–1 L/plant) at 50–60 DAS.
Harvesting
Harvest Bollgard II cotton as per normal harvesting practices.
Disclaimer
The guidelines in this leaflet are compiled from various sources. Soil type, adverse climatic conditions, poor management, or pest and disease attack may reduce yield. Farmers are responsible for production outcomes. For best results, follow proper sowing and crop management practices. The company is not liable for crop failure despite following these guidelines.
Stewardship Guidance
The performance of Bollgard II cotton technology depends on adherence to official product usage guidelines recommended by Central and/or State Agricultural Institutes. Non-adherence can lead to suboptimal results. High bollworm incidence, including PBW resistance, may require ETL-based pest management. The licensor of this technology is not liable for any performance issues arising from failure to follow guidelines or from germplasm-related factors.