Context: This article is based on an Editorial “Why India’s cotton production decline is concerning” from the Indian Express. It explores pink bollworm damage to fiber plants and the promising technology-based mating disruption methods for pest control.

Cotton: The Versatile Crop Providing Food, Feed, and Fiber:

• Cotton is the Source of all the three Fs: Food, Feed and Fiber.
  • Food: Its seed contains 13% oil used for cooking and frying. Third largest domestically-produced vegetable oil.
  • Feed: The 85% residual cake of cotton, after extraction of oil from the seed and 2% processing losses, is a protein-rich feed ingredient for livestock and poultry.
  • Fiber: It has a roughly two-thirds share of India’s total textile fiber consumption. 

GM Cotton in India: A Decade of Success and Challenges:

• GM Crops in India: From 2002, Indian farmers began planting Genetically Modified (GM) cotton hybrids incorporating genes isolated from a soil bacterium Bacillus thuringiensis or Bt. 
• GM Cotton Component: The Bt genes coded for proteins toxic to the deadly American bollworm insect pest. 
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• Remarkable Yield Growth with Bt Cotton: As the share of Bt hybrids in the country’s area sown under cotton touched 95%, average per-hectare lint yields more than doubled from 278 kg in 2000-01 to 566 kg in 2013-14.
  • However, the gains didn’t last. Both production and yields fell after 2013-14, to 343.5 lakh bales and 447 kg/hectare in 2022-23.

Cotton Pest Challenge: The Rapid Evolution of Pink Bollworm Resistance:

• Earlier Scenario: PBW wasn’t a serious pest previously for Cotton production. It typically appeared in the crop’s later stages after the first picking, while confined to central and southern India. 
• Present Scenario: The infestation starts as early as 40-45 days after sowing at the initiation of flowering of cotton plants.
• Monophagous Nature – A Challenge for Bt Resistance: PBW is a monophagous pest that feeds mainly on cotton. Being monophagous enabled the PBW larvae to develop resistance to Bt proteins over time. 
  • The pest’s short life cycle, conducive for it to complete at least 3-4 generations in a single crop season of 180-270 days, further accelerated the resistance breakdown process.
  • Conventional insecticides have had limited efficacy against PBW larvae and affecting lint quality and yields.

A Way Forward: Transforming Cotton Pest Control with Innovation:

• Cotton Protection through Mating Disruption Technology : It involves deploying Gossyplure, a pheromone signaling chemical that is secreted by female PBW moths to attract male adults to cotton plants
  • Here, the pheromone is artificially synthesized and filled into pipes or lures and the male adult moths are, then, attracted towards the lures and do not mate with females during their 7-10 days time. 
  • In the event, eggs aren’t laid and they don’t grow into larvae, before pupating and becoming next-generation adults.
• Cotton Pest Management – Mating Disruption Products: 
  • PBKnot technology: It has demonstrated a reduction in PBW mating by up to 90%, resulting in 25% higher Cotton yields.
  • SPLAT-PBW: A flowable emulsion formulation technology for delivering Gossyplure is also gaining prominence in cotton production.

Conclusion:

• India’s declining cotton production is a pressing concern due to the threat of the pink bollworm. While GM cotton initially brought success, resistance in the pest led to a decline. Technology such as mating disruption provides a path toward restoring cotton yield.

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