Context

• Cotton is one of the most important commercial crops cultivated in India and accounts for around 25% of the total global cotton production.
• However, recent data suggests that both production and yields are falling and it is a reason to worry.

The Cotton Crop

• Cotton, like coconut, is a source of all the three Fs: Food, Feed and Fibre.
• Cotton crops are soft, fluffy stable fibre that is used extensively in the textile industry.
• Cotton is one of the most important cash crops in India and it plays a crucial role in the industrial and agricultural economy.
• Cotton in India provides direct livelihood to 6 million farmers and indirectly employs about 40-50 million people in its allied processes such as trade and processing.

Production and Consumption of Cotton in India

• Production
  • The white fluffy fibre or lint constitutes only about 36% of kapas, the raw un-ginned cotton harvested by farmers.
  • The rest is [seed (62%) and wastes (2%)] separated from the lint during ginning. Cotton seed, in turn, contains 13% oil used for cooking and frying.
  • The 85% residual cake, after extraction of oil from the seed and 2% processing losses, is a protein-rich feed ingredient for livestock and poultry.
• Consumption
  • Cotton has a roughly two-thirds share in India’s total textile fibre consumption.
  • Cottonseed which is not so well known is the country’s third largest domestically-produced vegetable oil (after mustard and soyabean) and its second biggest feed cake/meal (after soyabean).

The Revolution of Bt Cotton

• The Bt cotton variety is genetically transformed with the Bt gene to protect the plants from bollworm, a major pest of cotton.
• From 2002, Indian farmers began planting genetically-modified (GM) cotton hybrids incorporating genes isolated from a soil bacterium Bacillus thuringiensisor Bt.
• Between 2000-01 and 2013-14, India’s cotton production, in terms of lint, almost trebled from 140 lakh to 398 lakh bales of 170 kg each.
• So did the output of oil and cake to nearly 1.5 million tonnes (mt) and 4.5 mt respectively.
• 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 did not last and the data shows both production and yields falling in recent years.

 Reason Behind Falling Crop Yield

• Pink Bollworm (PBW): A Different Ballworm
  • The reason for that had primarily to do with the Pectinophora gossypiella or pink bollworm (PBW).
  • The Bt toxins were originally supposed to provide protection against both the Helicoverpa and PBW caterpillars that burrow into the bolls or fruits of the cotton plant in which the lint and seeds grow.
  • Bt cotton has retained its effectiveness against the American bollworm. But in 2014 an unusual bollworm has been detected.
• Unusually Large Survival of PBW Larvae
  • In 2014, an unusually large survival of PBW larvae was detected on cotton flowers at 60-70 days after sowing in Gujarat.
  • In the 2015 season PBW survivals were reported from Andhra Pradesh, Telangana, and Maharashtra too.
  • In 2021, even Punjab, Haryana and northern Rajasthan saw heavy infestation of the pest for the first time.
• Spreading Infestation of PBW
  • PBW was not a serious pest previously. It typically appeared in the crop’s later stages after the first picking, while confined to central and southern India.
  • But now, the infestation starts as early as 40-45 days after sowing at the initiation of flowering.
• Monophagous Nature of PBW
  • PBW is a monophagous pest that feeds mainly on cotton.
  • This is unlike Helicoverpa that is polyphagous, with alternative hosts from arhar (pigeon pea), jowar (sorghum) and maize to tomato, chana (chickpea) and lobiya (cowpea).
  • Being monophagous enabled the PBW larvae to develop resistance to Bt proteins over time.
  • As farmers virtually stopped growing non-Bt cotton. The PBW population that became resistant from continuously feeding on Bt hybrids gradually overtook and replaced the ones that were susceptible. 

Efforts at Controlling the Pests

• Conventional Method of Spraying Insecticide
  • The conventional route of spraying insecticides has had limited efficacy against the PBW larvae.
  • These feed on the cotton bolls as well as the squares (buds) and tender flowers, affecting lint quality and yields.
• Mating Disruption Method
  • It involves deploying Gossyplure, a pheromone signalling chemical that is secreted by female PBW moths to attract male adults.
  • In this case, the pheromone is artificially synthesised and filled into pipes or lures.
  • The Central Insecticides Board & Registration Committee under the Agriculture Ministry has approved the Project Bandhan, which is an exemplary initiative to promote pheromone-based IPM production system of cotton.
    • Under this,two mating disruption products PBKnot and SPLAT for controlling PBW, were approved.
    • The novel PB Knot pheromone technology is easy to use, affordable and environment friendly innovation to manage the PBW.
    • SPLAT-PBW is a flowable emulsion formulation technology for delivering Gossyplure.

Methodology of Mating Disruption Products and Their Outcome

• Methodology
  • PBKnot is a dispenser having a 20-cm hollow polyethylene pipe, into which 140-160 mg of Gossyplure is impregnated.
  • Each such “rope” that is tied to a cotton plant can release the pheromone over a 25 square-metre area. It translates into roughly 165 PBKnot-tagged plants every acre.
  • The ideal time to tag is 40-45 days after sowing just when flowering commences.
  • The pheromone gets released from the dispenser’s nano-size pores over 90 days, by which time the farmer would have harvested two pickings and the scope for infestation is minimal.
• Outcome
  • The South Asia Biotechnology Centre (SABC) has been conducting field experiments of PBKnot technology.
  • During the last three seasons from 2021, the experiments have demonstrated a reduction in PBW mating by up to 90%, resulting in 25% higher kapas

The Road Ahead: Incorporation of New Technologies

• While Bt technology gave a huge push to production during the first decade-and-a-half of this century, the yield gains from it have been somewhat eroded by the emergence of new dominant pests, especially PBW.
• The threat of pest infestation has also discouraged farmers in states like Punjab from growing cotton.
• It only highlights the central role that new technologies whether GM, next-generation insecticides or mating disruption will have to play in sustaining the cultivation of this fibre, food, and feed crop. 

Conclusion

• Cotton is the most important fibre crop produced in India because of the variety of its applications in all fields.
• The falling production is a cause of worry for many reasons especially the textile industry and, therefore, needs urgent attention of the government.