Pink bollworm affects Bt cotton

  • Disheartening stories of Bt cotton farmers are unfolding across Raichur district, which is one of the major cotton growing districts in the State.

  • The extent of loss is yet to be measured as no survey has been conducted. Cotton is cultivated on nearly 60,000 hectares of lands in the district, most of which is Bt cotton.
  • Farmers started switching to the crop in big numbers in 2007-08 and there has been increase in acreage over the years since then.

Bt cotton

  • Bt cotton is genetically engineered with a gene from the bacteria Bacillus thuringiensis (Bt) and is toxic to the bollworm, a pest that preys on the cotton plant. There’s also the possibility that the plant is being attacked by other insects.
  • A team of agricultural scientists from the University of Agricultural Sciences, Raichur (UAS-R) will be visiting some of the affected fields to study the pest menace.
  • The pink bollworm, with its negligible population, was not a threat to cotton crop when the Bt technology was developed. But over a period of time, the worm massively increased its population and is now causing maximum damage to the crop
  • Bt cotton is vulnerable to climatic variations and attack by sucking pests and insects outside the resistance-claim purview. Farmers control sucking pests, usually found at the backside of leaf, by heavily spraying different pesticides.
  • But we cannot control pink bollworm through pesticide spraying as it is inside the cotton boll. The cotton bolls look absolutely normal from outside. But, each boll is infected by the pink bollworm inside. The worm eats cotton seeds and thus prevents the development of cotton staple fibre around it well before the cotton boll opens