Meaning
Bt cotton is a genetically modified cotton variety developed to protect the cotton crop from bollworm attacks.
The name Bt comes from Bacillus thuringiensis, a soil bacterium that produces proteins toxic to certain insect pests. Scientists transferred specific Bt genes into cotton plants so that the plant itself could produce insecticidal proteins against bollworms.
In simple terms, Bt cotton is cotton that has been genetically engineered to resist major bollworm pests.
It was approved for commercial cultivation in India in 2002 and remains India’s only genetically modified crop approved for commercial cultivation.
How It Works
Bt cotton contains genes that produce Cry proteins. These proteins are toxic to specific bollworm larvae when they feed on the cotton plant.
The main target pests include:
• American bollworm
• Pink bollworm
• Spotted bollworm
• Spiny bollworm
When bollworm larvae eat Bt cotton tissues, the Bt protein affects their gut and kills them. This reduces crop damage and can reduce the need for chemical insecticide sprays against bollworms.
However, Bt cotton does not protect the crop from all pests. It is mainly effective against bollworms. Other pests like whitefly, aphids, jassids and mealybugs may still require management.
Bt Cotton in India
Bt cotton was introduced in India in 2002. In the initial years, it helped reduce bollworm damage and pesticide use in many cotton-growing regions. It also contributed to higher adoption of hybrid cotton seeds and expansion of cotton cultivation.
Over time, Bt cotton spread rapidly across India’s cotton belt. By the mid-2010s, it covered most of India’s cotton area.
The major cotton-growing states include:
• Gujarat
• Maharashtra
• Telangana
• Andhra Pradesh
• Madhya Pradesh
• Rajasthan
• Haryana
• Punjab
• Karnataka
• Tamil Nadu
Bt cotton became important because cotton is a major Kharif cash crop and supports farmers, ginning units, spinning mills, textile industries and exports.
Benefits
Bt cotton initially gave major benefits by controlling bollworm attacks. Bollworms were one of the most damaging pests in cotton cultivation, and their control required repeated pesticide spraying.
Major benefits included:
• Reduced bollworm damage
• Lower use of some insecticides
• Better crop protection
• Higher yield in many regions during initial years
• Lower crop losses from bollworms
• Support to cotton productivity and farmer income
Bt cotton also reduced the immediate pressure of bollworm infestation in many areas. In the early phase, it was seen as a major success of agricultural biotechnology in India.
Concerns
The biggest concern today is that Bt cotton is no longer as effective as it was in the initial years.
The most serious issue is pink bollworm resistance. Pink bollworm has developed resistance to available Bt cotton technologies in several regions. Scientific studies and policy discussions have noted that Bt cotton’s initial success during 2002–2013 weakened as pink bollworm resistance emerged later.
This has contributed to lower yields and higher pest-management costs in many cotton-growing areas.
Other concerns include:
• Pink bollworm resistance
• Rising pesticide use for secondary pests
• Dependence on costly hybrid seeds
• Weak refugia compliance
• Monocropping of cotton
• Illegal herbicide-tolerant cotton seeds
• Declining soil health in cotton belts
• Climate stress and rainfed cultivation
• High input cost for farmers
India’s cotton production has also faced pressure from declining GM cotton effectiveness, pest attacks and climate-related stresses. Cotton output reportedly dropped to a 15-year low of around 25 million bales, reflecting deeper problems in the cotton sector.
Refugia and Resistance
Resistance develops when pests are continuously exposed to the same Bt protein over many crop cycles. The insects that survive pass on resistance to the next generation.
To slow this process, farmers are advised to plant refuge crops, meaning a small area of non-Bt cotton near Bt cotton fields. These non-Bt plants allow susceptible insects to survive and mate with resistant insects, delaying resistance development.
But in many areas, refugia compliance has been weak. This has accelerated resistance in pests like pink bollworm.
Resistance management requires:
• Proper refugia planting
• Crop rotation
• Integrated Pest Management
• Monitoring of pest populations
• Avoiding continuous monocropping
• Timely destruction of crop residues
• Use of pheromone traps
• Better farmer awareness
This shows that Bt cotton cannot work as a standalone solution. It must be part of a broader pest-management strategy.
Relevance for India
Bt cotton is important for India because cotton is linked with agriculture, textiles, exports and rural employment.
India has the world’s largest cotton acreage, but productivity remains low compared to many countries. Bt cotton helped in the initial phase, but current challenges show that long-term productivity needs more than genetic modification.
India needs a balanced cotton strategy focusing on:
• New pest-resistant varieties after proper biosafety checks
• Integrated Pest Management
• High-Density Planting System
• Better seed regulation
• Climate-resilient cotton varieties
• Improved irrigation and soil health
• Strong extension services
• Farmer training on refugia
• Control of illegal seed markets
• Better procurement and price support
Important factual points to remember:
• Bt cotton contains genes from Bacillus thuringiensis
• It produces Cry proteins toxic to bollworms
• It was approved in India in 2002
• Bt cotton is India’s only commercially approved GM crop
• It was first approved by the Genetic Engineering Appraisal Committee
• Bt cotton mainly targets bollworms, not all cotton pests
• Pink bollworm resistance is now a major concern
• Refugia are used to delay pest resistance
• Illegal herbicide-tolerant cotton is not approved for commercial cultivation in India
• Bt cotton must be combined with Integrated Pest Management
Conclusion
Bt cotton initially helped India control bollworms and improve cotton cultivation. But pink bollworm resistance, weak refugia use, secondary pests and climate stress show that biotechnology alone cannot sustain cotton productivity. India needs Bt cotton to be supported by strong pest management, seed regulation and climate-resilient farming.
