What is Bt Cotton?

Bt cotton is a genetically modified (GM) variety of cotton that contains a gene from the soil bacterium Bacillus thuringiensis (Bt). This gene produces Cry proteins (Cry1Ac and Cry2Ab) that are toxic to specific lepidopteran pests, particularly the American bollworm (Helicoverpa armigera), which was the most devastating cotton pest in India. Bt cotton is the only GM crop approved for commercial cultivation in India.

The Genetic Engineering Appraisal Committee (GEAC) under the Ministry of Environment, Forest and Climate Change approved Bt cotton for commercial cultivation in March 2002, making it India's first and so far only authorised transgenic crop. The technology was initially developed by Monsanto (now Bayer) through its Indian subsidiary Mahyco-Monsanto Biotech (MMB).

Since its introduction, Bt cotton has transformed India from a net importer to the world's largest cotton producer, with adoption rates exceeding 95% of total cotton area. However, challenges such as pink bollworm resistance to Bt toxins and the controversy over illegal HTBt (Herbicide-Tolerant Bt) cotton cultivation continue to shape policy debate.

How Bt Cotton Works

The Bt gene inserted into cotton produces crystalline (Cry) proteins inside the plant's tissues. When the bollworm larva feeds on the plant, these Cry proteins bind to specific receptors in the insect's gut lining, creating pores that cause the gut to leak, leading to septicaemia and death of the larva. The Cry proteins are highly specific — they only affect lepidopteran pests and are non-toxic to humans, livestock, and beneficial insects like honeybees.

Bollgard I (first generation) contained the Cry1Ac gene, effective against the American bollworm. Bollgard II (second generation, approved 2006) stacked Cry1Ac + Cry2Ab genes, providing dual-mode protection and delaying pest resistance. The refuge strategy requires farmers to plant 20% of their cotton area with non-Bt varieties, ensuring a population of susceptible insects to dilute resistance development.

Key Features

# Feature Details
1 Gene Source Bacillus thuringiensis (soil bacterium)
2 Proteins Produced Cry1Ac (Bollgard I), Cry1Ac + Cry2Ab (Bollgard II)
3 Target Pest American bollworm (Helicoverpa armigera)
4 Approval Year 2002 (by GEAC)
5 Regulator GEAC under MoEFCC
6 Adoption Rate Over 95% of India's cotton area
7 Key Challenge Pink bollworm resistance to Cry proteins (reported since mid-2010s)

Current Status / Latest Data

  • Cultivation area (2025-26): Estimated at 11.2 million hectares, producing approximately 23.8 million 480-lb bales.
  • Adoption: Over 95% of India's cotton area uses Bt cotton varieties.
  • Pink bollworm resistance: Confirmed in several states including Gujarat, Maharashtra, and Andhra Pradesh. Scientists recommend refuge planting (non-Bt cotton on 20% area) to delay resistance.
  • HTBt cotton controversy: Herbicide-Tolerant Bt cotton (containing CP4-EPSPS gene for glyphosate tolerance) is not approved by GEAC but is widely cultivated illegally due to perceived weed management benefits. In 2025, an expert panel submitted a favourable biosafety report on HTBt cotton, bringing it closer to potential approval.
  • Status as sole GM crop: Despite demand, no other GM food crop (GM mustard, Bt brinjal) has received final commercial approval.
  • India remains the world's largest cotton producer and second-largest exporter.

UPSC Exam Corner

Prelims: Key Facts

  • Bt cotton: only GM crop commercially approved in India (since 2002)
  • Gene: from Bacillus thuringiensis; produces Cry proteins toxic to bollworm
  • Regulator: GEAC (under MoEFCC) — renamed from "Genetic Engineering Approval Committee" to "Appraisal" Committee in 2010
  • Bollgard I: Cry1Ac; Bollgard II: Cry1Ac + Cry2Ab
  • HTBt cotton: not approved but illegally widespread
  • India's cotton area: ~11 million hectares; adoption rate >95%
  • Bollgard II approved: 2006 (dual-gene stack for resistance management)
  • Refuge strategy: plant 20% area with non-Bt cotton to delay pest resistance
  • Pink bollworm: developed resistance to Cry proteins in Gujarat, Maharashtra, AP
  • Cry proteins: toxic to lepidopteran pests only; safe for humans, livestock, bees
  • India: world's largest cotton producer and second-largest exporter

Mains: Probable Themes

  1. "Evaluate the impact of Bt cotton on Indian agriculture — gains, losses, and the way forward."
  2. "Discuss the regulatory and ethical challenges in approving GM crops in India." — GEAC process, Supreme Court moratorium, public opposition
  3. "Pink bollworm resistance to Bt cotton highlights the limits of single-gene solutions. Examine."
  4. "The illegal spread of HTBt cotton exposes gaps in India's biosafety regulatory framework. Analyse."
  5. "Compare the socio-economic outcomes of Bt cotton adoption in India with other GM-adopting countries."
  6. "Examine the role of technology fees and intellectual property in Bt cotton adoption." — Monsanto/Bayer royalty dispute, seed pricing, farmer access

Key Comparison: Bollgard I vs Bollgard II

  • Bollgard I (Cry1Ac only): introduced 2002; single-gene protection; resistance emerged faster
  • Bollgard II (Cry1Ac + Cry2Ab): introduced 2006; dual-gene stack; better resistance management but pink bollworm still developed resistance by mid-2010s

Sources: GEAC — MoEFCC | ISAAA — Bt Cotton India | USDA — India Cotton Report 2025 | Insights on India — HTBt Cotton 2025