Bt cotton

Geography glossary

Topic: Major Crops of India: Distribution and Conditions · NCERT: Beyond NCERT

Meaning

Bt cotton is genetically modified (GM) cotton that carries a gene from the soil bacterium Bacillus thuringiensis (Bt). The gene makes a protein that is poisonous to bollworms, the caterpillars that bore into cotton bolls [1]. It is India's only commercially grown GM crop. It was introduced in 2002 and now covers over 90% of the cotton area, so it shapes the yields, costs and farm distress of the whole cotton economy.

Explanation

How it works (cause → process → result)

  • Cause: the bollworm problem
  • Bollworms are caterpillars that bore into the cotton boll (the seed case that holds the fibre).

  • They destroy the lint, so farmers had to spray insecticide again and again.

  • Process: borrowing a gene from a bacterium

  • Scientists took a gene from Bacillus thuringiensis, a bacterium found in soil.
  • They put this gene into the cotton plant. "Genetically modified" means the plant's genes were changed in a laboratory.

  • The gene makes the plant produce its own Bt protein. When a bollworm eats the plant, the protein poisons it [1].

  • Result: the early gains of the 2000s

  • Fewer bollworm attacks
  • Fewer insecticide sprays
  • Higher yields and farm incomes [1]

Approval and spread

  • Approval: Bt cotton was cleared by the GEAC (Genetic Engineering Appraisal Committee), the body that approves GM crops. It was introduced commercially in 2002 [1].
  • Spread: it now covers over 90% of India's cotton area.
  • Species: India grows all four cultivated cotton species. All Bt cotton hybrids belong to Gossypium hirsutum (American upland cotton). This species also gives nearly 90% of India's hybrid cotton [1].
  • Bt cotton is therefore not desi cotton (G. arboreum, G. herbaceum). A hybrid is seed made by crossing two parent lines.

The plateau: why the gains stopped

  • Pink bollworm resistance (from about the 2010s)
  • The pink bollworm developed resistance to Bt toxins. This means the pest was no longer killed by the Bt protein.

  • Pest damage returned, and yields stopped rising.

  • Illegal HTBt seed

  • Herbicide-tolerant Bt (HTBt) is GM seed that survives weed-killer sprays.

  • It is not approved, but it is still sold illegally.

  • High seed prices: farmers have to buy fresh hybrid seed every season, which raises costs.

  • Agrarian distress in Vidarbha: high costs and erratic rain push farmers into debt.

Conditions it still depends on

  • Bt only protects against pests. The plant still needs the normal conditions for cotton:
  • Kharif crop, sown with the south-west monsoon in June–July
  • Drier black cotton soil (regur) of the Deccan, which holds moisture through dry spells
  • High temperature, 210 frost-free days, and bright sunshine at flowering

  • 6–8 months to mature

  • About 62% of India's cotton is rainfed [1]. Because of this, a Bt crop can still fail when the monsoon fails.

Where it occurs

  • All of India's cotton belt: Bt cotton covers over 90% of the cotton area. India has the world's largest cotton area, at 114.84 lakh ha (2024-25) [1].
  • Official cotton zones [1]:
  • Northern Zone (Punjab, Haryana, Rajasthan): irrigated by canals, so yields are high.
  • Central Zone (Gujarat, Maharashtra, Madhya Pradesh): mostly rainfed. Yields are very low in Vidarbha (Maharashtra).
  • Southern Zone (Telangana, Andhra Pradesh, Karnataka): mixed irrigation, medium yields.

  • Odisha and Tamil Nadu also grow cotton [1].

  • Leading producers: Gujarat, Maharashtra and Telangana.

  • Vidarbha (Maharashtra): the main hotspot of Bt-era farm distress, where rainfed cotton meets high seed costs.
  • Regulator: the GEAC approves GM crops. It approved Bt cotton in 2002 [1]. HTBt has no such approval.

Don't confuse with

  • HTBt (herbicide-tolerant Bt) cotton: Bt cotton only resists bollworms and is approved. HTBt also survives weed-killer sprays and is not approved in India.
  • Desi cotton (G. arboreum, G. herbaceum)*: these are the Asian species. All Bt hybrids are G. hirsutum*** (American upland cotton) [1].
  • High-Density Planting System (HDPS): this is a planting method (more plants per hectare), not a GM technology. Field trials raised yields by about 40%, and early harvest cut pink bollworm losses [1].
  • Narma: this is the name for long-staple American cotton grown in the north-west. It is a fibre-length type, not a GM trait.

Prelims Hooks

  • Bt gene source: Bacillus thuringiensis, a soil bacterium. It is not a virus and not a fungus.
  • Introduced commercially in 2002 after GEAC approval [1]. It now covers over 90% of the cotton area.
  • All Bt cotton hybrids in India are Gossypium hirsutum [1]. Trap: "Bt cotton is a desi variety" is wrong.
  • The pink bollworm has developed resistance to Bt toxins, which is why yields have plateaued.
  • HTBt is not approved in India. Trap: "HTBt is a GEAC-approved variety" is wrong.
  • HDPS is the government's response to falling yields: about 40% higher yields in trials, and fewer pink bollworm losses through early harvest [1].

Mains Points

  • Bt cotton is a technology with a time limit (GS-III, agriculture and biotechnology):
  • Yields, incomes and pest control improved quickly after 2002 [1].
  • Pink bollworm resistance, illegal HTBt seed and high seed prices then stopped the gains.

  • Policy needs: refuge planting (strips of non-Bt cotton around a Bt field, so the pest does not become resistant as fast), short-duration varieties, regulated GM approvals through GEAC, and integrated pest management.

  • The seed alone cannot fix a water problem (GS-I distribution, GS-III agriculture):

  • About 62% of cotton is rainfed [1]. The irrigated north-west gets high yields, but rainfed Vidarbha gets very low yields.

  • Costly hybrid seed combined with failed monsoons leads to debt and agrarian distress in Vidarbha.

  • Policy responses after the plateau:

  • HDPS raised yields by about 40% in trials and cut pink bollworm losses [1].
  • The Mission for Cotton Productivity (2025-26, five years, ₹5,659.22 crore) promotes climate-resilient, pest-resistant varieties and ELS cotton. It targets 498 lakh bales by 2031 [1].
  • MSP buying through CCI gives farmers a price floor.

Related concepts

Read more

Sources

  1. 1"White Gold: India's Cotton Story — From Seed to Shirt" (PIB, 20 July 2026)static.pib.gov.in · tier 1