A new field study estimates that unauthorised cotton was cultivated on 65-72 lakh acres during the 2025-26 kharif season, accounting for 24-30% of India’s total cotton acreage. farmers appear to be adopting it at scale While India has not approved herbicide-tolerant Bt (HTBt) cotton.
The study says the spread is being driven by labour shortages and the high cost of manual weeding.
It combined farmer surveys, supply-chain assessments and laboratory testing of cotton samples. HTBt cotton is Bt cotton with an added herbicide-tolerance trait, allowing farmers to use glyphosate for weed control. The spread of HTBt comes as India struggles with declining cotton production. The government has attributed the decline to several factors, including lower acreage, uneven rainfall, extreme temperatures, pests and diseases, and farmers shifting to more remunerative crops. Glyphosate is a broad-spectrum herbicide used to control weeds.
The study, conducted by the South Asia Biotechnology Centre (SABC) with support from the Federation of Seed Industry of India (FSII) and National Seed Association of India (NSAI), covered 16 cotton-growing districts across Maharashtra, Telangana, Andhra Pradesh and Rajasthan. The study found that weed control using glyphosate costs ₹ 750-850 an acre, compared with ₹ 12,000-15,000 for manual weeding. Cotton output fell from 35.2 million bales in 2020-21 to an estimated 29.1 million bales in 2025-26, a decline of about 17.5%, according to government data. Productivity also fell from 451 kg per hectare to 431 kg per hectare over the period. It has now approved a ₹ 5,659-crore Mission for Cotton Productivity to address these constraints. Maharashtra has the highest adoption, at 58%, according to the study. Adoption is also high in Telangana and Andhra Pradesh at 66% and 49%, respectively. The study estimates that the informal HTBt seed market is worth ₹ 820-880 crore. It also found that sales of legal Bollgard-II seed fell 22.3% nationally between 2022 and 2026. As per the study, its use rose 26% from 27,721 kilolitres in 2024-25 to 35,642 kilolitres in 2025-26. It also found that glyphosate is increasingly being sold through underground networks in bulk quantities of up to 20-litre drums.
