Illegal Bt cotton covers 30% area, fuels ₹1,500-cr black market. Unauthorised Herbicide-Tolerant Bt cotton has spread across an estimated 65-72 lakh acres in India, fuelling an estimated ₹1,500-crore black market for seeds, according to a study backed by Federation of Seed Industry of India. This accounts for nearly one-third of India's cotton area. The study is titled 'Unauthorized Cultivation of HTBt Cotton in India: Extent, Drivers & Implications'.