Although the GM variety, officially allowed in 2002, sharply raised yields initially, productivity is now projected to decline amid signs of diminishing returns, according to a flagship paper presented by KR Kranthi, the director of the Central Cotton Research Institute, India’s ”Bt referral lab”.

New pests have emerged, repeated farming of Bt varieties has ravaged soils and farmers have been unable to pick the right variety from among 780 Bt hybrids, Kranthi’s points out. ”Currently the main issue... is stagnation of productivity at an average of 500 kg lint per hectare over the past seven years,” Kranthi has stated. Yields have simply leveled off, despite India’s Bt cotton acreage expanding from 5.6% in 2004 to 85% in 2010.