here’s ugly fact #1: Most of the yield increase happened between 2002-5 when Bt comprised between 0.4-5.6% of India’s cotton. Obviously Bt couldn’t have accounted for more than a tiny speck of the national rise. [...] here comes ugly fact #2 - in the last 4 years, as Bt has risen from 67% to 92% of India’s cotton, yields have dropped steadily. [...] Then the ugly fact #3: since 2007, yields in Andhra Pradesh have dropped back to below where they were before farmers started adopting Bt cotton.