BT Cotton Not So Eco Phriendly After All...

In some cases, Bt crops genetically engineered to produce their own insecticide require less pesticide than conventional crops, but scientists at Cornell University found that the effect can be short-lived. Their survey of Chinese farmers revealed that initially the farmers used fewer pesticide applications on Bt cotton. The Bt toxin killed the cotton's primary insect pest, bollworms. But soon the farmers had to apply pesticide to control unexpected outbreaks of other pests that were previously kept in check by both pesticides and an active bollworm population, and seven years after adopting the Bt technology they were using just as much pesticide as growers of conventional cotton. Since engineered seed costs two to three times as much as conventional seed, the renewed pesticide use meant the Bt cotton farmers' earnings fell below those of conventional cotton farmers. Read the study (pdf).