By SOURAV MISHRA, published August 31, 2006 in Down to Earth – The developing countries’ wide acceptance of genetically modified seeds owes much to China — among the first to adopt this technology. Its flag-bearer crop is Bt cotton, introduced in China by Monsanto in 1996. It was thought that by injecting Bacillus thuringiensis (Bt) gene into cottonseeds, the American bollworm (Helicoverpa armigera), the major cotton pest, could be wiped out without resorting to a fusillade of expensive pesticides. But the belief that Bt cotton could help eradicate poverty in developing countries has been all but shattered following a recent study by the Cornell University in the us.
Tarnished: The study, Tarnishing Silver Bullets: Bt Technology Adoption, Bounded Rationality and the Outbreak of Secondary Pest Infestations in China, claims that in 2004, after seven years of using Bt cotton, the situation became as bad as it was earlier.
It says that since Bt cotton targets only the bollworm, populations of secondary insects — such as mirids — increased so much that farmers had to use pesticides up to 20 times during a growing season. This was similar to the situation before the advent of Bt cotton that had brought down pesticide use to an average 6.6 times.
… // …
What went wrong? The study, conducted jointly with the Centre for Chinese Agricultural Policy (ccap) and the Chinese Academy of Science, covered five provinces where close to five million farmers cultivate cotton with 65 per cent of the area under Bt cotton in 2004. Annual revenue calculations from 1999-2003 show that the average net revenue per ha was us $121 (about Rs 5,500) more for Bt crops. However, the situation reversed in 2004 with a spurt in mirid attacks. Bt farmers, who applied 1.6 kg/ha of pesticide to control secondary pests in 2001, had to use almost five times more pesticides (7.61 kg/ha) in 2004.
Read the whole article on this page of Down to Earth).