Bt cotton leads Chinese farmers to lose money: study

Genetically modified (GMO) insect-resistant cotton has caused Chinese farmers to lose money after a seven-year trial, the official Xinhua news agency reported on Wednesday, citing a joint study.
China is already the world's top grower of Bt cotton, which contains the Bacillus thuringiensis bacterial gene that kills bollworms. About 70 percent of its 2006 cotton acreage is estimated to be of the transgenic variety.
The Bt cotton was not effective in controlling secondary pests, although it did reduce pesticide use by more than 70 percent in the first three years, Xinhua cited the study as saying.
The study, the first to look at the longer-term economic impact of GMO cotton, was conducted by the Center for Chinese Agricultural Policy, the Chinese Academy of Sciences and Cornell University. It followed some 500 Chinese farmers.
"After seven years, populations of other insects such as mirids have increased so much that farmers are now having to spray their crops up to 20 times a growing season to control them," it said. Mirids are a type of leaf bug that can damage young cotton seedlings, potentially delaying harvests and reducing yield.
Farmers using Bt cotton had to spray as much as conventional farmers in the fourth year of the trial, which resulted in a net average income of 8 percent less than conventional cotton farmers. Bt seed is triple the cost of conventional seed.
"These results should send a very strong signal to researchers and governments that they need to come up with remedial actions for the Bt-cotton farmers," Xinhua quoted Per Pinstrup-Andersen, a Cornell professor who led the study, as saying.
"Otherwise, these farmers will stop using Bt cotton, and that would be very unfortunate."
In addition to cotton, China also allows commercial growing of GMO tomatoes, but not GMO rice. Scientists said Beijing has not approved commercial production of GMO rice because it is concerned about possible mutation of pests to develop resistance to the Bt toxin. China is also the world's largest importer of genetically modified soybeans, mainly from the United States and South American countries.