The net result was a decrease in the overall pounds of herbicide applied. Impacts From Adopting Insect-Resistant Cotton Cotton production uses a large amount of insecticides and 77 percent of the 13 million acres devoted to upland cotton production in the 12 major states were treated with 18 million pounds of insecticides in 1997. Malathion was the top insecticide used on cotton, with farmers applying more than 7 million pounds of this chemical in 1997. While use of organophosphate insecticides and pyrethroid insecticides did not have significant changes associated with an increase in Bt adoption, there was a significant decrease in other insecticides, such as aldicarb. Summary Statistically controlling for factors other than adoption of genetically engineered seeds allows an understanding of the likely impacts of marginal changes in adoption on yields, profits, and pesticide use.
Impacts vary with the crop and technology examined.
Increases in adoption of herbicide-tolerant cotton were associated with significant increases in yields and variable profits, but were not associated with significant changes in herbicide use. Increases in adoption of herbicide-tolerant soybeans were associated with small increases in yields and variable profits, and significant decreases in herbicide use. Increases in adoption of Bt cotton resistant to insects in the Southeast were associated with significant increases in yields and profits and decreased insecticide use. Links Genetically Engineered Crops for Pest Management , in the Issues Center on the ERS website.