Reversing pest resistance to biotech cotton: The secret is in the mix
University Of Arizona
Credit: Peng Wan Insect pests that are rapidly adapting to genetically engineered crops threaten agriculture worldwide. Planting such non-Bt cotton refuges is credited with preventing evolution of resistance to Bt cotton by pink bollworm in Arizona for more than a decade. The ingenious strategy used in China entails interbreeding Bt cotton with non-Bt cotton, then crossing the resulting first-generation hybrid offspring and planting the second-generation hybrid seeds. This generates a random mixture within fields of 75 percent Bt cotton plants side-by-side with 25 percent non-Bt cotton plants. We know it works for millions of farmers in the Yangtze River Valley.