Seed companies will be required to encourage corn growers to take steps to keep rootworms from developing resistance to the the biopesticide known as Bt, reports DTN.
“Farmers who buy and plant Bt corn will not face any enforceable planting restrictions, such as EPA’s initial draft of rules recommended in January of 2015.” Instead, the EPA’s final version of the regulation would create a uniform system for reporting unacceptable levels of rootworm damage to corn, and seed companies would have to run education campaigns on the value of practices such as crop rotations, “pyramided” Bt hybrids with more than one resistance trait, and use of non-Bt varieties and insecticides.
Bruce Tabashnik, a University of Arizona entomologist, told DTN that “there is no apparent consequence for anyone not implementing these desired practices.” Nor does the final rule require farmers to devote a larger part of corn fields to non-Bt hybrids as refuges where rootworms would not breed and acquire tolerance for Bt. Tabashnik and other entomologists have argued that larger refuges are the best way to preserve the effectiveness of Bt corn. Most of the new rules would take effect in 2017.