Standardized Resistance Management Recommendations for Bt Corn in 2000

March 17, 2000
After the U.S. Environmental Protection Agency (EPA) issued a brief statement on January 17 about the recommended measures for resistance management in Bt corn in 2000, many newspapers included articles, and many television stations featured reports, about the announcement. Some of the articles and reports communicated accurately that the "new measures for resistance management in Bt corn" were not new at all and would have little new effect on corn growers and vendors of Bt corn in 2000. Unfortunately, some articles and reports suggested that the EPA's announcement was a result of pressure from environmental groups who have been challenging the use of genetically modified (GM) crops. These articles and reports suggested that the "new measures for resistance management in Bt corn" might have dire consequences on corn growers and vendors of Bt corn and represent the concern that the United States now has for Bt corn and other GM crops. These latter suggestions could not be farther from the truth.

Scientists and the agricultural industry had been awaiting the announcement by the EPA in January for a long time. Most of the requirements announced by the EPA were consistent with the requirements suggested in a proposal that was made last April to the EPA by the Ag Biotech Stewardship (ABS) Working Group. And the requirements had been developed, in large part, by research and extension entomologists of the North Central Regional Research Project (NC-205), Ecology and Management of European Corn Borer and Other Stalk-Boring Lepidoptera. Their work had resulted in North Central Regional Extension Publication NCR602, Bt Corn & European Corn Borer: Long-Term Success Through Resistance Management, published in 1997.

Well before Bt-corn hybrids were introduced in 1996, university and ag-industry entomologists were concerned about the potential for target insects (especially European corn borer) developing resistance to the Bt protein in Bt corn. Consequently, scientists have been working toward an acceptable set of requirements for insect resistance management strategies associated with Bt corn. The announcement by the EPA affirmed the consensus suggestion of a minimum 20% non-Bt-corn refuge in principal corn-growing areas. Since 1996 Bt-corn vendors have been requiring corn growers to sign agreements to plant non-Bt-corn refuges, and university and industry entomologists have been educating growers about the importance of insect resistance management strategies. The EPA's announcement also affirmed the importance of monitoring fields for surviving corn borers and voluntary measures to protect nontarget insects such as the monarch butterfly. Most of these recommendations were outlined first in 1997 in the aforementioned NCR602 publication.

In summary, the EPA's announcement was made at the behest of scientists who have been developing insect resistance management strategies for years. These same scientists will continue to conduct research to develop appropriate monitoring plans and tools and to study the concerns regarding nontarget organisms. As more research is conducted and results are obtained, Bt corn management recommendations will be amended to accommodate new, important findings.

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Author: Kevin Steffey