No. 5 Article 1/May 6, 2011

A Future of Seed Mixtures in the Corn Belt Seems Certain: Potential Consequences

The U.S. Environmental Protection Agency (EPA) has given regulatory approval to several companies to move forward with the full-scale commercialization of Bt hybrids in which a seed mixture forms the basis of resistance management. A paper was recently published in the Journal of Economic Entomology (Vol. 104, No. 2, pp. 343-352; DOI: 10.1603/EC10388) titled "Seeds of Change: Corn Seed Mixtures for Resistance Management and Integrated Pest Management." The lead author is David Onstad, a professor in the University of Illinois Department of Crop Sciences. David is an internationally respected modeler and has been instrumental in developing models that help the scientific community and the EPA better understand how resistance to Bt corn may develop. Provided are some summary quotes from this important and timely article.

These statements are worthy of reflection as the industry transitions to the new paradigm of 95-to-5 seed blends across the Corn Belt. The authors of this paper represent a diversity of our land-grant institutions: University of Illinois, University of Wisconsin, University of Minnesota, Purdue University, Michigan State University, Iowa State University, Kansas State University, and Penn State University. Scientists from additional organizations contributed to the article, including the USDA-ARS, the Illinois Natural History Survey, and the Ontario Ministry of Agriculture.

Another significant consequence of the seed mixture infrastructure emerging within the corn insect protection arena is increasing pressure on the long-term sustainability of the soil insecticide market. As the number of refuges configured as blocks, strips, or separate fields declines, soil insecticide use should also be reduced. Ultimately, loss of soil insecticide products will result in a reduced flexibility for producers to effectively manage economic infestations of white grubs, wireworms, and other soil insects. In addition, if resistance develops to Bt hybrids and becomes widespread, growers will need to have some remaining tools to manage insect pests of corn. It remains to be seen whether some groups within the agribusiness sector are interested in maintaining their investments in this competitive arena just in case resistance develops or to offer products targeted against secondary soil insect pests.--Mike Gray

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