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United States Department of Agriculture

Agricultural Research Service

Title: Current Resistance Management Strategies for Bt Corn in the United States

Authors
item Matten, Sharlene - USEPA, OPP, BPPD
item Hellmich, Richard
item Reynolds, Alan - USEPA, OPP, BPPD

Submitted to: Transgenic Crop Protection: Concepts and Strategies
Publication Type: Book / Chapter
Publication Acceptance Date: November 1, 2002
Publication Date: June 1, 2004
Citation: Matten, S.M., Hellmich II, R.L., Reynolds, A. 2004. Current resistance management strategies for Bt corn in the United States. In: Koul, O., Dhaliwal, G.S., editors. Transgenic Crop Protection: Concepts and Strategies. Chapter 8. Enfield, NH, USA/Plymouth, UK: Science Publishers, Inc. p. 261-288.

Technical Abstract: Transgenic crops could revolutionize the way pest insects are managed. Scientists are concerned that high selection pressure could lead to the development of insects that are resistant to these new plants. The U.S. Environmental Protection Agency (EPA) has required an unprecedented insect resistance management (IRM) program for Bt crops. This book chapter focuses on IRM strategies for Bacillus thuringiensis (Bt) corn in the United States. The specific IRM strategies and requirements for Bt corn in the U.S. have been developed by a coalition of stakeholders including EPA, USDA, academic researchers, industry, seed companies, public interest groups, and growers. Many of these stakeholders recognize that IRM strategies need to be scientifically-sound, practical, flexible, implementable, and sustainable. IRM requirements for Bt corn include a 20% mandatory non-Bt corn refuge in the Corn Belt and a 50% mandatory non-Bt corn refuge in cotton-growing areas to be planted within ½ mile (¼ mile or closer preferred) to mitigate insect resistance. In-field refuges consisting of strips of at least four rows are allowed. There are also requirements for annual resistance monitoring, remedial action plan, grower education, grower compliance, research, and annual reporting. The Cry1Ab registrations for Bt11 and MON810 field corn hybrids and the Cry1F registrations for TC1507 field corn hybrids will automatically expire at midnight on October 15, 2008. Additional IRM research on the effect of north-south movement by corn earworm and high use of insecticide sprays will allow current IRM strategies to be further improved for greater long-term sustainability.

Last Modified: 9/20/2014
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