Crop Biotech Update

Strategy to Delay Insecticide Resistance

January 13, 2012

With Bt crops planted since 1996, government regulatory agencies worldwide have advised farmers to follow the proportional area of refuges to be planted and the distance from the Bt crop fields. Recently, a precise method to facilitate the identification of habitats that are efficient and the maximum distance at which refuge can be planted have been developed by researchers from the University of Arizona (UA).

The paper published in the Proceedings of the National Academy of Sciences revealed data from a span of eight years on the distribution and abundance of crops, application of the pesticide pyriproxyfen, and whitefly resistance to the pesticide. The research group developed spatially-explicit statistical models in the first four years of data that identified the crops affecting the spatial variation in resistance and the maximum distance at which these crops affected resistance. The next four years were focused on the prediction of resistance at the landscape level using the developed models. Results confirmed that refuges of cotton delayed the evolution of resistance and fields treated with pyriproxyfen accelerated the evolution of resistance.

UA Professor Yves Carrière, a co-author of the paper said that "the method and framework developed by their research could help refine the refuge strategy for many key pests" which also include the ones controlled through the use of Bt crops.

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