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United States Department of Agriculture

Agricultural Research Service

Research Project: DISCOVERY AND DEVELOPMENT OF NATURAL PRODUCT-BASED WEED MANAGEMENT METHODS Title: Environmental Impacts of Transgenic Herbicide-Resistant Crops

Authors
item Cerdeira, Antonio - EMPRABA - BRAZIL AG. DEPT
item Duke, Stephen

Submitted to: Review Article
Publication Type: Review Article
Publication Acceptance Date: May 8, 2007
Publication Date: June 15, 2007
Citation: Cerdeira, A.L., Duke, S.O. 2007. Environmental Impacts of Transgenic Herbicide-Resistant Crops. Review Article. 2, No. 033:1-14.

Interpretive Summary: Transgenic glufosinate- and glyphosate-resistant crops are currently commercialized, and bromoxynil-resistant crops have been removed from the market for economic reasons. Glyphosate-resistant cotton and soybean have become dominant in those countries where they can be grown. Potential effects of glufosinate and glyphosate on contamination of soil, water, and air are minimal, compared to that caused by the herbicides that they replace when herbicide-resistant crops (HRCs) are adopted. No risks have been found with food or feed safety or nutritional value in products from currently available HRCs. Both glufosinate- and glyphosate-resistant crops promote the adoption of reduced- or no-tillage agriculture, reducing environmental degradation by agriculture. Some weeds species in glyphosate-resistant crops have evolved resistance to glyphosate. Weed species that are naturally resistant to glyphosate have occupied ecological niches vacated by susceptible weed species in glyphosate-resistant crops. Transgene flow with HRCs is a concern for commercial and ecological reasons. In canola, rice, and bentgrass, herbicide resistance transgenes have been found in fields that are supposed to be non transgenic. Under some circumstances, transgene flow (introgression) to plants that might become problems in natural ecosystems may be the largest risk of HRCs.

Technical Abstract: Transgenic glufosinate- and glyphosate-resistant crops are currently commercialized, and bromoxynil-resistant crops have been removed from the market for economic reasons. Glyphosate-resistant cotton and soybean have become dominant in those countries where they can be grown. Potential effects of glufosinate and glyphosate on contamination of soil, water, and air are minimal, compared to that caused by the herbicides that they replace when herbicide-resistant crops (HRCs) are adopted. No risks have been found with food or feed safety or nutritional value in products from currently available HRCs. Both glufosinate- and glyphosate-resistant crops promote the adoption of reduced- or no-tillage agriculture, reducing environmental degradation by agriculture. Some weeds species in glyphosate-resistant crops have evolved resistance to glyphosate. Weed species that are naturally resistant to glyphosate have occupied ecological niches vacated by susceptible weed species in glyphosate-resistant crops. Transgene flow with HRCs is a concern for commercial and ecological reasons. In canola, rice, and bentgrass, herbicide resistance transgenes have been found in fields that are supposed to be non transgenic. Under some circumstances, transgene flow (introgression) to plants that might become problems in natural ecosystems may be the largest risk of HRCs.

Last Modified: 11/27/2014
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