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Book of Abstracts

11th IFOAM
Scientific Conference
11-15 August 1996
Copenhagen, Denmark

Abstract front page
Subject index
Athor index


Risks of transgenic crops and biocontrol organisms S10

Rissler, J.

Union of Concerned Scientists, 1616 P St., NW, Washington, DC 20036 USA

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Thirteen genetically engineered crops and three engineered biocontrol agents have been approved for commercialization in the United States. Dozens of transgenic agricultural biotechnology products are being tested in hundreds of field trials, including the first engineered invertebrate control agents, a nematode and a mite. The ecological risks of genetically engineered organisms are best understood in light of our experiences with releases of exotic species. Many will be harmless; a few may cause serious problems. Commercial-scale use of transgenic plants have the potential to cause several kinds of ecological risks. Some crops, engineered to contain new biologically advantageous genes, may themselves become weeds persisting infarmers' fields or invading wildlife habitats. Genes flowing from transgenic crops to wild relatives may become established in wild populations, create new weeds that may be more difficult to control, impact natural ecosystems, and harm centers of crop diversity. Widespread use of virus-resistant crops may lead to the development of new viral strains that may cause virus diseases in crops and wild plants. Insecticidal Bt crops may accelerate the evolution of resistance to Bt in insect pests, rendering Bt an ineffective biological control agent. Engineered invertebrates released to the environment potentially pose significant ecological risks because they typically reproduce rapidly and in great numbers; they play a variety of ecological roles, such as pests and beneficial predators and parasites; many are quite small and move considerable distances; and most may be difficult to control once released.