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Living Organisms Serving As Biopesticides, Genetically Modified Organisms As Biopesticide Producers, Disease Resistance In CropsNatural Chemical Defenses, Herbicide-Resistant Crops

Plants, growing in the wild or in cultivation, face numerous threats from insects, bacteria, viruses, and fungi, as well as from other plants. Biopesticides are inert substances or living organisms that can help protect plants from such threats. Chemical pesticides can offer similar protection but, by contrast, are neither alive nor made by living organisms.

A variety of chemicals produced by plants help ensure that parasites, predators, plant feeders, and herbivores seldom increase in number sufficiently to destroy the plant populations they prey upon. Chemicals found in very low concentrations in certain plants have been found to help keep locusts from feeding on those plants, and some trees produce nearly 1,000 different chemical compounds that help them resist herbivores and parasites.

Some crops (e.g. corn) are being engineered to contain both herbicide tolerance and the BT toxin. Generally, the use of herbicide-tolerant crops will likely increase the use of herbicides. This has the potential to increase environmental pollution since it might increase the farmers' reliance on chemicals rather than mechanical and other means of weed control.

David Pimentel


Paoletti, Maurizio G., and David Pimentel. "Genetic Engineering in Agriculture and the Environment." BioScience 46, no. 9 (1996): 665-673.

Pimentel, David, ed. Techniques for Reducing Pesticide Use: Economic and Environmental Benefits. Chichester, U.K.: John Wiley & Sons, 1997.

Pimentel, David, and Hugh Lehman, eds. The Pesticide Question: Environment, Economics, and Ethics. New York: Chapman and Hall, 1993.

Internet Resource

Religion and Ethics Newsweekly. Harvest of Fear. Public Broadcasting System. <http://www.pbs.org/wgbh/harvest/2001/>.

Additional topics

Medicine EncyclopediaGenetics in Medicine - Part 1