An organism is genetically modified by the introduction of foreign DNA into its endogenous genetic code. Genetically modified crops are also commonly referred to as transgenic crops. Two types of genetically modified crops that are widely used in agriculture are herbicide-resistance crops and insect-resistant crops.

Breeding crops for pest resistance has a long tradition that has had many successes; however, it is a slow and painstaking process. The development of biotechnology tools that allowed cutting and splicing of genetic sequences, along with advances in tissue culture, allowed a new approach to developing pest resistant crops--transgenic or genetically modified crops.

Plants that produce their own pesticides are genetically modified with foreign DNA that codes for a toxin. The first plant pesticide registered by Monsanto with the EPA was Bt-cotton, which was bioengineered to contain a gene that codes for the Bt Cry1Ac delta-endotoxin. This gene confers resistance to a certain group of insect pests (i.e. lepidopteran pests). Other genetically-engineered crops have followed, such as the widely planted, herbicide-resistant soybean, Roundup Ready .

Transgenic crops are regulated by the federal government (USDA-APHIS, FDA and EPA).

Ware, G.W. and Whitacre, D.M. 2004. The Pesticide Book, 6th Ed. MeisterPro Information Resources, Willoughby, OH. Pp. 317-331.

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