They are being developed to tolerate herbicides and resist pests and diseases.

Companies are also inserting genes directly into crop plants, hoping to develop more plant varieties that grow faster or resist pests more effectively.

Seeds designed to resist drought and pests are especially useful in tropical countries, where crop losses are often severe.

Such crops are typically altered to resist pests and chemicals.

That organism, and its offspring, will then have a genetic structure that lets them resist such pests.

Already, a majority of the cotton grown in China, the world's leading producer, is genetically engineered to resist pests.

It seldom needs fertilizer, and it resists diseases and pests, including deer.

Today such crops are typically altered to resist pests and chemicals.

Companies are engineering products that resist pests, including crops engineered to produce their own insecticides and new biological vehicles for pesticide delivery.

Scientists use agricultural biotechnology to create crops that resist pests and fight off disease.