U.S. ECONOMY > American Industries > Agriculture > Adoption of Genetically Engineered Crops in the U.S.

Adoption of Genetically Engineered Crops in the U.S.: Extent of Adoption

Herbicide-tolerant (HT) crops, developed to survive application of specific herbicides that previously would have destroyed the crop along with the targeted weeds, provide farmers with a broader variety of options for effective weed control. Based on USDA survey data, HT soybeans went from 17 percent of U.S. soybean acreage in 1997 to 68 percent in 2001 and 89 percent in 2006. Plantings of HT cotton expanded from 10 percent of U.S. acreage in 1997 to 56 percent in 2001 and 65 percent in 2006. The adoption of HT corn has lagged soybeans and cotton, reaching 36 percent of U.S. corn acreage in 2006.

Insect-resistant crops containing the gene from the soil bacterium Bt (Bacillus thuringiensis) have been available for corn and cotton since 1996. These bacteria produce a protein that is toxic to specific insects, protecting the plant over its entire life. Plantings of Bt corn grew from 8 percent of U.S. corn acreage in 1997 to 26 percent in 1999, then fell to 19 percent in 2000 and 2001, before climbing to 29 percent in 2003 and 40 percent in 2006. The recent increases in acreage share may be largely due to the commercial introduction in 2003/04 of a new Bt corn variety that is resistant to the corn rootworm, a pest that may be more destructive to corn yield than the European corn borer, which was previously the only pest targeted by Bt corn. Plantings of Bt cotton expanded more rapidly, from 15 percent of U.S. cotton acreage in 1997 to 37 percent in 2001 and 57 percent in 2006.

Use of Bt corn will likely continue to fluctuate over time, based on expected infestation levels of European corn borer (ECB), and the corn rootworm which are the main pests targeted by the Bt corn. Similarly, adoption of Bt cotton depends on the expected infestation of Bt target pests, such as the tobacco budworm, the bollworm, and the pink bollworm. Adoption appears to have reached the low-growth phase, as adoption has already occurred on acreage where Bt protection is needed most. Insects have not posed major problems for soybeans, so insect-resistant varieties have not been developed.

These figures include adoption of "stacked" varieties of cotton and corn, which have both HT and Bt traits. Stacked cotton reached 39 percent of cotton plantings in 2006. Plantings of stacked corn are lower, making up only 15 percent of corn acres in 2006.

Adoption of all GE cotton, taking into account the acreage with either or both HT and Bt traits, reached 83 percent in 2006, versus 89 percent for soybeans. In contrast, adoption of all biotech corn was 61 percent.