U.S. farmers have embraced genetically engineered (GE) seeds for soybeans, cotton, and corn in the 19 years since their commercial introduction. GE seeds have genes that provide specific traits such as herbicide tolerance (HT) and insect resistance. HT crops tolerate potent herbicides, allowing adopters of these varieties to control pervasive weeds more effectively.Insect-resistant (Bt) crops contain a gene from the soil bacterium Bacillus thuringiensis that produces a protein toxic to specific insects, protecting the plant over its entire life.
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See also Adoption of Genetically Engineered Crops in the U.S., a data product on the ERS website.
Although other traits are being developed (including virus and fungus resistance, cold and drought resistance, and enhanced protein, oil, or vitamin content), crops with HT and Bt traits are the most prominent GE crops currently on the market. While other crop varieties have been developed (e.g., HT canola, HT sugar beets, and HT alfalfa), corn, cotton, and soybeans make up the bulk of the acres planted to GE crops.
Despite the higher prices for GE seed compared to conventional seed, U.S. farmers are realizing economic benefits from increased crop yields, and/or lower pesticide costs and management time savings. The impacts of GE crops vary with the crop, technology, pest infestation levels, and other factors. For example, Bt crops may lead to yield gains and/or lower insecticide costs while herbicide tolerant crops leads to savings in management time. Moreover, farmers adopting the HT varieties for corn, cotton, and soybeans often substitute glyphosate for more toxic herbicides. HT crops also facilitate the adoption of conservation tillage.
Despite its net benefits, however, consumer concerns may have limited acceptance of GE crops, particularly in Europe. In addition, the reliance on glyphosate has recently led to the evolution of weed resistance to this herbicide, reducing the effectiveness of this weed-management tool.