U.S. farmers have embraced genetically engineered (GE) seeds for
soybeans, cotton, and corn in the 15 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
The data for this chart are found in Adoption
of Genetically Engineered Crops in the U.S., a data product on
the ERS site.
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.