Agriculture Reference
In-Depth Information
Weeds are such a pervasive pest for soybeans, corn, and cotton that over
90 percent of U.S. planted acreage for each crop has been treated with herbi-
cides in recent years. The acreage share for HT soybeans has expanded more
rapidly than that for HT varieties of cotton and corn, reaching 87 percent of
U.S. soybean acreage in 2005.
Insect-resistant crops contain a gene from the soil bacterium
Bacillus
thuringiensis
(Bt) that produces a protein toxic to specific insects. Acreage
shares for Bt cotton and corn are lower than those for HT soybeans and cotton,
and adoption is more concentrated in areas with a high level of infestation of
targeted pests (insect infestation varies much more widely across locations
than does weed infestation). Farmers planted Bt cotton to control tobacco
budworm, bollworm, and pink bollworm on 52 percent of U.S. cotton acreage
in 2005. Bt corn, originally developed to control the European corn borer, was
planted on 35 percent of corn acreage in 2005, up from 24 percent in 2002.
The recent increase 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 even more destructive to corn yield than the
European corn borer (Comis).
Other GE crops planted by U.S. farmers over the past 10 years include HT
canola, virus-resistant papaya, and virus-resistant squash (table 2). In addition,
Bt potato varieties were introduced in 1996 but withdrawn from the market
after the 2001 season, and a tomato variety genetically engineered to remain
on the vine longer and ripen to full flavor after harvest was introduced in 1994
but was withdrawn from the market after being available sporadically for
several years.
U.S. Farmers Expect to Profit from Adopting GE Crops
According to USDA's Agricultural and Resource Management Surveys
(ARMS) conducted in 2001-03, most of the farmers adopting GE corn, cotton,
and soybeans indicated that they did so mainly to increase yields through
improved pest control (figure 7). Other popular reasons for adopting GE crops
were to save management time and make other practices easier and to decrease
pesticide costs. These results confirm other studies showing that expected
profitability increases through higher yields and/or lower costs (operator labor,
pesticides) positively influence the adoption of agricultural innovations.
