Adoption of Genetically Engineered Crops Continues
To Increase
Jorge
Fernandez-Cornejo
Adoption of genetically engineered (GE) soybeans,
cotton, and corn with herbicide tolerance (HT) and/or
insect resistance (Bt) traits by U.S. farmers has
been rapid over the 11-year period following commercial
introduction. HT crops survive certain potent herbicides,
enabling growers who adopt these varieties to control
pervasive weeds more effectively. In the U.S., HT
soybean adoption has expanded more rapidly and widely
than other GE crops, reaching 89 percent of soybean
acreage in 2006. The second most adopted variety,
HT cotton, accounted for 65 percent of cotton acreage.
Bt crops contain a gene from the
soil bacterium Bacillus thuringiensis that
produces a protein toxic to specific insects. Bt
seed use is concentrated in areas with high levels
of infestations of targeted pests, so acreage shares
for Bt corn and cotton are lower than for HT soybeans
and cotton and vary widely across States. Bt cotton,
which controls tobacco budworm, bollworm, and pink
bollworm, was planted on 57 percent of U.S. cotton
acreage in 2006—ranging from 17 percent in
California to 83 percent in Louisiana. The U.S.
acreage share of Bt corn leveled off during 1999-2002
because farmers with the greatest need to protect
against the European corn borer had already adopted
Bt corn. Adoption of Bt corn has since expanded,
reaching 40 percent of corn acreage in 2006, following
the introduction of a Bt variety to control corn
rootworm.
According to ERS research, U.S.
farmers are realizing tangible economic benefits
from adopting these GE crops, such as higher yields,
lower pesticide costs, and savings in management
time. The impacts of GE crops vary with the crop,
technology, pest infestation levels, and other factors.
In addition to corn, soybeans and
cotton, U.S. farmers have adopted HT canola and
virus-resistant papaya and squash. Moreover, other
GE traits are in various stages of development.
For example, USDA’s Animal and Plant Health
Inspection Service has approved 1,256 field testing
applications for crops with resistance to virus,
712 for resistance to fungus, 1,292 for improved
agronomic properties (such as resistance to cold,
drought, and salinity), and 2,687 for improved product
quality (such as crops that increase protein and
oil content, and crops with added vitamins and iron).
Worldwide, an estimated 220 million
acres of biotech crops with HT and/or Bt traits
were planted in 21 countries in 2005. The U.S. accounts
for about 55 percent of this amount, and six countries
combined (Argentina, Canada, Brazil, China, Paraguay,
and India) account for nearly 43 percent.
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