Rapid Growth in Adoption of Genetically Engineered
Crops Continues in U.S.
Jorge
Fernandez-Cornejo
U.S. farmers have rapidly adopted genetically
engineered (GE) soybeans, cotton, and corn with
herbicide tolerance and/or insect resistance traits
over the 13 years since their commercial introduction.
According to ERS research, U.S. farmers are realizing
economic benefits from GE crops, including 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.
Herbicide-tolerant (HT) crops are treated with
certain effective herbicides, allowing adopters
of 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 92 percent of planted soybean
acreage in 2008. The second most adopted variety,
HT cotton, was planted on 68 percent of cotton
acreage. The level of HT corn adoption, which
had been modest in earlier years, has recently
accelerated, reaching 63 percent of U.S. corn
acreage.
Insect-resistant (Bt) crops contain a gene from
the soil bacterium Bacillus thuringiensis that
produces a protein toxic to specific insects. Bt
cotton, which controls tobacco budworm, bollworm,
and pink bollworm, was planted on 63 percent of
U.S. cotton acreage in 2008. Adoption of Bt corn
plateaued in the U.S. during 1998-2002 because
farmers who needed to protect their crops against
the European corn borer had already adopted it.
However, adoption of Bt corn is increasing again
since a Bt variety to control corn rootworm was
introduced in 2003. Bt corn was planted on 57 percent
of U.S. corn acreage in 2008.
The rapid increase in the adoption of crop varieties
with more than one GE trait (stacked traits) continues.
Corn varieties with both Bt and HT traits grew
from 1 percent of corn-planted acres in 2000 to
40 percent in 2008, while cotton varieties with
stacked traits increased from 20 to 45 percent
of cotton-planted acres in the same period.
In addition to corn, soybeans, and cotton, U.S.
farmers have adopted HT canola and virus-resistant
papaya and squash. Moreover, other GE crops are
in various stages of development. As of May 2008,
USDA’s Animal and Plant Health Inspection
Service had approved 1,311 field-testing applications
for crops with resistance to virus, 842 for resistance
to fungi, 2,200 for improved agronomic properties
(such as resistance to cold, drought, and salinity),
and 3,362 for higher product quality (including
crops with increased protein and/or oil content,
and crops with added vitamins and iron).
Worldwide,
more than 280 million acres of GE crops with HT
and/or Bt traits were planted in 23 countries in
2007, with the U.S. accounting for about 50 percent.
Argentina, Brazil, Canada, India, China, Paraguay,
and South Africa accounted for about 49 percent.
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