Feb 24 After more than 15 years of using
genetically modified crops, U.S. farmers are continuing to see
an array of benefits, but the impacts on the environmental and
on food production are mixed, and high farmer use of a popular
herbicide on GMO crops is a cause for ongoing concern, according
to a report issued by the U.S. Department of Agriculture.
"We are not characterizing them (GMO crops) as bad or good.
We are just providing information," said Michael Livingston, a
government agricultural economist and one of the authors of the
report, prepared by the USDA's Economic Research Service (ERS).
The report, released online on Feb. 20, comes at a time when
GMO crops are under intense scrutiny. Consumer groups are
calling for tighter regulation of crop research and production
and seeking mandatory labeling of foods made with GMOs;
environmentalists are reporting increasing concerns about weed
resistance and insect resistance to the crops and the chemicals
used on them; and some scientific studies are reporting that the
chemicals used on the crops are linked to disease and illness.
As well, the report comes as the USDA and the Environmental
Protection Agency are in the final stages of approving the
commercialization of a new GMO crop and chemical product package
developed by Dow AgroSciences, a unit of Dow Chemical.
Genetically modified crops have become wildly popular with
U.S. farmers since Monsanto Co introduced
herbicide-tolerant "Roundup Ready" soybeans in the mid-1990s.
Since then, Monsanto and other seed and chemical companies have
introduced a variety of corn, soybeans, cotton, canola and
others crops that tolerate being sprayed with herbicide or
GMO crops were planted on about 169 million acres (68
million hectares) in the U.S. in 2013, about half the total land
used for crops, the report said.
The seeds are patented and cost more than conventional seeds
- the price of GMO soybean and corn seeds grew by about 50
percent between 2001 and 2010, according to the report. But the
companies that sell them say they make weed and insect
management easier for farmers and can help increase production.
But in its report, the ERS researchers said over the first
15 years of commercial use, GMO seeds have not been shown to
definitively increase yield potentials, and "in fact, the yields
of herbicide-tolerant or insect-resistant seeds may be
occasionally lower than the yields of conventional varieties,"
the ERS report states.
Several researchers have found "no significant differences"
between the net returns to farmers who use GMO herbicide
tolerant seeds and those who use non-GMO seeds, the report
GMO crops that prevent yield losses to pests is more helpful
to farmers financially, allowing crops more yield potential and
higher monetary returns, the report states. As well, insecticide
use on corn farms was down to 0.02 pound per acre in 2010, down
from 0.21 pound per acre in 1995, the report states.
But while insecticide use has gone down, herbicide use on
GMO corn is rising, the report states. Herbicide use on GMO corn
increased from around 1.5 pounds per planted acre in 2001 to
more than 2.0 pounds per planted acre in 2010. Herbicide use on
non-GMO corn has remained relatively level during that same time
frame, the ERS said.
And the over reliance on glyphosate has translated to an
increase in weed resistance, which makes crop production much
harder. Glyphosate is the chief ingredient in Roundup herbicide
sold by Monsanto, and its use has translated to the glyphosate
resistance seen in 14 weed species and biotypes in the United
States, according to ERS.
Researchers have thousands of tests underway in U.S. fields
for new crops, ERS reported. As of September 2013, about 7,800
releases have been approved for genetically engineered (GE)
corn, more than 2,200 for GE soybeans, more than 1,100 for GE
cotton, and about 900 for GE potatoes.
Of those releases, 6772 were for GE varieties with herbicide
tolerance, 4,809 for insect resistance, and 4,896 for product
quality such as flavor or nutrition, and 5,190 for drought
Monsanto has the most authorized field releases with 6,782,
followed by DuPont Pioneer, with 1,405.