Agriculture Reference
In-Depth Information
A National Research Council study (2010) concurred that GE crops lead
to reduced pesticide use and /or lower toxicity compared to conventional
crops.
Insecticide use decreases with the adoption of Bt crops.
Generally, Bt
adoption is associated with lower insecticide use (table 4). Pounds of
insecticide (per planted acre) applied to corn and cotton crops have declined
over the course of the last 15 years (figure 12). (Results for cotton in 1999-
2001 were distorted because of the high application rates of the insecticide
Malathion during the boll weevil eradication program.)
Insecticide use on corn farms declined most years and had an overall drop
from 0.21 pound per corn planted acre of corn in 1995 (the year before Bt corn
was commercially introduced) to 0.06 in 2005 and 0.02 pound in 2010 (figure
12). Insecticide use has declined for
both
Bt adopters and nonadopters in
recent years. According to ARMS data, only 9 percent of all U.S. corn farmers
applied insecticides in 2010.
Econometric studies by ERS researchers have also found that, except for
recent years, Bt crop adoption led to decreases in insecticide use, controlling
for other factors.
For example, FernandezCornejo et al. (2003) show that the adoption of Bt
cotton in the Southeast region (which had higher rates of Bt adoption) was
associated with lower insecticide use on cotton in 1997. After controlling for
other factors, a 10-percent increase in Bt corn adoption was associated with a
decrease in insecticide use of 4.1 percent in 2001 (Fernandez-Cornejo and Li,
2005).
However, Bt corn adoption was not significantly related to insecticide use
in more recent years using 2005 data (Fernandez-Cornejo and Wechsler,
2012), as well as in a new ERS analysis using 2010 survey data (table 6).
Taken together, these results suggest that insect infestation levels on corn
were lower in recent years than in earlier years and are consistent with
findings by Hutchinson et al. (2010) that European corn borer populations
have steadily declined over the last decade.
Moreover, several researchers have shown that areawide suppression of
certain insects such as the European corn borer and the pink bollworm are
associated with the use of Bt corn and Bt cotton, respectively (see box, “Bt
Crop Adoption and Areawide Pest Suppression”).
