Engineered Crops Now Increasing Pesticide Use in the United States
(Beyond Pesticides, November 26, 2003) The planting of 550 million acres of genetically engineered (GE) corn, soybeans and cotton in the United States since 1996 has increased pesticide use by about 50 million pounds, according to a report released November 25, 3003 by the Northwest Science and Environmental Policy Center.
The report, Impacts of Genetically Engineered Crops on Pesticide Use in the United States: The First Eight Years, is the first comprehensive study of the impacts of all major commercial GE crops on pesticide use in the United States over the first eight years of commercial use, 1996-2003. It draws on official U.S. Department of Agriculture data on pesticide use by crop and state.
The report calculates the difference between the average pounds of pesticides applied on acres planted to GE crops compared to the pounds applied to otherwise similar conventional crops. In their first three years of commercial sales (1996-1998), GE crops reduced pesticide use by about 25.4 million pounds, but in the last three years (2001-2003), over 73 million more pounds of pesticides were applied on GE acres.
Substantial increases in herbicide use on Herbicide Tolerant(HT) crops, especially soybeans, accounted for the increase in pesticide use on GE acres compared to acres planted to conventional plant varieties. Many farmers have had to spray incrementally more herbicides on GE acres in order to keep up with shifts in weeds toward tougher-to-control species, coupled with the emergence of genetic resistance in certain weed populations.
“For years weed scientists have warned that heavy reliance on herbicide tolerant crops would trigger ecological changes in farm fields that would incrementally erode the technology’s effectiveness. It now appears that this process began in 2001 in the United States in the case of herbicide tolerant crops,” according to Dr. Charles Benbrook.
The report concludes that the other major category of GE crops, corn and cotton engineered to produce the natural insecticide Bacillus thuringiensis (Bt) in plant cells, continues to reduce insecticide use by 2 million to 2.5 million pounds annually. The increase in herbicide use on HT crop acres, however, far exceeds the modest reductions in insecticide use on acres planted to Bt crops, especially since 2001.
The 46-page report is posted at http://wwww.biotech-info.net/technicalpaper6.html.