Bridges Trade BioRes • Volume 9 • Number 21 • 27th November 2009

GM Crops Cause Dramatic Increase in US Pesticide Use: Report

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The growing popularity of genetically modified (GM) corn, soybeans, and cotton has triggered an increase in pesticide use, a dramatic emergence of herbicide-resistant weeds, and a rise in the amount of chemical residues found in food, according to a new report published on Tuesday by US-based groups the Organic Center, the Union for Concerned Scientists, and the Center for Food Safety.

The report found that there was an additional use of 174 million kg (383 million lbs) of herbicide between 1996 - when the first biotech crops were released - and 2008. The rate of increase has spiked in recent years, shifting from a drop of 1 to 2 percent in the first four years of biotech crop use, to a 20 percent increase in 2007, and a 27 percent rise in 2008, the report said.

The groups pointed out that the use of insecticide has actually dropped by 64 million pounds since 1996, due to the introduction of GM corn and cotton, yet over the same period pesticide use has jumped by 318 million pounds. The group classifies herbicides, insecticides, and fungicides as types of pesticides.

This rise in herbicide use was caused by the introduction of crops that have been engineered to tolerate higher levels of weed killer, the study authors say. The most popular of these crops are the ‘Roundup Ready’ seeds produced by GM seed producer Monsanto. The seeds are known for their resistance to ‘Roundup’ brand herbicide.

“Herbicide resistance crops are incredibly popular with farmers. They help them manage their weed problems in ways traditional crops don’t,” said Mike Wach, managing director of science and regulatory affairs at the Biotechnology Industry Organization, of which Monsanto is a member.

The biggest impact of a rise in herbicides is the epidemic of herbicide-resistant weeds, which can damage crops and farming equipment, the report concludes. The authors explain that to get rid of these weeds, farmers must either spray more herbicide at an increasing rate or manually weed them out, the former being by far the most common method of elimination. In US cotton fields, some herbicide-resistant weed infestations have been so drastic that farmers have been forced to abandon cropland or hoe the weeds by hand.

“With glyphosate-resistant weeds now infesting millions of acres, farmers face rising costs coupled with sometimes major yield losses, and the environmental impact of weed management systems will surely rise,” said Charles Benbrook, chief scientist of The Organic Center.

The groups also criticised the high prices of GM seeds. The report found that GM corn would be almost three times more expensive than conventional seeds by 2010, and that newer, more enhanced biotech soybeans will cost 42 percent more than the original biotech soybeans. Biotech industries claim the higher prices are justified by the fact that the seeds bring farmers numerous side benefits.

The report predicts that GM corn, soybean, and cotton planted over the next five to 10 years will, “pose unique resistance management, crop health, food safety, and environmental risks. [Herbicide-tolerant] crops will continue to drive herbicide use up sharply, and those increases in the years ahead will continue to dwarf the reductions in insecticide use on [GM] crop acres.”

“This may be profitable for the biotech/pesticide companies, but it’s bad news for farmers, human health and the environment,” said Bill Freese, science policy analyst for the Center for Food Safety.

Additional information

The study can be found here: http://www.organic-center.org/science.pest.php?action=view&report_id=159

ICTSD Reporting; “Biotech crops cause big jump in pesticide use: report,” REUTERS, 17 November 2009; “GM crops causing a rise in pesticide use in US,” ECOLOGIST, 17 November 2009.