The report, by Dr Charles Benbrook, explores the impact of the adoption of GE corn, soybean, and cotton on pesticide use in the United States, drawing principally on data from the United States Department of Agriculture. The report finds that GE crops have been responsible for an increase of 174 million kilograms of herbicide use in the U.S. over the first 13 years of commercial use of GE crops (1996-2008).

This dramatic increase in the volume of herbicides applied swamps the decrease in insecticide use attributable to GE corn and cotton, making the overall chemical footprint of today’s GE crops decidedly negative. The report identifies, and discusses in detail, the primary cause of the increase - the emergence of herbicide-resistant weeds.

The steep rise in the amount of herbicide applied, as a result of the introduction of GE in the US, is not news to farmers. Weed control is now widely acknowledged as a serious management problem within GE cropping systems. Farmers and weed scientists across the heartland and cotton belt are now struggling to devise affordable and effective strategies to deal with the resistant weeds emerging in the wake of herbicide-tolerant crops.

But skyrocketing herbicide use is news to the public at large, which still harbours the illusion, fed by misleading industry claims and advertising, that GE crops are reducing pesticide use. Such a claim was valid for the first few years of commercial use of GE corn, soybeans, and cotton. But, as this report shows, it is no longer.

An accurate assessment of the performance of GE crops on pesticide use is important for reasons other than correcting the excesses of industry advertising. It is also about the future direction of agriculture, research, and regulatory policy.

In addition to toxic pollution, agriculture faces the twin challenges of climate change and burgeoning world populations. The GE crop industry’s current advertising campaigns promise to solve those problems, just as the industry once promised to reduce the chemical footprint of agriculture. Before we embrace GE crops as solution to these new challenges, we need a sober, data-driven appraisal of its track record on earlier pledges.

Without such assessments, Australian agriculture is likely to continue down the road preferred by the GE crop industry, a path that promises to maximize their profits by capturing a larger share of farm income, and limit the ability of plant breeders and other agricultural scientists to address other pressing goals of wider importance to society as a whole.

Source: Impacts of Genetically Engineered Crops on Pesticide Use: The First Thirteen Years