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

The report finds that GE crops increased overall pesticide use by 318.4 million pounds between 1996 and 2008. While Bt crops reduced insecticide use by 64.2 million pounds, herbicide-tolerant (HT) crops increased herbicide use by 382.6 million pounds, primarily driven by HT soybeans. The author attributes this trend to the emergence of glyphosate-resistant weeds and the industry's shift toward 'stacked' traits, which the report argues will further increase pesticide volumes and environmental risks.

• Between 1996 and 2008, the adoption of GE crops resulted in a net increase of 318.4 million pounds of pesticides applied in the United States compared to a scenario without HT and Bt seeds.
• Herbicide-tolerant (HT) crops caused a total increase of 382.6 million pounds of herbicides over 13 years, with HT soybeans responsible for 92% of this increase (351 million pounds).
• Bt corn and cotton consistently reduced insecticide use, totaling a reduction of 64.2 million pounds over the 13-year period, with Bt corn contributing 32.6 million pounds and Bt cotton contributing 31.6 million pounds.
• The trend in pesticide use shifted over time; GE crops reduced overall pesticide use during the first three years (1996-1998), but use increased by 20% in 2007 and 27% in 2008.
• The increase in herbicide use is primarily driven by the emergence of glyphosate-resistant (GR) weeds and the industry's reliance on glyphosate, which has led to an epidemic of resistant species infesting millions of acres.
• Specific high-impact glyphosate-resistant weeds include Palmer amaranth (pigweed), which has spread rapidly across the South, and horseweed (marestail), which infests several million acres in at least 16 states.
• The margin of difference in herbicide use between GE and conventional crops has grown because conventional farmers have shifted to more potent, lower-dose herbicides, while glyphosate use rates on HT acres have risen.
• The biotechnology industry is responding to resistant weeds by developing 'stacked' traits, including crops resistant to multiple herbicides or enhanced resistance to higher doses of glyphosate, which the report argues will further increase pesticide volumes.
• The report warns that the use of multiple-herbicide resistant crops will lead to the increased application of older, more toxic chemicals such as 2,4-D, dicamba, and paraquat.

APA

Benbrook, C. (2009). Impacts of Genetically Engineered Crops on Pesticide Use: The First Thirteen Years. Union of Concerned Scientists. https://www.ucs.org/sites/default/files/2019-10/GE-crops-and-pesticide-use.pdf

Chicago

Benbrook, Charles. Impacts of Genetically Engineered Crops on Pesticide Use: The First Thirteen Years. Union of Concerned Scientists, 2009. https://www.ucs.org/sites/default/files/2019-10/GE-crops-and-pesticide-use.pdf.

Wikipedia

{{cite report |last1=Benbrook |first1=Charles |title=Impacts of Genetically Engineered Crops on Pesticide Use: The First Thirteen Years |publisher=Union of Concerned Scientists |date=November 2009 |url=https://www.ucs.org/sites/default/files/2019-10/GE-crops-and-pesticide-use.pdf |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{benbrook2009impacts, author = {Benbrook, Charles}, title = {{Impacts of Genetically Engineered Crops on Pesticide Use: The First Thirteen Years}}, institution = {Union of Concerned Scientists}, year = {2009}, month = nov, url = {https://www.ucs.org/sites/default/files/2019-10/GE-crops-and-pesticide-use.pdf}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }