Impacts of GE Crops on Pesticide Use
- Impacts of GE Crops on Pesticide Use – The 2012 Environmental Sciences Europe Paper
- Herbicide Use on GE, Herbicide-Tolerant Crops
- 2,4-D and Dicamba – Possible Impacts of Second-Generation Herbicide-Tolerant Crops
The introduction of genetically engineered (GE), herbicide-resistant crops in 1996 quickly transformed cotton, corn, and soybean weed management systems. Use of the broad-spectrum herbicide glyphosate rose rapidly, displacing a long list of other active ingredients. Yet over time, excessive reliance on one weed management tactic (herbicides), and one herbicide active ingredient (glyphosate), triggered inevitable shifts in weed communities and the emergence of resistant weed phenotypes.
The M2M pesticide use database has been used in conjunction with a simulation model to quantify the impacts of GE crops on pesticide use in the U.S. Future work will focus on creating new tools that encompass for all GE crops:
- Impacts on the number of pesticides applied during the growing season, average application rates and acre-treatments, and pounds applied.
- In the case of Bt crops, the volume of Bt endotoxins produced, compared to the pounds of insecticides displaced by choosing a Bt cultivar.
- Environmental impacts per acre of GE crop production.
Impacts of GE Crops on Pesticide Use – The 2012 Environmental Sciences Europe Paper
Herbicide Use on GE, Herbicide-Tolerant Crops
- Use of the glyphosate herbicide has increased dramatically in the years since the introduction of glyphosate-tolerant GE crops. Data from the USDA National Agricultural Statistic Service (NASS) shows that three quarters of corn acres and nearly all of soybean and cotton acres in the US are treated with glyphosate. See Trends in Glyphosate (Roundup) Use on Three Major GE Crops for more.
- The use of other herbicides such as 2,4-D and Dicamba has decreased as GE corn has become more prevalent, but has increased for soybeans and cotton. See the historical data:
2,4-D and Dicamba – Possible Impacts of Second-Generation Herbicide-Tolerant Crops
Several new 2,4-D tolerant traits are under development by Dow AgroSciences and are moving through the regulatory process. Approval of these traits, and their incorporation in a significant share of corn and soybean varieties, will result in exponential growth in the volumes of 2,4-D applied in regions producing significant acreages of GE corn and soybeans.
M2M projections of possible increases in 2,4-D use on next-generation, herbicide tolerant crops appear below. The increase in dicamba use could also be significant, if next-generation, dicamba tolerant crops are approved. Both 2,4-D and dicamba are prone to drift and can trigger damage to non-target vegetation, and both pose human health risks considerable greater than thought to be associated with exposures to glyphosate.
- Projections of 2,4-D Use on Three Major Crops if Next Generation 2,4-D Herbicide Tolerant Crops are Approved Without Restrictions
- Historical Use of 2,4-D on Major Crops, covering corn, cotton, soybeans, and wheat from 1970 to 2010
- Historical Use of Dicamba on Major Crops covering corn, cotton, soybeans, and wheat from 1970 to 2010
- Comments to EPA on 2,4-D Health Risks from 70 Health Care Professionals
- Reproductive Impacts and Birth Defects Associated with 2,4-D Exposures: Bibliography with Abstracts
- Cancer Risks Associated with 2,4-D Exposures: Bibliography with Abstracts
- Human Health Risks Associated with Dicamba Exposures: Bibliography with Abstracts