Impacts of GE Crops on Pesticide Use



Introduction

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.

first nine years

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

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.