Farmers need to adopt better management practices to ensure that beneficial environmental effects of GE crops continue, the report says. In particular, farmers who grow GE herbicide-resistant crops should not rely exclusively on glyphosate and need to incorporate a range of weed management practices, including using other herbicide mixes. To date, at least nine species of weeds in the United States have evolved resistance to glyphosate since GE crops were introduced, largely because of repeated exposure. Federal and state government agencies, technology developers, universities, and other stakeholders should collaborate to document weed resistance problems and develop cost-effective ways to control weeds in current GE crops and new types of GE herbicide-resistant plants now under development.
Improvements in water quality could prove to be the largest single benefit of GE crops, the report says. Insecticide use has declined since GE crops were introduced, and farmers who grow GE crops use fewer insecticides and herbicides that linger in soil and waterways. In addition, farmers who grow herbicide-resistant crops till less often to control weeds and are more likely to practice conservation tillage, which improves soil quality and water filtration and reduces erosion.
However, no infrastructure exists to track and analyze the effects that GE crops may have on water quality. The U.S. Geological Survey, along with other federal and state environmental agencies, should be provided with financial resources to document effects of GE crops on U.S. waters
|Contact: Jennifer Walsh|
National Academy of Sciences