Yesterday, the National Research Council of the National Academy of Sciences released a comprehensive report analyzing the effect on biotech crops on farmers and the environment. The press release accompanying the study notes:
Many U.S. farmers who grow genetically engineered (GE) crops are realizing substantial economic and environmental benefits—such as lower production costs, fewer pest problems, reduced use of pesticides, and better yields—compared with conventional crops, says a new report from the National Research Council. However, GE crops resistant to the herbicide glyphosate—a main component in Roundup and other commercial weed killers—could develop more weed problems as weeds evolve their own resistance to glyphosate. GE crops could lose their effectiveness unless farmers also use other proven weed and insect management practices.
The development of weeds resistant to herbicides is not a problem peculiar to biotech crops, but is likely exacerbated by the fact that so many biotech varieties incorporate resistance to a single herbicide, glyphosate. The good news is that new varieties are including tolerance to other herbicides. Mixing and matching these crops will better control the development of herbicide resistant weeds.
The new NRC report also notes:
The economic effects of GE crops on farmers who grow organic and conventional crops also need further study, the report says. For instance, organic farmers are profiting by marketing their crops as free of GE traits, but their crops' value could be jeopardized if genes from GE crops flow to non-GE varieties through cross-pollination or seed mingling.
As I have explained before, organic standards are a process standard which means that organic farmers can easily solve any problem with "contamination" by setting reasonable tolerance standards.
Go here to download the whole NRC report.