In a major win for the biotech industry, the U.S. government yesterday gave Monsanto the green light to sell corn that has been genetically modified to resist rootworm disease, the most significant threat to the crop. The effort to combat rootworm has been the single biggest reason farmers use pesticides, so the decision will be a test case of whether genetically modified crops will benefit the environment by reducing use of toxic chemicals, as the industry claims. That possibility was cited by the U.S. EPA as a major factor in its decision to approve Monsanto’s corn — a decision it acknowledged was made in the face of lingering questions about the potential environmental impact of the altered seed. For the most part, the GM corn will be used as animal feed, so people will only eat it indirectly, but it could also be used in edible products such as corn syrup.