Got corn? Unless it says otherwise, chances are that you're eating (or drinking) a genetically engineered product. About 90% of the corn grown in this country is genetically engineered, often to withstand spraying with the herbicide popularly known by the trade name Roundup. This isn't just about the ears of corn you shuck; Americans consume an extraordinary amount of corn products, including corn oil and high-fructose corn syrup. Now that Roundup-resistant weeds have emerged and are proving difficult to fend off, Dow AgroSciences is seeking federal approval for a new bioengineered corn that can survive spraying with a different herbicide. The FDA and EPA shouldn't go for it; creating products that have to withstand ever more powerful pesticides isn't what I'd call a sustainable agriculture plan. Studies have raised serious environmental questions about Roundup-ready crops. The heavy use of a single herbicide has resulted in the prevalence of weeds that are resistant to that herbicide; in addition, the loss of milkweed from spraying has been linked to dramatic drops in the monarch butterfly population throughout the Midwest.

Above, Renee Lafitte, a research fellow at DuPont Pioneer, in one of the various corn plots where the biotech company conducts research to develop drought-tolerant corn.