Ken Bell, a rice grower in southwestern Missouri, remembers that 2006 was shaping up to be one of those years farmers only dare to dream about. « Not only was the market up, » he told me, « but we had a good crop growing. »

Then on August 18, a Friday, Bell’s world collapsed. The United States Department of Agriculture (USDA) announced that traces of genetically modified rice produced by Bayer CropScience, a division of the huge German drug and chemical company, had somehow escaped test plots and found their way into rice fields in Texas, Arkansas, Missouri, Mississippi, and Louisiana. The GM crop was engineered to survive applications of Liberty Link, a Bayer herbicide. The USDA still does not know what caused the widespread contamination.

By the following Monday morning, worldwide markets for American long-grain rice had evaporated. Japan, Russia, Canada, the Philippines, Taiwan, and Iraq imposed restrictions on U.S. rice imports. The European Union demanded that all incoming U.S. rice be tested and certified as free of GM traits. Bell had incurred all of the up-front costs of what was to be that year’s bumper harvest, but suddenly no one would buy it. He lost more than $1.9 million. « It went from a great year to a disaster, » he said.