WEST LAFAYETTE, Indiana, Nov. 15 -- Purdue University issued the following news release: Sorghum has served as a food and feed crop for thousands of years, yet it can become poisonous under drought or freezing conditions. The problem is dhurrin, which breaks down to form prussic acid, also known as hydrogen cyanide. But Purdue University's Mitch Tuinstra, professor of plant breeding and genetics and scientific director of the Institute for Plant Sciences in the College of Agriculture, has deve more PR