This regulation establishes tolerances for combined residues of prothioconazole and prothioconazole-desthio, calculated as parent in or on grain, cereal, group 15 (except sweet corn, sorghum, and rice), and grain, cereal, forage, fodder and straw, group 16 (except sweet corn, sorghum, and rice) and sweet corn. Bayer CropScience requested these tolerances under the Federal Food, Drug, and Cosmetic Act (FFDCA).