This regulation establishes a tolerance for combined residues of diflufenzopyr, 2-(1-[([3,5-difluorophenylamino]carbonyl)- hydrazono]ethyl)-3-pyridinecarboxylic acid, and its metabolites convertible to M1 (8-methylpyrido[2,3-d]pyridazin-5(6H)-one) in or on field corn stover, forage and grain. BASF Corporation requested this tolerance under the Federal Food, Drug, and Cosmetic Act (FFDCA), as amended by the Food Quality Protection Act of 1996 (Pub. L. 104-170).