This regulation establishes tolerances for residues of boscalid, 3-pyridinecarboxamide, 2-chloro-N-(4'-chloro[1,1'-biphenyl]- 2-yl) in or on leafy greens subgroup 4A, except head and leaf lettuce, and leafy petioles subgroup 4B. Interregional Research Project No. 4 (IR-4) requested these tolerances under the Federal Food, Drug, and Cosmetic Act (FFDCA), as amended by the Food Quality Protection Act of 1996 (FQPA).