Classification of defects.

§ 51.3416 Classification of defects. External Defects Defects Maximum allowed for U.S. No. 1 processing Maximum allowed for U.S. No. 2 processing Air cracks 5% waste 10% waste. Blackleg 5% waste 10% waste. Bruises 5% waste 10% waste Cuts Smooth, not more than 10% of surface Smooth, not more than 1/3 of surface. Enlarged lenticels, discolored or sunken 5% waste 10% waste. Flea Beetle 5% waste 10% waste Folded end 5% waste 10% waste. Fusarium tuber rot 5% waste 10% waste. Grass, wireworm 5% waste 10% waste. Greening, light 5% waste 10% waste. Growth cracks See Footnote No. 2 10% waste. Grub 5% waste 10% waste. Ingrown sprouts 5% waste 10% waste. Nematodes 5% waste 10% waste. Rhizoctonia, solid or thick mounded Not more than 10% of surface Not more than 25% of surface. Rodent, bird damage 5% waste 10% waste. Scab, pitted 5% waste 10% waste. Scab, russet 25% of surface or 5% waste 50% of surface or 10% waste. Scab, surface 25% of surface or 5% waste 50% of surface or 10% waste. Scab, surface (elephant hide). 10% of surface or 5% waste 25% of surface or 10% waste. Second growth 5% waste 10% waste. Scaling, surface cracks—when cracked, thick and has depth 10% of surface or 5% waste 25% of surface or 10% waste. Sunburn 5% waste 10% waste. Sunken discolored areas 5% waste 10% waste. Internal Defects Defects Maximum allowed for U.S. No. 1 processing Maximum allowed for U.S. No. 2 processing Occurring outside of or not entirely confined to the vascular ring Internal Black Spot, Internal Discoloration, Vascular Browning, Fusarium Wilt, Net Necrosis, Other Necrosis, Stem End Browning 5% waste 10% waste. Occurring entirely within the vascular ring Hollow Heart or Hollow Heart with Discoloration Area affected not to exceed that of a circle 7/8 inch in diameter in a 10 ounce potato.  1 Area affected not to exceed that of a circle 1 1/4 inches in diameter in a 10 ounce potato.  1 Light Brown Discoloration (Brown Center) Area affected not to exceed that of a circle 7/8 inch in diameter in a 10 ounce potato.  1 Area affected not to exceed that of a circle 1 1/4 inches in diameter in a 10 ounce potato.  1 Internal Brown Spot and similar discoloration (Heat Necrosis) Not more than the equivalent of 3 scattered spots 1/8 inch in diameter in a potato 6 ounces in weight or 2 1/2 inches in diameter, or correspondingly lesser or greater number of spots in smaller or larger potatoes Not more than the equivalent of 6 scattered spots 1/8 inch in diameter in a potato 6 ounces in weight or 2 1/2 inches in diameter or correspondingly lesser or greater number of spots in smaller or larger potatoes. 1  Note: Or correspondingly lesser or greater areas in smaller or larger potatoes.