Grades
U.S. No. 1.
U.S. Commercial.
U.S. No. 2.
Tolerances
En route or at Destination. 10% total defects including 7% for external defects (including not more than 5% for external quality defects); 7% for internal defects (including not more than 5% for internal qualty defects); including 2% for potatoes which are frozen or affected by soft rot or wet breakdown.
Good Delivery Guidelines:
14% total, including 10% internal defects, 10% external defects, including 3% soft rot
Common Defects:
Damage by:
(a) Bruising when removal causes a loss of more than 5% of the total weight of the potato, or when the area affected is more than 5% of the surface in the aggregate.
(b) Surface discoloration when the areas are light tan or light brown and do not blend, score as damage when more than 30% of the surface is affected. When the areas are darker than light tan or light brown in color, score as damage when more than 15% of the surface is affected.
(c) Greening when removal causes a loss of more than 5% of the total weight of the potato or, when materially detracting from the appearance of the potato. Green color affecting more than 25% of the surface in the aggregate is considered materially detracting.
(d) Growth cracks when the growth crack(s) affects more than 1/2 the length of the potato in the aggregate on round varieties or more than 1/3 the length in the aggregate on long varieties.
(e) Surface scab when more than 5% of the surface in the aggregate is affected.
(f) Silver scurf when affecting more than 50% of the surface area.
(g) Internal black spot when removal causes loss of more than 5% of the total weight of the potato.
Serious damage by:
(a) Bruising when removal causes a loss of more than 10% of the total weight of the potato, or when the area affected is more than 10% of the surface in the aggregate.
(b) Surface discoloration when the areas are light tan or light brown and do not blend, score as serious damage when more than 60% of the surface is affected. When the areas are darker than light tan or light brown in color, score as serious damage when more than 30% of the surface is affected.
(c) Greening when removal causes a loss of more than 10% of the total weight of the potato or, when seriously detracting from the appearance of the potato. Green color affecting more than 50% of the surface in the aggregate is considered seriously detracting.
(d) Growth cracks when more than 3/4 the length of the potato
(e) Surface scab when more than 25% of the surface in the aggregate is affected.
(f) Silver scurf when its severity causes a wrinkling of the skin over more than 50% of the surface.
(g) Internal black spot when removal causes loss of more than 10% of the total weight of the potato.