View all text of Subjgrp 578 [§ 51.1550 - § 51.1565]
§ 51.1564 - External defects.
External defects are defects which can be detected externally. However, cutting may be required to determine the extent of the injury. Some external defects are listed in Tables III, IV, V and VI.
Table III—External Defects
| Defects | Damage | Serious damage 1 | Air Cracks | When removal causes a loss of more than 5 percent of the total weight of the potato or when the air crack(s) affects more than 1/3 the length or diameter of the potato (whichever is greater) in the aggregate | When removal causes a loss of more than 10 percent of the total weight of the potato or when the air crack(s) affects more than 3/4 the length or diameter of the potato (whichever is greater) in the aggregate. | Artificial Coloring | When unsightly or when concealing any defect causing damage or when penetrating the flesh and removal causes loss of more than 5 percent of total weight of potato | When concealing a serious defect or when penetrating into the flesh and removal causes loss of more than 10 percent of total weight of potato. | Bruises (Not including pressure bruise and sunken discolored areas) | When removal causes a loss of more than 5 percent of the total weight of the potato or when the area affected is more than 5 percent of the surface in the aggregate (i.e., 3/4 inch on a 2 1/2 inch or 6 oz. potato). Correspondingly lesser or greater areas in smaller or larger potatoes | When removal causes a loss of more than 10 percent of the total weight of the potato or when the area affected is more than 10 percent of the surface in the aggregate (i.e., 1 1/4 inches on a 2 1/2 inch or 6 oz. potato). Correspondingly lesser or greater areas in smaller or larger potatoes. | Cuts | When one smooth cut affects more than 5 percent of the surface area | Cut(s) that affect more than 10 percent of the surface area in the aggregate or when a single side cut extends beyond 1/2 the length of the potato. | Dirt | When materially detracting from the appearance of the potato | When seriously detracting from the appearance of the potato. | Elephant Hide | When affecting over 10 percent of the surface area of the potato | When affecting over 25 percent of the surface area. | Enlarged Lenticels | When materially detracting from the appearance of the potato | When seriously detracting from the appearance of the potato. | External Discoloration (Areas that are light tan or lighter in color and blends should be ignored) | When more than 30 percent of the surface is affected by light tan or light brown colors which do not blend or when more than 15 percent of the surface is affected by colors darker than light tan or light brown | When more than 60 percent of the surface is affected by light tan or light brown colors which do not blend or when more than 30 percent of the surface is affected by colors darker than light tan or light brown. | Flattened or Depressed Areas/Pressure Bruises | When removal of underlying discolored flesh causes a loss of more than 5 percent of the total weight of the potato or when the flattened or depressed area(s) covers more surface area than allowed in Table IV. (See Table IV.) | When removal of underlying discolored flesh the causes a loss of more than 10 percent of the weight of the potato or when the flattened depressed area(s) covers more surface area than allowed in the Table IV. (See Table IV.) | Flea Beetle Injury | When materially detracting from the appearance or when removal causes a loss of more than 5 percent of the total weight of the potato or when the area affected is more than 5 percent of the surface in the aggregate | When seriously detracting from the appearance of the potato or when removal causes a loss of more than 10 percent of the weight of the potato or when the area affected is more than 10 percent of the surface in the aggregate. | Greening | When removal causes a loss of more than 5 percent of the total weight of the potato or when green color affects more than 25 percent of the surface in the aggregate | When removal causes a loss of more than 10 percent of the weight of the potato or when green color affects more than 50 percent of the surface in the aggregate. | 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; or, when the depth is greater than that as outlined in Table V. ( | When the growth crack(s) affects more than
3/4 the length of the potato in the aggregate or when the depth is greater than that as outlined in Table V. ( | Grub Damage | When removal causes a loss of more than 5 percent of the total weight of the potato or when affecting more than 5 percent of the surface area (i.e. more than 3/4 inch on a 2 1/2 inch or 6 ounce potato). Correspondingly lesser or greater areas in smaller or larger potatoes | When removal causes a loss of more than 10 percent of the total weight of the potato or when affecting more than 10 percent of the surface area (i.e. more than 1 1/4 inch on a 2 1/2 inch or 6 ounce potato). Correspondingly lesser or greater areas in smaller or larger potatoes. | Insects or Worms | (See Serious Damage.) | When present inside the potato. | Nematode (Root Knot) | When removal causes loss of more than 5 percent of total weight of potato | When removal causes loss of more than 10 percent of total weight of potato. | Rhizoctonia | When affecting more than 15 percent of the surface in the aggregate | When affecting more than 50 percent of the surface in the aggregate. | Russeting (On Non Russet Type) | When more than 50 percent of the surface is affected in the aggregate | N/A. | Rodent or Bird Damage | When removal causes a loss of more than 5 percent of the total weight of the potato or when affecting more than 5 percent of the surface area (i.e. more than 3/4 inch on a 2 1/2 inch or 6 ounce potato). Correspondingly lesser or greater areas in smaller or larger potatoes | When removal causes a loss of more than 10 percent of the total weight of the potato or when affecting more than 10 percent of the surface area (i.e. more than 1 1/4 inch on a 2 1/2 inch or 6 ounce potato). Correspondingly lesser or greater areas in smaller or larger potatoes. | Scab, Pitted | When removal causes a loss of more than 5 percent of the total weight of the potato or when scab affects an aggregate area of more than 1/2 inch. (Based on a potato 2 1/2 inches in diameter or 6 oz. in weight.) Correspondingly lesser or greater areas in smaller or larger potatoes | When the removal causes a loss of more than 10 percent of the total weight of the potato or when scab affects an aggregate area of more than 1 inch. (Based on a potato 2 1/2 inches in diameter or 6 oz. in weight.) Correspondingly lesser or greater areas in smaller or larger potatoes. | Scab, Russet | Smooth and affecting more than 1/3 of the surface or rough russet scab which affects more than 10 percent of the surface in the aggregate | Rough and affecting more than 25 percent of the surface in the aggregate. | Scab, Surface | When more than 5 percent of the surface in the aggregate is affected | When more than 25 percent of the surface in the aggregate is affected. | Second Growth | When materially detracting from the appearance of the potato | When seriously detracting from the appearance of the potato. | Silver Scurf | When affecting more than 50 percent of the surface area of the potato | When its severity causes a wrinkling of the skin over more than 50 percent of the surface. | Sprouts | When more than 5 percent of the potatoes in any lot have any sprout more than 1/4 inch in length at shipping point; more than 1/2 inch in length at destination; or have numerous individual and/or clusters of sprouts which materially detract from the appearance of the potato | When more than 10 percent of the potatoes in any lot have any sprout more than 1/2 inch in length at shipping point; more than 1 inch in length at destination; or have numerous individual and/or clusters of sprouts which seriously detract from the appearance of the potato. Serious damage by sprouts shall only be scored against the U.S. Commercial and U.S. No. 2 grades. | Sunburn | When removal causes loss of more than 5 percent of total weight of potato | When removal causes loss more than 10 percent of total weight of potato. | Sunken Discolored Areas | SEE TABLE VI | SEE TABLE VI. | Surface Cracks (Areas affected by fine net-like cracking should be ignored.) | When smooth shallow cracking affects more than 1/3 of the surface or when rough deep cracking affects more than 5 percent of the surface | When rough deep cracking affects more than 10 percent of the surface. | Wireworm or Grass Damage | When affecting the flesh of the potato and removal causes loss of more than 5 percent of total weight of potato. | When affecting the flesh of the potato and removal causes loss of more than 10 percent of total weight of potato. |
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The following defects are considered serious damage when present in any degree: 1. Freezing. 2. Late blight. 3. Ring rot. 4. Southern bacterial wilt. 5. Soft rot. 6. Wet breakdown.
Table IV—Flattened or Depressed Areas—Pressure Bruises Maximum Area Allowed
| Diameter | Weight | No. 1
(aggregate area) | No. 2
(aggregate area) | Potato is: | Potato is: | Not more than: | Not more than: | Less than 2 in | Less than 4 oz | 1/2 in | 1 in | 2 to 2 1/2 in | 4 to 6 oz | 1 in | 1 1/2 in | More than 2 1/2 to 3 in | More than 6 to 8 oz | 1 1/4 in | 1 3/4 in | More than 3 to 3 1/2 in | More than 8 to 14 oz | 1 1/2 in | 1 7/8 in | More than 3 1/2 to 4 in | More than 14 to 20 oz | 1 3/4 in | 2 in | More than 4 to 4 1/2 in | More than 20 to 28 oz | 2 in | 2 1/4 in | More than 4 1/2 to 5 in | More than 28 to 36 oz | 2 1/4 in | 2 3/4 in | More than 5 in | More than 36 oz | 2 1/2 in | 3 1/4 in |
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Table V—Depth Allowed for Growth Cracks
| Diameter | Weight | No. 1
(depth) | No. 2
(depth) | Potato is: | Potato is: | Not more than: | Not more than: | Less than 2 in | Less than 4 oz | 1/8 in | 1/4 in | 2 to 2 1/2 in | 4 oz to 6 oz | 1/4 in | 3/8 in | More than 2 1/2 to 3 in | More than 6 oz to 8 oz | 3/8 in | 1/2 in | More than 3 in | More than 8 oz | 1/2 in | 5/8 in |
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Table VI—Sunken Discolored Areas Maximum Area Allowed
| Diameter | Weight | No. 1
(aggregate area) | No. 2
(aggregate area) | Potato is: | Potato is: | Not more than: | Not more than: | Less than 2 in | Less than 4 oz | 3/8 in | 3/4 in | 2 to 2 1/2 in | 4 to 6 oz | 3/4 in | 1 in | More than 2 1/2 to 3 in | More than 6 to 8 oz | 1 in | 1 1/4 in | More than 3 to 3 1/2 in | More than 8 to 14 oz | 1 1/4 in | 1 1/2 in | More than 3 1/2 to 4 in | More than 14 to 20 oz | 1 1/2 in | 1 3/4 in | More than 4 to 4 1/2 in | More than 20 to 28 oz | 1 3/4 in | 2 in | More than 4 1/2 to 5 in | More than 28 to 36 oz | 2 in | 2 1/4 in | More than 5 in | More than 36 oz | 2 1/4 in | 2 1/2 in |
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