“U.S. No. 1” consists of potatoes which meet the following requirements:

1. (a) Similar varietal characteristics, except when designated as a mixed or specialty pack;
2. (b) Firm;
3. (c) Fairly clean; ²
4. (d) Fairly well shaped;

5. (e) Free from:

   1. (1) Freezing;
   2. (2) Blackheart;
   3. (3) Late blight, southern bacterial wilt and ring rot; and,
   4. (4) Soft rot and wet breakdown.
6. (f) Free from damage by any other cause. See §§ 51.1564 and 51.1565.
7. (g) Size. Not less than 1 7/8 inches in diameter, unless otherwise specified in connection with the grade.
8. (h) For tolerances see § 51.1546.

² Potatoes in containers bearing official State Seed Certification Tags and Seals are not required to be fairly clean but shall be free from damage by dirt.

[35 FR 18258, Dec. 1, 1970, as amended at 76 FR 31789, June 2, 2011]