7 CFR 51.1541 – U.S. No. 1
“U.S. No. 1” consists of potatoes which meet the following requirements:
(a) Similar varietal characteristics, except when designated as a mixed or specialty pack;
(b) Firm;
(c) Fairly clean;
(d) Fairly well shaped;
(e) Free from:
(1) Freezing;
(2) Blackheart;
(3) Late blight, southern bacterial wilt and ring rot; and,
(4) Soft rot and wet breakdown.
(f) Free from damage by any other cause. See §§ 51.1564 and 51.1565.
(g) Size. Not less than 1
(h) For tolerances see § 51.1546.