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;
(c) Fairly clean; 2
(d) Fairly well shaped;
(e) Free from:
(3) Late blight, southern bacterial wilt and ring rot; and,
(h) For tolerances see § 51.1546.
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