U.S. Grade AA shall consist of stalks of celery of similar varietal characteristics, which are well developed, and have good heart formation; which are clean, well trimmed, fairly compact, and are free from blackheart, brown stem, decay (except dry type crater rot), doubles, and from damage caused by crater rot, wilting, cutworms, freezing, suckers, growth cracks, hollow crown, pithy branches, seedstems, rust, cracked stem, other diseases, insects or mechanical or other means.
The average midrib length of the outer whorl of branches on stalks in this grade shall be not less than 7 inches. (See §§ 51.599 and 51.600.)
Incident to proper grading and handling other than for average midrib length of branches not more than 5 percent, by count, of the stalks in any lot may fail to meet the requirements of the grade including not more than 1 percent for stalks affected by moist type decay. In addition, not more than 3 percent, by count, of the stalks in any lot may fail to meet the requirements as to average midrib length of the stalks.