§201.46. Weight of working sample. — Inbound Citations

(b) Each sample of agricultural seed retained shall be at least the weight required for a noxious-weed seed examination as set forth in § 201.46 and each sample of vegetable seed retained shall consist of at least 400 seeds. The record shall be kept in such manner as to permit comparison with the records required to be kept by other persons for the same lot of seed so that the origin, treatment (including, but not limited to, coating, film coating, encrusting, or pelleting), germination, and purity (including variety) of agricultural seed and the treatment (including, but not limited to, coating, film coating, encrusting, or pelleting), germination and variety of vegetable seed may be traced from the grower to the ultimate consumer and so that the lot of seed may be correctly labeled. The record shall be accessible for inspection by the authorized agents of the Secretary for purposes of the effective administration of the Act at any time during customary business hours.

(a) The determination of the number of seeds, bulblets, or tubers of individual noxious weeds present per unit weight should be made on at least the minimum quantities listed in § 201.46 Table 1: Provided, That if the following indicated numbers of a single kind of seed, bulblet, or tuber are found in the pure seed analysis (or noxious-weed seed examination of a like amount) the occurrence of that kind in the remainder of the bulk examined for noxious-weed seeds need not be noted: 1/2-gram purity working sample, 16 or more seeds; 1-gram purity working sample, 23 or more seeds; 2-gram purity working sample or larger, 30 or more seeds. The seeds per unit weight shall be based on the number of single seeds. The number of individual seeds shall be determined in burs of sandbur (Cenchrus spp.) and cocklebur (Xanthium spp.); in capsules of dodder (Cuscuta spp.); in berries of groundcherry, horsenettle, and nightshade (Solanaceae); and in the fruits of other noxious weeds that contain more than one seed. Refer to §§ 201.50 and 201.51(b)(4) for the classification of weed seeds and inert matter, respectively.

(2) Values for H and L shall be obtained from the last column of table 1, § 201.46, or by laboratory tests for inert matter, weed seeds, or other crop seeds where such values are not obtainable from table 1. In computing tolerances for nonchaffy kinds the values for T1 are taken from column C of table 3, and for chaffy kinds the values for T1 are taken from column D of table 3.

Tolerances for rates of occurrence of noxious-weed seeds shall be recognized and shall be applied to the number of noxious-weed seeds found by analysis in the quantity of seed specified for noxious-weed seed determinations in § 201.46, except as provided in § 201.16(b). Rates per pound or ounce must be converted to the equivalent number of seeds found in § 201.46, Table 1, Minimum weight for noxious-weed seed examination (grams). Some tolerances are listed in the following table. The number found as represented by the label or test (Column X) will be considered within tolerance if not more than the corresponding numbers in Column Y are found by analysis in the administration of the Act. For numbers of seed greater than those in the table, a tolerance based on a degree of certainty of 5 percent (P = 0.05) can be calculated by the formula, Y = X + 1.65√X + 0.03, where X is the number of seeds represented by the label or test and Y is the maximum number within tolerance.

(a) The working sample for coated seed is obtained as described in § 201.46(d) (1) and (2), and weighed in grams to four significant figures.

(b) A noxious-weed seed examination of coated seed samples shall be made by examining approximately 25,000 units obtained in accordance with § 201.46(d) and which have been de-coated by the method described in § 201.51b(c).