§ 201.52 7 CFR Ch. I (1–1–13 Edition) § 201.52 Noxious-weed seeds. (c) When only a germination test is (a) The determination of the number required and the pure seed is found to of seeds, bulblets, or tubers of indi- be less than 98 percent, the seed for the vidual noxious weeds present per unit test shall be obtained by separating the weight should be made on at least the sample into two components as follows: minimum quantities listed in § 201.46 (1) Pure seed and (2) other crop seed, Table 1: Provided, That if the following weed seed, and inert matter. In making 1 indicated numbers of a single kind of this separation at least ⁄4 of the quan- seed, bulblet, or tuber are found in the tity required for a regular purity anal- pure seed analysis (or noxious-weed ysis shall be used. The whole sample seed examination of a like amount) the must be well mixed and divided in such occurrence of that kind in the remain- a manner as to get a completely rep- der of the bulk examined for noxious- resentative subsample. weed seeds need not be noted: 1⁄2-gram [10 FR 9952, Aug. 11, 1945, as amended at 20 purity working sample, 16 or more FR 7931, Oct. 21, 1955] seeds; 1-gram purity working sample, 23 or more seeds; 2-gram purity work- § 201.54 Number of seeds for germina- ing sample or larger, 30 or more seeds. tion. The seeds per unit weight shall be At least 400 seeds shall be tested for based on the number of single seeds. germination; except that in mixtures, The number of individual seeds shall be 200 seeds of each of those kinds present determined in burs of sandbur to the extent of 15 percent or less may (Cenchrus spp.) and cocklebur be used in lieu of 400, in which case an (Xanthium spp.); in capsules of dodder additional 2 percent is to be added to (Cuscuta spp.); in berries of the regular germination tolerances. groundcherry, horsenettle, and The seeds shall be tested in replicate nightshade (Solanaceae); and in the tests of 100 seeds or less. fruits of other noxious weeds that con- tain more than one seed. Refer to [59 FR 64500, Dec. 14, 1994] §§ 201.50 and 201.51(b)(4) for the classi- § 201.55 Retests. fication of weed seeds and inert matter, respectively. Retests shall be made as follows: (b) A noxious-weed seed examination (a) When the range of 100-seed rep- of coated seed samples shall be made licates of a given test exceeds the max- by examining approximately 25,000 imum tolerated range in the table ap- units obtained in accordance with pearing in this section. § 201.46(d) and which have been de-coat- TABLE OF MAXIMUM TOLERATED RANGES BE- ed by the method described in TWEEN 100-SEED REPLICATES FOR USE IN § 201.51b(c). CONNECTION WITH § 201.55(A) [59 FR 64499, Dec. 14, 1994] Average percent germinations Maximum allowed between replicates GERMINATION TESTS IN THE ADMINISTRATION OF THE ACT 4 2 replicates replicates § 201.53 Source of seeds for germina- 99 ............................... 2 5 tion. 98 ............................... 3 6 (a) When both purity and germina- 97 ............................... 4 7 6 96 ............................... 5 8 6 tion tests are required, seeds for germi- 95 ............................... 6 9 7 nation shall be taken from the separa- 94 ............................... 7 10 8 tion of the kind, variety, or type con- 93 ............................... 8 10 8 92 ............................... 9 11 9 sidered pure seed and shall be counted 91 ............................... 10 11 9 without discrimination as to size or ap- 90 ............................... 11 12 9 pearance. 89 ............................... 12 12 10 (b) When only a germination test is 88 ............................... 13 13 10 87 ............................... 14 13 11 required and the pure seed is estimated 86 ............................... 15 14 11 or determined to be at least 98 percent, 85 ............................... 16 14 11 the pure seed for the germination test 84 ............................... 17 14 11 83 ............................... 18 15 12 may be taken indiscriminately from a 82 ............................... 19 15 12 representative portion of the bulk. 81 ............................... 20 15 12 344 VerDate Mar<15>2010 21:35 Jan 25, 2013 Jkt 229054 PO 00000 Frm 00354 Fmt 8010 Sfmt 8010 Q:\07\7V3.TXT ofr150 PsN: PC150 Agricultural Marketing Service, USDA § 201.55a TABLE OF MAXIMUM TOLERATED RANGES BE- licates do not exceed the corresponding val- TWEEN 100-SEED REPLICATES FOR USE IN ues found in the ‘‘4 replicates’’ column, no CONNECTION WITH § 201.55(A)—Continued additional testing is required. However, if the differences exceed the values in the ‘‘4 Average percent germinations Maximum allowed replicates’’ column, retesting is necessary. between replicates [25 FR 8771, Sept. 13, 1960, as amended at 65 4 2 FR 1707, Jan. 11, 2000] replicates replicates 80 ............................... 21 16 13 § 201.55a Moisture and aeration of sub- 79 ............................... 22 16 13 stratum. 78 ............................... 23 16 13 77 ............................... 24 17 13 (a) The substratum must be moist 76 ............................... 25 17 13 enough to supply the needed moisture 75 ............................... 26 17 14 to the seeds at all times. Excessive 74 ............................... 27 17 14 73 ............................... 28 17 14 moisture which will restrict aeration 72 ............................... 29 18 14 of the seeds should be avoided. Except 71 ............................... 30 18 14 as provided for those kinds of seeds re- 70 ............................... 31 18 14 69 ............................... 32 18 14 quiring high moisture levels of the ger- 68 ............................... 33 18 15 mination media, the substrata should 67 ............................... 34 18 15 never be so wet that a film of water is 66 ............................... 35 19 15 65 ............................... 36 19 15 formed around the seeds. For most 64 ............................... 37 19 15 kinds of seeds blotters or other paper 63 ............................... 38 19 15 substrata should not be so wet that by 62 ............................... 38 19 15 pressing, a film of water forms around 61 ............................... 40 19 15 60 ............................... 41 19 15 the finger. 59 ............................... 42 19 15 (b) The following formula may be 58 ............................... 43 19 15 used as a guide in the preparation of 57 ............................... 44 19 15 56 ............................... 45 19 15 sand for germination tests: 55 ............................... 46 20 15 54 ............................... 47 20 16 [118.3 CC. (1 GILL) SAND/ITS WEIGHT IN 53 ............................... 48 20 16 GRAMS]×20.2¥8.0=THE NUMBER OF CC. 52 ............................... 48 20 16 51 ............................... 50 20 16 OF WATER TO ADD TO EACH 100 GRAMS OF AIR-DRY SAND. (b) When at the time of the pre- scribed final count there are indica- (c) The amount of water provided by tions, such as presence of firm this formula is satisfactory for seeds ungerminated seeds, that a satisfac- the size of clovers and will have to be tory germination has not been ob- modified slightly, depending on the tained; kind of seed being tested and the kind (c) When there is evidence that the of sand used. For example, slightly results may not be reliable due to im- more moisture should be added when proper test conditions, errors in seed- the larger seeds are to be tested. ling evaluation, the presence of fungi (d) In preparing soil tests water or bacteria, or inaccuracies in counting should be added to the soil until it can or recording results; be formed into a ball when squeezed in (d) When a sample shows seedling in- the palm of the hand but will break jury or abnormality as a result of freely when pressed between two fin- chemical treatment, of exposure to gers. After the soil has been moistened chemicals, or of toxicity from any it should be rubbed through a sieve and source. (Retest shall be made in soil or put in the seed containers without a mixture of soil and sand); packing. (e) When no two satisfactory tests (e) The addition of water subsequent are within tolerance. to placing the seed in test will depend on the evaporation from the substrata NOTE TO § 201.55: To find the maximum tol- in the germination chambers. Since the erated range, compute the average percent- rate of evaporation will depend upon age of all 100 seed replicates of a given test, rounding off the result to the nearest whole the relative humidity of the air, it is number. The germination is found in the desirable to keep water in the germina- first two columns of the table. When the dif- tion chambers or to provide other ferences between highest and lowest rep- means of supplying a relative humidity 345 VerDate Mar<15>2010 21:35 Jan 25, 2013 Jkt 229054 PO 00000 Frm 00355 Fmt 8010 Sfmt 8010 Q:\07\7V3.TXT ofr150 PsN: PC150 § 201.56 7 CFR Ch. I (1–1–13 Edition) of approximately 95 percent. Germina- the usual first count and the final tion tests should be observed at fre- count. During the progress of the ger- quent intervals to insure an adequate mination test, seeds which are obvi- moisture supply of the substrata at all ously dead and moldy and which may times. be a source of contamination of [20 FR 7931, Oct. 21, 1955] healthy seeds should be removed at each count and the number of such § 201.56 Interpretation. dead seeds should be recorded. When symptoms of certain diseases develop (a) A seed shall be considered to have germinated when it has developed which can be readily recognized and those essential structures which, for identified, their presence should be the kind of seed under consideration, noted. are indicative of its ability to produce (d) Seed units containing more than a normal plant under favorable condi- one seed or embryo, such as New Zea- tions.