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calculation shall be regarded as pure seed and the remainder of the weight of multiple units shall be regarded as inert matter. (If the multiple units constitute less than 5 percent of the sample, these special procedures do not apply and the units are separated manually into pure seed and inert matter.)
(c) With exception of chewings fescue, these methods are not applicable to the kinds listed when they occur in mixtures of kinds. [25 F.R. 8771, Sept. 18, 1960, as amended at 30 F.R. 7891, June 18, 1965) § 201.52 Noxious-weed seeds.
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 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 species in the remainder of the bulk examined for noxious-weed seeds need not be noted: 12-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. If the sample contains seed-bearing fruits or other seed-bearing structures of noxious weeds, such as burs of Cenchrus, capsules of Cuscuta or berries of Solanum, the number of individual seeds shall be determined. [20 F.R. 7931, Oct. 21, 1955, as amended at 25 F.R. 8771, Sept. 13, 1960)
shall be obtained by separating the sample into two components as follows: (1) Pure seed and (2) other crop seed, weed seed, and inert matter. In making this separation at least 44 of the quan. tity required for a regular purity analysis shall be used. The whole sample must be well mixed and divided in such a manner as to get a completely representative subsample. (10 F.R. 9952, Aug. 11, 1945, as amended at 20 F.R. 7931, Oct. 21, 1955) $ 201.54 Number of seeds for germina
tion. At least 400 seeds shall be tested for germination except that in mixtures 200 seeds of each of those kinds present to the extent of 15 percent or less may be used in lieu of 400, in which case an additional 2 percent is to be added to the regular germination tolerances. The seeds shall be tested in replicate tests of 100 seeds or less. (15 FR. 2395, Apr. 28, 1950) $ 201.55 Retests.
Retests shall be made as follows:
(a) When the range of 100-seed replicates of a given test exceeds the maximum tolerated range in the table appearing in this section. TABLE OF MAXIMUM TOLERATED RANGES BE
TWEEN 100-SEED REPLICATES FOR USE IN
GERMINATION TESTS IN THE ADMINISTRA
TION OF THE ACT
8 201.53 Source of seeds for germina
tion. (a) When both purity and germination tests are required, seeds for germination shall be taken from the separation of the kind, variety, or type considered pure seed and shall be counted without discrimination as to size or appearance.
(b) When only a germination test is required and the pure seed is estimated or determined to be at least 98 percent, the pure seed for the germination test may be taken indiscriminately from a representative portion of the bulk.
(c) When only a germination test is required and the pure seed is found to be less than 98 percent, the seed for the test
96. 95 94. 93. 92. 91. 90. 89. 88 87. 86. 85.. 84. 83. 82 81 80.. 79. 78. 77. 76. 75. 74. 73. 72.
7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22
10 10 11 11 12 12 13 13 14 14 14 15 15 15 16 16 16 17 17 17 17 17 18
10 10 11 11 12 12 13 13 13 14 14 14 15 15 15 15 16 16 16 16 16
10 10 11 11 11 11 12 12 12 13 13 13 13 13 14 14 14 14
EXPLANATORY NOTE: To find the maximum tolerated range, compute the average percentage of all 100-seed replicates of a given test, rounding off the result to the nearest whole number. The germination is found in the first two columns of the table. When the differences between highest and lowest replicates do not exceed the corresponding values found in the "4-replicate" column, no additional testing is required. If the differences exceed these values, omit the lowest replicate and compute the average of the three remaining replicates. If the range between the highest and lowest three replicates do not exceed the values in the "g-replicate" column for the new average percentage germination, retesting is not required and the Average of the three replicates shall be regarded as the percentage germination. How. ever, it the diferences exceed the values in the "g-replicate" column, retesting 18 necessary
when only 200 seeds are tested, retest 1 the range of the two replicates exceeds the values in the “2-replicate” column. In order to form 100-seed replicates, combine subreplicates of 25 or 50 seeds which were closest together in the germinator. (25 P.R. 8771, Sept. 18, 1960] 8 201.55a Moisture and aeration of sub
stratun. (a) The substratum must be moist enough to supply the needed moisture to the seeds at all times. Excessive moisture which will restrict aeration of the seeds should be avoided. Except as provided for those kinds of seeds requiring high moisture levels of the germination media, the substrata should never be so wet that a film of water is formed around tee seeds. For most kinds of seeds blotters or other paper substrata should not be so wet that by pressing, & ilm of water forms around the finger.
(b) The following formula may be used as a guide in the preparation of sand for germination tests:
(b) When at the time of the prescribed final count there are indications, such as presence of firm ungerminated seeds, that a satisfactory germination has not been obtained;
(c) When there is evidence that the results may not be reliable due to improper test conditions, errors in seedling evaluation, the presence of fungi or bacteria, or inaccuracies in counting or recording results;
(d) When & sample shows seedling injury or abnormality as a result of chemical treatment, of exposure to chemicals, or of toxicity from any source. (Retest shall be made in soil or a mixture of soil and sand);
(e) When no two satisfactory tests are within tolerance.
118.3 cc. (1 gill) sand X 20.2-8.0=The number of cc. of water to add to each 100 grams Its weight in grams
of air-dry sand.
(c) The amount of water provided by this formula is satisfactory for seeds the size of clovers and will have to be modified slightly, depending on the kind of seed being tested and the kind of sand used. For example, slightly more moisture should be added when the larger seeds are to be tested.
(d) In · preparing soll tests water should be added to the soll until it can be formed into a ball when squeezed in the palm of the hand but will break freely when pressed between two fingers.
After the soil has been moistened it should be rubbed through a sieve and put in the seed containers without packing.
(e) The addition of water subsequent to placing the seed in test will depend on the evaporation from the substrata in the germination chambers. Since the rate of evaporation will depend upon the relative humidity of the air, it is desirable to keep water in the germination chambers or to provide other means of supplying a relative humidity of approximately 95 percent. Germination tests
= should be observed at frequent intervals
to insure an adequate moisture supply
(a) A seed shall be considered to bave germinated when it has developed those essential structures which, for the kind of seed under consideration, are indicative of its ability to produce a normal plant under favorable conditions. Seedlings possessing those essential structures are referred to as normal seedlings. Abnormal seedlings, consisting of those which are broken, devoid of roots, malformed, or weak, and other types not possessing essential structures, shall not be considered to have germinated.
(b) Sand and/or soil tests may be used as a guide in determining the classification of questionable seedlings and the evaluation of germination tests made on approved artificial media. This is intended to provide a method of checking the reliability of tests made on artiticial substrata when there may be doubt as to the proper evaluation of such tests.
(c) Seedlings infected with fungi or bacteria should be regarded as normal if all essential structures are present. A seedling that has been seriously damaged by bacteria or fungi from any source other than the specific seed should be regarded as normal if it is determined that all essential structures were present before the injury or damage occurred. Germination counts should be made on samples where contamination and decay are present at approximately 2-day intervals between the usual first count and the final count. During the progress of the germination test, seeds which are obviously dead and moldy and which may be a source of contamination of healthy seeds should be removed at each count and the number of such dead seeds should be recorded. When symptoms of certain diseases develop which can be readily recognized and identified, their presence should be noted.
(d) Seed units containing more than one seed or embryo, such as New Zealand spinach seed, Beta seed, double fruits of the carrot family (Umbelliferae), multiple seeds of burnet, and seed units of grasses consisting of multiple florets, shall be tested as a single seed and shall be regarded as having germinated if they produce one or more normal seedlings.
(e) Standard guides for seedling interpretation shall include the photographs of normal and abnormal seedlings i identified by photo numbers in table 2 in § 201.58 and the following descriptions for specific kinds and groups. (20 F.R. 7931, Oct. 21, 1955, as amended at 25 F.R. 8771, Sept. 13, 1960) & 201.56-1 Goosefoot family (Cheno
podiaceae) and Carpet weed family
(Aizoaceae). (a) Kinds of seed: Beet, swiss chard, mangel, spinach, and New Zealand spinach.
(b) A completely normal seedling of the kinds specified in paragraph (a) of this section should have a long, slender root with root hairs, a long, welldeveloped hypocotyl, two attached leaflike cotyledons and an intact but small epicotyl. Normal seedlings shall include those that have: (1) A well-developed, long, slender root with root hairs; (2) a stubby primary root provided the secondary roots are strong and the hypocotyl is near normal length, as in spinach; (3) at least one attached cotyledon, provided the seedling is otherwise normal; (4) slight infection by fungi. provided none of the essential seedling structures have been damaged; (5) normal seedling structures of Beta that have been discolored from toxic substances in the seed balls or other causes; or (6) at least one normal seedling from a seed ball, regardless of whether abnormal seedlings also emerge from the same fruit.
(c) Abnormal seedlings include those that have: (1) No root or a stubby primary root with poor secondary root development, usually associated with a shortened hypocotyl; (2) a malformed, shortened, twisted, watery, or stubby hypocotyl; usually associated with a stubby root but not necessarily so; (3) deep grainy lesions or cracks in the hypocotyl if they appear to interfere with the conducting tissues; (4) both cotyledons absent in samples of “sheared” beets and occasional samples of spinach; (5) two large cotyledons, but a malformed, short hypocotyl, usually with a stubby root; (6) decayed cotyledons or hypocotyl, provided they are not the result of improper test conditions (if there is decay of beet seed
1 These photographs may be purchased from the Office of Information, United States Department of Agriculture, Washington, D.C. 20250.
lings in blotter tests the results from a length); and (iv) an epicotyl entirely properly conducted soil or sand test free of injury. should be accepted as correct); or (7) (2) Abnormal seedlings include those various combinations of the abnormali- that have: (i) No roots, or roots clearly ties described in this paragraph.
less than half normal length with root [20 F. R. 7932, Oct. 21, 1955)
tips biunt, swollen, or discolored; (ii)
hypocotyls clearly less than half normal & 201.56-2 Sunflower family (Composi
length, or severely twisted or grainy, or tae).
with cracks or lesions extending into the Kinds of seed: Artichoke, cardoon, central conducting tissue; (iii) only one chicory, dandelion, endive, great burdock, cotyledon, or cotyledons with half or lettuce, saflower, salisfy, and sunflower. more than half their total area necrotic By the end of the germination test, a or injured (the hypocotyl and root are perfectly normal seedling belonging to usually less than half normal length), or the sunflower family should have a well- swollen cotyledons (usually grayish or developed root with root hairs, & long darkened) with extremely short or vesand well-developed hypocotyl, two leaf- tigial hypocotyl and root (see coat uslike cotyledons, and a small but visible ually adhering to cotyledons); (iv) no epicotyl.
epicotyl or an epicotyl with any degree of (a) Lettuce: The interpretations of injury or physiological necrosis. lettuce seedlings are made only at the (b) Other kinds in the sunflower end of the test period. When used to family: This group includes artichoke, describe seedling structures "normal cardoon, sunflower, safflower, salsify, length" means that length attained by dandelion, chicory, endive, and great a vigorous sample of the same variety
burdock. of lettuce as the one being tested when (1) Normal seedlings include those both are placed under the same test con
that have: (1) A well-developed, long, ditions. Physiological necrosis of cotyle- Slender primary root with root hairs; dons is frequently manifested by soft- (ii) a stubby root if there are one or ened, grayish, blackish, or reddish areas more strong secondary roots, provided and should not be confused with natural the seedling is otherwise normal; (iii) pigmentation. Seedlings with extensive a well-developed, long hypocotyl with physiological necrosis and/or injured no prominent breaks or deep lesions areas on the cotyledons are slower in which might interfere with the conductgrowth and tend to be shorter than seed- Ing tissues; (iv) one complete cotyledon lings without such damage. It is not nec- or two broken cotyledons with half or essary to distinguish between necrotic more original cotyledon tissue remainareas and injury caused by fungi and ing attached to the seedling (epicotyl bacteria since the interpretation is the must be present); or (v) slight Infection same for all conditions. Seedlings in- of the roots or hypocotyl with fungi, terpretations are to be made with not provided none of the essential seeding more than a 7 x magnification. Colored structures have been damaged. photographs of lettuce cotyledons are to
(2) Abnormal seedlings include those be used as guides for classification. These that have: (i) No root or a stubby root photographs may be obtained from the with weak secondary roots, usually assoU.S. Department of Agriculture, Agri- ciated with a shortened hypocotyl: (ii) cultural Marketing Service, Grain Di- a malformed hypocotyl, which may be vision, Seed Branch, South Laboratory curled, shortened, or thickened, usually Building, Agricultural Research Center, associated with a stubby root; (iii) deep, Beltsville, Md. 20705.
unhealed cracks or grainy areas on the (1) Normal seedlings include those hypocotyl, extending into the conductthat have: (i) Long, vigorous roots, over ing tissues; (iv) both cotyledons entirely half the usual length for vigorous seed
broken off ; (v) part of one cotyledon or lings; (ii) long, vigorous hypocotyls, over
two broken cotyledons with less than hall half the usual length for vigorous seed
of the original cotyledon tissue remainlings, with no cracks or lesions extending into the central conducting tissue; (iii)
ing attached; (yi) two normal cotyledons two cotyledons either free of injury or
with a short malformed hyopcotyl, usuwith less than half the total cotyledon
ally with a stubby root; (vil) decayed surface covered by physiological necrosis cotyledons, provided the infection is not or injured areas (the hypocotyl and root caused by improper test conditions; should be more than half normal (viii) epicotyl absent; or (ix) various
combinations of the abnormalities de- of the seedlings) provided this condition scribed.
is not caused by excessive moisture of the [20 FR 7932, Oct. 21, 1955, as amended at substratum; or (ix) various combina26 FR 10035, Oct. 26, 1961, 30 FR 7891, tions of the abnormalities described in June 18, 1965; 32 FR 12780, Sept. 6, 1967; this subparagraph. 38 FR 12731, May 15, 1973]
(b) Garden cress, upland cress, and 201.56.-3 Mustard family (Crucise
water cress. (1) Normal seedlings inrae).
clude those that have: (i) A wellKinds of seed: Broccoli, brussels
developed, slender root with root hairs;
(ii) a long, well-developed hypocotyl with sprouts, cabbage, Chinese cabbage, caulifiower, collards, garden cress, upland
no prominent breaks or deep lesions
which might interfere with the conductcress, water cress, kale, Chinese kale,
ing tissues; (iii) intact cotyledons; or Siberian kale, kohlrabi, mustard, pak
(iv) slight infection with fungi, provided choi, radish, rape, rutabaga, and turnip.
none of the essential seedling structures By the end of the germination test, a
have been damaged. perfectly normal cruciferous seedling should have a well-developed root, usu
(b) Abnormal seedlings include those
that have: (i) No root, or a stubbly root, ally with root hairs, a long hypocotyl
usually associated with a shortened two intact green leaflike cotyledone and a small but visible epicotyl or growing
hypocotyl; (ii) a malformed hypocotyl,
which may be curled, twisted, shortened, point.
or thickened and frequently associated (a) Radish and Brassica. (1) Nor
with a stubby root; (iii) deep, unhealed mal seedlings include those that have:
cracks or grainy lesions on the hypo(i) A well-developed, long, slender pri
cotyl, extending into the conducting mary root with root hairs; (ii) a well
tissues; (iv) watery hypocotyls, usually developed, long hypocotyl with no promi
associated with stubby roots or decayed nent breaks or deep lesions which might
cotyledons; (v) cotyledons entirely interfere with the conducting tissues;
broken off; (vi) decayed cotyledon, (iii) one or two cotyledons not decayed
provided the infection was not caused at the point of attachment to the hypo
by improper test conditions; or (vii) cotyl, provided the epicotyl is also pres
various combinations of the abnormalient; (iv) slight decay at the base of one
ties described in this subparagraph. cotyledon, provided the epicotyl is not infected; (v) less than 50 percent of the
[20 FR 7932, Oct. 21, 1955, as amended at
25 FR 8772, Sept. 13, 1960, 28 FR 5361, area of the cotyledons covered with spots
May 30, 1963] or darkened areas; or (vi) slight infection of roots or hypocotyl with fungi,
8 201.56-4 Cucurbit family (Cucurbitaprovided none of the essential seedling ceae). structures have been damaged.
(a) Kinds of seed: Citron, cucumber, (2) Abnormal seedlings include those muskmelon or cantaloup, pumpkin, that have: (i) No root or a stubby root, squash, and watermelon. usually associated with a shortened
(b) By the end of the germination hypocotyl; (ii) a malformed hypocotyl, test a perfectly normal seedling should which may be curled, shortened, or have a well-developed primary root with thickened and usually associated with a several secondary roots, a long hypostubby root; (iii) deep, unhealed cracks cotyl, two intact cotyledons, and an epior lesions (often grainy) on the hypo- cotyl or terminal growing bud. cotyl, extending into the conducting (1) Normal seedlings include those tissues; (iv) decay at the point of at
that have: (i) A well-developed primary tachment of both cotyledons to the root with or without secondary roots; hypocotyl which may or may not involve (ii) a stubby primary root with at least the terminal bud; (v) decay at the point two strong and vigorous adventitious of attachment of one cotyledon to the roots, provided the hypocotyl is not hypocotyl, provided the terminal bud is shortened very much; (iii) a long wellalso decayed; (vi) 50 percent or more of developed hypocotyl; (iv) two intact the area of the cotyledons covered with cotyledons; or (V) slight infection by spots or darkened areas; (vii) decayed fungi, provided none of the essential roots or hypocotyl provided the infection seedling structures have been damaged. was not caused by improper test condi- (2) Abnormal seedlings include those tions; (viii) watery hypocotyl (usually that have: (i) No primary root, a stubby associated with some other abnormality primary root only, or a stubby primar