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. 13, 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: 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. 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 FR. 7931, Oct. 21, 1955, as amended at 25 F.R. 8771, Sept. 13, 1960]

GERMINATION TESTS IN THE ADMINISTRATION OF THE ACT

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 1/4 of the quantity 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 FR. 7931, Oct. 21, 1955]

§ 201.54 Number of seeds for germination.

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]

Average percent germinations

Source of seeds for germina

99

5

98

5

97.

6

96.

95

8

94

10

9

93..

8

10

9

92.

(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 a 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 Its weight in grams

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 "8-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. However, if the differences exceed the values in the "3-replicate" column, retesting is necessary.

When only 200 seeds are tested, retest if 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 F.R. 8771, Sept. 18, 1960]

§ 201.55a Moisture and aeration of sub

stratum.

(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 the seeds. For most kinds of seeds blotters or other paper substrata should not be so wet that by pressing, a film of water forms around the finger.

(b) The following formula may be used as a guide in the preparation of sand for germination tests:

(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 soil tests water should be added to the soil 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 of the substrata at all times.

[20 F. R. 7981, Oct. 21, 1955]

§ 201.56 Interpretation.

(a) A seed shall be considered to have 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 artificial 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.

1

(e) Standard guides for seedling interpretation shall include the photographs of normal and abnormal seedlings 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 (Chenopodiaceae) and Carpetweed 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

as

1 These photographs may be purchased from the Office of Information, United States Department of Agriculture, Washington, D.C. 20250.

Kinds of seed: Artichoke, cardoon, chicory, dandelion, endive, great burdock, lettuce, safflower, salisfy, and sunflower. By the end of the germination test, a perfectly normal seedling belonging to the sunflower family should have a welldeveloped root with root hairs, a long and well-developed hypocotyl, two leaflike cotyledons, and a small but visible epicotyl.

(a) Lettuce: The interpretations of lettuce seedlings are made only at the end of the test period. When used to describe seedling structures "normal length" means that length attained by a vigorous sample of the same variety of lettuce as the one being tested when both are placed under the same test conditions. Physiological necrosis of cotyledons is frequently manifested by softened, grayish, blackish, or reddish areas and should not be confused with natural pigmentation. Seedlings with extensive physiological necrosis and/or injured areas on the cotyledons are slower in growth and tend to be shorter than seedlings without such damage. It is not necessary to distinguish between necrotic areas and injury caused by fungi and bacteria since the interpretation is the same for all conditions. Seedlings interpretations are to be made with not more than a 7 × magnification. Colored photographs of lettuce cotyledons are to be used as guides for classification. These photographs may be obtained from the U.S. Department of Agriculture, Agricultural Marketing Service, Grain Division, Seed Branch, South Laboratory Building, Agricultural Research Center, Beltsville, Md. 20705.

(1) Normal seedlings include those that have: (i) Long, vigorous roots, over half the usual length for vigorous seedlings; (ii) long, vigorous hypocotyls, over half the usual length for vigorous seedlings, with no cracks or lesions extending into the central conducting tissue; (iii) two cotyledons either free of injury or with less than half the total cotyledon surface covered by physiological necrosis or injured areas (the hypocotyl and root should be more than half normal

length); and (iv) an epicotyl entirely free of injury.

(2) Abnormal seedlings include those that have: (i) No roots, or roots clearly less than half normal length with root tips blunt, swollen, or discolored; (ii) hypocotyls clearly less than half normal length, or severely twisted or grainy, or with cracks or lesions extending into the central conducting tissue; (iii) only one cotyledon, or cotyledons with half or more than half their total area necrotic or injured (the hypocotyl and root are usually less than half normal length), or swollen cotyledons (usually grayish or darkened) with extremely short or vestigial hypocotyl and root (see coat usually adhering to cotyledons); (iv) no epicotyl or an epicotyl with any degree of injury or physiological necrosis.

(b) Other kinds in the sunflower family: This group includes artichoke, cardoon, sunflower, safflower, salsify, dandelion, chicory, endive, and great burdock.

(1) Normal seedlings include those that have: (i) A well-developed, long, slender primary root with root hairs; (ii) a stubby root if there are one or more strong secondary roots, provided the seedling is otherwise normal; (iii) a well-developed, long hypocotyl with no prominent breaks or deep lesions which might interfere with the conducting tissues; (iv) one complete cotyledon or two broken cotyledons with half or more original cotyledon tissue remaining attached to the seedling (epicotyl must be present); or (v) slight infection of the roots or hypocotyl with fungi, provided none of the essential seeding structures have been damaged.

(2) Abnormal seedlings include those that have: (i) No root or a stubby root with weak secondary roots, usually associated with a shortened hypocotyl; (ii) a malformed hypocotyl, which may be curled, shortened, or thickened, usually associated with a stubby root; (iii) deep. unhealed cracks or grainy areas on the hypocotyl, extending into the conducting tissues; (iv) both cotyledons entirely broken off; (v) part of one cotyledon or two broken cotyledons with less than half of the original cotyledon tissue remaining attached; (vi) two normal cotyledons with a short malformed hyopcotyl, usually with a stubby root; (vi) decayed cotyledons, provided the infection is not caused by improper test conditions; (viii) epicotyl absent; or (ix) various

Kinds of seed: Broccoli, brussels sprouts, cabbage, Chinese cabbage, cauliflower, collards, garden cress, upland cress, water cress, kale, Chinese kale, Siberian kale, kohlrabi, mustard, pakchoi, radish, rape, rutabaga, and turnip. By the end of the germination test, a perfectly normal cruciferous seedling should have a well-developed root, usually with root hairs, a long hypocotyl two intact green leaflike cotyledone and a small but visible epicotyl or growing point.

(a) Radish and Brassica. (1) Normal seedlings include those that have: (1) A well-developed, long, slender primary root with root hairs; (ii) a welldeveloped, long hypocotyl with no prominent breaks or deep lesions which might interfere with the conducting tissues; (iii) one or two cotyledons not decayed at the point of attachment to the hypocotyl, provided the epicotyl is also present; (iv) slight decay at the base of one cotyledon, provided the epicotyl is not infected; (v) less than 50 percent of the area of the cotyledons covered with spots or darkened areas; or (vi) slight infection of roots or hypocotyl with fungi, provided none of the essential seedling structures have been damaged.

(2) Abnormal seedlings include those that have: (i) No root or a stubby root, usually associated with a shortened

hypocotyl; (ii) a malformed hypocotyl, which may be curled, shortened, or thickened and usually associated with a stubby root; (iii) deep, unhealed cracks or lesions (often grainy) on the hypocotyl, extending into the conducting tissues; (iv) decay at the point of attachment of both cotyledons to the hypocotyl which may or may not involve the terminal bud; (v) decay at the point of attachment of one cotyledon to the hypocotyl, provided the terminal bud is also decayed; (vi) 50 percent or more of the area of the cotyledons covered with spots or darkened areas; (vii) decayed roots or hypocotyl provided the infection was not caused by improper test conditions; (viii) watery hypocotyl (usually associated with some other abnormality

of the seedlings) provided this condition is not caused by excessive moisture of the substratum; or (ix) various combinations of the abnormalities described in this subparagraph.

(b) Garden cress, upland cress, and water cress. (1) Normal seedlings include those that have: (i) A welldeveloped, slender root with root hairs; (ii) a long, well-developed hypocotyl with no prominent breaks or deep lesions which might interfere with the conducting tissues; (iii) intact cotyledons; or (iv) slight infection with fungi, provided none of the essential seedling structures have been damaged.

(b) Abnormal seedlings include those that have: (i) No rcot, or a stubbly root, usually associated with a shortened hypocotyl; (ii) a malformed hypocotyl, which may be curled, twisted, shortened, or thickened and frequently associated with a stubby root; (iii) deep, unhealed cracks or grainy lesions on the hypocotyl, extending into the conducting tissues; (iv) watery hypocotyls, usually associated with stubby roots or decayed cotyledons; (v) cotyledons entirely broken off; (vi) decayed cotyledon, provided the infection was not caused by improper test conditions; or (vii) various combinations of the abnormalities described in this subparagraph. [20 FR 7932, Oct. 21, 1955, as amended at 25 FR 8772, Sept. 13, 1960, 28 FR 5361, May 30, 1963]

(a) Kinds of seed: Citron, cucumber, muskmelon or cantaloup, pumpkin, squash, and watermelon.

(b) By the end of the germination test a perfectly normal seedling should have a well-developed primary root with several secondary roots, a long hypocotyl, two intact cotyledons, and an epicotyl or terminal growing bud.

(1) Normal seedlings include those that have: (i) A well-developed primary root with or without secondary roots; (ii) a stubby primary root with at least two strong and vigorous adventitious roots, provided the hypocotyl is not shortened very much; (iii) a long welldeveloped hypocotyl; (iv) two intact cotyledons; or (v) slight infection by fungi, provided none of the essential seedling structures have been damaged.

(2) Abnormal seedlings include those that have: (i) No primary root, a stubby primary root only, or a stubby primar"