201.47 Separation.

(a) The working sample shall be weighed in grams to four significant figures and shall then be separated into four parts: (1) Kind or variety to be considered pure seed, (2) other crop seed, (3) weed seed, and (4) inert matter. The components shall be weighed in grams to the same number of decimal places as the working sample. The percentage of each part shall be determined to two decimal places.

(b) Aids for the classification of pure seed, other crop seed, weed seed, and inert matter may include visual examination, use of transmitted light, (diaphanoscope), or specific gravity (seed blowers). Specific instructions for classification of the various components are given in §§ 201.47a to 201.51, inclusive.

(c) The components shall be weighed and percentages calculated as follows:

(1) For sample sizes less than 25 grams, all four components shall be weighed; the percentages shall be based on the sum of these weights and not on the original weight. The sum of these weights shall be compared with the original weight of the working sample as a check against the loss of material, or other errors.

(2) For sample sizes of 25 grams or more, the components-other crop seed, weed seed, and inert matter-shall be weighed separately and their percentages determined by dividing these weights by the original weight of the working sample. The pure seed need not be weighed; its percentage may be determined by subtracting the sum of the percentages of the other three components from 100.

(d) When the working sample consists of two or more similar kinds or varieties which would be difficult to separate in the entire sample, it is permissible to weigh the similar kinds or varieties together as one component and make the separation on a reduced portion of the sample. At least 400 seeds or an equivalent weight shall be taken indiscriminately from the pure seed component and the separation made on this portion. The proportion of each kind present shall then be determined by weight and from this the percentage in the entire sample shall be calculated.

(e) The uniform method as adopted by the Association of Official Seed Analysts, as amended effective October 1, 1970, shall be used for the separation of pure seed and inert matter in seeds of Ken

tucky bluegrass, "Pensacola" variety of bahiagrass and orchardgrass.

[25 F.R. 8770, Sept. 13, 1960, as amended at 30 FR 7890, June 18, 1965; 35 FR 6108, Apr. 15, 1967; 38 FR 12731, May 15, 1978]

§ 201.47a Seed unit.

The seed unit is the structure usually regarded as a seed in agricultural practices and in commercial channels. The seed unit may consist of one or more of the following structures:

(a) True seeds;

(b) Caryopses and floretes in the grass family. In this family the pure seed unit also includes the following structures for the indicated kinds:

(1) Spikelet or paired spikelets with at least one caryopsis in the bluestems (Andropogon) and yellow Indiangrass (Sorghastrum nutans),

(2) Spikelet with at least one caryopsis in the gramas (Bouteloua), or spike with at least one caryopsis in side-oats grama (B. curtipendula),

(3) Bur or fertile floret of buffalo grass (Buchloe dactyloides),

(4) Fascicle of buffel grass (Pennisetum ciliare),

(5) Bulblet of bulbous bluegrass (Poa bulbosa);

(c) Dry indehiscent fruits in the following plant families: Buckwheat (Polygonaceae), sunflower (Compositae), geranium (Geraniaceae), goosefoot (Chenopodiaceae), and valerian (Valerianaceae) ;

(d) One- and two-seeded pods of small-seeded legumes, burs of the bur clovers, and pods of peanuts. (This does not preclude the shelling of small-seeded legumes for purposes of identification.) Pods of legumes normally containing more than two seeds, when occurring incidentally in the working samples, should be hulled if the kind is usually hulled when marketed.

(e) Fruits or half fruits in the carrot family (Umbelliferae);

(f) Nutlets in the following plant families: Borage (Boraginaceae), mint (Labiateae), vervain (Verbenaceae);

(g) "Seed balls" or portions thereof in beets (Beta), and fruits with accessory structures such as occur in New Zealand spinach (Tetragonia expansa). [20 F.R. 7930, Oct. 21, 1955, as amended at 35 F.R. 8770, Sept. 13, 1960]

§ 201.47b Working samples.

The purity working sample is the sample on which the purity analysis is made. The noxious-weed seed working sample is the sample on which the noxious-weed seed examination is made.

[20 F. R. 7930, Oct. 21, 1955]

§ 201.48 Kind or variety considered pure seed.

The pure seed shall include all seeds of each kind or each kind and variety under consideration present in excess of 5 percent of the whole. Pure seed may include kinds and varieties present to an extent of 5 percent or less of the whole; for example, kinds or varieties shown on a label as parts of a mixture in amounts of 5 percent or less. The following shall be included with pure seed:

(a) Seeds that are immature, shriveled, cracked, insect-damaged or otherwise injured, except as provided in paragraph (1) of this section. (Seeds of legumes and crucifers with the seedcoat entirely removed shall be classified as inert matter. See § 201.51);

(b) Pieces of broken and otherwise damaged seeds that are larger than onehalf of the original size, except as provided in paragraph (1) of this section. (This excludes separated cotyledons of cowpea, peanut, and soybean, commonly referred to as "splits," irrespective of whether or not the radicle-plumule axis and/or more than half of the seed coat may be attached. In the case of soybean seed, if the two cotyledons are broken apart but held together by the seed coat, the seed shall be classed as pure seed. If only one cotyledon is in the seed coat, the seed shall be classed as inert.)

(c) Seeds that have started to germinate;

(d) Seeds of Cucurbitaceae and Solanaceae consisting principally of seedcoat (usually referred to as empty seed);

(e) Empty fruits (seed units) of species belonging to the following families: Sunflower (Compositae), buckwheat (Polygonaceae), carrot (Umbelliferae), valerian (Valerianaceae), mint (Labiateae), and other families in which the seed unit may be a dry, indehiscent, oneseeded fruit;

(f) All seed units of grasses in which a caryopsis with some degree of endosperm development can be detected either by slight pressure or by transmitted light (diaphanoscope).

(g) Multiple florets or entire spikelets of the following kinds of seeds when one or more of the florets contain a caryopsis: Bluegrasses (Foa), tall meadow oatgrass (Arrhenatherum elatius), Rhodesgrass (Chloris gayana), bluestems (Andropogon), gramas (Bouteloua), barley (Hordeum), and oats (Avena); also spikes of side-oats grama (Bouteloua curtipendula) containing at least one caryopsis. Attached empty florets of the following kinds need not be removed from fertile florets when the analysis is made by the special method described under $ 201.51a: Orchardgrass (Dactylis glomerata), Chewings fescue (Festuca rubra var. commutata), red fescue (Festuca rubra), fairway crested wheatgrass (Agropyron cristatum), standard crested wheatgrass (Agropyron desertorum), and intermediate wheatgrass (Agropyron intermedium).

(h) Diseased seeds, except ergots, smut balls, and other fungus bodies which are to be classed as inert matter. (See § 201.51);

(1) Insect-damaged seeds, provided that the damage is entirely internal, or that the opening in the seed coat is not sufficiently large to allow the size of the remaining mass of tissue to be readily determined. Weevil-infested vetch seeds, irrespective of the amount of insect damage, are to be considered pure seed unless they are broken pieces one-half or less than the original size. This provision is not applicable to chalcid-damaged seed (see § 201.51 (a) (4)).

(j) Seed units of New Zealand spinach, beets, and sugar beets, regardless of whether they contain true seeds: Provided, That in the case of segmented beet balls and sugar beet balls, small fragments which obviously do not contain true seeds shall be classified as inert matter.

[20 F.R. 7930, Oct. 21, 1955, as amended at 25 F.R. 8770, Sept. 13, 1960, 26 FR. 10035, Oct. 26, 1961, 28 FR 5361, May 30, 1963; 38 FR 12731, May 15, 1973]

§ 201.49 Other crop seed.

Seeds of plants grown as crops (other than the kind or variety included in the pure seed) shall be considered other crop seeds, unless recognized as weed seeds by applicable laws, or regulations, or by general usage. All interpretations and definitions for "pure seed" in § 201.48 shall also apply in determining whether seeds are other crop seed or inert matter. (20 F. R. 7980, Oct. 21, 1955]

§ 201.50 Weed seed.

Seeds, bulblets, sporocarps, or tubers of plants recognized as weeds by applicable laws or regulations, or general usage shall be considered weed seeds. Badly injured weed seeds and undeveloped, seedlike structures, including those of noxious-weed seeds, as described in § 201.51, shall be considered inert matter and not weed seeds. When seeds of Juncus tenuis, or other species of Juncus having seeds of a similar size, are present they may be included with the inert matter. However, clusters of Juncus seeds shall be included with the weed seeds. For species having seeds larger than Juncus (excluding Xanthium) the individual seeds are to be removed from fruiting structures. The seeds are placed with the weed seed and the remaining fruiting structures are placed in inert matter. (For single seeds of Juncus see 201.51(10).)

[20 F.R. 7930, Oct. 21, 1955 as amended at 28 F.R. 5361, May 30, 1963, 30 F.R. 7890, June 18, 1965; 38 FR 12731, May 15, 1973]

§ 201.51 Inert matter.

Inert matter shall include seeds and seedlike structures from both crop and weed plants and other material not seeds as follows:

(a) Seeds and seed-like structures from crop plants

(1) Pieces of broken or otherwise damaged seeds one-half the original size or less. Included are separated cotyledons of cowpea, peanut and soybean commonly referred to as "splits", irrespective of whether or not the radicle-plumule axis and/or more than half of the seed coat may be attached. (See § 201.48 (b) and (1)).

(2) Seeds of legumes and crucifers with the seedcoats entirely removed;

(3) Glumes and empty florets except when considered pure seed or other crop seed under §§ 201.48 and 201.49;

(4) Chalcid-damaged seeds (puffy, soft, or dry and crumbly) of alfalfa, red clover, crimson clover, and similar kinds of small-seeded legumes.

(5) Seed units of grasses in which the caryopses are replaced by nematode galls, or by fungus bodies such as smut balls or ergot sclerotia.

(b) Seeds and seed-like structures from weed plants which by visual examination (including the use of transmitted light or dissection) can be dem

onstrated as falling within the following categories

(1) Damaged

seeds (other than caryopses of grasses) with over one-half of the embryo missing;

(2) Damaged caryopses of grasses, including free caryopses of quackgrass, Agropyron repens, with over one-half the root-shoot axis missing (the scutella excluded); Immature grasses-florets of quackgrass in which the caryopses are less than one-third the length of the palea and free caryopses devoid of embryo; Undeveloped grasses-glumes and florets devoid of both embryo and endosperm.

(3) Seeds of legumes and species of Brassica with the seedcoats entirely removed;

(4) Undeveloped seed units, devoid of both embryo and endosperm, such as occur in the following plant families: Sedge (Cyperaceae), buckwheat (Polygonaceae), morning-glory (Convolvulacede), nightshade (Solanaceae), and sunflower (Compositae). Cocklebur (Xanthium spp.) burs are to be dissected to determine whether or not seeds are present. (See § 201.52.)

(5) Bulblets of wild onion and wild garlic (Allium) which are completely devoid of the husk and pass through a 13th-inch-round-hole sieve; bulblets which show evident damage to the basal end regardless of whether the husk is present or absent. (Bulblets which have any part of the husk remaining and are not damaged at the basal end are considered weed seeds regardless of size.)

(6) Dodder (Cuscuta): Seeds devoid of embryos. Questionable seeds should be sectioned. Questionable seeds include those that may have normal or near normal color, but are slightly swollen, dimpled, or with "pin-point" holes. Seeds that are ashy gray to creamy white in color are inert.

(7) Buckhorn (Plantago lanceolata): Black seeds with no brown color evident, whether shriveled or plump. (The color of questionable seeds shall be determined by the use of a stereoscopic microscope with magnification of approximately 10x and a fluorescent lamp with two 15-watt daylight type tubes.)

(8) Ragweed (Ambrosia): Seed with both the involucre and pericarp absent; (9) Single seeds of Juncus species. (See § 201.50.)

(c) Other matter

(1) Nematode galls, including galls enveloped by the lemma and palea of grass florets;

(2) Fungus bodies, such as ergot and other sclerotia, and smut balls;

(3) All inert matter such as soil particles, sand, stones, chaff, stems, and leaves.

[20 FR 7931, Oct. 21, 1955, as amended at 25 FR 8770, Sept. 13, 1960; 30 FR 7890, June 18, 1965; 38 FR 12731, May 15, 1973] § 201.51a Special procedures for purity analysis.

When the multiple units of the pure seed fraction (multiple florets or entire spikelets containing at least one caryopsis, to which is attached any type of inherent inert matter) of the kinds of grasses indicated in this section constitute 5 percent or more of the sample, it is not necessary to detach and separate the fertile florets from empty florets or other attached inert structures. The test may be made by the following procedure:

(a) Separate the multiple units and single units, weigh, and determine the percentage of each in the sample;

(b) If there is 5 percent or more of multiple units the weight of multiple units is multiplied by the appropriate fraction taken from the following tabulation. The weight obtained from this

Kind of seed

50 or 50.01less