Inert matter shall include seeds and seed-like structures from both crop and weed plants and other material not seeds as follows:
(a) Seeds and seed-like structures from crop plants:
(1) Seeds of legumes (Leguminosae) and crucifers (Cruciferae) with the seed coats entirely removed. Refer to Sec. 210.48(a) for pure seed classification.
(2) Pieces of broken and damaged seed units, including those that are insect damaged, which are one-half the original size or less. If greater than one-half, refer to Sec. 201.48(b) and (c) for pure seed classification. Also included as inert matter are separated cotyledons of legumes, irrespective of whether or not the radicle-plumule axis and/or more than one-half of the seed coat may be attached.
(3) Chalcid-damaged seeds (puffy, soft, or dry and crumbly) of alfalfa, red clover, crimson clover, and similar kinds of small seeded legumes. Refer to Sec. 201.48(c) for pure seed classification.
(4) Glumes and empty florets except as stated under pure seed. Refer to Sec. 201.48 (g) and (h) for pure seed classification.
(5) Seed units with nematode galls or fungal bodies (smut, ergot, and other sclerotia) that are not entirely enclosed within the seed unit. Refer to Sec. 201.48(h) for pure seed classification.
(6) Broken seed units of Chenopodiaceae and fruit portions or fragments of monogerm beets, New Zealand spinach, buffalograss, and families in which the seed unit is a dry indehiscent one-seeded fruit that visibly do not contain a seed. Refer to Sec. 201.48 (f), (g)(1), (i), and (j) for pure seed classification.
(7) Seed units of forage kochia that pass through a 1 mm opening, square-hole sieve, when shaken for 30 seconds.
(8) The thin pericarp (fruit wall), if present on seeds of northern sweetvetch.
(9) Immature florets of smooth brome, fairway crested wheatgrass, standard crested wheatgrass, tall wheatgrass, intermediate wheatgrass, pubescent wheatgrass, western wheatgrass, fescues (Festuca spp.), and ryegrasses (Lolium spp.) in which the caryopses are less than one-third the length of the palea; the caryopsis is measured from the base of the rachilla.
(b) Seeds and seed-like structures from weed plants, which by visual examination (including the use of light or dissection), can be determined to be within the following categories:
(1) Damaged seed (other than grasses) with over one-half of the embryo missing.
(2) Grass florets and caryopses classed as inert:
(i) Glumes and empty florets of weedy grasses;
(ii) Damaged grass caryopses, including free caryopses, with over one-half the root-shoot axis missing (the scutellum excluded);
(iii) Immature free caryopses devoid of embryo and/or endosperm;
(iv) Immature florets of quackgrass (Agropyron repens) in which the caryopses are less than one-third the length of the palea. The caryopsis is measured from the base of the rachilla;
(v) Free caryopses of quackgrass (A. repens) that are 2 mm or less in length.
(3) Seeds of legumes and species of Brassica with the seed coats entirely removed.
(4) Immature seed units, devoid of both embryo and endosperm, such as occur in but not limited to the following plant families: Sedge (Cyperaceae), buckwheat (Polygonaceae), morning glory (Convolvulaceae), nightshade (Solanaceae), puncturevine (Zygophyllaceae) and sunflower (Compositae). Cocklebur (Xanthium spp.) burs are to be dissected to determine whether or not seeds are present.
(5) Wild onion and wild garlic (Allium spp.) bulblets:
(i) Bulblets which are completely devoid of the husk and pass through a 1/13th-inch, round-hole sieve.
(ii) Bulblets which show evident damage to the basal end, whether husk is present or absent. Refer to Sec. 201.50(c) for wild onion and wild garlic (Allium spp.) bulblets classed as weed seeds.
(6) Dodder (Cuscuta spp.): Seeds devoid of embryos and seeds which are ashy gray to creamy white in color are inert matter. Seeds should be sectioned when necessary to determine if an embryo is present as when seeds have a normal color but are slightly swollen, dimpled or have minute holes.
(7) Buckhorn (Plantago lanceolata): Black seeds, with no brown color evident, whether shriveled or plump; the color of questionable seeds shall be determined by use of a stereoscopic microscope with magnification of approximately 10x and a fluorescent lamp with two 15-watt daylight-type tubes.
(8) Ragweed (Ambrosia spp.): Seed with both the involucre and pericarp absent.
(c) Other matter that is not seed:
(1) Free nematode galls or fungal bodies such as smut, ergot, and other sclerotia.
(2) Soil particles, sand, stone, chaff, stems, leaves, flowers, loose coating material, and any other foreign material.
(3) Coating material removed from coated seed by washing. Refer to Sec. 201.51b(c). [46 FR 53637, Oct. 29, 1981; 46 FR 58059, Nov. 30, 1981, as amended at 59 FR 64498, Dec. 14, 1994; 65 FR 1707, Jan. 11, 2000; 76 FR 31794, June 2, 2011] Sec. 201.51a Special procedures for purity analysis.
(a) The Uniform Blowing Procedure shall be used for the separation of pure seed and inert matter in the following: Kentucky bluegrass, Canada bluegrass, rough bluegrass, Pensacola variety of bahiagrass, orchardgrass, blue grama, and side-oats grama.
(1) When kinds listed in this section appear in mixtures they shall be separated from other kinds before using the Uniform Blowing Procedure.
(2) To determine the blowing point for these procedures, individual calibration samples for Kentucky bluegrass, orchardgrass, and Pensacola variety of bahiagrass shall be used. The calibration sample for Kentucky bluegrass shall be used for Canada bluegrass, rough bluegrass, blue grama, and side-oats grama.
(i) The blowing point for Canada bluegrass shall be the same as the blowing point determined for Kentucky bluegrass.
(ii) The blowing point for rough bluegrass shall be a factor of 0.82 (82 percent) of the blowing point determined for Kentucky bluegrass. The 0.82 factor is restricted to the General-type seed blower.
(iii) The blowing point for blue grama shall be a factor of 1.157 of the blowing point determined for Kentucky bluegrass. Before blowing, extraneous material that will interfere with the blowing process shall be removed. The sample to be blown shall be divided into four approximately equal parts and each blown separately. The 1.157 factor is restricted to the General-type seed blower.
(iv) The blowing point for side-oats grama shall be a factor of 1.480 of the blowing point determined for Kentucky bluegrass. Before blowing, extraneous material that will interfere with the blowing process shall be removed. The sample to be blown shall be divided into four approximately equal parts and each part blown separately. The 1.480 factor is restricted to the General-type seed blower.
(3) Calibration samples and instructions are available on loan through the Seed Regulatory and Testing Branch, LS, AMS, Building 306, Room 213, Beltsville, Maryland 20705.
(4) The calibration samples shall be used to establish a blowing point prior to proceeding with the separation of pure seed and inert matter for these kinds. After completing the blowing procedure, remove all weed and other crop seeds from the light portion and add these to the weed or other crop separation, as appropriate. The remainder of the light portion shall be considered inert matter. Remove all weed and other crop seeds and other inert matter (stems, leaves, dirt) from the heavy portion and add these to the weed seed, other crop seed, or inert matter separations, as appropriate. The remainder of the heavy portion shall be considered pure seed.
(5) With orchardgrass, after the blowing, proceed with the multiple unit procedure.
(b) The Multiple Unit Procedure of determining the pure seed fraction shall be used only for the kinds included in the following table when multiple units are present in a sample. These methods are applicable to the kinds listed when they occur in mixtures or singly. Any single unit without attached structures, as described below, shall be considered a single unit. Multiple units and single units for the kinds listed shall remain intact. The attached glumes and fertile or sterile florets shall not be removed from the fertile floret.
(1) A multiple unit is a seed unit that includes one or more structures as follows (the length of the awn shall be disregarded when determining the length of a fertile floret or an attached structure):
(i) An attached sterile or fertile floret that extends to or beyond the tip of a fertile floret;
(ii) A fertile floret with basally attached glume, glumes, or basally attached sterile floret of any length;
(iii) A fertile floret with two or more attached sterile and/or fertile florets of any length.
(2) Procedure for determination of multiple units:
(i) For the single kind: determine the percentage of single units present, based on the total weight of single units and multiple units. Apply the appropriate factor, as determined from the following table, to the weight of the multiple units and add that portion of the multiple unit weight to the weight of the single units. The remaining multiple unit weight shall be added to the weight of the inert matter.
(ii) For mixtures that include one or more of the kinds in the following table, determine the percentage of single units, based on the total weight of single units and multiple units, for each kind. Apply the appropriate factor as determined from the following table, to the weight of multiple units of each kind.
Table of Factors To Apply to Multiple Units \a\--------------------------------------------------------------------------------------------------------------------------------------------------------
Pubes-
Chewings Red Orchard- Crested cent Intermediate Tall Western Smooth
Percent of single units of each kind fescue fescue grass wheat- wheat- wheat-grass wheat- wheat- brome
grass \b\ grass grass \c\ grass \c\--------------------------------------------------------------------------------------------------------------------------------------------------------50 or below........................................... 91 80 80 70 66 72 -- -- 7250.01-55.00........................................... 91 81 81 72 67 74 -- -- 7455.01-60.00........................................... 91 82 81 73 67 75 -- -- 7560.01-65.00........................................... 91 83 82 74 67 76 -- -- 7665.01-70.00........................................... 91 84 82 75 68 77 -- 60 7870.01-75.00........................................... 91 86 82 76 68 78 -- 66 7975.01-80.00........................................... 91 87 83 77 69 79 50 67 8180.01-85.00........................................... 91 88 83 78 69 80 55 68 8285.01-90.00........................................... 91 89 83 79 69 81 65 70 8390.01-100.00.......................................... 91 90 84 79 70 82 70 74 85--------------------------------------------------------------------------------------------------------------------------------------------------------\a\ The factors represent the percentages of the multiple unit weights which are considered pure seed. The remaining percentage is regarded as inert
matter.\b\ Includes both standard crested wheatgrass and fairway crested wheatgrass.\c\ Dashes in table indicate that no factors are available at the levels shown. [59 FR 64498, Dec. 14, 1994] Sec. 201.51b Purity procedures for coated seed.
(a) The working sample for coated seed is obtained as described in Sec. 201.46(d) (1) and (2), and weighed in grams to four significant figures.
(b) Any loose coating material shall be sieved, weighed, and included with the inert matter component.
(c) Coating material is removed from the seed by washing with water or other solvents such as, but not limited to, dilute sodium hydroxide (NaOH). Use of fine mesh sieves is recommended for this procedure, and stirring or shaking the coated units may be necessary to obtain de-coated seed.
(d) Spread de-coated seed on blotters or filter paper in a shallow container. Air dry overnight at room temperature.
(e) Separation of component parts:
(1) Kind or variety considered pure seed.
(2) Other crop seed.
(3) Inert matter.
(4) Weed seed.
(f) The de-coated seed shall be separated into four components in accordance with Secs. 201.48 through 201.51. Secs. 201.51a (a) and (b) shall not be followed. The weight of the coating material is determined by subtracting the sum of the weights of the other four components from the original weight of the working sample. The percentage of coating material shall be included with the inert matter percentage. Calculate percentages of all components based on the original weight of the working sample (see paragraph (a) of this section). [59 FR 64499, Dec. 14, 1994]