§201.47a. Seed unit. — Inbound Citations

(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.

(1) Uniform Blowing Procedure in § 201.51a(a) for kinds listed in § 201.47(e) may be disregarded. If disregarded, all seed units (as defined in § 201.47a) for these kinds found in the working sample shall be manually separated into pure seed and inert matter. Only units containing at least one caryopsis with some degree of endosperm development which can be detected either by slight pressure or by examination over light are considered other crop seed.

(g) Seed units of the grass family listed in § 201.47a(b) (1) through (5) if a caryopsis with some degree of endosperm development can be detected in the units, either by slight pressure or by examination over light. Seed units of smooth brome, fairway crested wheatgrass, standard crested wheatgrass, tall wheatgrass, intermediate wheatgrass, pubescent wheatgrass, western wheatgrass, fescues (Festuca spp.), and ryegrasses (Lolium spp.) if the caryopses are at least one-third the length of the palea; the caryopsis is measured from the base of the rachilla. Species in which determination of endosperm development is not necessary are listed in paragraphs (g) (1) and (2) of this section. Refer to §§ 201.48(h) and 201.51(a)(5) when nematode galls and fungal bodies have replaced the caryopsis in seed units. The following procedures apply to determine pure seed in the grass families listed below:

(1) Intact burs of buffalograss (Bouteloua dactyloides) shall be considered pure seed whether or not a caryopsis is present. Refer to § 201.51(a)(6) for burs which are visibly empty.

(2) The Uniform Blowing Procedure described in § 201.51a(a) shall be used to determine classification of florets into pure seed or inert matter for Kentucky bluegrass, Canada bluegrass, rough bluegrass, Pensacola variety of bahiagrass, side-oats grama, blue grama, and orchardgrass.

(3) Special purity procedures for smooth brome, fairway crested wheatgrass, standard crested wheatgrass, intermediate wheatgrass, pubescent wheatgrass, tall wheatgrass, and western wheatgrass are listed in § 201.51a(b).

(4) For methods of determining pure seed percentages of annual and perennial ryegrass, refer to §§ 201.58(b)(10) and 201.58a(a).

(i) Refer to § 201.47a(g) and § 201.51(a)(6) for definitions of seed units and inert matter, respectively.