TABLE 2-Germination Requirements for Indicated Kinds-Continued

Watermelon-Citrullus lanatus..

1 Hard seeds often present. Firm ungerminated seeds frequently present.

Rhizomatous derivatives of a johnsongrass x sorghum cross or a johnsongrass X sudangrass cross.

[20 FR 7928, Oct. 21, 1955]

EDITORIAL NOTE: For FEDERAL REGISTER citations affecting 201.58, see the List of CFR Sections Affected in the Finding Aids section of this volume.

EXAMINATIONS IN THE ADMINISTRATION OF THE ACT

§ 201.58a Indistinguishable seed.

When the identification of the kind, variety, or type of seed or determination that seed is hybrid is not possible by seed characteristics, identification may be based upon the seedling, growing plant, or mature plant characteristics according to such authentic information as is available.

(a) Ryegrass. In determining the proportions of perennial and annual or Italian ryegrass seed, 400 seeds shall be grown on filter paper and the number of fluorescent seedlings determined under ultraviolet light at the end of the germination period. The percentages of pure ryegrass seed, normal fluorescent seedlings, and normal nonfluorescent seedlings shall be determined. The percentage of normal fluorescent seedlings or normal nonfluorescent seedlings is the number of each found in the test divided by the total number of seeds in the test. The results shall be applied as follows:

(1) If the quotient obtained by dividing the number of normal fluorescent seedlings by the number of normal seedlings is greater than 75 percent, the following formula shall be used: Percent annual or Italian ryegrass=(% fluorescent seedlings >% pure ryegrass)/% germination

The percentage of perennial ryegrass is determined by subtracting the percentage of annual or Italian ryegrass found from the percentage of pure ryegrass.

(2) If the quotient referred to in paragraph (a)(1) of this section is 75 percent or less, the following formula shall be used:

Percent perennial ryegrass=(1.0526×% nonfluorescent seedlings>% pure ryegrass)/ % germination

The percentage of annual or Italian ryegrass is determined by subtracting the percentage of perennial ryegrass found from the percentage of pure ryegrass.

(3) Varieties of annual or perennial ryegrass having as a characteristic a percentage of fluorescence less than 100 percent for an annual variety or

more than 5 percent for a perennial variety shall not be subjected to the formulas in paragraphs (a)(1) and (2) of this section for a determination as to kind. Varieties in commercial channels in the United States which are not subjected to the above formulas include but are not limited to the following:

Ariki. Magnolia.

(b) Sweetclover. In determining the percentage of yellow blossom sweetclover in a mixture of yellow and white blossom sweetclover, at least 400 seeds shall be examined to determine the percentage of mottled seed. The percentage of mottled seed shall be multiplied by four and this product multiplied by the percentage of sweetclover in the sample. The product shall be construed as representing the percentage of yellow blossom sweetclover.

(c) Wheat. In determining the varietal purity, the phenol method may be used according to the procedure given in the Association of Official Seed Analysts, Handbook No. 28 "A Standardized Phenol Method for Testing Wheat Seed for Varietal Purity", June 1965.

[5 FR 35, Jan. 4, 1940]

EDITORIAL NOTE: For Federal Register citations affecting § 201.58a, see the List of CFR Sections Affected in the Finding Aids section of this volume.

§ 201.58b Origin.

The presence of incidental weed seeds, foreign matter, or any other existing circumstances shall be considered in determining the origin of seed.

[5 FR 35, Jan. 4, 1940. Redesignated at 20 FR 7940, Oct. 21, 1955]

8 201.58c Detection of captan, mercury, or thiram on seed.

The bioassay method may be used according to the procedure given in Association of Official Seed Analysts, Handbook No. 26, "Microbiological Assay of Fungicide-treated Seeds", May 1964.

[38 FR 12733, May 15, 1973]