1 The land must be free of volunteer plants of the crop kind during the year immediately prior to establishment and no manure or other contaminating material shall be applied the year previous to seeding or during the establishment and productive life of the stand. 2 At least 2 years must elapse between destruction of indistinguishable varieties or varieties of dissimilar adaptation and establishment of the stand for the production of the Certified class 3 Isolation distance for certified seed production shall be at least 500 feet from varieties of dissimilar adaptation. This distance applies when fields are 5 acres or larger in area. For smaller fields, the distances are 900 feet and 450 feet for the Foundation and Registered classes, respectively. 7 Requirement is waived if the previous crop was grown from certified seed of the same variety. 8 Requirement is waived if the previous crop was of the same variety and of a certified class equal or superior to that of the crop seeded. Reseeding varieties of crimson clover may be allowed to volunteer back year after year on the same ground. If a new variety is being planted where another variety once grew, the field history requirements apply. 11 When the contaminant is of the same color and texture, the isolation distance may be modified by (1) adequate natural barriers, or (2) differential maturity dates, provided there are no receptive silks in the seed parent at the time the contaminant is shedding pollen. In the case of inbred lines and foundation single crosses, these modifications may apply only for fertile seed production. 12 Where the contaminating source is corn of the same color and texture as that of the field inspected, the isolation distance is 410 feet and may be modified by the planting of pollen parent border rows according to the following table: 13 Refers to off-type plants in the pollen parent that have shed pollen or to the off-type plants in the seed parent at the time of the last inspection. 14 The required minimum isolation distance for sweet corn is 660 feet from the contaminating source, plus four border rows when the field to be inspected is 10 acres or less in size. This 16 The Merion variety of Kentucky bluegrass is allowed 3 percent. 15 Refers to off-type ears. Ears with off-colored or different textured kernels are limited to 0.5 percent, or a total of 25 off-colored or different textured kernels per 1,000 ears. 19 Minimum isolation shall be at least 100 feet if the cotton plants in the contaminating source differ by easily observable morphological characteristics from the field to be inspected. Isolation distance between upland and Egyptian types shall be at least 1,320, 1,320, and 660 feet for Foundation, Registered, and Certified classes, respectively. 20 These distances apply when there is no border removal. Border removal applies only to fields of 5 acres or more. Removal of a 9-foot border (after flowering) decreases the required 25 The minimum distance may be reduced by 50 percent if different classes of the same variety are involved. 26 The minimum distance may be reduced by 50 percent if the field is adequately protected by natural or artificial barriers. 27 These ratios are for definite other varieties. The ratios for doubtful other varieties are: 1 Not applicable. 28 Whiteheart fruits may not exceed 1 per 100, 40 and 20 for Foundation, Registered, and Certified classes, respectively. Citron or hard rind is not permitted in Foundation or Registered 33 Unless the preceding crop was another kind or unless the preceding soybean crop was planted with a class of certified seed of the same variety, or unless the preceding soybean crop 35 Standards apply equally to seed parents and pollen parents which may include up to 1:1,000 plants each of the wild-type branching, purple or white-seeded plants. 37 This distance is applied between varieties of the same type and may be waived if four border rows of each variety are allowed to bloom and set seed between the two varieties but are 43 Parent lines (A and B) in a crossing block, or seed and pollen lines in a hybrid seed production field, shall be separated by at least 6 feet and shall be managed and harvested in a 45 An isolation distance of 5,280 feet is required between oil and non-oil sunflower types and between either type and other volunteers or wild types. 46 Detasseling, cutting, or pulling of the cytoplasmic male-sterile seed parent is permitted. 47 All varieties of perennial ryegrass seed are allowed 3.0 percent. 48 This distance applies for fields over 5 acres. For alfalfa fields of 5 acres or less that produce the Foundation and Registered seed classes, the minimum distance from a different variety 49 There must be at least 10 feet or a distance adequate to prevent mechancial mixture between a field of another variety (or noncertified area within the same field) and the area being [46 FR 53639, Oct. 29, 1981; 46 FR 58059, Nov. 30, 1981; 46 FR 59527, Dec. 7, 1981] 73-009 0-86--19 ADDITIONAL REQUIREMENTS FOR THE CERTIFICATION OF PLANT MATERIALS OF CERTAIN CROPS § 201.77 Length of stand requirements. (a) Alfalfa. Limitations on the age of stand and certified seed classes through which a given variety may be multiplied both inside and outside its region of adaptation shall be specified by the originator or his designee. Certified seed production outside the region of adaptation shall not exceed 6 years if not otherwise specified by the originator, or his designee. (b) Red clover. Only two seed crops are permitted of all certified seed classes. (c) White and alsike clover. Only two successive seed crops are permitted following the year of establishment for Foundation and Registered classes, but 2 additional years are permitted if the field is reclassified to the next lower class. Four successive seed crops following seeding are permitted if the first and succeeding crops are of the Certified class, provided the stand of perennial plants is maintained. (d) Sainfoin. All certified seed classes are eligible to produce five successive seed crops following seeding. [38 FR 25664, Sept. 14, 1973] § 201.78 Pollen control for hybrids. (a) Wheat and barley. Shedders in the seed parent, at any one inspection, are limited to 1:200 heads for Foundation A Line and 1:100 heads for Registered A Line, except that when the A Line is increased outside the area of the anticipated A x R production in order to utilize self-fertility produced by environmental effects, only isolation and genetic purity standards will be in effect. (An A Line is a cytoplasmic male sterile female line used to produce hybrid seed. An R Line is a pollinator line used to pollinate an A Line and to restore fertility in the resulting hybrid seed.) (b) Corn. When 5 percent or more of the seed parent plants have receptive silks, shedding tassels in the seed parent plants shall be limited to 1 percent at any one inspection, or a total of 2 percent at any three inspections on different dates. Shedding tassels are those which have 2 inches or more of the central stem or branches, or any combination thereof, shedding pollen. (c) Sorghum. Shedders in the seed parent, at any one inspection, are limited to 1:3,000 plants for Foundation class and 1:1,500 plants for Certified class. (d) Sunflowers. Seed parents flowering and shedding pollen before the male parents are shedding pollen must be removed. At least 50 percent of the male plants must be producing pollen when the seed parent is in full bloom. (e) Hybrid alfalfa. When at least 75 percent of the plants are in bloom and there is no more than 15 percent seed set, 200 plants shall be examined to determine the pollen production index (PPI). Each plant is rated as 1, 2, 3 or 4 with "1" representing no pollen, "2" representing a trace of pollen, "3" representing зubstantially less than normal polen, and "4" representing normal pollen. The rating is weighted as 0, 0.1, 0.6 or 1.0, respectively. The total number of plants of each rating is multiplied by the weighted rating and the values are totaled. The total is divided by the number of plants rated and multiplied by 100 to determine the PPI. The maximum PPI allowed is 14 for the Foundation class, and 6 for 95 percent hybrid seed, and 42 for 75 percent hybrid seed of the Certified class. [38 FR 25664, Sept. 14, 1973, as amended at 41 FR 20158, May 17, 1976] IMPORTED SEED 8 201.101 Exemptions. For the purpose of section 302(c)(2) the act, seeds of the following kinds are found to be imported in a substantial proportion for other than seeding purposes and are exempted from the import provisions (Title III) of the act when imported for other than seeding purposes: Provided, That they are accompanied by declarations when and as required under § 201.222: Barley. Bean, Adzuki. Bean, horse or broad. Buckwheat, common. |