Notice to Seed Graders - Assigning a Pedigreed Grade Name to a Seed Lot of a Large-Seeded Crop Kind with Visually Distinguishable Varietal Impurities

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In Canada, when seed of one variety is found in seed of another variety of the same crop kind, it is considered a varietal impurity. For example: if seed of a red lentil variety is found in seed of a green lentil variety, the red seeds must be counted and classified as varietal impurities. Varietal impurities should only be considered when grading pedigreed (certified) seed.

Varietal impurities are not included as weed seeds or seed of other crop kinds in the Grade Tables (in Schedule I to the Seeds Regulations (the Regulations)). Although pedigreed seed crop inspections, which are conducted under the supervision of the Canadian Food Inspection Agency (CFIA), remain the primary method for assessing varietal purity in Canada, pedigreed seed must also meet the seed crop varietal purity standards of the Canadian Seed Growers' Association (CSGA) as required by paragraph 10(5)(d) of the Regulations. The CSGA seed crop varietal purity standards are based on the Association of Official Seed Certifying Agencies (AOSCA) Certification Handbook except for field peas which are in Section 1.20.2 of the CSGA's Canadian Regulations and Procedures for Pedigreed Seed Crop Production (Circular 6).

Varietal purity standards for the large-seeded crop kinds listed in Grade Tables I to VI and XVIII are provided below in two tables: Table 1 presents the standards in percentages and Table 2 presents the standards in numbers of impurities per kilogram. Varietal purity should not be assessed for non-pedigreed or common seed as there are no varietal purity standards.

A seed grader's responsibility to assess seed varietal purity extends only to the identification of visually distinguishable varietal impurities found during the examination of the grading sample of large-seeded crop kinds. Variations in seed characteristics that are due to environmental factors are not considered varietal impurities. Where a Report of Analysis from an Accredited Seed Lab is being used to assign a pedigreed grade name to a lot of a large-seed crop kind, the grader can determine if the seed varietal purity standard has been met by noting if any level of varietal contamination is reported in the 'Remarks' portion of the Report of Analysis.

Examples of visually distinguishable varietal impurities include, but are not limited to:

  • red kidney beans in a white kidney bean variety;
  • striped sunflower seeds in a black-seeded sunflower variety;
  • red wheat kernels in a wheat variety with white kernels; and
  • pubescent canaryseed in a glabrous canaryseed variety.

Some varieties are described as including an acceptable level of variants - plants (or seeds) that do not conform to the norm of the variety, but are considered a part of the variety. Variants have known, stable characteristics and occur at a specified frequency in the variety as compared to off-types which may exhibit varied characteristics and occur at variable frequency. Variants are not counted as off-types unless the number found exceeds the frequency described in the official description of the variety. In this case, the number of variants in excess of the permitted number must be counted as off-types. Variants are especially common in varieties of winter wheat and soybeans.

If the number of impurities in a grading sample is such that the sample fails to meet the standards in Tables 1 and 2 below, graders should email the CFIA Seed Section with the following information before assigning a grade:

  • the name of the variety;
  • a description of the contaminating seed; and
  • the level of contamination.

If the CFIA Seed Section reviews the official variety description and determines that the level of contamination exceeds seed varietal purity standards for the pedigreed status indicated on the crop certificate, then the pedigreed status and pedigreed grade name of the seed lot must be demoted to meet the reported level of seed varietal purity. The grader must:

  1. Include the statement: "Demoted due to varietal off-types in excess of the AOSCA seed varietal purity standard" on the seed grading report.
  2. On the demoted pedigreed seed tag or label, change the third last digit on the crop certificate (example: 12-1234567-101) to the letter representing the demoted pedigreed status (F-Foundation, R-Registered and C-Certified; example: 12-1234567-C01). If the demotion results in a loss of pedigreed status, the seed can only be sold as non-pedigreed or common seed. For crop kinds listed in Schedule II (which includes most major crop kinds), non-pedigreed seed cannot be sold by variety name.
  3. On the Pedigreed Seed Declaration, use the original crop certificate number but indicate the demoted status on the tag that was used when sealing the lot.
  4. Record the demotion, with the statement above, on the disposal record.

Graders must contact the CSGA to request a new crop certificate number when demoting Select status seed to a lower pedigreed seed class.

Table 1. Maximum percentages of visually distinguishable varietal impurities permitted in large-seeded crop kinds listed in Tables I to VI and XVIII of Schedule I to the Seeds Regulations.
Crop Grade Table(s) Foundation Status Registered Status Certified Status
Barley II 0.05 0.10 0.20
Buckwheat II 0.05 0.10 0.20
Canarygrass IV 0.01 1.0 2.0
Chickpea V, XVIII 0.05 0.10 0.20
Corn (sweet,
open pollinated, hybrid)
XVIII, V, VI n/a n/a 0.50
Cowpea V 0.01 0.20 0.50
Fababean V, XVIII 0.05 0.10 0.20
Field Bean V, XVIII 0.05 0.10 0.20
Field Pea V, XVIII 0.02 0.05 0.20
Flax IV 0.05 0.10 0.20
Lentil II 0.05 0.10 0.20
Lupin II 0.01 0.02 0.05
Mung Bean II 0.10 0.20 0.50
Oats II 0.20 0.30 0.50
Rye II 0.05 0.10 0.20
Safflower V, XVIII 0.01 0.05 0.10
Sainfoin II.1 0.10 0.25 1.00
Sorghum IV 0.005 0.01 0.05
Sorghum, commercial hybrid IV n/a n/a 0.10
Soybean V, XVIII 0.10 0.20 0.50
Sunflower, open pollinated V 0.02 0.02 0.10
Sunflower, hybrid VI 0.02 n/a 0.10
Triticale II 0.05 0.10 0.20
Vetch II.1 0.10 0.25 1.00
Wheat I 0.05 0.10 0.20
Table 2. Maximum number of visually distinguishable varietal impurities allowed per kilogram of large-seeded crop kinds listed in Tables I to VI and XVIII in Schedule I to the Seeds Regulations.
Crop Grade Table(s) No. of Seeds/ kg Foundation Status Registered Status Certified Status
Barley II 30,000 15 30 60
Buckwheat II 45,000 23 45 90
Canarygrass IV 150,000 15 1500 3000
Chickpea V, XVIII 3,000 2 4 8
Corn (sweet,
open pollinated, hybrid)
XVIII, V, VI 3,000 n/a n/a 15
Cowpea V 8,000 1 16 40
Fababean V, XVIII 2,000 1 2 4
Field Bean V, XVIII 4,000 2 4 8
Field Pea V, XVIII 4,000 1 2 8
Flax IV 180,000 90 180 360
Lentil II 40,000 20 40 80
Lupin II 7,000 1 2 4
Mung Bean II 24,000 24 48 120
Oat II 40,000 80 120 200
Rye II 40,000 20 40 80
Safflower V, XVIII 30,000 3 15 30
Sainfoin II.1 50,000 50 125 500
Sorghum IV 55,000 3 6 28
Sorghum, commercial hybrid IV 100,000 n/a n/a 100
Soybean V, XVIII 6,000 6 12 30
Sunflower, open pollinated V 9,000 2 2 9
Sunflower, hybrid VI 9,000 2 n/a 9
Triticale II 50,000 25 50 100
Vetch II.1 25,000 25 63 250
Wheat I 25,000 13 25 50
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