All seed potato classes are subject to the same tuber standards–there is only one quality grade for Canada Seed Potatoes. The total allowable disease and defects permitted in a graded seed potato lot are set out in section 48.1, subsections (2) – (10) of the Seeds Regulations. The following is a summary of the shipping point tolerances:
|
Disease or Defect |
Tolerence Level (%) |
Soft rot or wet breakdowns |
0.1 |
Dry Rot |
1 |
Scab or Rhizoctonia – light |
10 |
Scab or Rhizoctonia – moderate |
5 |
Stem-end discolouration due to top-killing, frost, heat, or drought with penetration from 6 – 13 mm |
4 |
Tubers malformed or externally damaged |
2 |
Total number of tubers affected by disease and defects, not including slight scab and rhizoctonia and stem-end discolouration |
5 |
Soft rot or wet breakdowns
In addition there should be no more than the following levels of foreign varieties: not more then 0.05% in Elite III, not more than 0.10% in Elite IV, and not more than 0.20% in the Foundation and 0.50% in the Certified classes of seed.
