First Inspection Tolerances (%) Foundation Class Field Year | Certified Class Field Year | ||||||
1 | 2 | 3 | 4 | 5 | 6 | 0-6 | |
Varietal mixture | 0.1 | 0.2 | 0.3 | 0.5 | 0.5 | 0.5 | 0.5 |
Spindle tuber viroid | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
Severe mosaics (PVY) | 0.2 | 0.3 | 0.4 | 0.5 | 0.5 | 0.5 | 2.0 |
Leaf roll (PLRV) | 0.2 | 0.3 | 0.4 | 0.5 | 0.5 | 0.5 | 2.0 |
Total serious virus | 0.2 | 0.3 | 0.4 | 0.5 | 0.5 | 0.5 | 2.0 |
*Bacterial ring rot | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
Second and All Subsequent Inspections Tolerances (%) Foundation Class Field Year | Certified Class Field Year | ||||||
1 | 2 | 3 | 4 | 5 | 6 | 0-6 | |
Varietal mixture | 0.1 | 0.1 | 0.2 | 0.3 | 0.3 | 0.3 | 0.3 |
Spindle tuber viroid | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
Severe mosaics (PVY) | 0.0 | 0.1 | 0.2 | 0.3 | 0.3 | 0.3 | 2.0 |
Leaf roll (PLRV) | 0.0 | 0.1 | 0.2 | 0.3 | 0.3 | 0.3 | 2.0 |
Total serious virus | 0.0 | 0.1 | 0.2 | 0.3 | 0.3 | 0.3 | 2.0 |
*Bacterial ring rot | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
Late blight found during field inspection must be confirmed by symptoms or laboratory diagnosis before being reported on the inspection report.
* The zero tolerance means that no amount is permissible when inspected. It does not mean that the seed is absolutely free of disease or disease-causing agents, but that none was found during inspection.
Varieties that do not express visible disease symptoms. Potato varieties that do not express visible disease symptoms of a specific pathogen may be subjected to a laboratory test to determine the levels of the pathogen in a seed lot. This testing may occur during the growing season or during the winter test, or both, and may affect eligibility of the seed lot.
Ring rot. Seed fields will be subject to a third (final) field inspection focused primarily on inspection for symptoms related to ring rot. If the field has not received a third inspection, the grower will be required to submit a four hundred tuber sample (minimum) per field for laboratory testing.
Blackleg. Since the blackleg disease may be latent, the inspector will record only the percentage observed during the first and second inspection, and no tolerance will be established. However, any excessive amount can be cause for rejection. Blackleg observations shall be based upon sample plants exhibiting the characteristic black, inky, soft, slimy, decomposed tissue of the stem.
Wilt. Only the percentage noted will be recorded on the first and second inspection, and may include other factors such as maturity, drought, or alkali problems but any excessive amount may be cause for rejection.
There will be zero tolerance for potato wart, corky ring spot, gangrene, golden nematode, root knot nematode, tuber moths, or other such injurious pests that have never been found and confirmed in North Dakota seed potato fields.
Tolerances for potato virus x tested seed. All of the above tolerances will apply, including a requirement that bacterial ring rot must not have been found on the farm during the season. Seed lots with no more than two percent potato virus x infection may be identified as virus x tested on certification labels.
N.D. Admin Code 74-04-01-08
General Authority: NDCC 28-32
Law Implemented: NDCC 4.1-55-02