Maximum Field Tolerances as % for Certification (Based on Visual Inspections)
Disease
Generation 2
Generation 3
Generation 4
Generation 5
Leafroll
0.05
0.1
0.2
0.2
Mosaic
0.1
0.2
0.5
0.5
Spindle Tuber
0.0
0.0
0.0
0.0
Calico
0.15
0.3
1.0
1.0
Total All Non-latent Viruses
0.2
0.4
1.0
0.1
Haywire
0.1
0.2
0.5
0.5
Witches Broom
0.1
0.2
0.5
0.5
Giant Hill
0.05
0.1
0.5
0.5
Variety Mix
0.05
0.1
0.5
0.5
Volunteer Potatoes (same var.)
0.05
0.1
0.5
0.5
Bacterial Ring Rot
0.0
0.0
0.0
0.0

Columbia Root Knot Nematode (visible symptoms)
0.0
0.0
0.0
0.0

The 0.0% tolerance is not intended, nor may it be construed to mean that the lot inspected is free from the disease. In cases of bacterial ring rot and Columbia root knot nematode, it means only that said disease was not identified during the visual inspection process. In cases of other disease, it means only that the diseased plants observed were required to be rogued out.