Figure: 4 TAC §10.50(a)

All Certified Seed
Grade Defect for Tubers	Maximum %
Stem end discoloration	5.0
Net Necrosis (Leafroll, after laboratory identification)	0.5
Net Necrosis (aster yellows)	2.0
Bacterial Ring Rot	0
Root Knot Nematode (visible tuber symptoms)	0
Corky Ring Spot (visible tuber symptoms coupled with confirmation of Tobacco Rattle Virus presence by accepted laboratory test)	0