Bacterial Ring Rot
Clavibacter michiganensis subsp. sepedonicus
Overview
A serious quarantine disease of potatoes causing wilting, yellowing, and a characteristic ring of decay in tuber vascular tissue. Highly contagious through contaminated equipment and seed.
Symptoms
Wilting and yellowing of leaves, often on one side of the plant. Interveinal chlorosis. When tubers are cut, a creamy, cheese-like bacterial exudate can be squeezed from the vascular ring. Tuber rot in storage.
Environmental Conditions
Variable
Prevention
Use certified disease-free seed potatoes. Disinfect all cutting and planting equipment. Do not save seed from infected lots. Plant whole seed pieces when possible.
Management
Zero tolerance quarantine disease. Destroy all infected lots. Disinfect all equipment thoroughly. Do not replant potatoes in infested fields for 3+ years. Report to agricultural authorities.