Causal Agent:
Colletotrichum coccodes
Biology:
Pathogen of potato and relatives such as nightshades, tomato, and pepper. Overwinters in soil on plant debris or non-harvested tubers. Affected tubers occur consistently in some fields.
Dispersal:
Seed tubers are commonly infected, and provide the most common way that black dot moves from field to field. Once soils are infested, they remain infested for some time.
Management:
Further Reading:
Pacific Northwest Pest Management Handbooks