First observed as small brownish black lesions on older foliage. Larger spots show concentric rings in the dark portion. Sunscald on exposed fruit. Can cause severe defoliation, resulting in reduced fruit number and size. Older leaves are usually affected first.
Sanitary measures are critical.
A. solani survives on infected debris in the soil or on seed. High soil fertility reduces severity. Use disease resistant cultivars. Do not set diseased plants in the field. Infected seedlings are stunted.