Symptoms of silver scurf usually appear on the stem end of tubers as small light brown or grayish leathery spots and may enlarge to cover most of the tuber surface. Lesions have a shiny appearance that is more pronounced when tubers are wet. Margins of young lesions are frequently dark brown and sooty from spore production. Microscopic examination reveals tiny "Christmastree-like" spore structures formed by the production of conidiophores with conidia (spores) attached.
Black dot tuber lesions have a similar appearance but do not have dark, sooty margins and usually contain numerous tiny black dots (sclerotia) that have small microscopic spines. The two diseases can be present on the same tuber. Silver scurf is most noticeable on red‑skinned and other smooth-skinned cultivars but can cause substantial damage on russet cultivars. Smooth skin cultivars can be severely infected and rendered unsalable at harvest whereas all cultivars can be substantially damaged during storage. Affected tubers are more susceptible to decay and shrinkage from water loss during storage.