University of Florida

Black Shoulder

Cause

Unknown; Alternaria sp. have been implicated.

Affects

Shoulders of tomato fruit.

Symptoms

Sunken, irregularly-sized areas on fruit shoulders, appearing dark gray to blue-black, often with a tissue collapse.

Favorable Conditions

Cool weather during or before harvest of green fruit. Has been observed to be correlated with cold front rains close to harvest.

Black Shoulder Picture

fruit showing black shoulder
Image # 140
Black shoulder-
dark gray to brown to blue-black irregular sunken lesions on fruit shoulders.