Hard, scab-like spots on the infected fruit are characteristic symptoms of nailhead spot. The spots are dark brown and usually small, and the discoloration extends beneath each spot into the flesh of the fruit. Like early blight, it causes leaf defoliation.
Large black leathery sunken areas are produced on the fruit. These areas generally start around the fruit pedicel or in some small wound or crack, rapidly becoming enlarged. In overhead-irrigated crops, infections occur in the field during the summer Summer sprays must therefore be applied to provide protection. In most seasons, however, large amounts of fruit rot only in late August and September.
