Scab may occur on leaves, fruit, stems and green twigs but infections of the leaves and fruit are most common and obvious.
Infection on leaves first appears on the lower side. Young lesions are velvety brown to olive green with indistinct margins and later turn dark brown to black. Lesions on older leaves are typically raised, dark green to gray-brown with distinct margins, and cause cupping on the underside of the leaf. Leaves that are heavily infected with scab will curl, shrivel and fall from the tree. On fruits, small black spots develop at first and later become brown, corky and scabby. Heavily infected fruit becomes deformed and cracked when infected at an immature stage.