Early Blight (fungus - Alternaria solani): Mycelium and spores of Atlernaria survive in crop residue. Frequent rain and heavy dews are needed for heavy infection. First symptoms are oval to angular dark-brown to black target spots on the leaves. Spots often have a yellow area around them. The lowest or oldest leaves are infected first. Leaves are often killed and yields are reduced. Tuber infection may occur with brown-black sunken spots, from to inch in diameter. The underlying tissue shows a brown, corky, dry rot more than inch deep. Control with 2 year rotation, good fertility and foliar fungicides.
