Lower leaves are attacked first. The leaf tissue around the spots turns yellow. When the disease is severe, leaves fall off. If not controlled in the leaf stage, stems and fruit may also be infected. Fruits will develop dark leathery spots near the stem end.
Early blight is favored by rainy periods with warmer temperatures.
Under moist conditions, these blotches enlarge rapidly. A white, fuzzy growth of fungus may also be seen on the undersides of the leaves. Infected plants eventually wither and die. Elongated black cankers develop on the stem and leaf petioles. A whitish mold may cover the infected tissue during moist weather.