Southern leaf blight

Symptom

Attacks leaves, husks, stalks, leaf sheaths, shanks, ears, and cobs. Stalk and leaf infections initially appear as purple spots that develop tan-gray centers. Lesions are  rectangular to elliptical in shape, and have reddish-brown margins. Loss of leaf area results in reduced photosynthesis, lowering yield potential and increasing risk of stalk rots. Ear infections result in a gray-black lesion on the husk that extends into the kernels, appearing as a black felt-like mold. Ear and cob rots may also occur due to this fungus.