Stemphylium floridanum and S. botryosum
Small brownish-black specks first appear on undersides of leaves. These later develop into larger necrotic areas, and the tissue often falls out, leaving a shot hole type appearance. Spots may be surrounded by a yellow halo. Yellowing, leaf drop, and defoliation may occur in severe cases.
The fungus can survive from year to year on Solanaceous weeds, so weed control is important. Leaf moisture from rains or dew increases disease severity. Fungicides may be used as recommended. Many commercial varieties are resistant.