Worldwide distribution. On tobacco, tomato, eggplant, and weeds. Common but minor fungal disease in Oceania.
Spots on lower mature leaves at first, moving up plant as season advances. Spots, circular, up to 15 mm diameter, brown, grey or tan, with dark borders, zoned. Centres papery, producing black masses of spores. Spots continue to develop after harvest.
Spread as airborne or soilborne spores; possibly, seedborne. Survival in trash other crops and weeds.
Cultural control: remove volunteers; check plants in nursery; avoid overlapping crops; weed; balanced applications of NPK (soil analyses needed); prune infected leaves as soon as spots seen; avoid overhead irrigation; collect, destroy debris after harvest; crop rotation.
Chemical control: use chlorothalonil, copper, or mancozeb.