- Widespread distribution. On all yam species, but most common on Asiatic yam (or lesser yam), Dioscorea esculenta. A minor disease, unlikely to affect yield.
- Leaf spots, circular or irregular, up to 10 mm diameter, tan or grey, merging, with dark brown or black borders. Fruitbodies can be seen as black pin points in the spots.
- Spread occurs when spores ooze from fruitbodies during wet weather and splashed by rain or carried by wind.
- Cultural control: collect debris (vines and leaves) and destroy after harvest; 2-3 year crop rotations; test varieties for differences in tolerance.
- Chemical control: unlikely to be needed, but if required use chlorothalonil, copper, or mancozeb.