- Worldwide distribution. In sub-tropics and temperate areas. On cabbage and other brassicas. An important disease.
- Spots, angular, dark with light centres up to 20 mm, with yellow halos, and black spore bodies. Early death of leaves; layers of leaves removed in storage.
- Spread as spores, blown in wind and rain.
- Cultural control: nursery far from production areas; nursery hygiene, soilless or pasteurised soil; 2-3-year crop rotation; avoid overlapping crops; weed; collect and burn trash after harvest.
- Chemical control: chlorothalonil, mancozeb, copper. Treat seed: thiram or hot water (50°C for 30 mins.).
