(Mycosphaerella brassicicola)
Credits:Biovision-Infonet
Ring spots are small, purple spots surrounded by a ring of water-soaked tissue on leaves which mature to brown spots with olive green borders 1-2 cm wide. The spots may develop numerous fruiting bodies which give them a black appearance or develop a concentric pattern. Heavily infected leaves may dry up and curl inwards. Ring spot requires cool, moist conditions to develop.
What to do:
- Avoid planting cabbage in previously infected areas
- Rotate crop with non-brassica crops
- Sanitize farm tools and equipment regularly