White leaf spot

White leaf spot (Pseudocercosporella spp) is a minor foliar disease of brassicas (P. capsellae) and legumes (P. albida). The most susceptible varieties are chinese cabbage, swede and turnip with fewer reports of infection in Brassica oleracea species (broccoli, cabbage, cauliflower etc.

Brassicas
The primary symptoms are leaf spots that begin small, 2-3mm, grey-green in colour and circular. As the condition develops these lesions will expand up to 10-12mm, turn light tan to white and remain circular. Dark streaks and speckling are sometimes visible within the leaf spots.

Treatment
Control methods are rarely needed. Plow in infected crop residues after harvest.

Prevention
Do not plant susceptible crops in infected sites for at least 1 year.