Cabbage light leaf spot, frog-eye leaf spot
Cercospora brassicicola
Worldwide. In tropical and sub-tropical countries. It is recorded from Australia, Niue, Papua New Guinea, Solomon Islands, and Vanuatu.
Plants in the cabbage family (Brassicaeae), particularly, Chinese cabbage, cauliflower, turnip, mustard, and to a lesser extent cabbage.
Leaf spots round to angular, up to 8 mm diameter, pale brown or white with a dark brown margin (Photos 1&2).
Spread is in rain and wind, and survival is in trash, on volunteer plants, weeds and seed. In general, it is a disease favoured by wet conditions, and cool temperatures, less than 20°C.
Although a common disease, its impact is low as it is mainly a disease of mature leaves. Only occasionally does defoliation occurs.
Look for the round to angular, pale brown, gray or white spots, with a dark border, less than 1 cm across.
CULTURAL CONTROL
Before planting:
During growth:
After harvest:
CHEMICAL CONTROL
AUTHORS Grahame Jackson & Eric McKenzie
Information from Smith S (2012) Diseases of turnip and mustard greens, Division of Agriculture, Research & Extension, University of Arkansas System. (https://www.uaex.edu/publications/PDF/FSA-7549.pdf). Photo 1 Clemson - USDA Cooperative Extension Slide Series, Bugwood.org. Photo 2 David B. Langston, University of Georgia, Bugwood.org.
Produced with support from the Australian Centre for International Agricultural Research under project PC/2010/090: Strengthening integrated crop management research in the Pacific Islands in support of sustainable intensification of high-value crop production, implemented by the University of Queensland and the Secretariat of the Pacific Community.
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