14.6 Cercospora (Ascomycota)

Many species of this genus cause plant diseases, mostly of the ‘leaf spot’ variety. Leaf spots are rounded blemishes occurring on the leaves of the infected plants; a typical spot has a defined edge with a darker border and a central zone varying from yellow to brown. Numerous spots can merge together and the larger areas can be called blights or blotch diseases.

Cercospora is not the only cause of leaf spot diseases but it causes disease on: alfalfa, asparagus, banana, brassicas, Cannabis, carrot, celery, cereals, coffee, cucumber, figs, geraniums, grapes, grasses, hazel, hops, lentil, lettuce, mango, millet, orchids, papaya, peanut, pear, peas, peppers, potato, roses, sorghum, soybean, spinach, strawberry, sugar beet, sugarcane (the spots merge into stripes; so the disease is called ‘black stripe’), sycamore, tobacco, watermelon, and many wild plants and ornamentals.

Cercospora beticola is the most destructive leaf disease of sugar beet worldwide; the disease reduces yield and quality of sugarbeet and the need to use fungicide to control leaf spot disease adds significantly to the cost of production. C. beticola overwinters as stromata in infected crop residues and spores produced on these are the prime source of infection of the leaves of the next season’s crop (Khan et al., 2008).

Resources Box

More information about plant pathogens

More information about plant pathogens can be found in the British Society of Plant Pathology’s Pathogen profiles, which are a regular feature in the journal Molecular Plant Pathology and BSPPWeb providing brief overviews of the latest research on particular pathogens.

Profile summaries are available at http://www.bspp.org.uk/ [go to <Publications> and then click on <Molecular Pl. Pathology>]
Full articles can be downloaded from the Blackwell Molecular Plant Pathology web site [http://www.blackwellpublishing.com/journal.asp?ref=1464-6722&site=1]

We would also strongly recommend a visit to the teaching materials on the website maintained by the Department of Plant Pathology of the University of Wisconsin-Madison, USA at this URL:

http://www.plantpath.wisc.edu/PDDCEducation/EducationIndex.htm

Updated December 17, 2016