Leaf blotch

Leaf blotch - Briosia ampelophaga
Annemiek Schilder, MSU Plant Pathology

Leaf blotch is present throughout the eastern United States. It can affect many types of grapes but is most often found on leaves of American rootstock cultivars. Leaf lesions appear after mid-season. Lesion size ranges from 1/25 to 2 inches (1 to 50 mm). Small lesions have dark margins, and large lesions have light-colored, zonate rings. Stalked fruiting structures are produced within 3 to 4 days of the appearance of the lesion, usually on the lower leaf surface. The fungus may also sporulate on overripe berries. The fungus overwinters in infected plant debris.


Photo: http://www.APSnet.org

Additional information

Search MSU Fruit CAT Alert newsletter for articles.
MSU Diagnostic Services
Special grape disease problems and controls (from Michigan Fruit Management Guide)

Site map About us Copyright/Linking

Funding for this web site provided by Project GREEEN, American Farmland Trust, EPA Region 5's Strategic Agricultural Initiative program, The National Foundation for IPM Education, the Center for Agricultural Partnerships and the MSU Integrated Pest Management Program
in collaboration with MSU Extension and the Michigan Agricultural Experiment Station.
Updated 11/14/07 Contact: J.N. Landis.