Fanleaf degeneration

Fanleaf degeneration - Grapevine fanleaf virus
Annemiek Schilder, MSU Plant Pathology

Fanleaf degeneration affects vinifera cultivars. It is characterized by fan-shaped leaves with toothed margins, proliferation of shoots, short internodes and zigzag growth. Foliar symptoms appear early in the spring and persist through the growing season. Sometimes leaves show a bright yellow mosaic or yellow vein banding with little or no malformation. Fruit clusters are small with poor fruit set, irregular ripening and shot berries. The causal virus is spread by dagger nematodes and planting material. The virus is not transmitted through seeds and has no natural weed hosts. Roots from infected vines can be a source of infection even after the mother plant has been removed.


	Leaf with fanleaf symptoms (left) compared with a healthy leaf (right).
Fanleaf degeneration on fruit cluster.

Additional information

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Special grape disease problems and controls (from Michigan Fruit Management Guide) (Download Adobe Acrobat Reader to view PDF files)

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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 12/20/07 Contact: J.N. Landis.