Flavescence doree

Flavescence dorée - Grapevine flavescence dorée phytoplasma
Annemiek Schilder, MSU Plant Pathology

Flavescence dorée infects only vinifera grapes and interspecific hybrids. Labrusca cultivars are resistant. Symptoms usually appear the year after infection and either get progressively worse until the vine dies or disappear in an apparent recovery. Symptoms include delayed or no bud break and progressively shortened internodes. In summer, vines take on a weeping posture, and shoots become rubbery and fail to lignify. Characteristic black pustules may be seen in longitudinal rows near the bases of shoots. The leaves have golden yellow or reddish patches and curl downward. Growing points become necrotic, and flowers and fruit clusters shrivel up and fall. The pathogen overwinters in infected canes and is spread by a leafhopper. Symptoms may resemble those of certain virus diseases or potato leafhopper damage.


Photo: http://www.APSnet.org	Black pustules in rows. 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)

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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 11/01/07 Contact: J.N. Landis.