Flavescence dorée

Flavescence dorée
Symptoms on leaves
Common names	flavescence dorée of grapevine
Causal agents	Candidatus Phytoplasma vitis
Hosts	Vine
Vectors	Scaphoideus titanus
EPPO Code	PHYP64
Distribution	Europe (France, Switzerland, Germany, Italy), United States, Australia
Treatment	uprooting of infected plants

Flavescence dorée (from French "Flavescence" : yellowing and "dorée" : golden) is a phytoplasma disease of the vine with the potential to threaten vineyards. The bacterial agent has recently been named Candidatus Phytoplasma vitis, and its vector is the leafhopper, Scaphoideus titanus. Infection may kill young vines and greatly reduce the productivity of old vines.^[1] It is classified as a phytoplasma disease belonging to the group generically termed grapevine yellows.^[2] Occurrences are in sporadic epidemics, and varieties vary in their sensitivity to it.

There is no cure at the moment and the way to manage its spread is by uprooting infected plants and by using selective insecticides in an area-wide pest management approach in order to reduce the hemipteran vectors.^{[citation needed]}

Symptoms[]

Leaves become red or yellow depending on variety. Twigs stay soft. There is no cold hardening.

Tests[]

The Phytoplasma bacterium species responsible for the disease cannot be cultured in vitro in cell-free media. Quantitative PCR can be used for the early detection of the bacterium in the plant.

Biology[]

Ca. Phytoplasma vitis is part of the 16SrV group (group name: Elm yellows) in the Phytoplasma taxonomy.

History[]

Flavescence dorée first appeared in 1949 in the Armagnac region of south west France.^[2] Its insect vector, S. titanus, was originally native to the Eastern United States and Canada and is believed to have been introduced to Europe either during World War II or earlier with American rootstock brought in to fight off phylloxera. Spreading steadily throughout France, it had by 1987 reached the wine growing regions of Cognac, Languedoc and northern and southern Rhône, and by 1992 the Loire Valley, and Bordeaux.^[1] Variants of the disease are found in Switzerland, Germany, Italy, New York state, and Australia.

• 

  Symptoms on German variety Scheurebe

• 

  Symptoms on German variety Scheurebe

• 

  Symptoms on German variety Scheurebe

See also[]

• List of grape diseases
• black wood of grapevine or "Stolbur" or "Bois noir", another vine disease due to a Phytoplasma species

References[]

External links[]

• Documentation at inra.fr