Grapevine flavescence dorée phytoplasma
Significance: Symptoms of grapevine yellows have been observed in a few vineyards in Ticino (Switzerland) since the autumn of 2004. The causal agent was determined to be the Grapevine flavescence dorée phytoplasma. The principle insect vector for this phytoplasma, Scaphoideus titanus (a cicadellid previously introduced into Europe from North America and is sometimes called S. littoralis) were reported in Ticino and a few vineyards of the Geneva canton, but nowhere else in the grapevine producing regions of Switzerland. In Ticino, official control measures against the insect vector have been in place since 2001. All plants found infected by flavescence dorée are being destroyed (Stäubli, 2005 as cited in EPPO, 2006).
Issues of Concern: Grapevine flavescence dorée phytoplasm is not known to occur in North America and is a regulated pest by the NAPPO countries (see NAPPO Regional Standard for Phytosanitary Measures No. 15 October, 2002). Flavescence dorée phytoplasma is considered one of the most serious diseases known to affect grapevines. The disease was first reported in France in the 1950’s and has since spread elsewhere in Europe, where some commercial growers in France and Italy experienced heavy losses. The associated phytoplasma is transmitted from plant to plant by the leafhopper vector which is found in the United States and Canada. The presence of the vector in vineyards should be considered a threat as any introduction of grapevine latently infected with the phytoplasma could result in a serious epidemic. Under natural conditions the phytoplasma’s host range was thought to be restricted to species of Vitis, although recently it was also reported from Clematis vitalba growing near infected vineyards in Italy (Angelini et al., 2004).
Angelini, E., Squizzato, F., Lucchetta, G., and M. Borgo. 2004. Detection of a phytoplasma associated with grapevine flavescence dorée in Clematis vitalba. European Journal of Plant Pathology [Abstract] 110: 193-201.
EPPO Reporting Service (2006) No. 3 – 2006/055, from Stäubli A. (2005) Faits marquants dans la recherche 2004. La flavescence dorée de la vigne est apparue pour la première fois en Suisse. Revue Suisse de Viticulture, Arboriculture 37(3): 149.
INTERNET Servizio fitosanotario cantonale, Ticino, Bolletino fitosanitario No. 31 (2004-12-13). http://www.ti.ch/DFE/DE/SezA/temi_02/pubblicazioni/fito/2004/bof3104.pdf