Epidemiology of Flavescence Dorée in Vineyards in Northwestern Italy

Abstract

A serious outbreak of flavescence dorée (FD) was reported in Piemonte, northwestern Italy, in 1998, and since then, the disease has compromised the economy of this traditional wine-growing area, even following the application of compulsory insecticide treatments to control Scaphoideus titanus, the vector of the causal phytoplasma. Affected vines show severe symptoms, varying according to the cultivar, and are rogued to reduce disease spread. Following winter and pruning, a previously affected vine may appear symptomless and free of phytoplasmas in its aerial as well as its root system, even by nested-polymerase chain reaction assays. Such plants are considered to be "recovered". Since 1998 homogenous data on the incidence of newly infected, healthy, or recovered plants productivity, presence of vectors, and treatment schedules have been collected in seven severely affected vineyards of southern Piemonte for 5 years (1999 to 2003). Infectivity and recovery rates were also calculated each year. From 1999 to 2003, the average number of healthy plants decreased and the numbers of recovered plants and those with symptoms increased. Productivity of recovered vines, although lower than that of healthy ones, was always higher than that of vines with symptoms and was not influenced by the time elapsed from date of recovery. The relationships between the ln-transformed number of vectors trapped in the vineyards the previous year and the infection and the recovery rates were fitted by an exponential (R(2) = 0.95) and an asymptotic (R(2) = 0.93) model, respectively.

Survey and molecular detection of Bois noir in vineyards of the Czech Republic- Short communication

“…This almost 50% difference was significant (P = 0.05) in both years. A similar situation was described by Morone et al (2007) in northwestern Italian vineyards infected with Flavescence dorée. Yield losses in our work were estimated at 70% (data not shown).…”

Contrasting Susceptibilities to Flavescence Dorée in Vitis vinifera, Rootstocks and Wild Vitis Species

“…For example, the temperature influences the multiplication of FDp in plants (Salar et al, 2013) and there is a direct correlation between insect population and percentage of infected plants (Morone et al, 2007) and both factors can vary between observation sites. The number of plants is often low, as mandatory actions lead to uprooting of symptomatic plants.…”

“…However, it also depends on insect population sizes (Morone et al, 2007), as well as on transmission efficiency. One possible strategy for controlling the disease would be the planting of grapevine rootstocks and cultivars that are less susceptible to FDp transmission and/or FDp multiplication.…”

Scientific Opinion on pest categorisation of Grapevine Flavescence dorée

“…By drying inflorescences and bunches the phytoplasma can cause total yield loss and by reducing photosynthetic activity and nutrient transport it can also decrease grape quality. Infected plants can either die or recover, but they continue to be less productive (Credi, 1989;Morone et al, 2007).…”