Observations on the Fungi Associated with Esca and on Spatial Distribution of Esca-Symptomatic Plants in Apulian (Italy) Vineyards

The paper reports the results of observations on the fungi associated with deteriorated wood of esca affected vines and the spatial distribution of diseased plants in 21 vineyards located in Apulia (Southern Italy). Examination of over 43,000 plants revealed that the incidence of plants showing symptoms of esca was 12% (5-18%) in vineyards younger than 10 years and 22% (4-54%) in older ones. The most common deteriorations of the wood were a white rot of soft consistency and a dark brown discoloration of a hard consistency including longitudinal black streaks. Mycological analysis was carried out on 554 diseased vines from 5 vineyards. Phellinus sp. was frequently isolated from white rot, whereas Phaeoacremonium spp., Botryosphaeria spp. and Eutypa lata were more often isolated from dark brown tissues. Preliminary observations of maps of plants with symptoms of esca seem to indicate a tendency to aggregation, especially in young vineyards