Investigation into the occurrence of esca-associated fungi in cuttings and bench-grafted vines

Rootstocks, scions, certified virus-free grafted plants and 1-year old plants were studied to determine the incidence of wood discoloration and the occurrence of fungi associated with esca. On cuttings very little discoloration was observed and fungal infection was negligible. The majority of grafts and vines showed blackening and harboured a variety of fungi, mainly Phaeoacremonium spp., with Phaeomoniella chlamydospora in second place. The presence of these fungi as endophytes requires further investigation to determine the conditions under which they become pathogenic and to determine when contamination of vine material occurs during nursery operations.