Fungi associated with esca and young grapevine decline in Greece.

Abstract

In the period 1998–2001 significant numbers of vine samples of different varieties, grafted onto different rootstocks, ready for out-planting or planted and declined a few months or years later, were collected or sent to our laboratory to investigate the presence of phytopathogenic fungi. Three hundred eighty rooted cuttings ready for outplanting, 1250 young vines planted and exhibiting decline symptoms in the first year of establishment, 82 vines two to nine years old and 27 old vines exhibiting the classical esca symptoms were examined. Isolations yielded the fungi Phaeomoniella chlamydospora, Fomitiporia punctata and Stereum hirsutum, as well as other fungi of the genera Phaeoacremonium, Cylindrocarpon and Botryosphaeria. The low incidence of these fungi isolated in a low percentage of samples suggested that they could not by themselves be the cause of young grapevine decline. Abiotic causes, such as lesions from improperly healed rootstock disbudding sites and graft unions made in the nursery, as well as improper storage and transportation conditions of the propagated material must also have played a role and made the decline more acute. The occurrence of the isolated fungi as endophytes and their role in the outbreak of grapevine decline remain to be investigated.