Impact of biotic and abiotic factors on the development of Esca decline disease

Abstract: The aim of researches performed by our group is to determine which internal andexternal factors have a key influence on grapevine wood diseases, especially on Esca. Therelationship between Esca leaf symptoms, the size of inner necrosis, the fungal endophytesassociated with the disease and the whole microflora that can be detected from the grapevinewood, is discussed. Recent studies on leaf symptom development showed that summertemperature conditions likely play a major role in the expression of Esca symptoms. Culturalfactors, like plant vigor or type of soils, also have presumably a significant influence. Severalevidences suggest that other abiotic factors linked to the training systems (e.g. forms with veryshort cordons) or to pruning decisions (e.g. winter hand pruning characteristic of the moderngrape-growing training systems) have also to be taken into account, alone or combined with otherfactors. Whole data indicate that Esca is a multi-factor disease and that many complexpathological scenarios could explain the grapevine trunk disease expression. A control strategy,mainly based on cultural measures to avoid a too early development of inner necrosis, isproposed.