Grapevine Trunk Disease Review

Grapevine trunk disease is a high profile condition of the vine which appears to be increasing in incidence and severity globally. Major pathogens include Botryosphaeria spp., Cylindrocarpon spp., Eutypa lata, Phaeomoniella chlamydosporum, Phaeoacremonium aleophilum, Phomopsis viticola and others. Symptoms are variable and inconsistent but generally involve wood & leaf necrosis as well as poor growth and/or establishment, and in very acute cases, vine death. Increasingly, multiple pathogens are found in single vines, casting doubt on traditional definitions of discreet diseases, i.e. ‘Esca’ or ‘Eutypa’ and implying instead a range of interchangeable symptoms caused by a range of pathogens. Interaction between these pathogens and their environment appears to be complex and sometimes specific to species and location, with environmental stress thought to play an important role. Control measures are limited to preventing spread and the severe surgery of infected or entire vines. Vectors for infection have the potential to be varied, but pruning wounds appear to be the principle point of entry. Pruning wound treatments can reduce infection by limiting mycelial growth on open wounds but are subject to variable results and local regulations on the use and availability of fungicides. Further cultural methods as part of viticultural best practice (i.e. site selection) are also important to managing these conditions.