Increasing evidence that Eutypa dieback of grapevines is widespread in New South Wales

Eutypa dieback, caused by the fungus Eutypa lata is a serious disease of grapevines that affects vineyard productivity and longevity. Between November 2006 and April 2008, grapevines displaying foliar symptoms typical of Eutypa dieback or evidence of Botryosphaeria canker such as dead spurs, cankers, and bleached or discolored tissue, were surveyed from 75 vineyards throughout New South Wales, Australia. Wood samples were taken from 1835 vines, surface sterilised and transferred to potato dextrose agar (PDA). Samples were incubated at 25ºC and monitored for the appearance of fungi. Eutypa lata was tentatively identified based on cultural and conidial morphology. Molecular identification confirmed the identity of Eutypa lata and Cryptovalsa ampelina, a diatrypaceous ascomycete from the same family, based on amplification of a species-specific marker and sequencing and comparison of ribosomal DNA internal transcribed spacer (ITS) sequences. These surveys have shown that Eutypa dieback is more widespread in New South Wales than first thought, and may be increasing in prominence in the cooler climate regions where lower temperatures and higher rainfall favor its growth. Vigilant monitoring, protection of pruning wounds from infection, and removal of dead infected wood from the vineyard remain the best methods of managing these diseases.