Kangaroo Island grapevine trunk disease survey

The survey confirmed that grapevine trunk diseases occur in vineyards on Kangaroo Island, with botryosphaeria dieback detected in most vineyards and eutypa dieback in three of the 12 vineyards assessed. The severity of symptoms was low but based on experience in older regions in South Australia, without intervention, cordons and trunks will continue to die-back and vines will become unproductive and die. These results serve as a timely early warning to grapegrowers on Kangaroo Island, proving impetus to manage trunk diseases to lessen the impact on production. Recommendations were provided to Kangaroo Island growers at a workshop, including cutting out wood infected with trunk disease pathogens and preventing any new infection by protecting pruning wounds. Information was also provided on the latest recommendations for managing the foliar diseases powdery and downy mildew along with botrytis bunch rot.