A newly completed project sets out a plan for Australian grapegrowers to better manage Grapevine leafroll disease (GLD) and Shiraz disease in vineyards.
The project, funded by Wine Australia, did not embark on any new research. Instead, the focus was on evaluating current knowledge from within Australia and overseas of how to respond to the target viruses.
The best practice guide, Grapevine leafroll disease and Shiraz disease: interim recommendations for management in Australian vineyards – authored by international expert Dr Vaughn Bell from the New Zealand Institute for Plant and Food Research – contains the latest research information. It details a multi-tactic, whole-of-industry response, focussed on preventative measures and early intervention to reduce and contain virus spread.
Key recommendations from the guide highlight the importance of:
- early detection of virus infection in grapevines
- identifying and removing diseased grapevines, and
- monitoring and managing the insects responsible for the spread of the viruses within and between vineyards.
The guide also reinforces the importance of sourcing vines certified as virus-free when planting.
New Zealand Winegrowers, the national industry body in NZ, began tackling Grapevine leafroll disease (GLD) in the early 2000s and Dr Bell said that in the years following, growers gained considerable experience in implementing an in-vineyard response to these economically important viruses.
The recommendations in the guide are based on the NZ experience and current Australian knowledge. There are sections on visual symptom identification, effective roguing, the importance of vectors and their management and best practice testing procedures, supported by decision support trees.
“Many of the ideas and responses described in the Wine Australia project report have been tried and tested in New Zealand, and while differences in grape growing between countries are acknowledged, many virus management principles are similar and can be applied in Australian vineyards with confidence,” Dr Bell said.
Dr Bell said some of the concepts proposed in the Australian guide will be new to many growers, so implementing all aspects of the proposed management plan may be challenging. However, he stressed the importance of initial action.
“A good starting point is to at least begin assessing virus incidence across the vineyard. A good understanding of virus incidence in different single variety blocks is the basis for other decisions.”
More detail on the Guide can be found here.