Australian Grape & Wine recently released a biosecurity alert notifying members that Grapevine Red Blotch Virus (GRBV) has been detected for the first time in Australia and is known to be in Victoria, South Australia and Western Australia. Trace forward activities are in progress to confirm the extent of spread. Trace back activities show that GRBV likely entered Australia in infected propagation material as early as 1985, well before the virus was discovered or a diagnostic test developed.
The virus was first found in table grape variety Perle de Csaba, in a WA facility. The infected vines were traced back to an established collection at a research facility in Victoria where they were originally sourced from. Grapevines of the same variety at that sight, have since been tested and are suspected to be positive. Tracing from the research facility in Victoria has identified the Perle de Csaba is also present in germplasm collections in South Australia and New South Wales. Samples taken from Perle de Csaba, Brachetto, Malbec and Harselevulu have returned positive results for GRBV in South Australia and Western Australia. Additional varieties that have tested positive in WA are Pinot Noir, Kadarka, Savagnin, Chardonnay and Merlot.
Grapegrowers should always purchase planting material from an accredited nursery and/or request information regarding the health status of the vines. There are several other viruses of grapevines that have the potential to impact grapevines so this approach has always been advisable.
As this virus was previously assumed to be exotic, suppliers might not have this on their list of virus screens. To better understand the risk, known variety and clone combinations that have tested positive in germplasm collections and some source blocks are listed on the WA Department of Primary Industries and Regional Development website.
Fortunately, it is thought that any vectors responsible for spread of the virus in Australia are currently relatively ineffective compared to vectors in the USA where the virus has reportedly caused significant economic losses in some regions. GRBV (with vector) is a High Priority Plant Pest for the viticulture industry.
The Consultative Committee on Emergency Plant Pests has been notified of the detections and is considering its status under the Emergency Plant Pest Response Deed, and whether it would be technically feasible to eradicate. Australian Grape and Wine represents the winegrape industry on this committee and will ensure members remain informed with all the latest information.
More information regarding the detection and a list of State based contacts is available here.
Vinehealth Australia have also recently released a Q and A document that is available via their website.