Following the notification of grape vine red blotch virus (GRBV) detection in Western Australia in July 2022, Autumn surveillance and testing has been conducted in several States returning encouraging results. The very low number of positive results indicate that spread of GRBV is likely to be low. With that in mind, we remain committed to taking measures to ensure that there is no further spread of GRBV within Australia. The primary risk of distribution is through infected propagation material so we are continuing to investigate management options for addressing this with or without regulatory support. It is our desire that GRBV might eventually be assumed extinct from Australia through natural attrition. Regardless of the pending decision as to whether the virus is technically feasible to eradicate, we intend to continue to advocate to government to continue testing at the national border to prevent future introductions of the virus.
As the virus is often present alongside other viruses, it has been difficult to confirm the extent to which infected vines in Australia display symptoms of GRBV. Experiences overseas highlight the significant potential damage bill for infected vineyards. In parts of California, economic modelling has shown that the virus could cost up to USD68, 548/Ha over 25 years (based on a scenario where poor fruit quality means full vineyard replacement is the most economical management strategy). We encourage growers who observe GRBV symptoms, or indeed any other virus like symptoms, in their vineyards to consider a complete virus screen which includes GRBV. The AWRI Fact sheet has further information regarding typical virus symptoms and where to send samples for testing.
We would like to acknowledge the organisations that have dedicated staff and resources to better understanding GRBV in Australia over the past year. These include Vinehealth Australia, Wine Australia, state and national Vine Improvement Associations, Vine Industry Nurseries Association and AWRI. Additionally, our praise goes to the virologists at Agriculture Victoria – Crop Health Services and DPIRD Diagnostic Laboratory Services in Western Australia whose tireless efforts have allowed us to rapidly improve our understanding of GRBV and optimise the accuracy of testing and sampling methods for the benefit of the wine sector.
