The recent detections of grapevine berry inner necrosis virus (GINV) in Queensland, Victoria, South Australia and New South Wales have raised some questions about its economic significance to the industry. The degree of uncertainty reflects the recency of its discovery, and the limited understanding of its distribution, epidemiology and potential effects under Australian growing conditions. Responding to newly detected grapevine viruses is inherently complex, especially given that infections may remain undetected for many years. Understanding virus distribution requires tracing historical movements of virus-infected vines back to their origin and then forward tracing subsequent distribution of infected material. This is not only challenging, but for many viruses, further complicated by the fact that vectors can also facilitate natural spread. The fact that GINV can be spread by mites, means it is not likely to be possible to fully understand the extent of its distribution. Recent diagnostic sampling across New South Wales, Queensland, South Australia and Victoria resulted in an approximately 27% detection rate, however it is important to highlight that this percentage is derived from directed sampling of specific vines rather than a randomised baseline survey, and so should not be interpreted as a national or regional infection rate.
A well-informed approach to managing viral pathogens across the viticulture industry is critical, as pathogenic virus infections directly impair vine physiology, reduce overall vineyard yield, compromise grape and wine quality parameters (such as sugar accumulation and acid balance), and shorten the productive lifespan of the vine (Wine Australia Virus Management Overview). However, not all virus types are pathogenic or carry a demonstrable economic impact. Some virus types, such as grapevine rupestris stem pitting-associated virus (RSPaV), are found in almost all grapevines, have virtually zero economic impact in Australia, are not considered detrimental, and are therefore no longer routinely tested for by nurseries and vine improvement groups meaning healthy, high-performing vines may still harbour this virus (PMC Australian Vineyard Virus Report).
In contrast to the uncertainty surrounding GINV, the viticulture industry has long managed other significant viral pathogens with well-documented economic impacts, such as grapevine leafroll-associated viruses (GLRaVs). Endemic to Australia, viruses like GLRaV-1 and GLRaV-3 are known to cause leafroll disease, which results in reduced vine vigour, yield loss, and delayed or variable fruit ripening that directly impairs wine quality. While GINV is spread by mites, GLRaV-1 and GLRaV-3 are primarily vectored by mealybugs and scale insects. Both, however, underscore the vital importance of utilizing certified virus-tested propagation material, maintaining rigorous vineyard hygiene, and implementing targeted vector management strategies to protect established vineyard assets.
Other virus types like grapevine Pinot gris virus (GPGV) have been the subject of research and debate since the virus was characterised globally in 2012 and detected in Australia in 2016 (Wine Australia GPGV Overview). While there have been efforts to limit the spread of this virus, the particular biology of the virus and its mite vector (Colomerus vitis) has meant that this virus has likely spread to almost all viticultural regions in a relatively short amount of time (apart from Western Australia, which maintains strict quarantine controls). At this point, despite being widespread across Australia, very few symptoms have been observed in wine grape varieties, which points to GPGV potentially having very limited economic impact and, at worst, a localised impact on a small number of sensitive varieties (PMC Study on GPGV Diversity in Australia).
