There are in excess of 80 recognised virus and virus-like diseases of grapevines worldwide. Many have obvious detrimental effects on vine health, productivity and grape quality, shortening the productive life of the vineyard. Viruses can be spread by insect vectors, soil-borne nematode vectors or by using infected cuttings during standard grafting and propagation practices. Symptomless infections often occur and these infected grapevines may act as a reservoir of infection for sensitive varieties.
There is no known cure for grapevines infected with virus. Viruses can spread quickly from infected to uninfected vines in the presence of vectors. Management practices include removal or rogueing of infected vines (based on visual symptoms and confirmation with molecular diagnosis), adequate control of insect vectors in the vineyard and using planting material which is certified high health and free of infection.
Discolouration in vine leaves caused by grapevine leafroll-associated viruses
There are 12 grapevine viruses endemic to Australia. The main viruses of economic importance are the grapevine leafroll-associated viruses GLRaV-1 and GLRaV-3, and grapevine virus A (GVA), which causes Shiraz Disease. Leafroll is named for the distinct foliar symptoms that are observed on infected grapevines, often in association with leaf discolouration in autumn (see above). Vines with leafroll disease have reduced vigour, yield loss and delayed or variable fruit ripening, impacting on timing of harvest and grape quality.
Our factsheet on grapevine leafroll associated viruses provides detailed information on the symptoms and management. Click here to download the PDF
Shiraz Disease has thus far only been reported in South Africa and Australia. As the name suggests, the variety Shiraz is particularly sensitive to GVA infection, which causes reduced spring growth, yield loss and affects grape quality in infected vines. It can have a significant economic impact on affected vineyard businesses. GVA is often found in association with other viral infections.
The ‘rugose wood complex’ is a group of diseases which includes GVA and is characterised by modifications of the woody cylinder of the vine. The diseases are of major importance to viticulture worldwide, but have less of an impact in Australia despite being widespread. The five rugose wood diseases observed in Australia are rupestris stem pitting, Kober stem grooving, corky bark, N33 stem grooving and corky wood.
Our factsheet on rugose wood provides detailed information on the symptoms, associated viruses and management. Click here to download the PDF.
Grapevine Pinot Gris Virus
Grapevine Pinot Gris Virus (GPGV) was first detected in Australian vineyards in 2016 and has since been found to infect multiple grapevine varieties. It can be associated with leaf mottling symptoms, most evident in spring, but is also symptomless. The effects of GPGV on grapevine growth, yield and fruit quality are currently unclear.
We have further information here on GPGV, its symptoms, how it spreads and management of the virus.
Virus testing is offered by three commercial laboratories in Australia:
Further information on specific grapevine viruses can be found via the links to the right of this page.
Monitoring for grapevine viruses in established vineyards
In 2019, the AWRI hosted a webinar with Dr Fiona Constable (Agriculture Victoria), Dr Nuredin Habili (AWRI) and Tony Hoare (AWRI) discussing grapevine viruses in Australia, covering:
- What are the symptoms that delineate viruses from other virus-like issues?
- When is the best time to monitor for these symptoms during the growing season?
- What options are available to confirm the presence and severity of virus in a vineyard and what is the next step once a diagnosis is confirmed?
Post-harvest, pruning and spring are the ideal times for detecting virus in vineyards and the webinar provides information and tools required for an accurate assessment.
Rootstock remnants, viruses and re-planting challenges
In October 2020, The AWRI hosted a panel featuring Rob Sutherland (De Bortoli Wines), Dr Vaughn Bell (The New Zealand Institute for Plant and Food Research Limited) and Dr Fiona Constable (Department of Jobs, Precincts and Regions, Victoria) that discussed a range of topics related to vineyard viruses, in both Australia and New Zealand, as well as the experiences of Yarra Valley growers when considering replanting vineyards.
Related articles about grapevine viruses
Trans-Tasman project aims to stop viral pathogens in their tracks | 11 June 2021
Clock ticking down for grapevine leaf-roll virus diagnostic tool | 7 June 2019
Play it safe with GPGV | 8 February 2019