BUSINESS GINV

What is Grapevine berry inner necrosis virus and why it matters?

GINV virus (Trichovirus necroacini) causes grapevine berry inner necrosis disease. The virus only affects grapevines (Vitis spp.), including table grapes, wine grapes, and rootstock varieties. Infected vines may show reduced productivity and compromised fruit quality. So far in Australia GINV has only been reported from table grape varieties.

What to look for

Symptoms vary depending on the grapevine species and cultivar. Infected grapevines may take years to express symptoms. The severity of the disease may be affected by environmental conditions and plant nutrition and health. Effects of the disease include:

• Plant development — low vigour, delayed bud break, short internodes, and internal browning of the shoots.

• Leaves — deformation, yellowing patterns (chlorotic mottling), rings, and mosaic patterns.

• Fruit — delay of ripening and small berries with internal necrosis (tissue decay) and external discoloration of the bunches.

How does it survive and spread?

GINV spreads primarily through infected propagation material, including cuttings, grafts, and rootstocks.

Short internodes and restricted shoot growth associated with GINV.

Blister-like galls on the upper leaf surface.

Photography

Bugwood org

Internal browning of stems.

Photography

Roshni Rohra, Agriculture Victoria

White, fuzzy, felt-like patches (erinea) on the lower surface.

Photography

Wikimedia Commons

Monitoring

Monitoring pests and diseases in grapevines grown in home gardens, community gardens, and small landholdings plays an important role in protecting local vineyards and WA’s grape and horticultural industries.

Symptoms of grape leaf blister mite (Colomerus vitis) — a known vector of GINV.

It can also be transmitted by the erineum mite (Colomerus vitis) commonly known as the grape leaf blister mite or grape bud mite, which is already present in WA.

The virus infects the plant systemically, meaning that all infected vine tissue can function as a source of inoculum. There is no known cure for infected vines.

To date, no GINV–infected material has been detected in Western Australia. Grape growers can be assured that DPIRD is taking proactive and precautionary steps to protect the state’s grape industry, including updating import requirements, and closely monitoring reports of suspect plant material.

Advice to WA grape growers

Although GINV has not been detected in WA, growers can take steps now to protect their vineyards.

1. Only buy from accredited sources

Visual symptoms are not sufficient for confirmation, as they resemble other viruses or non-viral problems.

■ Buy virus tested seed, seedlings, and graft material from reputable suppliers.

■ In WA, rootstock and vine suppliers can request testing for GINV by the DPIRD Diagnostic and Laboratory Services (DDLS) — charges may apply.

2. Control potential vectors

Check for blisters/galls protruding from the upper leaf surface indicating infestations of erineum mite (Colomerus vitis). This mite is a significant pest found in Western

Australian vineyards, known to contribute to yield decline and restricted spring growth.

3. Monitor and report

■ Familiarise yourself with signs of GINV — especially berry necrosis and leaf mottling.

■ Regularly inspect crops for unusual symptoms.

■ Investigate all potential causes of poor shoot growth across the vineyard — it can also be caused by abiotic factors, mites, and other diseases Fact-sheet-restricted-spring-growth.

If you see unusual symptoms — or even suspect the presence of GINV — report it. Reports can be made via the MyPestGuide® Reporter app or online at mypestguide.dpird.wa.gov.au, Early reporting helps protect your business and grape growing industries.

MyPestGuide® Reporter

via app or online mypestguide.dpird.wa.gov.au

Pest and Disease Information Service

08 9368 3080 padis@dpird.wa.gov.au