Grapevine Pinot Gris virus

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Grapevine Pinot Gris virus (GPGV) is established in Australia and has been detected in NSW, Victoria and SA, as well as grape-growing regions worldwide.

Why GPGV matters

GPGV is important because it can spread through propagation material and may be transmitted by bud and blister mites. Overseas studies have associated GPGV with vine growth disorders, reduced productivity and a condition known as grapevine leaf mottling and deformation (GLMD). However, the impacts vary significantly between varieties, regions and vineyards.

Australian and international research has shown that:

some infected vines show symptoms
some infected vines show unusual symptoms that are difficult to link directly to GPGV
some infected vines remain symptomless

This means visual assessment alone cannot be relied on when making planting, redevelopment or vineyard management decisions.

GPGV is also frequently detected alongside other grapevine viruses, making it difficult to determine the contribution of GPGV alone to observed symptoms or production impacts.

Symptoms

Symptoms associated with GPGV infection may include:

delayed budburst
shortened internodes and stunted shoot growth
leaf mottling or mosaic patterns
leaf distortion and deformation
stunted or zig-zag shoot growth
bunch shatter
delayed ripening
increased berry acidity
reduced bunch numbers or bunch weight
reduced productivity in some vineyards.

Symptoms are often most noticeable early in the growing season and may become less obvious later in the season.

Symptoms associated with GPGV can resemble:

bud mite damage
blister mite damage
herbicide injury
nutrient disorders
cold damage.

Laboratory testing is required to confirm whether GPGV is present.

How GPGV spreads

Propagation material

The greatest risk of introducing GPGV into a vineyard comes from infected propagation material, including:

potted vines
cuttings
rootlings
budwood
grafting material.

Because infected vines can show no symptoms, testing is an important risk management tool when sourcing planting material.

Bud and blister mites

Research has demonstrated that grapevine bud and blister mites (Colomerus vitis) can transmit GPGV between vines. These mites are widespread in Australian vineyards and are considered a likely pathway for local spread.

Bud mite damage can resemble GPGV symptoms, including shortened internodes and distorted growth.

Alternative hosts

Several alternative plant hosts have been identified overseas, including Fat Hen (Chenopodium album), White Campion (Silene latifolia), some rose species, blackberries and raspberries.

The role of these species in virus spread is still being investigated, but controlling weeds and alternative hosts may help reduce risk within vineyards.

Equipment transmission

There is currently no evidence that GPGV is spread through pruning equipment, harvesting machinery or normal vineyard operations.

What this means for vineyard management

Use high-health planting material

Where possible, source high-health, virus-tested planting material from reputable accredited suppliers.

When purchasing vines or planning top-working programs, consider requesting evidence of virus testing for both scion and rootstock material.

Monitor for unusual growth patterns

Pay particular attention during spring when symptoms are most likely to be observed.

Look for:

delayed budburst
shortened internodes
distorted leaves
patchy stunting
unusual vine-to-vine variation within blocks.

Manage mite populations

Bud and blister mites are known vectors of GPGV. Monitoring and managing mite populations should form part of routine pest management.

Test, don't rely on symptoms alone

Because infected vines can appear healthy, laboratory testing is the only reliable way to confirm GPGV infection.

Testing may be appropriate when:

unusual symptoms are observed
vineyards are being assessed for redevelopment
mother blocks or source blocks are being used for propagation
vineyards are being top-worked
redevelopment is planned
planting material is being assessed before purchase.

Contact an accredited grapevine virus diagnostic laboratory for current testing options and sampling requirements.

Key takeaways

GPGV is established in Australian vineyards.
Infected vines may be symptomatic, asymptomatic or symptomless.
The virus spreads primarily through infected planting material.
Grapevine bud and blister mites can transmit GPGV between vines.
Symptoms can resemble other vineyard issues and should not be used to diagnose infection.
Laboratory testing is required to confirm the presence of GPGV.
High-health planting material, virus testing and mite management remain the most effective tools for reducing risk.