Mildew-resistant grapevine varieties

Reducing disease pressure through improved planting material

Powdery mildew and downy mildew are two economically important diseases of grapevines. Mildew-resistant varieties are being bred to give growers another way to manage these diseases while reducing reliance on fungicides.

For growers and viticulturists planning new vineyard developments, redevelopment or future planting material, these varieties could provide another option for building disease resilience into the vineyard from the outset.

Why mildew resistance matters

Mildew-resistant varieties have the potential to significantly reduce the need for fungicide applications. For a vineyard business, this could mean:

• less chemical use in the vineyard
• lower production costs associated with disease management
• reduced risk of crop loss from powdery and downy mildew
• lower vineyard emissions, and
• more sustainable vineyard management.

Developing and evaluating improved planting material also forms part of Wine Australia’s work to help growers manage pests and diseases more sustainably and increase the range of varieties, clones and rootstocks available to the sector.

What varieties are being developed?

The grapevine breeding program with CSIRO began in the 1990s, combining conventional crossing with marker-assisted selection.

The first generation of mildew-resistant winegrape cultivars, known as Gen 1, has one gene for powdery mildew resistance and one for downy mildew resistance. The varieties are being evaluated by industry partners under agreements with CSIRO and are equivalent to the ‘PIWI’ varieties grown in Europe.

Several Gen 1 varieties have demonstrated commercial potential through industry trials and have produced award-winning wines.

Read about disease-resistant varieties and industry trials

The next generation

CSIRO has also bred second-generation, or Gen 2, vines with two genes each for powdery and downy mildew resistance.

Wine Australia is working with NSW DPIRD to evaluate more than 500 mildew-resistant selections at two field sites. The aim is to select the 20 best-performing red and white selections for replicated evaluation, with the best lines potentially progressing towards commercial release as ‘no spray’ vines.

Building resistance into established varieties

In 2022, Treasury Wine Estates and CSIRO entered a long-term partnership to breed vines that combine powdery and downy mildew resistance with heritage Cabernet Sauvignon material.

April 2025 CSIRO media release

Wine Australia and CSIRO’s grapevine breeding program and explore related projects

What can growers do now?

If you are considering future vineyard planting or redevelopment:

• Follow the evaluation work. Many of these selections are still being evaluated, so keep up to date with trial results and commercial availability.
• Consider disease resistance when planning future plantings. Alongside other characteristics important to your site and business, disease resistance can be part of your assessment of future planting material.
• Look beyond disease resistance alone. Industry evaluation is also important for identifying varieties with the performance and wine quality needed for commercial use.
• Keep current vineyard disease-management practices in place. The varieties described here are under evaluation and should not be interpreted as a replacement for existing disease-management practices in established vineyards.

Wine Australia’s broader planting-material investment includes developing and evaluating varieties, clones and rootstocks suited to sustainable vineyard practices.