New mildew and drought-resistant grapevines at Wynns Coonawarra Estate could help future-proof Australia’s wine industry against climate change and disease.

Wynns Coonawarra have partnered with Australia’s national science agency, the Commonwealth Scientific and Industrial Research Organisation (CSIRO), to help safeguard the future of some of the oldest and most historic vines in the Coonawarra wine region.

The new grapevines blend genetics from TWE’s heritage vines in Coonawarra and Penfolds in the Barossa Valley, which have an enhanced climate resilience, with mildew-resistant traits developed through years of selective breeding by CSIRO, with funding from Wine Australia.

Powdery and downy mildew diseases cost the Australian wine sector an estimated $160 million in management expenses and production losses annually to Australia’s $45 billion wine industry.

The first 204 individual progeny seedlings were selected from crosses between Cabernet Sauvignon vines from original vines across the 2 renowned winemaking regions and CSIRO’s second-generation mildew-resistant breeding lines. The vines were planted in South Australia in late 2024. The best-performing vines, together with small-batch winemaking trials, will be used to select new varieties.

CSIRO research scientist and project lead, Dr Paul Boss, said that breeding mildew resistance into “elite” vines provides the future grapevines with a genetic advantage against these disease-causing pathogens.

“Using traditional breeding methods, we introduced two distinct genes to the Wynns heritage vines, which give resistance to downy mildew and powdery mildew,” Dr Boss said.

“These are from CSIRO-developed breeding lines that confer robust disease resistance and other quality traits onto their progeny.

“Having resistance genes for both powdery and downy mildew makes these plants more robust as it is unlikely the pathogens can break both sources of resistance with a single mutation.”

Through many decades of exposure to climate extremes of hot, cold, wet and dry, the heritage vines from the Wynns and Penfolds vineyards have developed a natural resilience to drought, making them prime candidates for further development to enhance their tolerance to climate extremes.

Chief supply and sustainability officer at Treasury Wine Estates, Kerrin Petty, said that managing grapevine disease pressures sustainably, whilst adapting to the increasingly variable growing conditions brought on by climate change are significant challenges facing the wine industry across the globe.

“In partnering with CSIRO for this important project, we’re combining the genetics of heritage Australian vines from our renowned Wynns Coonawarra Estate and Penfolds brands with scientific research and innovation,” said Petty.

“Creating mildew resistant vines that are also able to withstand climatic variation means we’re setting up our vineyards to continue producing world-famous wine for generations to come.”

Wynns Senior Winemaker Sue Hodder said, “Climate change is already impacting how our grapes are grown, and we need to harness the latest in scientific research so we’re ready for the next century of producing outstanding wine for this important label.”

Wynns Viticulturalist Ben Harris said, “For decades, we’ve been taking cuttings from the best vines in our famous Johnson’s Block in Coonawarra and using traditional breeding processes to create the next generation of superior vines. This initiative blends heritage vineyards and the art of traditional winemaking, with the latest science.”

The resulting superior cultivars are expected to require fewer inputs, such as the application of fungicide sprays, which will likely lead to additional sustainability benefits including lower carbon emissions from less frequent use of diesel-powered tractors in vineyards.

The long-term project shows how scientific innovation can be used to bolster adaptation to a changing climate and manage disease pressure, providing knowledge that benefits the wider Australian wine sector to become more sustainable into the future.

The latest collaboration with CSIRO complements the broader approach to sustainability at Wynns, encompassing viticultural and winery practices which has led to certification by Sustainable Winegrowing Australia, preservation of soil health, minimal fungicide use, the switch to renewable electricity in the winery, and a 230kW solar system on site.

The mildew-resistant grapevine breeding lines used in this project were partly funded by Australia’s grape growers and winemakers through their investment body Wine Australia with matching funding from the Australian Federal Government.