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Management plan for Grapevine leafroll disease and Shiraz disease on the horizon for growers

A newly completed project sets out a plan for Australian grapegrowers to better manage Grapevine leafroll disease (GLD) and Shiraz disease in vineyards.

The project, funded by Wine Australia, did not embark on any new research. Instead, the focus was on evaluating current knowledge from within Australia and overseas of how to respond to the target viruses.

The best practice guide, ‘Grapevine leafroll disease and Shiraz disease: interim recommendations for management in Australian vineyards’ – authored by international expert Dr Vaughn Bell from the New Zealand Institute for Plant and Food Research – contains the latest research information. It details a multi-tactic, whole-of-industry response, focussed on preventative measures and early intervention to reduce and contain virus spread.

Key recommendations from the guide highlight the importance of: • early detection of virus infection in grapevines • identifying and removing diseased grapevines, and • monitoring and managing the insects responsible for the spread of the viruses within and between vineyards.

The guide also reinforces the importance of sourcing vines certified as virus-free when planting.

New Zealand Winegrowers, the national industry body in NZ, began tackling Grapevine leafroll disease (GLD) in the early 2000s and Dr Bell said that in the years following, growers gained considerable experience in implementing an in-vineyard response to these economically important viruses.

The recommendations in the guide are based on the NZ experience and current Australian knowledge. There are sections on visual symptom identification, effective roguing, the importance of vectors and their management and best practice testing procedures, supported by decision support trees.

“Many of the ideas and responses described in the Wine Australia project report have been tried and tested in New Zealand, and while differences in grape growing between countries are acknowledged, many virus management principles are similar and can be applied in Australian vineyards with confidence,” Dr Bell said.

Dr Bell said some of the concepts proposed in the Australian guide will be new to many growers, so implementing all aspects of the proposed management plan may be challenging. However, he stressed the importance of initial action.

“A good starting point is to at least begin assessing virus incidence across the vineyard. A good understanding of virus incidence in different single variety blocks is the basis for other decisions.” More detail on the Guide can be found on the Wine Australia website. ¢

Research captures the impacts of vineyard floor management

The more plant species and plant cover you have on your entire vineyard floor, the higher soil organic carbon and water infiltration rates you will see as a result, preliminary findings of a new study suggest.

The research project compared 25 vineyard sites in McLaren Vale and the Barossa which have been using different vineyard floor management practices for at least the past three seasons.

Soil measurements and plant diversity were then evaluated seasonally at each vineyard during one growing season.

“This approach aimed to uncover any trends associated with how particular practices across a viticultural landscape, such as herbicide-use, cultivation, grazing, and cover crops, influenced dynamics related to soil health and biodiversity,” said Merek Kesser, a viticultural PhD candidate at the University of Adelaide, and a Wine Australia PhD scholarship recipient.

RESEARCHER IN FOCUS Merek Kesser

Merek said the Barossa and McLaren Vale regions provided excellent opportunities to carry out this research as they are both premium wineproducing areas with a high density of land used by vineyards.

“It is unusual to use entire vineyard sites as replicates in a scientific study, yet we did just this as we thought it was important to capture what is happening on a larger scale in the sector. Studying at the landscape level allowed for the assessment of how management practices can have different outcomes depending on the many site-driven factors that come into effect, including for example, soil type.”

While results are still in the preliminary stage, Merek said it was apparent that practices which increased the number of plant species and the duration of complete plant coverage (in both the mid- and undervine areas) resulted in soils with faster water infiltration rates and higher contents of organic carbon.

“In Australian conditions where access to ample irrigation water is a major concern, these are very insightful findings, which if taken into consideration could have a great influence on the environmental health of viticultural landscapes.”

In Australian conditions where access to ample irrigation water is a major concern, these are very insightful findings, which … could have a great influence on the environmental health of viticultural landscapes

Merek said integrating a living mulch of diverse or native plant species into the under-vine area would ultimately benefit the functionality of the soil and improve long-term vineyard resilience.

She said the research could help growers in selecting floor management strategies going forward, “which can maximise the long-term resilience and sustainability of their vineyard based on their specific production goals and site constraints.”

“With increasing pressures from external factors such as changing climate, more frequent droughts, and shortages of farm inputs including fertilisers, we are hopeful that simple vineyard floor management strategies such as keeping complete living plant coverage year-round on vineyard floors could provide holistic agroecosystem benefits.” ¢

Standard for grapevine propagation material a step closer

Phase 1 of a project to deliver national certified standards for grapevine propagation material has been completed.

Grapevine propagation standards will provide assurance to growers, vineyard managers and winemakers that any new grapevine planting material has been produced in a way that demonstrates best practice in virus and grapevine trunk disease management, traceability and identity verification.

Nick Dry from Foundation Viticulture, who has been working in consultation with the wine and propagation sector on the organisational and regulatory framework for the Standard as well as an implementation model, said it was an important step forward for the Australian grape and wine sector.

“It is well recognised that the impacts of propagation and planting material related problems – including virus, trunk disease, off-types and general poor performance – are a significant costburden to vineyard end-users,” said Nick.

“The fact that cuttings and planting material also have minimal to zero external or physical attributes indicating that they carry pathogen, genetic or performance risks also creates ‘quality uncertainty’ for both customers and suppliers.”

Nick said the development of robust and well-managed grapevine propagation certification programs that are built on defendable best science would provide pathogen, genetic and performance assurance to suppliers and customers.

“The recent identification of grapevine red blotch virus has further highlighted the importance of investing in the development of certified standards as a means to protect commercial vineyard assets,” he said.

Phase 1 of the project set the over-arching quality assurance objective(s) and the organisational and regulatory framework for a standard. An implementation model was also developed, which covers development of the written standards, delivering and adopting the standards and a review phase. Phase 2a commenced in October and will address the immediate priorities for the sector.

These include the development of a source block asset register, quantifying the value proposition for certified planting material, continuing to develop detail around governance and funding as well as developing and implementing a communication strategy.

“Research projects will also be required to underpin the Standard. For example, a scientific basis will be developed for managing virus and trunk disease in the propagation supply chain. ”

“Ultimately the end-goal is to have scientifically-validated standards in place by 2026 that will cover the whole of the propagation supply chain,” said Nick.

“To achieve this we will continue to work in concert with propagation stakeholders including the Vine Industry Nursery Association and the State and regional vine improvement groups.” ¢

Capturing agtech experiences of Australian producers

Wine Australia has developed a new video series Reading between the vines that aims to capture how Australian grape growers and winemakers are using the latest agtech in vineyards and wineries.

In the series, grapegrowers and winemakers discuss their experiences using agtech, the types of technologies they’re deploying and how these are driving better outcomes.

Producers and technologies featured in the series so far include: • Brooke Howell from Yalumba who has been using a mobile app from

Onside to improve operational safety and security across their Barossa vineyards • Nigel Blieschke from Torbreck who has been using Swan System’s water and nutrient management software to improve vine consistency at

Torbreck’s Barossa vineyards • Hans Loder from Penley Estate who has been using Athena

Irrigation’s system to gain a greater understanding of grapevine water requirements • Another interview with Hans Loder about what he has found through his

Nuffield Scholarship investigating maximising the benefits from agtech for viticulture, and • Tony Hoare from Beach Road Wines in McLaren Vale who has been using the Arable mark 2 weather station for hyper-localised weather insights at his vineyards Upcoming episodes will include: • James Meyer from Hill River Clare

Estate in Clare Valley who has been working with Airborne Logic to produce precise digital maps for detailed vineyard analysis • Rob Sutherland and Emma Taylor from Debortoli Wines Yarra Valley vineyards who have been using

Bitwise Agronomy’s Greenview system to support site management with its vine-based image technology. • Ben Thomson from Bests Wines in

Grampians who has been using

Smart Apply to reduce vineyard spray application through its active sensor technology.

View the series at Wine Australia’s Agtech Hub – wineaustralia.com/ growing-making/agtech-hub or subscribe to Wine Australia on YouTube. ¢

Future Leaders 2023 – applications opening in January

Applications will open in January for the next vintage of the grape and wine sector’s leadership program Future Leaders.

Inspiring individuals with inquisitive minds from across the grape and wine sector value chain are encouraged to apply.

The five-month program tailored for the grape and wine sector equips professionals with new skills to enhance their contribution to the community. It supports a new generation of grape and wine sector leaders to develop skills, sharpen decision-making abilities, build networks, and form a nucleus of knowledge and enthusiasm to take the sector forward, in good times and bad.

More than 100 leaders in the Australian grape and wine community have completed the program and are all parts of the grape and wine value chain – from viticulture and winemaking to marketing, sales and export, ecommerce and market development, managers, regional associations, research, and production.

Future Leaders 2022 graduate Steve Faulkner, Senior Viticulturist at Oakridge Wines said, “The learning and real-life application of that learning has been invaluable. I recommend applying for Future Leaders, just do it. Personal development and leadership skills for life lie ahead if you are successful.”

Visit winefutureleaders.com for more information and to apply. ¢

Wine Australia

Industry House, cnr Botanic & Hackney Roads Adelaide SA 5000 PO Box 2733 Kent Town SA 5071 08 8228 2000 research@wineaustralia.com wineaustralia.com • t l