There is an almost invisible wall around the vineyards and wine regions of Australia. It comes in the form of agencies and government departments whose job it is to protect our valuable vineyard resources for generations to come. Since phylloxera ravaged the vineyards of the world in the late 19th and early 20th centuries, there have been controls put in place to protect the Australian wine industry.
However, recent years have seen an increasing risk posed by pests and diseases that could potentially wreak havoc in the vineyards. The rise in international trade and tourism, agricultural expansion and climate change have all played a part in making the challenge of biosecurity more pressing than ever before. With a cost of replanting at $600,000 or more per hectare, not to mention the lost years of production, there is obviously plenty at stake.
In California, Pierce’s disease alone costs the wine industry more than $100 million a year – not only in wine production, but also research and compliance costs. The Covid-19 pandemic has also extended biosecurity to the labour force working in wineries and vineyards.
While it is more than a century since phylloxera was at its peak, it remains the key biological challenge for the wine industry.
Particularly prevalent in some New South Wales and Victorian wine regions, an outbreak was detected in the Yarra Valley in 2006, which has now spread to around 38 vineyards. Potentially the whole of the Yarra Valley could in the future be declared a ‘Phylloxera Infested Zone’.
To stop the spread, every state has its own legislation that is regularly updated depending on risks. South Australia, one of the three phylloxera-free states, updated laws again in 2020, which made it illegal for any grapes or marc grown in a ‘Phylloxera Risk Zone’ to enter South Australia. In addition, second-hand vineyard materials, such as trellis posts and netting, are also prohibited, as is the use of steam for sterilising used equipment and machinery imported into Australia.
While phylloxera obviously presents significant risks within Australia and there are other current local challenges such as leafroll virus and eutypa dieback, much of the effort to protect the Australian wine industry is in mitigating against the importing of exotic pests and disease. This is against a backdrop where biosecurity is becoming more challenging and requires not only constant vigilance against new threats but also the development of new protocols to counter those threats.
An example of this is Grapevine Pinot Gris Virus, first discovered in Italy in 2012, which is now found throughout the world, including in Australia. As yet, little is known about the full impacts this can have on grapevine growth and wine quality.
One key element in the protection of Australia’s vineyards is ensuring any imported grapevine material is not contaminated. This process has been known to take more than a decade, from importing cuttings through to planting a vineyard with new clones or varieties. The process for dormant cuttings involves a visual inspection, fumigation, hot water treatment then surface sterilisation – and that is just to start.
Cuttings are then grown in a secure facility for a minimum period of 16 months, during which time they are screened and tested for pathogens. Numerous cuttings are required as many will not survive the process. With varietal innovation an important component of the future of the Australian wine trade, this fundamental but necessary step adds a significant amount of time when testing new varieties.
But protecting vineyards doesn’t only focus on grapevine materials. Pests can be transported into Australia via everyday cargo pallets so the biosecurity wall also extends into Customs and the Australian Border Force, ensuring none of the pests dangerous to vines and wine quality – such as the brown marmorated stink bug – enters the country. These stink bugs are of particular concern as they not only damage fruit but can taint wines if in high enough numbers.
As an isolated country, Australia is in an enviable position when it comes to biosecurity. This control over what enters our borders has not only helped the country to retain some of the oldest vines in the world but also provided a level of protection against many pests that are endemic in other wine regions around the world. Hopefully this will continue to be the case for many years to come.