During the mid-1800s, European vineyards were ravaged by a mysterious pestilence and the industry was in crisis. Previously healthy vines were beset by diminished vigour, reduced yields and finally, death. By the end of the 19th century, 70% of vineyards were decimated and it seemed that wine production might come to an end. Eventually the cause was identified, originally termed ‘Phylloxera vastatrix’, literally, ‘phylloxera the destroyer’.
The industry was eventually spared by the introduction of American rootstocks, which had evolved in the presence of phylloxera and were naturally resistant. The pest, now known as Daktulosphaira vitifoliae, is present in NSW and Victoria, including north-east Victoria and Geelong where it has been endemic for decades. However, its arrival in the Yarra Valley in 2006 was a shock to the community, inflicting a crushing blow on producers who have spent 15 years coming to terms with this new reality.
Barely visible to the naked eye, adult phylloxera fly from vine to vine, leaving larvae that crawl into the soil and attach themselves to the roots. The organisms feed on sap, ring-barking the vine underground. Rigorous hygiene measures can limit spread but there is no pesticide that can eradicate phylloxera. Once infested, vineyards must be removed and replanted with vines grafted onto phylloxera-tolerant rootstocks.
This was devastating news for the Yarra, where most vineyards were planted with ungrafted stock. Initially, growers minimised the impact with biosecurity measures, however, its spread has continued. Since 2006, the boundaries of the Phylloxera Infested Zone have been redrawn seven times and now include the entire region.
Growers are confronted with the reality of forced replanting, a demoralising undertaking for those with established and sometimes historic vineyards. It is an expensive, laborious and time-consuming endeavour not feasible for all producers. Vinehealth Australia describes it as a billion-dollar problem. Even for those in a position to replant, there are delays in resuming wine production during the 3-4 years it takes to establish new vineyards.
Hoddles Creek winemaker, Franco d’Anna has noted other impacts. “We’re also seeing a production decline, which has been exacerbated by several small vintages in the last five years.” Reduced production can cause fruit prices to rise, increasing competition among wineries.
Nevertheless, there is a sense of optimism among Yarra Valley producers. Many are choosing a ‘lemons-to-lemonade’ approach to phylloxera, taking the opportunity to re-evaluate prevailing practices. Coldstream Hills founder James Halliday recalls similar responses to phylloxera’s discovery in California in the late-1980s. “It was cast as a billion-dollar catastrophe. Many vineyards had to be removed because it was just rampant.” Growers set about making changes, including better selection of varieties and sites, revising vineyard orientation and improved row spacing. “All of those things were addressed and this made for improved economic production. There are a number of offsets to the original cost of infestation – it was much [less damaging] than a billion dollars.”
Natillie Johnston, winemaker at Tillie J Wines has seen benefits in the Yarra, too, “It’s been a really good opportunity to learn and grow, to rethink vineyards and what is suited to the current sort of climate and growing conditions in general.” Grafting has also presented opportunities, with the choice of rootstock as important as the variety itself; “You can select really specifically a rootstock that will suit a particular vineyard.”
Pimpernel Vineyards winemaker Damien Archibald is taking advantage of replanting to rootstock to mitigate the consequences of climate change. “We’re choosing low-vigour rootstocks that will hopefully prolong the season by a couple of weeks, so that we can get a longer ripening period. By adjusting the direction of rows, and having vines running east-west, we’re hoping to protect the vines from sunburn.”
He’s not alone in making such changes. The arrival of phylloxera has also prompted other growers to reflect on the impacts of extreme weather events and climate change.
“I think what we’re seeing is an opportunity to invest in the vineyard and replace those varieties that weren’t suitable,” says d’Anna who trialled various rootstocks before settling on Teleki 5CA at Hoddles Creek. Other producers, including Pimpernel Vineyards, are considering the addition of alternative Mediterranean varieties like sangiovese, which are suited to warmer, drier conditions.
Looking forward, Yarra Valley growers are taking these changes in their stride, and seem cautiously optimistic about the phylloxera challenge and what the positives that would flow from overcoming it could mean for the future of the region.