The financial impact of phylloxera in the Yarra Valley could be around $1 billion, based on replanting nearly the whole region to rootstock and accounting for losses due to production lag. This figure would rise further when other factors such as loss of brand continuity, business value and compliance costs are taken into account.

The data was shared by Rob Sutherland, viticulturist at De Bortoli Wines in the Yarra Valley, who was speaking at a ‘Taking Tech to Regions’ workshop in McLaren Vale, held just after the Australian Wine Industry Technical Conference.

Rob said other impacts of phylloxera on Yarra Valley growers and winemakers include:

  • Difficulty in sourcing grapes due to movement restrictions
  • Short supply of rootstocks for replanting and lack of information about which rootstocks are best suited to Yarra varieties and soils; and
  • Compliance with biosecurity, in particular educating labour hire companies, contractors and consumers.

Phylloxera was first detected in the Yarra Valley in December 2006, following a severe frost in late October when a patch of vines was slow to recover.

“Phylloxera is likely to have been in this vineyard and possibly others for numerous years before detection,” Rob said.

It wasn’t until 2008 that neighbouring vineyards detected and reported phylloxera. Detections were reported in low numbers each year until 2016, when 13 new vineyards reported the presence of phylloxera.

By the end of 2017, 38 vineyards in the Yarra Valley were confirmed to be living with phylloxera. The Phylloxera Infested Zone (PIZ) boundary has been redrawn seven times since and will be redrawn again this year after three more detections were announced.

Rob said, in the future, the entire Yarra Valley GI region might be declared a PIZ.

“It’s clear that in spite of significant efforts to contain phylloxera in the Yarra Valley it is not working,” Rob said. “Phylloxera is ahead of any zone or line on a map.”

Vinehealth Australia is working with Wine Yarra Valley to plan a Phylloxera Immersion Tour to the Yarra Valley in December 2019. Look out for further details in next month’s e-news where we’ll tell you what we’re planning and how you can register your interest.