The Wine Blokes

By Sarah D

Big news in the Australian wine industry is the past few weeks has been the recent outbreak of Phylloxera found in the Macedon Ranges of Victoria. Sarah Dalkin provides some insight into this serious pest to the Australian wine industry.

Grape phylloxera (Daktulosphaira vitifoliae, family), commonly called Phylloxera and pronounced fil-ox-era is a pest of commercial grapevines worldwide, originally native to eastern North America. These tiny insects are related to aphids and feed on the roots of grapevines. In Vitis vinifera, the resulting deformations (”nodosities” and “tuberosities”) and secondary fungal infections can strangle roots, gradually cutting off the flow of nutrients and water to the vine. Vines gradually become weaker and weaker with vineyards eventually becoming unproductive.

The spread of this pest can and does have huge economic impacts for the wine industry and many associated industries through lost production and the economic impacts of adhering to quarantine protocols. Phylloxera wiped out millions of acres of grapevines across Europe in the mid-1800s and arrived in Victoria in 1877. Phylloxera has been found in some regions within NSW and Victoria but is currently not present in South Australia, Western Australia or Tasmania. Nationally agreed protocols managed by the Phylloxera Board of South Australia regulate the movement of filtered juice, whole grapes, crushed grapes (must) and used agricultural machinery and bins from phylloxera-affected areas to wineries in other parts of Victoria and interstate. Adhering to these protocols adds significantly to wineries production costs as they may need to install heat treatment sheds and facilities for hot washing bins and winery equipment. Adherence to these protocols is however critical in the control of this pest.The biggest line of defence against Phylloxera is the use of rootstocks that are resistant to the pest and will therefore not show the decline seen on Phylloxera infected grape vines planted on own roots. This can cost growers more in vineyard establishment due to increased planting material costs but this certainly acts as good insurance should the pest spread further within Australia. There is a well-established process to respond to detections of Phylloxera, under the National Phylloxera Management Protocol. A control or quarantine zone is formally established and surveys are conducted to determine if the pest is also present in any surrounding vineyards, or in other vineyards with links to the affected property.

The most recent previous detection of Phylloxera was in the Yarra Valley in December 2006; other detections have been made at a number of sites in north-east Victoria and there are currently 63 vineyards in Victoria which are registered as being infected with Phylloxera.

Every effort is made by wine industry personnel to ensure that the pest is contained, however this becomes increasingly difficult with winemakers today often visiting many different vineyards and regions throughout vintage. Vineyard machinery is also often used in many different regions, which can increase the risk of spread of this pest.

So along with drought, bushfires and frosts another challenge that grape growers and winemakers have to contend with is an aphid! Life on the land was never meant to be easy!!