The findings from recent research into phylloxera by Agriculture Victoria researchers Catherine Clarke and Jessi Henneken have enhanced our understanding and control of phylloxera.
The importance of using rootstocks based on phylloxera genotypes
With no treatments available to eliminate phylloxera from vineyards, phylloxera-resistant rootstocks remain the primary control method, though these grafted vines are significantly more expensive at three to five times the cost of own-rooted plants.
Rootstock resistance varies by phylloxera genotype, so selecting the appropriate rootstock for specific local strains is essential, particularly given there has been 166 phylloxera strains identified in Australia.
Recent research has shown that matching rootstock resistance to local phylloxera genotypes is especially important in regions with virulent strains like G38 in north-east Victoria. Certain rootstocks, such as M5512 and M5489, exhibit tolerance to specific genotypes, enabling growers to manage phylloxera impacts more effectively.
Wine Australia’s Rootstock Selector Tool, originally developed by Yalumba Nursery with support from CSIRO’s Dr Rob Walker, Peter Clingeleffer, Vinehealth Australia, consultants and technical specialists provides valuable guidance for these decisions. It can be accessed at www.grapevinerootstock.com.
Advances in detection and surveillance
Effective phylloxera management relies on early detection. Traditional surveillance, which involves visually inspecting vine roots, is time-intensive and may miss infestations.
Recent research has shown that LAMP (loop-mediated isothermal amplification) testing on root samples offers a highly sensitive alternative.
This DNA-based test can detect phylloxera even when population numbers are low, for example, in winter outside of peak phylloxera activity. When combined with visual inspections by experienced surveyors, the test captured over 90% of positive detections. Conducting these surveys in autumn, when phylloxera is most active on roots, further enhances detection accuracy and allows more timely intervention.
New findings on machinery disinfestation
Phylloxera spreads through soil, plant material and contaminated equipment, often hitching rides on footwear, vehicles and vineyard machinery. Recent research highlighted that machinery disinfestation is only effective when equipment is thoroughly cleaned of soil and plant matter.
Phylloxera can survive if shielded by debris, so a revised protocol now requires cleaning all equipment before applying dry heat treatment at 50°C for two hours.
This updated procedure is essential for machinery that may have been exposed to infested soil or plant material.
State-specific biosecurity regulations limit spread
Strict movement regulations under the Biosecurity Act 2015 help limit phylloxera spread. Growers should consult state biosecurity agencies for up-to-date movement restrictions, treatment requirements and certification standards.
In summary
The recent findings underscore the need for collective action to prevent phylloxera spread. Key strategies include:
- conducting regular surveillance and employing advanced methods like LAMP testing
- choosing phylloxera-resistant rootstocks appropriate to local genotypes
- adhering to stringent biosecurity protocols, particularly for machinery and plant materials.
By remaining proactive and informed, the Australian wine industry can continue to protect its vineyards, supporting the long-term quality and sustainability of Australian wine production.
Resources
Vinehealth Australia, 2024, Grape phylloxera, viewed 6 November 2024, www.vinehealth.com.au/pests/pests-and-diseases/phylloxera
Agriculture Victoria, 2024, Best practice viticulture biosecurity for phylloxera, viewed 6 November 2024, www.agriculture.vic.gov.au/biosecurity/protecting-victoria/victorian-viticulturebiosecurity/best-practice-viticulture-biosecurity
Henneken, J, Clarke, C, Valenzuela-Gonzalez, I, Kwong, R, Blacket, M & Cunningham, P, 2024, Wine Australia Final Report: DJP 2001 Integrated Management of Grapevine Phylloxera Phase II.
Phylloxera detection: grower guidelines, 2021, www.dpi.nsw.gov.au/agriculture/horticulture/grapes/biosecurity/phylloxera-detection-grower-guidelines
IMAGE: Phylloxera in a dissected leaf gall. Photo courtesy: James Buxton’, Agriculture Victoria Research