This project will develop practical strategies for grapevine trunk disease management with consideration for the diverse climates of Australian viticulture by:
- developing climate specific recommendations to minimise infection,
- optimising wound protection and remedial surgery techniques,
- assessing susceptibility of clones and rootstocks, and
- investigating infection thresholds for grapevine propagation material
Eutypa dieback and botryosphaeria dieback are major grapevine trunk diseases that threaten the sustainability of Australian vineyards. Causal fungi infect pruning wounds and colonise wood, causing dieback and vine death.
Methods for quantifying pathogen DNA on spore trap tape have been developed, but a novel loop-mediated isothermal amplification (LAMP) assay has potential to detect DNA on spore tape and in propagation material in the field.
Pruning wound fungicides are being registered and can be applied with sprayers. However, the ability of fungicide adjuvants to maximise wound coverage and critical timing of biocontrol application are unknown.
Remedial surgery is the only effective method for managing Eutypa dieback-affected vines and current research is providing short-term results for managing botryosphaeria dieback-affected vines, but data on medium-term effectiveness are lacking.
There is evidence of cultivar tolerance to trunk disease but observations that clones and rootstocks vary in susceptibility may offer additional means of disease management.
With the development of highly sensitive diagnostic tools and concern about disease spread in nurseries, it is important to establish infection thresholds in propagation material that lead to subsequent disease symptoms.
Research will be focused to address these issues and will:
- Continue surveillance of inoculum dispersal using qPCR methods and develop a LAMP assay to detect spores in the field
- Determine pruning wound susceptibility in a warm-wet climate
- Maximise wound coverage of fungicide and evaluate efficacy of natural alternatives for wound protection
- Optimise remedial surgery techniques through field trials in SA and NSW
- Assess the susceptibility of clones and rootstocks
- Investigate infection thresholds in propagation material
This research will develop and publicise new and improved management strategies to prevent and control grapevine trunk diseases. It will also contribute to improving vineyard performance by identifying clones and rootstocks with tolerance to trunk disease and provide new knowledge on the role of vine propagation in disease spread.