The South Australian Research and Development Institute (SARDI) has issued a call for samples of powdery and downy mildew fungal infections, with the aim of monitoring and managing fungicide resistance.
This initiative is crucial for maintaining the effectiveness of fungicides and ensuring the long-term health and productivity of vineyards.
The challenge of fungicide resistance
Fungal diseases such as powdery mildew, downy mildew, and botrytis bunch rot are persistent threats to Australian vineyards. Over time, these pathogens can develop resistance to commonly used fungicides, rendering treatments less effective and leading to increased disease outbreaks and economic losses.
SARDI and other research organisations have completed a Wine Australia project on ‘Improving the understanding of fungicide resistance in Australian viticulture’. Since mid-2023 this is now within the CRC SAAFE research program ‘Fungicide Resistance in Grapevine’ with industry project partners.
Historically, fungal disease analysis has been limited to samples where fungicide resistance is suspected due to product failure. This season, SARDI research will focus on collecting as many samples as possible from Australian grape growing regions to gauge the levels of resistance in the natural populations.
Testing for fungicide resistance is not a simple process for growers to undertake in their own vineyards. Samples will need to be sent to SARDI to measure the fungal disease susceptibility to various fungicide activity groups by looking for specific mutant genes.
Importance of sample collection
Collecting samples from various regions is essential for several reasons:
- Tracking resistance patterns: Understanding how resistance develops and spreads helps in formulating effective management strategies.
- Guiding fungicide use: Data from samples can inform the selection and rotation of fungicides to delay resistance.
- Ensuring spray effectiveness: by knowing the resistance status of your own fungal diseases, you can avoid fungicides with known resistance avoiding wasting money on chemicals and costs of treatment. You will similarly find out what fungicides remain effective
How vineyard owners can help
Vineyard owners and managers are encouraged to participate by submitting samples of vines showing signs of only powdery and downy mildew fungal infection. Here’s how you can contribute.
- Collect samples as per the guidelines.
- Note that each fungal disease has different methods of sampling, collection, packing with documents, shipping and storage.
- Avoid sampling and sending samples late in the week as they may sit in postal services over the weekend and degrade.
Sample testing is free. Growers will need to collect, label and send samples along with at least 5 years of spray history, if available. All results are confidential.
For more information on how to participate and submit samples, please contact Ismail A Ismail at SARDI via email at ismail.ismail@sa.gov.au.