New rapid test to help onion growers outsmart fungicide resistance

Australian onion growers will soon be armed with the tools to stay ahead of damaging leaf diseases and protect their crops from costly losses.  

The new project, funded by Hort Innovation and delivered by Metagen, will enable onion growers to quickly identify the major diseases threatening their crops -  Stemphylium vesicarium (Stemphylium leaf blight, SLB), Alternaria porri (Purple Blotch, PB), and Peronospora destructor (Downy Mildew, DM) -  using rapid, on-farm diagnostic tests. 

By harnessing the latest genome sequencing techniques, the research team will monitor how pathogens evolve and track the emergence of fungicide resistance. Both laboratory and field trials will pinpoint which fungicides remain effective, ensuring growers can make fast, informed decisions to safeguard their yields. 

Brett Fifield, CEO at Hort Innovation, said: “Onion growers face increasing pressure from leaf diseases that threaten both yield and profitability. This project puts rapid, accurate diagnostic tools directly into growers’ hands, empowering them to make faster, better-informed decisions about disease control and fungicide use.” 

“By providing up-to-date information on fungicide resistance, we’re helping growers ensure best practice when using sprays, slowing the spread of resistance, and protecting their crops more sustainably and cost-effectively. Ultimately, this means stronger, more resilient onion businesses and better outcomes for the entire industry.” 

The project, led by Dr Ben Evert, will develop rapid tests to distinguish between the most damaging onion diseases, and will generate a national dataset on pathogen diversity and resistance, inform integrated crop management strategies, and provide extension materials for growers and diagnostic labs.  

Dr Evert said: “Fast, accurate disease identification is a game-changer for onion growers. By combining new molecular tests with real-world resistance screening, we’re giving the industry the knowledge it needs to respond quickly and stay ahead of evolving threats. Our goal is to make these tools practical and accessible for every grower. Not only will this research provide immediate impact for the growers, but the molecular test methods, genome sequencing data and fungicide resistance assays will be published and can then be accessed by other scientists all over the world.” 

This project (VN24003) is funded by Hort Innovation, using the onion research and development levy and contributions from the Australian Government.