National project launched to tackle devastating walnut blight

Preventing substantial yield losses and securing the future of the walnut industry will be the focus of a new project announced by Hort Innovation.  

Led by Applied Horticultural Research Pty Ltd, the five-year initiative aims to develop sustainable and effective management strategies to address walnut blight - a destructive disease that causes significant yield loss for walnut growers. The project is also expected to deliver solutions that extend beyond the walnut industry, delivering potential benefits for Australia’s vegetable sector. 

Current chemical-based control methods for the disease have been found to be increasingly ineffective and costly. This new project will focus on finding alternative biological and chemical controls and examine the environmental factors influencing disease spread. The goal is to give growers practical solutions to control walnut blight, reduce environmental impact, and enhance the long-term resilience of the industry. 

Brett Fifield, CEO at Hort Innovation explained what this means for the industry: 
“Walnut blight is a serious threat to productivity and profitability. This project is about equipping growers with smarter, more sustainable tools to manage the disease and future-proof the industry.”  

“What makes this project particularly exciting is its potential to benefit Australia’s vegetable industry as well. We know walnut blight and black rot in vegetables are caused by similar bacterial pathogens, but unlike vegetables - where the disease can wipe out crops in just weeks - walnut blight persists across seasons. This, along with the longer crop cycle of walnuts, gives researchers a greater window to observe and test solutions. Our hope is that by finding solutions for walnut blight, we’ll unlock tools to help manage black rot in brassica vegetables like cabbage, broccoli and cauliflower too.”  

Gordon Rogers, Managing Director of Applied Horticultural Research, added: 
“This project is a game-changer for affected growers. By combining cutting-edge science with practical field trials, we’re aiming to deliver solutions that are not only effective but also sustainable and accessible for growers across Australia. Our team includes the major walnut producers in Australia, and also experts in walnut diseases in Australia and internationally. We hope to find solutions quickly by applying the best expertise available.” 

By collaborating with industry and research partners, Hort Innovation aims to deliver outcomes that benefit both walnut and vegetable growers, as well as industry bodies, and regulators, supporting improved disease management and a more resilient sector overall.  

This project is funded through Hort Innovation Frontiers with co-investment from Applied Horticultural Research (AHR) and contributions from the Australian Government. 

While walnuts are not a Hort Innovation levy-paying industry, this project is supported through the Hort Innovation Frontiers program, which enables work on cross-sectoral issues that benefit levy-paying horticulture industries.