Independent review of Septoria tritici blotch in wheat program of investments and future RDE directions

Septoria tritici blotch (STB) is a stubble-borne foliar disease of wheat caused by the fungus Zymoseptoria tritici and is increasingly problematic across Australia's high and medium rainfall zones. In recent years, STB has expanded its reach into low-rainfall areas, driven by factors such as stubble retention, intensive wheat cropping, and the widespread cultivation of susceptible varieties. The disease thrives under cool, wet conditions, with outbreaks often triggered by frequent rainfall and extended leaf wetness. Yield losses can reach up to 50% in vulnerable crops, and fungicide resistance is escalating, making chemical control less reliable. Integrated disease management (IDM) strategies, including variety selection, paddock rotation, and stubble management, are essential to mitigate its impact. However, the limited availability of resistant varieties and the evolving virulence of STB isolates continue to challenge growers and researchers alike. 
To address these challenges, the Grains Research and Development Corporation (GRDC) has invested in a suite of targeted research programs and is now initiating a formal review of these investments.