Controlling Ramularia leaf spot post chlorothalonil

Ramularia leaf spot is major pathogen of barley crops across the temperate regions of the world, reducing yield and quality in grain. The disease is caused by the fungus Ramularia collo-cygni. Research into the development of robust varietal resistance is only just underway and control relies heavily on the use of fungicides. Recently, resistance to the major fungicide groups used in barley has appeared and control relied heavily on the use of the multisite fungicide chlorothalonil. However, this product has lost its approval in the EU and will cease to be an option after May 2020. This paper describes some initial work looking at alternatives to chlorothalonil in a barley disease control programme.