Abstract Winter barley ( Hordeum vulgare L.) is the third most cultivated crop after corn and wheat in Austria but one of challenging for disease control. The foliar pathogen Ramularia collo-cygni B. Sutton J.M. Waller, causing leaf spots (RLS), important diseases barley. In recent years, control has only been achieved using fungicide mixtures including multi-site inhibitor chlorothalonil, howe...