Often the fungicide rates that European farmers apply are lower than the labelled rates. The use of ‘adjusted appropriate rates’ is mainly driven by results from field trials showing sufficient control and better net yield responses compared to full rates. The optimal rate depends on several factors of which the intrinsic activity of the active ingredient, the pathogen for control, disease pressure and timing of treatments are the most important. Use of economic thresholds and monitoring systems can improve the use of appropriate rates. Reduced fungicide rates using single-site inhibitors can help to delay resistance development as long as the numbers of treatments are not increased as a consequence of applying reduced rates.