Trials over 8 years in Northern Ireland with a range of fungicides, applied at a range of doses, to spring barley showed a reduction in disease and increase in green leaf area and yield, particularly from 1993 to 97, when mildew (Blumeria graminis f.sp. tritici) was the main disease. Fungicides in those years had considerable effect even at low doses. In the latter years of the project, there was relatively little mildew or leaf blotch (Rhynchosporium secalis) and the effect of fungicides was less. Results generally indicate that the potential of disease resistance of cultivars should be fully exploited and prophylactic spraying at present is unlikely to be profitable.