Yield‐loss Relationships in Cereals

SUMMARY The results of six studies using precision methods to obtain quantitative yield-loss relationships are reported. Losses ranged from 100 per cent for Pyrenophora graminea on barley, to 51 per cent in a simulated grazing trial on wheat, 20 and 8 per cent respectively for Fusarium nivale and Rhizoctonia solani causing culm lesions on wheat, and 12 per cent for yellow rust on barley. Evidence of interactions between seed treatment with mercury, F. nivale infection and mildew on barley is also presented, in which seed treatment was beneficial regardless of seed infection, and F. nivale intensified the loss due to mildew.