Predisposing effects of Eyespot (Pseudocercosporella herpotrichoides) on Septoria nodorum infection of winter wheat

SUMMARY Plants of two cultivars of winter wheat were inoculated with Pseudocercosporella herpotrichoides at Growth Stage 4 and with Septoria nodorum at Growth Stage 9 or 10.5. Significantly higher levels of S. nodorum developed on the leaves of eyespot infected plants but there was no significant interaction in terms of grain yield. Eyespot infection markedly predisposed the developing seed to infection by S, nodorum. The significance of these results is discussed with reference to the epidemiology of S. nodorum and in relation to the strategy for fungicide control of cereal diseases.