Resistance to sharp eyespot in wheat

Abstract

Susceptibility of 16 wheat cultivars to sharp eyespot (caused by Rhizoctonia cerealis) was examined in field experiments Disease incidence varied markedly between experiments but one cultivar Regency consistently had very low incidence which was confirmed in a greenhouse experiment Some cultivars had a high incidence of disease in some field experiments but most cultivars had intermediate incidence A greenhouse experiment provided some evidence for pathogenic variation in R cerealis Monitoring of disease progression in commercial crops confirmed the cultivar differences identified in field experiments Infection was greater in crops sown in midautumn than in lateautumn to winter Primary infection occurred during seedling growth stages with maximum disease incidence occurring by late spring Primary infection developed in resistant cultivars but there was little spread to inner leaf sheaths Selection for resistance to sharp eyespot is feasible in breeding programmes and commercial losses could be reduced by using the more resistant cultivars