Yield Loss Assessment of Barley Yellow Dwarf Disease on Spring Oat in Illinois

Abstract

The quantitative relationship between yield of spring oat cvs. Ogle and Noble and incidence of barley yellow dwarf (BYD) disease caused by barley yellow dwarf virus (BYDV-PAV-IL) was studied. Field plots were infested with Rhopalosiphum padi vectoring BYDV-PAV-IL. A linear critical point regression model was developed that related percentage of maximum yield to BYD incidence, assessed by estimating the percentage of plants with BYD symptoms at Feekes growth stage 10.5 in each plot. The model y = 96.9 - 0.45x (r2 = 0.53) best explained the relationship. Test weight was unaffected by BYD. Although Noble consistently sustained higher disease incidence than Ogle, covariate analysis indicated that the effect of BYD on yield was similar for both cultivars. Studies of random versus focus inoculation of Noble oat, designed to determine the importance of compensation in reducing yield loss associated with BYD, indicated that compensation did not play an important role.