Effect of Russian Wheat Aphid on Yield and Yield Components of Field Grown Susceptible and Resistant Spring Barley

Abstract

Russian wheat aphid, Diuraphis noxia (Mordvilko) (RWA), can be devastating to barley (Hordeum vulgare L.) in the western USA. RWA‐resistant barley germplasm lines have been developed that control RWA without the use of environmentally detrimental and economically expensive insecticides. This study was conducted to determine if seedling RWA resistance ratings, utilized to develop resistant germplasm lines from greenhouse screenings, accurately predict field performance measured as grain yield and to determine the effect of RWA on yield and yield components of RWA‐resistant barley germplasm lines and cultivars differing in seedling RWA resistant rating. Resistant lines and susceptible cultivars were planted at two field locations in Wyoming. Plots were artificially infested with RWA while controls were kept aphid free with pesticide application. Highly resistant lines maintained or increased yield components and grain yield (average grain yield increase 5%) under RWA feeding pressure. Susceptible cultivars had a large reduction in yield components and grain yield (average reduction 56%). The response of moderately resistant and moderately susceptible lines was intermediate and continuous between the resistant and susceptible lines with an average reduction of 20% in grain yield. Seedling resistance ratings accurately predict field performance, providing a more economical, timely, and efficient means of selecting RWA‐resistant germplasm lines for release.