Reaction of Durum and Bread Wheat Varieties to Russian Wheat Aphid, Diuraphis noxia Attack under Irrigated Condition

Abstract

The reaction of wheat varieties to Russian wheat aphid (RWA) attack was assessed under field and glasshouse condition at DebreZeit center. In glasshouse test wheat varieties were evaluated in two replications in wooden seedboxes of 60 x 40 x 10cm. The boxes were filled with Vertisoland 20 seeds o f each variety were sown in 10cm row spaced at 5cm. In each seedbox unknown number o f field collected RWA were introduced at one leaf stage. Degree of leaf chlorosis was scored following 1 to 9 scale and leaf rolling either as flat or rolled. In the field screening, seeds (20 to 25 seeds) of each variety were planted in single row of 1m. Plants were inspected weekly from seedling to ear emergence stage and degree of leaf chlorosis and leaf rolling was scored as described in the glasshouse experiment. In all experiments irrigation water was given at weekly interval. In the glasshouse test, only the durum wheat variety Quamy and the bread wheat varieties Galama and Pavon-76 had chlorotic score of 6.0 and were categorized as moderately resistant/
susceptible to RWA, whereas the rest varieties of both wheat types fell in the susceptible category. Under field conditions the durum wheat varieties Asassa, Bichena, Cocorit 71, Hitosa, Kilinto, Werer, Quamy, Robe and Ude and among the bread wheat varieties Bobicho, Danda’a, Dashen, Enseno, Lackech, Tay and Tosa were moderately resistant/ susceptible to RWA, while the rest wheat varieties were susceptible to RWA. All the tested durum and bread w'heat varieties rolled their leaves when attacked by RWA.