Evaluation of Barley Varieties against Russian Wheat Aphid (Diuraphis noxia M.) under Greenhouse Condition

Abstract

Russian wheat aphid (RWA), (Diuraphis noxia M.) is the major insect of barley in many areas in the world. It was reported in the Wukro (Atsbi) and Adigrat regions of northern Ethiopia in 1972/73 and western Welo region of northwestern Ethiopia in 1974. RWA causes severe damage to barley in the highlands of Ethiopia. Few information is available on the control of this pest in the country. An experiment was conducted in the 2013/2014 off-season at South Gondar Zone (Debretabor). The experiment aimed at evaluating some resistant sources of barley varieties against RWA was conducted in greenhouse conditions of the university site. Five barley varieties (Burton, RWA-1758, 3296-15, Holker and local susceptible) were studied in complete randomized design. The number of aphids per tiller decreased on the resistant varieties as compared to the control; this is probably due to their own inherent resistant character. There were also significant differences(p<0.001) in mean chlorosis, leaf rolling, RWA population, leaf number per tiller and tiller number per plant among the resistant and the susceptible varieties. Severe plant damage (36.6%) was observed on the local barley variety while the least damage was observed on Burton, followed by RWA-1758. Burton and RWA-1758 were therefore highly resistant and moderately resistant, respectively. The damage to barley lines 3296-15 and Holker was greater than to Burton and RWA-1758 and highly lower than the local one. From the result resistant varieties provided much lower damaged plants and population of RWA per tiller and much higher yield components than the susceptible varieties. This indicates that the most effective approach in managing the RWA is the use of resistant variety. Hence it is concluded that use of host plant resistance is an important avenue for RWA management, and is one of the favored control options for aphids.

Keywords: Russian wheat aphid, Diuraphis noxia, barley, Hordem vulgare, host resistance