Distribution, Composition and Economic Importance of Diseases and Insect Pests of Castor and Mulberry Plants in Some Parts of Ethiopia

Abstract

Survey was carried out to study the distribution, composition and economic importance of diseases and insect pests of castor and mulberry plants between 2009 and 2011 in some parts of Ethiopia. From the surveyed areas, insect pests and diseased plants were observed and distinguished at their station. In addition, sample pests and infected plant parts were taken and examined in Melkassa Agricultural Research Center. The result showed that Mealy bugs (Paracoccussp.), Scale insects (Aonidiella sp. and Coccus sp.), Semi looper (Achoea sp.), Common bugs (Acrosternum sp.), Jassids (Empoasca sp. and Eurymela sp.), Hairy caterpillar (Euproctis sp.), Stinkbug (Nezara sp.), and grass hoppers (Ornithacris sp.) were observed as insect pests on castor with different rate of infestation and damage level. Very high infestation and damage level were found from mealy bugs, scale insects and common bugs. The most widely distributed insect pests were common bugs, jassids and Semi looper which were recorded from most of the surveyed areas. Mulberry borer (Apriona sp.), common jassid (Eurymela sp.), soft scale insects (Pulvinaria sp.) were recorded as insect pests on mulberry plant. Among castor diseases Alternaria sp., Fusarium sp., Melampsora sp.. Cercospora sp. and Xanthomonas sp. were recorded. Incidence and severity were high when castor plant was infected with Alternaria sp., Cercospora sp. and Melampsora sp. All causal organisms of castor diseases were distributed in the surveyed areas. Among diseases Cercospora sp., Phyllactinia sp. (powdery mildew), and Pseudomonas sp. was found to infect mulberry cultivars. The major and widely distributed disease in mulberry was Cercospora sp.