Management of Common Bacterial Blight (Xanthomonas campestris pv. phaseoli (Smith) Dye.) of Common Bean (Phaseolus vulgaris L.) Using Resistant Varieties and Bactericidal Chemicals in Southern Ethiopia

Common bacterial blight (CBB) caused by the bacterium Xanthomonas campestris pv. phaseoli is a major disease of common bean affecting its production in southern Ethiopia. This study was conducted to determine the effect of variety, seed treatment and foliar spraying frequencies of bactericide on disease severity, yield and yield components of common bean. Field research was conducted at Hawassa agricultural research center during 2017/18 main cropping season using Hawassa dumme and Mexican-142 varieties. Streptomycin seed treatment was integrated with Kocide-101 foliar spraying frequency at the rate of 2.31 kg ha-1 at two, three and four week’s intervals. The design was randomized complete block design arranged in factorial with three replications. Due to the effect of variety, severity was reduced by 17.2% and the mean seed yield was increased by 18% over Mexican 142. Seed treatment reduced disease severity by 10.7% and increased yield by 24.2% as compared with other untreated control. Two week interval spraying reduced severity upto 31.8% and increased yield upto 42.3% over untreated control. Integration of variety and seed treatment with two week interval foliar sprays gave higher marginal benefit and higher marginal rate of return.