Belete T and Bastas KK
Common bacterial blight (CBB) is the most devastating factor that affects common bean crops in all common bean growing areas. This review was to review with an objective of reviewing the biology, economic importance of CBB of common bean crop disease and its management options, with an emphasis on the future research direction and priorities. CBB disease, caused by the gram-negative bacterial pathogen Xanthomonas axonopodis pv. phaseoli (Xap) and its fuscans variant Xanthomonas fuscans subsp. fuscans (Xff) is the major bottleneck in bean production in the world as well as in Ethiopia. It is a serious bacterial disease of common bean which causes lesions on the leaves, stems, pods and seeds of the plant. The disease affects seed quality and can reduce yield by up to 45%, may be more in susceptible cultivars. CBB is very difficult to control due to seed-borne nature of the bacteria and its capacity to produce huge amounts of secondary inoculum. Since the disease is very important in causing economic losses of yields on bean crop, developing and using effective and appropriate management options is unquestionable. Using resistant varieties supplemented with chemical seed treatment and proper cultural practices could be the best alternative options in managing common bacterial blight of common bean and avoiding yield loss. In general, integrated disease management is the preferred strategy because of increased understanding on residual effects of chemical control on non-target organisms and environment as well as the limitation of a single alternative management option to achieve the same level of control and reliability as that of chemical. In the case of Ethiopia, emphasis should be given to developing multi line resistance varieties by suitable breeding practice and developing molecular markers to enhance marker assisted selection.