In vitro Evaluation of Medicinal Plants’ Crude Extract against Black rot (Xanthomonas campestris pv. Campestris) of Cabbage

Application of synthetic chemicals is one o f the primary options for the control of the black rot disease. However, the environmental hazards and economic unfeasibility associated with them necessitate the search for relatively safe natural products with the ability to show antibacterial effects. With this view, an exper iment wa s conducted to evaluate the effect of plant extracts on black rot o f cabbage, Xanthomona s c ampes tris pv. Campestris (XCC). XCC was isolated f rom infected c abbage leaves. The isolated pathogen grown in pure culture was maintained in Yeast Extract Dextrose Calcium Carbonate Aga r (YDC) at 4"C. The in vitro test wa s conducted to evaluate four methanol plant extract for their antibacterial effects against XCC using the paper disc technique. The minimum inhibitory concentration o f methanol extracts o f Phytolacca, dode candra, Ruta chalepensis, Oc imum lamiifolium and Vernonia aniygdalina were 1.5. 2, 3 and 5%. respectively. In the in vitro trial, berries extracts o f P. dode candra at 10% concentra tion (10.88mm) showed the highest growth inhibitory effects as compa red to other plant extracts, followed by R. chalepensis at 10% concentra tion (8.52mm) . In general, this study demons tra ted that plant extracts such as P. dodecandra, R. chalepensis, O. lamiifolium and V. aniygdalina, inhibits the growth o f XCC. Pest Managment Journal of Ethiopia , Vol. 20 (2017): Pest Managemernt Journal of Ethiopia