BIOLOGICAL-CONTROL OF FUSARIUM ROOT-ROT OF BROAD BEAN

An isolate of a soil-inhabiting Bacillus subtilis which was parasitic to Fusarium solani (Mart.) Sacc. in culture, was also an effective biological control agent to this pathogen of broad bean in greenhouse studies. Bacterium applied as seed treatment significantly reduced seed colonization by the pathogen and root rot disease of broad bean. B. subtilis inhibited the growth of the pathogenic fungus on potato dextrose agar. The culture filtrate of bacterium caused significant reduction in percentage germination of spores of the fungus. These indicate that B. subtilis may produce some metabolites which inhibit the fungus. The significance of this antagonistic bacterium is discussed in relation to the control of root rot disease of broad bean.