STRAINS OF BRADYRHIZOBIUM FROM TROPICAL FORAGE LEGUMES INHIBIT RHIZOCTONIA-SOLANI AG-1 IN-VITRO

Fifteen strains of Bradyrhizobium from the Centro Internacional de Agr icultura Tropical (CIAT) collection were screened for their antifungal activities on nutrient agar plates. In vitro tests show that Bradyrhi zobium can inhibit mycelial growth, reduce or prevent sclerotial forma tion, and inhibit sclerotial 'germination' in Rhizoctonia solani AG-1. In addition, cell-free culture filtrates of three strains of Bradyrhi zobium had inhibitory effects on the growth of the bacteria Escherichi a coli DH5 alpha and Xanthomonas campestris pv. phaseoli CIAT 555. Thi s is the first demonstration of fungal/bacterial inhibitory activities of strains of Bradyrhizobium isolated from tropical forage legumes.