Biocontrol Potentials of Individual Specie of Rhizobacteria and Their Consortium against Phytopathogenic Fusarium oxysporum And Rhizoctonia solani

Abstract

Plant Growth Promoting Rhizobacteria (PGPR) are indigenous to soil and the plant rhizosphere and play a major role in the biocontrol of plant pathogens. This present study investigated the biocontrol abilities of individual species of bacteria and their consortium against phytopathogenic Fusarium oxysporum and Rhizoctonia solani. Results from the in-vitro bio-control assay (Hydrogen cyanide, catalase enzyme, lipase enzyme and indole acetic acid production) revealed that four isolates (SB2, PL3, MPT2 and SLD3) exhibited highest and consistent bio-control characteristics. The greenhouse evaluation of these isolates and their consortium (CST) in association with tomato (Beske variety) revealed that isolate SB2 (94.9%) highly reduced the disease caused by Rhizoctonia solani than CST (91.5%), PL3 (90.5%), MPT2 (74.9%), SLD3 (71.5%) and control (0.0%). However, isolate SB2 (100%) apparently reduced the disease caused by Fusarium oxysporum, while isolates PL3, CST, MPT2, SLD3 and control reduced the same disease by 95.7%, 93.0%, 79.0%, 65.2% respectively. Isolates SB2 identified as Bacillus subtilis was the most effective and could serve as biocontrol agents for controlling Fusarium oxysporum and Rhizoctonia solani in tomato cultivation.