Biological control of sheath-blight of rice in india with antagonistic bacteria

Strains of fluorescent and nonfluorescent bacteria that were isolated from rice rhizospheres of Southern India and showed antagonism towardsRhizoctonia solani were evaluated for biological control of rice sheath-blight (ShB). Efficient strains of bacteria inhibited mycelial growth ofR. solani, affected sclerotial viabilityin vitro and protected IR 20 and TKM 9 rice seedlings from infection byR. solani in greenhouse tests. Pretreatment of sclerotia in bacterial suspensions resulted in reductions in ShB lesion sizes up to 31 to 44% in IR20 and 58 to 74% in TKM 9 rice. In field plots, IR 50 and TKM 9 rice plants raised from bacterized seeds had 65 to 72% less ShB than those plants from untreated seeds.