Studies on Antagonism of Trichoderma and Gliocladium species Against Rhizoctonia solani of Rice

Antagoniastic fungi, Trichoderma viride, T. harzianum, T. koningii and Gliocladium virens were evaluated against Rhizoctonia solani, the sheath blight pathogen of rice. In dual culture technique, T. viride (Coimbatore - 2 isolate) was superior in inhibiting the growth of the pathogen followed by T. harzianum (Coimbatore), G. virens (Pantnagar) and T. harzianum (Pantnagar). Lysis of the pathogen with biocontrol agents was observed. Many bioagents were superior in controlling sheath blight disease when sprayed 24 h after inoculation of the plant with the pathogen than sprayed 24 h before inoculation. Maximum disease reduction was observed in T. koningii (Delhi isolate) followed by T. viride (Coimbatore-2), T. viride (Delhi) and T.viride (Coimbatore-1), when sprayed 24 h after inoculation. In both the treatments T. koningii showed superiority over other bioagents, while the performance of G. virens was very poor irrespective of the treatments although the performance was better in inhibiting the pathogen in dual culture experiments.