Management of sheath blight disease of rice through bio control agents in west central table land zone of Odisha

Among different fungal diseases of rice, sheath blight caused by Rhizoctonia solani Kuhn has currently become one of the most important diseases on all the major high yielding rice varieties. Because of lack of resistant donor lines no variety was found as completely immune to the disease. Till date, chemical control is the most widely used means to control the disease which may have several adverse effects on the environment. Considering the environmental safety, biological control is the most feasible method of disease control. Keeping this in view, field experiment was conducted to study the efficacy of bio control agents, Trichoderma viride and Pseudomonas fluorescens against sheath blight disease of rice. The bio control agents were applied as seed treatment and in combination of seed treatment and foliar spray and were also compared with standard chemicals like validamycin @ 2.5 ml/l and propiconazole @ 1ml/l. The percent disease index (PDI) as well as the growth parameters of individual treatments were recorded. The yield of the crop in q/ha as well as 1000 grain weight were also worked out. The result revealed that, seed treatment + 3 spraying with T. viride @ 1% was the most effective bio control treatment recording 10.93% pooled PDI against 34.41% in control plot and its performance was at par with the standard fungicide propiconazole @ 1%. The treatment also exhibited maximum increase in all the yield attributing factors recorded and gave a yield increase of 41.1% over control. The 1000 grain weight was also found highest (22.2 g) among all the treatments.