Sheath blight (ShB) of rice is an economically important disease in all crop growing areas of the world. Significant grain yield losses were reported due to ShB when susceptible varieties were grown (Prasad and Eizenga, 2008). The disease is caused by a soilborne fungal pathogen, Rhizoctonia solani Kuhn. The pathogen survives as sclerotia and mycelia in plant debris and on weeds in rice growing areas (Kobayashi et al, 1997). In temperate regions, the
primary source of inoculum is sclerotia produced in previous rice crops (Kozaka, 1961). Germplasm of high genetic resistance for ShB is not available, and the disease is currently managed through use of chemical fungicides (Pal et al, 2005).