Sheath blight is a fungal disease caused by Rhizoctonia solani.
Rice sheath blight is an increasing concern for rice production, especially in intensified production systems.
Infected leaves dry out and die more rapidly, young tillers can also be destroyed. As a result, the leaf area of the canopy can significantly be reduced by the disease. This reduction in leaf area are the primary causes of yield reduction.
Why and Where it Occurs
Sheath blight occurs in areas with high temperature (28−32°C), high levels of nitrogen fertilizer, and relative humidity of crop canopy from 85−100%.
Plants are more vulnerable to sheath blight during the rainy season.
High seeding rate or close plant spacing, dense canopy, the disease in the soil, sclerotia or infection bodies floating on the water, and growing of high yielding improved varieties also favour disease development.