Causative agent: Rhizoctonia solani (Sexual stage: Thanetophorus cucumeris).

• Affect tillering to heading stage .

Symptoms:

• Initial symptoms are noticed on leaf sheaths near water level.
• On the leaf sheath oval or ellipticalor irregular greenish grey spots are formed.
• As the spots enlarge, the centre becomes greyish white with an irregular blackish brown or purple brown border.
• Sheath blight has symptoms similar to stem rot and stemborer infestation.
• To confirm the cause of disease, check for irregular lesions usually found on the leaf sheaths (initially water-soaked to greenish gray and later becomes grayish white with brown margin).
• Also check for presence of sclerotia.