Banded leaf and sheath blight

Anamorph: Rhizoctonia solani f. sp. sasakii
(Teleomorph: Corticium sasakii, syn. Thanatephorus cucumeris)

Nature of damage

  • The main damage is a brownish rotting of the ears.
  • These show conspicuous, light brown, cottony mycelium with small, round, black sclerotia.


  • True to the name, this disease develops on leaves and sheaths.
  • Symptoms are characteristic concentric spots that cover large areas of infected leaves and husks.

Factors favoring development

  • Humid conditions and irrigated fields are highly favorable for the disease.
  • Additionally, high crop densities impact disease severity.

Geographical distribution

  • Devastating epidemics of BSLB have been reported from Bhutan, China, India, Indonesia, Nepal, the Philippines, and Vietnam.
  • Additionally, the disease has been reported in several African and Latin American countries.
  • Generally the disease is most prevalent and severe in Asian countries where rice is intensively cultivated.