Sheath rot (ShR) has been known almost for a century, but was restricted to
South East Asia and the Indian Subcontinent. Occurrence of the disease became
widespread in mid 1970s when the high yielding technology was introduced by
planting improved N-responsive cultivars. Today, ShR is a major constraint in
rice production in irrigated as well as rainfed, upland rice. The disease has
been reported in many rice growing countries and its spread causes concern
because of its transmission and dissemination. The causal fungi, Sarocladium
spp, have biological association with rice tungro virus, mites, stem-borers and
mealy bugs and therefore increases the ShR incidence as well as severe