Int. 1. Tropical Plant Diseases, Vol. 13 (1995) : 139-152 Today & Tomorrow's Printers and Publishers, New Delhi - 110 005; (Printed in India) SHEATH ROT OF RICE Ram Singb and D.S. DodanedcbaZYXWVUTSRQPONMLKJIHGFEDCBA CCSHA U, Rice Research Station, Kaul - 132 021, Haryana, India. ABSTRACT Sheath rot caused by Sarocladium oryzae (Sawada ) Gams and Hawksworth is one of the important fungal diseases of rice (Oryzae saliva L.). The disease is gaining importance due to widespread occurrence in almost all rice growing areas of the world. In this paper, the information available on physiology. disease cycle. epidemiology. inoculation technique. host resistance. mechanism of resistance and control measures is reviewed. In addition, future lines of work are also given. SYMPTOMS, DISTRIBUTION AND ECONOMIC IMPORTANCE Rice crop suffers from a number of fungal, bacterial and viral diseases. Among the fungal diseases, sheath rot caused by Sarocladium oryzae (Sawada) Gams and Hawksworth is becoming increasingly destructive in India and other South Eastern countries of Asia (84). The disease is reported from almost all the rice growing areas of the world including Bangladesh, Cameroon, India, Korea, Japan, Peru, Phillipines, South East Asia, Taiwan, Thialand, Venezuela, Vietnam and USA. The disease occurs on uppermost leaf sheath enclosing the young panicles. The lesions appear as oblong or somewhat irregular spots with brown margins and grey centres which enlarge- and cover most of the leaf sheath, resulting in unemerged or partially emerged panicles having unfilled or partially filled grains. PHYSIOLOGY The fungus grows and sporulates best ~ continuous dark at oH 5. 5-n.5 at aroundKJIHGFE I ~ (Jd ~y ,..,. ~:::;I'(~.~ Al<"a~ ~a:,.k +~aru- 21 _ 30°C on potato dextrose aga~ ammonium nitrafe & ammonium sulphate as best C & N sources, respectively (20,37,54, 102,109,119,120). A partially selective medium by