Abstract:
Sheath rot disease of rice caused by Acrocylindrium oryzae was investigated. The fungus was found to infect rice plants at boot leaf stage. The leaf sheath covering the panicle was found to be comparatively more susceptible to the fungus than the sheath of other leaves. Severe infection caused choising of the whole penicle insids the sheath itself before emergence. The pathogen was isolated from infected tissues of host plants and brought into pure culture. Comparative studies of air isolates of Acrocylindrium oryzae from four rice varieties and two weed hosts did not show much appreciable difference in their morphological characters except light variations in the hyphal thickness and smaller conidial size from those on weed hosts.