The experiment was conducted at Jute Agriculture Experimental Station, Jagir, Manikganj to study the diseases severity (die back, seedling blight) of tossa jute. Four tossa jute varieties (O-9897, O-72, O-795 and OM-1) and three harvesting time (15, 45, 75 days after sowing (DAS)) were considered as experimental treatments. The experiment was designed RCBD with three replications. Diseases severity was calculated by manually counting of seedling blight and die back diseases infected plants per unit area. Diseases severity found maximum in V1 and V3 varieties and seedling blight found maximum at 15 days aged plant whereas die back found maximum at 45-75 days old tossa jute plants.

Key words: Jute, Corchorus olitorius, diseases severity, die back.