Five Trichoderma spp. were isolated from the old alluvial zone of North Bengal and their biocontrol activity were tested in dual culture and found effective against soil-borne plant pathogens, namely, Fusarium oxysporum f. sp. ciceri (Padw.) Matuo. and Rhizoctonia solani Kühn. Efficacy in plant growth promoting activity of all the isolates was also tested on cauliflower (Brassica oleracea var botrytis L.), chilli (Capsicum frutescens L.) and tomato (Lycopersicon esculentum Mill.) with culture filtrate of biocontrol agents and found both positive and negative effect on seed germination, plant growth and vigour. Maximum increase in germination by 13.64% (chilli), shoot length by 59.69% (tomato), root length by 84.51% (cauliflower) and biomass by 46.55% (cauliflower) were obtained by the isolate B16 followed by B14 and B13. However, the isolate, B18 showed negative result with maximum reduction in germination by 25.56% (cauliflower), shoot length by 67.06% (cauliflower), root length by 88.50% (cauliflower) and biomass by 34.91% (chilli). Whereas, in the field experiment with talc based bioformulation (3x108 cfu), all Trichoderma isolates, particularly the isolates, B18 and B16, were found effective to increase yield (12.50% to 23.14%) and reduce rice sheath blight disease incidence (46.32% to 70.54%) over check plot significantly. Again, the efficacy of the biocontrol agents was significantly greater in the block with green manured than the block without green manured. Application of hexaconazol 5% EC@ 2.0 ml litre-1 and carbendazim 50% WP @ 1.0 ml litre-1 also reduced the sheath blight disease incidence by 53.25% and 56.86% over the check plot respectively. It was interesting to observe that all biocontrol agents were found effective significantly than the fungicides. Therefore, the fungal biocontrol agents, particularly, B18 and B16 could be used as biofungicide as well as biofertilizer for the management of sheath blight of rice.