Abstract: A biocontrol agent and a method of use thereof for controlling diseases caused by fungal pathogens in plants. In one aspect of the invention, novel strains of Gliocladium roseum exhibiting antagonistic effects against plant pathogens are used as biocontrol agents. Most preferably, a novel strain Gliocladium roseum ACM941 (ATCC #74447) is used in a treatment effective against fungal pathogens of plants. The biocontrol agent of the present invention may be used in the treatment of seeds, soil or plants to effectively protect against plant diseases caused by fungal pathogens. The biocontrol agent is particularly effective against fungal infections of pea, bean, canola, wheat, barley, beet, broccoli, brussel sprouts, cabbage, canola, califlower, cucumber, egg plant, pepper, tomato, marigold and other horticultural and ornamental plants, caused by Alternaria alternata, Aphanomyces euteiches, Ascochyta spp., Bipolaris sorokiniana, Fusarium graminearum, Fusarium oxysporum f.sp. pisi, Fusarium solani f.sp.