Exemplary embodiments of the present disclosure are directed towards a bio-fungicidal composition comprising atleast one of a culture of an actinomycetes bacteria and a metabolite of an actinomycetes bacteria, wherein the actinomycetes bacteria is atleast one of a Streptomyces atrovirens and a Lechevalieria xinjiangensis. The bio-fungicidal composition is effective against Sclerotium rolfsii infected groundnut plants. The present invention also discloses a method of treating S. rolfsii infected groundnut plants by administering a predetermined amount of the bio-fungicidal composition in the form of a dust, a spray, a powder, a granule or a liquid to the plants.
