The concept of biological control embodies the introduction of antagonists into cropping systems and also manipulation of the environment to favor resident beneficial microorganisms by crop rotation, residue management and a wide range of cultural practices. Groundnut (Arachis hypogaea L.) an important oil seed crop in India is affected with several soil borne diseases. As a result heavy yield loss occurs. Among these diseases two soil borne pathogens viz. Sclerotium rolfsii and Rhizoctonia solani causes severe crop destruction in Madurai district, Tamilnadu, India.