Fungal species belonging to the genus Trichoderma are worldwide in occurrence and easily isolated from soil, and other forms of plant organic matter. Rapid growth rate in culture and the production of numerous spores (conidia). Also, Trichoderma are a rich source of secondary metabolites. This has culminated in the commercial production of several Trichoderma species for the protection and growth enhancement of a number of crops in soil or soilless culture. One of the most interesting aspects of the science of biological control is the study of the mechanisms employed by biocontrol agents to affect disease control and enhance plant growth. Past research indicates that the mechanisms are many and varied, even within the genus Trichoderma. In order to make the most effective use of biocontrol agents for the control of plant disease.