Fungal strains within the genus Trichoderma include a wide spectrum of evolutionary solutions that range from very effective soil colonizers with high biodégradation potential, to non-strict plant symbionts that colonize the rhizosphere. Some groups of biotypes within this conglomerate are able to antagonize phytopathogenic fungi by using substrate colonization, antibiosis and/or mycoparasitism as the main mechanisms. This antagonistic potential is the base for effective applications of different Trichoderma strains as an alternative to the chemical control against a wide set of fungal plant pathogens (Chet 1987; Harman and Björkman 1998). As a consequence of the variety of activities displayed by the Trichoderma strain conglomerate, a large range of applications have been developed: the antagonistic potential is the basis for the effective control of a wide set of phytopathogenic fungi and the biodegradative capacity is a source of useful enzymes in different industrial sectors (Harman and Kubicek 1998).