Introduction. Trichoderma asperellum strain T109 has shown great antagonism activity in vitro against phytopathogenic fungi. However, it is necessary the real understand of this strain into spatial organiza- tion in soil under in vitro and field conditions to know the population density. Objective. The aim of this study was to evaluate different inoculum concen- trations and frequencies of application in Trichoder- ma asperellum T109 bioavailability. Materials and