Abstract: The use of specific biological control agents (BCAs) has been revealed as a suitablealternative to the intensive use of fungicides in agriculture. Despite the use of these BCAs, thecontrol of diseases in nursery plants often fails. In this work, we will present several strategies soas to improve and optimize the use of one of the most efficient antagonist, Trichodermaharzianum. The development of molecular methods such as qPCR and qRT-PCR, has providedpowerful tools for monitoring both active and non-active forms of T. harzianum in pure culturesand nursery substrates. Moreover, proper isolates of T. harzianum have been screened andselected according to the highest biocontrol potential and effectiveness against the target disease.To enhance the biocontrol effect of T. harzianum, enrichment with chitin-rich wastes has beensuccessfully applied, decreasing the incidence of the pathogen.