Trichoderma Beyond Biocontrol: Mechanisms and Agricultural Applications

The agricultural value of Trichoderma extends beyond suppression of fungal pathogens. This review examines the mechanisms that support their multifunctionality, including mycoparasitism, competition, antibiosis, hydrolytic enzymes, volatile and non-volatile metabolites, root colonization, hormone-mediated signaling, nutrient mobilization, and microbiome remodeling. Evidence from primary studies shows that selected strains can promote root and shoot development, improve phosphorus acquisition, stimulate antioxidant defenses, alter rhizosphere nutrient availability, and increase crop performance under drought, salinity, heavy-metal stress, and disease pressure. Field studies demonstrate practical potential in seed dressing, soil inoculation, foliar treatment, and microbial consortia, but also show that efficacy is strain-, crop-, formulation-, and environment-dependent. The central challenge is therefore not to identify a universally superior Trichoderma strain, but to match defined traits and formulations to particular crop-soil-climate contexts. Future progress depends on reproducible field validation, mechanistic biomarkers, microbiome-aware formulation, ecological safety assessment, and integration with-not indiscriminate replacement of-other components of crop management.