development and in vitro characterization of a Trichoderma-based biopesticide for the management of Fusarium solani...

| The aim of this research was to create a sustainable biopesticide based on Trichoderma intended for use against the pathogen Fusarium solani in tomato. Individual and collective antagonistic potential of six Trichoderma spp. isolates was assessed through in vitro dual culture assays. Individual isolates showed inhibitory rates of 68.2% to 87.4%, while the highest increase in suppressive efficacy to 94.5% was obtained with a synergistic consortium of all six isolates. Based on simple effects analysis, the ideal range for maximum physiological vigor was a 32-45% increase in growth at temperatures of 25-30°C, pH 6, and salinity of 5 dS m⁻¹. Additionally, the presence of 0.75 g L⁻¹ of chelated Fe, Mn, and Zn supplemented to the growth medium increased radial growth and biomass by 28% and 36%, respectively. For the purpose of large-scale production, Ziziphus spina-christi leaf powder was the best substrate, producing the highest propagule density of [Formula: see text] CFU mL⁻¹, which exceeded the productivity of conventional media by 22-40%. A composite formulation of a carrier blend (vermiculite, ground palm fronds, sand, and clay) showed satisfactory biological stability and [Formula: see text] CFU mL⁻¹ biological activity for 360 days of storage at refrigeration temperatures, with more than 75% of its viability maintained. Furthermore, time-series regression analysis confirmed that the temporal loss of fungal viability followed a highly predictable model ([Formula: see text]), while carrier-specific regression modeling demonstrated that the optimized 'mixture' carrier significantly decelerated the decline kinetics compared to the non-formulated control. The results show that the formulated consortium offers an innovative, stable, high quality, and environmentally friendly substitute to chemical fungicides for use in Integrated Disease Management (IDM) programs.