POTENCIAL DE DIFERENTES ISOLADOS DE Trichoderma SPP. NO CONTROLE DE FITOPATÓGENOS E PROMOÇÃO DE CRESCIMENTO EM PLANTAS

Abstract

This study evaluated the potential of native Trichoderma spp. isolates for the biological control of phytopathogens and promotion of growth in soybean and maize. Thirteen isolates obtained from soils in Goiás state were tested against Macrophomina phaseolina, Macrophomina sp., Fusarium sp., and Rhizoctonia solani. Laboratory assays included dual culture tests, antagonism scales, sporulation capacity, mycelial growth, and parasitism. Inoculum was produced by solid-state fermentation on parboiled rice and converted into conidial suspensions. Spore viability was monitored for up to 35 days under refrigerated (4°C) and frozen (−80°C) storage. Field experiments in randomized blocks were carried out during the 2023/24 season, with individual and combined isolate treatments compared with a commercial product and a control. Plant height, root and shoot dry mass, thousand-seed weight, and productivity were evaluated. Isolates P3, P6, and P10 showed vigorous growth, high sporulation, and parasitism against multiple pathogens. Spore viability remained above 70% under refrigeration for up to 21 days, while freezing drastically reduced survival after 14 days. In the field trial P3 and P6 application, alone or in combination, significantly increased plant height, dry biomass, and yield in soybean and maize, outperforming the control and performing similarly or better than the commercial product. These results indicate that native isolates of Trichoderma spp., particularly P3, P6, and P10, have high potential as biocontrol agents and bio-stimulants. They represent promising candidates for the development of biological formulations aimed at integrated disease management and sustainable agricultural systems in the Cerrado. Keywords: Trichoderma spp., bioprospecting, antagonism, bioinputs, biological control.