Evaluation of biocontrol potential of native Trichoderma isolates against charcoal rot of strawberry

Trichoderma is a highly beneficial species for use in agriculture due to its ability to combat soilborne disease and increase growth in plants. This study investigated the effects of the biological control agent Trichoderma spp. on the incidence of charcoal rot and growth in strawberry plants. Sixteen Trichoderma harzianum (Thr) and three Trichoderma virens (Tvr) isolates were isolated from strawberry fields in different locations in Aydin province. The Trichoderma isolates were identified with molecular methods based on the rDNA internal transcribed spacer region sequences (ITS1/ITS4), and phylogenetic analysis. The Trichoderma spp. isolates growth was evaluated at temperatures ranging from 15 to 45 degrees C on Potato Dextrose Agar (PDA). The optimum growth was observed at 30 degrees C, and no isolates grew at 40 degrees C and 45 degrees C. Tvr4 demonstrated a high performance in inhibiting the mycelial growth of Macrophomina phaseolina by 66.4%, in dual culture assay. Volatile organic compounds antifungal activity Thr15 and Tvr4 suppressed the microsclerotia produced in M. phaseolina by 80.55% and 73%, respectively. A pot trial was carried out in climatic chambers with the following treatments: i) strawberry plant inoculated with Trichoderma spp. (Tr); ii) plant inoculated with Trichoderma spp. and M. phaseolina (Tr + Mp); iii) applying M. phaseolina 15 days after the treatment of Trichoderma (Tr + Mp15). Thr15 gave the maximum (281.95%) fresh weight increase compared to the other tested isolates. Plant mortality in Tr + Mp was significantly reduced with Thr15, Thr14, Thr13, and Tvr2. In the Tr + Mp15 treatment, Thr20 had the greatest reduction in plant mortality and the greatest increase in plant weight.