Conidia deposition in liquid culture of Trichoderma using starch flour and antifungal activity of the precipitate against Colletotrichum capsici

Colletotrichum capsici is a highly destructive anthracnose pathogen, causing significant losses in chili plants. Trichoderma, an antagonistic fungus commonly mass-cultured, is employed to control anthracnose disease. This research aims to evaluate the efficacy of adding starch for conidia deposition in liquid Trichoderma cultures and to assess the antifungal activity of the sediment on the colony growth of C. capsici. The study utilized a factorial experiment with three types of liquid culture medium (5% tannin, 5% yeast, and 5% yeast + 5% tannin), three types of starch (rice, corn, and tapioca), and three concentrations (5%, 10%, and 20%), each with five repetitions and one control. Liquid culture, composed of a mixture of 2% sucrose with either yeast or tannin from the gambir plant (Uncaria gambir), was inoculated with a blend of three Trichoderma isolates and incubated for 14 days at 150 rpm. Starch was added according to the treatment and then centrifuged at 3000 rpm. The results indicated a significant 8.9–17.8 times log10 increase in conidia concentration after the settling treatment. The type of liquid culture medium and starch concentration significantly influenced the conidia concentration after deposition. The yeast liquid culture exhibited the highest conidia density at 4.96×1010/mL. The starch concentration that produced the highest conidia density after settling was 20%, yielding 4.51×1010/mL. The type of starch did not significantly influence the conidia concentration in the sediment. The methanol extract of sedimented liquid culture, after the addition of 5-20% rice flour from tannin medium, exhibited antifungal activity against C. capsici.