In-Vitro antagonistic study of indigenous

Leaf mold disease in tomato (Lycopersicum esculentum), caused by Passalora fulva, is a destructive pathogen that leads to leaf wilting, defoliation, and reduced crop yield. In Indonesia, this disease is increasingly problematic, and current control methods rely on chemical fungicides that harm soil and the environment. This study investigates the antagonistic potential of indigenous Trichoderma sp. isolated from the rhizosphere of bamboo, mahogany, and coffee trees in Temanggung, Indonesia. Fungal isolates were cultured on Potato Dextrose Agar (PDA) and identified macroscopically and microscopically. Using a Completely Randomized Design (RAL), dual culture and culture filtrate inhibition tests were conducted on one control and 3 treatments with 3 replications. Data were analyzed via ANOVA and further tested using the 5% Least Significant Difference (LSD) method. Results showed significant inhibition of P. fulva by Trichoderma sp., with dual culture inhibition rates of T1 (85.4%), T2 (83.4%), and T3 (80.6%), and culture filtrate inhibition rates of T1 (46.7%), T2 (27.1%), and T3 (33.2%). The bamboo rhizosphere isolate (T1) demonstrated the highest antagonistic activity in both methods. These findings suggest that Trichoderma sp. from bamboo rhizosphere serves as a natural biocontrol agent and act as an eco-friendly alternative to chemical fungicides.