Antagonistic fungus, Trichoderma harzianum UD12-102, exhibited 90% inhibition against Sclerotium rolfsii in vitro and 80% survival of tomatoes infected by S. rolfsii in vivo. Moreover, the antagonistic fungi increased the effectiveness of a commercial fungicide (vitavax) in controlling S. rolfsii in tomatoes. In field experiments, composts were used as carriers for T. harzianum UD12-102 inoculum preparation. Following S. rolfsii inoculation, the survival percentages of tomato plants were not significantly different with all treatments receiving T. harzianum UD12-102 antagonist. However, the inoculum prepared with compost B (inoculated the antagonist at beginning of composting) resulted in a high survival percentage (more than 60%) with 4 weeks of infection, while the survival percentage of control plants dramatically decreased on week 2 (8.35%), and the plants died after 3 weeks due to S. rolfsii. The compost was a good alternative carrier for antagonistic fungi inoculation and was friendly with soil environments
