In vitro experiment was carried out to see the effect of saw dusts of Pinus kesiya, Shorea robusta, and Callicarpa arborea on Trichoderma harzianum, isolate TH-13 mass production, along with its biotization effect on Capsicum chinensis Jacq. "Bhut Jolokia." Early mycelium initiation (2 days) occurred in S. robusta followed by P. kesiya and C. arborea (3.5 days). The sporulation was observed earlier in S. robusta (100% after 6 days) than P. kesiya (33.4% after 8 days) and C. arborea (16.7% after 9 days) but no sporulation was observed in control. The complete sporulation was also earlier in S. robusta (100% after 10 days) than P. kesiya (33.4% after 15 days) and C. arborea (16.4% after 18 days). Higher conidial yield (86 × 10(6)) was also in S. robusta than P. kesiya (70 × 10(6)) and C. arborea (45 × 10(6)), respectively. The increase in height (60-70 cm), number of leaves (600-650), and yield of chili (120-150 fruits) were also more in inoculated C. chinensis seedlings than control. It is concluded that S. robusta saw dust is the best substrate for mass production of compost fungal activator and can be used in nursery practices for quality stock production of various crops/plantations.