Department of Biological Sciences, CBSH, G.B. Pant University of Agriculture & Technology, Pantnagar, India

 This study was intended for monitoring the optimum temperature of Trichoderma harzianum. Optimum temperature for Trichoderma harzianum  was estimated by two parameter; one was monitoring the radial growth rate and colony morphology in culture plate at 25°C, 30°C, 37°C and 45°C and second was calculating the population dynamics in inert carrier at 4°C, in shade (31±2°C) and in direct sunlight (42±2°C). In this study we used sterilized compost manures as inert carriers which were as follows: 1) JNMsC (Jatropha seed cake, Neem cake, Mushroom spent, Cuscuta reflexa) 2) FYM (Farm Yard Manure) 3) CPP-SUPA and 4) Jatropha seed cake and cow dung (JC). T .harzianum hyphal extension grown faster at 25-30°C, slower grown at 37°C and no growth was observed at 45°C after six day of inoculation. Population dynamics was maximum in shade followed by 4°C. In sun light population dynamics was decreased very fast in all substrates. Hence optimum temperature of Trichoderma harzianum was found between 25-30°C i.e. approx. 28°C by radial growth and population dynamics.

 Keywords: Trichoderma harzianum, mycelium growth, temperature, compost manure, population dynamics.