Growth of Trichoderma viride as Influenced by pH, Temperature, Botanicals, Fungicides and Mutagenic Agent

The present investigation was on the growth of Trichoderma viride Pers. ex. Grey effective against Botrytis ricini (castor grey rot) as influenced by pH of culture medium, incubation temperature, botanicals/fungicides and exposure to physical mutagenic agent, gamma rays. T. viride grew under wide pH range of 4.0 to 9.0 with optimum pH being 5.0 to 6.0. Maximum sporulation occurred at pH 6.0. Incubation temperature of 25⁰C was best for the growth of T. viride. The isolate was found compatible with 10% leaf extracts of Lantana camera, Datura stramonium, Azadirachta indica, Curcuma longa, Memordica dioica (Kakrol), Emblica indica (Aonla) and Ricinus communis and common fungicides viz., mancozeb 0.25%, thiram 0.3% and copper oxychloride 0.3% but not with carbendazim 0.1%, benomyl 0.1%, hexaconazole 0.2% and thiophanate-methyl 0.1%. Stable mutants were obtained by exposing the isolate to gamma rays and designated as TV1, TV2, TV3, TV4 and TV5, which differed in their antagonistic ability against B. ricini. Mutant TV4 recorded maximum inhibition of B. ricini (88%) followed by TV5 (87%) in comparison to wild isolate designated as TV6 (82.6%). Further, TV4 and TV5 were compatible with 0.3% captan and 0.01% carbendazim. Thus, mutants TV4 and TV5 were superior to wild isolate.