Compatibility Studies of Trichoderma harzianum Isolate with fungicides used against soil borne disease in Coorg Mandarin-Pepper-Coffee Plantations.

Abstract

An in vitro bioassay was undertaken to record the compatibility of local isolate of Trichoderma harzianum with fungicides used in coorg mandarin-pepper-coffee plantations. Eight non-systemic, 10 systemic and 9 combi products fungicides were evaluated against Trichoderma for radial growth inhibition on PDA medium using poisoned food technique. Contact fungicides at selected concentration were found to be safer than systemic and combi products except Chlorothalonil. In systemic fungicidal treatments complete mycelial inhibition of T. harzianum was recorded in Carbendazim, Hexaconazole, Thiophenate Methyl and Propiconazole. In combi products T. harzianum was not compatible with Hexaconazole 4%+Zineb 68%, Carbendazim 12 % + Mancozeb 63 %, Tebuconazole 50 % + Trifloxystrobin 25 % WG, Pyraclostrobin 133g/l + Epoxiconazole 50 g/ l and Captan 70 % + Hexaconazole 5% WP in any level of selected concentrations. Whereas, reduction in sporulation of T. harzianum was recorded in Metalaxyl 4%- Mancozeb 64% WP and Fenamidone 10 % + Mancozeb 50 WG with increase in concentrations.