Cross-tolerance of Trichoderma harzianum rifai to fungicides

The isolate of Trichoderma harzianum Rifai tolerant to fungicides viz., Captafol, Captan, Thiram and Carbendazim were developed in vitro by gradual transfer of the growth from lower to higher concentrations of respective fungicides. Cross-tolerance of T. hazianum between captafol and captan showed adaptation capability to both the fungicides whereas, it showed adaptation capability to captan only when tested between thiram and captan. In cross-tolerance study between captafol and thiram, the isolate which showed tolerance to higher concentrations of captafol was not tolerant to thiram. However, the isolate that adapted to thiram showed adaptation capability to captafol also. Similarly, carbendazlm tolerant isolate was more tolerant to captan also. But. the isolate tolerant to higher concentrations of captan was not tolerant to carbendazim.