Carbendazim Tolerant Induced Trichoderma Viride for Integrated Management of Wire Stem of Cabbage
An attempt was made in the present investigation to formulate an integrated management strategy against wire stem of cabbage caused by Rhizoctonia solani Kuehn. Induction of Trichoderma viride to carbendazim was done through repeated exposure to the fungicide. Out of the four selected induced strains of T. viride to the systemic fungicide carbendazim, all the strains were found sensitive to the fungicide at different levels of concentration. However, one of the carbendazim tolerant strain of the antagonist (TV-S-4) could tolerate the fungicide at 10 µg a.i./ml indicating that T. viride and carbendazim could be successfully integrated against the pathogen at low concentrations of the fungicide. Higher antagonistic activity, faster growth and increased production of antifungal volatile substance were also observed in TV-S-4. The pot trial conducted with different treatment combinations of carbendazim (reduced dose) with T. viride revealed maximum (90.72%) control of the disease could be achieved when the fungicide (@ 0.05%) was integrated with the bioagent TV-S-4 @ 5g/ kg of pot soil followed by application of another carbendazim tolerant strain of the antagonist (TV-S-3) and carbendazim @ 0.05%. when carbendazim was applied @ 0.1% the percent plant mortality was 23.64 as compared to 85.21% in the untreated inoculated control. Amongst the treatments tested, application of the bioagent (TV-W) alone was found least effective.