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The study on the management of collar rot of cauliflower, caused by Rhizoctoniu solani by a talc-based formulation of Trichoderma harzianum, was carried out during the early rabi seasons of 2005-06 and 2006-07 under field condition at Mohanpur, West Bengal with isolates of T. harzinum. The seedling dip and soil application of T. harzianum (talc-based) @ 200g per plot significantly reduced the disease incidence (63.6%) at 50 DAT followed by pre-transplanting seedling tip in T. harzianum spore suspension @ 5g/l combined with soil application of talc formulation @ 100g/plot (52.7%) and soil application of the talc formulation of T. Iiarzianum at 200g/plot (50.9%) treatment and there was corresponding yield increase in the respective treatments. The highest population density of T. harzianum was recorded in the plot treated with seedling tip and soil application (210 cfu/g soil) and the lowest in the control plot (7.5 cfu/g soil).

The study on the management of collar rot of cauliflower, caused by Rhizoctoniu solani by a talc-based formulation of Trichoderma harzianum, was carried out during the early rabi seasons of 2005-06 and 2006-07 under field condition at Mohanpur, West Bengal with isolates of T. harzinum. The seedling dip and soil application of T. harzianum (talc-based) @ 200g per plot significantly reduced the disease incidence (63.6%) at 50 DAT followed by pre-transplanting seedling tip in T. harzianum spore suspension @ 5g/l combined with soil application of talc formulation @ 100g/plot (52.7%) and soil application of the talc formulation of T. Iiarzianum at 200g/plot (50.9%) treatment and there was corresponding yield increase in the respective treatments. The highest population density of T. harzianum was recorded in the plot treated with seedling tip and soil application (210 cfu/g soil) and the lowest in the control plot (7.5 cfu/g soil).

Ten isolates of Trichoderma spp. isolated from rhizosphere region Of different crops were evaluated for their ability to produce extracellular hydrolytic enzymes, viz., β-1, 3 glucanase, chitinase and cellulase enzymes with different concentrations ef carbon sources, pM, and temperature levels and the induction of systemic resistance in gram seedlings. Highest chitinase and β-1, 3 glucanase activity were observed in TR2 isolate whereas TH2 isolate exhibited highest activity of cellulase. TH1 and TH5 were the next best isolates in their chtinase enzyme activity. Similarly, TR1 and TH1 isolates followed the TR2 for β-1, 3-glucanase activity. The activity of cellulase was highest in TH2 isolate followed by TH5 and TR2, which were statistically significant. The enzyme β-1,3 glucanase was produce in media with pH 4.0 to 8.0 with an optimum pH5.5. The optimum pH for chitinase and cellulase enzyme activity was recorded at 5.0. With the variable temperatures, i.e., 20, 25, 30, 35 and 40°C, the enzyme activities of all three enzymes showed highest at 30°C. The activities of enzymes β-1,3 glucanase and chitinase was recorded highest at 3.0 and 4.0% concentrations of glucan and chitin, respectively whereat 0.75% concentration of cellulose showed highest cellulase activity. The highest induced resistance by Trichoderma isolates in gram seedlings, was recorded by TR1, through the increase activity of PAL and β-1,3 glucanase and TH1 by enhance activity of peroxidase enzyme.

Ten isolates of Trichoderma spp. isolated from rhizosphere of different crops were evaluated for their antagonistic potential against five soil borne plant pathogens, viz., Rliizoctonia solani, Fusarium oxysporum f sp radicis-lycopersici, Macrophomina phaseolina and Sclerotium rolfsii using dual culture technique and production of volatile and non-volatile antibiotics. Sclerotial antagonism by the biocontrol strains was tested with R. solani and S. rolfsii. The isolate T2, T4 and T7 against Pythium sp., T1, T7 and T10 against F. oxysporum f. sp radicislycopersici, T3 and T9 against R. solani, T7 against S. rolfsii and T6 against M. phaseolina were the most efficient. The highest percentage inhibition of respective pathogen through the production of certain metabolites of Trichoderma isolates was recorded with T7 against Pythium sp, and Fusarium oxysporum sp. radicis-lycopersici, T1 against R. solani, T5 and T6 against S. rolfsii and T9 isolate against M. phaseolina. Trichoderma isolate T9 and T2 were most effective in inhibition of sclerotia formation, production and germination of sclerotia of R. solani and S. rolfsii, respectively.