Biological management of root and collar rot of cauliflower (Rhizoctonia solani) by a talc-based formulation of Trichoderma harzianum Rifai.

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).