Collar Rot Disease of Groundnut: it's Variability and Management

Collar rot disease of Groundnut (Arachis hypogaea L.), caused by Aspergillus niger was observed during survey of Sikar and Jaipur districts of Rajasthan. Samples of collar rot pathogen collected and observed morphological, cultural and pathogenic variability. Isolate AN-01showed maximum per cent disease incidence. Various fungicides tested against Aspergillus niger. Carbendazim 12% + Mancozeb 63% WP gave maximum inhibition of mycelial growth followed by Carboxin 37.5+ Thiram 37.5% WS. In field condition fungicides were applied as seed treatment, Carbendazim 12% + Mancozeb 63% WP was found significant in reducing disease incidence. In bio control Trichodermma harzianum showed maximum mycelial growth inhibition of fungus in in vitro. In pot house conditions T. harzianum + P. fluorescens was found significant followed by T. harzianum, P. fluorescens. The relative efficacy of plant extracts in both in vitro and in vivo conditions, garlic clove extract was found significant followed by Neem leaf extract. In field conditions, relative efficacy of organic amendments and bio-agent, Neem cake + soil application with T. harzianum was found significant followed by FYM + T. harzianum.