ABSTRACT

Soybean (Glycine max (L.) an important oil seed crop belonging to family Fabaceae is affected by charcoal rot caused by Macrophomina phaseolina which led to yield loss of 70 per cent or more. The present study focused on survey for the incidence of disease, molecular identification of the pathogen, in vitro and field efficacy of bioagents, botanicals and ITK’s against M. phaseolina. The highest disease incidence was observed in Dharwad district with the mean disease incidence of 14.03 per cent followed by Belagavi (11.06 %) and least was recorded in Bagalkote district (8.85 %). Among various district surveyed highest disease incidence (24.95 %) was observed in Dharwad, followed by Anigol (23.53 %) from Belagavi district. The variety DSb 21 was moderately susceptible and recorded maximum disease per cent (16.12 %). The molecular identification using ITS 1 and ITS 4 primers revealed that the fungal isolate was M. phaseolina with 97.93 per cent similarity with M. phaseolina MP 14 isolate from Dharwad with accession number OM674337.1. T. harzianum (MH027645.1) IOF strain, neem oil (Azadirachtin 1%) and Panchagavya @ 10 per cent showed significant inhibition of M. phaseolina under in vitro conditions. These were further evaluated for their effectiveness under laboratory and field conditions. Under laboratory conditions T. harzianum (MH027645.1) IOF strain @ 10 g/kg seeds recorded the highest germination per cent (83 %), seedling vigour (2697) and least per cent of seed infection (4.7 %). In field conditions, the seed treatment with T. harzianum (MH027645.1) IOF strain @ 10g/kg of seeds + soil application of vermicompost enriched with T. harzianum (MH027645.1) IOF strain (100 kg + 1kg) @ 250 kg/ha recorded least per cent disease incidence (11.55 %) at 85 DAS with the highest yield and B:C ratio of 26.66 q/ha and 2.85 respectively compared to other treatments.