Exploring Biochar as a Sustainable Strategy for Suppressing Macrophomina Phaseolina Causing Root and Stem Rot of Sesame

Sesame (Sesamum indicum L.) is an important oilseed crop widely grown in tropical and subtropical regions. However, its productivity is significantly affected by root and stem rot caused by Macrophomina phaseolina. This soil-borne pathogen survives in soil through persistent microsclerotia and leads to severe yield losses, especially under high temperature and moisture stress conditions. The present study was conducted to evaluate the effectiveness of eucalyptus wood biochar, applied alone and in combination with bioagents, for managing root and stem rot of sesame under controlled conditions. The experiment was carried out in a Completely Randomized Design (CRD) with seven treatments and three replications. Biochar was applied at different concentrations (5 g/kg, 10 g/kg, and 30 g/kg soil) alone and in combination with Trichoderma viride, Pseudomonas fluorescens, Bacillus subtilis, and Jawahar Mycorrhiza. Observations on germination percentage, shoot and root length, and percent disease incidence were recorded at 30, 45, and 60 days after sowing (DAS). Among all treatments, biochar (5 g/kg soil) combined with T. viride was most effective, recording 88.77% disease reduction over control at 60 DAS along with maximum germination (66.60%) and improved plant growth. Higher biochar concentration (30 g/kg soil) was comparatively less effective, indicating a dose-dependent response. Overall, biochar integrated with beneficial bioagents proved effective in suppressing M. phaseolina and enhancing sesame growth.