Comparative efficacy of eco-compatible disease management strategies combined with gas chromatography-mass spectrometry profiling of a potent natural formulation against Sclerotinia sclerotiorum infecting rapeseed-mustard (Brassica juncea (L.) Czern.)

Rapeseed-mustard (Brassica juncea (L.) Czern.) is a major oilseed crop that contributes significantly to edible oil production and farm income. However, its productivity is greatly affected by stem rot caused by Sclerotinia sclerotiorum (Lib.) de Bary, a destructive pathogen capable of causing severe yield losses under favourable environmental conditions. The present study evaluated eco-friendly disease management approaches involving natural formulations, biological control agents and alcoholic plant extracts as sustainable alternatives to conventional fungicides. In vitro studies revealed that Propiconazole 11.9 % + Azoxystrobin 7.1 % SE, Thiophanate methyl 70 % WP and Difenoconazole 11.4 % + Azoxystrobin 18.20 % suspension concentrate (SC) completely inhibited the growth of S. sclerotiorum at 150 ppm. Among the natural formulations, Jeevamrut showed the highest mycelial growth inhibition (63.17 %). Among the bioagents, Trichoderma asperellum was the most effective, recording 76.56 % inhibition of the pathogen. Among the alcoholic plant extracts, Melia azedarach L. exhibited the highest antifungal activity, suppressing fungal growth by 40.16 % at a 50 % concentration. Field experiments demonstrated that the integrated application of Jeevamrut, T. asperellum and M. azedarach provided the highest disease control (73.28–82.84 %), surpassing the chemical check. Gas chromatography–mass spectrometry analysis of Jeevamrut identified 22 bioactive compounds, including fatty acid esters, phenolics and antimicrobial metabolites associated with pathogen suppression and plant growth promotion. The study highlights the potential of integrating biological and botanical inputs for effective stem rot management, reducing dependence on chemical fungicides and promoting environmentally safe, economically viable and sustainable mustard production systems.