Microbiology Research Journal International

Sclerotinia stem rot is an important constraint on the productivity of Indian mustard (Brassica juncea L.), and effective management requires approaches that are both agronomically effective and economically feasible. A field experiment was conducted during the rabi seasons of 2023–24 and 2024–25 at the Central Research Farm, Department of Plant Pathology, NAI, SHUATS, Prayagraj, Uttar Pradesh, to evaluate chemical fungicides, biological agents and their integrated treatments for improving seed yield and economic returns of mustard. Fourteen treatments, including an untreated control, were evaluated under natural field conditions. Seed yield, percentage increase in yield over the control and cost–benefit (C:B) ratio were recorded, and data were subjected to statistical analysis for individual years and pooled over the two seasons. Among the treatments, propiconazole (T₂) applied as seed treatment at 0.1% followed by foliar application at 0.1% at 30 and 50% bloom stages consistently produced the highest seed yield, recording 15.89 and 15.52 q ha⁻¹ during 2023–24 and 2024–25, respectively, compared with 11.59 and 11.00 q ha⁻¹ in the untreated control. The pooled seed yield under T₂ was 15.70 q ha⁻¹, representing a 38.24% increase over the control, with the highest pooled C:B ratio of 1.99. Carbendazim (T₁) and thiophanate methyl (T₃) ranked next, with pooled yields of 15.52 and 15.13 q ha⁻¹ and C:B ratios of 1.97 and 1.92, respectively. Among the biological and integrated treatments, T₈, comprising Trichoderma harzianum seed and soil application followed by Pseudomonas fluorescens foliar application at 30 and 50% bloom stages, recorded the highest pooled seed yield (14.65 q ha⁻¹) and yield increase (29.41%), with a C:B ratio of 1.83. The findings demonstrated that propiconazole was the most effective treatment for maximising mustard seed yield and economic returns under the prevailing conditions of Prayagraj. However, the comparatively strong performance of the T. harzianum–P. fluorescens combination highlights its potential as a biological component of integrated disease management for more sustainable mustard production.