Sweet flag (Acorus calamus L.), known for its pesticidal and seed-quality–enhancing properties due to its essential oil richness. The study quantified sweet flag rhizome compounds and assessed their effectiveness in improving field bean (var. HA-5) under field and lab conditions. Essential oil was extracted by hydro-distillation and quantified using gas chromatography. A foliar spray experiment was conducted using a randomized complete block design to assess the effects of sweet flag rhizome powder, rhizome oil, and a chemical check on crop growth, pest and disease incidence. A nine-month storage study was conducted under laboratory conditions to evaluate seed storability. The essential oil yield aveaged 0.29 % and was dominated by β-asarone. Results indicated that moderate concentrations of sweet flag rhizome powder and oil significantly improved seed emergence, plant growth, and plant stand, while also reducing pest and disease incidence. Seed treatment with rhizome powder at 10 g/kg consistently maintained higher seed quality during storage. Sweet flag rhizome–based treatments demonstrated strong potential as eco-friendly options for enhancing field performance and seed storability.