Enhancing growth, yield, essential oil content, and composition of holy basil (Ocimum tenuiflorum L.) using red algae-based bio-stimulant under acidic conditions of the Western Himalayas

Abstract

Abstract Background The rising costs of synthetic fertilizers highlight the need for eco-friendly alternatives to enhance essential oil production in aromatic plants. This study evaluated the effects of red algae seaweed extract [Solieria chordalis (C. Agardh) J. Agardh] on holy basil (Ocimum tenuiflorum L.) in the Western Himalayas, by using five concentrations (0.0, 2.5, 5.0, 7.5, and 10.0 mL/L) and two application methods (drenching and foliar spray) in a factorial randomized block design analysing data at 5% significance level. Seaweed extract significantly improved growth and yield, with the highest essential oil content and biomass. By examining various concentrations and application techniques, the study seeks to determine the best practices for maximizing essential oil production. Results Application of S. chordalis at 7.5 mL/L, increased essential oil content by 71.4% and biomass by 63.4% compared to the control. The foliar application also resulted in 50% higher essential oil content than drenching. Application of S. chordalis at 7.5 mL/L significantly enhanced essential oil components like eugenol, methyl eugenol, and methyl cinnamate by 61.5%, 17.6% and, 48.4%, respectively, compared to control. Based on the results of the present study, the foliar application of 7.5 mL/L seaweed extract is recommended for optimizing holy basil growth, biomass yield, essential oil content and composition. Conclusions Based on the results of the present study, the foliar application of 7.5 mL/L seaweed extract is recommended for optimizing holy basil growth, biomass yield, essential oil content and composition. This study encourages the utilization of bio-stimulants, enhancing sustainability, and resilience in agriculture.

Keywords

• Tulsi
• Drenching
• Solieria chordalis
• Essential oil
• Seaweed
• Trichome density