Organic manures and biostimulants: A synergistic approach to boosting ashwagandha growth and yield

This study investigated the effects of organic manures and biostimulants on the growth and root yield of ashwagandha (Withania somnifera (L.) Dunal), a valuable medicinal herb widely used in Ayurvedic and Unani medicine. A field experiment was conducted at the Kerala Agricultural University, Vellanikkara from 2023 to 2024. The experiment followed a Factorial Randomized Block Design (FRBD) with 16 treatment combinations and three replications. The treatments included two factors: organic manures and biostimulants. Factor A consisted of four levels of organic manures: A1: FYM @ 5t/ha, A2: FYM @ 10 t/ha, A3: Vermicompost @ 2.5 t/ha, A4: Vermicompost @ 5 t/ha. Factor B included four levels of biostimulants: B1: Water spray (control), B2: Seaweed extract @ 0.4% at 1 and 3 MAP, B3: Humic and fulvic acid @ 0.4% @ 1 and 3 MAP, B4: Chitosan @ 0.1% at 1 and 3 MAP. Results demonstrated that vermicompost application at 5 t/ha resulted in significantly greater plant height (59.34 cm), biomass (141.35 g fresh and 53.98 g dry), and root development compared to other treatments. Seaweed extract as a biostimulant yielded the highest root growth and plant biomass, showing a 28.5% increase in root biomass. The findings indicate that organic farming significantly improves ashwagandha growth and yield, resulting in substantial export potential.