Assessing Integrated Nutrient Management Strategies for Improved Growth Rates and Nutrient Uptake in Stevia (Stevia rebaudiana Bertoni)

Abstract

With the increasing demand for stevia as a natural sweetener among health-conscious diabetics, a field trial was conducted in 2022 and 2023 at the Agronomy farm, College of Agriculture, Vellanikkara, to evaluate the impact of integrated nutrient management (INM) on growth rates and nutrient uptake of stevia (Stevia rebaudiana Bertoni). The experiment followed a factorial randomized block design (FRBD) with two factors: manure (no manure, vermicompost at 2.5 t ha-¹, and farmyard manure at 5 t ha-¹) and NPK levels (20:10:10, 40:20:20, and 60:30:30 kg ha-¹). The highest crop growth rate (CGR) was observed with FYM @ 5 t ha-¹ and 60:30:30 NPK kg ha-¹, particularly at the 30-45 DAP stage. Relative growth rate (RGR) was significantly influenced only during the first growth period, with the highest RGR observed under FYM @ 5 t ha-¹ and 60:30:30 NPK kg ha-¹. Pooled mean nitrogen and phosphorus uptake was highest with FYM @ 5 t ha-¹, and higher potassium uptake was with FYM @ 5 t ha-¹ and vermicompost @ 2.5 t ha-¹ among manures The highest NPK uptake was obtained with 60:30:30 NPK kg ha⁻¹ among NPK levels. In conclusion, the combined application of FYM @ 5 t ha-¹ and NPK @ 60:30:30 kg ha-¹ resulted in better growth performance and nutrient absorption by stevia.