Dose-Dependent Interaction Between Moringa Leaf Extract and NPK Fertilization on Vegetative Growth and Reproductive Biomass of Common Bean (Phaseolus vulgaris L.)

Integration of bio stimulants with mineral fertilization has gained increasing attention as a sustainable strategy to enhance crop productivity. Moringa leaf extract (MLE) is recognized for its bioactive compounds that may improve plant growth and yield however, its effectiveness largely depends on nutrient availability. This study aimed to evaluate the interaction between MLE concentration and NPK fertilizer rate on the growth and production of common bean, particularly pod weight per plant. The experiment was arranged in a factorial design with four MLE concentrations (0, 5, 7.5, and 15%) and three NPK rates (350, 450, and 550 kg ha⁻¹). Data were analyzed using analysis of variance followed by the Honestly Significant Difference (HSD) test at 5%. The results revealed a significant interaction between MLE concentration and NPK rate on pod weight per plant. The highest pod weight (324.48 g per plant) was obtained with the combination of 15% MLE and 450 kg ha⁻¹ NPK. Increasing the NPK rate to 550 kg ha⁻¹ did not further enhance yield and, in some treatments, reduced the positive effect of MLE. Application is most effective when integrated with balanced mineral fertilization. The combination of 7.5-15% MLE and 450 kg ha⁻¹ NPK is recommended to optimize reproductive biomass in common bean. These findings contribute to the development of more efficient and sustainable fertilization strategies in agriculture.