NITROGEN SOURCE AND APPLICATION RATE REGULATE GROWTH DYNAMICS AND YIELD FORMATION IN COMMON BEAN (PHASEOLUS VULGARIS L.)

Common bean (Phaseolus vulgaris L.) is an important legume crop widely cultivated for its nutritional and economic value.Adequate nitrogen fertilization is essential for supporting vegetative growth and improving yield performance in bean cultivation systems.This study evaluated the effects of nitrogen fertilizer source and application rate on the growth and yield of common bean under field conditions.The experiment was arranged using a Randomized Block Design with three replications.Two nitrogen fertilizer sources were tested: urea and ammonium sulfate.Each fertilizer source was applied at five nitrogen rates: 60, 80, 100, 120, and 140 kg N ha⁻¹, resulting in ten treatment combinations.Observed variables included plant height, number of leaves, number of branches, leaf area, number of flowers, number of pods per plant, pod length, pod diameter, fresh pod weight per plant, and dry weight of 100 seeds.Data were analyzed using analysis of variance followed by a Least Significant Difference test at the 5% significance level.Nitrogen fertilization significantly affected several growth and yield parameters of common bean.The treatment receiving urea at 100 kg N ha⁻¹ consistently produced the highest values for plant height, leaf number, flower formation, pod number, and fresh pod weight.In contrast, leaf area, pod length, and pod diameter were not significantly influenced by nitrogen treatments.Overall, urea fertilizer provided slightly better growth and yield performance compared with ammonium sulfate at equivalent nitrogen doses.These findings indicate that nitrogen source and dosage play important roles in determining the productivity of common bean.Applying urea at 100 kg N ha⁻¹ is recommended to achieve optimal growth and yield under similar cultivation conditions.