Evaluation of Organic Manures and Recommended Chemical Fertilizers on Growth, Yield, and Economic Performance of Okra (Abelmoschus esculentus L.) Under Irrigated Condition
Okra is an economically important vegetable crop with high nutritional value, widely cultivated in tropical and subtropical regions globally. An experiment was conducted to assess the effect of eight treatments on the growth, yield, and economic performance of okra (Abelmoschus esculentus (L.) Moench) under irrigated conditions in the Kilinochchi District, Sri Lanka, during September to November 2023. The experiment was conducted in a Randomized Complete Block Design (RCBD) with three replicates. Eight treatments (T1–T8) consisting of different organic manure applications, and the Department of Agriculture (DOA)-recommended chemical fertilizers were applied, including a control treatment without organic manure. Haritha okra was used as the test variety. Growth parameters including plant height, dry weight, and number of leaves, and yield parameters including number of pods per plant, fresh pod weight, and shelf life were evaluated. Poultry manure applied at 460 g plant⁻¹ (T2) recorded the highest plant height (31.4 cm), number of leaves (8.0 leaves plant⁻¹), dry pod weight (13.3 g plant⁻¹), fresh pod weight (130 g plant⁻¹), number of pods per plant (8 pods), and shelf life (5.7 days). Compared with the control treatment (T1), poultry manure increased plant height by 35.3%, fresh pod weight by 160%, and shelf life by 32.6%. No significant difference (p ≤ 0.05) was observed between T2 and T5 (cattle manure: poultry manure, 230 g: 230 g plant⁻¹). The highest benefit-cost ratio was recorded in T2 and T5. It can be concluded that poultry manure at 460 g plant⁻¹ was the most effective treatment for improving the growth, yield, and economic performance of okra under irrigated conditions.