Agronomy of Indigenous Leafy Vegetables for Nutritional Security in South South Nigeria

This study examines the agronomy of indigenous leafy vegetables and develops improved production practices for enhancing their contribution to nutritional security in South South Nigeria. Indigenous vegetables including bitterleaf, waterleaf, African spinach, fluted pumpkin leaf, and Gnetum africanum are nutritionally superior to many exotic vegetables in micronutrient content and are culturally central to South South Nigerian cuisine, but their agronomic management is largely informal and productivity is below potential. This study evaluates improved agronomic practices for five priority indigenous vegetables across experimental sites in Rivers, Bayelsa, and Akwa Ibom States. Practice components evaluated include spacing, fertiliser type and rate, harvesting frequency, and water management. Nutritional composition including iron, zinc, beta-carotene, folate, and ascorbic acid are quantified in produce from improved and traditional management systems. Consumer and market assessment supplements the agronomic work. Findings reveal that improved management including optimised spacing, integrated organic-inorganic fertilisation, and frequent harvesting increases marketable leaf yield by 55 to 80 percent above traditional management across the five vegetables. Nutritional composition is maintained or enhanced under improved management, with bitterleaf showing the highest iron content at 28 milligrams per 100 grams dry weight. Market prices for consistently supplied, quality-graded indigenous vegetables are 28 percent higher than informally marketed equivalents. The study recommends standardised production packages for each indigenous vegetable and integration into state nutritional security extension programmes.

Keywords: indigenous vegetables, agronomy, nutritional security, South South Nigeria, leafy vegetables.