Effect of Harvesting Stage on Cowpea Leaf Nutrient Composition

Abstract

Abstract: Cowpea leaves are enjoyed as vegetables in many parts of Africa as they contain a lot of antioxidants, micronutrients and nutraceuticals whose deficiency is prevalent among people in Sub-Saharan Africa. Cowpea leaves undergo several physiological and metabolic changes during their maturity stages which may affect their nutritional content. However, farmers lack knowledge on the best cowpea harvesting stage. This research therefore aimed at obtaining information on the right harvesting stage that would enhance cowpea utilization by farmers. Cowpeas variety M66 was planted in RCBD and the treatments which were replicated thrice included harvesting at 21, 35 and 49 DAS. Data was collected on chlorophyll content, iron, calcium, crude fibre, beta carotene, protein and moisture content. The data was subjected for variance using Statistical Analysis System 9.2 edition and significantly different means separated using LSD at 5%. The harvesting stage significantly (p ≤ 0.05) influenced the chlorophyll content with 49 DAS recording the highest content at 51.39 nm followed by 35 DAS with 41.87 nm and the least at 21 DAS with 22. 05 nm. The moisture content decreased with the stage of harvest with highest moisture content being observed at 21 DAS and the least at 49 DAS in both trials. The iron content of cowpea leaves was significantly (p ≤ 0.05) different at 49 DAS in both trials. The calcium content at 21 and 49 DAS in both trials was significantly (p ≤ 0.05) different. The protein content was significant (p ≤ 0.05) in all the stages of harvesting with the highest protein content in both trials being recorded at 21 DAS and the least being recorded at 49 DAS in both. Crude fibre content increased with the stage of harvesting in both trials. This research highlights the essence of harvesting cowpea leaves at the correct harvest stage for increased nutrient utilization.