Growth and Yield Response of Cowpea Leaf Vegetable (Vigna unguiculata) to Boron Application in Kogi State

Cowpea (Vigna unguiculata) is cultivated in North Central Nigeria both as a grain legume and as a leafy vegetable, providing an important source of dietary protein and income for rural farming households in Kogi State. Boron is an essential micronutrient that plays a critical role in cell wall formation, reproductive development, and carbohydrate metabolism in leguminous crops. Boron deficiency has been documented in many Nigerian soils, yet its implications for leafy vegetable yield of cowpea remain understudied in the region. This study investigates the response of cowpea leaf vegetable yield to foliar application of borax at four rates (0, 0.5, 1.0, and 1.5 g/litre) in Lokoja, Kogi State. A field experiment was set up in a completely randomized block design with three replications during the wet season. Data collected include plant height, leaf area index, fresh leaf yield per plant, and dry matter content. Analysis of variance was applied to the data. Results reveal that boron applied at 1.0 g/litre significantly increased fresh leaf yield and leaf area index over the control and other rates. The study recommends foliar borax application at 1.0 g/litre for optimizing cowpea leaf vegetable production in Kogi State. Keywords: cowpea, Vigna unguiculata, boron, leaf vegetable, Kogi State