Effect of Spacing on Growth and Grain Yield of Cowpea Varieties (Vigna Unguiculata) in Guinea Savanna Zone, Nigeria

Abstract

Purpose: Field experiment was conducted at the Biotechnology Advanced Research Centre Farm, Garki-Abuja during 2022 cropping season to evaluate the effect of spacing on growth and grain yield of cowpea varieties. The experimental plot was ploughed and harrowed after which lining out was carried out. There were 24 plots with three replications. Each replicate consisted of 8 plots. Each treatment was in a plot size of 2.0 m x 2.0 m (4.0 m2). The alley way between replicates plots was 1.0 m and within replicates was 1.0 m. The treatments consisted of four spacing, (65 x 20 cm, 75 x 20 cm, 85 x 20 cm and 95 x 20 cm) designated as S1, S2, S3, and S4 and two cowpea varieties (TVU 14346 and TVU 14788). The treatments were 4 x 2 factorial experiment and fitted into a Randomized Complete Block Design (RCBD), replicated three times and data were collected on plant height per plant, number of leaves per plant, number of pods, pod length, number of seeds per plant, 100 seed weight, seed weight and grain seed yield. The seeds were sourced from the International Institute of Tropical Agriculture IITA) Ibadan. Two seeds were planted at the depth of 4 cm and later thinned to one three weeks after planting. Methodology: The treatments were subjected to analysis of variance (ANOVA) using CROP STAT statistical package and significant means compared using Duncan Multiple Range Test (DMRT). Findings: Results obtained revealed that the growth parameters of the plants increased as the plant aged with the highest number of leaves obtained from TVU 14788 (40.20) variety. There was significant (p≤0.05) difference in the yield performance with the highest grain yield gotten from TVU 14788 (7.42 t/ha) and the plants spaced with S1 (8.79 t/ha) gave the highest mean grain yield while the least mean value was received from S4 (3.98 t/ha). Unique Contribution to Theory, Practice and Policy: From this study, it could be stated that for optimum yield performance TVU 14788 and S1 thrived better than other treatments evaluated and could be recommended for farmers within this ecological zone.