Agronomic Performance of Four Cowpea (Vigna unguiculata L. Walp) Varieties under Different Inter-row Spacings in Buea, Cameroon

Abstract

Aims: Two field trials were conducted to investigate the effect of inter-row spacing on the growth and yield of cowpea. Study Design: The first trial was set up as a randomized complete block design with three replications. The second trial was set up as a split-plot arrangement in a randomized complete block design and the treatments were replicated three times. Place and Duration of Study: The trials were conducted at the Teaching and Research Farm of the University of Buea in 2014 and 2016-2017. Methodology: In the first trial, the variety VYA was grown at three inter-row spacings (45, 75 and 90 cm). The second trial comprised three inter-row spacings (45, 60 and 75 cm) and four varieties (RIL 69, RIL 79, RIL 265 and VYA). In both trials, the intra-row spacing was 25 cm. Results: Inter-row spacing significantly influenced (P<0.05) the performance of cowpea. In 2014, cowpea on rows spaced 75 and 90 cm apart produced more leaves and fodder yield than that spaced 45 cm apart. In both trials, cowpea on rows spaced 60, 75 and 90 cm apart produced taller plants with larger stems than that on rows spaced 45 cm apart. However, grain yield increased with a decrease in inter-row spacing for all varieties; the highest yield (6.04 tons-1) was recorded for RIL 69 on rows spaced 45 cm apart. Among the varieties, RIL 69 had the highest fodder yield (4.7 tons-1). Conclusion: The results of this study indicate that cowpea should be sown in rows spaced 45 cm apart, for optimum grain yield production in Buea.