Bioproductivity and grain quality of two cowpea varieties in relation to frequency of hand weeding

Abstract

The concern for human health and safety coupled with the increase in herbicides resistant weeds necessitated the need to investigate the effect of frequency of hand weeding on weed suppression, productivity and grains quality in two varieties of cowpea (Tvx 3236 and Ife brown). Plot layout was a split-plot arrangement in complete randomized block design with three replications. The cowpea lines were subjected to five treatments of frequency of hand weeding. Data on weed and crop were subjected to Analysis of Variance. Means were separated using Duncan Multiple Range Test at 0.05 level of significance. Weed species that were found to be preponderant include Brachiaria deflexa, Euphorbia heterophylla and Commelina benghalensis. The three hand weeding at 3, 6 and 9 weeks after planting (WAP) showed the highest weed control efficiency of 90.48 % followed by those of two hand weeding at 3 and 6 WAP (86.98%) and one hand weeding at 3 WAP (74.68%). The weed free check was the most effective in controlling weeds (93.80%). Growth and productivity of the two cowpea lines were enhanced with increase in frequency of hand weeding when compared with the weedy check. Weeds reduced crop yield by 56.17%. The results of grain quality such as crude protein, lipid content, ash and crude fibre were also enhanced with increase in frequency of hand weeding. Generally, growth and yield were higher in Ife brown than Tvx3236. The research was limited to one cropping season and there is need for reproducibility for consistent of results. The study concluded that weeding twice and three times were found to be feasible since these frequencies of weeding times promoted effective weed reduction, higher growth, and yield and grain quality of the two cowpea varieties studied.

Keywords: growth and yield, proximate composition, three hand weeding, cowpea productivity