Effectiveness of cowpea (Vigna unguiculata L.) living mulch on weed suppression and yield of maize (Zea mays L.)

Abstract

Abstract Weed control plays a vital role in achieving higher maize yield. We tested the hypothesis that interseeding cowpea as living mulch with maize will reduce biomass and diversity of weeds, and improve soil physical properties and maize yield. In 2017/2018 cropping seasons, a 2 × 4 factorial experiment was laid in a randomized complete block design with three replications at the Savelugu Municipality of Northern Ghana. The factorial treatment consisted of three cowpea varieties interseeded with two maize genotypes and a control (maize with no living mulch). Our result showed that, in both seasons, weed biomass and diversity, soil temperature, and grain yield were significantly (p < 0.05) higher in control plots than in cowpea living mulch plots at all growth stages of both maize varieties. However, maize growth was not affected by weeds at tasseling. We established that cowpea varieties as living mulch in maize cropping have similar effect on soil moisture and temperature but have varying degrees of suppressing weeds and improving maize yield. The cowpea living mulch had weed biomass of 0.5 t ha−1 compared to 2.6 t ha−1 in the control. In addition, living mulch plots had maize grain of 2 t ha−1 and stover yield of 3 t ha−1 compared to 0.98 and 2 t ha−1 respectively in the control. In conclusion, choosing the appropriate time for intercropping living mulches and selection of plant species (growth and canopy cover) for living mulch are essential in suppressing growth of weeds.