Appropriate Technology for Relay Intercropping: Cowpea Interplanted as Relay into Maize

Abstract

The risk of crop failure due to low, delayed or abrupt cessation of rainfall is a major constraint in both the uni and bi-modal rain fed cultures characteristic of West African agriculture. Relay intercropping offers a possible solution to the total crop failures encountered particularly by maize farmers. The study was undertaken to develop appropriate technologies for relay intercropping of cowpea into maize so that land use, resource management, and input utilization could be optimized. Residual moisture-use is of particular importance in this cropping situation. Four factors each at two levels evaluated for their effect on cowpea pod weight and grain yield. These were: maize variety component of relay (early and full season), bending-over of maize stalk below ear before interplanting cowpea (non-bending and bending over), time of interplanting cowpea into maize stand (hand weeding and chemical control). All the main factors except bending-over, significantly influenced cowpea yield. The results showed that light interception and residual moisture-use were critical to the yield of the relay cowpea. The results also indicated that though light was critical, the amount of light intercepted by interplanted cowpea did not change with bending-over. This labour demanding task can thus be avoided without any significant reduction in cowpea yield.