Weeding Frequency Effects on Growth and Yield of Dry Bean Intercropped with Sweet Sorghum and Cowpea under a Dryland Area

A better understanding of the dry bean ( Phaseolus vulgaris L.) growth and yield response to weed competition under the intercropping system is critical for improving sustainable weed management strategies. A two-year trial was conducted with three types of crop arrangement (sole cropping, inter-row, and intra-row intercropping) combined with weeding frequency (no weeding, weeding over the first 50 days of crop growth, and weed-free). Effects of the treatments were tested on dry bean agronomic indicators in terms of the following: 100-grain weight, dry biomass, grain yield, grains per pod, pods per plant, plant height, number of leaves per plant, and chlorophyll content. The intercropping pattern significantly affected dry bean pods per plant, height, and chlorophyll content, while weeding frequency significantly affected all measured agronomic indicators for dry bean, except for chlorophyll content, during the 2017/18 growing season. The results showed that the significant measured agronomic indicators were the lowest under no weed control; however, they increased as weeding frequency increased. The 2018/19 growing season followed a similar trend; however, the interaction effect significantly affected dry bean 100-grain weight, dry biomass, and number of leaves per plant at 40 days after emergence. The dry bean/sweet sorghum or cowpea intra-row intercropping and intermediate weeding frequency displayed optimum productivity.