Sustainable Cowpea (Vigna unguiculata L.Walp) Production as Impacted by Integrated Weed Management Practices
Abstract
Field trials were conducted over two consecutive growing seasons at the Research and Teaching farm of the Faculty of Agriculture, Bayero University Kano (Latitude 11o 58 N, Longitude 8o 25 E; altitude 458 m als). The efficacy of twelve different weed control treatments using various herbicides alone, in combination, or in addition to hoe weeding was evaluated on cowpea (var. IT99K-573-1-1) in a randomized complete block design (RCBD) with three replications. The treatments comprised of weedy check (control), hoe weeding at 3 & 6 weeks after sowing (WAS), metolachlor at 2.0 kg a.i.ha-1, imazethapyr at 3.0 kg a.i.ha-1, pendimethalin at 2.0 kg a.i. ha-1, pendimethalin at 3.0 kg a.i. ha-1, pendimethalin 1.0 + imazethapyr 1.0 kg a.i.ha-1, metolachlor 1.5 + pendimethalin 1.5 kg a.i.ha-1, imazethapyr 1.0 + pendimethalin 1.0 kg a.i.ha-1 + SHW at 6 WAS, metolachlor 1.5 + pendimethalin 1.5 kg a.i.ha-1 + SHW at 6 WAS, metolachlor at 2.0 + SHW at 6 WAS, and pendimethalin at 2.0 + SHW at 6 WAS. Data were collected on cowpea growth, yield, and weed management parameters and were subjected to analysis of variance (ANOVA), and treatment means were compared using the Student Newman-Keuls test (SNK) at a 5% level of probability. Results indicated that weed control significantly (p < 0.001) influenced crop growth and yield. Herbicide treatments, particularly those involving pendimethalin, imazethapyr, and metolachlor, effectively suppressed weed growth, leading to increased plant height (101.9-147.9 cm), leaf area (44.87-47.93 cm2), and number of leaves (113.17-122.03). Additionally, these treatments resulted in a higher number of pods (74.47-77.10) and seed yields (702.0-705.5 kg ha⁻¹) compared to the weedy check. Findings further revealed that the combination of herbicides with hoe weeding proved to be the most effective strategy, providing superior weed control and maximizing crop productivity. These findings highlight the importance of integrated weed management practices for sustainable cowpea production.
