GROWTH AND YIELD RESPONSE OF SOYBEAN UNDER DIFFERENT WEEDING REGIMES

Abstract

Studies were conducted during the 2011 cropping season at experimental field of the Faculty of Agriculture, University for Development studies in the Guinea Savanna agro ecological zone. The objectives of the study were to determine the effect of different weeding regimes on the growth and yield of soybean and also assess the economic feasibility of the weeding regimes. The experimental design was Randomized Complete Block Design (RCBD) with four replications. The treatments were five different weeding regimes which were no weeding, weeding at 3, 6 WAP, weeding at 3, 6, 9 WAP, weeding at 3, 6, 9, 12 WAP and weed free. Data collected included plant height, leaf area, stem girth, pod number and grain yield. Significant differences were observed among treatments on plant height, number of leaves per plant, stem girth, leaf area, number of days to 50% flowering, number of pods per plant and grain yield (kg/ha). The mean predominant weed floras at the experimental field were broad leaves (58.62%), sedges (26.93%) and grasses (14.44%). Weeding regime at 3, 6, 9, 12 WAP produced the highest grain yield of 1411 kg/ha. The economic analysis of the treatments also shows that farmers will be better off by adopting 3, 6, 9, 12 weeks after planting weeding regimes. Weeding at 3, 6, 9, 12 WAP is therefore recommended for high soybean yield and income.