Effect of plant spacing and weeding frequency on weed infestation, yield components and yield of mung bean [Vigna radiata (L.) Wilczek] at Kosokol, Bench Sheko zone, South Western Ethiopia

Abstract

Improper spacing and weed competition are one of the important production constraints that cause reduction in potential yield of mung bean. Therefore, an experiment was conducted at Bench Sheko Zone, South Western Ethiopia, during the 2019 main cropping season to evaluate the effect of plant spacing and frequency of weeding on weeds, yield components and yield of mung bean. There were 18 treatments comprising combination of three plant spacing (30 cm x 10 cm, 30 cm x 15 cm and 40 cm x 10 cm) and six weeding frequency [one hand weeding and hoeing at 2 weeks after crop emergence (WAE), one hand weeding and hoeing at 3 WAE, one hand weeding and hoeing at 4 WAE, two hand weeding and hoeing at 2 and 5 WAE, weed free check and weedy check]. The treatments were arranged in factorial combination in a randomized complete block design with three replications. Results showed the highest weed control efficiency obtained from interaction of 30cm x 10cm plant spacing and twice hand weeding and hoeing at 2 and 5 WAE. Significantly higher number of pods per plant (20.38) and seeds per pod (11.68) was obtained from weed free check. The highest grain yield 1412.9 kg ha-1and harvest index 42.94% were obtained from weed free check. However, the economic analysis revealed that the highest net benefit of 34965.2 ETB ha-1 were obtained from combined use of 30 cm × 10 cm plant spacing and twice hand weeding and hoeing at 2 and 5 WAE. Thus, it is suggested that planting Rasa variety of mung bean at 30 cm x 10 cm plant spacing and weeding the crop by hand-hoeing twice at two and five weeks after crop emergence resulted in optimum growth and grain yield of the crop at study area.