Effect of Plant Spacing on Yield and Yield Related Traits of Common Bean (Phaseolus vulgaris L.) Varieties at Areka, Southern Ethiopia

The productivity of common bean is low due to use of inappropriate inter and intra row spacing for varieties with different seed sizes and growth habits in the study area. Thus, a field experiment was conducted at Areka, in the ‘meher' season of 2015 to assess the effects of inter and intra row spacing on yield and yield related traits of common bean varieties. The two common bean varieties [Hawassa dume (small seed sized) and Ibbado (large seed sized)], three inter (30 cm, 40 cm and 50 cm) and three intra (7 cm, 10 cm and 13 cm) row spacing were factorially combined in randomized complete block design with three replications. The result showed significantly (P<0.01) higher days to 50% flowering (45.7), days to 90% physiological maturity (78.3) and hundred seed weight (44.07 g) for variety Ibbado, while significantly (P<0.01) highest number of total nodules (29.64), effective nodules (14.93), pod per plant (19.5), primary branches (2.6) and grain yield (2264 kg ha-1) were recorded for variety Hawassa dume. As inter row increased from 30 cm to 50 cm; plant height, days to physiological maturity and grain yield decreased, while pods per plant and hundred seed weight increased. Also, as intra row increased from 7 cm to 13 cm; leaf area index, plant height, dry biomass and grain yield were decreased, whereas leaf area, pods per plant, seeds per pod and hundred seed weight were increased. Among the interaction combinations of variety Hawassa dume in 40 cm, 30 cm and 50 cm row spacing gave significant (P<0.01), highest leaf area (1099.9 cm2), leaf area index (3.41) and seeds per pod (5.24), respectively, while highest dry biomass (4137 kg ha-1) for variety Hawassa dume and (4533 kg ha-1) for variety Ibbado in 30 cm. From the results of this study it can preliminary be concluded that the 30 cm inter-row and 7 cm intra-row spacing can be used for both varieties (Hawassa dume and Ibbado) to improve the productivity of the crop under study area.