Effect of Intra-Row Spacing on Haricot Bean (Phaseolus vulgaris L.) Production in humid Tropics of Southern Ethiopia.

Field experiment was conducted at the research farm of Dilla University in 2015 main cropping season, with the objective of determining the optimum plant spacing for better productivity of haricot bean under the humid conditions of Dilla, southern Ethiopia. A well-adapted haricot bean variety namely, Hawassa-Dume, was tested at 5, 10, 15 and 20 cm intra-row spacing with 40 cm inter-row spacing for each treatment. The analysis of variance (ANOVA) revealed that plant height, number of branch plant-1, pod plant-1, total biomass and grain yield were significantly (p < 0.05) influenced by varying intra-row spacing. In contrary, number of leaves plant-1, seed pod-1 and thousand seed weight were insignificant in all intra-row spacing. Increasing the intra-row spacing beyond 10 cm resulted in significant reduction in grain and biomass yields, but consistent increase in number of branches plant-1 and pod plant-1. Compared with the grain yield obtained at widest intra-row spacing (20 cm), increase in the grain yield was recorded at 5 cm and 10 cm intra-row spacing that were 22.9% and 33.2%, respectively. In general, the result suggests that narrow intra-row spacing at 10 cm which corresponds to plant population density of 266,667 plants ha-1 was better for achieving optimum grain yield under humid environment. To confirm this, similar investigations should repeated in multi- locations and years. Keywords: Yield, yield components, Haricot bean, Intra-row spacin