Jibril Temesgen, Taye Kufa and Zeleke Wondimu
Limited farmland size owned by smallholding farmer is one of the challenges to increase crop production and productivity at the study area in particular and in the country at large. Accordingly, famers have a long standing traditional knowledge of growing multiple crop types in different cropping patterns. Intercropping is one of the crop combination systems practiced by resource poor farmers to increase crop production per unit area of land per year and reduce the risks to food and cash sources. However, research information is scanty on ideal intercropping technology options for irrigated agriculture. Hence, this study was conducted at the Jimma Agricultural Research Center in 2013/2014 with the objectives to determine the optimum component population density that maximizes productivity under Jimma conditions, southwest Ethiopia. The experiment was conducted in factorial experiment arranged in a Randomized Complete Block Design of three replications. The treatment combinations included six component densities (100% * 17.7%, 100% * 26.7%, 100% * 53.3%, 75% * 17.7%, 75% * 26.7%, 75% * 53.3%) of hybrid maize and common bean, and two common bean varieties (Nasir and Local Asendabo) along with sole maize and common bean varieties. Data on, phenology, growth, yield and yield components of the two crops were recorded and statistically analyzed. The analysis of variance showed that the interaction effects of bean varieties and component population densities as well as the main effects were comparable on the phenology of maize and common beans, except the main effects of varieties indicated significant variation on days to 50% emergency of common bean. All yield and yield components showed significant effect due to common bean variety, component density and interaction effects on maize and common bean. In general maize 100% population density intercropped with 26.7% population density of Nasir common bean variety; and as an alternative: - Maize with 75% population density intercropped with 53.3% population density of both varieties of common beans make farmers benefited from the system.