Abstract The compatibility analysis in intercropping is an important aspect while studying field crops to increase productivity per unit area. However, the lack of information on intercropping compatibility forces a user to employ the varieties developed only for sole cropping conditions. This study estimated the relative importance of general combining ability (GCA) and specific combining ability (SCA) in advanced inbred lines in sole and intercropping systems. Elite maize inbred line test crosses were evaluated at two locations under sole and intercropping conditions. The data for yield and yield related traits were collected and analyzed to quantify their effect across the locations and cropping system. The main effects of locations, genotypes, cropping systems, lines, and tester GCA mean squares were greater than the interaction effect, indicating that the genes controlling the traits were partially similar across the locations and cropping systems. The mean squares due to environments, cropping system, environment vs cropping system, lines GCA and tester GCA were significant for most of the studied traits. The GCA effects for grain yield under intercropping condition over the two location was not significant for most of the lines except for L18 (0.95**) but the two testers T1 (0.26*), T2 (-0.26*) showed significant GCA effect. Unlike the intercropping conditions most of the inbredlines showed significant combined GCA effects under sole cropping conditions. L2 and L18 showed highly significant GCA effects for most of the traits studied across locations and cropping system showing they are good combiners over location and cropping systems.

Keywords: combining ability, inbredlines, cropping system, maize.