Grain yield is a complicated character which depends on many contributing traits. Little information is available related to the association of yield and its contributing traits in the comparison between F1 upland rice hybrids and their parental lines. Therefore, the study aimed to determine the associations among grain yield and its components as well as their direct and indirect effects on grain yield of F1 upland rice hybrids and their parental lines using path analysis. Evaluation of the analysis results revealed that the traits in F1 hybrids, i.e., grain weight per panicle (highest significant positive association and direct effect), panicle length, spikelet fertility, and flag leaf length (highly positive indirect effects on grain yield via grain weight per panicle), while the number of filled grains per panicle and flag leaf length in parental lines were the most influential traits because they had a positive association and highly positive direct effects on grain yield of upland rice. Thus the selection of these characters should improve the yield of upland rice varieties.
