Abstract

This study was conducted during 2019-20 at Prince of Songkla University, Hat Yai campus, Thailand to calculate the correlation coefficient, path analysis, direct and indirect effects of ten popular upland rice genotypes (Oryza sativa) to determine the nature of relation between grain yield with other yield contributing traits. The experiment was designed as a completely randomized block design with three replications with observations on the growth, grain yield, and yield components of rice. The result showed that plant height, effective tiller, panicle length, panicle number, flag leaf length, flag leaf width, harvest index, filled grain, unfilled grain, seed fertility, seed length and seed width was positively significant and phenotypically correlated with grain yield per genotypes (0.657, 0.166, 0.589, 0.778, 0.136, 0.538, 0.228, 0.816, 0.081, 0.424, 0.168 and 0.106, respectively). Path analysis indicated that plant height, effective tiller, panicle length, panicle number, internode length and filled grain exhibited positive direct effect on grain yield. Among these traits, filled grain, seed fertility, seed width, panicle number and effective tiller possessed high positive direct effects (10.96, 7.50,1.25, 0.4802 and 0.1665). Thus, selection of these traits like effective tiller, panicle number, filled grain, seed fertility can bring improvement yield performance of upland rice.