Correlation and Path Coefficient Analyses of Grain Yield and Yield Components in Two-Rowed of Barley (Hordeum vulgare convar. distichon) Varieties
This research sought to determine the correlations between grain yield and yield components and to measure the direct and indirect effects of yield components on grain yield in barley by using correlation coefficient and path analysis methods, respectively. This research was conducted with ten varieties of two-rowed barley under the ecological conditions of the coastal zone of northwest Turkey during the years 2003-2004. Agronomic traits such as grain yield, plant height, spike length, kernel number per spike, kernel weight per spike, spike number per m2, harvest index and 1000-kernel weight were determined. The data from two years were combined. Correlation analyses indicated that the grain yield was positively and significantly associated with all the yield components except 1000-kernel weight. The highest correlation coefficients were found between grain yield and kernel number per spike (r = +0.406), and between grain yield and harvest index (r = +0.474). Results of path analyses indicated that harvest index had the greatest direct effect (+0.7716) on grain yield followed by spike number per m2 (+0.3359) and kernel number per spike (+0.2081). Percentages of their direct effect were 71.97%, 48.47% and 28.22%, respectively. On the other hand, most of the indirect effects of yield components on grain yield were found to be significant and positive. Because of the significant effects of the harvest index, spike number per m2 and kernel number per spike on grain yield, they may be regarded as criteria for barley improvement and breeding programs.