Correlation and "path" coefficient analysis for yield and yield components in winter barley

Abstract

In order to determine in the most precise manner possible the cause-and-effect relations between direct and indirect grain yield components in winter barley, the simple correlation method was applied and path coefficient analysis was used. Correlations between grain yield, harvest index, stem height, grain number and weight per spike and biological yield, taking grain yield as a dependent variable, and the other traits as the independent ones, were studied. The highest positive correlation (0.85) was obtained between biological yield and grain yield and it resulted from both the high direct effect of biological yield on grain yield (0.58) and high indirect effects exerted via all the traits investigated. The grain number per spike was also found to be positively correlated with the yield. 

High positive correlation was established between the harvest index and the grain yield by both the simple coefficient (0.68) and the partial path coefficient methods (0.38). Direct effect of the stem height on yield was registered to be far smaller than it could have been concluded only on the basis of the correlation coefficients, because the stem height indirectly affected the yield via biological yield, and to a lesser degree via the harvest index and the grain number. No significant correlation between the grain weight per spike and yield was determined.