Correlation and path analysis studies for morpho-physiological parameters in soybean (Glycine max (L.) Merrill)

Morpho-physiological traits, if correlated with grain yield in soybean, can be used as indirect selection for yield. The path coefficient analysis helps to partition correlation coefficient into direct and indirect effects and can be used to supplement information on correlation coefficients. Days to 50% flowering, days to maturity were found to have negative but highly significant correlation with seed yield under variable photoperiod. Number of pods per plant (60 DAS & 90 DAS) and oil content exhibited positive and significant correlation with seed yield. In path analysis, dry matter, Leaf area (60 DAS) and relative growth rate (RGR) had positive and direct effect towards seed yield. However, direct and indirect effects of yield attributing traits on seed yield from vegetative to harvesting phase are presented in Table 23. 100 seed weight (g) exhibited positive but lowest direct effect towards seed yield. Days to maturity, biological yield (kg/plot), plant height (30 DAS) and harvest index recorded high and positive direct effects while rest of the characters recorded negative direct effect towards seed yield.