CORRELATION AND PATH COEFFICIENT ANALYSIS AMONG GRAIN YIELD AND YIELD-RELATED TRAITS OF SOYBEANS (Glycine max (L.) Merill) GENOTYPES

Understanding the direct and indirect relationships between grain yield and its component traits are essential for effective indirect selection in soybean breeding. This study evaluated 70 soybean genotypes for grain yield and 11 yield-related traits, and performed correlation and path coefficient analysis to partition the effects of component traits on yield. Grain yield showed significant positive genotypic correlations with plant height (rg = 0.42, p<0.01), pods per plant (rg = 0.38, p<0.01), 100-seed weight (rg = 0.29, p<0.05), and seeds per pod (rg = 0.24, p<0.05). Path coefficient analysis at the genotypic level revealed that pods per plant exerted the highest positive direct effect on grain yield (P = 0.46), followed by 100-seed weight (P = 0.31) and plant height (P = 0.22). Seeds per pod showed a moderate direct effect (P = 0.18), while days to 50% flowering exerted a negative direct effect (P = -0.24), indicating that early flowering contributes to higher yield. The residual effect (R = 0.31) indicated that traits not included in the model (e.g., stress tolerance, harvest index) also influence yield. The high direct effect of pods per plant suggests that selection for increased pod number would be the most effective strategy for indirect yield improvement in this population. A selection index based on pods per plant, 100-seed weight, and early flowering is recommended for improving grain yield in these soybean genotypes.