Path coefficient analysis for yield of early maturing soybean

Fourteen soybean lines/varieties were evaluated at Suranaree University of Technology experimental Farm, NakhonRatchasima, Thailand, in 2006-2007 using a randomized complete block design with 3 replications. The objectives of the studywere to investigate the correlations among some characters of soybean and to verify direct and indirect effects which will beused for the selection for seed yield. Eight characters were evaluated for phenotypic- genotypic correlations and path coefficients.These were days to flowering, branches per plant, nodes per plant, pods per plant, seeds per plant 100 seedsweight, days from flowering to maturity and yield. Means for yield and its components were significantly different among allgenotypes for all characters. Significantly positive phenotypic correlation was observed between seed yield and days toflowering. Further-more, genotypic correlation showed that seed yield was positively correlated with all characters except100 seeds weight. Pods per plant gave the highest positive direct effect on seed yield, followed by branches per plant. Inaddition, the indirect effects of most characters were high through pods per plant. The results obtained from genotypiccorrelations and path analyses showed that the efficiency in the selection for seed yield in early maturing soybean shouldincrease through the selection of pods per plant