PATH COEFFICIENT AND CORRELATION ANALYSIS IN SECOND CROP SOYBEAN [Glycine max (L.) Merrill]

Abstract

Soybean is the most widely grown leguminous and nutritionally important crop in the world. The selection criteria in soybean breeding suitable for second crop (double cropping) are expected to vary according to the main product conditions. Fourteen soybean [Glycine max (L.) Merr.] genotypes were studied in 2014, 2015 and 2016 to determine selection criteria for plant breeders using correlation and path coefficient analyses in soybean under second crop conditions. Randomized complete block design with four replicates was used for laying out the field experiments at research fields of Ege University. Variance analysis was perform for each characters and it was concluded that the genotype x year interaction was statistically significant at the 1% probability level in terms of all the traits examined. According to results of the correlation analysis, it is seen that six traits are positively correlated with grain yield, while the other traits are negatively correlated with seed yield. The six characters are pod numbers per plant (r= 313.3*), days to 50% flowering (r= 0.270*), days to maturity (r=0.286*), plant height (r=0.027ns), first pod height (r=0.181ns) and crude protein ratio (r=0.112ns). Path coefficient analysis showed grain yield positively and directly effected by pods number per plant (0.5532) followed by day to maturity (0.2483), plant height (0.1920), crude protein ratio (0.0403), first pod height (0.0266) and days to 50% flowering (0.0104); Grain yield was negatively and directly effected by 100-seed weight (-0.1697) and crude oil ratio (-0.0097). In conclusion under the second crop conditions, pod number per plant could be used as a selection criterion due to its high direct and positively effect on grain yield.