Interrelationships of agronomical characteristics in soybean (Glycine max) grown in different environments

Abstract

This study was conducted to determine the correlations between seed yield and certain yield components and direct and indirect effects of these characters on seed yield in soybean [Glycine max (L.) Merrill]. Eight cultivars were evaluated in two locations (Mustafakemalpasa & Gorukle) of Southern Marmara region, Turkey during two years (2000 & 2001) to determine correlations and path coefficients. Certain agronomical traits such as plant height, first pod height, number of pods per plant, number of seeds per plant, number of seeds per pod, 1000 seed weight and seed yield. Combined data over the years and locations indicated that seed yield had significant correlations with number of pods per plant (r = 0.458; P<0.01), number of seeds per plant (r = 0.329; P<0.01) and number of seeds per pod (r = 0.491; P<0.01). Positive associations only between seed yield and number of pods per plant were stable over the years and locations. Path coefficient analysis indicated that the number of seeds per pod gave the greatest direct positive effect (0.4728) on seed yield, followed by number of pods per plant (0.3988). Direct effects on seed yield were 57.0% and 50.4% for number of seeds per pod and number of pods per plant, respectively. Direct positive effect of number of pods per plant were seen stable over the years and locations. As a result, the number of seeds per pod and the number of pods per plant could be used as a selection criterion in breeding, because they were the most important factors in determining seed yield.