Evaluation of agronomical and phonological traits of soybean cultivars at different management systems in Gorgan region

The aim of this study was investigation of phonological relationship with some yield and yields component traits at different management systems in two soybean cultivars namely Gorgan 3 and Katul in Gorgan region. Therefore, 16 and 18 fields of Gorgan 3 and Katul were selected, respectively. Consequently, in each field the phonological and yield related parameters were evaluated. Generally, regression relationship showed that in each cultivar, the regression relationship of phonological stages with number of pod per plant, number of grain per meter square, shoot dry mater and grain yield was significant. However, the regression relationship between the number of days from sowing to physiological maturing with shoot dry matter in Gorgan 3 (R2= %70**) and Katul (R2= %62**) was positive and significant. Moreover, the regression relationship between days from sowing to flower initialization and days from sowing to physiological maturing with grain yield was significant in each cultivar. Meanwhile, this relation in Gorgan 3 was second best linear regression (R2= %71** and R2= %80**, respectively) and in Katul was a simple linear one (R2= 69** and R2= %51*, respectively). Also, the regression relationship between shoot dry matter and grain yield in each cultivar was logarithmic and significant (P>0.01). This logarithmic relationship was demonstrated 53 and 67 percent of variation in Gorgan 3 and Katul cultivars, respectively. The results of this experiment showed that with understanding of phonological and agronomical traits relationships in soybean growth cycle under field condition and with time scaling of growth stages, the yield can be increased.