Response of yield and yield components of soybean (Glycin max L.) cultivars to sowing dates under Sari conditions

In order to investigate the effect of sowing date on yield and yield components of soybean, an experiment was carried out at split-plot in a randomized complete block design with four replications under Sari region in 2009-2010. The main plot was sowing dates including on 5th June, 20th June and 5th July and sub plot was three cultivars including JK, 033 and Telar. Results showed the most of pod weight per plant, pod number per m2, stem weight per hectare, grain yield per hectare, straw yield per hectare and biological yield per plant were obtained on 20th June. Small pods were observed in 5th June and the lowest pod weight per plant, pod number per m2, straw yield per hectare and biological yield per plant were obtained on 5th July. Telar cultivar had been the most grain yield per hectare and biological yield per plant, but highest pod height were the most in JK cultivar. The maximum of pod weight per plant, stem weight per hectare, grain yield per hectare, straw yield per hectare and biological yield per plant were observed at the interaction of planting date on 20th June and JK cultivar. Becuase of the fact that yield and yield comonents increased in 20th june, this treatment was the best sowaing date.