مطالعه تاثیر تاریخ کاشت بر کارایی مصرف آب در ارقام بهاره گلرنگ

 In order to investigate the effect of sowing date on water use efficiency in spring safflower cultivars, An experiment was conducted at the research farm of faculty of Agriculture, Zanjan University at 2013. This study was designed as factorial experiment based on randomized complete block design with four replications. First factor, spring safflower cultivars, includes Goldasht, zenderod and sina and second factor (sowing date) included two dates (20 March and 20 April). In this study some traits included, plant height, number of head per plant, number of seeds per head, seed weight, seed yield, biological yield, water use efficiency and harvest index were measured. Results showed that water use efficiency in two sowing date had significant different. Also comparisons of means showed that water use efficiency on first date (2.237 kg/m3) significantly higher than second date (2.077 kg/m3). The results of analysis of variance show that planting dates had not significant effect on seed yield. But cultivars had significant different in yield. Between cultivars zenderod with 2150.7 kg/ ha seed yield showed the highest seed yield and Goldasht cultivar with 1893.44 kg/ha had the lowest seed yield.