بررسی اثر تاریخهای مختلف کاشت و میزان بذر مصرفی بر عملکرد دانه دو رقم گندم نان

n order to evaluation of planting dates and densities effects on seed yield of bread wheat, an experiment was conducted based on randomized complete block design with arrangement of split-split design with three replications during 2012-13 at Qarakheil Agronomical Research Station, located in Mazandaran. The main plots were included three planting dates ( Nov. 11, Nov. 26 and Dec. 11) and sub plots were also included two lines of bread wheat (N-80-19 , Darya) and sub-sub plots were contained three plant densities including 350, 425 and 500 seeds per square meters. The results indicated that planting dates had significant effects on grain yield, spike weight, grain weight in spike, number of spikes per square meters and number of grains per spike at 0.01 probability level and also had significant effect on plant height at 0.05 probability level, so that the highest grain yield (4719 kg/ha) was achieved for the first planting date (Nov. 11). In this study the variety had significant effects on grain yield, number of spikes per square meters and 1000-grain at 0.01 probability level and also had significant effect on number of grains per spike at 0.05 probability level and Darya variety with 4440 kg/ha had highest seed yield. Plant density had significant effect on number of spikes per square meter and also had significant effects on number of spikes per square meters at 0.05 probability level and 350 seeds per square meters with 4285 kg/ha had highest grain yield.