بررسی تحمل کلزا به تنش های شوری، خشکی، سرما(تنش تاریخ کاشت)

In order to study the effect of three sowing date on some traits of two wniter rapeseed varieties, an experiment was conducted at the agricultural research station, urmieh university in 1377-78. A split plot design with four replications was used in R C B design. Two winter rapeseed varieies as a main factor (Ceres, Telayeh) and three planting date (25 shahrivar, 5 and 10 mehr) as a subfactor were carried out. There was a significant difference (1%) between all of the studied traites. late sowing decrease the total dry weight. pods in shrub, 1000 K.W. and oil percentage. both varieties showed significant differences between the date of sowing and variety of pods n shrub, total dry weight, plant height and K.W. in shrub, but for other traits there was non significant differences. in this study it was found that late sowing date extremely decreases the oil percentage and seed yield, because of high susceptibility of this plant for environmental factors and its genotype. as a general result (20-30 shahrivar) is a favorable sowing date in urmieh telayeh variety is recommend because of its high yield and high oil percentage.