The Effect of Sowing Date on Yield, Yield Components and Oil Content of Three Spring Safflower Cultivars under Full Irrigation in Tabriz (Carthamus tinctorius L.)

To study the effects of sowing date on seed yield and oil yield, its components and oil content of three spring safflower varieties a factorial experiment based on randomized complete block design with three replications was conducted during spring 2010 at Agricultural Research Station, Agriculture Faculty Islamic Azad University, Tabriz branch, Iran. Treatments in this study consisted of four levels for sowing date (26April, 2 May, 8 May, and 14May) and three safflower varieties (Mex33, Isfahan, Goldasht). Analysis of variance showed that late planting (26April) reduced seed yield and oil yield, seed number per head, head number per plant, 1000-seed weight and oil content of seed. The highest seed yield was observed in the first planting date (2267 kg/ha) and the lowest seed yield at the forth sowing date (1124 kg/ha). The highest head number per plant was obtained at first planting date (13.44) and the lowest was at the forth sowing date (6.77).The highest seed number per head was obtained at first planting date (57.78) and the lowest at the forth sowing date (36). The highest 1000-seed weight at first planting date (37.78gr) and lowest 1000-seed weight at the forth sowing date (26.33gr). The highest oil yield was obtained from first planting date (782.60 kg/ha) and lowest from fourth sowing date (292 kg/ha). Also, effect of sowing date on oil percentages gets no significant.