This experiment was conducted at the Agricultural Research Farm of Isfahan University of Technology in 2007-2008 to evaluate the effects of seed treatment and the level of soil moisture on three safflower cultivars. A split plot factorial arrangement was used in a randomized complete block design with three replications. Main-plot consisted of three irrigation regimes (60, 105 and 140 mm cumulative evaporation from Class A pan) and sub-plot consisted of two seed treatments (control and hydropriming) and three safflower cultivars (Kuseh, PI and IL111) which had been performed in the form of factorial experiment. Hydropriming for six hours was the best among the other priming, selected, and applied on three cultivars. The duration from planting to button formation, 50% flowering and 100% flowering stage were significantly shorter in hydropriming than in control. The duration from planting to all growth stages was higher in Kuseh compared to IL111 and PI cultivars. The level of soil moisture did not affected the duration of any growth stages. Plant hight, leaf area index, plant dry matter, number of buttons per plant, number of grains per button, grain weight and harvest index were higher in hydropriming compared to control. Plant hight, plant dry matter, number of buttons per plant, number of grains per button, grain weight and harvest index were reduced as the level of soil moisture was decreased. Leaf area index and plant dry matter were not significantly affected by the level of soil moisture at 50% flowering stage. Regardless of the level of soil moisture and cultivar, the grain yield was 35% more in hydropriming than control. The grain yield was more at higher level of soil moisture and in Kuseh than in IL111 and PI. The oil percentage and oil yield was higher in hydropriming compared to control and in Kuseh than in IL111 and PI. The oil percentage was significantly affected by the level of soil moisture. However, the oil percentage decreased as the level of soil moisture was reduced while; the protein percentage was increased as the level of soil moisture was reduced. The highest amount (1068/5 kg.ha -1 ) of oil yield and the highest amount (1010/3 kg.ha -1 ) of protein yield were obtained from Kuseh in hydropriming and the lowest amount (305/4 kg.ha -1 ) of oil yield and the lowest amount (500/4 kg.ha -1 ) of protein yield were achieved from PI in control. The results from this experiment show that to obtain the optimum yield from spring planting in areas with similar condition of this study the seed hydropiming compared to the seed control and Kuseh compared to IL111 and PI cultivars seems to be superior
