The investigation of limited irrigation effect on agronomic characteristics and yield of sunflower cultivars

In order to study the limited irrigation effect on agronomic characteristics and yield of four sunflower cultivars, a split plot experiment on the base of randomized complete block design in three replications was done during two years in agriculture research field of Kaboutar Abad, Isfahan. Experimental treatments were: irrigation as main factor including three levels of optimum irrigation, mean limitation of water and sever limitation of water (Irrigation after 60, 90 and 120 mm evaporation from evaporation pan, class A, respectively) and sunflower cultivars secondary factor including four cultivars (Master, Lakumka, Favorit and Berezanski). Compound analysis results showed that the limited irrigation effects were significant on all criteria such as plant height, head diameter, seed yield and oil yield (p<0.01). Total seed number in head had not been affected by this treatment. Yield components such as 1000-seed weight and the number of filed seed in head caused 26 and 40 percentage reduction of seed yield in 90 and 120mm evaporation respectively, as compared with control. According to the correlation between oil yield with seed yield and oil percentage 33 and 53 percentage reduction of oil yield were observed in 90 and 120 mm evaporation treatments, respectively. Cultivar effect was also significant in all criteria (p<0.01) except oil percentage. The most seed and oil yield in optimum irrigation and 90mm evaporation treatment was observed in Master cultivar but in irrigation after 120mm evaporation, was observed in Lakumka. also, Berezanski had the least seed and oil yield in three irrigation levels.