Investigating of water deficit stress effect on yield and fatty acids of sunflower hybrids seed oil

The effect of water deficit stress has been evaluated on oil quality and yield of 11 sunflower hybrids in Karaj during 2012 and 2013. Three separate experiments have been carried out as the base of randomized complete block design with three replications to apply water deficit stress treatments. Irrigation of control, mild, and severe stress treatments are performed on the base of 60, 120, and 180 mm evaporation from Class A evaporation pan, respectively. Results show that seed yield has decreased about 18% and 33% in mild and sever water deficit stresses, respectively. Yield and oil percentage are affected by hybrids and the interaction of year and stress. Barzegar hybrid, with an average of 2846 kg/ha, has had the highest grain yield. It is also in the top group with 43.65% oil. Yield and seed oil percentage are affected by environmental conditions of years, while water deficict stress has no significant effect on oleic and linoleic acids. However, there is a strong negative correlation between oleic and linoleic acids. Hysun 25 and Sirena cultivars are suitable for oil production with higher oleic acid and Barzegar and G6×R-43 are suitable for oil production with higher linoleic acid.