Influence of water deficit and genotype on protein, oil contents and some physical characteristics of sunflower seeds

Water deficit stress and genotype effects on crude protein, oil content and some physical properties of sunflower seeds were investigated. The analyses indicated that, water deficit stress and varietal difference influenced the proximate composition of sunflower seeds. The seeds from Azargol and Hysun 33 cultivars were found to have the highest and lowest oil contents of 45 and 42% respectively, while the seeds from Hysun 25 and 33 cultivars had the highest and lowest protein contents of 39 and 32% respectively. In general, as the water supply decreased oil content and physical characteristics of each cultivar were negatively affected, but protein content of each cultivar was positively affected. The cultivar with the highest protein content in well-watered and water deficit stress condition (irrigation after 50 and 150 mm cumulative evaporation from class A evaporation pan, respectively) had the following mean physical properties: length of 9.68 ± 0.5 and 7.44 ± 0.6 mm, width of 6.52 ± 1.3 and 4.21 ± 0.4 mm, thickness of 4.08 ± 0.51 and 3.11 ± 0.004 mm, volume of 142.7 ± 18.6 and 52.11 ± 1.8 mm3, surface area of 105.7 ± 5.6 and 55.9 ± 1 mm2, mass of 55.7 ± 1.2 and 28.4 ± 1.3 g and moisture content of 11.4 and 9.8% (d.b).