Investigation of the effect of different irrigation regimes on seed yield, antioxidant enzyme activity and some quantitative traits of sunflower cultivars

Oilseeds are considered as one of the most essential food components in human consumption as well as animal feed. While drought is one of the most important abiotic stresses in the climate change scenario and its intensity is expected to increase in the future, which has an adverse effect on the yield and nutritional quality of major oilseeds worldwide. Sunflower is an important oilseed product that has an 8% share in the production of oilseeds in the world. In order to investigate the effect of different irrigation regimes on grain yield and some physiological indices, experimental sunflower cultivars were performed in the form of split plots in a randomized complete block design with four replications in Ahvaz Agricultural Research Center during 1995 and 1996. Irrigation regime includes irrigation after evaporation of 50, 70 and 90 mm from Class A evaporation pan as no stress, mild and severe stress, respectively, in the main plots and six cultivars Progress, Farrokh, Barzegar, Rekord, Azargol and Lakomka in Sub-plots were placed. . The results of combined analysis of variance showed that the three-way effect of year, irrigation regime and cultivars was significant in superoxide dismutase, ascorbate peroxidase and grain yield and in other traits the interaction of irrigation regime and cultivars or main effects was significant. The highest grain yield (2529 kg / ha) in the first and second year of the record and irrigation of 50 mm was obtained from the evaporation pan. In general, the record cultivar had higher yields than other cultivars during all two years of experiment at all levels of irrigation. The highest amount of superoxide dismutase and ascorbate peroxidase enzymes was obtained from the record cultivar and irrigation regime of 90 mm from the evaporation pan in the second year. The results showed that the highest oil yield (1101 kg / ha) and leaf area index from evaporation stress level of 50 mm were from evaporation pan and record cultivar. The highest amount of catalase was obtained from the level of severe stress and the record cultivar. The highest amount of guaiacol peroxidase was observed in the record cultivar and the 90 mm diet from the evaporation pan. The highest amount of width (7.438 mm) and grain diameter (4.928 mm) from the application of non-stress water treatment and record cultivar and the highest grain length (13.9 mm) in Lakomka cultivar and 50 mm evaporation treatment Evaporation was obtained from the pan. According to the results of this experiment, the record cultivar and irrigation of 50 mm of evaporation pan is suitable for Ahvaz region.