The effect of super absorbent polymer on yield and yield components of sunflower (Helianthus annuus L.) under drought stress conditions

The application of superabsorbent polymeric materials may prevent yield reduction of some crops under drought stress conditions. To investigate the effect of adsorbent polymer consumption on yield and yield components of sunflower under drought stress conditions, an experiment was conducted as a split plot in a randomized complete block design with 3 replications in a farm located 20 km away from Sabzevar during 2013-2014. Factors were irrigation regimes (12-day and 24-day intervals) as main plot and different amount of super absorbent polymer (0, 30, 60, 90 and 120 kg ha-1) as subplot. The results showed that plant height, number of seeds per head, percentage of empty seeds, 100-seed weight, economic yield and biological yield were significantly affected by irrigation intervals. Increasing the irrigation interval reduced plant height by 26.3%, number of seeds per head by 39.5%, 100-seed weight by 17.9%, economic yield by 31.2% and biological yield by 17.9%. The highest yield and yield components were obtained at application of 120 kg ha-1 superabsorbent polymer and the lowest at control treatment. Although the yield response to the use of superabsorbent polymer was higher in the 12-day irrigation interval, use of superabsorbent polymer reduced the negative effects of drought stress. In 12-day irrigation interval, consumption of 120 kg ha-1 absorbent polymer and in the 24-day irrigation interval, consumption of 30 kg ha-1 absorbent polymer produced the maximum net income. In total, the highest grain yield and economic income were obtained at application of 120 kg ha-1 superabsorbent and 12-day irrigation interval.