Effect of Superabsorbent Polymer and Potassium Sulfate on Quantitative and Qualitative Yield of Sesame (Sesamum indicum L.) under Water Deficit Conditions

In order to investigate the application of superabsorbent polymer and potassium sulfate under deficit irrigation condition on quantitative and qualitative yield of sesame, a factorial experiment in a randomized complete block design with three replications was conducted in the research farm of Birjand University in 2018. Experimental factors include three levels of irrigation (full irrigation, irrigation up to 50% of flowering and irrigation up to 50% of capsule emergence), three levels of potassium fertilizer (non-use, application based on fertilizer recommendation and 1.5 times fertilizer recommendation) and two levels of superabsorbent (Zero and 100 kg.ha-1). With stopping irrigation, grain yield, biological yield, harvest index, oil percentage, oil yield and protein percentage decreased but leaf potassium percentage increased. The highest grain yield was under normal irrigation conditions (2342 kg.ha-1) and the lowest was under irrigation conditions at flowering stage (668 kg.ha-1). The interaction effect of irrigation in superabsorbent on grain yield, harvest index, oil percentage and oil yield was significant. Consumption of superabsorbent reduced the negative effects of stress and improved traits. Also, potassium consumption in soil was associated with increased potassium accumulation in leaves. The simultaneous use of superabsorbent and potassium sulfate did not have a significant effect on growth and yield, but the use of potassium fertilizer due to the modification of drought stress and superabsorbent due to its role in reducing the effects of water shortage and improving drought stress tolerance is recommended to maintain yield.