yield and quality of sesame (sesamum indicum l.) improve by water preservative materials under normal and deficit irrigation in birjand

Crop production in dry areas is strongly affected by water shortage. in these regions, the application of water-absorbent materials is a useful strategy for sustainable crop production. therefore, the aim of this study was to investigate the effect of two water preservative materials (wpm) on the growth and yield of sesame under two irrigation regimes. the experiment was carried out as factorial based on a randomized complete block design with three replications, during 2018 and 2019. experimental factors were water availability levels (100 and 50% of sesame water requirement as normal and deficit irrigation, respectively) and application of wpm, including control (no-wpm), 125 kg ha-1 super absorbent polymer (sap), 6200 kg ha-1 zeolite (z1), 11200 kg ha-1 zeolite (z2), sap+z1 and sap+z2. at the end of both growing seasons, vegetative growth parameters, yield components, seed and biological yields, water use efficiency and seed quality indices (oil and protein contents) were measured. the highest and the lowest amounts of vegetative parameters were obtained at sap+z2 under normal irrigation and control under deficit irrigation, respectively. yield component indices were improved significantly by all wpm especially sap+z2 at both levels of irrigation. the highest seed yield was recorded by sap+z2 under normal irrigation (1304 and 1481 kg ha-1, for the first and the second growing seasons, respectively). the highest oil yield (749 and 843 kg ha-1, for the first and the second growing seasons, respectively) was gained at sap+z2 under normal irrigation, while its lowest value (125 and 136 kg ha-1, for the first and the second growing seasons, respectively) was obtained with no- wpm under deficit irrigation. similar trend was observed for protein yield. overall, despite yield reduction, deficit irrigation improved water use efficiency. moreover, wpms were useful to improve growth and yield of sesame under both irrigation regimes.