Optimizing sunflower performance through integrated irrigation and zeolite strategies in the north Nile Delta

Abstract Two field studies were conducted at the Sakha Agricultural Research Station farm, Kafr El-Sheikh, Egypt, to evaluate zeolite and deficit irrigation through skipped irrigation events for sunflower. A split-plot statistical design was applied. Three irrigation regimes, i.e., irrigation every 12–15 days (I1, as a conventional irrigation), irrigation every 12–15 days but skipping the third irrigation event at 35 DAS (days after sowing) as I2, and skipping the sixth irrigation event at 65 DAS as I3. Three zeolite applications (i.e., no zeolite addition as a control, F1) and adding zeolite at a rate of 595 kg ha − 1 (F2) and 1190 kg ha − 1 (F3) for the subplot units. Results indicated that skipping irrigation events decreased leaf area by 9–13%, photosynthetic pigments by 9–16%, relative water content by 4–12%, seed yield by 10–14%, and seed oil percentage by 5–9%. All zeolite application rates significantly improved sunflower growth and productivity compared with no zeolite addition. The highest values of the studied traits were obtained under the conventional irrigation combined with zeolite application. Moreover, I1F2 treatment achieved the highest net return ($4,975.92 ha⁻¹) and economic water return (0.75 $ m − 3 ) compared with the other interaction treatments. Overall, zeolite application effectively enhanced sunflower growth and productivity under water-stress conditions.