Application of Sargassum boveanum Extract under Water Deficit Conditions to Investigate Its Effects on the Relative Water Content, Photosynthetic Pigments and Mineral Elements of Corn (Zea mays)

In this study, we evaluated the effects of water deficit stress on some biochemical traits of maize using Sargassum boveanum liquid extract (LESb) in greenhouse experiment. Which included three factors: non-stress conditions (80% field capacity (FC)) and water deficit stress (60 and 40% FC), along with five concentrations of seaweed extract (0.0, 1.0, 1.5, 2, and 2.5% V/V). Water deficit notably reduced plant growth, A 1.5% extract concentration under 60% FC stress improved chlorophyll a content by 10.63% compared to 0%. Under 80% FC, chlorophyll b content increased by 22.22 and 26.86% for concentrations of 1.5 and 2%, respectively. Additionally, carotenoid content rose by 17.94 and 30.43%, while total chlorophyll content increased by 29.17% at the 1.5% concentration compared to the 0% concentration. The highest Fv/Fm was noted with 1.5% under both 80 and 60%. The relative water content (RWC) was under 60 and 40%, at 9.65 and 20.31%, respectively. Additionally, the dry weight of the shoot increased by 27.55 and 57.52%. The K+ content increased by 14.52, 7.15, and 26.26% under 80, 60, and 40% conditions, respectively, with a concentration of 1.5%. An increase in Ca+2 content was observed at 60% for concentrations ranging from 1% to 2%, while an increase in Mg content was noted at 40% with concentrations of 1.5 and 2% compared to 0%. The 1.5% LESb concentration improved corn plant traits during water stress, minimizing negative impacts and effectively alleviating water deficit stress. It also served as a beneficial biological stimulant, especially under normal conditions.