Foliar Spray of Fe-Asp Confers Better Drought Tolerance in Sunflower as Compared with FeSO₄: Yield Traits, Osmotic Adjustment, and Antioxidative Defense Mechanisms

• Main Authors: Qasim Ali, Shafaqat Ali, Mohamed A. El-Esawi, Muhammad Rizwan, Muhammad Azeem, Abdullah Ijaz Hussain, Rashida Perveen, Mohamed A. El-Sheikh, Mohammed Nasser Alyemeni, Leonard Wijaya
• Format: Article
• Language: English
• Published: MDPI AG 2020-08-01
• Series: Biomolecules
• Subjects: water relations; seed yield; antioxidative defense mechanism; amino acids; nutrient uptake
• Online Access: https://www.mdpi.com/2218-273X/10/9/1217

Different techniques are being employed to reduce the adverse effects of water stress on seed yield and quality of crop plants. The current study aimed to improve the water stress tolerance of field-grown sunflower by foliar-supplied ecofriendly iron-chelated aspartate (Fe-Asp) in comparison with FeSO₄. Water stress decreased the plant growth and yield, accompanied with disturbed water relations, nutrient acquisition, accumulation of amino acids, and antioxidative defense mechanisms. However, lipid peroxidation, total anthocyanin, and photosynthetic pigments were increased. Fertigation of FeSO₄ and Fe-Asp as foliar sprays proved effective to reduce the negativities of limited irrigation on biomass production and seed yield, accompanied with a reduction in lipid peroxidation and improvements in water relations, antioxidative defense mechanisms, and leaf photosynthetic pigments. In comparison with FeSO₄, foliary applied Fe-Asp better improved the plant water relations with more accumulation of essential amino acids and nutrient acquisition, especially leaf aspartate (Asp) and Fe accumulation which showed better translocation. Overall, foliary applied Fe-Asp proved better for induction of drought tolerance in sunflower plants as compared with FeSO₄. The study recommended the use of the ecofriendly Fe-Asp as a foliar spray for better growth and production of sunflower under limited irrigation.