Mahshid Ghafouri - Department of Horticultural Sciences, Faculty of Agriculture, University of Zanjan, Zanjan, Iran
Farhang Razavi - Department of Horticultural Sciences, Faculty of Agriculture, University of Zanjan, Zanjan, Iran
Masoud Arghavani - Department of Horticultural Sciences, Faculty of Agriculture, University of Zanjan, Zanjan, Iran
Ebrahim Abedi Gheshlaghi - Department of Horticulture Crops Research, Guilan Agricultural and Natural Resources Research and Education Center, AREEO, Rasht, Iran

Purpose: The application of natural organic compounds without harmful environmental effects in the production of horticultural and agricultural products is considered as a new method to reduce waste before and after harvesting, increase the storage life and maintain antioxidant activity in developed agriculture. As regards, this study investigated the impact of foliar applications of brown macroalga extract on antioxidant enzyme activity and mineral uptake in 'Hayward' kiwifruits. Research method: Four treatment levels of brown macroalga extract (۰, ۱, ۲, and ۳ g/L) were applied at three distinct phases, occurring ۱۱۰, ۱۲۵, and ۱۴۰ days after full bloom. Fruit samples were stored at ۱±۰.۵°C with ۹۵% relative humidity for ۹۰ days, with measurements taken every ۳۰ days. Findings: Results revealed that the ۳ g/L extract treatment significantly increased the uptake of calcium (۴۷.۸۲ %), nitrogen (۲۰.۵۲ %), potassium (۱۲.۰۶ %), phosphorus (۱۹.۸۱ %), and iron (۲۵.۷۷ %) compared to the control. The extract demonstrated a substantial effect on all recorded traits. Among the applied treatments, ۳ g/L of brown macroalga extract concentration had the best effect in reducing electrolyte leakage (۲۵.۱۰%), malondialdehyde accumulation (۹۶.۷۳%), hydrogen peroxide content (۵۴.۵۴%) and increasing activities of antioxidant enzymes including superoxide dismutase (۵۰.۴۲%), catalase (۸۴.۹۰%), ascorbate peroxidase (۷۹.۰۲%), and peroxidase (۴۹.۴۰%) compared to the control in ۹۰ days of storage. Research limitations: No limitations were found. Originality/Value: The results suggest that the ۳ g/L brown macroalga extract concentration holds promise for enhancing the quality of 'Hayward' kiwifruits.

Catalase, Hydrogen peroxide, Malondialdehyde, Preharvest treatment, Superoxide dismutase