Effect of Different Ratios of Potassium to Magnesium on Some Fruit Yield and Quality Attributes of Hydroponicly-grown Strawberry (Fragaria×Ananassa Duch. Cv. Albion)

An imbalanced nutrients status in the nutrient solution, i.e. poor nutrition of the plant, is often responsible for the low quantity and quality of strawberry fruit. The present study was conducted to investigate the effect of different ratios of potassium to magnesium (K/Mg) (T1, 2:1, T2, 4:1, T3, 6:1 and T4, 8:1) on fruit yield and quality of strawberry cv. Albion under hydroponic conditions. Different K/Mg treatments did not have a significant effect on fruit yield and quality attributes such as ascorbic acid and total soluble solids. The highest fruit yield was obtained when plants were exposed to a 4:1 ratio (i.e. T2). Fruit quality attributes such as total anthocyanin, total antioxidant, total phenolic, total flavonoids, total chlorophyll, calcium, Mg, and K concentrations in the leaves and antioxidant enzymes activities were significantly affected by the K/Mg treatments. The highest total phenolic (925 mg/100g FW) and total flavonoids (163 mg/100g FW) were observed when plants grown in the presence of a 4:1 ratio (i.e. T2). Whereas, the highest antioxidant activity (89.2%) was detected in plants exposed to the 8:1 ratio (T4). The highest activity of guaiacol peroxidase (2.88 and 2.78 unit/g FW), ascorbate peroxidase (2.11 unit/g FW), and catalase (2.23 unit/g FW) were observed in T3 and T4, T4, and T4 treatments, respectively. It can be concluded that among the tested treatments, the 4:1 ratio of potassium:magnesium is optimal for the strawberry production.