Effects of Different Fertilization Treatments on Fruit Quality, Biochemical Contents, and Mineral Composition of Strawberry

Foliar fertilization may increase strawberry yield and quality while reducing the environmental load of soil fertilization. The study was conducted as a field experiment with three replications according to a randomized block design at the Erciyes University Agricultural Research and Application Center (Kayseri, Türkiye). This study investigated the effects of different foliar fertilizer treatments (Dogatech Combi, Axion, and Dogatech Borozinc) on fruit morphological traits, SPAD values, leaf and fruit mineral element composition, and biochemical contents of the ‘Albion’ strawberry cultivar. Foliar fertilizer treatments significantly affected fruit traits. Dogatech Borozinc treatment produced the highest yield per plant (688.00 g plant−1) and the largest fruit, with a mean fruit weight of 15.59 g. Dogatech Combi (T1; 111.84) and Dogatech Borozinc (T3; 111.27) showed significantly higher fruit a* values (redness) than the control treatment (82.27). Dogatech Combi significantly increased mineral concentrations in the fruits, and showed the greatest effect on all elements (particularly Ca (19,453.05 mg kg−1 DW) and K (17,496.42 mg kg−1 DW)). Among the biochemical characteristics, Axion showed the highest total phenolic content in fruits (487.72 mg GAE 100 g−1) and leaves (2042.49 mg GAE 100 g−1). The total flavonoid content of fruits and leaves was highest in the Dogatech Combi, while Dogatech Borozinc exhibited the highest DPPH radical-scavenging activity of fruits and leaves and the fruit anthocyanin content. Principal component analysis (PCA) and heatmap hierarchical clustering analysis revealed distinct patterns among the fertilizer treatments. Overall, since foliar fertilizer responses vary depending on the formulation, fertilizer selection in strawberry cultivation should be based on production objectives.