Boron-mediated regulation of productivity, pomology and nutritional composition across sequential harvests in...

Strawberries are a high-value fruit with increasing global demand, owing to their flavor and rich content of biochemicals beneficial to health. Fruit quality and yield are influenced by micronutrients, particularly boron (B) that is vital for sugar transport, membrane stability and phenolic metabolism. Yet, few studies have explored how different B application methods interact with the harvest period to affect fruit quality and yield. This study evaluates the effects of soil, foliar and combined B applications across three harvest periods (March, April and May) on yield and diverse quality attributes of 'Rubygem' strawberries under Mediterranean high-tunnel conditions.

Combined B application resulted in the highest average fruit weight (24.2 g fruit^-1) and cumulative yield (810 g plant^-1), significantly exceeding the control (21.1 g fruit^-1 and 757 g plant^-1). March-harvested fruits were heaviest (36.0 g), while sugars (fructose: 3.19 g (100 g)^-1; glucose: 3.06 g (100 g)^-1) and anthocyanin content (328 mg kg^-1) peaked in May and April, respectively. Pelargonidin-3-glucoside (96.9 mg kg^-1) and ellagic acid (26.5 mg kg^-1) both reached their highest concentrations under combined B application. Citric acid reached its highest concentration (8.81 mg g^-1) in May under foliar B application. Additionally, total flavonoid content tended to increase in later harvests, particularly under foliar and combined B applications.

Combined B application improved yield and certain biochemicals, though greater productivity may reduce overall phytochemical richness due to dilution linked with fruit enlargement. Later harvests enhanced sugar and pigment accumulation via senescence-driven biosynthesis. Integrating combined B application with optimal harvest timing may ensure both productivity and quality. © 2025 Society of Chemical Industry.