Optimizing drip irrigation density enhances growth, yield, physiology, and antioxidant capacity of Korean strawberry ‘Kuemsil’ in recycling hydroponics

Efficient irrigation management is crucial for improving water-use efficiency and maintaining high productivity in controlled-environment strawberry cultivation. This study evaluated how different drip irrigation densities influence the growth, physiological responses, yield, fruit quality, mineral uptake, and antioxidant activity of the ‘Kuemsil’ strawberry cultivar grown in a recycling hydroponic system. Three irrigation densities, D3 (three drippers at 25 cm spacing), D6 (six drippers at 15 cm spacing), and D9 (nine drippers at 10 cm spacing) were compared under coir-substrate cultivation from October 2024 to May 2025. Increasing dripper density generally improved plant performance, with D6 (moderate) and D9 (high) irrigation densities promoting better vegetative growth, photosynthetic efficiency, water status, and nutrient balance compared with the D3 (low-density) treatment. Plants under low irrigation distribution showed reduced physiological performance and greater energy dissipation, indicating higher stress levels. Although the highest irrigation density increased total fruit production, the moderate irrigation density provided the best balance between marketable yield and fruit quality by reducing the proportion of unmarketable fruits and enhancing the production of larger fruits. In addition, the moderate irrigation density improved antioxidant capacity and membrane stability, suggesting enhanced physiological resilience under recycling hydroponic conditions. The findings demonstrate that optimizing drip irrigation density is critical for maximizing strawberry productivity and fruit quality while supporting efficient water and nutrient use in sustainable hydroponic production systems. The moderate irrigation density was identified as the most effective strategy for achieving balanced growth, yield, and physiological performance in ‘Kuemsil’ strawberry cultivation.