Species-specific performance and nutritional responses of radish and red beet to zinc–manganese in sand culture

DW), while radish accumulated more sodium (Na) in tuber tissues. Nitrate concentrations were significantly affected by Zn-Mn interactions, with up to 6-fold differences between treatments, and high Zn generally reducing nitrate accumulation. We conclude that optimal Zn-Mn ratios are species-dependent; specifically, the combination of 10 mg L⁻¹ Zn with 0.05 mg L⁻¹ Mn promoted the highest tuber biomass yield and most favorable nutrient balance in both species. These results provide practical guidelines for micronutrient management in sand-culture vegetable production systems, although further validation under field conditions is warranted.