Nitrate and sucrose content in fresh-cut leaves of spinach plants grown in floating system

Leafy vegetables quality can be improved by an optimization of crop growing management. The physiological studies are required for understanding the plant responses in the early development stage at different mineral concentrations. The aim of this work was to investigate the effect of macronutrient concentrations on yield and baby leaf quality. The experiments were performed on spinach (Spinacia oleracea L.) plants grown in floating system with three reduced Hoagland’s solution: NS10%, NS10%: 1.3 N-NO3, 0.15 P, 0.8 K, 0.35 Ca, 0.17 Mg; NS25%: 3.2 N-NO3, 0.37 P, 2 K, 0.85 Ca, 0.42 Mg; NS50%: 6.5 N-NO3, 0.75 P, 4 K, 1.75 Ca, 0.85 Mg. Other mineral elements were the same in all treatments: 9.5 Na, 8.0 Cl, 2.7 S, 0.04 Fe and Hoagland’s concentration for micronutrients. Yield, nitrates, sucrose content, chlorophyll, chlorophyll and lipid peroxidation were measured at harvest time. Results showed that yield, nitrates content and sucrose content increased by increasing macronutrient concentrations in the nutrient solutions. Chlorophyll a fluorescence, chlorophyll, carotenoids and lipid peroxidation did not change among treatments.