Iron Biofortification of Greenhouse Soilless Lettuce: An Effective Agronomic Tool to Improve the Dietary Mineral Intake

The present experiment addressed the effects of different iron (Fe) concentrations in nutrient solution supplied as Fe-HBED, i.e., 0.02 (Fe0, control), 1.02 (Fe1), and 2.02 mmol L−1 (Fe2) on lettuce (‘Nauplus’ ‘Romana’) yield compositional traits. This was carried out a greenhouse using an open soilless cultivation system, at experimental farm University Catania (Sicily, Italy: 37°24′31.5″ N, 15°03′32.8″ E, 6 m a.s.l.). addition Fe-HBED reduced plants’ aboveground biomass (−18%, averaged over Fe1 Fe2), but promoted their dry matter content (+16% Fe2). concentration chlorophylls, carotenoids, anthocyanins, antioxidants peaked Fe2, along with antioxidant capacity stress indicators leaves. Fe leaves Fe-treated plants (+187% ‘Romana’ showed highest accumulation (reaching 29.8 mg kg−1 FW Fe1), ‘Nauplus’ proved higher tolerance to Fe-derived oxidative stress. Fe2 treatment maximized leaf P, K, S, Zn contents, while those Ca, Mg, Mn, B Fe1. Overall, our study revealed effectiveness increasing improving nutritional quality grown systems.