Abstract

The objective of this research was to compare the applications through drench (on the surface of the substrate) and foliar application of Fe2O3 nanoparticles (Fe2O3 NPs) against a conventional Fe fertilizer (Fe-EDTA) in Raphanus sativus L. plants established in a soilless system under a greenhouse. The seeds of the cv. Champion were sown in 2 L pots with a mixture of peat moss:perlite in a 1:1 ratio. A 50% concentrated Steiner solution supplied plant nutrition. Fourteen days after sowing, the applications of the treatments began. Treatments consisted of foliar and drench applications of Fe-EDTA and Fe2O3 NPs. The standard amount of Fe applied in a radish on a soilless system (13 mg plant −1) was taken as a reference. The control treatment was the application of Fe-EDTA by drenching, while the same product was also applied via foliar application. Fe2O3 NPs were applied at 100, 75, and 50% for control through foliar and drench application. The treatments were administered weekly, giving a total of four applications. The results showed that the dimensions and biomass of the R. sativus root increased in ranges of 20–30% when applying Fe2O3 NPs, as well as the concentration of chlorophylls in the leaves by 18–38%. Similarly, increases between 24 and 147% were found in the levels of vitamin C, GSH, and antioxidant capacity in leaves and roots, in addition to a greater activity of antioxidant enzymes. The K concentration rose between 35 and 48% in leaves and roots, while Fe levels increased up to 40% in leaves. On the other hand, Fe2O3 NPs showed a fertilizer use efficiency (FUE) up to 42% higher than that of Fe-EDTA. In conclusion, the results indicate that the complete replacement of Fe-EDTA with Fe2O3 NPs is possible, improving the yield and quality of R. sativus and obtaining a better FUE.