Fig. 6From: Improved iron use efficiency in tomato using organically coated iron oxide nanoparticles as efficient bioavailable Fe sourcesShoot total Fe of (a) bulk FeSO4 vs. Fe3O4 NPs, (b) iron citrate vs. Fe3O4@CA, (c) iron humate vs. Fe3O4@HA, and (d) Fe-EDTA vs. Fe3O4@EDTA NPs. The standard error is indicated by the error bars (n = 3). Different letters indicate differences between treatments (p < 0.05). The shoot total Fe has been reported based on mg of Fe per Kg of shoot dry mass. The concentration of iron fertilizers has been reported based on mg of Fe per Kg of soilBack to article page