Impact of the foliar application of nanoparticles, sulfate and iron chelate on the growth, yield and nitrogen assimilation in green beans

Nano-fertilizers (Nfs) have the potential to revolutionize agricultural systems through nanostructures ranging from 1 to 100 nm that address environmental responses and a more targeted biological demand. The purpose of this work was to study the impact of the foliar application of nanoparticles (NPs), sulfate and iron chelate on the growth, yield and assimilation of nitrogen in green beans. The iron was applied foliar in three different ways: Iron oxide nanoparticles (Fe2O3), ferric sulfate (Fe2(SO4)3) and iron chelate (Fe-EDDHA) in doses of 0, 25, 50, 100 and 200 ppm. The treatments that produced a higher total biomass increase were NPs and Fe-EDDHA at 50 ppm, with increases of 37% and 47% respectively compared to the control (with no application of Fe). Regarding the in vivo nitrate reductase activity, significant differences were obtained, particularly in the NPs and Fe-EDDHA treatment, with increases of 71% and 72% respectively. NPs at low doses favored maximum fruit production with increases of 88% in comparison to the control. Finally, it is concluded that the optimal doses that enhanced total biomass, production and assimilation of nitrogen were Fe2(SO4)3 at 25 ppm, Fe-EDDHA at 100 ppm and Fe2O3 at 25 ppm. The efficiency of foliar absorption of iron was found in treatments with Fe2O3 at 50 and 100 ppm. The foliar absorption efficiency of NPs offers sustainable alternatives to increase the productivity of the green bean.