The Fe chelate o,p-EDDHA/Fe 3+ , in addition to o,o-EDDHA/Fe 3+ , was found recently to be a component of commercial EDDHA/Fe 3+ chelates. The European Regulation on fertilisers has included o,p-EDDHA as an authorized chelating agent. The efficacy of o,o-EDDHA/Fe 3+ , o,p-EDDHA/Fe 3+ and EDTA/Fe 3+ chelates as Fe sources in plant nutrition was studied. Iron-chelate reductase (FC-R) in young cucumber plants (Cucumis sativus L.) roots reduced o,p-EDDHA/Fe 3+ faster than o,o-EDDHA/ Fe 3+ , EDTA/Fe 3+ and a commercial source of EDDHA/Fe 3+ . The o,p-EDDHA/Fe 3+ chelate was also more effective than the o,o-EDDHA/Fe 3+ in decreasing the severity of Fe-deficiency chlorosis in leaves of young soybean (Glycine max L.) plants grown hydroponically. The o,p-EDDHA ligand was more effective in the short-term than the EDTA and o,o-EDDHA ligands at dissolving Fe from selected Fe minerals and soils. However, the ultimate quantity of dissolve Fe was greatest with the o,o-EDDHA ligand.Abbreviations: BPDS -Bathophenanthroline disulfonic acid or 4,7-diphenyl-1,10-phenantroline disulfonic acid; EDDA -ethylene diamine diacetic acid; EDTA -Ethylene diamine tetraacetic acid; FC-R -Iron chelate reductase; HEPES -4-(2-Hydroxyethyl)piperazine-1

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The optimum reflection of the solar spectrum at well‐defined incident directions as well as its durability in time are, both, fundamental requirements of the optics of thermosolar and photovoltaic energy conversion systems. The stringent high performance needed for these applications implies that, almost exclusively, second face mirrors based on silver are employed for this purpose. Herein, the possibility to develop solar mirrors using other metals, such as copper and aluminum, is theoretically and experimentally analyzed. It is found that reflectors based on these inexpensive metals are capable of reflecting the full solar spectrum with efficiencies comparable to that of silver‐based reflectors. The designs herein proposed are based on aperiodic metal‐dielectric multilayers whose optimized configuration is chosen employing a code based on a genetic algorithm that allows selecting the best one among 108 tested reflectors. The use of metals with wider spectral absorption bands is compensated by the use of multilayered designs in which metal absorption is almost suppressed, as the analysis of the electric field intensity distribution demonstrates. The feasibility of the proposed mirrors is demonstrated by their actual fabrication by large area deposition techniques amenable for mass production.