Hydroponically grown corn (Zea mays) is highly susceptible to Fe-chlorosis. Iron (Fe) is essential for chlorophyll synthesis. Metals bound to chelates have reduced bioavailability (activity) compared to free ions.
Kusuma, Paul; Bugbee, Bruce. Reduced Chelate Strength Increases Iron Bioavailability for Monocots in Hydroponic Culture (2022).