Iron chelate is a complex in which a ferric or ferrous ion is linked through an organic ligand like EDTA (ethylenediaminetetraacetic acid) to form a ring structure. This complex, commonly used for soil application, increases the quantity of iron transported to the plant roots by mass flow and diffusion. It can be sprayed on foliage. Fe-EDDHA (iron-ethylenediamine di-o-hydroxyphenylacetic acid) can be used as an iron fertilizer because of its affinity to iron.
The chemical structure of EDDHA is given in Fig.I.7.
