Iron (Fe)

The micronutrient iron (Fe) is absorbed as Fe2+ and Fe3+. Primary function of Fe in the plant is related to its ability to undergo a valence change from Fe2+ to Fe3+. It is also a component of two major protein groups including the heme proteins and the Fe-S proteins.

Iron is not mobile in the plant, which results in deficiency symptoms occurring first in the younger tissue and is exhibited as interveinal chlorosis, which under severe cases may become white and devoid of chlorophyll.

Soil Fe availability is highly dependent upon soil solution pH just as many of the other metal micro-nutrients. Iron deficiency may be observed despite its presence in the soil if the following conditions exist: soil high in Ca, poorly drained soil, soil high in Mn, high pH, high P, soil high in heavy metals (Cu,Zn), oxygen deficient soils or when nematodes attack the roots. The use of chelated Fe fertilizers will help improve the efficiency of soil applied Fe.

Images of Iron deficiency symptoms

Iron deficiency symptoms on tomato.