Diagnostic practices to identify iron deficiency in higher plants

Abstract

Abstract Fe chlorosis occurs in many plant species although chlorosis of monocots and dicots generally occurs under different soil and climatic conditions. Because an understanding of causal factors for chlorosis is important in diagnosis, the factors which promote iron chlorosis and the regulation of Fe uptake potential are reviewed. Extractable soil Fe is useful in diagnosing soils which will produce chlorotic monocots, but air‐drying soils increases extractable Fe unequally among soils. Certain enzyme changes with microelement deficiencies have been considered as diagnostic practices. However, the fundamental test for Fe deficiency remains ferrous sulfate or ferric chelate foliar sprays, or ferric chelate soil treatments. Sprays can identify Fe chlorosis whether leaves are low Fe (normal Fe deficiency), normal in Fe (inactivation or soil contamination of samples), or high in Fe (as happens with Zn toxicity‐induced chlorosis). Diagnosis is usually made through recognition of visual symptoms. Practical m...