Iron deficiency is a common disorder affecting crop plants world-wide. This problem has a great economic significance for plant production and its correction requires the use of expensive methods such as the application of iron foliar sprays. However, variable results concerning leaf Fe treatments have been often reported due to the manifold factors involved in the process of leaf iron penetration and the subsequent iron delivery to plant cells.

 

In this review an account of key factor related to the process of leaf iron penetration is given. Information concerning leaf penetration principles and the physical chemistry of the applied solution (surfactant action, iron chemistry, environmental effect) is combined within the frame of plant iron biology and some conclusions are extracted regarding the effectiveness of iron fertilisers.