Rosette and little leafat the shoot tip are the most characteristic symptoms of Zn defi-Rosette and little leafat the shoot tip are the most characteristic symptoms of Zn defi-ciency in fruit trees (Swietlik, 2002). In marginally Zn deficient soils,yield and quality
can be affected without the obvious appearance ofsymptoms; this is called ‘hidden’
(or ‘latent’) deficiency (Alloway,2008, 2009). Some studies have reported that dry
matter produc-tion is reduced by 40% or more by hidden Zn deficiency (Carroll
and Loneragan, 1968). Given these circumstances, the understand-ing to the intrinsic
changes in the physiological processes of leavesaffected by hidden Zn deficiency
may be helpful to determine theinitial damages caused by Zn deficiency along with
the final devel-opment of deficiency symptoms.