Effect of Different Fertilizing Methods on Zinc Nutrition in Zn-Deficiency Apple Trees

Red Fuji apple trees of Zn-deficiency were used as material in the experiment. The effect of different Zn application methods on the regularity of Zn transportation and nutrition was studied. It was found that the storage of Zn in the branches was greatly increased by foliar application of the solution of 15% ZnSO4•7H2O before abscission. It had advantage to keep suitable Zn content in leaves, branches and roots, as well as between Zn and P and K, which increased Zn transportation and reusability. Zn content in roots increased when Zn was used in soil in autumn. However, the absorbed Zn did not transport to the top of the plant. It was used by the plant next year. Foliar application of ZnSO4•7H2O at early stage of the plant growth enhanced Zn content of the branch. However, the effect was kept for a short time. It had little effect on Zn transportation when Zn was sprayed three weeks after blossoming.