The study on controlling the rosette disease of red Fuji apple trees

The methods of controlling the rosette disease of red Fuji apple trees were studied through various dilutions of ZnSO₄·7H₂O spraying toleavesin autumn and various dilutions of ZnSO₄·7H₂O，NAA and ZnSO₄·7H₂O+NAA spraying to branchlets before sprouting ．The results show that it is better to control small-leaf-rosette disease of apple tree by spraying ZnSO₄。7H₂O in autumn，spraying ZnSO₄。7H₂O and the mixed solution of ZnSO₄·7H₂O and NAA before sprouting．The controlling effects are very significant by spraying 100g／kg ZnSO₄·7H₂O in autumn，spraying 100g／kgZnSO₄·7H₂O，150g／kgZnSO₄。7H₂O and l00／kgZnSO₄·7H₂O+2．0mg／kg NAA，loog／kg ZnSO₄·7H₂O+4．0mg／kg NAA before sprouting ．The shoots length，leaf area，chlorophyll and Zn contents in leaves are significantly increased，and the rosette disease shoots percentage are significantly declined ．