Abstract: The newhall navel citrus (Citrus sinensis Osbeck ‘Newhall’) tree was used as the material. In the summer shoot growth period, controlling water and fertilizer was used as a treatment(T1), and the NPK water soluble fertilizer was applied by drip irrigation as control (CK). During the autumn shoots growth period, the controlling water and fertilizer treatment (T2) was applied to the trees which was applied by CK and T1 treatment in summer. Shooting rate, shooting density, shoot length, shoot thickness and leaf number of shoot were surveyed after the summer shoots and autumn shoots were matured, respectively. The results showed that T1 treatment significantly reduced the summer shoot shooting rate, summer shoot length, summer shoot thickness and leaf number of newhall navel orange. Compared with the CK+T2 treatment, the length of autumn shoots in T1+T2 treatment decreased significantly, and the proportion of short shoots in T1+T2 treatment increased, the growth of summer and autumn shoots was restricted to some extent. The results laid a foundation for the research and development of water controlling measures or fertilization frequency in the actual production process to achieve the labor-saving and effective regulation of citrus shoot growth.

Key words: citrus, Citrus sinensis Osbeck ‘Newhall’, shoot growth, control shoot growth, control water and fertilizer