Contents of Main Nutrients in Leaves of ‘Jianyang Juyou’

[Objectives] This study aimed to understand and master the nutritional characteristics of ‘Jianyang Juyou’ growing in southern Guangxi, with a view to providing a theoretical basis for the rational fertilization of local orchards. [Methods] The leaves of 3-year-old ‘Jianyang Juyou’ were sampled according to the phenological characteristics, and the dynamics in the contents of macronutrients and main trace elements N, P, K, Ca, Mg, Fe, Zn and B in the leaves were analyzed. [Results] The average contents of N, P and K in the leaves of ‘Jianyang Juyou’ were in the order as N > K > P. Among them, the content of N reached the highest during the flowering period and then decreased; K maintained a high content around the fruit enlargement period; the Ca content of leaves is significantly greater than that of Mg, and the peak value of Ca content appeared during the flowering and color change periods; the Mg content increased from the germination stage to the late fruit enlargement stage, while decreased in the color change stage; the average contents of main trace elements in the leaves ranked as Fe > B > Zn; the Fe content gradually increased from the germination stage to the physiological fruit drop stage, and slowly decreased after the fruit enlargement; the Zn content peaked in the physiological fruit drop period and fruit maturity period; and the B content of the leaves was 81.6-87.2 mg/kg during the flowering period, the early period of fruit enlargement, the late period of fruit enlargement, and the color change period. [Conclusions] During the phenological period, the leaves of ‘Jianyang Juyou’ had a higher demand for N, and the peak absorption period was mainly concentrated from the germination period to the early period of fruit enlargement; the demand for K was second only to N, and the peak absorption period was concentrated in the early stage of fruit enlargement to the mature stage; and the demand for P was minimal. In the production of ‘Jianyang Juyou’ Mg played an important role in promoting budding and blooming, preserving flowers and fruits and promoting fruit enlargement, so attention should be paid to the application of Mg fertilizer before the color change period. During the flowering period, the early period of fruit enlargement, the late period of fruit enlargement, and the color change period, B fertilizer could be appropriately increased by soil application or foliar spraying. Due to the large fluctuation of Zn content in leaves and small mobility of Zn, it could be supplemented quickly by spraying on the leaf surface before the physiological fruit drop period and fruit maturity period.