Optimum Range of Mineral Element Contents in the Leaves of Guanxi Honey Pomelo(Citrus grandis)

The optimum ranges of macro-and micro-clement contents in the leaves of Guanxi Honey Pomelo in south Fujian of China were studied in 1988-1989.The main results are as follows.The amount of macro-and micro-elements in the leaves within the same cultivar was affected by different locations and years of sampling.Furthermore, data from the statistical analysis indicated that the variation coeffecients of N and P contents in the leaves were lower, while that of Mg, K and Ca have been increasing successively.The variation coefficients were higher for most micro-element contents(especially B and Mn)in the leaves than that for macro-element contents.The present study recommends that the values of the optimum ranges of the mineral elements in the leaves of spring shoots of Guanxi Honey Pomelo are N 2.50-3.10%, P 0.14-0.18%, K 1.40-2.20%, Ca 2.00-3.8%, Mg 0.32-0.47%, Cu 8.0-17.0ppm, Zn 24.0- 44.0ppm, Mn 15.0-140.Oppm, Fe 60.0-140.0ppm, B 15.0-50.0ppm.These diagnostic criteria may provide the parameters of fertilizer guide.