Abstract: The present study was carried oat in Changtai, Piaghe and Nanjing counties of south Fujian during 1990-1991 in order to find out the optimum range of the mineral element content in the leaves of Yinzigan, Gailiang and Valencia orange, which were major cultivars of sweet orange (Citrus sinensis) in south Fujian. The main results are as follows. The amount of macro-and micro-elements in the leaves within the same cultivars was affected by different locations and years of sampling. The difference of the contents of nutrient elements among the three cul-tivars was not steady. The authors therefore suggested that it was pertinent to establish the common criteria of plant nutrient diagnosis for the three sweet orange cultivars. The statistical analysis indicated that the variation coefficients of N and P contents in the leaves were lower, while those of Mg,K and Ca contents were higher; the variation coefficients were higher for most micro-element contents (especially B, Mn and Cu) in the leaves than those for macro-element contents. The preliminary study suggested that the values of optimum range of leaf mineral elements in spring shoot of productive sweet orange were s N 2.50-3.30%, P 0.12-0.18%, K 1.00-2.00%, Ca 2.00-5.00%, Mg 0.22-0.40%, Cu 4.0-18.0 ppm, Zn 25.0-70.0 ppm, Mn 20.0-100.0 ppm, Fe 90.0-160.0 ppm, B 25.0-300.0 ppm, and the optimum ratio between the amount of macro-elements in leaves was N:P:K:Ca:Mg=1:0.05:0.52:0.95:0.11. These diagnostic criteria may provide the parameters of fertilizer guide.

Key words: Sweet orange, Cultivar, Coefficient of variation, Nutrient diagonsis, Optimum range of leaf element content

摘要： 本研究探讨闽南甜橙主栽品种(印子柑、改良橙、伏令夏橙)叶片营养元素含量的适宜范围。结果表明,各品种不同地点、年份的叶片元素含量存在明显差异,而三个甜橙品种间叶片元素含量未见稳定的差异,因此,作者认为,可建立三个甜橙品种通用的叶片营养元素含量适宜标准。统计分析表明:其叶片毛素含量的变异系数,大量元素以氮、磷较小,镁、钾、钙较大;微量元素多高于大量元素。本文初步提出甜橙于片元素的适宜含量:氮2.50%~3.30%,磷0.12%~0.18%,钾1.00%~2.00%,钙2.00%~3.50%,镁0.22%~0.40%,铜4.0~18.0 ppm,锌25.0~70.0 ppm,锰20.0~100.0 ppm,铁90.0~160.0 ppm,硼25.0~100.0 ppm。大量元素含量的适宜比值为氮:磷:钾:钙:镁=1:0.05:0.5:2:0.95:0.11。上列指标可供甜橙营养诊断指导合理施肥之参考。

关键词: 甜橙, 品种, 变异系数, 营养诊断, 叶片元素适宜含量