以5年生薄壳山核桃品种‘波尼’（Carya illinoinensis ‘Pawnee’）幼树为实验材料，根据L₉（3³）正交试验设计进行3因子（包括植物生长调节剂的种类、质量浓度和喷施次数）3水平（植物生长调节剂分别为GA₃、PP₃₃₃和6-BA，植物生长调节剂质量浓度分别为100、200和300 mg·L^-1，植物生长调节剂喷施次数分别为1、2和3）叶面喷施实验，研究不同处理对薄壳山核桃品种‘波尼’枝条生长和叶片碳氮代谢物积累的影响。结果表明：GA₃处理组薄壳山核桃品种‘波尼’枝条长度较CK（对照，蒸馏水喷施3次）组显著增加，其中，T2（200 mg·L^-1 GA₃喷施2次）处理组的枝条长度最大，较CK组增加了35.7％；PP₃₃₃处理组的枝条粗度总体上较CK组显著增加，其中，T5（200 mg·L^-1 PP₃₃₃喷施1次）处理组的枝条粗度最大，较CK组增加了23.8％。处理后30～90 d，所有处理组薄壳山核桃品种‘波尼’枝条叶片中可溶性糖含量均呈逐渐升高的变化趋势，而叶片中淀粉和可溶性蛋白质含量以及C／N比总体上呈先升高后降低的变化趋势。PP₃₃₃和6-BA处理组叶片中可溶性糖、淀粉和可溶性蛋白质含量以及C／N比总体上显著高于CK组，其中，T5和T6（300 mg·L^-1 PP₃₃₃喷施2次）处理组对叶片中可溶性糖和淀粉含量以及C／N比的促进效果较佳，而T4（100 mg·L^-1 PP₃₃₃喷施3次）和T8（200 mg·L^-16-BA喷施3次）处理组对叶片中可溶性蛋白质含量的促进效果较佳。极差分析结果表明：植物生长调节剂种类对薄壳山核桃品种‘波尼’枝条长度、叶片中可溶性糖和淀粉含量以及叶片C／N比的影响最大，植物生长调节剂喷施次数对枝条粗度和叶片中可溶性蛋白质含量的影响最大。研究结果显示：叶面喷施200 mg·L^-1 GA₃对薄壳山核桃品种‘波尼’枝条伸长的促进效果最佳，喷施200 mg·L^-1PP₃₃₃对枝条增粗及叶片碳氮代谢物积累的促进效果最佳。

Taking 5-year-old young trees of Carya illinoinensis ‘Pawnee’ as experimental materials， foliar spraying experiment with three factors （including type， mass concentration， and spraying times of plant growth regulators） and three levels （plant growth regulators of GA₃， PP₃₃₃， and 6-BA， respectively； mass concentrations of plant growth regulators of 100， 200， and 300 mg·L^-1， respectively； spraying plant growth regulators once， twice, and thrice， respectively） was conducted according to L₉（3³） orthogonal experimental design to study the effects of different treatments on branch growth and leaf carbonnitrogen metabolite accumulation of C. illinoinensis ‘Pawnee’. The results show that branch length of C. illinoinensis ‘Pawnee’ in GA3 treatment groups increases significantly compared with that in CK （the control， spraying distilled water thrice） group， in which， branch length in T2 （spraying 200 mg·L^-1 GA₃ twice） treatment group is the largest， with an increase of 35.7％ compared with that in CK group； branch diameter in PP₃₃₃ treatment groups increases significantly compared with that in CK group in general， in which， branch diameter in T5 （spraying 200 mg·L^-1 PP₃₃₃ once） treatment group is the largest， with an increase of 23.8％ compared with that in CK group. During 30-90 d after treatment， soluble sugar content in leaves of branches of C. illinoinensis ‘Pawnee’ in all treatment groups shows a tendency to increase gradually， while contents of starch and soluble protein and C／N ratio in leaves show a tendency to first increase and then decrease in general. Contents of soluble sugar， starch and soluble protein and C／N ratio in leaves in PP₃₃₃ and 6-BA treatment groups are significantly higher than those in CK group in general， in which， T5 and T6 （spraying 300 mg·L^-1 PP₃₃₃ twice） treatment groups have good promotion effects on contents of soluble sugar and starch and C／N ratio in leaves, while T4 （spraying 100 mg·L^-1 PP₃₃₃ thrice） and T8 （spraying 200 mg·L^-1 6-BA thrice） treatment groups have good promotion effects on soluble protein content in leaves. The range analysis result shows that type of plant growth regulators has the greatest influence on branch length， contents of soluble sugar and starch in leaves， and C／N ratio of leaves of C. illinoinensis ‘Pawnee’， while spraying times of plant growth regulators do on branch diameter and soluble protein content in leaves. It is suggested that foliar spraying 200 mg·L^-1 GA₃ has the best promotion effect on elongation of branches， while spraying 200 mg·L^-1 PP₃₃₃ does on thickening of branches and accumulation of carbonnitrogen metabolite in leaves of C. illinoinensis ‘Pawnee’.