Influence of Promalin and different cutting back treatments on the branching character of 2-year-old apple seedlings | 普洛马林和不同短截处理对2年生苹果苗木分枝特性的影响

Chinese. 探讨普洛马林和不同短截处理对2年生苹果苗木分枝特性的影响，为促进具晚熟性芽的果树分枝及缩短果树童期和整形周期提供参考。以2年生苹果“长富2号”为研究对象，测定并分析主干不同短截处理（短截70，90 cm和不短截）和不同普洛马林处理（0和1 000 mg/kg）间分枝数目、分枝长度、分枝角度、分枝高度和分枝方位的差异。（1）1 000 mg/kg普洛马林处理可极显著增加不同年龄茎段的分枝总数。（2）普洛马林处理2年生苹果不同年龄茎段的分枝特性存在差异，普洛马林能够促进当年生新干（70 cm短截）再分生出新枝条，平均有效分枝数达4.1个，且分枝高度主要集中在90～130 cm，各方位的分枝数目接近1∶1∶1∶1，为整形工作带来了方便；普洛马林处理1年生老干（不短截）会造成分枝部位过低，极易导致分枝部位偏向一侧而致使中心干的地位不明显；普洛马林处理当年生新干和1年生老干（90 cm短截），能促进当年生枝条分枝，但1年生老干分枝的旺盛生长会抑制当年生新干的分枝。（3）群众育苗由于密度过大，自然状态下无有效分枝。对主干于70 cm处短截并用普洛马林处理，苹果树有效分枝的数目、长度、角度适中，分枝高度和方位合理，为其提早整形奠定了基础。

English. The research investigated the influence of Promalin and different cutting back treatments on the branching characters of 2-year-old apple trees in branching character, in order to provide reference for improving branching ability of late-maturing bud, shortening juvenile and shaping periods and so on. Choosing 2-year-old apple seedlings “Changfu 2” as objective, the branching numbers, branching length, branching angles, branching height and branching orientation in different cutting back (70 cm, 90 cm, no cutting back) and Promalin (0 and 100 mg/kg) treatments were counted and measured. (1) 1 000 mg/kg Promalin can significantly increase the branching number of different ages’ stem segments in total. (2) Difference existed in 2-year-old apple seeding different ages’ stem branching character after Promalin treatment: Current trunk after Promalin treatment (Seedling with 70 cm cutting back) could promote new branch, average effectual laterals’ number reached 4.1, and branching height mainly occured to 90-130 cm, the branch number in each orientation reached 1∶1∶1∶1, providing convenience for tree shaping; Annual branch after Promalin treatment (Seedling without cutting back treatment) would result in too low branch height, leading to one side branch so that the center of trunk wasn’t obvious; Both current and annual branch after Promalin treatment (Seedling with 90 cm cutting back) could promote current stem segment branching, while annual stem segment grew strongly, which would suppress the growth of current branching. (3) High density of mass breeding could not get effectual branching. In conclusion, with Promalin treatment after 70 cm cutting back, the suitable number, length and angle of effectual laterals of tree trunk were good. Meanwhile, appropriate branching height and orientation of effectual laterals could lay foundation for early shaping.