Effects of Different Cut Height and Paclobutrazol Concentration on Dwarfing Control of Zelkova schneideriana Seedlings

Using 1.5-year-old Zelkova schneideriana seedlings as experimental material, this study investigated the effects of different trunk height treatments (2, 6, 10 cm) and paclobutrazol concentrations (0, 250, 500,750, 1000 mg/L) on dwarfing effects. Results showed that under identical trunk height conditions, increased paclobutrazol concentration significantly inhibited plant height, shoot thickness, and internode spacing in seedlings, demonstrating notable dwarfing effects. Additionally, chlorophyll, soluble protein, soluble sugar, and SOD levels initially increased, then declined as paclobutrazol concentration rose, with all treatment groups exceeding control values. MDA content, however, continued to rise as paclobutrazol concentration increased. Considering the growth characteristics and ornamental value of Z. schneideriana seedlings, a comprehensive analysis indicated that applying a 500 mg/L paclobutrazol solution combined with a 6 cm trunk height treatment achieved optimal dwarfing control while maintaining plant vitality.