Effects of Different Paclobutrazol Concetration on Growth Characteristics,Yield and Volatile Oil Contents of Ligusticum jeholense

[Objective] The study aimed to improve the yield and quality of Ligusticum jeholense.[Method] The effects on the Ligusticum jeholense by different concentration of Paclobutrazol(100、200、300、400 mg/L) were studied,which including growth characteristics,yield,yield composing factors,and the contents of the volatile oil.[Result] The Paclobutrazol had an evident thick-dwarfing effect on Ligusticum jeholense,the treatment concentration of 400 mg/L had the most obvious effect,and better than that of 300 mg/L.With the increasing of the concentration of Paclobutrazol,the leaf area index and chlorophyll content of Ligusticum jeholense presented degrade tendency;the treatment concentration of 100 and 400 mg/L had the best effect to control the number of the flowers of Ligusticum jeholense.The treatment concentration from 100 mg/L to 300 mg/L could not only improve the yield,but also made a great help to accumulate volatile oil.[Conclusion] The Paclobutrazol concentration of 300 mg/L gave the help of Ligusticum jeholense growth and it could not only improve the yield,but also made a great help to accumulate volatile oil.