Annual Height Growth Laws of Saplings from Cuttings of Some Poplar Clones

On the basis of data analysis derived from field investigation, a simulation research on height growth law of one -year saplings from cuttings of 7 poplar strains including No.107 Popular euramericana was conducted by means of Logistic equation.The results showed:The annual growth trends of the 7 poplar strains saplings could be well demonstrated by Logistic equation, and the relevant coefficient exceeded 0.99.The growth phase of the cutting saplings could be divided into 3 stages, i.e., the pre -growing stage, the fast -growing stage, and the post -growing stage.The largest daily growth appeared around the 118^rd days after the cuttage was done, and the fast -growing stage appeared between the 93^rd and the 143^rd days, which lasted for about 50 days, accounting for 24% of the whole growth period.However, the growth quantity during the fast -growing stage was about 58% of the annual growth quantity.The results corresponded with the production situation, which might provide theoretical base for the production and management of poplar cuttings.