Growth Traits and Growth Rhythm of Melia azedarach Seedlings from Different Provenances

The growth traits of Melia azedarach seedlings from ten provenances were observed,and the growth rhythm of seedling height,ground diameters and crown width were analyzed by using the growth parameters simulated from the Logistic model. The results showed that the growth rhythm showed“Stype”curve. The determination coefficient varied from 0969 to 0998.There were significant differences in seedling height, basal diameter and canopy breadth among different provenances, the early growth was less than that in the later.The starting time of fastgrowing period of different provenances changed from May to June, the earliest differed by 20d from the latest one.The end time of fastgrowing period changed in August to October there were about 50 d difference between the earliest and the longest provenance.In the fastgrowing period, the growth accounted for the total growth in more than 58%. The provenance with the biggest growth amount in fastgrowing period was about 2 times of the smallest provenance. There were no significant differences between ground diameters and crown width, and they started earlier than seedling height in the starting time of fastgrowing period. The finish time of fastgrowing period of crown width was earliest, and then was height and ground diameter. In general, the provenances from the northern were earlier than the ones from the southern in the starting time of fastgrowing period, but were later in the ending time of fastgrowing period.