Study on the Cultivation Technique for Non-knot Timber of Cunninghamia lanceolata

The approach of cultivation for the target-tree was studied.The method which planting Chinese fir with non-knot timber by artificial pruning,could improved the timber value of Chinese fir in the southern market.To form a series of intact technique,reserve density and pruning intensity were identified as the factors in the test design.According to 4 years' observation,the analysis showed that:(1)the growth of Chinese fir had not been distinctly affected by different reserve density in the initial 8 years.At the range of 1 800 trees·hm-2,a denser reserve density could be setted;(2)The growth of Chinese fir would been distinctly affected by different pruning intensity.The stronger the pruning intensity,the lower the growth in the tree height,diameter breast height and crown width of Chinese fir would be.Considering the impact of pruning and the growth of Chinese fir,the pruning intensity of 10 cm was the best.