Early Selection of Superior Chinese Fir Clones based on Early Growth and Lateral Branch Development Characteristic

In 2024,a study was conducted on 11 clone trial plantations of Cunninghamia lanceolata established in 2019 at the Pushang State-Owned Forest Farm in Shunchang County, Fujian Province.The growth traits and lateral branch development characteristics at four years of age were investigated and analyzed, using seedlings from the second and third generation seed orchards of improved Cunninghamia lanceolata clones at the same forest farm as controls.The aim was to select superior clones suitable for cultivating knot-free timber.The results showed significant differences（P ＜ 0.05）in ground diameter, tree height, crown width, and lateral branch development among different clones.Yang 063 and Yang 061 exhibited significantly greater ground diameter, tree height and crown width compared to other clones and the controls, making them superior clones suitable for fast-growing and high-yield plantations.Yang 063 demonstrated substantial growth in ground diameter and tree height, along with long internodes between lateral branches, few lateral branches, and small lateral branch basal diameters, indicating its suitability for knot-free timber cultivation.Yang 020 was also relatively suitable for knot-free timber production.Associations were observed between growth traits and lateral branch characteristics among different clones: ground diameter was significantly positively correlated with lateral branch length, and internode length between lateral branches was significantly positively correlated with lateral branch basal diameter.