Effects of Tree Shape Adjustment on Flower Formation and Fruit Setting of Torreya grandis cv. Merrillii

[ Objective] In this study, the number and opening angle adjustment of Torreya grandis cv. Merrillii skeleton branches were performed in order to explore their effects on the formation of mixed bud and fruit setting, so as to provide a scientific basis for tree cultivation of T. grandis cv. Merrillii young forest and to promote early fruiting and high yield.[Method]Single factor and interactive experiments with the number and opening angle of skeleton branches were conducted to investigate the development of flowers and fruits, proportion of mixed buds, and fruit setting rate. Light intensity, endogenous hormone content, photosynthetic carbon assimilate content, carbon nitrogen ratio and other indicators were determined.[Result]The number adjustment of skeleton branches had a great effect on the light transmission ability, and 3 skeleton branches(N3) and 4 skeleton branches(N4) significantly increased the light intensity in the central and lower layers of T. grandis cv.Merrillii canopy, which was conducive to