1. 14-year-old off-year bayberry (Myrica rubra Bieb.et Zucc) trees of 'Biji' cultivar from Yuyao were used to determine the changes of nucleic acid, IAA, proteins, lignin, carbohydrate, calcium and tryptophane, and the activities of nucleic acid hydrolases, IAA oxidase, lignin synthase, amylase and acid invertase in leaves of new shoots after GA3 spray during flower bud physiological differentiation and initiation in 1999. The results showed that flower bud physiological differentiation is in Jul...