Effect of Applying Paclobutrazol Method on Growth and Development,Blossom and Fruiting of Starkimson Young Saplings

Objective The study was conducted to solve the problems appeared in Starkimson young trees,such as strong nutrient growth,the branches in corona erecting easily,late going into full fruit period and taking much time and labour in tree management by normal method.Method Effects of paclobutrazol used by spraying and burying in soil on growth,development,flower bud differentiation of young trees and per plant yield of Starkimson young trees were studied with 4 treatments as Ⅰ spaying paclobutrazol 1 500 mg/kg,Ⅱ burying paclobutrazol in soil 1.5 g/hole,Ⅲburying paclobutrazol in soil 1.8 g/hole andⅣburying paclobutrazol in soil 2.2 g/hole.Result Stem width growth presented a degressive trend as consumption of paclobutrazol increased.The growth increments in Ⅰ,Ⅱ,Ⅲand Ⅳ decreased by 45.97 %,37.39 %,48.64 % and 61.47 % respectively in first year and 18.64 %,32.03 %,55.15 % and 59.93 % respectively in the second year than those in CK.The capping time of apical buds of spring shoots in every treatment was 7~13 days earlier than that in CK.Average yield per tree and single fruit weight had significant difference among different treatments.Conclusion Paclobutrazol could restrain nutrient growth and promote reproductive growth of Starkimson young trees effectively and the Ⅱwith burying had best effect.