Effects Of Branch Angle On Growth And Fruiting Of Korla Fragrant Pear

In this study,Korla fragrant pear was used as the research material.During the growth period,the branches with basically the same height,orientation and growth potential on the test tree were selected for40°,60°,80°,100°,and 4 different angles of branch pulling treatment.Four different angles of branch pulling treatments were used to determine the flowering phenology,flower formation rate,fruit setting rate and calyx removal rate of Korla fragrant pear;bud nutrient content;leaf quality,chlorophyll content,mineral element content,leaf photosynthetic fluorescence parameters;fruit Appearance and internal quality were measured and analyzed,in order to explore the effects of different branch pulling angles on the regulation of flowering period,bud nutrient content,leaf quality,branch growth and fruit quality of Korla fragrant pear trees,and to establish the most suitable Korla fragrant pear pulling.The branch angle provides theoretical reference and guidance for the cultivation and shaping of Korla fragrant pear saplings.The research results are as follows:（1）Branch pulling had little effect on the flowering phenology of Korla fragrant pear.After Korla fragrant pears were pulled,the flower formation rate increased with the increase of the angle of pulling branches.When the angle of pulling branches was 100°,the flower formation rate reached a maximum of7.89%;the fruit rate at the angle of pulling branches was The maximum value was 9.41%at 40°;the fruit setting rate reached the maximum value of 11.77%when the branch pulling angle was 80°.The calyx removal rate gradually decreased between 60°and 100°,and the maximum calyx removal rate was 73.33%at 60°branching angle,which was significantly higher than the other three treatments.The content of nutrients in the buds was also affected by the branch pulling.The content of nutrients in the buds will be affected by the pulling,and the soluble sugar content and nitrogen content in the buds are the highest when the pulling angle is 80°.（2）The single leaf dry and fresh weight,leaf length,leaf width,leaf area,chlorophyll content,chlorophyll SPAD value,leaf N,Mg,and Cu content of three mineral elements of leaves all presented with the increase of branch pulling angle.The trend of increasing first and then decreasing is the largest when the branch pulling angle is 80°.The contents of two mineral elements,Fe and Zn,were the largest when the branching angle was 60°,and the Ca content was the largest when the branching angle was100°.Photosynthetic parameters of Korla fragrant pear at 80°branching angle were higher than the other three treatments,and the daily average values of P_n,C_iand T_rwere significantly different from other treatments.The daily mean values of C_NPQand R_ETwere the highest.At 80°,Korla fragrant pear had the strongest photosynthesis,weaker photoinhibition,and the best leaf development and physiological function.（3）Pulling branches can ease the growth potential and balance the competition and contradiction between vegetative growth and reproductive growth.Compared with 40°,60°,80°,and 100°increased the proportion of medium fruiting branches and short fruiting branches,while the proportion of long fruiting branches decreased.The length of medium and short fruiting branches was also inhibited,and the branch length decreased.Under the 80°treatment,the comprehensive growth of the thickness of long,medium and short branches was higher than that of the other three treatments.When the branch pulling angle was 80°and 100°,the water content of the branches was less,which was beneficial to the accumulation of nutrients.The total nitrogen content of the branches was the smallest when the branch pulling angle was 100°.（4）In terms of the external quality of the fruit,The 80°has the highest single fruit weight,the best fruit shape index,good stalk performance,better channel for transporting nutrients,smooth appearance,good color and less damage.In terms of the internal quality of the fruit,the 80°branching angle also performed better,the soluble solids were higher,the total soluble sugar content was the highest,and the stone cell content was the least.To sum up,branch pulling has a significant impact on the growth and fruiting of Korla fragrant pear saplings.When the branch angle of 80°is used for Korla fragrant pear saplings,the development of buds and flower bud differentiation are good,and the physiological functions of leaves are the best.It has high photosynthetic efficiency,reasonable branch composition and good fruit quality.Therefore,the 80°angle of pulling branches is the best angle for the plastic cultivation of Korla fragrant pear saplings.