Abstract:
【Objective】 To investigate the effects of pulling on leaf size, chlorophyll content, photosynthetic parameters and fruit quality with the aim of screening the appropriate angle of pulling for high quality production of jujube.
【Methods】 Three levels of pulling treatments at 70°, 90° and 110° were carried out on the date head branches of the main stem-shaped jujube, with no pulling as the control, and then differences in leaf size, chlorophyll content, photosynthetic characteristics and fruit quality were analyzed at different pulling angles.
【Results】 The results showed that leaf size and chlorophyll content (
SPAD) were significantly higher in the pulling 90° treatment than in the control, and leaf area and chlorophyll content (
SPAD) were significantly higher in the pulling 70° and 110° treatments. The daily mean values of
Pn,
Gs and
Tr of leaves in the pulling 90° treatment were significantly higher than those in the pulling 70°, 110° and control, which were 13.36 μmol/(m
2·s), 0.36 mol/(m
2·s) and 10.29 mmol/(m
2·s), respectively, and the daily changes of
Pn,
Gs,
Ci and
Wue in the three pulling treatments and the control showed a bimodal curve. The average single fruit weight, soluble solids content, vitamin C content, and soluble sugar content were significantly higher in the treatments with a pulling angle of 90° than in the treatments with a pulling angle of 70°, 110°, and the control.
【Conclusion】 The suitable branch pulling angle of trunk Junzao is 90°, which is beneficial to the leaf growth, photosynthetic characteristics and fruit quality improvement of trunk Junzao.