Optimal Branch Bending Angle for Korla Fragrant Pear: A Multi-Trait Physiological Trade-Off Framework

Area of Science:

• Horticultural science
• Plant physiology
• Pomology

Background:

• Optimal branch bending angles for Pyrus sinkiangensis Yü (Korla fragrant pear) are not well-defined.
• Branch angle influences tree architecture, nutrient distribution, and fruit development.

Purpose of the Study:

• To determine the optimal branch bending angle for Korla fragrant pear.
• To integrate phenological, nutritional, hormonal, and fruit quality responses to bending angles.

Main Methods:

• Applied four branch angles (40°, 60°, 80°, 100°) to 8-year-old trees.
• Evaluated flowering dynamics, bud C/N status, leaf traits, shoot architecture, hormones, and fruit quality.
• Utilized principal component analysis (PCA) for trait integration.

Main Results:

• The 80° angle maximized fruit set (11.77%) and bud soluble sugar content (8.84 mg/g DW).
• Enhanced leaf area, chlorophyll, and mineral content (N/Mg/Cu) were observed at 80°.
• Optimal fruit quality (weight, sugar, sugar/acid ratio) and reduced stone cells occurred at 80°.
• PCA confirmed 80° as the system-wide optimum.

Conclusions:

• An 80° branch bending angle synchronizes carbohydrate supply, hormone signaling (GA4/GA7, IAA, zeatin), and fruit quality in Korla fragrant pear.
• This angle provides a low-cost, nonchemical strategy for precision canopy management in high-density orchards.
• Optimized carbon-hormone synergy at 80° maximizes fruit set and quality.