Relationship Between the Distribution of Relative Light Intensity and Fruit Quality of Trellis-trained ‘Hwangkumbae’

The relationship between the fruit quality and the relative light intensity,and the number of branches and leaves in trellis-trained‘Hwangkumbae’(Pyrus pyrifolia ‘Hwangkumbae’) was studied. The method of division in canopy was used to study the distribution of relative light intensity, and shoots and leaves, and fruit quality in different layers and positions of canopy. The results showed that the distribution of relative light intensity in the canopy gradually descended from upper to lower layer, and less 30% of the relative light intensity distributed mainly in the lowest layer of canopy. The branches (shoots) and fruitage were distributed mainly from 1.0 m to 2.0 m height of the canopy in uprightness. And the per fruit mass, firmness, soluble solid content were positively correlated to relative light intensity, whereas titratable acidity negatively correlated with it. The regression equations in relationships between quality factors and relative light intensity were set up and the obtained optimum relative light intensity was 42.17% for per fruit mass, 78.98% for soluble solid, 70.12% for firmness, 59.97% for titratable acidity, respectively. The regression equations in relationships between relative light intensity and types of branches (shoots) were set up and the obtained optimum proportion in shoot, meddle shoot and spur shoot were 2.61%, 6.59%, and 90.8%,and the total number of the shoots was 4.295×105·hm-2.