Took the main cultivated Fuji apples in Yanyuan County as the research object, six different planting densities were set up to analyze the effects of planting density on the growth of apple trees, photosynthetic characteristics, and fruit quality. The results showed that as the tree spacing increased, the indicators such as tree height, trunk diameter, canopy size, and new shoot length all significantly improved. Low-density planting was beneficial for alleviating tree competition and promoting overall growth potential. The analysis of photosynthetic characteristics indicated that the 1.8 m tree spacing had the optimal photosynthetic rate, and the higher-density treatments increased by 20.7%, and stomatal conductance and transpiration rate were also significantly improved. In terms of fruit quality, the single fruit weight of T₄ treatment reached 195.42 g, and the soluble solids, sugar-acid ratio, and hardness of the higher-density treatments increased by 9.3%, 22.5%, and 6.3% respectively, with the best overall performance.

apple  /  planting density  /  growth  /  photosynthetic characteristics  /  fruit quality  /  Yanyuan County