Research On The Techniques Of Architecture Of Red Fuji Apple Trees On Dwarf Rootstock

The pruning and training techniques of young apple trees on dwarf rootstock, the tree structure parameters, the characteristics of canopy, the daily variation of sunlight, temperature and relative humidity, and the relative content of Chlorophyll in different parts of the canopy were researched with intensive planting Red Fuji young apple trees on dwarf rootstock, six-year-old and seven-year-old dwarfing and standard trees. In addition, the comparison of fruit quality in different parts of apple trees on dwarf rootstock and standard trees were studied as well. The main results were as follows:1. On the one hand, the length of leading branch on the top of central leader and the heading height of young apple trees on dwarf rootstock planted in the spring of that year was a negative correlation, and the correlation equation wasy=-0.00653x2+1.19169x+37.4887, correlation coefficient (R2) was 0.9290. On the other hand, the relationship of the length of leading branch and the cut diameter in the last year of the top of central leader was y=20.706e0.188x, and the correlation coefficient (R2) was 0.7991. Therefore, the suitable cut diameter was 8 mm to 9 mm. Besides, the total number of branches and the number of left main branches was a positive linear correlation, and the correlation equation was y=16.08679x-16.47437, correlation coefficient (R2) was 0.8043. When the number of left main branches was 20 per tree, the total number of branches was 299 which was the biggest. However, comparison to the other treatments, the trunk diameter, crown diameter and the length of leading branch on the top of central leader was no significant difference.2. The tree height was 385.8 m, crown diameter was 243.3 cm, spacing of between crowns was 106.7 cm, total number of branches was 1188 096 /hm2, the fruiting wood was 57354 m/hm2, and the ratio of short branches to medium branches to long branches was 81: 9: 10 when the trees on dwarf rootstock was six year old. As to the seven-year-old trees, the tree height was 423.3 m, crown diameter was 259.2 cm, spacing of between crowns was 90.8 cm, total number of branches was 1807848/hm2, and the ratio of short branches to medium branches to long branches was 68: 13: 19. And the main branches uniformly located on the central leader, the length of main branches, total number of branches, inflorescences, and fruit in different parts of the central leader gradually reduced from bottom to top. However, the changes of the rate of branch diameter to trunk diameter which showed an opposite trend were gradually increased from 0.29 to 0.52 mm. And the rate of branch diameter to trunk diameter did not change as the tree-age increased.3. The LAI and radiation interception rate at between rows of trees on dwarf rootstock were smaller than that at the trunk, 1/4 crown and in rows. The Proportion of Visible Sky, Indirect Site Factor, Direct Site Factor and Globle Site Factor at between rows were significantly higher than the other parts. The dynamic changes of canopy parameters of different parts showed a similar trend. Namely, the LAI and radiation interception rate rised in the early stage, and then decreased after pruning in summer, gradually rised again in later time, and began to reduce in coloring time of fruit. The trend of the Proportion of Visible Sky, Indirect Site Factor, Direct Site Factor and Globle Site Factor was opposite. The canopy parameters of 1/4 crown and in rows were highly influenced by pruning in summer.4. There were significant differences in the sunlight illuminating time in different orientation of 1/4 canopy of trees on dwarf rootstock. The illuminating time of the South was the longest, and the time was 8.5, 5.5 and 4.0 h at 280, 180 and 80 cm altitude to the ground respectively. To the contrary, the illuminating time of the North was the shortest, the time was 6.0, 3.0 and 2.5 h at 280, 180 and 80 cm altitude to the ground respectively. The illuminating time of the South and North was in the morning and afternoon, the East was mainly in the morning, and the West was mainly in the afternoon. There was only illuminating sunlight in the upper canopy at noon.5. The apple quality of different altitude of trees on the dwarf rootstock was no significant difference, but there was obvious difference in the standard trees. Especially, the soluble solid content of the apples bellow 180 cm of the standard tree was significantly lower than the parts above 180 cm, however, there were no significant differences in the apple tree on dwarf rootstock. Comparison to the standard tree, the soluble solid content, fruit index, titratable acid content and the finish index of the tree on dwarf rootstock were all higher than that of the standard tree, the single fruit weight, surface index and the firmness were no significant differences.