| The selection of apple tree shape was very important and excellent shaping and pruning played an essential role in production of high quality fruit.The out-of-date dwarf apple close planting's excessive management cost and unsuitable for mechanical work with slender spindle apple trees.In the end of last century, the western developed countries with apple production prompt high-spindle apple trees, a novel tree shape adjust to fruit orchard with close planting of short stock. Presently, high-spindle apple trees have been in wide popularization and application in Italy and USA, but at the stage of introduction and demonstration in China.In this reach,10～11 years old'Liquan Fuji'high-spindle apple trees were used as experimental materials, and the canopy was divided into inner and outer horizontally, as well as top, middle and bottom vertically. The number of shoots and the leaf photosynthetic character, structural characteristics of tree, fruit yield and quality in different part of canopy were measured; The difference of structure, fruit quality and yield were investigated with the experimental material of 9-10 years old high-spindle apple trees under 4 different cultivation models of spur Fuji on dwarfing rootstock, spur Fuji on seedling rootstock, Fuji on dwarfing rootstock, Fuji on seedling rootstock; The 3, 6 ,9, 11 years old high-spindle apple trees were used as experimental materials, whose parameters of branch number, tree body structure, fruit quantity and yield were measured. The main conclusions obtained were as follows:1. Research on structure, yield and fruit quality of high-spindle apple trees in different canopyThe number of boughs increases from bottom to top, but the length, size, angle of boughs decrease gradually; Total shoots were 1 100 000 /hm2, the ratio of long shoots, medium shoots and spur shoots'number was 1:1:8; The difference of net photosynthetic rate of outer leaves was not significant, apparently higher than the inner leaf whose net photosynthetic rate decreases from top to bottom;The gradual increase of canopy volume and leaf density but the gradual decrease of DIFN from top to bottom.The yield of centre and bottom of the canopy does not differ greatly and was significantly higher than the top, it was higher by 25.3% and 32.7% individually.Fruit quality in different part of the canopy is good and the difference was not apparent, the mean fruit mass was 263.3～289.2g, fruit index was 0.86～0.89, fruit firmness was 8.98～9.53 kg·cm-2, surface blush was almost above 90%, soluble solid above14.6% and up to 15.8% at most, titratable acidity was 0.29～0.31%.All in all, the characters of high-spindle apple trees were short canopy, convenient administration, high yield and even distribution in the canopy, good fruit quality and so on. .So it is worth to be in popularization.2. Research on structure, yield and fruit quality of high-spindle apple trees under various scion/rootstock combinationsFor the 4 scion/rootstock combinations, number of boughs was 34～39, width of boughs was 21.6～25.0mm, height of stems was 82.2～90.0mm. For stem circumference, canopy diameter, canopy volume and leaf density, Fuji on seedling rootstock was at the peak, followed by spur Fuji on seedling rootstock and Fuji on dwarfing rootstock, then came spur Fuji on dwarfing rootstock.The ratio of long branches taken up 10 to 30 percent and short branches with more than 70 percent under all the 4 different models. Total branch number were all at large amount, spur Fuji on seedling rootstock reached 1,590,000 branches per hm2.Inner leaf net photosynthetic rate and DIFN showed the same trend: spur Fuji on dwarfing rootstock﹥spur Fuji on seedling rootstock﹥Fuji on dwarfing rootstock﹥Fuji on seedling rootstock.The yields of 4 scion/rootstock combinations were between 33.4kg and 35.0 kg, and each canopy volume were from 4.0kg to 5.4kg.Spur Fuji on dwarfing rootstock was more than spur Fuji on seedling rootstock, spur Fuji on seedling rootstock and Fuji on seedling rootstock at 16.7%, 20.4%, 25.9%. For each scion/rootstock combination, the quality of external parts has superiority over inner ones. Equally, fruit quality of dwarfing rootstock was superior vigorous rootstock.3. Research on the structure, yield of high-spindle apple trees in different agesStem circumference, canopy diameter, canopy volume and leaf density increased and DIFN decreased with the wax of age.Each age group had a small proportion of middle and long branches but a large proportion of short branches. The 3 years old apple trees had a large proportion of long branches and small proportion of short branches with comparison to the 6, 9, 11 years old trees. The different proportion of various branches was not significant. Total branch number of 3, 6, 9, 11 years old trees were 280725, 877800, 1194150, 1104375 branches per hm2.The yield of 3, 6, 9, 11 years old trees were 5760, 25800, 56220, 57645 Kg per hm2. It showed that yield improved dramatically with the increase of age at the early stage of fruiting and maintained a stable level at maximum period of fruiting. |
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