Its characteristic is that there is a gap between rows, and the groups in rows are strengthened, forming a continuous thin vertical leaf curtain, which makes the light penetrate more and distribute evenly, which is beneficial to the improvement of yield and quality and crown management. Hedge wall shape can be divided into hedge shape and frame hedge shape according to whether there is support or not.
(1) Hedge modeling: This modeling refers to the tree shape that does not need the assistance of columns and mullions for crown modeling and pruning. Hedge width is generally controlled at around1.5m. ..
Natural hedge modeling: this modeling allows the crown to develop naturally, without pruning, but leveling the big branches and placing them in space. It is characterized by light pruning, early flowering and early fruiting. However, due to the chaotic distribution of branches, the yield in the middle and late stages was affected. This tree shape is often used when mechanized hedge shears or top shears are used abroad.
Flat spindle shape: This shape is a variation of three-dimensional spindle shape. The main branches of 1 ~ 2 layers are arranged in the middle and lower part of the central trunk, and the spacing between layers is about 80 cm. Each layer has two branches, which are opposite to each other and develop along a straight line. Leave two symmetrical and balanced side branches on each main branch, or the bottom is big and the top is small. All other branches in the middle and upper part of the central trunk are flattened along the row direction, forming various fruiting branches.
Straight trunk sector: The structure of this shape is that the central trunk extends straight, on which three layers of main branches are cultivated, and each layer has two opposite branches, which extend along the direction. The interlayer spacing is 60-80 cm, and the interlayer spacing 10- 15 cm decreases from bottom to top. Each main branch cultivates two symmetrical and balanced side branches, which are still large at the bottom and small at the top. Attention should be paid to the cultivation of auxiliary fruiting branches between upper and lower main branches. Mainly suitable for varieties with weak dryness.
Curved trunk sector: the basic structure of this shape is similar to that of straight trunk sector, except that the central trunk and main branches are required to bend and extend at an angle of about15. When the central trunk is bent, it should be bent to the left and right in the direction between plants, and the main branches should be thrown to the outside once a year. The whole tree has 4 ~ 6 main branches. When the main branch is bent, it should be bent forward from left to right, and it is also required to throw a small side branch or fruiting branch group outside the bent part every year. After the crown is formed, it can be thrown or dropped. Therefore, the main and lateral distribution of this shape is not layered, and its main feature is that it can effectively control the upper strength and the lower weakness, which is suitable for rootstocks and varieties with strong dryness.
Folding fan: this shape is a tree with a bent central trunk and no bent main branches. Each main branch is transformed from the original head of the central trunk, sometimes lateral branches are cultivated on it, sometimes lateral branches are not cultivated, and small and medium-sized fruit branches are directly distributed. In plastic surgery, seedlings are first required to be planted obliquely in the opposite direction to the grafting site, at an angle of about 45 degrees from the ground. In the germination stage of spring, the seedling trunk is continuously pulled into a horizontal state, forming the first bow, 40 ~ 50 cm from the ground. In order to ensure that the ideal strong branch is a new central stem above the bending part, the buds can be cut at the predetermined position, and the new buds sprouted at other parts should be controlled in time, such as twisting, taking, pulling and coring. In the second year, the newly cultivated central trunk bends in the opposite direction in the same way, forming a second bow, which is 80 ~ 100 cm from the ground. After that, it will be raised by one layer every year, forming an arch in the opposite direction to the previous year, with a vertical spacing of 40 ~ 50 cm. In this way, 2 ~ 3 main branches are cultivated on each side, and the spacing between overlapping main branches on the same side can be maintained at 80 ~ 100 cm. The height of the tree is 2.5 ~ 2.8 meters, and the anterograde branch is about 2.5 meters, which takes 5 ~ 7 years to form. Therefore, this shape can also effectively control the phenomenon of strong top and weak bottom, which is suitable for dry varieties.
Branch shape: also known as non-backbone shape, it is a simplified tree shape tried abroad to adapt to the mechanized pruning and harvesting operation of ultra-close planting grassland orchard. At present, there is no trial in China, even abroad. The planting density of this shape can be as high as 4700 ~ 6667 plants per 667 meters, and the plant spacing is 0.2 ~ 0.4 meters. The specific crown control pruning and its related management techniques will be introduced in detail in the fourth part "High-tech pruning technology".