A general term for the structural shape of a fruit tree’s crown. The tree shape of fruit trees has two meanings: from the perspective of botanical characteristics, it refers to the shape of the tree crown in the natural growth state, also known as tree posture; the artificially shaped tree shape refers to the shape composed of the crown skeleton. The formation of tree shape depends on biological characteristics, such as branch angle, polarity, growth potential, branching power, germination power, softness and hardness of branches, etc. At the same time, the cultivation purpose, shaping method and rootstock should be considered (see fruit tree shaping and pruning).

During the investigation and research of fruit tree resources, the records of tree shapes in the natural state were mainly based on the geometric shapes of the tree crowns. Tree species and varieties with small branch angles, strong polarity, and strong growth potential often have relatively upright tree shapes, such as oblong, cylindrical, narrow cone, inverted cone, spindle, etc.; branches with large branch angles , tree species and varieties with weak polarity and soft branches mostly have an open tree shape, such as oblate, semicircular, and wide conical shapes; those with weak stemness, soft branches, large branch angles, and many branches are drooping or If they grow horizontally, the tree shape will be disordered and spread out; if multiple trunks sprout from the ground, the crown of the tree will often form a cluster shape. The shape of a tree in its natural state is representative in reflecting its biological characteristics.

The tree shape mentioned in fruit tree production is composed of certain backbone branches and branches forming a skeleton crown. A high-yielding tree should have the following characteristics: low trunk, short crown, few main branches, small side branches, open angles, and many branch groups with reasonable configuration (Figure 1).

Based on the biological characteristics of fruit trees, environmental conditions and cultivation purposes, the artificial natural shapes of fruit trees are divided into three types: central trunk shape, centerless trunk shape and creeping shape. Tree shapes with a central trunk mainly include scattered layered shape, two-layered open heart shape, cross shape, cone shape, deformed trunk shape, cylindrical shape, spindle shape, middle trunk and small crown shape, etc. Tree shapes without a central trunk mainly include cup shape, natural open heart shape, disc shape, three-legged shape, round head shape with multiple main branches, cluster shape, etc. The flat crowns that require supports include flat spindle-shaped, palm leaf-shaped, "V"-shaped, horizontal scaffolding-shaped, and fence-shaped (see shelf-shaped). The creeping shape is a special tree shape developed by fruit trees in cold areas to adapt to the need for burial in soil (see creeping cultivation). The main types of tree shapes are described as follows:

Figure 1 Scattered layered shape

It is also called the trunk sparse layered shape. It evolved from a conical crown and is a common tree shape for fruit trees with strong dryness such as apples and pears. It is also used on walnut, chestnut, persimmon, hawthorn and other fruit trees. The crown is semicircular or flat and short conical (Figure 2). It has a strong central trunk with 5-6 main branches, which are grown on the central trunk in three layers: 3 branches on the first layer, 1-2 main branches on the second layer, and 1 main branch on the third layer. The stem height is 50 to 60 centimeters, and the spacing between the first and second main branches is 80 to 100 centimeters, and 60 to 80 centimeters in mountainous areas. The angle between the planes of the three main branches on the first layer is about 120°; the opening angle is about 60°. There are 2 to 3 side branches growing randomly on both sides of each main branch. The opening angle of the main branches on the second and third layers is about 50°, staggered from the main branches on the first layer, and equipped with two side branches each. The main trunk is sparsely layered, forming quickly, bearing early, and yielding high yields. When the saplings are growing vigorously, central branches can be left above the third layer. When the tree crowns gradually connect during the fruiting period, they can be thinned out and gradually dropped to prevent the fruiting parts from being moved outwards in the later stage. For short-branched apple varieties, due to fewer branches and dwarfed tree shape, the main branches or side branches are actually equivalent to large fruiting branch groups, so 1 to 2 can be added to increase the number of branch groups and expand the fruiting area.

If the main branches are not divided into layers and are allowed to remain naturally selected, and the tree shape is higher, it will become conical or change into a trunk shape. The former is currently mostly used on tree species such as jujube, persimmon, ginkgo, walnut, torreya and olive, while the latter is partially used on apples and pears.

Natural open-ended shape

Referred to as "open-ended shape". It is improved on the basis of cup shape. The cup-shaped tree has the characteristics of good lighting conditions, short tree body and easy management, and avoids the cup-shaped mechanical shaping and heavy pruning. The standard tree shape is: the trunk is 30 to 50 cm high, with 2 to 4 (mostly 3) main branches staggered on the upper end of the trunk, extending diagonally to the surroundings, and 3 to 4 side branches growing in the anticlinal direction of each main branch. , the opening angle is 70° to 80°, and there are groups of branches on the side branches. The angles of the main branches can be different. The angle of the first main branch can be increased to 60°~70°, and the angle of the second and third main branches can be reduced to 40°~60°, so that the main branches and leaves can be staggered with each other and make full use of the space. You can choose to leave a small group of small branches on the back of the main branch diagonally into the crown to prevent sunburn on the backbone branches. Tree height is generally controlled within 3 meters. The open-shaped shape is easy to shape, quick to form, early to bear fruit, good lighting, and good fruit quality. The tree is short and easy to weaken, so attention should be paid to later support. It is suitable for peaches, plums, plums, etc. that like light and have weak stemness (Figure 3).

Figure 2

Figure 3 Two-layer open-ended shape

It is a tree shape between the evacuation layered shape and the open-ended shape. There are three ways to form it. : First, based on the open-angle or disc-shaped shape with a large opening angle, select the back branch of the main branch, cultivate it into a central trunk, and divide the second layer of main branches; the second is based on the sparse layer shape of the main trunk. On the top, thin out the central trunk above the second layer and the main branches on the third layer; third, start from the saplings, that is, cultivate them in a heart-shaped shape on the second layer. The second layer is open-shaped, with a stem height of 50-60 cm, 5 main branches, 3 on the first layer, with an opening angle of 60°-70°, and 2-3 side branches per main branch; 2 on the second layer, with an opening angle of 50°. ~60°, about 1 meter apart from the first layer, and staggered in direction, leaving 1 to 2 side branches on each side. It is suitable for some species with strong polarity and light-loving tree species.

Apple and peach trees can also be used (Figure 4).

Figure 4 The three-legged body shape

It is a transformation of the pear tree cultivation area in Qingdao City, Shandong Province based on the natural round head shape of the pear tree with multiple main branches, after sawing off the center trunk of the crown. The tree has a three-legged shape with three main branches growing diagonally upward to form the first-level skeleton of the canopy. The trunk is 40 to 50 centimeters high, the tree is 4 to 5 meters tall, and the crown is cylindrical. 3 The main branches grow diagonally upward from the trunk at an angle of 30° and are hollow. Each main branch branches out into 2 to 3 large branch groups. The first branch group has an opening angle of 80° to 90°, which is almost horizontal. The second and third branch groups have an opening angle of 60° to 80° and 50° to 70° respectively. , the distance between branch groups is 1.3~1.5 meters. Each large branch group in the lower layer then divides into 2 to 3 lateral branch groups, and the upper second-layer branch group divides into 1 to 2 lateral branch groups, resulting in a total of 15 to 20 lateral branch groups in the whole tree (Figure 5). Since the three large main branches grow upward in parallel, the tree's upward strength is alleviated, but it can maintain the tree's vigor for a long time, with a strong skeleton and good light transmission. It is suitable for Chinese pear varieties and has also been tried on apple and peach trees. In Qixia and Laiyang, Shandong, three diagonally growing main branches are left upward on the disk to form a straight disk shape, which expands the fruiting area and increases yield.

Figure 5 Natural round head shape

Also known as natural semicircle (Figure 6). After setting the stem, on the basis of allowing the upper end of the stem to grow naturally, select several large branches that open in four directions as the skeleton, and thin out the overly dense branches. The direction and angle of the main branches have no certain pattern, and there is no obvious layer. The crown shape is semicircular. The side branches and branch groups are inserted into the hollow distribution, the shape is natural and easy, and the fruit is early. However, for light-loving fruit trees, the interior of the crown is prone to early emptying, and the fruiting parts are often concentrated on the periphery of the crown. Before the introduction and promotion of Western plastic surgery technology in China, most fruit trees, such as red roses, pears, persimmons, hawthorns, chestnuts, walnuts, jujubes, apricots, citrus, longans, lychees, etc., mostly used this shape. Currently, many deciduous fruit trees are old and semi-cultivated. Trees, as well as evergreen fruit trees such as lychee, longan, citrus and other shade-tolerant fruit trees are still used.

The small crown shape of the trunk in Figure 6

The appearance of the crown is similar to the sparse layer shape of the trunk, but the trunk is short and the crown is small. There are also three main branches in the first layer and no side branches. The main branch is nearly horizontal, and 2 to 3 large branches are inserted into the space above it. The branches are directly branched. The general crown diameter is 2 to 3 meters, with a large bottom and a small top. The tree height is 2.5 to 3 meters. Due to the small crown and few backbone branches, the main branch is nearly horizontal. , the lighting conditions inside the crown are good and suitable for dense planting (Figure 7).

Figure 7 Cluster shape

The cluster shape is a tree shape with multiple main trunks growing diagonally from the ground. There are no obvious main branches, and auxiliary branches and branches grow directly on the main trunk. Branch group. The cluster shape can be branched from one plant, or 3 to 4 plants can be planted in one hole. It is widely used on fruit trees such as northern peaches, Chinese cherries, pomegranates, raspberries, and gooseberries. It is suitable for shrubs and dwarf fruit trees and has strong adaptability to adverse environmental conditions (Figure 8).

Figure 8 Cylindrical shape

Origined from the United Kingdom, it is an improved trunk shape that does not require supports and has no main branches. The branches are directly attached to the central trunk. The trunk height is 40-60 cm, the tree height is 2.5-3 meters, the crown is cylindrical, and the crown diameter is generally within 2 meters. The branch groups extend from the central trunk to the surroundings. The distance between branch groups is about 30 cm. There are about 30 to 35 branch groups in the whole tree. Each branch is combined with branches of different ages to rotate new shoots, fruiting branches, and fruiting branches (Figure 9). The cylindrical shape is simple to shape, and the crown receives good light conditions. When the plants are connected, it can also develop into a hedge shape.

Figure 9 Spindle shape

Origined from Germany and developed from the trunk shape. It is widely used in Nordic countries such as Germany and the Netherlands. It is between the trunk sparse lamellar shape and the cylindrical shape. In the middle, it is also a small crown shape with a medium stem. Its characteristics are that it has a central trunk and is relatively short. The main branches on the first layer and above are not strictly stratified, and the main branches are directly divided into branches. The main branch has a larger angle, smaller extension, and is larger at the bottom and smaller at the top. The spindle shape generally has a stem height of 30 to 35 cm, a tree height of 2.5 to 3 meters, and a crown diameter of less than 3 meters. The amount of pruning is small, which is in line with the natural growth habits of fruit trees. It bears early fruit and is suitable for pears, plums, dwarfs, and semi-dwarfs. Or short-branched apples. For rootstocks with poor soil stability or tree species and varieties with soft branches, pillars need to be erected (see fruit tree shaping).

Fence shape

Origined from France, it is a form of pruning relying on the wall. There is no main trunk, no obvious main branches and levels. The crown is flat but has a certain thickness (see fruit tree shaping). The trunk height is 30 to 40 cm. The branches on the trunk are pulled parallel to about 90°, and then some upright main branches are selected as needed to form diagonal shapes. The tree height is 2.8 to 3 meters, and the hedge wall thickness is 1.5 to 1.5 meters. 2 meters. This kind of tree shape does not need to have a support, and there is no fixed pattern for shaping. It is easier than the geometric fence shape, has early results, is easy to manage, and has low cost. However, after many years, the branches and leaves in the tree wall are easy to close. It is suitable for tree species and varieties with few long branches, many short branches, and low density of branches and leaves, such as some varieties of Japanese pears, or short-branched apples. After entering the fruiting stage, pay attention to thinning out the branches.

The palm leaf shape originated from France and is a special plastic surgery method that is highly artificial. Its basic structure is a vertical central trunk, or several central trunks, with main branches selected from left to right from the central trunk, and these branches are all on the same plane. This tree shape is different from the natural habit of fruit trees growing in all directions, so they are all bound by wire frames (Figure 10). According to the structure of the central trunk and main branches, it is divided into various tree shapes such as horizontal palm leaf shape, inclined palm leaf shape and V-shaped palm leaf shape.

The crown is thin and the light conditions are good, which can provide high-quality fruits, but the crown is small and the yield is low. It is used in southern Europe, Canada and the Soviet Union where the temperature is low and the growing season is short, such as apples, pears, peaches, sweet cherries, plums and other fruit trees. The trunk height is 30 to 40 cm, the tree height is 1.8 to 2.4 meters, 3 to 4 wires, the distance between wires is 30 to 60 cm, and 6 to 8 main branches are divided into 3 to 4 layers.

Figure 10 Natural Fan Shape

It is a tree shape similar to the palm leaf shape, but it does not have a support and the branches and leaves are distributed with a certain thickness, making it a very flat tree shape. The trunk is 30 meters high, with 3 to 4 layers of main branches, two of which extend at an angle of 15° to the row direction; the second layer of main branches is on the other side of the first layer of main branches, also at an angle of 15° to the row direction. Corner, the upper and lower main branches are staggered left and right, with a layer spacing of 50 to 100 cm. Branch groups are left on the main branches without leaving side branches. The whole tree is 2 to 3 meters high. When the plants are connected, they form a hedge shape (Figure 11).

Figure 11 V shape

A tree shape in which the main branches of a fruit tree grow in a V shape. Those with brackets are called V-frames. Originated in Australia, it has been used on peach, apple, pear and other fruit trees, and has also begun to be used in the United States and New Zealand. Two main branches sprout from the trunk, leaving no central trunk. The angle between the two main branches is 60°, and they grow diagonally upward at an angle of 60° to the ground. The spacing between the top branches is 2 meters, the tree height is 2.5 to 3 meters, and the crown width is About 2.5 meters (Figure 12). The V-shaped fruit bears early fruit, has high yield and excellent quality, and is convenient for manual and mechanical fruit thinning and harvesting.

Figure 12 "Peach Book" is a monograph describing the cultivation of peach in Shanghai during the Qing Dynasty. The author Chu Hua, whose courtesy name was Qiupe and whose name was Wenzhou, was a scholar in Shanghai during the Qianlong reign of the Qing Dynasty. The book was written in the 18th year of the Jiaqing reign of the Qing Dynasty (1813). Peach varieties have been recorded in documents from the 12th century, and were initially only cultivated in Zhejiang Province. In the late Ming Dynasty, they spread to Shanghai and became a famous product in the Luxiang Garden of the Xianguan family. In the Qing Dynasty, Shanghai has always been a famous peach-producing area. Peach seeds continued to spread to other places and were introduced to Britain, Japan and other countries. Since peaches were a famous product in Shanghai at that time, the author knew about them in detail and recorded the facts. The book is about 2,000 words long and is divided into sections to describe the history of peach cultivation in Shanghai, peach characteristics, propagation methods, cultivation and management techniques, etc.