The pear tree consists of underground and aboveground parts. The underground part is called root system, and the aboveground part is called crown. The spatial distribution and arrangement of various main branches and fruiting branches in the crown is called tree structure.
Trunk: The part from the root neck to the first branch is called "trunk", also called "trunk".
Crown: The whole part of a tree above the trunk. The crown consists of various branches, which are divided into central main branch, main branch, lateral branch, developing branch and fruiting branch.
Central trunk: the trunk branch above the trunk that grows upright in the center of the crown, also known as "central trunk" and "central main branch".
Main branch: a large branch branched from the trunk of the central leadership, which is the main skeleton of the crown.
Side branches: Branches that are separated from the main branch in a better position and grow weaker than the main branch are called "side branches".
Trunk branch: referred to as branch for short, it is a thick and shaped branch that plays a role in skeleton load in the crown. Including trunk, central trunk, main branch, side branch, etc.
Auxiliary branches: Branches that are separated from the main branches and used as temporary supplementary space to support trees to increase production are called "auxiliary branches".
Competitive branches: after the second bud germinates under the incision, it often grows more vigorously or almost as long as the branches formed after the first bud germinates. Such a branch is called a "competitive branch".
Fruiting branch group: referred to as branch group for short, it is a unit branch group distributed on backbone branches at all levels and directly flowering and fruiting in turn. Generally, it consists of fruiting branches and vegetative branches with multi-level branches on the same mother branch.
Crown skeleton structure
Names and locations of non-backbone branches
(2) Types and characteristics of branches and buds
(2) Types and characteristics of branches and buds
1. branch bud species (1) The buds of pear trees are late-maturing buds, which generally do not germinate in the same year, but sprout new branches in the next year, with few secondary branches. Buds of pear trees can be divided into two categories, namely leaf buds and flower buds.
(1) Leaf bud. Buds that can only produce branches and leaves after germination are called leaf buds, excluding flower organs. Leaf buds are attached to the top and side of branches.
tender leaf
2 buds. Buds containing floral organs are called flower buds. The flower buds of pears are mixed buds, which can sprout branches and grow leaves, but also blossom and bear fruit. Flower buds are divided into terminal flower buds and axillary flower buds, and pears mainly bear fruit from terminal flower buds. The axillary buds can also be used to bear fruit in the young tree stage to increase the yield, but the axillary buds bear small fruit and poor quality.
blossom bud
③ Latent buds and secondary buds. Latent buds are mostly accessory buds, attached to both sides of the main buds, which are extremely small and difficult to see with the naked eye. Because it does not germinate, it is hidden on both sides of the branch base after many years. This kind of bud can only grow branches when it is strongly stimulated.
Accessory bud on one side of branch base
(2) Branching of pear is formed by leaf bud germination. In order to facilitate the management in production, branches are generally divided into vegetative branches and fruiting branches according to their growth and fruiting habits.
① vegetative branches. Branches without flower buds. Nutritional branches can be divided into short branches, middle branches, long branches and long branches (referring to branches with long internodes, small buds and insufficient growth). Generally, short branches are shorter than 5 cm, middle branches are longer than 5 ~ 15 cm, and long branches are longer than 15 cm.
② Fruiting branches. Branches with flower buds are called fruiting branches, which can blossom and bear fruit. Fruit branches can be divided into short fruit branches, middle fruit branches, long fruit branches and axillary flower bud branches. The length of short fruit branches is below 5 cm, the middle fruit branches are 5 ~ 15 cm, and the long fruit branches are above 15 cm.
2. Growth characteristics of branches and buds
(1) Branching power and germination power Branching power refers to the ability of buds on annual branches to grow branches, and germination power refers to the germination ability of buds on annual branches.
The branching ability of the same variety is strong in the young tree stage, but weak in the adult and aging stages.
(2) Heterogeneity of buds The quality of buds, that is, the size and fullness of buds, is different on a tree or a branch. This difference is called "heterogeneity of buds".
The heterogeneity of pear buds is not obvious. On the 1 branch, there are relatively full buds except for 2 ~ 3 blind nodes (no buds) at the base and 2 ~ 3 weak buds upward.
The expression degree of branching ability and germination ability: strong branching ability, strong germination ability, weak branching ability, weak branching ability and weak germination ability. The variety Jinfeng Lijing Pak Lei Li Xuehua Zaosu pear is the most sensitive and insensitive to the pruning reaction of the 20th century pear with abundant water and good luck. Branching age 1, branching is not short, and germination ability is not short.
attached table
Branching ability of the same variety at different ages
Heterogeneity of buds
(3) plumpness of buds
Plumpness of bud
(4) drying and layering of hair branches
Dry: Fruit trees form their own dry stems and maintain the characteristics of priority and vigorous growth and development.
Stratification: Due to the top advantage, the branches on the crown grow for many years to form stratification. This phenomenon is called "stratification". The formation of stratification is related to the interaction of apical dominance, bud heterogeneity, germination rate and branching ability.
Natural stratification (the central trunk is not cut) and artificial stratification (the central trunk is cut every year)
(5) Top advantage refers to the phenomenon that the growth potential of branches sprouting at or near the top of branches is the strongest, while the growth potential of downward sprouting branches decreases in turn. The more upright the branches are, the more obvious the apical dominance phenomenon is. The apical dominance of erect branches, oblique branches, horizontal branches and drooping branches decreased in turn. The growth of branches can be regulated by using the apical advantage.
(6) Germination of latent buds The latent buds of pear trees have a long life span, which can reach several decades. It can be used to update branches during pruning.
(7) Transformation ability of branches
Highest dominant expression form
dormant bud
Long branches can be transformed into more short and medium branches.
Medium and short branches are transformed into long branches.
Branches can form more short branches when they grow for a long time in a year. When the mother branch is stimulated by heavy shearing or injury, the short branches and middle branches on the branches can be transformed into long branches.
(8) The taper of trunk branches refers to the degree of thickness change from the base to the top. The degree of tapering is related to the firmness and bearing capacity of branches.
Note: ↑ indicates the flow direction and flow rate of water and nutrients.
(3) the characteristics of the results
One year, the branches grew and grew, and then they became flowers.
Results of the second year
1. Flower buds are easy to form and bear fruit earlier.
Most pear varieties are easy to form flower buds, such as Yali pear, Xuehua pear and Dangshan crisp pear. Annual development branches bloom in the same year and bear fruit in the second year. Most short branches bloom in the same year and bear fruit in the second year.
2. Fruit branch type
Pear trees mainly bear short fruit branches, and some varieties (such as Yali pear) are easy to form short fruit branches.
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3. Continuous result ability
Most varieties have strong ability to bear fruit continuously, and a few varieties bear fruit every other year.
Continuous fruiting ability of short branches
(4) Foundation pruning
1. Variety characteristics
Different pear varieties have great differences in branching ability, germination ability and branching angle. For varieties with weak branching ability and large angle, the first bud branch can be cut off as an extension branch of the main side branch; For varieties with strong branching ability and small angle, the third bud branch can be used as the main branch extension branch.
Pruning varieties with large branching angle, weak branching ability and strong germination ability
Pruning varieties with small branching angle, strong branching ability and strong germination ability
2. Tree age
In the young tree stage, the vegetative growth is vigorous, so pruning adopts light cutting and long planting of culture branches, and makes full use of auxiliary culture branches to realize early high yield.
Young tree stage
When pruning trees in full fruit, we should pay attention to the relationship between growth and fruiting, adjust the branches to prevent the branches from weakening, and keep the trees in a three-dimensional fruiting state, with high yield year after year.
Full fruit period
In the aging stage, trees are mainly rejuvenated, and branches germinated at the base of branches are fully utilized to cultivate branches and prolong the fruiting life.
Maturing period
3. Growth potential
When the growth potential is strong, slow pruning should be taken to make the moderate branches open at an appropriate angle to keep the growth potential moderate and robust; When the growth potential is weak, we should take rejuvenation and pruning, remove weakness and maintain strength, remove inclination and keep straight, and retract appropriately.
Branches with strong growth potential
Branches with weak growth potential
4. Natural conditions and management level
Mountain pear orchards have poor soil, insufficient fertilizer and water, weak trees and short plants. Trees with small crown and short stems should be used, with heavier pruning, more short nodes and less sparse gaps, and attention should be paid to rejuvenating the trees. On the contrary, in the plain pear orchard with fertile soil and abundant fertilizer and water, the plants grow vigorously, with a large number of plants and a large crown. The drying time is slightly longer, the head can be happy in the later period, and the pruning should be light. To control the tree potential, we should take the measure of "topping the crown with fruit".
Well-managed trees on the plain
Extensive management of mountains, hills and forests
5. Planting density
Sparse pear orchards mostly adopt tree trunk sparse layer shape, three forest shape and cross shape.
Close-planted pear orchards mostly adopt high heart shape, natural cone shape, spindle shape and so on.
Rare botanical garden
Dense planting garden
(5) the principle of pruning
1. is consistent with the growth and fruiting characteristics of pear trees.
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2. Adapt to local soil and climate conditions
3. Reduce the pruning cost