CN115024105A

CN115024105A - Method for whole-crown lower branch-supplementing, optimizing, updating and transforming chestnut tree

Info

Publication number: CN115024105A
Application number: CN202210635017.9A
Authority: CN
Inventors: 王东晨; 荣艳菊; 孙源蔚; 郭聪聪; 商贺利; 李文阁; 李泓; 施丽丽; 于海燕; 吴海生
Original assignee: Hebei Forestry And Grassland Technology Extension Station
Current assignee: Hebei Forestry And Grassland Technology Extension Station
Priority date: 2022-06-06
Filing date: 2022-06-06
Publication date: 2022-09-09

Abstract

The invention relates to the technical field of fruit tree management, in particular to a method for replacing excellent branches of chestnut trees under the full crown, which is characterized in that a trunk grafting part selected as a stock is circularly cut for a circle to form a circular cut wound under the full crown state of the chestnut trees, and then a good variety fruiting parent branch or a vegetative branch which grows robustly and has no diseases and insect pests is accessed by adopting a bark-inserting abdominal grafting method, wherein the circular cut wound can effectively prevent the nutrient transmission of the trunk branch, so that the nutrient is intercepted and enriched to the circular cut wound part in a short time, and the repair of a grafting port and the sprouting growth of a scion are promoted. As the main branch serving as the stock is not cut to be dry in the current year, the girdling wound can be healed quickly, and the fruiting quantity of the main branch of the stock is not affected basically, the method does not affect the fruiting quantity of the grafting in the current year, realizes the updating of the inner bore branch supplement under the conditions of no yield reduction, little yield reduction, no reduction or little income reduction, and solves the problem of bore baldness.

Description

Method for whole-crown lower branch-supplementing, optimizing, updating and transforming chestnut tree

Technical Field

The invention relates to the technical field of fruit tree management, in particular to a method for updating and transforming full-crown lower branch-supplementing and excellent-changing of a chestnut tree.

Background

In recent years, because a chestnut garden is sparsely managed or is not managed in place, chestnut trees grow upwards in an annual way and greatly expand crowns, and light cannot irradiate the inner parts and the lower parts of the crowns, so that baldness/vacuity of inner cavities of the chestnut trees and fruiting parts move outwards, further the yield of the chestnuts is reduced year by year, the benefit is poor, the management is difficult, and the like. At present, most chestnut gardens can promote the sprouting of chestnut tree bore branches through technical measures such as production-carrying grafting and the like, and although the problems of baldness in the chestnut tree bore, low yield and the like can be solved after 1-2 years, the yield of the chestnut tree in the same year is further greatly reduced due to grafting operation and the like, so that the income of chestnut farmers is influenced. The chestnut variety is changed into inferior and superior by adopting grafting methods such as grafting with yield or top grafting and the like, which can also cause the problems of reduced or no yield of the chestnut tree in the current year, the original yield can be recovered after 2-3 years, the yield of the chestnut tree is reduced in the period, the cultivation benefit is reduced, the economic benefit is deteriorated, the management and investment are limited, and poor circulation is formed.

Disclosure of Invention

Technical problem to be solved

In view of the defects and shortcomings of the prior art, the invention provides a method for updating and transforming chestnut tree full-crown lower branch supplementing and excellent changing, which promotes the updating of inner bore branch groups and variety changing and excellent changing of chestnut trees, solves the technical problem of low yield in the current year or no yield in the current year due to the grafting of chestnut trees by technical means, maintains the benefit of chestnut farmers in the current year of branch supplementing and excellent changing of chestnut trees as much as possible, improves the enthusiasm of chestnut farmers in branch supplementing and excellent changing of chestnut gardens, and realizes the virtuous cycle of management-benefit.

After the method is used in production, the chestnut trees can achieve the purposes of no yield reduction, little yield reduction, stable yield in the 2 nd year, high yield, variety upgrading and quality changing through grafting and transformation.

(II) technical scheme

In order to achieve the purpose, the invention adopts the main technical scheme that:

the invention provides a method for updating and transforming chestnut tree full-crown lower branch supplement and excellent variety change, which comprises the steps of carrying out branch closure grafting on main branches under the chestnut tree full-crown, and realizing crown inner branch supplement or variety change and excellent variety change through grafting; the main branch is a branch directly connected with the trunk; the method comprises the following steps:

s1, selecting a main branch as the rootstock;

s2, making a grafting opening: taking one surface of the selected main branch with smooth side surface and no mechanical damage as a grafting surface, performing circular cutting on the main branch for one circle to form a circular cutting wound, wherein the circular cutting depth is based on reaching xylem, then taking the circular cutting wound as a starting point to cut the cortex downwards along the extending direction of the main branch to form a longitudinal incision, and picking the cortex on the left side and the right side of the longitudinal incision by using a knife to form a T-shaped grafting opening together with the circular cutting wound; cutting an inverted U-shaped groove with gradient on the main branch at a position above the annular incision and aligned with the longitudinal incision, wherein the incision at one end close to the annular incision is deeper, and the incision at one end far away from the annular incision is shallower;

s3, making a grafting end of the scion: cutting a horse ear-shaped inclined plane at the lower end of the scion and on one side surface opposite to the full bud of the scion, wherein the horse ear-shaped inclined plane starts from a position which is a certain distance away from the lower end of the scion to the lower end of the scion, and the cutting depth is from shallow to deep; after the horse ear-shaped inclined plane is cut, a silk cortex layer is respectively and shallowly cut on the left side and the right side of the back side of the horse ear-shaped inclined plane to expose a cambium layer, and then one side of the lower end of the scion opposite to the horse ear-shaped inclined plane is cut into a wedge shape to form a grafting end of the scion;

s4, grafting: inserting the grafting end of the scion into the T-shaped grafting opening, so that the cambium exposed out of the grafting end of the scion is contacted with the inner side surfaces of the skin layers raised from two sides of the longitudinal cutting opening, and the part of the scion, which exceeds the ring cutting wound, falls into the inverted U-shaped groove; tightly wrapping the scion, the T-shaped grafting opening and the girdling cut by using a binding plastic film or a grafting binding band, and tightly binding and fixing the scion on the main branch to complete grafting;

s5, management after grafting: the main branch as the stock is not cut off in the current year after grafting, the main branch as the stock is cut off or reserved in the second or third year after grafting according to the requirement of crown branch supplement or variety excellent change; the year of cutting off the main branches is determined by the period when the scion branches or the scion branches and the side branches start to bear fruits and the number of the fruits is equivalent to that of the main branches before grafting.

According to the preferred embodiment of the present invention, in S1, when selecting the main branch as the rootstock, the main branch is selected from the group consisting of a chestnut tree with bald inner bore, a bearing-less branch in the crown or a branch group.

According to the preferred embodiment of the present invention, in S2, the position of the cut wound on the main branch is 0.6-1.2m away from the main trunk of the chestnut tree. This position of the main branch is usually a bald zone (without lateral branches), which facilitates the operation of grafting and the survival of the scion. Preferably, the T-shaped grafting opening is preferably located at a position on the side surface and the upper surface of the main branch.

According to the preferred embodiment of the present invention, in S2, the length of the inverted U-shaped groove is 1-2 cm. After the ring cutting wound is cut by a cutter, a cut-off effect is formed on the nutrition transmission of the main branch, and the bud of the scion is promoted to germinate and grow fast. Meanwhile, the width of the ring cutting wound is only the width of the blade, the bark is not peeled, the nutrition conveying of the main branch is only temporarily influenced, generally, a callus is formed after 5 to 7 days, the nutrition conveying is gradually recovered and the growth is started, and therefore, the method is favorable for promoting the rapid survival and germination of the scion and simultaneously does not influence the main branch and the lateral branch results on the main branch.

According to the preferred embodiment of the invention, in S3, the scion is selected before the grafting end of the scion is made, the strong, disease and insect damage free and mechanical damage free bearing mother branch or vegetative branch is used as the scion, the length of the scion is 15-30cm, the thickness is 0.4-0.8cm, 4-6 plump buds are arranged on the scion, and grafting is carried out when the rootstock sprouts to be enlarged without leaf expansion. For example, the grafting time of Xinglong county in Chengdi city is 4 months, 20 days to 5 months and 10 days.

According to the preferred embodiment of the present invention, in S3, the horse-ear shaped inclined plane is formed by cutting from a position 5-8cm away from the lower end of the scion to a depth from half of the wood part to the back side of the knife entering face to form a horse-ear shaped inclined plane 5-8cm long.

S3, when the grafting end of the scion is manufactured, each cutting surface needs to be smooth and has no stubble, so that the rapid healing of the stock and the scion is facilitated, the scion cutting speed needs to be increased as much as possible, the grafting is carried out immediately after the scion is cut, and the exposure time of the scion in the air is reduced.

In S4, when the grafting end of the scion is inserted into the T-shaped grafting opening, the force is applied slowly until the upper end of the wedge-shaped cutting surface is overlapped with the ring cut of the stock. After grafting, 3-5 layers of plastic films are bound at the T-shaped grafting opening, the T-shaped grafting opening of the grafting stock, the ring cut wound and the scion are bound tightly and completely, and the grafting survival rate is prevented from being influenced by wind blowing and shaking of the scion and water inflow in rainy days.

According to the preferred embodiment of the invention, in S5, in the current year of grafting, the length of a new shoot formed by scion survival is controlled to be 30-60cm, and the scion branch which is too long and does not stop growing is subjected to pinching treatment, so that the scion branch generates lateral branches, and a fruiting branch group consisting of a plurality of branches can be obtained. Preferably, the new sprouted branches are subjected to pinching treatment when the length of the new sprouted branches reaches 60 cm.

According to a preferred embodiment of the present invention, in S5, the post-grafting management comprises:

when the branch is supplemented in the crown, the branches and leaves above the scion are trimmed and thinned in the same year (the shaded branches and leaves are mainly removed), ventilation and light transmission of the inner cavity are increased, the scion is promoted to sprout new branches, and the number of fruit branches or fruit branch groups in the inner cavity is increased;

when the variety is required to be changed to be excellent, the main branch of the stock is not cut off in the current year of grafting, the main branch of the original variety is cut off (sheared or sawed) above the grafting part in the next year or the third year, and the scion branch is cultured to become a new bearing branch and bearing branch group, so that the purpose of changing the variety to be excellent is achieved.

According to the preferred embodiment of the present invention, in S5, after the main branch as the rootstock is cut, the cut surface is subjected to pest control treatment. The pest control treatment comprises the following steps: when the cut-off is carried out, the cut-off surface is kept smooth, and the cut-off surface is coated with the methylthio naphthalene acetic acid in time so as to protect the wound and avoid the cut-off surface from forming rot disease and insect symbiosis and weakening the tree vigor. The pests are trapped and killed by using lamplight, pest sticking glue, pest sticking plates, sex attractant, sugar-vinegar liquid, machinery, artificial catching or a weed stem.

(III) advantageous effects

The invention has the main technical effects that:

(1) in the invention, under the full-crown state of the chestnut tree (without cutting off main branches), a circle of ring cutting is performed on the grafting position of the branches to form a ring cutting wound, and then a skin-inserting and abdomen grafting method is adopted to graft a good variety fruiting mother branch or a vegetative branch which grows strongly and has no diseases and insect pests. As the main branch serving as the stock is not cut to be dry in the current year, the girdling wound can be healed quickly, and the fruiting quantity of the main branch of the stock is not affected basically, the method does not affect the fruiting quantity of the grafting in the current year, realizes the updating of the inner bore branch supplement under the conditions of no yield reduction, little yield reduction, no reduction or little income reduction, and solves the problem of bore baldness.

(2) The variety of the chestnut tree is changed under the whole crown, the chestnut tree is not cut off and not pruned in the current year of grafting, and the original variety yield can be kept. The quality can be removed and the excellent can be remained in the third year according to the growth and the fructification of the scion, and the purpose of changing the variety can be achieved under the condition of no or little yield reduction.

(3) The Chinese chestnut tree is updated and reformed under the full crown, the main branches used as the rootstocks mainly comprise the inner bore of the tree body and the sparsely distributed positions of the main branches, the Chinese chestnut crown can be artificially reformed according to the expected direction, the nutrients of the tree body are uniformly dispersed, the latent buds grow less, tillers are not needed, the growth amount of scion branches after grafting is moderate, the phenomenon that the branches grow vigorously to form overgrown branches is avoided, the labor amount is reduced, and the tillering cost and the management cost are saved.

(4) The full-crown lower branch-supplementing and excellent-changing method of the chestnut trees is simple to operate, the scion survival rate reaches over 95 percent, and the chestnut trees do not need to be erected and tied up for support after being grafted, so that the management cost is reduced.

The method for modifying the chestnut tree with low yield and poor quality by branch supplementing and changing under the whole canopy is suitable for modifying the chestnut tree with low yield and poor quality, modifying the chestnut tree with bald area and modifying the close planting closed chestnut garden, and the like, and the variety is changed and modified under the conditions of no yield reduction, less yield reduction, no reduction or less income reduction. During 2019 plus 2021, after the method is used in a chestnut garden in Xinglong county in Chengde City, the chestnut trees can achieve the purposes of not reducing yield in the current year, stabilizing yield in the 2 nd year, increasing yield, changing varieties into inferior and changing varieties into superior through grafting and variety changing transformation.

Drawings

FIG. 1 is a schematic diagram of the selection of the present invention as the main branch of the rootstock and the grafting position.

FIG. 2 is a schematic view of the present invention illustrating the fabrication of a grafting opening during grafting by the grafting method.

FIG. 3 is a schematic view of the present invention showing the grafting end of the scion prepared by grafting with the bark-grafting and belly-grafting method.

FIG. 4 is a schematic view of the present invention after grafting by grafting.

FIG. 5 shows the growth of the second year after the branch-supplementing grafting of example 1 of the present invention.

Fig. 6 is a schematic view of the case of stem cutting of the main branch in the second year of the modified grafting and the superior grafting in embodiment 2 of the present invention.

Detailed Description

For the purpose of better explaining the present invention and to facilitate understanding, the present invention will be described in detail by way of specific embodiments with reference to the accompanying drawings.

The invention mainly aims to solve the problems of baldness of the inner cavity of a chestnut tree, outward shift of fruiting parts, updating of chestnut varieties and the like. The method can be used for updating and transforming the Chinese chestnut tree in a full-crown state, and achieves the purposes of updating the Chinese chestnut inner bore branches and changing varieties without reducing or slightly reducing the yield of the Chinese chestnuts, so that the outstanding problems of low yield, poor benefit, disordered varieties, no yield or yield reduction during variety updating and the like of the Chinese chestnuts are effectively solved, the labor amount is reduced, the management labor is reduced, the updating result of the Chinese chestnut inner bore branches and the variety changing are promoted, and the purposes of convenient operation, labor saving, high quality and high yield of the Chinese chestnuts are achieved. The following are preferred embodiments of the present invention.

Example 1

The scheme of the invention is applied to a chestnut garden in Xinglong county in Chengde city in Hebei province, is used for branch supplement or modification in the crown of the chestnut garden, and solves the problems of baldness in the inner cavity and outward displacement of bearing parts of the chestnut trees. The method of this example is as follows:

(1) selecting main branch as stock

As shown in figure 1, because chestnut farmers are not managed in place or are sparsely managed, or continue to use the original pruning method, the chestnut trees grow upwards or overtake, so that the chestnut trees grow higher and higher, the tree bodies are higher and higher, the tree crowns are larger and larger, the chestnut garden is seriously closed, the tree crowns and branches are closed tightly and internally, the amount of branches in inner chambers is small, fruiting parts move outwards, and the phenomena of baldness in inner chambers, no yield or low yield and the like are presented. And aiming at the baldness of the part of the inner bore and the main branches with peripheral results, updating the inner bore branch group or changing the variety and the quality according to the needs. Therefore, when the main branch serving as the stock is selected, the main branch of the chestnut tree with bald inner bore and no bearing branches or branch groups in the crown is selected as the grafting stock, and the new bearing branches or nutrition branches are grafted on the main branch to fill the inner bore branches or the branch groups.

(2) Making grafting openings

As shown in fig. 2, the selected part of the main branch with smooth side surface and without mechanical damage on the upper side is used as a grafting surface, and the rootstock (branch) is girdled by a sharp knife at a position 0.8m away from the main trunk for a circle and reaches the xylem to form a ring cut 11. Then, the skin layer is cut downwards along the extending direction of the main branch by taking the circular cut 11 as a starting point to form a longitudinal cut 12, and the longitudinal cut 12 is vertical to the circular cut 11. The cortex on the left and right sides of the longitudinal incision 12 is folded by a knife and forms a T-shaped grafting opening 10 together with the ring-cut wound 11. An inverted U-shaped groove 13 having a slope is cut in the main branch with a knife at a position approximately aligned with the longitudinal cut 12 above the girth cut 11. The inverted U-shaped slot 13 cuts deeper at the end 131 near the girth cut 11 and shallower at the end 123 distal from the girth cut 11. The inverted U-shaped groove 13 can make the included angle between the main branch and the scion as small as possible after the scion is inserted into the T-shaped grafting opening 10, so that the grafting end of the scion can be closely connected with the stock, thereby being beneficial to the rapid survival and growth of the scion. If the inverted U-shaped groove 13 is not formed, after the scion is inserted into the T-shaped grafting opening 10, the phloem above the circular cutting wound 11 can jack the scion, so that the scion and the stock always have a larger included angle, the grafting end of the scion cannot be tightly attached to the T-shaped grafting opening 10 of the stock, and a gap is formed, so that the scion and the stock cannot form callus easily, and the survival and growth of the scion are influenced. Wherein, the T-shaped grafting opening 10 is positioned at the upper position of the side surface of the main branch.

In the transformation process, the circumferential size of the ring-cut wound 11 is changed, and the result shows that the ring-cut complete circle has better rapid promotion effect on scion germination than the half ring-cut or 1/3 ring-cut. Compared with the whole circle of circular cutting, the semi-circular cutting or 1/3 circular cutting is adopted, so that the scions germinate slowly and grow weakly. The reason is that the cortex of the main branch is cut circularly, the nutrition of the main branch is rapidly enriched below the circular cut wound, and the scion can obtain sufficient nutrition and rapidly survive. And for the main branches of the chestnut trees, the ring-cut wound is easy to self-heal, the callus is generated after about 5 to 7 days, and the nutrition conveying path of the main branches is gradually recovered, so that the top ends of the main branches and the top ends of the side branches can normally bear fruits.

Wherein, if do not cut out longitudinal cut 12 earlier, directly with the sword from the girdling wound 11 to the cortex that goes into the sword on the main branch and lie in the girdling wound 11 below of knife, the cortex can not stretch out and draw back, can't form the grafting interface that supplies the scion to insert of effectual, enough space, such processing method lets cortex internal tissue impaired very easily simultaneously, is unfavorable for wound healing and scion survival.

(3) Making grafting end of scion

The method takes the strong, disease and insect pest free and mechanical damage free original seed vegetative shoots as scions 2, the length of the scions 2 is 15-30cm, the thickness is 0.4-0.8cm, and 4-6 plump buds are arranged on the scions. The grafting time is completed within 20 days of 4 months to 10 days of 5 months.

As shown in figure 3, a 7cm horse ear shaped bevel 21 is cut at the lower end of the scion 2 and opposite to one side of the full bud of the scion. The cutting method is that the cutter is arranged at a position 7cm away from the lower end of the scion 2, the depth of the cutter reaches 1/2 xylem, the cutter is inclined towards the lower end of the scion 2, and the cutting depth is gradually increased in the process. After the horse ear shaped inclined plane 21 is cut, a cortex layer is further cut on the left and right sides of the backside of the horse ear shaped inclined plane to expose the cambium layer, and then a wedge 23 is cut on the side of the lower end of the scion 2 opposite to the horse ear shaped inclined plane 21. This completes the grafting end 20 of the scion. The horse ear shaped inclined plane 21, the forming layer 22 and the wedge 23 form the grafting end 20.

The scion grafting end 20 cut in this way can increase the contact area between the stock and the scion, so that the stock can provide sufficient moisture and nutrition for the scion, thereby effectively improving the grafting survival rate and accelerating the growth of branches. The cut surfaces are required to be smooth and have no stubble, so that the rapid healing of the stock and the scion is facilitated, the cutting speed of the scion is increased as much as possible, the scion is grafted immediately after being cut, and the exposure time of the scion in the air is shortened.

(4) Grafting

As shown in fig. 4, the grafting method is as follows: the grafting end 20 of the scion is slowly and forcefully inserted into a T-shaped grafting opening 10 which is pre-manufactured on the rootstock, so that a cambium 22 exposed on the grafting end 20 of the scion is tightly contacted with the inner side surfaces of the cortex layers which are raised at two sides of the longitudinal groove 12, and the partial section of the scion 2 which protrudes out of the ring cutting wound 11 just falls into the inverted U-shaped groove 13. Due to the arrangement of the inverted U-shaped groove 13, the branch of the scion 2 can be close to the branch of the stock, so that grafting wound healing and scion survival are facilitated, and the main branch can provide a protective effect for the scion. And then, binding the T-shaped grafting opening 10 of the stock, the circular cut wound 11 and the scion 2 by 4 layers by using a binding plastic film, tightly binding and completely wrapping, and avoiding the scion from blowing and shaking and water entering in rainy days to influence the grafting survival rate.

(5) Post-grafting management

Managing the orchard according to a conventional mode, carrying out certain pruning in the current grafting year, removing shading leaves and partial branches, providing sunlight, rain and dew for newly-germinated scions, increasing ventilation and light transmission of trees, and promoting the growth of new branches of the scions in the inner chamber. The survival scion can grow to 30-60cm in the current year of grafting. And (3) pinching the overlong scion branches which do not stop growing, so that more lateral branches can grow on new scion branches after pinching, and a fruiting branch group consisting of a plurality of branches can be obtained. Generally, the newly germinated branches grow to 60cm and are subjected to pinching treatment, so that the inner bore branches can promote new branches to form bearing branches or bearing branch groups, and favorable conditions are provided for the yield of the Chinese chestnuts in the next year. As shown in fig. 5, the bearing branches and branch groups are formed on the main branches of the graft in the second year after the branch supplementing graft of this example.

And after the number of fruiting branches or fruiting branch groups formed by the scions in the second year meets the preset requirement, further cutting off branches and leaves with light shading at the upper part, and reserving the fruiting branches or fruiting branch groups grown by the scions, so that not only are the inner chamber fruiting branches supplemented, the yield of the Chinese chestnut is increased, but also the purpose of crown reduction and transformation of the Chinese chestnut trees is realized. During the period of 2019 plus 2021, after the method is implemented in a chestnut garden in Xinglong county of Chengde city, the aim of supplementing new branches to the inner cavity of a chestnut tree is fulfilled, and the aims of no reduction of yield in the current year, stable yield in the 2 nd year and high yield in grafting are fulfilled.

Example 2

The embodiment is also applied to the chestnut garden in Xinglong county in Chengde city in Hebei for changing the variety of the chestnut garden. The method of this embodiment is the same as embodiment 1, and the differences include the following two points:

in the step (3), the strong, disease and pest free and mechanical damage free good variety bearing mother branches are used as the scions 2, the length of the scions 2 is 15-30cm, the thickness is 0.4-0.8cm, and 4-6 plump buds are arranged on the scions. The grafting time was the same as in example 1.

In the step (5), the orchard is managed according to a conventional mode, and the survival scion can grow to 30-60cm in the current year of grafting. And (3) pinching the overlong scion branches which do not stop growing, so that more lateral branches can grow on new scion branches after pinching, and a fruiting branch group consisting of a plurality of branches can be obtained. In the next year of grafting, when the number of fruity branches or fruity branch groups grown from the scion reaches the preset requirement, the main branches originally used as the rootstocks are cut off obliquely from top to bottom by using scissors or saws above the grafting position, so that the newly-germinated branches are supplied with concentrated nutrition of the tree body to become new fruity branches and fruity branch groups, and the purpose of variety change is achieved (as shown in figure 6). Finally, in order to avoid infecting bacteria or pest and disease damage to the sawing mouth of the stock, the sawing mouth needs to be treated, the sawing mouth is smooth, no pile is left, and the end face of the cut is timely smeared with methyl naphthalene acetic acid to protect the wound and avoid the formation of rot disease and insect symbiosis caused by pile left on the sawing mouth and the weak tree vigor. The pests are trapped and killed by using lamplight, pest sticking glue, pest sticking plates, sex attractant, sugar-vinegar liquid, machinery, artificial catching or a weed stem.

During the 2019-2021 year, after the method is implemented in a chestnut garden in Xinglong county of Chengde city, the goal of upgrading and changing the excellent of the old variety of the chestnut garden is completed, and the purposes of no reduction of yield in the current year, stable yield in the 2 nd year and high yield in grafting are realized.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for updating and transforming chestnut trees by branch supplementing and optimum changing under full canopy is characterized by comprising the following steps: performing branch closure grafting on the main branches under the whole crowns of the chestnut trees, and realizing branch supplement in crowns or variety change optimization through grafting; the main branch is a branch directly connected with the trunk;

the method comprises the following steps:

s1, selecting a main branch as a stock;

s3, making a grafting end of the scion: cutting a horse ear-shaped inclined plane at the lower end of the scion and on the side opposite to the full bud of the scion, wherein the horse ear-shaped inclined plane starts from a position which is a certain distance away from the lower end of the scion to the lower end of the scion, and the cutting depth is from shallow to deep; after the horse-ear-shaped inclined plane is cut, respectively and shallowly cutting a silk skin layer on the left side and the right side of the back side of the horse-ear-shaped inclined plane to expose a new green forming layer, and then cutting one side of the lower end of the scion opposite to the horse-ear-shaped inclined plane into a wedge shape to form a grafting end of the scion;

s4, grafting: inserting the grafting end of the scion into the T-shaped grafting opening, so that the cambium exposed from the grafting end of the scion is contacted with the inner side surfaces of the cortex picked up at the two sides of the longitudinal incision, and the part of the scion exceeding the ring cutting wound falls into the inverted U-shaped groove; tightly wrapping the scion, the T-shaped grafting opening and the girdling cut by using a binding plastic film or a grafting binding band, and tightly binding and fixing the scion on the main branch to finish grafting;

s5, management after grafting: the main branch as the stock is not cut off in the current year after grafting, the main branch as the stock is cut off or reserved in the second or third year after grafting according to the requirement of crown branch supplement or variety excellent change; the year of cutting off the main branches is based on the condition that the scion branches or the scion branches and the side branches thereof start to fruit and the fruit quantity is equivalent to that of the main branches before grafting.

2. The method according to claim 1, wherein in S1, when selecting the main branch as the rootstock, the main branch is selected from chestnut tree with baldness in the inner bore, fruitless branches in the crown or branch groups.

3. The method according to claim 1, wherein in S2, the position of the cutting wound on the main branch is 0.6-1.2m from the main trunk of the chestnut tree.

4. The method of claim 1, wherein in S2, the length of the inverted U-shaped groove is 1-2 cm.

5. The method according to claim 1, wherein in S3, the scion is selected before making the grafting end of the scion, the strong, disease and pest free, mechanical damage free fruiting mother branch or vegetative branch is used as the scion, the length of the scion is 15-30cm, the thickness is 0.4-0.8cm, 4-6 plump buds are on the scion, and grafting is performed when the rootstock bud grows to be enlarged without leaf expansion.

6. The method of claim 1, wherein the horse-ear shaped bevel is cut from a position 5-8cm away from the lower end of the scion to a depth from one half of the xylem to the back side of the rake face to form a horse-ear shaped bevel 5-8cm long in S3.

7. The method according to claim 1, wherein in S5, the length of the young shoot formed by the survival of the scion is controlled to be 30-60cm in the year of grafting completion, and the scion branch which is too long and does not stop growing is subjected to pinching treatment to generate side branches, so as to facilitate obtaining a fruiting branch group consisting of a plurality of branches.

8. The method according to claim 1, wherein in S5, the post-engrafting management comprises: when the branch is supplemented in the crown, branches and leaves above the scion are trimmed and thinned in the same year of grafting, ventilation and light transmission of the inner cavity are increased, scion sprouting is promoted, and the number of fruit branches or fruit branch groups in the inner cavity is increased;

when the variety is required to be changed to be excellent, the main branch of the stock is not cut off in the current year of grafting, the main branch of the original variety is cut off at the grafting position in the next year or the third year, and the scion branch is cultured to become a new bearing branch and bearing branch group, so that the purpose of changing the variety to be excellent is achieved.

9. The method according to claim 1, wherein in S5, after the main branch as the rootstock is cut, the cut surface is subjected to pest control treatment.