Method for improving and optimizing carya illinoensis big tree variety and rapidly increasing yield of carya illinoensis big tree variety

Abstract

The invention belongs to the field of forestry, and particularly relates to a carya illinoensis big tree variety optimization and rapid yield increasing method which comprises the steps of variety selection and configuration, scion collection and preservation, big tree treatment, grafting and post-grafting management. According to the method, multi-head layered grafting is adopted for grafting, new varieties suitable for localized development (which is approved (recognized) by the national or provincial forest and grass improved variety certification committee and is suitable for local development) are used for optimizing original varieties, and integration of a rapid high-yield cultivation technology is matched; compared with other grafting methods (such as stem-cutting grafting and an existing layered grafting technology), the survival rate is increased by 30% or above, and the cultivation period before fruiting is shortened by 3 years or above. According to the method, the scions are treated in a dry ice sand blasting-room-temperature water buffering-low-temperature water heat shock mode, the scion rescue rate can be remarkably increased, and meanwhile the fruit malformation rate of first fruiting of the scions is not affected.

Description

Technical Field

[0001] The invention belongs to the technical field of forestry, and particularly relates to a method for improving the variety of thin-shelled pecan trees and quickly increasing yield. Background Art

[0002] Thin-shelled pecans have not been introduced to the local area for long. Due to improper introduction of early varieties, some varieties are not suitable for local development, lack of commerciality, unreasonable variety configuration and other factors, the development of the thin-shelled pecan industry in some areas has not achieved the expected results, causing huge economic losses and restricting the development of the industry.

[0003] "Stump grafting" is a technique widely used in horticulture and forestry, primarily for improving tree species and increasing yield and quality. The basic principle is to graft a scion (graft) of a superior variety onto the rootstock of the target tree species, allowing the cambium between the scion and the rootstock to heal, thereby achieving tree renewal and improvement. The specific method is as follows:

[0004] Cut-stem grafting involves cutting the rootstock and then inserting the scion into the cut, aligning it with the cambium layer of the rootstock. This method is commonly used to improve and regenerate varieties of various plants, including fruit trees, oil tea, tea, and mulberry trees.

[0005] However, for the grafting of thin-shelled walnuts, in Anhui Province, the use of stem cutting grafting has certain limitations (such as it is not easy to survive, and the tree shape needs to be re-cultivated after stem cutting grafting). Figures 1-2 As shown, when the thin-shelled pecan tree was grafted by cutting the stem, it did not survive.

[0006] Layered grafting is a technique that involves grafting selected side branches onto mature fruit trees to improve yield and quality. This method is particularly suitable for tall, mature fruit trees or fruit trees used for both timber and fruit. The general steps are as follows:

[0007] 1) Prepare the rootstock and scion: Select healthy side branches as the rootstock and choose a scion with excellent characteristics.

[0008] 2) Peeling and docking: Peel the side branches of the rootstock, fix the scion on the peeled part, cover the scion with moist medium (such as rotten soil), and wait for it to take root.

[0009] 3) Protection and management: After grafting, the growth of the scion needs to be checked regularly and appropriate protection should be provided to ensure its smooth rooting and growth.

[0010] The existing conventional layered grafting technology also has certain limitations for grafting thin-shelled pecan trees, such as limited survival rate and easy wind breakage. Summary of the Invention

[0011] The purpose of the present invention is to provide a method for improving the variety of thin-shelled pecan trees and quickly increasing yield, so as to solve the above-mentioned problems.

[0012] A method for improving the quality of large walnut tree varieties and achieving rapid and high yield, comprising the following steps:

[0013] Step 1: Product selection and configuration

[0014] Select the thin-shelled pecan varieties that are suitable for local development and have been approved (recognized) by the national or provincial forestry and grassland variety approval committee, and configure pollination varieties according to the characteristics of the varieties;

[0015] Step 2: Scion collection and preservation

[0016] The collection work is completed between the time when leaves fall in winter and before buds sprout. The branches of the current year of the perennial thin-shelled pecan trees are selected as scions. The two ends are sealed with melted paraffin wax, sorted, and stored in sealed bags in a cold storage at 3-5℃.

[0017] Step 3: Large tree processing

[0018] Prune all large walnut trees that need improvement from leaf fall to 20 days before grafting. Prune according to the growth of the tree and the cultivation goal of trunk layering. The first layer of branches should be no less than 1.5m, and the interval between each layer should be no less than 60cm. It should be divided into 2-3 layers, with the center pole height no less than 3.5m. Each tree should retain no less than 10 branches at the grafting position. Select 3-4 branches of different angles and thickness in each layer according to the shape of the tree, and cut and retain 50cm.

[0019] Step 4: Grafting

[0020] The grafting time is from early to mid-April to mid-May, and the grafting time does not exceed 20 days. The grafting method is as follows:

[0021] Awakening treatment: Take the scion out of the cold storage and place it in a cool place to return to room temperature. Start grafting after 12 hours.

[0022] Cutting treatment: Cut the scion to 8±1cm in length, leaving 1-2 full buds, and use it as the scion for each branch;

[0023] Peeling: Peel according to the position of the bud point. The bud point side is used as the short side, and the peeling angle is 45±1°, with a cross section of 1±0.5cm. The symmetrical side of the short side is used as the long side, and the peeling angle is 20±2°, with a broken surface length of 3.5±1cm.

[0024] Cutting treatment: Use a sharp knife to cut the bark of the grafted branch as the grafting rootstock vertically, with a length of 4±1cm, cutting through the xylem to the cambium of the tree body; the number of grafts is determined according to the diameter of the rootstock, with one branch grafted for every 5±1cm diameter; the cutting positions are selected according to the number of grafts, and are evenly distributed, with no more than 3 cuts;

[0025] Grafting: Insert the cut scion into the crack with the long side inward and the short side outward. Make sure there is no gap between the long side and the stock, and the contact length should be no less than 3 cm. Leave 0.5 ± 0.1 cm as the healing opening.

[0026] Binding treatment: Use grafting film to bind and seal the grafting interface;

[0027] Cutting treatment: When grafting large trees, the tree nutrition is cut off by cutting off the roots or opening the water outlet;

[0028] Step 5: Post-connection management

[0029] Carry out disease and insect pest control, sprout removal, wind protection, bird damage prevention, and autumn grafting.

[0030] As a further improvement, in step 1, the ratio of grafted varieties to pollinated varieties is 8:1.

[0031] As a further improvement, in step 2, a wet cloth is placed in each sealed bag, and the sealed bag is opened once every 7 days to replace the wet cloth and remove the air from the sealed bag to replenish fresh air.

[0032] As a further improvement, in step 4, the scion that has suffered from water loss and shrinkage is remedied, and the remedial method includes the following steps:

[0033] Use a dry ice sandblasting machine to dry ice blast the bottom of the scion that has lost water and shrunk for 75 to 80 seconds. The flow rate of dry ice particles is 0-1.0 kg / min, the particle size of dry ice particles is less than or equal to 0.5 mm, and the compressed air pressure is 0.1 MPa. After dry ice sandblasting, immediately insert the bottom of the scion into clean water at 15 to 20°C for 10 to 20 seconds, and then insert it into warm water at 30±2°C for 13 to 15 minutes.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] 1. The present invention adopts multi-head layered grafting, uses new varieties suitable for local development to improve the original varieties, and integrates supporting rapid and high-yield cultivation technology. Compared with other grafting methods (such as stem cutting grafting and existing layered grafting technology), the survival rate is increased by more than 30%, and the cultivation period before fruiting is shortened by more than 3 years.

[0036] 2. The contact surface of the cambium is large, the wound recovers quickly, the survival rate of one grafting is high, and the growth is not easily affected by wind after grafting.

[0037] 3. To remedy the scion that has lost water and shrunk, the scion is treated by the method of dry ice sandblasting-room temperature water buffering-low temperature water heat shock of the present invention, which can significantly improve the scion survival rate (relative to the conventional warm water immersion method, ice water bath immersion method, hot water-cold water alternating stimulation method, etc.), and at the same time, does not affect the fruit deformity rate of the scion when it first bears fruit. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 Photo 1 is a photo of a thin-shelled pecan tree grafted with a stem cut using the prior art;

[0039] Figure 2 Photo 2 is a photo of a thin-shelled pecan tree grafted using stem cutting technology;

[0040] Figure 3 Photo 1 of the multi-layered grafting of Example 1 of the present invention;

[0041] Figure 4 Photo 2 of the multi-layered grafting of Example 1 of the present invention;

[0042] Figure 5 This is a photo of the high-yield tree obtained after multi-layer grafting in Example 1 of the present invention. DETAILED DESCRIPTION

[0043] The present invention will be further described in detail below through specific embodiments in conjunction with the accompanying drawings.

[0044] Example 1

[0045] 1. Variety selection and configuration.

[0046] Select thin-shelled pecan varieties suitable for local development that have been approved (recognized) by the national or provincial forestry and grassland variety approval committee, and configure pollination varieties according to the characteristics of the varieties. The ratio of main grafted varieties to pollination varieties is 8:1.

[0047] 2. Collection and preservation of scion.

[0048] The scion grafts are collected between winter leaf fall and bud break, typically from December to January of the following year. Select branches from well-established, perennial, thin-shelled pecan trees of the current year. Cut the middle section of the 60-80 cm, pest-free branches with plump buds. Seal the ends with melted paraffin wax and bundle them into bundles of 50. Each bundle is sorted by variety and stored in transparent, sealed bags in a cold storage facility at 3-5°C. Place a damp cloth in each bag to maintain moisture. Open the bag every seven days to replace the damp cloth and remove air from the bag to replenish fresh air, ensuring the scion's moisture and oxygen levels.

[0049] 3. Handling of large trees.

[0050] Prune all large, thin-shelled pecan trees requiring improvement between leaf fall and 20 days before grafting. Prune according to the tree's growth and the trunk's layered cultivation goals. The first layer of branches should be no less than 1.5 meters, with each layer spaced no less than 60 cm apart. Generally, the tree should be divided into two or three layers, with a central stem no less than 3.5 meters high. Each tree should retain at least 10 branches for grafting. For each layer, select three or four branches of equal thickness, distributed at different angles according to the tree's shape, and cut back to a 50 cm radius. For any large pruning wounds not intended for grafting, apply a wound healing agent.

[0051] 4. Grafting.

[0052] Grafting should be done between early and mid-April and mid-May, adjusted according to weather and temperature conditions. The starting time should be one week after the bud break of the local thin-shelled pecans. To ensure uniform management, the grafting period should not exceed 20 days. Continuous rainy days are not suitable for grafting.

[0053] Wake up: Take the scion out of the cold storage and place it in a cool place to return to room temperature. Start grafting after 12 hours.

[0054] Cutting: Cut the scion into 8 cm lengths, leaving 1-2 full buds, and use them as the scion for each branch.

[0055] Peeling: Peel according to the position of the bud point. One side of the bud point is used as the short side, and it is peeled at 45°, with a cross-section of about 1cm; the symmetrical side of the short side is used as the long side, and the peeling angle is 20°, with a broken surface length of 3.5cm.

[0056] Cutting: Use a sharp knife to cut the bark of the grafted branch vertically, 4 cm in length, from the xylem to the cambium. The number of grafts depends on the diameter of the rootstock; for a 5 cm diameter branch, one graft is used; for a 10 cm diameter branch, two grafts are used. Choose the location of the cuts based on the number of grafts, distributing them evenly. Generally, no more than three cuts are used.

[0057] Grafting: Insert the cut scion into the broken position, with the long side inside and the short side outside. There should be no gap between the long side and the rootstock, and the contact length should be no less than 3cm. Leave 0.5cm as the healing mouth.

[0058] Binding: Use 2-wire PE grafting film for binding to ensure that the grafting port is water-proof and air-proof.

[0059] Cutting: When grafting large trees, the roots are cut off or water outlets are opened to cut off the nutrients of the tree, reducing the risk of incomplete graft healing due to excessive nutrients.

[0060] 5. Post-transmission management.

[0061] 1) Pest and disease control, mainly pests such as aphids and beetles that harm young branches.

[0062] 2) After the grafted branches sprout, the branches sprouting on the rootstock are cleaned up.

[0063] 3) Prevent wind and bird damage, and prevent storms, birds, etc. from damaging new sprouts.

[0064] 4) Autumn re-grafting: For individual branches that did not survive the spring grafting, a re-grafting (block bud grafting) should be organized in autumn.

[0065] 6. Advantages.

[0066] 1) High survival rate. The survival rate of one graft is over 95%, and the survival rate of grafting in autumn is over 99%, which is 30% higher than other methods.

[0067] 2) Fast results. The grafting survival rate is high, the tree recovers quickly, and its growth is not affected. Fruit will appear in three years and yield will be achieved in five years, two years earlier than other methods.

[0068] 3) Strong wind resistance. After grafting, the wound heals quickly and the wind resistance is strong, with the wind deflection rate reduced by more than 90%.

[0069] 4) Easy to manage. Subsequent management reduces the need to cultivate the tree again, such as Figures 3-5 As shown, management difficulty is reduced by 30% and costs are reduced by 15%.

[0070] Example 2

[0071] If the scion is stored in a cold storage, if the temperature is too low (below 0°C), the scion may suffer from frost damage, resulting in tissue damage, affecting its vitality and graft survival rate. For example, when the temperature is below -4°C, the scion bud will be frozen.

[0072] Although the humidity inside the cold storage is high, because the scion is stored in a transparent sealed bag, if the humidity inside the bag is insufficient, the scion may still lose water due to evaporation, causing the branch to shrink and affecting its physiological activity. For example, when the humidity is below 80%, the scion is prone to water loss and shrinkage.

[0073] For scions that lose water and shrink, the moldy and rotten ones should be picked out. Judging the degree of water loss and shrinkage of the remaining scions is an important part of the management before and after grafting, which directly affects the vitality of the scions and the grafting survival rate.

[0074] 1. Judgment criteria for scion water loss and shrinkage

[0075] 1.1. Intuitive judgment method

[0076] Determine whether the scion has shrunk due to water loss by observing its appearance.

[0077] 1) Normal scion: The bark of the branch is round and bright, without wrinkling or discoloration, and the cambium is bright green, indicating that the scion has good vitality.

[0078] 2) The scion has lost water and shrunken: The bark of the branch is wrinkled and discolored, the cross section is white, and it feels straight and hard, indicating that the scion has lost water and the survival rate is low.

[0079] 3) Lifeless scion: The bark of the branch is wrinkled and discolored, and the cambium turns brown or white, indicating that the scion has lost its vitality.

[0080] 1.2. Callus identification method

[0081] 15 days before grafting, cut the scion into small pieces and place them in a moist environment to observe whether callus tissue grows on the cambium layer of the slope. If callus tissue can be formed, it means that the scion has good vitality and callus ability. (This method can only be used for post-verification or laboratory verification; because in practice, whether the scion loses water and shrinks is usually discovered on a large scale on the eve of grafting. At this time, it is too late to conduct callus tissue identification, which will affect the grafting cycle).

[0082] 1.3. Judgment of survival after grafting

[0083] 1) Survival of the scion: The bark remains green and the buds begin to sprout, indicating that the grafting is successful.

[0084] 2) Unsuccessful scion: The bark is wrinkled and dry, and the buds are shriveled or blackened, indicating that the grafting has failed.

[0085] In this example, we simulated the shrinkage of scions due to water loss. A batch of scions were stored in a cold storage facility for 10 days without a damp cloth in the sealed bags. Most of the scions exhibited water loss and shrinkage. These scions were screened for water loss and shrinkage, and samples were taken to verify their vitality using the callus tissue identification method. These scions underwent remedial treatment and were divided into control groups 1 to 5, a blank group, and an experimental group. The results are shown in Table 1.

[0086] Table 1

[0087]

[0088]

[0089] Scion survival rate = number of surviving scions / (number of water-dehydrated and shrunken scions determined by visual judgment - number of inanimate scions determined by callus identification method).

[0090] The first fruit deformity rate for the scion is calculated as: total number of deformed fruits divided by total number of harvested fruits. Deformed fruit is defined as irregular shape, asymmetry, a pointed base, or a slightly curved top. Generally, the first-year fruit deformity rate for normal pecans is less than or equal to 7%.

[0091] The scion treatment method for the experimental group was as follows: the bottom of the scion was dry-ice blasted for 75 seconds using a dry ice sandblasting machine. The flow rate of dry ice particles was 0-1.0 kg / min, the particle size of dry ice particles was less than or equal to 0.5 mm, and the compressed air pressure was 0.1 MPa. After dry ice blasting, the bottom of the scion was immediately immersed in clean water at 15-20°C for 10 seconds, and then immersed in warm water at 30±2°C for 13 minutes.

[0092] For the blank group, scion preparation was as follows: Use clean scissors to cut the base of the flower stem or branch 1-2 cm diagonally to increase the water absorption area and help the plant absorb water quickly. The base of the scion was then immersed in clean water at 15-20°C for 20 minutes.

[0093] The scion treatment method for control group 1 was as follows: the bottom of the scion was dry-ice blasted for 75 seconds using a dry ice blasting machine. The flow rate of dry ice particles was 0-1.0 kg / min, the particle size of dry ice particles was less than or equal to 0.5 mm, and the compressed air pressure was 0.1 MPa. After dry ice blasting, the bottom of the scion was immediately immersed in clean water at 15-20°C for 13 minutes.

[0094] The scion treatment method of control group 2 was as follows: the bottom of the scion was inserted into clean water at 15-20℃ for 10-20s, and then into warm water at 40±2℃ for 13min.

[0095] The scion treatment method for control group 3 was as follows: the bottom of the scion was immersed in a 0-4℃ ice water bath for 75s; after the ice water bath treatment, the bottom of the scion was immediately inserted into 15-20℃ clean water for 10s, and then into 30±2℃ warm water for 13min.

[0096] The scion treatment method of control group 4 was as follows: the bottom of the scion was soaked in a 0-4°C ice water bath for 10 minutes.

[0097] Reference group: The maple poplar scion was treated according to the scion treatment method of the experimental group, using the same multi-head layered grafting method.

[0098] As shown in Table 1, even if conventional warm water immersion, ice water bath immersion, and hot and cold water alternating stimulation methods are used to treat the scion of thin-shelled pecan, the resuscitation effect is limited and the improvement is not obvious. However, if the scion is treated with the method of dry ice sandblasting followed by room temperature water buffering and low temperature water heat shock according to the present invention, the scion survival rate can be significantly improved.

[0099] In addition, when studying the dry ice sandblasting process, it was found that the compressed air pressure has a significant impact on the scion. If the pressure reaches 0.22MPa or above, the base of the scion will 100% rot and will not survive. When the pressure is between 0.1 and 0.22MPa, although the scion survival rate is greater than 66%, the main finding is that the fruit deformity rate of the first scion fruit will be abnormal, as shown in Table 2:

[0100] Table 2

[0101]

[0102] Therefore, preferably, the pressure of the compressed air is 0.1 MPa.

[0103] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A method for improving the variety of thin-shelled pecan trees and quickly increasing yield, characterized in that: The following steps are involved: Step 1: Product selection and configuration Select improved varieties of thin-shelled pecans and configure pollination varieties according to their characteristics; Step 2: Scion collection and preservation The collection work is completed between the time when the leaves fall and the time when they sprout in winter. The branches of the perennial thin-shelled pecan trees of good quality are selected as scions. The two ends are sealed with melted paraffin wax, sorted, and stored in sealed bags in a cold storage at 3-5℃. Step 3: Large tree processing Prune all large walnut trees that need improvement from leaf fall to 20 days before grafting. Prune according to the growth of the tree and the cultivation goal of trunk layering. The first layer of branches should be no less than 1.5m, and the interval between each layer should be no less than 60cm. It should be divided into 2-3 layers, with the center pole height no less than 3.5m. Each tree should retain no less than 10 branches at the grafting position. Select 3-4 branches of different angles and thickness in each layer according to the shape of the tree, and cut and retain 50cm. Step 4: Grafting The grafting time is from early to mid-April to mid-May, and the grafting time does not exceed 20 days. The grafting method is as follows: Awakening treatment: Take the scion out of the cold storage and place it in a cool place to return to room temperature. Start grafting after 12 hours. Cutting treatment: Cut the scion to 8±1cm in length, leaving 1-2 full buds, and use it as the scion for each branch; Peeling: Peel according to the position of the bud point. The bud point side is used as the short side, and the peeling angle is 45±1°, with a cross section of 1±0.5cm. The symmetrical side of the short side is used as the long side, and the peeling angle is 20±2°, with a broken surface length of 3.5±1cm. Cutting treatment: Use a sharp knife to cut the bark of the grafted branch as the grafting rootstock vertically, with a length of 4±1cm, cutting through the xylem to the cambium of the tree body; the number of grafts is determined according to the diameter of the rootstock, with one branch grafted for every 5±1cm diameter; the cutting positions are selected according to the number of grafts, and are evenly distributed, with no more than 3 cuts; Grafting: Insert the cut scion into the crack with the long side inward and the short side outward. Make sure there is no gap between the long side and the stock, and the contact length should be no less than 3 cm. Leave 0.5 ± 0.1 cm as the healing opening. Binding treatment: Use grafting film to bind and seal the grafting interface; Cutting treatment: When grafting large trees, the tree nutrition is cut off by cutting off the roots or opening the water outlet; Step 5: Post-connection management Carry out disease and insect pest control, sprout removal, wind protection, bird damage prevention, and autumn grafting.

2. The method for improving the variety and quickly increasing the yield of large walnut trees according to claim 1, characterized in that: In step 1, the ratio of grafted variety to pollinated variety is 8:

1.

3. The method for improving the variety and quickly increasing the yield of large walnut trees according to claim 1, characterized in that: In step 2, place a wet cloth in each sealed bag. Open the sealed bag once every 7 days to replace the wet cloth and remove the air from the sealed bag to add fresh air.

4. The method for improving the variety and quickly increasing the yield of large walnut trees according to claim 1, characterized in that: In step 4, the scion that has lost water and shrunk is remedied. The remedial method includes the following steps: Use a dry ice sandblasting machine to dry ice blast the bottom of the scion that has lost water and shrunk for 75 to 80 seconds. The flow rate of dry ice particles is 0-1.0 kg / min, the particle size of dry ice particles is less than or equal to 0.5 mm, and the compressed air pressure is 0.1 MPa. After dry ice sandblasting, immediately insert the bottom of the scion into clean water at 15 to 20°C for 10 to 20 seconds, and then insert it into warm water at 30±2°C for 13 to 15 minutes.

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