Method for renewing and rejuvenating old pomegranate trees

Abstract

The invention discloses a method for renewing and rejuvenating old pomegranate trees. The method comprises the following steps: 1) preparing scions; (2) grafting part selection and pretreatment; 3) drilling and cleaning the rootstock; 4) scion cutting and scion pretreatment; 5) grafting; 6) management after grafting; wherein a grafting healing agent is used in the step 3), the step 4) and the step 5), and the grafting healing agent comprises a callus inducer, an antioxidant and a bactericide. Drilling grafting adopted in the method can be directly carried out on the trunk of the old pomegranate tree, and operation is simple and feasible; the grafting healing agent is used, so that the grafting survival rate is effectively improved. According to the method disclosed by the invention, the grafting callus of the old pomegranate tree is formed quickly, and the scion germination time is shortened and is 7-10 days shorter than that after conventional grafting; the grafting survival rate is high and reaches 90% or above. The method disclosed by the invention can be used for tree form transformation of old pomegranate trees, so that the method has good practical application value.

Description

Technical Field

[0001] The invention relates to the technical field of fruit tree cultivation, and in particular to a method for renewing and rejuvenating old pomegranate trees. Background Art

[0002] Pomegranates have been cultivated in my country for more than 2,000 years. In the long-term cultivation process, four traditional pomegranate production areas have been formed, including Huaiyuan in Anhui, Lintong in Shaanxi, Huili in Sichuan, and Zaozhuang in Shandong. Pomegranates are the first fruit that humans have recognized as edible. Their fruits are rich in nutrition and have a unique flavor. They can not only be eaten fresh, but also processed into juice, fruit wine, and other nutritional health products and medicines. In May, "pomegranate flowers are like fire", and in June, flowers and fruits grow at the same time. In the golden autumn season, the fruits are abundant, and in the winter, the branches are strong and powerful. Pomegranates are also widely used in leisure agriculture and landscaping, and can also be made into bonsai.

[0003] As an economic forest, the economic life of pomegranate trees ranges from several decades to several hundred years. In my country's traditional pomegranate producing areas, there are a large number of old trees that are decades or even hundreds of years old. The trees are bald inside, the fruiting parts are moved outward, the fruiting area is small, and the yield is low. Horticultural measures such as retraction and heavy pruning can promote the rejuvenation of large branches outside the crown, but how to solve the baldness inside the tree has always been a problem. Similarly, how to add new branches when making bonsai using old pomegranate stumps is also a problem. Therefore, it is very necessary to develop a method for renewing and rejuvenating old pomegranate trees.

[0004] Pomegranate fruits and plants are rich in polyphenols. Therefore, how to reduce the adverse effects of polyphenols on wound healing during the grafting process and promote the healing of the grafted site, especially the healing of the grafted site of old trees is also an important issue.

[0005] At present, there is no report on the research on drilling and grafting old pomegranate trees for rejuvenation. Summary of the invention

[0006] The invention aims to provide a method for rejuvenating old pomegranate trees to solve the deficiencies of the prior art.

[0007] The present invention adopts the following technical solutions:

[0008] A method for rejuvenating old pomegranate trees, comprising the following steps:

[0009] 1) Scion preparation: Select 1-2 year old branches with a diameter of 0.3-0.5 cm and single axis extension from the pomegranate scion variety; the scion branches are collected from the time when the leaves fall in autumn to before the sap flows in the second year, and they can be grafted immediately after being harvested or after being stored in low temperature sand;

[0010] 2) Selection of grafting site and pre-treatment: In spring, before the sap of the old pomegranate tree (stock) begins to flow, the grafting site is determined according to the growth and shape of the tree; the bark of the grafting site should be intact and free of knots. If there is old and warped bark, it needs to be removed first;

[0011] 3) Drilling and cleaning of rootstock: Select a drill bit that is closest to the diameter of the scion, and drill a hole at a 60-90° angle on the selected grafting site. The hole should reach the wood and not exceed 1 / 2 of the diameter of the grafting site. When drilling, try not to damage the bark around the hole. Before grafting, use a grafting knife to trim the edge of the hole. After the hole is drilled, inject the graft healing agent with a syringe, then suck it out and drain it. Repeat 2-3 times to wash away the sawdust and wound fluid in the hole to prevent browning and pathogen infection.

[0012] 4) Cutting the scion and pre-treatment of the scion: Before grafting, cut the scion branches into 10-20 cm scions, with at least 2-3 full leaf buds on each scion; cut the outer cortex at the lower end of the scion, retaining a part of the cambium, with the length of the cut being basically consistent with the drilling depth, and keep the cut surface smooth and flat; immerse the cut of the cut scion in the graft healing agent for 15-20 minutes to remove pathogens and bleeding fluid on the branch surface;

[0013] 5) Grafting: insert the treated scion into the drill hole, one scion per drill hole, and tap the scion with a tool to make the scion fit closely with the stock, and align the cambium of the scion cut with the cambium of the stock; apply absorbent paper or cotton cloth soaked with a graft healing agent to the grafting point and the vicinity to prevent the continuously exuded polyphenols from affecting the formation of callus tissue and prevent harmful substances including pathogens from entering the grafting site, and then wrap the grafting film up and down along the grafting point on the stock to make the grafting point tightly wrapped, and at the same time wrap the scion with the grafting film to moisturize and fix the scion;

[0014] 6) Management after grafting: After grafting, perform routine management on the rootstock and pay attention to the budding of the scion. For the scion that has not sprouted, replace the grafting site in time for re-grafting; after the scion sprouts, cut the grafting film wrapped around the scion to prevent the grafting film from restricting the growth of the bud. When obvious callus tissue is formed at the grafting site, cut the grafting film wrapped around the rootstock to prevent the grafting film from restricting the growth of the callus tissue or tightening the tree body; when the new shoots on the scion grow to about 20 cm, pinch them; then, according to the growth space, adopt thinning or short pruning methods to promote the formation of main branches or fruiting branches;

[0015] In steps 3), 4) and 5), the graft healing agent includes a callus inducer, an antioxidant and a bactericide; the callus inducer includes 0.1-0.2 mg / L of auxin NAA and 0.8-1.0 mg / L of cytokinin 6-BA; the antioxidant includes 50-100 mg / L of glycine, 50-100 mg / L of ascorbic acid and 0.05-0.1 mg / L of salicylic acid; the bactericide includes a multiple solution of a wettable powder of the bactericide, and the multiple solution of the wettable powder of the bactericide includes 800-1000 times solution of carbendazim or methyl thiophanate.

[0016] Furthermore, in step 3), the drilling is performed using a manual drilling machine or an electric drilling machine.

[0017] Furthermore, in steps 3), 4) and 5), the graft healing agent is prepared by the following method: according to the component ratio and preparation volume of the graft healing agent, each component is weighed, each component is first dissolved with a small amount of water, and then added to the water one by one, mixed evenly, to obtain the graft healing agent.

[0018] Beneficial effects of the present invention:

[0019] The regeneration ability of old pomegranate trees is weak, the wound healing ability is poor, and the rich phenolic substances are very unfavorable for wound healing; therefore, when old pomegranate trees are grafted, reducing the phenolic content, promoting the healing of the grafted parts and improving the regeneration ability can significantly improve the grafting survival rate of old pomegranate trees and accelerate renewal and rejuvenation. The present invention aims to improve the baldness inside the old pomegranate tree body, the outward movement of the fruiting part, the small fruiting area, the low yield, the urgent need for renewal and rejuvenation, and how to add new branches when making bonsai from old pomegranate tree stumps. It is proposed to perform drilling grafting on the trunk of the old pomegranate tree, and use a grafting healing agent to improve the grafting survival rate. The drilling grafting adopted in the present invention can be directly performed on the trunk of the old pomegranate tree, and the operation is simple and feasible; the use of the grafting healing agent effectively improves the grafting survival rate. The method of the present invention forms callus tissue of the old pomegranate tree grafting quickly, shortens the budding time of the scion, and is 7-10d shorter than the budding time after conventional grafting; the grafting survival rate is high, reaching more than 90%. The method of the invention can be used for tree shape transformation of old pomegranate trees, and thus has good practical application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is the survival performance of the 'Feihong' scion grafted into the 'Hongyushizi' pomegranate trunk one month after drilling holes. DETAILED DESCRIPTION

[0021] The present invention is further explained below in conjunction with the examples and drawings. The following examples are only used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0022] Example 1

[0023] Prepare tools, including: pruning shears, grafting knife, drill (electric drill or manual drill), hammer, toilet paper or gauze, and grafting film.

[0024] The specific operations are as follows:

[0025] Before the sap starts to flow in early March, collect the one-year-old branches (about 0.5cm thick) of the variety to be grafted 'Feihong' and place them in a 4℃ refrigerator to keep them moist for later use. Prepare 10L of graft healing agent, which includes 0.15mg / L NAA, 1.0mg / L 6-BA, 100mg / L glycine, 100mg / L ascorbic acid, 0.05mg / L salicylic acid, and 800 times dilution of carbendazim. Select the old 'Red Jade Seed' pomegranate tree (stock) to be renewed and its grafting site. Select a 0.5cm drill bit and install it to start drilling. When drilling, the angle between the drill bit and the stock trunk is about 60°. When drilling to about 3cm, pull out the drill bit, clean the sawdust on the drill bit and continue drilling. Drilling is completed in three times, and the drilling depth is about 4-5cm (the stock grafting site is about 10cm thick). After drilling, use a grafting knife to trim the edge of the drill hole. Inject graft healing agent with a syringe, then suck it out and drain it, repeat 2 to 3 times to wash away the sawdust and bleeding fluid in the borehole to prevent browning and pathogen infection. Before grafting, cut the prepared 'Feihong' branches into 10-20cm scions, with at least 2-3 full leaf buds on each scion. Use a grafting knife to cut off the outer cortex at the lower end of the scion, retain a part of the cambium, and the length of the cut is 4-5cm. Make the length of the scion cut basically consistent with the depth of the drill hole, and keep the cut surface smooth and flat. Immerse the cut of the cut scion in the graft healing agent for 15-20 minutes to remove pathogens and bleeding fluid on the surface of the branch. Then insert the treated scion into the drill hole, one scion per drill hole, and gently tap the scion several times with a hammer to make the scion fit tightly with the rootstock, and align the cambium of the cut scion with the cambium of the rootstock. Soak clean toilet paper or gauze in graft healing agent and apply it to the grafting point and nearby to prevent the continuous exudation of polyphenols from affecting the formation of callus tissue and prevent harmful substances including pathogens from entering the grafting site. Then wrap the grafting film up and down along the grafting point on the rootstock to ensure that the grafting point is tightly wrapped. At the same time, wrap the scion with the grafting film to moisturize and fix the scion. Check the budding of the scion 15-20 days after grafting, and replace the grafting site in time for the scion that has not sprouted and re-graft it; after the scion sprouts, cut the grafting film wrapped on the scion to prevent the grafting film from restricting the growth of the bud. When there is obvious callus formation at the grafting point, cut the grafting film wrapped on the rootstock to prevent the grafting film from restricting the growth of the callus tissue or tightening into the tree. Figure 1 This is the survival performance of the 'Feihong' scion grafted onto the 'Hongyushizi' pomegranate trunk one month after drilling a hole.

[0026] When the new shoots on the scion grow to about 20 cm, pinch them off; then, according to the growth space, thin out or short-cut the scion to promote the formation of main branches or fruiting branches.

Claims

1. A method for rejuvenating old pomegranate trees, characterized in that: The steps include: 1) Scion preparation: Select 1-2 year old branches with a diameter of 0.3-0.5 cm and single axis extension from the pomegranate scion variety; the scion branches are collected from the time when the leaves fall in autumn to before the sap flows in the second year, and they can be grafted immediately after being harvested or after being stored in low temperature sand; 2) Selection of grafting site and pre-treatment: In spring, before the sap of the old pomegranate tree (stock) begins to flow, the grafting site is determined according to the growth and shape of the tree; the bark of the grafting site should be intact and free of knots. If there is old and warped bark, it needs to be removed first; 3) Drilling and cleaning the rootstock: Select a drill bit that is closest to the diameter of the scion, and drill a hole at a 60-90° angle on the selected grafting site. The hole should reach the wood and not exceed 1 / 2 of the diameter of the grafting site. When drilling, be careful not to damage the bark around the hole. Before grafting, use a grafting knife to trim the edge of the hole. After the hole is drilled, inject the grafting healing agent with a syringe, then suck it out and drain it. Repeat 2-3 times. 4) Cutting the scion and pre-treatment of the scion: Before grafting, cut the scion branches into scions of 10 to 20 cm, with at least 2 to 3 full leaf buds on each scion; cut the outer cortex at the lower end of the scion, retaining a part of the cambium, with the length of the cut being basically consistent with the depth of the drill hole, and keep the cut surface smooth and flat; immerse the cut of the cut scion in the graft healing agent for 15 to 20 minutes; 5) Grafting: insert the treated scion into the drilled hole, one scion per drilled hole, and tap the scion with a tool to make the scion fit tightly with the stock, and align the cambium of the scion cut with the cambium of the stock; apply absorbent paper or cotton cloth soaked with graft healing agent to the grafting point and its vicinity, and then wrap the grafting film up and down on the stock along the grafting point to make the grafting point tightly wrapped, and at the same time wrap the scion with the grafting film; 6) Management after grafting: After grafting, perform routine management on the rootstock and pay attention to the budding of the scion. For the scion that has not sprouted, replace the grafting site in time for re-grafting; after the scion sprouts, cut the grafting film wrapped around the scion. When obvious callus tissue is formed at the grafting site, cut the grafting film wrapped around the rootstock; when the new shoots on the scion grow to about 20 cm, pinch them; then, according to the growth space, take thinning or short pruning methods to promote the formation of main branches or fruiting branches; In steps 3), 4) and 5), the graft healing agent includes a callus inducer, an antioxidant and a bactericide; the callus inducer includes 0.1-0.2 mg / L of auxin NAA and 0.8-1.0 mg / L of cytokinin 6-BA; the antioxidant includes 50-100 mg / L of glycine, 50-100 mg / L of ascorbic acid and 0.05-0.1 mg / L of salicylic acid; the bactericide includes a multiple solution of a wettable powder of the bactericide, and the multiple solution of the wettable powder of the bactericide includes 800-1000 times solution of carbendazim or methyl thiophanate.

2. The method for rejuvenating old pomegranate trees according to claim 1, characterized in that: In step 3), the holes are drilled using a manual drilling machine or an electric drilling machine.

3. A method for rejuvenating old pomegranate trees according to claim 1, characterized in that: In steps 3), 4) and 5), the graft healing agent is prepared by the following method: according to the component ratio and preparation volume of the graft healing agent, each component is weighed, each component is first dissolved with a small amount of water, and then added into the water one by one, mixed evenly, to obtain the graft healing agent.

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