CN116034750B - Method for high grafting and seed changing of oil tea - Google Patents

Abstract

The invention belongs to the technical field of grafting of economic forest tree species, and discloses a method for high grafting and seed changing of oil tea, which comprises the following steps: s1, determining grafting time and a grafting mode; s2, selecting a stock; s3, collecting and storing spike strips; s4.1, cutting off and cutting the anvil; s4.2, cutting ears; s4.3, cutting an anvil; s4.4 cutting; s4.5 binding; s4.6 bagging; s4.7 shading; s5.1, changing bags; s5.2, removing bags; s5.3, removing the shading material; s5.4, removing sprouts and pruning; s5.5 unbinding; s5.6, weeding and fertilizing; the invention solves the production problems of slow growth in the first year, large germination removal workload in the first two years, high cost, easy pile drying after grafting and the like of the traditional grafting technology, has the advantages of high grafting survival rate, fast growth in the earlier stage, early production, fast wound healing and the like, and provides an economic, simple and convenient high grafting and seed changing new technology with strong operability and better effect for the transformation of low-yield forest varieties of oil tea.

Description

A method for high grafting and changing oil tea varieties

Technical Field

The invention relates to the technical field of grafting of economic forest tree species, in particular to a method for high-grafting and replacing oil-tea camellia species.

Background technique

Camellia oleifera Abel. is an evergreen shrub or small tree of the genus Camellia (Camellia L.) of the family Theaceae. It is a woody oil tree species unique to my country. It has a history of cultivation and utilization of more than 2,300 years. It is known as the world's four major woody oil plants along with olive, oil palm and coconut. my country is the country with the largest area of camellia oil in the world. Camellia oil usually grows in low mountains and hilly areas. Camellia oil produced from camellia oil seeds is a green and pollution-free product. Its unsaturated fatty acid content is more than 90%, and the content of oleic acid and vitamins in camellia oil is higher than that of olive oil. It is known as "Oriental olive oil" and has high economic and ecological value. The Food and Agriculture Organization of the United Nations (FAO) has promoted it as a healthy and advanced edible vegetable oil. Camellia oil can also be processed into advanced natural skin care products, and the market prospect is very broad.

Low yield and low efficiency of oil-tea has long been a problem faced by the oil-tea industry. As of 2018, the area of oil-tea planting in China reached 4.5665 million ^hm2 , but about 70% of the adult forests were low-yield forests, and the current national average per-acre yield of tea oil is less than 5.0 kg, which is more than ten times the annual yield of high-standard oil-tea forests. At present, compared with seed propagation and ordinary grafting, high-grafting and replacement of main oil-tea varieties is one of the effective methods for transforming economic forest tree species and low-yield forest varieties. High-grafting and replacement can improve the quality of low-yield oil-tea plants, increase oil-tea yield, extend the growth cycle of oil-tea, and shorten the breeding cycle, thereby improving the economy of low-yield oil-tea forests. This method can restore tree vigor in 2 years, bear fruit in 3 years, and achieve high yields in 5 years.

At present, bark grafting and bark grafting are two widely used high-grafting grafting methods. In recent years, most of the transformation of low-yield oil-tea forest varieties in Hunan Province has been carried out by bark grafting. Although its survival rate is relatively high, because bark grafting is grafting first and then cutting the trunk, the nutrient supply of the branches is insufficient. Most of the branches grow less than 8 cm in the year after grafting, and the branches are easily broken by the wind after the shoots are pulled out in the second year. There are many buds and the maintenance cost is relatively high. Therefore, how to obtain a bark grafting method that meets the advantages of simple operation, high grafting survival rate, fast growth in the early stage, early production, and fast healing of trunk wounds is a technical problem that needs to be solved urgently in this technical field.

Summary of the invention

The present invention aims to provide a method for high-grafting and replacing oil tea, so as to solve the problem that the existing bark grafting adopts the method of grafting first and then cutting the stem, resulting in insufficient nutrient supply to the branches, slow growth of the branches after grafting, more buds and high maintenance costs.

In order to achieve the above object, the present invention provides the following technical solutions:

A method for high-grafting and replacing oil-tea camellia, comprising the following steps:

S1. Determine the grafting time and method: the grafting time is from late May to late June, and the grafting method is bark grafting;

S2. Selecting rootstocks: Select low-yield plants that basically do not bear fruit or bear less than 1 kg of fruit all year round in the oil-tea forest with vigorous growth potential as replacement trees. Select 2 to 5 main branches with branch angles of 100° to 150°, straight and smooth trunks, strong production, no diseases and insect pests, and stem diameters of 2 to 6 cm from each oil-tea tree as high-graft replacement rootstocks;

S3, collecting and storing spikelets: Spikelets are collected by strain, and semi-lignified branches of the current year with full development, full axillary buds, strong growth, and no diseases and insect pests are selected; Spikelets are collected in the morning, bundled by variety after collection, labeled, wetted with clean water and placed in plastic bags, the accumulated water in the plastic bags is drained, wet cotton balls are placed in the bags and the bags are tied tightly; the collected spikelets are sealed and stored in a cool and ventilated place or the roots of the spikelets are inserted into moist soil under the shade of trees for storage;

S4. Start grafting:

S4.1. Cutting and trimming the stock: Cut the main branches of the selected stock at 40 to 80 cm from the ground. Avoid tearing the bark of the stock during the sawing process. Leave a few main branches on the tree to support the shade net later. Except for the branches left as nutrient branches, remove all other branches and weeds on the ground near the tree. Avoid leaving stumps when pruning. When trimming the stock, trim the saw cut surface to make it smooth and flat.

S4.2. Cutting the buds: Cut the buds into 5-6 cm segments, with at least one side bud in each segment. Cut off half of the leaves on the buds to reduce evaporation and maintain photosynthesis of the scion. When cutting the buds, cut a 2-3 cm long bevel 1 cm below the other side of the buds. The cutting depth should be slightly enough to see the cut surface of the wood. The pith can be seen at the base, and the cut surface should be kept smooth. Then cut a short bevel less than 1 cm below the side where the buds are located. Then cut the scion above the buds. The scion should be used as soon as possible after cutting. Keep the buds moist while they are being used.

S4.3, cutting the rootstock: According to the size and length of the scion, select a smooth part on the edge of the wood of the rootstock section and make a straight cut down to the edge of the wood, then lift the skin to the left and pull it apart;

S4.4, Scion: Align the long cut surface of the scion with the stock and insert it into the skinning groove, align the cambium on one side, make the cut surface of the scion higher than the cross section of the stock, and then cover the skin of the stock on the short cut surface of the scion;

S4.5, Binding: Use PVC black tape with good elasticity, strong tension and a width of 1.0 to 2.0 cm to bind the scion from bottom to top in a counterclockwise direction. When binding, tighten the film strip to prevent the scion from moving;

S4.6, Bagging: After the stock is tied, immediately put on a white transparent bag. The size of the bag depends on the thickness of the stock and the number of scions. The flat size is 12-15 cm long and 6-9 cm wide. The bag mouth is tied to keep warm and moisturize.

S4.7, Shading: Shade the grafted plants in a place with strong sunlight. The shading area is about ^1.5m2 and the shading height is more than 15cm away from the grafted buds.

S5. Post-grafting management:

S5.1. Bag replacement: After grafting, check whether the transparent plastic bag at the grafting site is damaged at any time. If the bag is found to be leaking, replace it in time.

S5.2, bag removal: When the spike buds grow to more than 2 cm and fill the plastic bag, gradually remove the plastic bag in the evening of cloudy or sunny days. After removing the bag, shade is still provided for 1 to 2 weeks to allow the sprouting axillary buds to gradually adapt to the natural environment. During this stage, attention should be paid to pests such as aphids, green cicadas, and beetles that damage the tender shoots. If pests or diseases are found, spray pesticides in time;

S5.3, remove the shading material: when the grafted axillary buds grow to September and the grafted buds reach a length of more than 10 cm, remove the shading material on a cloudy day or in the evening; at the same time, cut off all branches and sprouts except the grafted buds to prevent them from competing with the grafted buds for water and fertilizer, so that the grafted buds can continue to grow in autumn and increase the growth;

S5.4, pruning and removing sprouts: timely remove the sprouts on the grafted tea oil rootstock, and keep the sprouts on the grafted rootstock that has not survived, and remove the previously retained nutrient branches with pruning shears or saws before the temperature drops in autumn and winter; in addition, pruning should be carried out before the spring shoots in the second year after grafting, and the cross branches and branches growing inward should be pruned to make the crown develop evenly and form a reasonable tree shape. No stumps should be left when removing sprouts and pruning, that is, the pruned branches should be cut from the base;

S5.5, Untying: In the winter of the current year or the spring of the following year, when the new shoots have grown strong, remove the tying bands;

S5.6. Weeding and fertilization: Cut weeds and till the land to 15 to 22 cm every year. Dig and fertilize in the winter of the current year and the spring of the following year. Apply 0.5 kg of special fertilizer for tea oil to each plant each time.

Furthermore, in S3, the spikelets are generally used as soon as they are picked and are sealed and stored in a cool and ventilated place including a cellar or a cool room for 3 to 5 days. If the temperature is too high or the storage time is more than 5 days, they should be stored in a refrigerator.

Furthermore, in S4.1, in addition to the main branches left as the rootstock, 2 to 3 main branches are retained as nutrient branches for transpiration and photosynthesis, and 1 main branch is retained to support the shade net to achieve shading; when cutting the rootstock, the side close to the main branch of the rootstock is required to be higher inside and slightly lower on the outer edge, and the inclination angle of the inner and outer sides is 5° to 15°.

Furthermore, in S4.4, one rootstock is grafted with 1 to 3 scions, and the number of scions is determined according to the stem diameter of the rootstock.

Furthermore, in S4.6, the cover bag is made of white transparent plastic, and the mouth of the cover bag is tied with a plastic rope. The binding should not be too tight or too loose to ensure that the sap can flow out easily after the cover bag is tied, and at the same time the cover bag can be stably fixed. The shape of the plastic bag is adjusted when or after the cover bag is tied to avoid affecting the growth of the scion.

Furthermore, in S4.7, the thickened black agricultural shade net is propped up by using the cut thin bamboo poles and the higher trunk reserved in the middle of the tree to achieve shade. The bamboo poles are inserted vertically into the soil to ensure the firmness of the shade net and prevent it from being blown down by wind and rain. When the thickness of a single-layer shade net is thin, the shade net is folded into two layers for use to achieve the best shade effect.

Furthermore, in S5.1, pesticides are sprayed outside the transparent plastic cover bag to prevent insect pests such as planthoppers and ants from eating the transparent plastic cover bag.

Furthermore, in S5.5, when the growth of new shoots is poor, the tape is first slightly scratched and not completely untied. When the growth is stronger, the tape is completely removed.

The beneficial effects of the technical solution provided by the present invention are:

1. The oil-tea camellia peeling grafting method provided by the present invention is simple and easy to operate, and has a high grafting survival rate. It can be widely used to improve the quality of low-yield oil-tea camellia plants, increase the yield of oil-tea camellia, extend the growth cycle of oil-tea camellia, and shorten the breeding cycle;

2. The existing oil-tea camellia peel grafting takes 2 years to recover the tree vigor, 3 years to bear fruit, and 5 years to reach high yield. The oil-tea camellia peel grafting provided by the present invention can achieve flowering and fruiting in 2 years, and 3 to 4 years to reach high yield. The time to obtain income is 1 to 2 years earlier, and the economic benefit is higher.

3. The oil-tea camellia bark grafting provided by the present invention has vigorous growth, and the length of new shoots, base thickness, number of branches and tree crown width are significantly better than those of the existing oil-tea camellia bark grafting;

4. After the existing oil-tea grafting, a large number of sprouts will grow, and the workload of removing the sprouts in the later stage is large. However, after the oil-tea grafting provided by the present invention, few sprouts will grow, and the workload of removing the sprouts is small, which greatly saves the cost of later maintenance and further improves the economy of the oil-tea.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a diagram showing the effect of cutting the stock in step S4.1 of a method for high grafting of oil tea according to the present invention;

FIG2 is a diagram showing the effect of cutting ears in step S4.2 of a method for high-grafting and replacing oil-tea camellia seeds according to the present invention;

FIG3 is a diagram showing the effect of step S4.3 of cutting the stock and step S4.4 of cuttings in a method for high grafting of oil tea according to the present invention;

FIG4 is a diagram showing the effect of tying with PVC black tape in a counterclockwise manner in step S4.5 of a method for high grafting of oil tea according to the present invention;

FIG5 is a diagram showing the effect of bagging with a transparent plastic bag in step S4.6 of a method for high grafting of oil tea according to the present invention;

FIG6 is a rendering of a method for high grafting of oil tea according to the present invention after bagging in step S4.6 and before setting up a black sunshade net in step S4.7;

FIG. 7 is a diagram showing the effect of constructing a black sunshade net for shading in step S4.7 of a method for high grafting of oil tea according to the present invention;

FIG8 is a diagram showing the effect of the growth after bag removal in step S5.2 of a method for high grafting of oil tea according to the present invention;

FIG9 is a diagram showing the effect of the growth of tea leaves grafted in August of the same year using a method for high grafting of tea leaves of the present invention;

FIG10 is a diagram showing the effect of the growth of the oil-tea camellia grafted in October of the same year using a method for high grafting of the present invention;

FIG11 is a diagram showing the effect of the growth of tea leaves grafted in April of the following year using a method for high grafting of tea leaves according to the present invention;

FIG12 is a diagram showing the effect of the growth of tea leaves grafted in December of the following year using a method for high grafting of tea leaves according to the present invention;

FIG13 is a diagram showing the wound healing effect of the grafting method of the present invention for high grafting of camellia oleifera in October of the same year;

FIG14 is a diagram showing the wound healing effect of a grafting method for high grafting of camellia oleifera in December of the following year;

Detailed ways

The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments:

Implementation location: Oil tea base belonging to Hunan Huayi Agricultural Development Co., Ltd.

As shown in FIGS. 1 to 14 , a method for high-grafting and replacing oil-tea camellia includes the following steps:

S1. The grafting time is from late May to late June in 2020 and 2021, and the grafting method is bark grafting;

S2. Selecting rootstocks: Select low-yield plants that basically do not bear fruit or bear less than 1 kg of fruit all year round in the oil-tea forest with vigorous growth potential as replacement stands. Select 2 to 5 rootstocks with branch angles of about 120°, straight and smooth trunks, strong production, no diseases and insect pests, and stem diameters of 2 to 5 cm from each oil-tea tree as high-graft replacement rootstocks;

S3. Collection and storage of scion: Collect semi-lignified new shoots of ‘Huaxin’ in the morning or evening as scion, and use them immediately without any pretreatment. In addition, bundle the scion transported from other places, hang labels on them, and put them in cartons or foam boxes containing ice packs to prevent the leaves from losing water under high temperatures. After transporting them to the base, store them in a cool and ventilated place, such as a cellar or bury the roots of the scion under the shade of trees. Spray the leaves with water to keep them moisturized, and they can be stored and used continuously for 3 to 5 days. If the temperature is too high or the storage time is more than 5 days, they should be stored in a refrigerator.

S4. Start grafting:

S4.1 Cutting and trimming the stock: Cut the main branch of the selected stock at 40-80 cm from the ground. Be careful to prevent the stock cortex from tearing during the sawing process. Except for the branches used as nutrient branches and branches used for shading, all other branches and weeds on the ground near the plant should be removed. When trimming the stock, use an electric saw to trim the saw cut surface to make it smooth and flat. Among them, in addition to the main branch left as the stock, keep 2-3 main branches as nutrient branches for transpiration and photosynthesis, and keep 1 main branch to support the shade net to achieve shading. When trimming the stock, the side close to the main branch of the stock should be higher inside and slightly lower outside, and the inclination angle of the inside and outside should be 5°-15°.

S4.2. Cutting the buds: Cut the buds into 5-6 cm segments, with at least one side bud in each segment. Cut off half of the leaves on the buds to reduce evaporation and maintain photosynthesis of the scion. When cutting the buds, cut a 2-3 cm long bevel 1 cm below the other side of the buds. The cutting depth should be slightly enough to see the cut surface of the wood. The pith can be seen at the base, and the cut surface should be kept smooth. Then cut a short bevel less than 1 cm below the side where the buds are located. Then cut the scion above the buds. The scion should be used as soon as possible after cutting. Keep the buds moist while they are being used.

S4.3, cutting the rootstock: According to the thickness and length of the scion, select a smooth part on the edge of the xylem of the rootstock section and make a straight cut down to the xylem, then lift the skin to the left and pull it apart;

S4.4, scion: insert the long cut surface of the scion into the skinning groove with the rootstock, align the cambium on one side, and make the cut surface of the scion higher than the cross section of the rootstock. Then cover the skin of the rootstock with the short cut surface of the scion. One rootstock can be grafted with 1 to 3 scions. The number of scions can be determined according to the actual situation and the stem diameter of the rootstock.

S4.5, Binding: Use PVC black tape with good elasticity, strong tension and a width of about 1.5 cm to bind the scion. Bind in a counterclockwise direction from bottom to top. Tighten the tape during binding to prevent the scion from moving.

S4.6, bagging: After the stock is tied, immediately put on a white transparent plastic bag, the flat size of the bag is about 15 cm long and 8 cm wide, and the bag mouth is tied with a plastic rope to keep warm and moisturize; the bag is tied with a plastic rope, and the binding should not be too tight or too loose to ensure that the bag is easy to flow out after the binding, and the bag can be stably fixed. When the bag is tied or after the binding is completed, the shape of the plastic bag is adjusted to avoid affecting the growth of the scion;

S4.7, Shading: Shade the grafted plants in a place with strong sunlight. The shading area is about ^1.5m2 , and the shading height is more than 15cm from the grafted buds. Use the thin bamboo poles and the higher trunk reserved by the tree to prop up the thickened black agricultural sunshade net to achieve shading. The bamboo poles are inserted vertically into the soil to ensure the firmness of the sunshade net and avoid it being blown down by wind and rain. When the thickness of the single-layer sunshade net is thin, fold the sunshade net into two layers to achieve the best shading effect.

S5. Post-grafting management:

S5.1. Bag replacement: After grafting, check whether the transparent plastic cover bag at the grafting site is damaged at any time. If the cover bag is found to be leaking, it should be replaced in time; and pesticides should be sprayed on the outside of the transparent plastic cover bag as needed to prevent insect pests such as planthoppers and ants from eating the transparent plastic cover bag;

S5.2, bag removal: When the spike buds grow to more than 2 cm and fill the plastic bag, gradually remove the plastic bag in the evening of cloudy or sunny days. After removing the bag, shade is still provided for 1 to 2 weeks to allow the sprouting axillary buds to gradually adapt to the natural environment. During this stage, attention should be paid to pests such as aphids, green cicadas, and beetles that damage the tender shoots. If pests or diseases are found, spray pesticides in time;

S5.3, remove the shading material: when the grafted axillary buds grow to September and the length of the grafted buds reaches more than 10cm, remove the shading net on a cloudy day or in the evening. At the same time, cut off all branches and sprouts except the grafted buds to prevent them from competing with the grafted buds for water and fertilizer, so that the grafted buds can continue to grow in autumn and increase the growth;

S5.4, pruning after sprout removal: timely remove the sprouts on the grafted tea oil rootstock, and keep the sprouts on the rootstock that has not been grafted, and remove the previously retained nutrient branches with pruning shears or saws before the temperature drops in autumn and winter; in addition, pruning should be carried out before the spring shoots in the second year after grafting, and the cross branches and branches growing inward should be pruned to make the crown develop evenly and form a reasonable tree shape. No stumps should be left when removing sprouts and pruning, that is, the pruned branches should be cut from the base;

S5.5, Unbinding: In the winter of the current year or the spring of the following year, remove the tape after the new shoots grow strong; if the growth of the new shoots is not good, first slightly scratch the tape and do not completely unbind it. When the growth is stronger, completely remove the tape;

S5.6. Weeding and fertilization: Cut weeds and shallow tillage about 18cm every year. Dig and fertilize in the winter of the current year and the spring of the following year. Apply 0.5kg of special fertilizer for oil tea to each plant each time.

The method was implemented at the oil-tea camellia base of Hunan Huayi Agricultural Development Co., Ltd., with the same routine management. From late May to late June, bark grafting and peeling-off grafting were adopted in the oil-tea camellia test site. The branch length, base thickness of the grafted branch and number of branches were investigated in July, August and October of the current year and April and December of the following year, as shown in Table 1. The survival rate and tree crown width of the two grafting methods were investigated after one and a half years, as shown in Table 2:

Table 1 Growth of Camellia oleifera grafted with bark grafting and bark peeling grafting

Table 2 Survival rate and crown width in the second year of Camellia oleifera using two grafting methods

Grafting method Survival rate/% Crown width (east-west × north-south) (m × m) Plug 94.50 0.81×0.62 Peeling 93.87 0.34×0.29

As shown in Tables 1 and 2, the grafting survival rates of both the grafting methods of bark grafting and the peeling grafting can reach more than 90% for high-grafting of Camellia oleifera. In August of the grafting year, the length and number of branches of the grafted branches increased by 238.36% and 200.00% respectively compared with the peeling grafting. In October of the grafting year, the length of the branches, the thickness of the base of the grafted branches and the number of branches of the grafted branches increased by 208.85%, 57.69% and 258.3% respectively compared with the peeling grafting. 3%, the callus tissue continued to divide, the volume continued to expand, and the gap between the rootstock and scion gradually narrowed; in April of the second year after grafting, the length of the branch, the base thickness of the grafted branch and the number of branches of the bark grafting were 195.77%, 55.07% and 72.97% higher than those of the peeling grafting, respectively; in December of the second year after grafting, the length of the branch, the base thickness of the grafted branch and the number of branches of the bark grafting were 107.14%, 50.50% and 94.00% higher than those of the peeling grafting, respectively, and the grafting wound was completely healed. It can be seen that the improved oil-tea bark grafting technology can have the advantage of fast growth in the first year on the basis of ensuring a high survival rate, so as to achieve early production, and it is not easy to leave stumps, and the cost of grafting and subsequent management is low. It is a new technology suitable for the transformation of low-yield oil-tea forests.

The above is only an embodiment of the present invention, and the common knowledge such as the known specific technical solutions or characteristics in the solution is not described in detail here. It should be pointed out that for those skilled in the art, several modifications and improvements can be made without departing from the technical solution of the present invention, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims (8)

1. A method for high grafting of oil tea, characterized in that it comprises the following steps: S1. Determine the grafting time and method: the grafting time is from late May to late June, and the grafting method is bark grafting; S2, select rootstock: select low-yield plants that basically do not bear fruit or bear less than 1 kg of fruit all year round in the oil tea forest with vigorous growth potential as replacement trees, and select 2 to 5 main branches with branch angles of 100° to 150°, straight and smooth trunks, strong production, no diseases and insect pests, and stem diameters of 2 to 6 cm from each oil tea tree as high-graft replacement rootstocks; S3, collecting and storing spikelets: Spikelets are collected by strain, and semi-lignified branches of the current year with full development, full axillary buds, strong growth, and no diseases and insect pests are selected; Spikelets are collected in the morning, bundled by variety after collection, labeled, wetted with clean water and placed in plastic bags, the accumulated water in the plastic bags is drained, wet cotton balls are placed in the bags and the bags are tied tightly; the collected spikelets are sealed and stored in a cool and ventilated place or the roots of the spikelets are inserted into moist soil under the shade of trees for storage; S4. Start grafting: S4.1, cutting and trimming the stock: saw off the main branches of the selected stock at 40 to 80 cm from the ground. Avoid tearing the bark of the stock during sawing. Leave a few main branches on the tree to support the shade net later. Except for the branches left as nutrient branches, remove all other branches and weeds on the ground near the tree. Avoid leaving stumps when pruning. When trimming the stock, trim the saw cut surface to make it smooth and flat. S4.2. Cutting the buds: Cut the buds into 5-6 cm segments, with at least one lateral bud in each segment. Cut off half of the leaves on the buds to reduce evaporation and maintain photosynthesis of the scion. When cutting the buds, cut a 2-3 cm long bevel 1 cm below the other side of the bud. The cutting depth should be slightly enough to see the cut surface of the wood, and the pith should be visible at the base. Keep the cut surface smooth. Cut a short bevel less than 1 cm below the side where the bud is located. Cut the scion above the bud. Use the scion as soon as possible after cutting. Keep the buds moist while they are waiting to be used. S4.3, cutting the rootstock: According to the size and length of the scion, select a smooth part on the edge of the wood of the rootstock section and make a straight cut down to the edge of the wood, then lift the skin to the left and pull it apart; S4.4, Scion: Align the long cut surface of the scion with the stock and insert it into the skinning groove, align the cambium on one side, make the cut surface of the scion higher than the cross section of the stock, and then cover the skin of the stock on the short cut surface of the scion; S4.5, Binding: Use PVC black tape with good elasticity, strong tension and a width of 1.0 ~ 2.0cm to bind the scion from bottom to top in a counterclockwise direction. When binding, tighten the film strip to prevent the scion from moving; S4.6, Bagging: After the stock is tied, immediately put on a white transparent plastic bag. The size of the bag depends on the thickness of the stock and the number of scions. The flat size is 12 to 15 cm long and 6 to 9 cm wide. The bag mouth should be tied to keep warm and moisturize. S4.7, Shading: Shade the grafted plants in a place with strong sunlight. The shading area is about 1.5 ^m2 and the shading height is more than 15 cm from the grafted buds. S5. Post-grafting management: S5.1. Bag replacement: After grafting, check whether the white transparent plastic bag at the grafting site is damaged at any time. If the bag is found to be leaking, it should be replaced in time. S5.2, bag removal: When the spike buds grow to more than 2 cm and fill the white transparent plastic bag, gradually remove the bag in the evening of cloudy or sunny days. After removing the bag, shade is still provided for 1 to 2 weeks to allow the sprouting axillary buds to gradually adapt to the natural environment. During this stage, attention should be paid to the damage of aphids, green cicadas, and beetles to the tender shoots. If pests or diseases are found, spray pesticides in time; S5.3. Removal of shading materials: When the grafted axillary buds grow to September and the grafted buds are more than 10 cm long, remove the shading materials on a cloudy day or in the evening; at the same time, cut off all branches and sprouts except the grafted buds to prevent them from competing with the grafted buds for water and fertilizer, so that the grafted buds can continue to grow in autumn and increase their growth; S5.4, pruning and removing sprouts: timely remove the sprouts on the grafted tea oil rootstock, and keep the sprouts on the grafted rootstock that has not survived, and remove the previously retained nutrient branches with pruning shears or saws before the temperature drops in autumn and winter; in addition, pruning should be carried out before the spring shoots in the second year after grafting, and the cross branches and branches growing inward should be pruned to make the crown develop evenly and form a reasonable tree shape. No stumps should be left when removing sprouts and pruning, that is, the pruned branches should be cut from the base; S5.5, Unbinding: In the winter of the current year or the spring of the following year, remove the tape after the new shoots have grown strong; S5.6. Weeding and fertilization: Cut weeds and till the land to 15 to 22 cm every year. Dig and fertilize in the winter of the current year and the spring of the following year. Apply 0.5 kg of special fertilizer for oil tea to each plant each time. 2. The method for high-grafting and replacing oil-tea camellia according to claim 1 is characterized in that: in S3, the scion strips are generally used as soon as they are picked, and are sealed and stored in a cool and ventilated place including a cellar or a cool room for 3 to 5 days. If the temperature is too high or the storage time is more than 5 days, they should be stored in a refrigerator. 3. A method for high grafting and replacing oil-tea camellia according to claim 1, characterized in that: in S4.1, in addition to the main branches left as the rootstock, 2 to 3 main branches are retained as nutrient branches for transpiration and photosynthesis, and 1 main branch is retained to support the sunshade net to achieve shading; when cutting the rootstock, the side close to the main branch of the rootstock is required to be higher inside and slightly lower on the outer edge, and the inclination angle of the inner and outer sides is 5° to 15°. 4. The method for high grafting of tea oil plants according to claim 1 is characterized in that: in S4.4, 1 to 3 scions are grafted on one rootstock, and the number of scions is determined according to the stem diameter of the rootstock. 5. The method for high-grafting and replacing tea oil trees according to claim 1 is characterized in that: in S4.6, a plastic rope is used to tie the mouth of the white transparent plastic cover bag with a loose knot, and the binding should not be too tight or too loose to ensure that the sap can flow out easily after the cover bag is tied, and at the same time the cover bag can be stably fixed. When tying the cover bag or after the tying is completed, the shape of the cover bag is adjusted to avoid affecting the growth of the scion. 6. A method for high-grafting and replacing tea oil trees according to claim 1 is characterized in that: in S4.7, the thickened black agricultural sunshade net is propped up by using the sharpened thin bamboo poles and the higher trunk reserved in the middle of the tree body to achieve shading; wherein, the bamboo poles are vertically inserted into the soil to ensure the firmness of the sunshade net to avoid being blown down by wind and rain, and when the thickness of a single-layer sunshade net is relatively thin, the sunshade net is folded into two layers for use to achieve the best shading effect. 7. The method for high-grafting and replacing oil-tea camellia according to claim 1 is characterized in that: in S5.1, pesticides are sprayed on the outside of the white transparent plastic cover bag to prevent planthoppers and ants from eating the cover bag. 8. The method for high-grafting and replacing oil-tea trees according to claim 1 is characterized in that: in S5.5, when the growth of new shoots is poor, the tape is first slightly scratched and not completely untied, and then the tape is completely removed when the new shoots grow more robustly.