Spring grafting method for peony

Abstract

This invention discloses a spring grafting method for peonies, belonging to the field of peony grafting technology. It includes the following steps: S1. In early spring, one-year-old branches with healthy dormant flower buds are cut from peonies as scions and then sealed; S2. The sealed scions are frozen at -18℃ to -25℃. 12-16 hours before grafting, the frozen scions are taken out, first placed at 2℃-5℃ for 2-4 hours to warm up, and then placed at room temperature for 10-14 hours; S3. The warmed scions are wax-sealed; S4. Ten days before / after the vernal equinox, when the average daily temperature is stable above 15℃, the wax-sealed scions are grafted onto peony rootstock using the ground-digging grafting method; S5. The grafted plants are promptly and completely covered with soil. This invention organically integrates multiple steps, including scion collection timing, low-temperature preservation, gradient warming, scion pretreatment, and specific grafting operations, breaking the time restriction that peonies can only be grafted in autumn and enabling spring grafting.

Description

Technical Field

[0001] This invention relates to the field of peony grafting technology, and more particularly to a spring grafting method for peonies. Background Technology

[0002] The information disclosed in the background section of this invention is intended only to enhance the understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] Traditional peony propagation mainly relies on grafting, and the industry-recognized best time for grafting is autumn, usually from mid-September to mid-October. The soil temperature during this period (about 23°C) is most conducive to callus formation and graft union healing between the scion and rootstock, thus ensuring a high survival rate.

[0004] In autumn grafting practices, it is usually necessary to dig up the rootstock (such as peony or peony seedlings) from the soil and perform grafting in an indoor or semi-indoor environment, after which the grafted parts are buried or planted. This operation mode highly overlaps with the peak sales season for peony seedlings in autumn. However, in the seedling production process, after winter, a large number of 2-3 year old peony seedlings often remain unsold. To encourage these seedlings to sprout more branches in the following spring, producers usually perform coppicing in winter, that is, pruning all the above-ground branches. These coppiced branches, having missed the autumn grafting period and lacking effective preservation methods, are often disposed of as waste, resulting in a great waste of high-quality germplasm resources.

[0005] Therefore, developing a method that can effectively utilize winter-cut branches and successfully graft in spring, in addition to the existing autumn grafting technology system, is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0006] In view of this, the present invention provides a spring grafting method for peonies, breaking the time restriction that peonies can only be grafted in autumn and realizing spring grafting.

[0007] In a first aspect, the present invention provides a method for spring grafting of peonies, comprising the following steps: S1. In early spring, take one-year-old branches with healthy dormant flower buds from peonies as scions, and then seal them. S2. Place the sealed scions in a freezer at -18℃ to -25℃. 12-16 hours before grafting, take out the frozen scions, first place them at 2℃-5℃ to warm up for 2-4 hours, and then place them at room temperature to warm up for 10-14 hours. S3. After the scions have been warmed up, they are sealed with wax. S4. Ten days before / after the vernal equinox, when the average daily temperature is stable above 15℃, use the ground-digging inlay method to graft wax-sealed scions onto peony rootstocks. S5. After grafting, the plant should be completely covered with soil in time.

[0008] Preferably, in S1, the scion is 7-12cm long and has one terminal bud and 1-2 lateral buds.

[0009] Preferably, in S2, the room temperature is 15℃-25℃.

[0010] Preferably, in S3, during wax sealing, the scion is completely immersed in the molten paraffin liquid and immediately removed; During wax sealing, the temperature of the molten paraffin liquid is maintained at 60-80℃.

[0011] Preferably, in S4, the ground grafting method specifically involves: digging up the soil around the roots of the rootstock in the rootstock cultivation site to expose the root neck; removing the buds and dormant buds above the root neck; shaping the lower end of the wax-sealed scion into a three-sided pointed tip with one side covered with bark; making a longitudinal cut from the top of the rootstock downwards to a depth of 2 / 3 of the rootstock; aligning the thinner edge of the scion with the cut and inserting it so that the cut surfaces of the rootstock and scion match; and fixing it with binding material.

[0012] Preferably, in S4, the rootstock is a robust 2-3 year old peony seedling, and the soil is dug to a depth of 10-15 cm.

[0013] Preferably, in S4, the triangular tip at the lower end of the scion is formed by making a symmetrical oblique cut on each side 2-3 cm from the lower end of the scion.

[0014] Preferably, in S4, the longitudinal length of the cut is slightly longer than the cut surface of the scion by 2-3 mm.

[0015] Preferably, in S4, the binding material is thin hemp rope, and the joint is tightened from top to bottom during binding.

[0016] Preferably, in S5, the soil covering thickness extends 5-10cm above the bud at the tip of the scion, forming a mound.

[0017] Compared with the prior art, the present invention has achieved the following beneficial effects: (1) The spring grafting method for peonies provided by this invention organically integrates multiple steps, including the timing of scion collection, low-temperature preservation, gradient temperature recovery, scion pretreatment, and specific grafting operations, successfully breaking through the seasonal limitations of peony grafting. First, this invention collects scions when the temperature is about to rise significantly in early spring and uses low-temperature freezing to preserve the scions, allowing them to maintain a deep dormancy state after being separated from the parent plant. Grafting is then carried out under suitable environmental conditions in late March, breaking the time restriction that peonies can only be grafted in autumn, thus realizing spring grafting, extending the grafting window, and improving the flexibility of grafting operations. This not only effectively solves the problem of discarded peony branches after winter coppicing and realizes the reuse of germplasm resources, but also provides a more flexible time arrangement for peony production. Secondly, the three-stage gradient warming program of "freezing → low temperature refrigeration → room temperature" adopted in this invention provides a stable physiological transition for the scion after freezing and avoids irreversible damage to the scion cells caused by sudden temperature changes. This ensures that the scion can maintain good physiological activity and does not sprout prematurely after being completely thawed and before grafting, laying the foundation for subsequent grafting healing.

[0018] (2) This invention has systematically optimized the grafting process. First, the scions are wax-sealed after warming up to form a dense protective film, effectively preventing the evaporation and loss of moisture from the scions. Second, the "ground grafting" method is used, grafting is performed directly in the original growing area of ​​the rootstock, avoiding secondary damage to the root system caused by transplanting. During the grafting process, precise alignment and tight binding of the cambium layers create favorable conditions for the physical healing of the interface. Most importantly, the grafted plant is promptly and completely sealed with soil. This crucial operation creates a dark, humid, and relatively stable microenvironment around the interface, greatly promoting the rapid formation of callus tissue and perfect healing of the interface, while effectively resisting the invasion of adverse weather conditions such as "late spring frost". It is the synergistic effect of the above steps that enables the peony grafting survival rate of this invention to reach over 90%, realizing the large-scale application of spring grafting. Attached Figure Description

[0019] The accompanying drawings, which form part of this specification, are used to provide a further understanding of the invention. The illustrative embodiments and descriptions of the invention are used to explain the invention and do not constitute an undue limitation thereof. Obviously, those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0020] Figure 1 This is a photograph of the peony scion in Embodiment 1 of the present invention; Figure 2 This is a photograph of the peony scion in Embodiment 1 of the present invention; Figure 3 These are photographs of the soil excavated on both sides of the rootstock in Embodiment 1 of the present invention; Figure 4 This is a photograph of the cutting of the scion in Embodiment 1 of the present invention; Figure 5 This is a photograph of the cutting of the scion in Embodiment 1 of the present invention; Figure 6 This is a photograph of the cut surfaces of the rootstock and scion fitting together in Embodiment 1 of the present invention; Figure 7 This is a photograph of the thin hemp rope binding in Embodiment 1 of the present invention; Figure 8 This is a photograph of the soil mound in Embodiment 1 of the present invention; Figure 9 This is a photograph of the grafted plant sprouting from the soil in Embodiment 1 of the present invention; Figure 10 This is a photo of a peony successfully grafted and growing naturally, as shown in Example 1 of this invention. Detailed Implementation

[0021] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0022] This invention provides a spring grafting method for peonies, comprising the following steps: S1. In early spring, take one-year-old branches with healthy dormant flower buds from peonies as scions, and then seal them. S2. Place the sealed scions in a freezer at -18℃ to -25℃. 12-16 hours before grafting, take out the frozen scions, first place them at 2℃-5℃ to warm up for 2-4 hours, and then place them at room temperature to warm up for 10-14 hours. S3. After the scions have been warmed up, they are sealed with wax. S4. Ten days before / after the vernal equinox, when the average daily temperature is stable above 15℃, use the ground-digging inlay method to graft wax-sealed scions onto peony rootstocks. S5. After grafting, the plant should be completely covered with soil in time.

[0023] Specifically, in S1, scions are collected in early spring when temperatures are about to rise significantly. At this time, the flower buds are in a critical state of ending dormancy and about to sprout. Selecting one-year-old branches with healthy dormant flower buds ensures that the scions have sufficient growth potential and facilitates subsequent preservation and grafting operations. Sealing prevents moisture loss from the scions, maintains their physiological activity, and lays the foundation for subsequent preservation and grafting.

[0024] Furthermore, the criteria for judging healthy dormant flower buds are: observe the state of the flower buds, and when the flower buds gradually become plump from their shriveled state during dormancy, and the bud scales turn from dry to bright, it is the best time to cut them.

[0025] Specifically, in S2, the sealed scions are frozen at -18℃ to -25℃, which keeps them in a deep dormant state, effectively extending their storage time and preventing deterioration due to physiological activity outside the grafting season. This solves the problem of winter-cut branches not being able to be preserved for spring grafting. Furthermore, a three-stage gradient warming procedure of "freezing → low-temperature refrigeration → room temperature" provides a stable physiological transition for the frozen scions. First, they are warmed at 2℃-5℃ for 2-4 hours, allowing the scions to slowly warm from their frozen state, avoiding irreversible damage to the scion cells caused by sudden temperature changes. Then, they are warmed at room temperature for 10-14 hours, allowing the scions to further adapt to the ambient temperature. This ensures that the scions maintain good physiological activity and do not prematurely sprout after complete thawing and before grafting, laying the foundation for subsequent grafting healing.

[0026] Specifically, the scions are wax-sealed after being warmed up, forming a dense protective film on the surface of the scion, which effectively prevents the evaporation and loss of moisture. In the relatively dry environment of spring, wax sealing can maintain the moisture content of the scion, preserve its physiological activity, and improve the survival rate of the scion after grafting.

[0027] Specifically, in the ten days before and after the vernal equinox, the average daily temperature remains stable above 15℃. At this time, the environmental conditions are suitable, which is conducive to callus formation and graft union healing between the scion and rootstock. Furthermore, using the in-situ grafting method, grafting is performed directly in the original growing location of the rootstock, avoiding secondary damage to the root system caused by transplanting, reducing interference with the rootstock and scion during the grafting process, and thus improving the grafting survival rate.

[0028] Specifically, after grafting, the plant is immediately and completely covered with soil, creating a dark, humid, and relatively stable microenvironment around the graft union. This microenvironment greatly promotes the rapid formation of callus tissue and perfect healing of the graft union, while effectively resisting the invasion of adverse weather conditions such as late spring frosts, providing favorable conditions for the survival and growth of the scion, and improving the grafting survival rate.

[0029] In an optional embodiment of the present invention, in S1, the scion is 7-12 cm long and has one terminal bud and 1-2 lateral buds.

[0030] Specifically, limiting the length of the scion and the number of buds within this range is based on considerations of ease of grafting and post-grafting growth vigor. Scions that are too short are difficult to fix and bury in soil, while scions that are too long increase the burden of water transpiration. Retaining one terminal bud and 1-2 lateral buds ensures that the scion has sufficient vitality and can form a good plant shape after survival, making it the optimal solution for balancing grafting survival rate and later growth potential.

[0031] In an optional embodiment of the present invention, in S2, the room temperature is 15°C-25°C.

[0032] Specifically, in the gradient warming process, the room temperature is limited to a natural range of 15℃-25℃ to simulate normal spring temperatures, allowing the physiological activities of the scion to recover gradually and naturally. This temperature range ensures that the scion thaws fully while preventing premature budding due to excessively high temperatures, thus controlling the scion's state to the optimal condition of being awakened but not yet sprouting before grafting.

[0033] In an optional embodiment of the present invention, in S3, during wax sealing, the scion is completely immersed in the molten paraffin liquid and immediately removed; During wax sealing, the temperature of the molten paraffin liquid is maintained at 60-80℃.

[0034] Specifically, controlling the temperature of the paraffin wax solution during impregnation at 60-80℃ is crucial for achieving the best wax sealing effect. If the temperature is too low, the wax solution has poor fluidity, resulting in a thick but uneven wax film that may not even completely cover the graft; if the temperature is too high, it may scald the buds and cortex of the scion, causing irreversible damage. This temperature range ensures a thin, uniform, and dense wax film without heat damage to the scion, making it the core process parameter for guaranteeing the wax sealing effect.

[0035] In an optional embodiment of the present invention, in S4, the ground grafting method specifically involves: digging up the soil around the roots of the rootstock in the rootstock cultivation site to expose the root neck; removing the buds and dormant buds above the root neck; shaping the lower end of the wax-sealed scion into a three-sided pointed tip with one side covered with bark; making a longitudinal cut from the top of the rootstock downwards to a depth of 2 / 3 of the rootstock; aligning the thinner edge of the scion with the cut and inserting it so that the cut surfaces of the rootstock and scion match; and fixing it with binding material.

[0036] Specifically, the operation process of the ground-digging grafting method is refined, clarifying the complete steps from rootstock soil excavation, bud treatment, scion cutting, incision cutting to scion embedding and binding. This makes the grafting operation more standardized and operable, avoiding problems such as misalignment of the cambium layers of the scion and rootstock and loosening of the interface caused by non-standard operation. At the same time, it ensures that the scion and rootstock are closely attached, promotes callus formation, and improves the interface healing efficiency and grafting survival rate.

[0037] In an optional embodiment of the present invention, in S4, the rootstock is a healthy 2-3 year old peony seedling, and the soil is dug to a depth of 10-15 cm.

[0038] Specifically, 2-3 year old peony seedlings are selected as rootstock because they have well-developed root systems and strong growth, providing sufficient nutrients and water for the scion. The digging depth is controlled at 10-15cm, which fully exposes the root collar for easy operation without excessively damaging the root system, allowing it to quickly recover its absorption function after grafting and ensuring scion survival.

[0039] In an optional embodiment of the present invention, in S4, the triangular tip at the lower end of the scion is formed by making a symmetrical oblique cut on each side 2-3 cm from the lower end of the scion.

[0040] Specifically, by making symmetrical oblique cuts on both sides 2-3cm below the scion, a smooth and regular cut surface can be formed, allowing the scion and rootstock cuts to fit together better. In particular, the structure design with bark on one side can accurately align the cambium layers of the scion and rootstock, promoting healing between the two, while avoiding problems such as scion damage and loose joints caused by improper cutting methods, further improving the grafting survival rate.

[0041] In an optional embodiment of the present invention, in S4, the longitudinal length of the cut is slightly longer than the cut surface of the scion by 2-3 mm.

[0042] Specifically, the length of the rootstock cut is set to be slightly longer than the cut surface of the scion by 2-3 mm, leaving a small space for the scion to be inserted. This length setting allows the scion to be better inserted into the rootstock cut, ensuring that the two are tightly bonded, increasing the contact area of ​​the cambium, promoting callus formation, and improving the grafting success rate.

[0043] In an optional embodiment of the present invention, in S4, the binding material is a thin hemp rope, and the joint is tightened from top to bottom during binding.

[0044] Specifically, the fine hemp rope is soft and breathable, which can not only firmly fix the joint between the scion and the rootstock to prevent the joint from loosening, but also avoid damage to the scion and rootstock tissues; the top-down binding method can ensure that the joint is evenly stressed, further improving the fit between the scion and the rootstock and promoting the healing of the joint.

[0045] In an optional embodiment of the present invention, in S5, the soil covering thickness extends 5-10 cm above the bud at the tip of the scion, forming a soil mound.

[0046] Specifically, this soil covering thickness provides a good environment for heat preservation and moisture retention at the graft union, preventing moisture evaporation from the scion and the influence of adverse external factors. At the same time, it ensures that the buds at the top of the scion have enough space to grow, which is beneficial to the survival and growth of the grafted plant.

[0047] The technical solution of the present invention will be further described below with reference to specific embodiments. Unless otherwise specified, the technical means used in the embodiments are conventional means well known to those skilled in the art.

[0048] Example 1 This embodiment provides a spring grafting method for peonies, specifically including the following steps: (1) Scion collection and sealing On February 10, 2025 (before the local temperature rises significantly), observe the bud condition of the 'Shimajin' peony. When the buds gradually become plump from a shriveled state, and the bud scales turn from dry to bright, select healthy one-year-old branches as scions. The scion length should be controlled to 8-10cm, with each scion having one terminal bud and 1-2 lateral buds (see [link to scion description]). Figure 1-2 After cutting, quickly place the scions into a sealed plastic bag.

[0049] (2) Scion cryopreservation and gradient thawing Immediately place the sealed scions in a -21°C freezer for 37 days (from February 10 to March 19). Sixteen hours before the scheduled grafting date (18:00 on March 19), remove the frozen scions: first place them in a 3°C refrigerated environment to thaw for 3 hours (until 21:00 on March 19); then place them in a 20°C room temperature environment to thaw for 13 hours (until 10:00 on March 20), allowing the scions to fully thaw and show no signs of sprouting.

[0050] (3) Scion wax sealing treatment After the thawing process is complete, the scions are removed and wax-sealed. The paraffin wax is heated to 70°C and melted. The scions are then quickly immersed in the molten paraffin wax and immediately removed, so that a uniform and dense sealing wax film is formed on the surface of the scions.

[0051] (4) Grafting by digging and embedding The best time for grafting is on the spring equinox (March 20th), when the average daily temperature is consistently above 15℃, and grafting should be done on a sunny day.

[0052] Select healthy 2-year-old peony seedlings as rootstock. In their planting site, dig soil around the rootstock to a depth of 12cm on both sides, exposing the entire root collar (see...). Figure 3 Remove all buds and dormant buds above the root collar of the rootstock.

[0053] 2.5cm below the wax-sealed scion, make two symmetrical oblique cuts on each side with a grafting knife to create a three-sided pointed tip with one side still bearing the bark (see [link]). Figure 4-5 Make a vertical cut from the top of the rootstock downwards using a grafting knife. The cut should be 2 / 3 the diameter of the rootstock and slightly longer than the cut surface of the scion by 2.5 mm.

[0054] Insert the thinner ridge of the scion (the ridge without bark) into the incision on the rootstock, ensuring a tight fit between the cut surfaces of the rootstock and scion, and guaranteeing cambium alignment (see [link]). Figure 6 After aligning, use thin hemp rope to tie the joint tightly from top to bottom (see...). Figure 7 ).

[0055] After grafting and binding, immediately cover and compact the entire graft union and scion with the excavated, fine, moist soil, forming a mound. The soil covering should extend 7cm above the top bud of the scion (see [reference]). Figure 8 ).

[0056] (5) Post-operative management and survival statistics Regular observations were conducted after grafting. On April 12, 2025 (approximately 23 days after grafting), it was observed that the buds at the tips of the scions began to sprout from the soil (see [link to relevant documentation]). Figure 9-10 On May 12, 2025 (approximately 53 days after grafting), the survival rate was checked and found to be 93% (93 / 100).

[0057] Example 2 This embodiment provides a spring grafting method for peonies, which is basically the same as that in Embodiment 1, except for the selection of some parameters, as follows: (1) Scion collection and sealing On February 15, 2025, the 'Huangguan' peony flower buds were observed to confirm the optimal time for cutting, and scions were then cut. The length of the scions was controlled to be 7-9cm, and each scion had one terminal bud and 1-2 lateral buds.

[0058] (2) Scion cryopreservation and gradient thawing The sealed scions were frozen at -18°C for 32 days. 14 hours before the scheduled grafting date (March 18, 20:00), the frozen scions were taken out: first, they were placed in a 5°C low-temperature refrigeration environment to warm up for 2 hours (until March 18, 22:00); then, they were placed in a 22°C room temperature environment to warm up for 12 hours (until March 19, 10:00).

[0059] (3) Scion wax sealing treatment The paraffin wax is heated to 65°C and melted before being sealed with wax.

[0060] (4) Grafting by digging and embedding The grafting should be done 3 days before the vernal equinox (March 17th), when the average daily temperature is stable at 16℃. Select a healthy 3-year-old peony seedling as the rootstock and dig it to a depth of 10cm. Make the cut 2cm below the scion, with the cut slightly longer than the cut surface by 2mm, and cover it with 6cm of soil.

[0061] (5) Post-operative management and survival statistics On April 10, 2025, scion buds were observed to emerge from the soil. On May 10, 2025, the survival rate was checked and the survival rate was 90% (90 / 100).

[0062] Example 3 This embodiment provides a spring grafting method for peonies, which is basically the same as that in Embodiment 1, except for the selection of some parameters, as follows: (1) Scion collection and sealing On February 15, 2025, the 'Shimajin' peony flower buds were observed to confirm the optimal time for cutting, and scions were then cut. The length of the scions was controlled to be 10-12cm, and each scion had one terminal bud and 1-2 lateral buds.

[0063] (2) Scion cryopreservation and gradient thawing The sealed scions were frozen at -25°C for 33 days. Twelve hours before the scheduled grafting date (March 19, 22:00), the frozen scions were removed: first, they were placed in a 2°C low-temperature refrigeration environment to warm up for 4 hours (until March 20, 2:00); then, they were placed in a 18°C ​​room temperature environment to warm up for 8 hours (until March 20, 10:00).

[0064] (3) Scion wax sealing treatment The paraffin wax is heated to 75°C and melted before being sealed with wax.

[0065] (4) Grafting by digging and embedding The grafting should be done 5 days after the vernal equinox (March 25th), when the average daily temperature is stable at 18℃. Select healthy 2-year-old peony seedlings as rootstock and dig to a depth of 15cm. Make the cut 3cm below the scion, with the longitudinal length of the cut slightly longer than the cut surface by 3mm, and cover with 9cm of soil.

[0066] (5) Post-operative management and survival statistics On April 18, 2025, scion buds were observed to emerge from the soil. On May 18, 2025, the survival rate was checked and found to be 91% (91 / 100).

[0067] The statistical results of Examples 1-3 above are summarized in Table 1 below.

[0068] Table 1 Statistical results of Examples 1-3

[0069] The above results show that, within the parameter range defined by this invention, different parameter combinations can achieve a high survival rate of over 90%, verifying the stability and repeatability of the technical solution of this invention.

[0070] Comparative Example 1 This comparative example provides a spring grafting method for peonies, which is basically the same as Example 1, except that in step S2, after sealing, the peony is first dried and then frozen for preservation. Details are as follows: (1) Scion collection and sealing On February 10, 2025, 'Island Brocade' peony scions were cut using the same method as in Example 1. The scions were 8-10 cm long, with one terminal bud and 1-2 lateral buds, and were placed in a plastic sealed bag.

[0071] (2) Drying and freezing of scions Open the sealed bag and allow it to air dry naturally at room temperature (20℃) and 40% relative humidity for 6 hours. This allows the surface moisture of the scion to evaporate and slightly shrink. Reseal the bag and freeze it at -21℃ for 37 days. Sixteen hours before the scheduled grafting date (March 19th, 18:00), remove the frozen scions: first, thaw them at 3℃ for 3 hours; then, thaw them at room temperature (20℃) for 13 hours.

[0072] (3) The scion wax sealing treatment is the same as in Example 1.

[0073] (4) Grafting by digging and embedding is the same as in Example 1.

[0074] (5) Post-operative management and survival statistics Observations were conducted from April 12th to April 20th, 2025. Only a few buds at the tips of the scions sprouted, while most scions failed to sprout. A survival check was conducted on May 12th, 2025, revealing a survival rate of only 12% (12 / 100). Observations showed that most of the non-surviving scions exhibited signs of drying and wrinkling, indicating that the drying process caused excessive water loss and loss of cell vitality before freezing. Even subsequent wax sealing and soil sealing treatments could not restore their physiological activity.

[0075]

[0076] Table 2 Comparison of results between Comparative Example 1 and Example 1 As shown in Table 2, sealing and timely freezing of the scions is a crucial prerequisite for ensuring scion viability. If a drying step is added between sealing and freezing, the scions will suffer cell damage due to water loss. Even with subsequent gradient warming, wax sealing, in-situ grafting, and soil sealing operations, the scion viability cannot be salvaged, and the survival rate will be significantly reduced. This underscores the necessity and technological contribution of the "immediate sealing and freezing after cutting" operation in this invention.

[0077] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A spring grafting method for peonies, characterized in that, Includes the following steps: S1. In early spring, take one-year-old branches with healthy dormant flower buds from peonies as scions, and then seal them. S2. Place the sealed scions in a freezer at -18℃ to -25℃. 12-16 hours before grafting, take out the frozen scions, first place them at 2℃-5℃ to warm up for 2-4 hours, and then place them at room temperature to warm up for 10-14 hours. S3. After the scions have been warmed up, they are sealed with wax. S4. Ten days before / after the vernal equinox, when the average daily temperature is stable above 15℃, use the ground-digging inlay method to graft wax-sealed scions onto peony rootstocks. S5. After grafting, the plant should be completely covered with soil in time.

2. The spring grafting method for peonies as described in claim 1, characterized in that, In S1, the scion is 7-12cm long and has one terminal bud and 1-2 lateral buds.

3. The spring grafting method for peonies as described in claim 1, characterized in that, In S2, the room temperature is 15℃-25℃.

4. The spring grafting method for peonies as described in claim 1, characterized in that, In S3, during wax sealing, the scion is completely immersed in the molten paraffin wax and then immediately removed; During wax sealing, the temperature of the molten paraffin liquid is maintained at 60-80℃.

5. The spring grafting method for peonies as described in claim 1, characterized in that, In S4, the ground grafting method specifically involves: digging up the soil around the roots of the rootstock in the rootstock cultivation site to expose the root neck; removing the buds and dormant buds above the root neck; shaping the lower end of the wax-sealed scion into a three-sided pointed tip with one side covered with bark; making a vertical cut from the top of the rootstock downwards to a depth of 2 / 3 of the rootstock; inserting the thinner edge of the scion into the cut so that the cut surfaces of the rootstock and scion match, and fixing it with binding material.

6. The spring grafting method for peonies as described in claim 5, characterized in that, In S4, the rootstock is a robust 2-3 year old peony seedling, and the soil is dug to a depth of 10-15 cm.

7. The spring grafting method for peonies as described in claim 5, characterized in that, In S4, the triangular tip at the lower end of the scion is formed by making a symmetrical oblique cut on each side 2-3 cm from the lower end of the scion.

8. The spring grafting method for peonies as described in claim 5, characterized in that, In S4, the longitudinal length of the cut is slightly longer than the cut surface of the scion by 2-3 mm.

9. The spring grafting method for peonies as described in claim 5, characterized in that, In S4, the binding material is thin hemp rope, and the joint is tightened from top to bottom during binding.

10. The spring grafting method for peonies as described in claim 1, characterized in that, In S5, the soil covering should extend 5-10cm above the bud at the top of the scion, forming a mound.

Images