A method for promoting cultivation by using natural low temperature to break the sleep of paeonia lactiflora

Abstract

The application relates to the cultivation field of paeonia, and discloses a method for promoting cultivation of paeonia by breaking sleep with natural low temperature, which comprises the following steps: planting paeonia in a sunlight greenhouse in autumn, planting for years at a time; breaking sleep of the paeonia by using natural low temperature in autumn and winter, assisting with a temperature-keeping and light-shielding cotton quilt for daytime covering, and removing the cotton quilt and ventilating at night; according to the cold requirement of different varieties, the natural low temperature breaking sleep treatment is carried out for 45-70 days, and water is not supplemented during the period; after the sleep breaking, the temperature is naturally increased by using solar radiation, and the day and night temperature is regulated and controlled through ventilation and temperature-keeping measures, the whole process does not need artificial light supplement, and growth period management is assisted. The light is blocked by covering the cotton quilt with high light shielding rate during the day, the cotton quilt is removed and ventilated at night, the ground surface temperature is controlled to be less than or equal to 7.5 DEG C, the paeonia naturally accumulates the cold requirement in the open ground environment, does not need to depend on the cold storage equipment and artificial low temperature environment, the energy consumption and facility cost are greatly reduced, and the green environmental protection concept is met.

Description

Technical Field

[0001] This invention relates to the field of peony cultivation, specifically a method for promoting the cultivation of peonies by utilizing natural low temperatures to break dormancy. Background Technology

[0002] Peony, as a traditional famous flower in my country, has significant importance in the flower market due to its forcing cultivation techniques. Currently, techniques for breaking dormancy and regulating flowering in peonies have significant limitations: On the one hand, traditional methods rely on cold storage to meet their chilling requirements, inducing buds to break dormancy through low temperatures. However, cold storage facilities are expensive to build and operate, energy-intensive, and limited by equipment capacity when used on a large scale, making operation cumbersome and management difficult. On the other hand, some techniques combine open-field cultivation with hormone treatment. For example, after planting in the open field, seedlings are dug up and their roots are treated with hormone solutions such as gibberellin (GA3) to break dormancy before being transferred to pots and then to greenhouses for cultivation. However, these methods still have several drawbacks:

[0003] During the process of transplanting peony seedlings from open fields to pots, the limited space in the pot restricts the natural expansion of the fleshy roots, leading to decreased root nutrient absorption efficiency and problems such as limited plant height and poor flower diameter development. Simultaneously, the potting mix may experience localized nutrient imbalances or compaction, affecting root development and reducing plant vigor. Furthermore, while hormone treatment can temporarily break dormancy and advance flowering, gibberellins promote excessive vegetative growth in the above-ground parts and inhibit underground root development, causing nutrient imbalances and resulting in weak flower stems, lodging, and even decreased survival rates. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a method for promoting the cultivation of peony by naturally breaking dormancy at low temperatures, which solves the problems of high cost, high risk, and unstable quality in existing technologies.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] The first aspect of this invention provides a method for forcing peony cultivation by utilizing natural low-temperature breaking of dormancy, suitable for application in the cold regions of Northwest and Northeast China.

[0007] This method is applied to greenhouses equipped with heat-insulating and light-blocking blankets, ventilation systems, and irrigation systems, and includes the following steps:

[0008] Step 1 (S1): Planting in open field in a solar greenhouse.

[0009] In early October each year, under conditions of ambient temperature of 10-20℃, peony seedlings are transplanted into open fields. The spacing between plants and rows is set at 30-50cm × 50-70cm, with a ridge height of 30-40cm. Before transplanting, the peony seedlings are sterilized by adding sulfur powder to the soil for sterilization and alkalinity reduction, and well-rotted organic fertilizer is applied as base fertilizer. After transplanting, the soil is thoroughly watered once to ensure full contact between the seedlings and the soil. The technical concept behind this step is that a single transplanting allows for continuous harvesting for several years, reducing the labor costs and soil disturbance associated with annual tilling and transplanting. During the subsequent growth cycle of the seedlings, irrigation water is strictly controlled to maintain a low soil moisture level. This is to avoid the root system being in an anaerobic environment due to excessive soil moisture, thereby reducing the risk of root rot.

[0010] In one specific implementation, the peony seedlings are selected from 3-4 year old seedlings, characterized by 3-5 plump underground buds per plant, without mechanical damage. The seedlings must pass quarantine to confirm they are free from peony root-knot nematodes and gray mold quarantine pests.

[0011] As one specific implementation method, the sterilization treatment is carried out by placing the peony seedlings in a carbendazim fungicide solution diluted 800-1000 times with water and soaking for 10-20 minutes.

[0012] Step 2 (S2): Natural low-temperature sleep breaking treatment.

[0013] When the nighttime outside temperature can stably drop below 7.5℃, the dormancy-breaking treatment begins. From 09:00 to 17:00 daily, the greenhouse is covered with insulating and shading blankets to block daytime solar radiation and inhibit the rise in surface temperature. From 17:00 to 09:00 the following day, the insulating and shading blankets are removed, and the ventilation openings at the bottom of the greenhouse are opened to allow cold outside air to enter the greenhouse and directly affect the ground surface. Surface temperature data is acquired in real time using surface temperature monitoring equipment, and the temperature is ensured to be controlled within the range of ≤7.5℃. This low-temperature treatment lasts for 45-70 days. The core technology of this step is to utilize the natural low nighttime temperatures in Northwest and Northeast my country during winter as a cold source, replacing the artificial low-temperature environment generated by refrigeration equipment in traditional forcing cultivation, greatly reducing energy consumption and equipment investment. Throughout the entire low-temperature treatment cycle, all irrigation and watering operations are stopped to maintain the soil's dryness, simulating the winter dormancy environment of peonies under natural conditions.

[0014] As one specific implementation, the light-blocking rate of the heat-insulating and light-blocking cotton quilt is not less than 90% to ensure effective blocking of daytime solar radiation.

[0015] Step 3 (S3): Gradient heating and environmental control.

[0016] After the dormancy-breaking treatment cycle is completed, the insulation and shading blankets are removed, and the temperature management phase begins. This phase primarily involves controlling the temperature inside the greenhouse through adjustments to the greenhouse's physical equipment. During the day, natural heating is achieved using solar radiation, maintaining the temperature between 15-28℃. If the temperature exceeds 28℃, the ventilation openings at the top and bottom of the greenhouse are opened to cool the air through convection. At night, the temperature is maintained above 10℃. If the temperature falls below 10℃, insulation and shading blankets are used for insulation, or, if necessary, the heating system is activated for auxiliary heating. The technological innovation of this step lies in fully utilizing the heat storage and insulation properties of the greenhouse, as well as the abundant daytime sunlight resources in cooler regions, to achieve temperature control for peony growth. No artificial supplemental lighting is required throughout the process, further reducing production costs.

[0017] In one specific implementation, the daytime temperature is controlled at 15-25℃ by a ventilation system, and the nighttime temperature is controlled at 5-10℃ by a heat preservation or heating system.

[0018] In one specific implementation, the heating system is an oil-fired hot air furnace, with a configuration standard of ≥15kW heating power per 100m² greenhouse area, and the temperature control system accuracy is ±1℃.

[0019] Step 4 (S4), growth period management.

[0020] From the end of dormancy until just before flowering, apply foliar fertilizer to the plants every 10 days. Use a compound solution of potassium dihydrogen phosphate and boron fertilizer. The purpose of this is to directly supplement phosphorus, potassium, and boron through foliar application, promoting flower bud differentiation, increasing the quantity and quality of flowers, and preventing physiological bud drop caused by micronutrient deficiencies. Later, apply 1.5g / L of zinc glycinate as a foliar spray.

[0021] In one specific embodiment, the potassium dihydrogen phosphate and boron fertilizer compound solution has a potassium dihydrogen phosphate mass concentration of 0.2% and a boron fertilizer mass concentration of 0.1%.

[0022] This invention provides a method for forcing peony cultivation by naturally breaking dormancy at low temperatures. It has the following beneficial effects:

[0023] 1. This invention fully utilizes the naturally low nighttime temperatures in suitable regions during mid-to-late October. By covering the peonies with high-shading cotton quilts during the day to block sunlight and removing the quilts at night for ventilation and cooling, the surface temperature is controlled at ≤7℃, allowing the peonies to naturally accumulate chilling energy in the open field. This eliminates the need for cold storage equipment and artificial low-temperature environments, significantly reducing energy consumption and facility costs, and aligns with green and environmentally friendly principles.

[0024] 2. This invention uses open-field planting instead of potted cultivation, providing ample growing space for the fleshy roots of the peony and avoiding the restriction of root expansion by pots, thus significantly improving the efficiency of root absorption of nutrients and water. Combined with the application of well-rotted organic fertilizer and an irrigation system, soil and environmental humidity are dynamically adjusted to maintain a suitable range, eliminating the problems of localized compaction or nutrient imbalance that may occur with potted substrates, fundamentally enhancing plant vigor.

[0025] 3. Gradual heating simulates natural temperature transition, conforming to the temperature characteristics of each stage of peony growth, avoiding problems such as delayed root development and disordered flowering caused by direct heating, and achieving precise matching of physiological needs and environmental conditions at each growth stage.

[0026] 4. No growth regulators such as gibberellin are used throughout the process. Natural low temperature, combined with temperature and humidity control, induces the buds to synchronously break dormancy, avoiding the inhibition of root development by hormones and the risk of excessive growth of the above-ground parts from the source, which meets the requirements of green production in the modern flower industry.

[0027] 5. This invention simplifies the production management process and enhances the regional adaptability of the technical solution. During the dormancy-breaking period in step two, this technical solution explicitly stops all irrigation and watering operations. In step three, artificial lighting control is also unnecessary. Compared to traditional technologies that require precise multi-parameter coordinated control of temperature, humidity, and light, this invention significantly simplifies the management process, reduces reliance on complex sensing and control systems, and thus lowers operational difficulty and labor costs. More importantly, this method transforms the cold winter climate conditions of Northwest and Northeast my country from a constraint on agricultural production into a usable resource, providing a feasible technical path for low-cost, high-efficiency peony forcing cultivation in these regions, demonstrating clear regional relevance and promotional value. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the method flow of the present invention. Detailed Implementation

[0029] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] Example 1: Cultivation of Peony by Breaking Dormancy Through Natural Low Temperature

[0031] This embodiment provides a specific method for promoting the cultivation of peony by breaking dormancy through natural low temperatures.

[0032] S1. Planting:

[0033] On October 2, 2021, with temperatures ranging from 10 to 20°C, the operation was carried out in a solar greenhouse in Lanzhou, Gansu Province. The greenhouse is equipped with openable and closable heat-insulating and light-blocking quilts, top and bottom ventilation openings, and a basic irrigation system.

[0034] Three-year-old peony seedlings that have passed quarantine and are free from quarantine pests and diseases such as peony root-knot nematodes and gray mold were selected. Each seedling had four plump underground buds without mechanical damage. The seedlings were placed in a 1000-fold diluted solution of carbendazim fungicide and soaked for 15 minutes before being removed and drained.

[0035] Inside the greenhouse, sulfur powder is added to the soil for sterilization and alkalinity reduction. Well-rotted farmyard manure is then applied as base fertilizer and mixed thoroughly with the soil. Planting then proceeds at a spacing of 40cm x 60cm, with ridges 30-40cm high. After planting, all plants are thoroughly watered to ensure complete root contact with the soil. Following this watering, no further watering is permitted until the dormancy-breaking process is complete.

[0036] S2. Natural low-temperature sleep-breaking treatment:

[0037] Since November 10, 2021, monitoring has shown that the local nighttime outside temperature has steadily dropped below 7.5℃, and sleep-breaking treatment has been initiated.

[0038] The specific operation is as follows: At 09:00 daily, cover the greenhouse with a 95% shading blanket; at 17:00 daily, remove the shading blanket and simultaneously open all ventilation openings at the bottom of the greenhouse to allow cold outside air to enter. Real-time monitoring is achieved using temperature sensors installed on the ground surface to ensure the ground temperature is controlled within ≤7.5℃.

[0039] The process lasted 50 days, ending on December 30, 2021. No water replenishment was carried out during this cryogenic treatment.

[0040] S3. Gradient heating and environmental control:

[0041] Starting on December 31, 2021 (after the dormancy break treatment), the temperature rise management phase began.

[0042] Remove the insulating and shading blankets and utilize daytime solar radiation to heat the greenhouse. During the day, maintain the indoor air temperature at 18-22℃ (average 20℃) by opening or closing the ventilation openings at the top of the greenhouse. At night, cover the greenhouse with insulating and shading blankets to maintain the indoor air temperature above 10℃. If the forecast nighttime outside temperature is below -15℃, the indoor temperature may drop below 5℃. In this case, it is necessary to maintain the indoor temperature above 10℃ at night. If the temperature drops below 10℃, cover the greenhouse with insulating blankets or start the fuel-fired hot air furnace with a power configuration of 20kW / 100m² for auxiliary heating. 2 The temperature control accuracy is ±1℃.

[0043] No artificial lighting was used throughout the entire growth process.

[0044] S4. Growth Period Management:

[0045] From the warming stage until the first batch of flower buds show color, apply foliar fertilizer once every 10 days.

[0046] The fertilizer used is a compound solution, prepared as follows: potassium dihydrogen phosphate and boron fertilizer (calculated as pure boron) are dissolved in water to make the final mass concentration of potassium dihydrogen phosphate 0.2% and the final mass concentration of boron fertilizer 0.1%. The solution is then sprayed evenly on both sides of the plant leaves until the leaves are completely wet but not dripping. Later, 1.5 g / L of zinc glycine is sprayed on the leaves.

[0047] Comparative Example 1:

[0048] Compared with Example 1, the difference is that the dormancy breaking process (S2) does not utilize natural low temperature, but is carried out in an artificial cold storage at 0-5°C for 50 days; in the temperature management process (S3), in addition to temperature control, artificial supplemental lighting is provided for 14 hours daily using LED supplemental lights. All other operations are the same as in Example 1.

[0049] Comparative Example 2:

[0050] The difference from Example 1 is that during the S2 natural low-temperature dormancy breaking treatment, the soil was watered once a week to maintain soil moisture at approximately 30%. All other operations were the same as in Example 1.

[0051] Comparative Example 3:

[0052] Compared to Example 1, the difference lies in the cultivation method, which involves pot cultivation. Specifically, standardized production plastic flowerpots with a diameter of 40cm and a depth of 50cm are selected. The cultivation substrate is prepared by mixing garden soil, leaf mold, and perlite in a volume ratio of 5:4:1. Peony seedlings of the same specifications as in Example 1 are planted in these flowerpots. All subsequent steps, including natural low-temperature dormancy breaking, gradient heating and environmental control, and growth period management, are carried out in the same greenhouse as in Example 1, subjecting these potted plants to identical environmental control and management practices.

[0053] Test Example 1: Comparison Test of Cultivation Effect and Production Cost

[0054] 1. Testing Method

[0055] To verify the technical effects of the present invention, a comparative test was conducted on the cultivation effects and production costs of the peonies cultivated in Example 1, Comparative Example 1, and Comparative Example 2.

[0056] 1.1 Production Cost Statistics

[0057] 100m 2 As a unit of measurement, energy consumption for each group was recorded throughout the entire cycle from planting to cut flower harvest. Electricity meters were used to record the electricity consumption of the artificial cold storage and LED supplemental lighting in Comparative Example 1; fuel flow meters were used to record the fuel consumption of the fuel-fired hot air furnaces activated due to extreme low temperatures in Examples 1 and 2. The recorded consumption was converted into total energy costs based on local industrial electricity and diesel prices.

[0058] 1.2 Statistics on agronomic traits and yield and quality

[0059] When the peonies entered their peak flowering period, 50 representative plants of varying growth status were randomly selected from the greenhouses of Example 1, Comparative Example 1, and Comparative Example 2, respectively, and the following indicators were measured and statistically analyzed:

[0060] (1) Root rot rate (%): After the sample plants are dug up completely and the soil around the roots is cleaned, the number of plants with blackened, softened and rotten root tissues is checked and recorded, and the percentage of the total number of samples is calculated.

[0061] (2) Germination rate (%): The germination rate is calculated by dividing the total number of underground buds that successfully sprouted and broke through the soil on 50 sample plants by the total number of underground buds on these 50 plants at the time of planting.

[0062] (3) Flowering rate (%): The percentage of plants in the sample that successfully opened at least one flower was calculated.

[0063] (4) Flowering start date (days): Record the number of days from the end of the dormancy treatment (December 31) to the appearance of the first fully open flower in each sample group.

[0064] (5) Average number of flower stems per plant: The total number of cut flowers that meet the harvestable standards in terms of length and openness on 50 sample plants is counted, and then divided by 50 to calculate the average number of flower stems per plant.

[0065] 2. Test Results

[0066] The above statistical and measurement data are summarized in the table below.

[0067] Table 1: Comparison of the impact of different cultivation methods on peony growth and cost

[0068]

[0069] The test results in Table 1 show that the technical solution adopted in Example 1 has a significant difference in energy cost compared to Comparative Example 1. The mechanism behind this cost difference lies in the fact that the dormancy-breaking step in this technical solution uses the low temperatures of nighttime in nature as a cold source, replacing the artificial refrigeration equipment in Comparative Example 1 that requires continuous power consumption. Simultaneously, during the warming and growth stage, the solution utilizes solar radiation energy through physical control of the solar greenhouse, replacing the artificial supplemental lighting system in Comparative Example 1 that requires a large amount of power consumption. The combination of these two technical features is the direct reason for the significant reduction in total energy cost.

[0070] The comparison between Example 1 and Comparative Example 2 demonstrates the direct impact of soil moisture management during dormancy-breaking treatment on cultivation results. Comparative Example 2, due to supplemental watering during the low-temperature dormancy-breaking period, exhibited an extremely high root rot rate, directly leading to extremely low subsequent budding and flowering rates. The mechanism lies in the fact that peony roots exhibit weak physiological activity and extremely low water requirements during low-temperature dormancy. Excessive soil moisture at this time creates an oxygen-deficient environment for the roots, providing breeding grounds for soil-borne pathogens in a low-temperature, high-humidity environment, ultimately causing widespread root rot and destroying the material and structural basis for plant recovery and growth.

[0071] In summary, this technical solution combines two key techniques—naturally lowering the temperature to break dormancy and ceasing watering during the dormancy period—to achieve dual technical benefits. Firstly, by utilizing natural energy instead of artificial energy, it effectively reduces production costs. Secondly, by creating a dry, low-temperature dormancy environment, it effectively prevents root rot caused by improper water management, ensuring plant survival and subsequent growth. This combination of techniques results in positive outcomes in both economic efficiency and cultivation success rate.

[0072] Test Example 2: Comparative Test of the Effects of the Method of the Present Invention and the Potted Method on the Yield and Economic Benefits of Peony During its Perennial Growth Period

[0073] 1. Testing Method

[0074] To further verify the sustained benefits of the method of the present invention in perennial cultivation, this test was established.

[0075] 1.1 The test subjects were peonies cultivated in Example 1 (open field cultivation in a solar greenhouse) and Comparative Example 3 (potted cultivation in a solar greenhouse).

[0076] 1.2 Testing Period and Data Acquisition The testing period is three consecutive years, with the year of planting being recorded as the first year.

[0077] (1) Annual cut flower production statistics: During the peak flowering season each year, the number of cut flowers (flower stems) produced by a single plant that meet the commercial standards in Example 1 and Comparative Example 3 were recorded and statistically analyzed.

[0078] (2) Final root yield determination: After the third cut flower harvest season, the sample plants in Example 1 and Comparative Example 3 were completely dug up (or removed from the pot), the soil around the roots was washed, and the fresh weight of the entire underground root system was measured.

[0079] (3) Input-output ratio calculation: The total input costs (including seedlings, substrate, fertilizer, water, electricity, fuel, and labor, etc.) and total output value of the two groups over the three-year period are calculated separately. The total output value is calculated based on the total number of cut flowers accumulated over the three years and the market price of the finally harvested roots (calculated as medicinal materials). The final result is presented in the form of "input cost: output value".

[0080] 2. Test Results

[0081] The observation and measurement data from the past three years are summarized in the table below.

[0082] Table 2: Effects of open-field cultivation and potted cultivation on the yield and economic benefits of peony during its perennial growth period

[0083]

[0084] Table 2 clearly shows that cultivation methods have a fundamental impact on the yield and economic benefits of peonies over their multi-year growth cycle. The open-field cultivation method used in Example 1 showed a steady increase in cut flower yield year by year; while the potted cultivation method in Comparative Example 3 showed a significant decrease in cut flower yield year by year after a brief period of stagnation. The mechanism of this phenomenon is that open-field cultivation provides unrestricted growth space for the fleshy roots of peonies, allowing the roots to expand year by year, accumulate more nutrients, and thus support the more robust growth of the above-ground parts of the plant and the differentiation of more flower buds. Conversely, the limited volume of flowerpots severely restricts root extension, leading to root tangling, hindered growth, and a decline in the overall vitality of the plant from the second year onwards, directly reflected in the year-by-year decrease in cut flower yield.

[0085] A more significant difference lies in the final yield of the underground parts. The average fresh weight of the root system per plant in Example 1 is nearly three times that of Example 3. This directly demonstrates that open-field cultivation can promote the biomass accumulation of peony rhizomes, which are important medicinal parts and propagation materials. The huge difference in input-output ratio is a direct economic manifestation of the aforementioned yield difference. Example 1, through a single planting, not only achieved continuously increasing cut flower revenue but also obtained a high-value-added underground root system yield at the end of the cultivation cycle, thus exhibiting extremely high economic benefits. In contrast, the potted method, due to limited yield, has a much lower long-term economic return than the method used in this invention.

[0086] Test Example 3: Comparative Test of the Effects of the Invention Method and the Potted Plant Method on the Quality of Cut Peony Flowers

[0087] 1. Testing Method

[0088] To objectively evaluate the impact of the method of the present invention on the final quality of cut flowers, peonies cultivated in Example 1 (open field cultivation in a solar greenhouse) and Comparative Example 3 (potted cultivation in a solar greenhouse) were used as test subjects to conduct comparative tests on key quality indicators of cut flowers.

[0089] 1.1 Quality Indicator Measurement

[0090] During the peak flowering period of the third year, 50 plants were randomly selected from the greenhouses of Example 1 and Comparative Example 3, and the best-growing flower stalk from each plant was selected as a sample, for a total of 50 sample flower stalks. The following indicators were measured:

[0091] (1) Plant height (cm): The vertical height of the sample plant from the ground surface (or the surface of the potting soil) to the top of the corolla.

[0092] (2) Stem diameter (mm): Use vernier calipers to measure the diameter of the flower stem 10cm above the base of the sample.

[0093] (3) Flower diameter (cm): The maximum straight-line distance between the edges of the corolla when the sample flower is fully open.

[0094] 1.2 Quality Test of Bottle-Ending Period

[0095] On the same day, 30 cut flowers of the same commercial maturity (half-open buds, just beginning to show color) were randomly collected from each of the two groups. The bases of all cut flowers were trimmed to the same length (50 cm) and immediately placed into clean glass bottles containing equal volumes of distilled water, 10 flowers per bottle. All bottles were placed in a standard indoor environment with a temperature of 20℃±1℃, relative humidity of 60%±5%, and 12 hours of diffused light daily. Observations were recorded daily, with the endpoint of vase life defined as the appearance of obvious wilting, dehydration, or neck bending of the petals. The average number of days from insertion into the water bottle to the end of vase life was recorded.

[0096] 2. Test Results

[0097] The measurement and statistical data of the above quality indicators are summarized in the table below.

[0098] Table 3: Effects of open-field cultivation and potted cultivation on the main quality indicators of peony cut flowers

[0099]

[0100] The test data in Table 3 show that the cut flowers produced by the technical solution adopted in Example 1 are superior to those produced by the potted plant method in Comparative Example 3 in all key quality indicators. The mechanism behind this quality difference stems from the fundamental difference in the growth environment provided to the plant roots by the two cultivation methods. The open-field cultivation method in Example 1 removes the physical container's restriction on root extension, allowing the peony's fleshy roots to grow freely and deeply in the soil. A larger and more developed root system has a much higher total surface area and efficiency for absorbing water and mineral nutrients than the restricted root system in a pot. This advantage in nutrient absorption provides a solid material basis for the robust development of the plant's above-ground parts, directly manifested in greater plant height, thicker flower stems, and larger flowers.

[0101] The significant extension of the vase life is a direct reflection of the overall health of the plant. In Example 1, due to the strong root absorption function, the above-ground parts of the plant grow more vigorously, and the vascular bundle structure inside the flower stem is more developed and intact. This means that after the flower stem is harvested as a cut flower, its ability to absorb and conduct water from the vase solution is stronger, and it can maintain cell turgor pressure and tissue physiological activity for a longer period of time, thereby effectively delaying the wilting and decay of the petals and achieving a longer vase life. Therefore, this technical solution achieves a full-chain improvement from basic plant development to final commercial quality by optimizing the root growth environment.

[0102] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for cultivating Paeonia lactiflora Pall. by using natural low temperature to break the dormancy, which is suitable for cultivation in cold and cool regions in the northwest and northeast of China, characterized in that, Comprise the following steps: S1. Sunlight greenhouse ground planting: in early October every year when the temperature is 10-20℃, the ground cultivation of peony is carried out in a sunlight greenhouse with heat preservation shading cotton, ventilation system and irrigation system, realizing one planting and multi-year harvesting; the peony seedlings are planted in a ridge with a plant row spacing of 50cm*50cm, the ridge height is 30-40cm, the peony seedlings are sterilized before planting, sulfur powder is added to the soil for sterilization and alkali reduction, and mature organic fertilizer is applied as base fertilizer; once water is poured after planting, and soil humidity is strictly controlled during subsequent growth to avoid root rot caused by excessive humidity; S2. Natural low temperature breaking dormancy treatment: when the night temperature can be stably reduced to below 7.5℃, breaking dormancy treatment can be started, shading cotton is covered for shading from 09:00 to 17:00 every day, and the shading cotton is removed from 17:00 to 09:00 the next day and the bottom ventilation port of the greenhouse is opened, the peony is broken dormancy by using natural low temperature at night, the ground temperature is monitored in real time to ensure that the ground temperature is controlled at ≤7.5℃, the process lasts for 45-70 days, and no water supplement is performed during the whole breaking dormancy period; S3. Gradient temperature rise and environmental regulation: after the dormancy breaking is completed, the shading cotton is removed, natural temperature rise is carried out by using daytime light, the temperature in the greenhouse is regulated by opening and closing the ventilation ports at the top and bottom of the greenhouse and the shading cotton, the daytime temperature is maintained at 15-28℃, and if the temperature is higher than 28℃, the ventilation port is opened to reduce the temperature; the temperature in the greenhouse at night is maintained above 10℃, and if the temperature is lower than 10℃, the shading cotton is covered or the heating system is started to heat, and when the application is in a suitable area, no artificial light supplement is needed; S4. Growth period management: after the dormancy breaking is completed, the peony is sprayed with a potassium dihydrogen phosphate and boron fertilizer compound solution every 10 days before flowering, and the peony is sprayed with zinc glycinate 1.5g / L in the later period.

2. The method for cultivating by using natural low temperature to break the sleep of Paeonia lactiflora Pall. according to claim 1, characterized in that, The peony seedlings in S1 need to meet the following conditions: 3-4 years old, each plant has 3-5 healthy underground buds, the buds are full and have no mechanical damage; no peony root knot nematode and botrytis cinerea quarantine pests and diseases.

3. The method for cultivating by using natural low temperature to break the sleep of Paeonia lactiflora Pall. according to claim 1, characterized in that, The sterilization treatment in S1 refers to soaking the peony seedlings in a 800-1000 times water diluted carbendazim fungicide solution for 10-20 minutes.

4. The method for cultivating by using natural low temperature to break the sleep of Paeonia lactiflora Pall. according to claim 1, characterized in that, The shading rate of the shading cotton covered in S2 is ≥90%.

5. The method for cultivating by using natural low temperature breaking-sleeping paeonia to promote growth according to claim 1, characterized in that, The heating in S3 means that the heating power is configured as 15 kW per 100 m 2 of greenhouse area by fuel hot air furnace, and the temperature control accuracy is ±1℃.

6. The method for cultivating by using natural low temperature breaking-sleeping paeonia to promote growth according to claim 1, characterized in that, In S3, the temperature in the greenhouse is controlled to be 15-28℃ during the day by the ventilation system, and the temperature in the greenhouse is controlled to be higher than 10℃ at night by the heat preservation or heating system.

7. The method for cultivating by using natural low temperature breaking-sleeping paeonia to promote growth according to claim 1, characterized in that, The potassium dihydrogen phosphate and boron fertilizer compound solution in S4 refers to a solution with a potassium dihydrogen phosphate concentration of 0.2% and a boron fertilizer concentration of 0.1%.

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