Lifting type high-density strawberry annual production method capable of breeding seedlings in spring and summer and fruiting in autumn and winter

Abstract

The invention relates to the field of plant cultivation, and particularly discloses a lifting type high-density strawberry annual production method capable of breeding seedlings in spring and summer and fruiting in autumn and winter, which comprises the following steps: planting strawberry stock plants on a lifting type high rack after cold demand accumulation, and carrying out long-day high-temperature treatment to promote stolons to grow; cutting the seedlings formed on the stolons into a hole tray placed on a high rack in a pressure drawing manner, cultivating until the root system is robust, and cutting off the stolons; the obtained child seedlings are new seedlings, and the mother plants are old seedlings; and processing the new seedlings and the old seedlings at low temperature and short day in autumn and winter so as to enable the new seedlings and the old seedlings to bud and bear fruits in autumn and winter of the current year, and harvesting the strawberries mature in the next year. According to the method, strawberry stock plants are subjected to low-temperature refrigeration treatment before field planting, it is ensured that stolons are bred in spring and summer, plug seedlings needed by production are cultivated, meanwhile, the stock plants are kept to continue to bear fruits, tillering increase, inflorescence increase and fruit increase are promoted due to the fact that a large number of stolons grow, and the high-yield effect is achieved.

Description

Technical Field

[0001] The present invention belongs to the field of plant cultivation, and particularly relates to a method for annual production of strawberries with elevated and high-density seedling propagation in spring and summer and fruit bearing in autumn and winter. Background Art

[0002] Strawberry ( Fragaria ananassa Duch.), Rosaceae, is a perennial herb. It has a delicious taste and rich nutritional value, and is known as the "queen of fruits". The rise of the strawberry industry has brought huge social and economic benefits. The production scale of strawberries has been gradually expanding, and the demand for strawberry seedlings has also increased significantly.

[0003] The main season for strawberry seedling propagation is from spring to late summer and early autumn. The shorter the sunshine and the lower the temperature in late summer and early autumn, the more beneficial it is for the flower bud differentiation of seedlings and the fewer the pests and diseases.

[0004] In view of problems such as the low height of strawberry plants and the inappropriateness of ground planting for sightseeing and picking, as well as the difficulties that workers need to bend down for a long time during ground planting operation and management, which is easy to cause fatigue, and the high death rate of daughter seedlings after planting in open-field soil, the method of rain-sheltered seedling raising using facilities has been gradually promoted and applied in production. The emergence of elevated seedling raising has solved many problems. Compared with conventional seedling raising, elevated and liftable seedling raising shows significant advantages in improving the seedling propagation rate, the quality of daughter seedlings, the transplanting survival rate, and reducing pests and diseases. Elevated seedling propagation is the best method to ensure the quality of strawberry daughter seedlings and the seedling propagation method compared with other seedling raising methods.

[0005] Usually, solar greenhouses are used for single production of fresh strawberry fruits or solely for the propagation of stolons. The two are separated from each other, and new seedlings need to be planted. The former is mainly planted in September and ends in April or May, while the latter plants new mother plants in March for the propagation of stolon seedlings and ends in August. This causes waste of space and plant materials.

[0006] In elevated seedling propagation, how to ensure the normal flowering and fruiting of two-year-old mother plants while meeting the increasing demand for strawberry seedlings, realizing that the same strawberry mother plant first propagates stolon seedlings and then flowers and fruits, and ensuring that the quantity and quality of strawberry stolons, the fruit yield and quality during the high-price period throughout the year (from December to February of the next year) are not affected, are the technical problems to be solved by the present invention. Summary of the Invention

[0007] In view of the above problems, the present invention provides a method for annual production of strawberries with elevated and high-density seedling propagation in spring and summer and fruit bearing in autumn and winter.

[0008] The present invention provides a method for annual production of strawberries with high-density spring and summer seedling propagation and autumn and winter fruiting by means of lifting, which includes the steps of planting strawberry mother plants on a lifting high rack after the accumulation of chilling requirement, promoting the occurrence of stolons by long-day high-temperature treatment, guiding and pressing the daughter plants formed on the stolons for cutting and inserting into the plug trays placed on the high rack for cultivation until the root systems are strong and then cutting off the stolons; the obtained daughter plants are new plants, and the mother plants are old plants; treating the new plants and the old plants with low temperature and short-day in autumn and winter to make them both flower and fruit in the current autumn and winter, and mature and be harvested in the strawberry fruit growth season of the next year.

[0009] In the above method, the accumulation of chilling requirement is treatment at 5 °C for more than two months.

[0010] In the above method, the long-day high-temperature treatment is 16 hours of sunshine per day, with the daytime temperature controlled at 28 - 30 °C and the nighttime temperature at 18 - 20 °C.

[0011] In the above method, the time for guiding and pressing is from May to late June.

[0012] In the above method, for each mother plant, 10 - 15 daughter plants are formed by guiding and pressing.

[0013] In the above method, for the cultivation until the root systems are strong, the cultivation conditions are 8 hours (inclusive) or more of light per day, with the daytime temperature controlled at 28 - 30 °C and the nighttime temperature at 18 - 20 °C, and watering once every 2 - 3 days.

[0014] In the above method, the stolons are cut off 2 - 3 weeks after guiding and pressing.

[0015] In the above method, for the low-temperature short-day treatment, the daytime temperature is 20 °C - 30 °C, and the nighttime temperature is not lower than 10 °C.

[0016] In the above method, the strawberry varieties are selected from Hongyan, Sweet Charlie, and Xiangye.

[0017] The method for annual production of strawberries with high-density spring and summer seedling propagation and autumn and winter fruiting by means of lifting according to the present invention specifically includes the following steps: S1. Plant the strawberry mother plants after the accumulation of chilling requirement on a lifting high rack; S2. Conduct long-day high-temperature treatment on the strawberry mother plants to promote the occurrence of stolons, guide and press the daughter plants formed on the stolons for cutting and inserting into the plug trays placed on the high rack, cultivate for 2 - 3 weeks after guiding and pressing until the growth is strong, with 2 or more expanded leaves and 3 or more white adventitious roots exposed, and cut off the stolons. The daughter plants are the newly propagated plants, and the mother plants are the old plants; The long-day high-temperature treatment is 16 hours of sunshine per day, with the daytime temperature controlled at 28 - 30 °C and the nighttime temperature at 18 - 20 °C; The post-inoculation cultivation is carried out under the following conditions: the light exposure is 8 hours or more per day, the daytime temperature is controlled at 28-30°C, the nighttime temperature is 18-20°C, and watering is done once every 2-3 days. S3. From September to October of the current year, low-temperature and short-day treatment is carried out, with the daytime temperature controlled at 20°C - 30°C, the nighttime temperature at 5-10°C, and the light exposure time at 8h to promote flower bud differentiation. Both the new seedlings and the old seedlings will bloom from October to November and the fruits will be harvested from December to February of the following year.

[0018] In the above method, for the new seedlings, excessive watering should be avoided during the initial growth stage, and the temperature should be controlled at 20-25°C.

[0019] In the above method, the method also includes water and fertilizer management and pest and disease control.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows: In the present invention, in the solar greenhouse in March, the strawberry seedlings after the accumulation of chilling requirements are planted on the elevated rack. Through field management methods such as water and fertilizer management, light, temperature and humidity control, stolons are normally propagated during spring and summer to provide strawberry daughter seedlings for the new year, reducing the shortage of plug seedlings for elevated cultivation. The quality of the daughter seedlings is controllable and does not affect the elevated cultivation of the new year. In the same year, the mother plants are retained and normally cultivated to ensure water and fertilizer supply. Because a large number of stolons are drawn, the strawberry can increase tillering. Retain 3-5 lateral buds, trim the plants, remove the old leaves with the included angle between the petiole and the ground less than 15°, and mound the rhizome without covering the apical buds of the tillers. During the growth period of the mother plants in the second year, compared with the new seedlings, the growth process is reduced and the tillering increases, promoting more inflorescences and increasing the strawberry fruit yield, with the yield increasing compared to the new seedlings. The strawberry seedlings can bear fruit normally after seedling propagation. Description of the Drawings

[0021] Figure 1 This is a photo of the strawberry seedling planting and lifting system used in Example 1 of the present invention for planting.

[0022] Figure 2 This is a photo of the stolons when the strawberry seedling planting and lifting system used in Example 1 of the present invention is used for planting.

[0023] Figure 3 This is a photo of the water and fertilizer machine screen when the strawberry seedling planting and lifting system used in Example 1 of the present invention is used for planting.

[0024] Figure 4 This is a photo of the new Sweet Charlie seedlings in Example 1 of the present invention.

[0025] Figure 5 This is a photo of the old Sweet Charlie seedlings in Example 1 of the present invention.

[0026] Figure 6 This is a photo of strawberry aphids.

[0027] Figure 7 It is a photo of strawberry powdery mildew.

[0028] Figure 8 It is the statistical result of the single fruit weight of new strawberry seedlings, old seedlings with soil covering, and old seedlings without soil covering in Example 1 of the present invention.

[0029] Figure 9 It is the statistical result of the soluble solid content of new strawberry seedlings, old seedlings with soil covering, and old seedlings without soil covering in Example 1 of the present invention.

[0030] Figure 10 It is the statistical result of the single plant yield of old strawberry seedlings with soil covering and old seedlings without soil covering from December to February in Example 1 of the present invention.

[0031] Figure 11 It is the statistical result of the average single plant yield of new strawberry seedlings, old seedlings with soil covering, and old seedlings without soil covering from December to February in Example 1 of the present invention. Detailed implementation manners

[0032] The present invention will be further described in detail below in combination with the detailed implementation manners. The given examples are only for clarifying the present invention, rather than limiting the scope of the present invention. The following provided examples can be used as a guide for those of ordinary skill in the art to make further improvements, and do not limit the present invention in any way.

[0033] The experimental methods in the following examples are all conventional methods unless otherwise specified, and are carried out according to the techniques or conditions described in the literature in this field or according to the product specifications. The materials, reagents, etc. used in the following examples can be obtained from commercial channels unless otherwise specified.

[0034] Preliminary test The preliminary test in the early stage started in December of the previous year. The strawberry mother plants were placed in a 5°C cold storage for 2 months for cold requirement accumulation and then planted. It was compared with the situation without cold requirement accumulation (normal temperature) before planting. The number of stolons per plant was counted during the stolon emergence stage from May to June of the current year. The results are shown in Table 1. Cold requirement accumulation before planting significantly promoted the emergence of stolons, laying a solid foundation for breeding more and stronger daughter seedlings in the follow-up.

[0035] Table 1

[0036] Example 1 From 2023 to 2024, this example was carried out in the greenhouse of the Institute of Forestry and Pomology, Beijing Academy of Agriculture and Forestry Sciences.

[0037] In this embodiment, a single-story arched steel-frame greenhouse is adopted, facing north-south. Ventilation openings are provided on the plastic films on both the east and west sides of the greenhouse. The upper edge of the upper ventilation opening is 1.5 m away from the arch top, and the lower edge of the lower ventilation opening is 0.3 m away from the ground. Insect-proof nets with 40 meshes need to be installed at the ventilation openings. An automatic switch skylight is set above the greenhouse roof to achieve ventilation and temperature adjustment in spring, summer, and autumn. An electric sunshade net is installed on the top of the greenhouse body.

[0038] The seedling-raising rack can adopt the strawberry seedling planting lifting system. The strawberry seedling planting lifting system used in the present invention is the strawberry seedling planting lifting system with the product model of HDST-SJZPC-60L produced by Shandong Hongding Ecological Development Co., Ltd. For details, see Figure 1 . The strawberry seedling planting lifting system includes a lifting drive assembly, a towing rope connected to the lifting drive assembly, and a hanging hook member provided at the bottom end of the towing rope. The strawberry seedling cultivation trough (a foam box) is connected to the hanging hook member. By winding the towing rope through the lifting drive assembly, the strawberry seedling cultivation trough is driven to lift and lower.

[0039] In view of problems such as the low height of strawberry plants and the inappropriateness of ground planting for sightseeing and picking, as well as difficulties such as the need for ground-planting workers to bend down for a long time during operation and management, which is prone to fatigue, the applicant adjusts the height of the seedling-raising platform according to the length of stolons, establishes a suspended lifting trough-type three-dimensional cultivation system, and freely regulates the lifting and lowering of the cultivation trough through mechanical transmission, with a higher planting space density and higher yield.

[0040] The strawberry seedling varieties used in this embodiment are Hongyan, Sweet Charlie, Xiangye, and Monterey, all of which are commercial strawberry varieties and can be purchased in the market by the public.

[0041] The plug trays used in this embodiment are 32-hole plug trays (4×8) and 21-hole plug trays (3×7) made of ordinary plastic materials.

[0042] Substrate: The Yangyangle seedling-raising substrate produced in Shancheng Town, Meihekou City, Jilin Province is adopted. It is a mixed substrate composed of peat, vermiculite, perlite, and coconut coir, with a pH value of 5.5 - 6.5 and an EC value of less than 0.5 ms / cm.

[0043] 1. Lifting-type high-density spring and summer seedling propagation and autumn and winter fruiting strawberry annual production method and its seedling-raising effect Start the production of spring and summer seedling propagation and autumn and winter fruiting strawberries in the first year on the elevated rack, including the following steps: S1. After the strawberry mother plants accumulate the chilling requirement from December of the previous year to February of the current year, they are planted on the lifting-type elevated rack in March of the current year. Specifically as follows: Select high-quality mother plants of four varieties, namely Hongyan, Sweet Charlie, Xiangye, and Monterey, and store them in a 5°C cold storage from December 2022 to February 2023 for chilling requirement accumulation.

[0044] In March 2023, it was planted on both sides of the cultivation trough on the elevated rack, with a plant spacing of 20 cm. Each variety was planted in one row of the cultivation trough. Ensure thorough watering 3 days after planting, and avoid excessive moisture subsequently. After survival, the mother plants need to be managed in the field multiple times to reduce nutrient competition from weeds, increase soil aeration, and keep the soil loose. Maintain normal water and fertilizer management. The humidity in the greenhouse should be reduced in a timely manner. Open the air vents every morning to reduce humidity and prevent the occurrence of diseases. During the entire subsequent strawberry growth cycle, ensure normal light, patrol the greenhouse every day to remove weeds, and monitor the growth and disease conditions of strawberry seedlings; pay attention to sudden drops in temperature at night.

[0045] S2. After planting, perform long-day high-temperature treatment on strawberries to promote the occurrence of stolons; The occurrence of stolons requires long-day and high-temperature environmental treatments to ensure the cultivation quantity of daughter plants, so as to guarantee the strawberry fruit production in the next year (from autumn 2023 to spring 2024). After the strawberry mother plants are planted in March, long-day high-temperature treatment begins. The stolon propagation of mother plants is carried out from May to late June 2023.

[0046] After planting in March 2023, start long-day high-temperature treatment (16 hours of sunshine per day, daytime temperature controlled at 28 - 30 °C, and 18 - 20 °C at night) to promote the occurrence of stolons. Stolons can occur with long sunshine hours, and within a certain range, the amount of stolons increases with the increase in temperature. When entering the stage of massive stolon growth, pay attention to combing the stolons to ensure that each stolon hangs naturally, which is convenient for later guiding and pressing the daughter plants. Along with the increase in sunshine and temperature, shade and cool the seedling-raising greenhouse in a timely manner. Open the shading net at noon in time. When the temperature in the greenhouse is high, carry out external shading and take cooling measures such as opening air vents, fans, and wet curtains. After the stolons start to occur, avoid damaging the stolons during intertillage and weeding. During the period of stolon breeding, removing flower buds is essential during the seedling-raising period, and the earlier it is removed, the better, to reduce nutrient consumption.

[0047] When the stolon daughter plants meet the seedling-raising requirements (from May to late June), about 25 daughter plants can be formed on each mother plant. During the breeding process, the weaker stolons can be removed in a timely manner, and 10 - 15 strong daughter plants are left on each plant. Start the cutting treatment by guiding and pressing the stolons. The daughter plants are cut and planted into plug trays (32-hole plug trays) placed on the elevated rack for daughter plant cultivation. The cutting treatment adopts the elevated seedling-raising method. Fill the 32-hole plug trays with the prepared seedling-growing substrate, ensure thorough watering, and place the plug trays flat on the elevated rack so as not to affect the mother plants and ensure that the stolons grow in a relaxed state. Use a strawberry seedling fork to fix the root of each daughter plant at the center of the hole. Try to ensure that the large seedlings are cut and planted close to the mother plant, and the small seedlings are cut and planted far from the mother plant, which is convenient for subsequent grading of daughter plants. During the cutting process, do not break the stolons. Water immediately after cutting the seedlings and do a good job in shading treatment.

[0048] During the cultivation of daughter plants, the daily light in the greenhouse should be controlled for 8 hours (inclusive) or more. The daytime temperature should be controlled at 25-30 °C, and the nighttime temperature at 15-20 °C. Water should be applied twice a day, morning and evening, two days before cutting, to ensure the humidity is above 70%. After planting, water should be applied twice a day, morning and evening, for 3 days, and then once every 2-3 days (spray watering is used), and it is not advisable to have excessive moisture later. Roots can grow in about a week, and the daughter plants can be lifted to check if the roots have formed lumps with the substrate. After 2-3 weeks of guiding and pressing, the roots of the daughter plants grow strong, with more than 2 unfolded leaves and more than 3 white adventitious roots showing. The stolons can be separated from the mother plant. Cut the stolons from the mother plant. The daughter plants should retain slightly longer stolons to facilitate distinguishing the planting direction of the planted strawberries in subsequent seedling cultivation. In the initial growth stage of the daughter plants, it is not advisable to water too much. At this point, the daughter plants are the newly propagated seedlings, and the mother plants are the old seedlings.

[0049] After 2-3 weeks, the new daughter plants (by this time, the roots and the substrate in the plug tray have formed lumps) are pulled out together with the substrate and transferred to 21-hole plug trays respectively to avoid affecting root respiration. Note that watering should be stopped 1 day before grading the daughter plants to prevent the substrate from loosening during the process of lifting the seedlings. If the daughter plants have yellow, diseased, or old leaves, they can be removed casually during the grading process, and 3-4 healthy leaves should be retained. About 40 days after guiding and pressing, the daughter plants can be timely planted on the elevated rack. At this time, the leaves of the daughter plants are strong and the roots are developed, and the survival rate after planting is high.

[0050] Check the survival situation in a timely manner after planting: Remove the dead seedlings and the surrounding substrate at the same time and take them out of the planting area for burial. Randomly select daughter plants to check for disease conditions one week after planting. Inspect the greenhouse on time every day to master the growth of the seedlings and the occurrence of pests and diseases. At the end of the three-week seedling recovery period, use drip irrigation tape to water regularly with fertilizer and water, twice a day, morning and evening, which is most suitable. The fertilizer and water are controlled by a fertilizer and water machine (see the screen photo in Figure 3 ) The fertilizer and water used are filled in buckets A, B, and the acid bucket. Bucket A contains trace elements manganese, copper, zinc, boron, molybdenum, ammonium dihydrogen phosphate, potassium nitrate, potassium sulfate, and magnesium sulfate; Bucket B contains calcium nitrate, potassium nitrate, and Fe-13; the acid bucket is used to adjust the pH. During the growth and development period of strawberries, the EC is controlled at about 1, and the pH is controlled at 5.5-6.5.

[0051] After the plug tray seedlings are transplanted into the greenhouse, they grow fast in the early stage, have a fast seedling recovery speed, a high survival rate, and fewer supplementary seedlings, saving a lot of labor costs. The flowering and fruiting periods of the plug tray seedlings are early, and the strawberry fruits can be put on the market earlier, which is conducive to obtaining higher economic benefits, thus achieving the goals of high yield and stable yield.

[0052] During the growth period of old strawberry plants, field management and flower and fruit management are the two main parts, ensuring the healthy growth of strawberry plants. In the cultivation of old strawberry plants in the new year, on the basis of unified drip irrigation and fertilizer and water treatment, one month after the new seedlings are planted, the treatment of nourishing the roots of old strawberry plants with fertilizer and water is started: amino acid balanced water-soluble fertilizer: N: P2O5: K2O = 15: 15: 15, amino acid ≥ 10%, with a concentration of three to five per thousand, applied once every 7 - 10 days.

[0053] The pest and disease management of old strawberry plants is also particularly important. In the prevention and control of spider mite pests, which will affect the growth of strawberry leaves, it should be prevented in advance. Predatory mites are released in the greenhouse for biological control. Since most of them parasitize on the back of old strawberry leaves, leaves, weeds and withered plants should be removed in time during the seedling cultivation period to cut off the spread of spider mite eggs at the source. The growth conditions of Botrytis cinerea are special. Its growth temperature is roughly the same as that during the strawberry fruiting period, both around 25 °C, but the humidity needs to be above 90%. It is necessary to check the temperature and humidity of the greenhouse regularly at fixed points. Ventilate in time every morning to adjust the humidity in the greenhouse.

[0054] Aphids (see Figure 6 ) mostly appear in high-temperature and dry environments, are harmful to the leaves and petioles of strawberries, and can also spread strawberry viruses. Aphids suck the sap on the strawberry stems, affecting the growth and development of strawberries, and their reproduction is extremely fast and difficult to control. Imidacloprid can be used for prevention and control, with alternative use of pesticides.

[0055] At the same time, agricultural control measures are adopted, such as timely removing weeds and damaged plants around the greenhouse, installing insect-proof nets, adding yellow sticky traps on strawberry plants, and replacing them regularly.

[0056] During the period of planting daughter seedlings, the soil covering treatment of old strawberry plants is carried out synchronously. Select a row in the same cultivation trough and divide it into four areas for soil covering experiments (due to one-year growth, the strawberry roots are gradually exposed to the air and need to be covered with substrate). Treatments are carried out at intervals, and the differences in single fruit weight, sugar content and yield between soil-covered and non-soil-covered are compared during the harvest period.

[0057] Observe the new seedlings during the flower bud differentiation period. After the flower bud differentiation is completed, the grown daughter seedlings are planted in the cultivation troughs on the elevated racks in September - October, and are normally cultivated to make them flower and bear fruit.

[0058] At present, the research on the matrix cutting technology of strawberry stolons mostly focuses on the production seedling propagation stage. The cultivation of seedlings by stolon cutting is mainly carried out by farmers according to experience, and there is a lack of standardized technology in matrix cutting. The present invention realizes early root promotion, timely humidity control, reasonable water and fertilizer management and pest and disease prevention and control (for strawberry powdery mildew, see Figure 7)Combined with other means such as (), the survival rate of stolon cuttings for seedling cultivation has reached over 95%. At the same time, the mother plants that produce stolons are retained. After fertilizer and water treatment and temperature and humidity management, without using the conventional method of removing old seedlings in the past, the old seedlings are further cultivated to flower and bear fruit.

[0059] S3. Low-temperature and short-day treatment promotes the budding and fruiting of daughter seedlings and mother plants in the autumn and winter of the same year (referring to September to October 2023), and the fruits will mature and be harvested in the strawberry fruit growth season of the following year (referring to mid-December 2023 to February 2024).

[0060] During the budding and fruiting period in autumn and winter, due to the continuous and overlapping characteristics of strawberry flowering and fruiting in the greenhouse, the temperature in the greenhouse during the day after budding should be controlled at 20℃ - 30℃, and the temperature at night should be 5 - 10℃. The maximum temperature in the greenhouse at noon should not exceed 30℃, otherwise it will affect the flowering and fruiting of strawberries. The lighting time is 8 hours to promote flower bud differentiation.

[0061] As a result, the tillering number of old strawberry seedlings increases, the inflorescence formation increases, the yield increases, and the fruit quality is not affected. The new strawberry seedlings also all bear fruit smoothly, without affecting the yield in the strawberry fruit growth season of the following year.

[0062] 2. Production effect of the annual production method of high-density spring and summer seedling propagation and autumn and winter fruiting strawberries with a lifting type Using the seedlings cultivated by stolon cuttings of the four varieties obtained by the method of the present invention above as new seedlings (see the photo of the new seedlings of Sweet Charlie in Figure 4 ), and using the mother plants after removing stolons by the method of the present invention above as old seedlings (see the photo of the old seedlings of Sweet Charlie in Figure 5 ), the production effect of the method of the present invention is detected.

[0063] Plant the new seedlings in the elevated cultivation trough, plant the strawberry seedlings on both sides of the cultivation trough, and the plant spacing is 20 cm. According to the length of the cultivation trough, 60 plants of each variety of daughter seedlings are planted.

[0064] During the one-year growth period of old seedlings, the surrounding substrate sinks, and the strawberry roots will gradually be exposed above the substrate. Divide the elevated cultivation trough into four equal-length areas, divide it into four sections on average, and carry out soil cultivation (cultivate soil with a mixed substrate composed of peat, vermiculite, perlite, and coconut coir around the roots) and non-soil cultivation at intervals of two sections. At the beginning of the strawberry growth season, the roots can be covered by the substrate without exposing the roots. There are 10 - 15 old seedlings with soil cultivation and 10 - 15 old seedlings without soil cultivation.

[0065] From December 2023 to February 2024, fruits are harvested successively. Count the fruits harvested in the same batch in December 2023 and February, count the single fruit weight, soluble solids of the fruits, and the yield, and summarize the total yield from December 2023 to February 2024 as the average single plant yield.

[0066] The statistical results of single fruit weight (g) are shown in Figure 8 : The single fruit weight of new Hongyan seedlings is higher than that of old seedlings; while for Sweet Charlie, Xiangye, and Monterey, the single fruit weight of new seedlings is lower than that of old seedlings. There is no significant difference in the single fruit weight between old seedlings with soil covering and old seedlings without soil covering.

[0067] The statistical results of the soluble solid content of fruits are shown in Figure 9 : For Hongyan, Xiangye, and Monterey, the soluble solid content of fruits from old seedlings without soil covering is significantly higher than that of old seedlings with soil covering. For Sweet Charlie, the difference in the soluble solid content of fruits between the two treatments of old seedlings is not significant. The soluble solid content of fruits from new seedlings is lower than that of old seedlings with soil covering and higher than that of old seedlings without soil covering.

[0068] The statistical results of the total yield (kg) of old seedlings from December 2023 to February 2024 are shown in Figure 10 : For Hongyan, Xiangye, and Sweet Charlie, the yield of old seedlings with soil covering is higher than that of old seedlings without soil covering. Monterey starts fruiting at the beginning of March due to variety differences.

[0069] The statistical results of the average yield per plant (kg) from December 2023 to February 2024 are shown in Figure 11 : The average yield per plant of new seedlings of Hongyan, Xiangye, and Sweet Charlie is lower than that of old seedlings with soil covering; the yield of new Hongyan seedlings is equal to that of old seedlings with soil covering. The yield of old seedlings with soil covering is higher than that of old seedlings without soil covering.

[0070] The comparison results of the soluble solid content, single fruit weight, and yield of fruits during the growth season of four strawberry varieties are as follows: The yield of new seedlings is lower than that of old seedlings with soil covering and higher than that of old seedlings without soil covering; the yield of old seedlings with soil covering has mostly increased compared to that of old seedlings without soil covering. The number of flower buds tillering of old seedlings with soil covering is more than that of new seedlings, and the yield in the initial stage is higher than that of new seedlings. The single fruit weight of old Hongyan seedlings is lower than that of new seedlings, while the single fruit weight of old seedlings of other varieties with soil covering is higher than that of new seedlings. In terms of the soluble solid content of fruits, there is little difference between old seedlings and new seedlings, and soil covering is more conducive to the accumulation of soluble solids. Due to variety differences, Monterey bears fruit relatively late, which does not meet the comparison of fruits at the same time and blooms and bears fruit later than new seedlings.

[0071] The new stolon mother plants are planted in March, cultivated normally, and the growth of stolons is terminated in July. During this period, the number of stolons is counted and compared with that of plants normally planted in September. After the strawberry growth season, the number of stolons is counted. The number of stolons per plant of plants planted in March is higher than that of plants normally planted in September.

[0072] From December to February in the pre-planting period, the daughter seedlings are placed in a 5-degree cold storage for about two months to accumulate the chilling requirement. The mother plants are planted in March. From March to April, the temperature is controlled at 20℃ - 30℃ during the day and 10 - 15℃ at night. When the temperature rises in May, it can promote growth. The increase in the chilling requirement accumulates more hormones, which is beneficial to the reproduction of more stolons. Under normal temperature cultivation in the later stage, it can grow better.

[0073] Plant the daughter plants in March, place the daughter plants in a 5-degree cold storage for about two months to accumulate chilling requirements. From March to April, control the daytime temperature at 20°C - 30°C and the nighttime temperature at 10 - 15°C; normally plant the daughter plants in September and do not control the temperature for the old plants during the overwintering period. In the greenhouse environment, the daytime temperature does not exceed 30°C and the nighttime temperature is not lower than 5°C.

[0074] For the daughter plants planted in March, first propagate the seedlings and then bear fruits, and then compare the old plants and the new plants. Compare the normal old plants with the old plants that first propagate the seedlings and then bear fruits. The old plants can bloom and bear fruits again, and promote flower growth by combining temperature and photoperiod management.

[0075] (Innovation Point 1) For the daughter plants planted in March, terminate the propagation of stolons at the end of July, and form new flower buds after being maintained in a low-temperature and short-day environment. This method is applicable to high-altitude areas. The old plants with new inflorescences can be transplanted in advance to areas without flower bud differentiation environment to bloom and bear fruits again, realizing early flowering and fruiting in areas where flower bud differentiation cannot be advanced in advance.

[0076] (Innovation Point 2)Trim the old plants at the end of July and tidy up the lateral buds. From September to October, under the low-temperature and short-day environment, bear fruits from New Year's Day to the Spring Festival, and the yield of the old plants is higher than that of the new plants. In the same year in September, for the old plants and new plants, carry out normal water, fertilizer, temperature, humidity and photoperiod management. The tillering number of the old plants is more than that of the new plants (daughter plants), and the number of flower buds is more than that of the new plants (daughter plants).

[0077] It can be seen that the mode of first propagating the seedlings and then bearing fruits in the present invention can not only ensure the quantity and quality of strawberry stolon propagation, but also obtain the yield of fresh fruits in the off-season of the market (from New Year's Day to the Spring Festival), improve the facility utilization rate, and save costs and increase efficiency. The strawberries propagate seedlings in spring and summer and bear fruits in autumn and winter, without affecting the normal growth and fruit quality of strawberry plants in the second year.

[0078] The above has described the present invention in detail. For those skilled in the art, without departing from the purpose and scope of the present invention and without unnecessary experiments, the present invention can be implemented within a relatively wide range under equivalent parameters, concentrations and conditions. Although the present invention gives special embodiments, it should be understood that the present invention can be further improved. In short, according to the principle of the present invention, this application intends to include any changes, uses or improvements to the present invention, including changes made by using conventional techniques known in the art that are outside the scope disclosed in this application. According to the scope of the following appended claims, some basic features can be applied.

Claims

1. A method for annual production of strawberries with a lifting type and high density, which is characterized in that It includes the steps of planting strawberry mother plants on a lifting high rack after the accumulation of chilling requirement, promoting the occurrence of stolons by long-day high-temperature treatment, guiding and pressing the daughter plants formed on the stolons for cutting and inserting into the plug trays placed on the high rack, and cultivating until the root systems are strong and then cutting off the stolons; the obtained daughter plants are new plants, and the mother plants are old plants; treating the new plants and the old plants with low temperature and short-day in autumn and winter to make them both flower and bear fruit in autumn and winter of the same year, and mature and be harvested in the strawberry fruit growth season of the next year.

2. The method according to claim 1, wherein: The accumulation of chilling requirement is a low-temperature treatment at 5 °C for more than two months.

3. The method according to claim 1 or 2, characterized in that: The long-day high-temperature treatment is 16 hours of sunshine per day, with the daytime temperature controlled at 28 - 30 °C and the nighttime temperature at 18 - 20 °C.

4. The method according to claim 3, wherein: The time for guiding and pressing is from May to late June.

5. The method according to claim 3, characterized in that: For the guiding and pressing, each mother plant forms 10 - 15 daughter plants.

6. The method according to claim 3, wherein: For the cultivation until the root systems are strong, the cultivation conditions are more than 8 hours of light per day, the daytime temperature controlled at 28 - 30 °C, the nighttime temperature at 18 - 20 °C, and watering once every 2 - 3 days.

7. The method according to claim 3, characterized in that: For cutting off the stolons, it is 2 - 3 weeks after the guiding and pressing.

8. The method according to claim 3, characterized in that: For the low-temperature short-day treatment, the daytime temperature is 20 °C - 30 °C, and the nighttime temperature is not lower than 10 °C.

9. The method according to claim 3, characterized in that: The strawberry variety is selected from Hongyan, Sweet Charlie, and Xiangye.

10. The method according to any one of claims 1-9, characterized in that: It includes the following steps: S1. Plant the strawberry mother plants after the accumulation of chilling requirement on a lifting high rack; S2. Conduct long-day high-temperature treatment on the strawberry mother plants to promote the occurrence of stolons, guide and press the daughter plants formed on the stolons for cutting and inserting into the plug trays placed on the high rack, cultivate for 2 - 3 weeks after the guiding and pressing until the growth is strong, with more than 2 expanded leaves and more than 3 white adventitious roots showing, and then cut off the stolons. The daughter plants are the newly propagated plants, and the mother plants are the old plants; The long-day high-temperature treatment is 16 hours of sunshine per day, with the daytime temperature controlled at 28 - 30 °C and the nighttime temperature at 18 - 20 °C; For the cultivation after the guiding and pressing, the cultivation conditions are 8 hours (inclusive) or more of light per day, the daytime temperature controlled at 28 - 30 °C, the nighttime temperature at 18 - 20 °C, and watering once every 2 - 3 days; S3. Conduct low-temperature short-day treatment from September to October of the same year, control the daytime temperature at 20 °C - 30 °C, the nighttime temperature at 5 - 10 °C, and the light duration at 8 hours to promote flower bud differentiation. Both the new plants and the old plants flower from October to November and the fruits are harvested from December to February of the next year.

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