Method for regulating and controlling flowering phase of crape myrtle and application of method

Abstract

The invention discloses a lagerstroemia indica flowering phase regulation and control method and application thereof. The method comprises the steps that S1, lagerstroemia indica is subjected to daily management; s2, regulating and controlling the flowering period of the crape myrtle; s3, maintaining the lagerstroemia indica subjected to flowering phase regulation and control; wherein the step S2 comprises the following steps: S21, selecting a proper plant, and S22, performing inflorescence pruning or branch pruning treatment on the plant from mid-to-late May to late August according to a flowering phase regulation target. According to the method for regulating and controlling the flowering period of the lagerstroemia indica, the secondary flowering full-bloom period of the lagerstroemia indica is regulated and controlled to be in the middle and first ten days of September to October, the variety of woody flowering plants in major festival activities (such as national celebration) in the period is enriched, the use amount of grass flowers is reduced, the flower landscape effect is guaranteed, and meanwhile the maintenance cost is reduced. The lagerstroemia indica flowering phase regulation and control method provided by the invention is high in precision, high in practicability and convenient to popularize.

Description

Technical Field

[0001] The present application relates to the field of plant cultivation technology, and more specifically to a method for regulating the flowering period of crape myrtle and its application. Background Art

[0002] There are few species of woody flowering plants in summer and autumn in East China and Central China, and the flower landscape for major festivals (such as National Day) mainly relies on grass flowers. The extensive use of grass flowers has the following disadvantages: 1. High economic cost, 4-6 times of changing flowers each year, high costs for flower production, transportation, planting, maintenance, and replacement; 2. Unable to maintain normal long-term effects, seasonal grass flowers need to be replaced frequently, generally a grass flower has an ornamental period of about 1-3 months, and a growing period of less than a year; 3. Low ecological benefits, first, a large amount of water, fertilizer, and medicine are required during planting and maintenance, second, its biomass is much smaller than that of woody plants, and its carbon fixation capacity is significantly weaker than that of woody plants, and third, the soil fixation effect is weak.

[0003] In view of this, one of the research directions of technicians in this field is to regulate the flowering period of woody plants. Crape myrtle belongs to the genus Lagerstroemia in the Lythraceae family. It has a large number of flowers, rich flower colors, and a long flowering period. It is an important summer flowering plant. Due to the characteristics of crape myrtle that flower buds differentiate and bloom in the same year, the flowering period can be effectively extended or regulated by pruning and other measures. In recent years, relevant technical research on the regulation of crape myrtle flowering period has achieved certain results. Sha Fei, Lu Shibao, Chen Ying and others used partial branch pruning or sequential pruning (also called round pruning) to make crape myrtle bloom 2-3 rounds, but the crape myrtle treated with partial pruning or sequential pruning had a significantly reduced number of flowers during the flowering period compared to natural growth. In addition, Luo Xuemeng, Dai Qingmin and others also studied the effect of extrinsic hormones on the secondary flowering of crape myrtle.

[0004] However, in existing studies, even with the same or similar operating techniques, the regulation effects vary greatly due to differences in regions, varieties, operators, etc. Based on these studies, the applicant conducted pruning in late July and early August in an attempt to regulate the second flowering period of crape myrtles in Shanghai to the National Day period, but failed to achieve the desired effect, and the regulation effects of different varieties varied greatly.

[0005] In response to the above problems, the applicant is committed to developing a popularizable measure to regulate the flowering period of Lagerstroemia indica, which would regulate its secondary flowering period to September to mid-to-early October, so as to enrich the types of woody flowering plants during major festivals (such as National Day) during this period, reduce the use of herbaceous flowers, ensure the flower landscape effect, and reduce maintenance costs. Summary of the invention

[0006] In view of the above shortcomings of the prior art, the purpose of the present application is to provide a method for regulating the flowering period of Lagerstroemia indica and its application, so as to solve the problem that the flowering period regulation method in the prior art cannot achieve the ideal effect.

[0007] To achieve the above purpose, the present application provides a method for regulating the flowering period of Lagerstroemia indica, comprising:

[0008] S1. Carry out daily management of Crape Myrtles;

[0009] S2, regulating the flowering period of Crape Myrtles;

[0010] S3. Maintain the crape myrtles after the flowering period is regulated;

[0011] Wherein, step S2 comprises:

[0012] S21. Select suitable plants;

[0013] S22. According to the flowering period regulation target, the plants should be pruned of inflorescences or branches from mid-to-late May to late August.

[0014] Preferably, in step S2, the trimming time and the trimming amount satisfy the following formula:

[0015] D t =1.931D p +28.734A p +8.1;

[0016] Among them, D t D is the number of days from August 1 to the target flowering period. p is the number of days from August 1 to the pruning time, A p The proportion of branches of the current year (excluding inflorescences) that are pruned away;

[0017] D t , D p and A p Subject to the following restrictions:

[0018] D t and D p is an integer, D t >25, D p ≤22,8.1+1.931D p ≤D t <20.634+1.931D p ;

[0019] 0≤A p <1, when A p =0, it means pruning the inflorescence.

[0020] Preferably, when A p = 0, prune at the first full axillary bud below the inflorescence; when A p When ≥0.8, the pruned branches should have at least 3 axillary buds.

[0021] Preferably, by the method for regulating the flowering period of crape myrtle, the secondary flowering period of crape myrtle is regulated to September to early to mid-October.

[0022] Preferably, in step S21, the selected plants should meet the following requirements: there is no obstruction in the vertical direction of the crown, the plants are healthy and strong, and have no obvious diseases or insect pests.

[0023] Preferably, step S1 comprises:

[0024] S11. Focus on the prevention and control of crape myrtle weevils, powdery mildew and crape myrtle aphids, including:

[0025] The prevention and control methods of the crape myrtle pear weevil are as follows: spray pesticides for prevention after budding in spring; if pests have occurred, spray pesticides once every 10-15 days, and spray pesticides 2-3 times in succession; cut off all fruit clusters before the capsules crack in mid-to-early November of the previous year;

[0026] The prevention and control method of powdery mildew is: spray the pesticide for prevention after budding in spring. If the disease has occurred, spray the pesticide once every 7-10 days, and spray the pesticide 2-3 times continuously;

[0027] The method for preventing and controlling crape myrtle aphids is: after budding in spring, spray the pesticide for prevention. If insect pests have occurred, spray the pesticide once every 10-15 days, and spray the pesticide 2-3 times in a row.

[0028] Preferably, step S1 further includes:

[0029] S12. Apply organic fertilizer to crape myrtles in the winter of the previous year at a rate of 8-12 kg / m 2 , the fertilization method is broadcasting, and the organic fertilizer is fully mixed with the topsoil in combination with loosening the soil;

[0030] S13. Soil moisture management: If the soil is not dry, do not water; if you water, water thoroughly;

[0031] S14. In the winter of the previous year, the branches of the current year should be severely pruned, and the dense branches, diseased and insect-infested branches, weak branches, senescent branches and dead branches should be thinned out. Severe pruning means pruning off 3 / 4-4 / 5 of the branch growth in the current year.

[0032] Preferably, step S3 comprises:

[0033] S31. Within 1-7 days after pruning, spray insecticides and fungicides to prevent the occurrence of pests and diseases such as crape myrtle weevil, powdery mildew and crape myrtle aphid.

[0034] Preferably, step S3 further includes:

[0035] S32. Fertilization: After the flowering period of crape myrtle is regulated, apply a phosphorus-potassium compound fertilizer once. The fertilization method is hole application or ring application. The fertilizer holes and fertilizer rings are at the outer edge of the vertical projection of the crown.

[0036] The present application also provides the application of the method for regulating the flowering period of crape myrtle in regulating the flowering period of crape myrtle.

[0037] The method for regulating the flowering period of Lagerstroemia indica provided in this application has the following technical effects:

[0038] 1. The method for regulating the flowering period of crape myrtle provided in the present application regulates the secondary flowering period of crape myrtle to September to early to mid-October, so as to enrich the types of woody flowering plants in major festivals (such as National Day) during this period, reduce the amount of grass flowers used, ensure the flower landscape effect, and reduce maintenance costs.

[0039] 2. The method for regulating the flowering period of Lagerstroemia indica provided in this application is highly accurate, practical and easy to promote.

[0040] The concept, specific structure and technical effects of the present application will be further described below in conjunction with the accompanying drawings to fully understand the purpose, characteristics and effects of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 This is the 'Velvet' state diagram of Putuo Xincun Road on September 27, 2020 in the application case of Example 1.

[0042] Figure 2 The 'Velvet' status diagram of Zhijiang Middle Road, Jing'an on September 27, 2020 in the first scene of Example 3.

[0043] Figure 3 This is the 'velvet' state on September 9, 2020, at Zhijiang Middle Road, Jing'an, in the second scene of Example 3.

[0044] Figure 4 This is the 'Velvet' state diagram of Putuo Xincun Road on September 10, 2020 in the third scene of Example 3.

[0045] Figure 5 This is the WT-01 status diagram of the Bund in Huangpu District on September 15, 2020 in the fourth scenario of Example 3.

[0046] Figure 6 This is the 'Pink Crystal' status diagram of Songjiang Sixian Road on September 23, 2022 in the fifth scene of Example 3.

[0047] Figure 7 This is the 'Velvet' state diagram of Pudong New Area Pudian Road in the sixth scenario of Example 3 on September 25, 2023.

[0048] Figure 8This is the 'red fireball' state diagram of Youle Road, Changning on September 25, 2023 in the seventh scene of Example 3. DETAILED DESCRIPTION

[0049] The following describes the embodiments of the present application through specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification. The present application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0050] Some exemplary embodiments of the present application are described for the purpose of explanation, and it should be understood that the present application may be implemented in other ways not specifically shown in the drawings.

[0051] The present application provides a method for regulating the flowering period of Lagerstroemia indica, which mainly includes the following three steps:

[0052] S1. Carry out daily management of Crape Myrtles;

[0053] S2, regulating the flowering period of Crape Myrtles;

[0054] S3. Maintain the crape myrtle after the flowering period is regulated.

[0055] The main purpose of step S1 is to make the plants grow healthily, such as carrying out scientific and standardized fertilization, water management, pruning and pest and disease control on the plants. It should be understood that daily management plans that can achieve the purpose of making the plants grow healthily are applicable to this application.

[0056] Specifically, step S1 includes: S11, focusing on preventing and controlling crape myrtle weevil, powdery mildew and crape myrtle aphid.

[0057] Among them, the crape myrtle pear weevil harms tender shoots and prevents the plant from differentiating flower buds. The prevention and control method of the crape myrtle pear weevil is: spray the pesticide for prevention after budding in spring; if insect pests have occurred, spray the pesticide once every 10-15 days, and spray the pesticide 2-3 times continuously, preferably in the morning and evening; cut off all fruit sequences before the capsules crack in mid-to-early November of the previous year, which can destroy the overwintering place of the crape myrtle pear weevil and effectively reduce the insect population density next year. The pesticides for preventing and controlling the crape myrtle pear weevil can be selected from insecticides such as highly effective cypermethrin, emamectin benzoate, and chlorpyrifos. It should be understood that the pesticides that can be used to prevent and control the crape myrtle pear weevil are applicable to this application and are not limited to the several listed.

[0058] Powdery mildew harms the whole plant, affecting growth and flowering. The method of controlling powdery mildew is: after germination in spring, spray the agent for prevention. If the disease has occurred, spray the agent once every 7-10 days, spray the agent 2-3 times continuously, and the spraying time is easy to be in the morning and evening. The agent for controlling powdery mildew can be selected from fungicides such as triadimefon wettable powder, myclobutanil or tebuconazole. It should be understood that the agent that can be used to control powdery mildew is applicable to this application, and is not limited to the several listed.

[0059] The crape myrtle aphid induces sooty mold, affecting growth and flowering. The method for controlling the crape myrtle aphid is: after budding in spring, spray the agent for prevention. If the pest has occurred, spray the agent once every 10-15 days, and spray the agent 2-3 times continuously. The spraying time is preferably in the morning and evening. The agent for controlling the crape myrtle aphid can be selected from insecticides such as imidacloprid wettable powder (which can effectively control the insect population density and sooty mold occurrence throughout the year), acetamiprid emulsifiable concentrate, thiamethoxam water dispersible granules, and high-efficiency chlorpyrifos. It should be understood that the agents that can be used to control the crape myrtle aphid are all applicable to this application, and are not limited to the several listed.

[0060] Step S1 also includes: S12, applying organic fertilizer to the crape myrtle in the winter of the previous year, with the fertilizer application rate being 8-12 kg / m 2 , preferably 10kg / m 2 The fertilization method is to spread the fertilizer and mix the organic fertilizer with the topsoil in combination with loosening the soil. The main purpose of fertilization is to increase soil nutrients and air permeability.

[0061] Step S1 also includes: S13, soil moisture management: if the soil is not dry, do not water; if water is applied, water thoroughly.

[0062] Step S1 also includes: S14, performing heavy pruning on the current year's branches in the previous winter, and removing overcrowded branches, diseased and insect-infested branches, weak branches, senescent branches and dead branches, wherein heavy pruning is to prune away 3 / 4-4 / 5 of the current year's growth of the branches. The purpose of heavy pruning is to concentrate nutrient supply.

[0063] Step S2, i.e., regulating the flowering period of Crape Myrtle, is the key point of this application, and specifically includes the following two steps.

[0064] Step S21, select suitable plants. The selected plants should meet the following requirements: dark green and shiny leaves, strong branches, and no obvious pests and diseases and mechanical damage; Lagerstroemia indica likes light, and sufficient light is conducive to its growth and flower bud differentiation. Practice has shown that shading will affect the effect of flowering period regulation, so the growth environment of the selected plants should be sufficient in light, and preferably the plants with no obstruction in the vertical direction of the crown.

[0065] Step S22: According to the flowering period regulation target, the plants are pruned for inflorescence or branches from mid-to-late May to late August. More specifically, the pruning time and pruning amount preferably satisfy the following formula:

[0066] D t =1.931D p +28.734A p +8.1;

[0067] Among them, D t is the number of days from August 1 to the target flowering period (for example, if the target flowering period is set to September 25, then D t =56), D p is the number of days from August 1 to the pruning time (for example, if pruning is on August 20, then D p = 20; if pruning is done on July 25, then D p =-6), A p The proportion of branches (excluding inflorescences) pruned off in the current year (0≤A p <1, when A p =0, inflorescence pruning);

[0068] D t , D p and A p Subject to the following restrictions:

[0069] D t and D p is an integer, D t >25, D p ≤22,8.1+1.931D p ≤D t <20.634+1.931D p .

[0070] When A p = 0, prune at the first full axillary bud below the inflorescence, more specifically, prune about 0.5 cm above the first full axillary bud below the inflorescence; when A p ≥0.8, the pruned branches should have at least 3 axillary buds, that is, when A p ≥0.8, if according to A p If the branches have less than 3 axillary buds after pruning, they should be pruned in a way that retains 3 axillary buds instead of A. p The actual value is trimmed.

[0071] To facilitate understanding of the above formula, an example is given below:

[0072] If the target flowering start date is set to September 25 and the pruning time is set to August 20, then D t =56, D p =20, D t =56 and D p =20Substitute into the above formula Dt =1.931D p +28.734A p +8.1, which is an A p =0.32, that is, 0.32 of the branches of the current year are pruned. In other words, if 0.32 of the branches of the current year (close to 1 / 3 of the branches of the current year) are pruned on August 20, the plant can reach the beginning of the second flowering period around September 25.

[0073] Through the above-mentioned method of regulating the flowering period of crape myrtle, the secondary flowering period of crape myrtle is regulated to September to mid-to-early October, which enriches the types of woody flowering plants during this period, reduces the amount of herbaceous flowers, ensures the flower landscape effect, and reduces maintenance costs.

[0074] After pruning the crape myrtle, the subsequent maintenance step S3 is also very important, specifically in terms of fertilization, water management, and pest and disease control.

[0075] Regarding pest control, specifically step S31, within 1-7 days after pruning, spraying pesticides and fungicides to prevent the occurrence of pests and diseases such as crape myrtle weevil, powdery mildew and crape myrtle aphid.

[0076] The prevention method of crape myrtle pear weevil is: spray the pesticide within 1-7 days after pruning to prevent crape myrtle pear weevil. The pesticide for preventing crape myrtle pear weevil can be selected from insecticides such as highly effective cypermethrin, emamectin benzoate, and chlorpyrifos. It should be understood that the pesticides that can be used to prevent crape myrtle pear weevil are applicable to this application, and are not limited to the listed ones.

[0077] The method for preventing powdery mildew is to spray the pesticide within 1-7 days after pruning to prevent powdery mildew. The pesticide for preventing powdery mildew can be triadimefon wettable powder, myclobutanil or tebuconazole and other fungicides. It should be understood that the pesticides that can be used to prevent and control powdery mildew are applicable to this application, and are not limited to the listed ones.

[0078] The prevention method of crape myrtle aphid is to spray the pesticide within 1-7 days after pruning to prevent crape myrtle aphid. The pesticide for preventing crape myrtle aphid can be selected from imidacloprid wettable powder (which can effectively control the insect population density and the occurrence of sooty mold disease throughout the year), acetamiprid emulsifiable concentrate, thiamethoxam water dispersible granules, high-efficiency cypermethrin and other insecticides. It should be understood that the pesticides that can be used to prevent crape myrtle aphid are applicable to this application and are not limited to the listed ones.

[0079] Regarding fertilization, specifically, step S32, fertilization: after the flowering period of the crape myrtle is regulated, a partial phosphorus-potassium compound fertilizer is applied once to promote flower bud differentiation. The fertilization method is hole fertilization or ring fertilization, and the fertilization hole and fertilization ring are at the outer edge of the vertical projection of the crown. Watering should be done immediately after fertilization.

[0080] Regarding water management, specifically, the implementation of step S33, the flowering period regulation operation is in the hot and dry season. If the temperature is greater than 35°C, watering should be guaranteed at least once a day, and the watering should be thorough. The lack of water can be judged by observing the soil condition (cracks, whitening, etc.) and the state of the plant (leaves are dull, wilting, etc.), and the watering frequency can be appropriately increased. Watering should be carried out after sunset or before sunrise. In the absence of water accumulation, ensuring sufficient water supply is the key to the secondary flower bud differentiation of Crape Myrtle.

[0081] In addition, the present application also provides an application of the method for regulating the flowering period of crape myrtle in regulating the flowering period of crape myrtle. By means of the above method for regulating the flowering period of crape myrtle, the second flowering period of crape myrtle is regulated to September to early to mid-October.

[0082] Example 1

[0083] This embodiment provides a specific implementation of the method for regulating the flowering period of crape myrtle, wherein the crape myrtle variety is crape myrtle 'Velvet', and the target flowering start date D is set. t September 25, pruning time D p For August 20, D t =59 and D p =22Substitute into the above formula D t =1.931D p +28.734A p +8.1, which is an A p =0.32.

[0084] The method for regulating the flowering period of Lagerstroemia indica in this embodiment comprises the following steps:

[0085] S11. Control the crape myrtle weevil, powdery mildew and crape myrtle aphid. The control method for the crape myrtle weevil is: spray high-efficiency cypermethrin for prevention after budding in spring; if pests have occurred, spray high-efficiency cypermethrin once every 10-15 days, spray high-efficiency cypermethrin 2-3 times continuously, and spray in the morning and evening; cut off all fruit clusters before the capsules crack in mid-to-early November of the previous year. The control method for powdery mildew is: spray amyclobutanil for prevention after budding in spring; if the disease has occurred, spray amyclobutanil once every 7-10 days, spray 2-3 times continuously, and spray in the morning and evening. The prevention and control method of crape myrtle aphids is: after budding in spring, spray imidacloprid wettable powder for prevention. If insect pests have occurred, spray imidacloprid wettable powder once every 10-15 days, and spray imidacloprid wettable powder 2-3 times continuously, spraying in the morning and evening.

[0086] S12. Apply organic fertilizer to crape myrtles in the winter of the previous year at a rate of 10 kg / m 2 The method of fertilization is broadcasting, and the organic fertilizer is fully mixed with the topsoil by loosening the soil.

[0087] S13. Soil moisture management: If the soil is not dry, do not water; if you water, water thoroughly.

[0088] S14. In the winter of the previous year, the branches of the current year should be severely pruned, and the dense branches, diseased and insect-infested branches, weak branches, senescent branches and dead branches should be thinned out. Severe pruning means pruning off 3 / 4 of the branch growth in the current year.

[0089] S21. Select suitable plants. The selected plants should have dark green and shiny leaves, strong branches, and no obvious diseases, insect pests, or mechanical damage; the selected plants should grow in an environment with sufficient sunlight and no vertical obstructions to the crown.

[0090] S22. According to the flowering period control target, 0.32 of the branches grown that year were pruned on August 20.

[0091] S31. Within 1-7 days after pruning, spray insecticides and fungicides to prevent the occurrence of crape myrtle pear weevil, powdery mildew and crape myrtle spotted aphid. The prevention method of crape myrtle pear weevil is to spray high-efficiency cypermethrin to prevent crape myrtle pear weevil within 1-7 days after pruning. The prevention method of powdery mildew is to spray myclobutanil to prevent powdery mildew within 1-7 days after pruning. The prevention method of crape myrtle spotted aphid is to spray imidacloprid wettable powder to prevent crape myrtle spotted aphid within 1-7 days after pruning.

[0092] S32. Fertilization: After the flowering period of crape myrtle is regulated, apply a phosphorus-potassium compound fertilizer once. The fertilization method is hole-fertilization. The fertilizer holes are at the outer edge of the vertical projection of the crown. Water should be applied immediately after fertilization.

[0093] S33. The implementation of flowering period regulation operation is in the hot and dry season. If the temperature is greater than 35℃, watering should be guaranteed at least once a day, and the watering should be thorough. The lack of water can be judged by observing the soil condition (cracks, whitening, etc.) and the state of the plants (dull leaves, wilting, etc.), and the frequency of watering should be appropriately increased. Watering should be carried out after sunset or before sunrise.

[0094] By using the above-mentioned method for regulating the flowering period of crape myrtle, the starting date of the second flowering of crape myrtle can be regulated to around September 25. Figure 1 This is an application case of this embodiment, which shows the blooming state of Lagerstroemia indica 'Velvet' on Xincun Road, Putuo on September 27.

[0095] Example 2

[0096] This embodiment provides another specific implementation of the method for regulating the flowering period of crape myrtle, wherein the crape myrtle variety is selected as crape myrtle 'Red Rocket', and the target flowering start date D is set. t September 16, pruning time D p For August 14, D t =47 and D p=14Substitute into the above formula D t =1.931D p +28.734A p +8.1, which is an A p =0.41.

[0097] The method for regulating the flowering period of Lagerstroemia indica in this embodiment comprises the following steps:

[0098] S11. Control the crape myrtle weevil, powdery mildew and crape myrtle aphid. The control method for the crape myrtle weevil is: spray emamectin benzoate for prevention after budding in spring; if pests have occurred, spray emamectin benzoate once every 10-15 days, spray emamectin benzoate 2-3 times continuously, and spray in the morning and evening; cut off all fruit clusters before the capsules crack in mid-to-early November of the previous year. The control method for powdery mildew is: spray triadimefon wettable powder for prevention after budding in spring; if the disease has occurred, spray triadimefon wettable powder once every 7-10 days, spray emamectin benzoate 2-3 times continuously, and spray in the morning and evening. The prevention and control method of crape myrtle aphids is: after budding in spring, spray acetamiprid emulsifiable concentrate for prevention. If insect pests have occurred, spray acetamiprid emulsifiable concentrate once every 10-15 days, and spray acetamiprid emulsifiable concentrate 2-3 times continuously, spraying in the morning and evening.

[0099] S12. In the winter of the previous year, organic fertilizer was applied to the crape myrtle at a rate of 12 kg / m 2 The method of fertilization is broadcasting, and the organic fertilizer is fully mixed with the topsoil by loosening the soil.

[0100] S13. Soil moisture management: If the soil is not dry, do not water; if you water, water thoroughly.

[0101] S14. In the winter of the previous year, the branches of the current year should be severely pruned, and the dense branches, diseased and insect-infested branches, weak branches, senescent branches and dead branches should be thinned out. Severe pruning means pruning off 4 / 5 of the branch growth in the current year.

[0102] S21. Select suitable plants. The selected plants should have dark green and shiny leaves, strong branches, and no obvious diseases, insect pests, or mechanical damage; the selected plants should grow in an environment with sufficient sunlight and no vertical obstructions to the crown.

[0103] S22. According to the flowering period control target, 0.41 of the branches grown that year were pruned on August 14.

[0104] S31. Within 1-7 days after pruning, spray insecticides and fungicides to prevent the occurrence of crape myrtle weevil, powdery mildew and crape myrtle aphid. The prevention method of crape myrtle weevil is to spray emamectin benzoate within 1-7 days after pruning to prevent crape myrtle weevil. The prevention method of powdery mildew is to spray triadimefon wettable powder within 1-7 days after pruning to prevent powdery mildew. The prevention method of crape myrtle aphid is to spray acetamiprid emulsifiable concentrate within 1-7 days after pruning to prevent crape myrtle aphid.

[0105] S32. Fertilization: After the flowering period of crape myrtle is regulated, apply a phosphorus-potassium compound fertilizer once. The fertilization method is ring application. The fertilizer ring is at the outer edge of the vertical projection of the crown. Water should be applied immediately after fertilization.

[0106] S33. The implementation of flowering period regulation operation is in the hot and dry season. If the temperature is greater than 35℃, watering should be guaranteed at least once a day, and the watering should be thorough. The lack of water can be judged by observing the soil condition (cracks, whitening, etc.) and the state of the plants (dull leaves, wilting, etc.), and the frequency of watering should be appropriately increased. Watering should be carried out after sunset or before sunrise.

[0107] By using the above-mentioned method for regulating the flowering period of crape myrtle, the starting date of the second flowering of crape myrtle can be regulated to around September 16.

[0108] Example 3

[0109] In this embodiment, the above-mentioned method for regulating the flowering period of crape myrtle is applied to an actual situation. The specific steps are similar to those in Embodiments 1-2. The following table shows the treatment results of crape myrtle in multiple locations. Figure 1-7 The blooming status of the crape myrtle in 7 scenes in Example 3 is shown. Specifically, Figure 1 The blooming status of 'Velvet' on Zhijiang Middle Road, Jing'an on September 27, 2020 in the first scenario is shown, in which 0.32 of the current year's branches were pruned on August 20, 2020; Figure 2 The blooming status of 'Velvet' on Zhijiang Middle Road, Jing'an on September 9, 2020 in the second scenario is shown, in which 0.3 of the current year's branches were pruned on August 10, 2020; Figure 3 The blooming status of 'Velvet' on Putuo Xincun Road on September 10, 2020 in the third scenario is shown, in which 0.47 of the current year's branches were pruned on August 10, 2020; Figure 4 The blooming status of WT-01 on September 15, 2020, in the fourth scenario is shown in the Bund, Huangpu District, where 0.3 of the current year’s branches were pruned on August 10, 2020; Figure 5 The fifth scene shows the blooming state of 'Pink Quartz' on Songjiang Sixian Road on September 23, 2022, in which 0.19 of the current year's branches were pruned on August 22, 2022; Figure 6The picture shows the blooming status of 'Velvet' on Pudian Road, Pudong New Area on September 25, 2023 in the sixth scenario, where only the inflorescence was cut on August 21, 2023; Figure 7 The blooming status of 'Red Fireball' on Youle Road, Changning on September 25, 2023 in the seventh scene is shown, in which 0.32 of the current year's branches were pruned on August 20, 2023.

[0110]

[0111] It can be seen from the above results that the method for regulating the flowering period of crape myrtle in the present application can regulate the secondary flowering period of crape myrtle to an ideal effect according to the target flowering start period, enrich the types of woody flowering plants during major festivals (such as National Day) during the period, and reduce the use of herbaceous flowers.

[0112] The above embodiments are merely illustrative of the principles and effects of the present application and are not intended to limit the present application. Anyone familiar with the technology may modify or change the above embodiments without violating the spirit and scope of the present application. Therefore, all equivalent modifications or changes made by a person of ordinary skill in the art without departing from the spirit and technical ideas disclosed in the present application shall still be covered by the claims of the present application.

Claims

1. A method for regulating the flowering period of Lagerstroemia indica, characterized in that: include: S1. Carry out daily management of Crape Myrtles; S2, regulating the flowering period of Crape Myrtles; S3. Maintain the crape myrtles after the flowering period is regulated; Wherein, step S2 comprises: S21. Choose the right plants. S22. According to the flowering period regulation target, the plants should be pruned of inflorescences or branches from mid-to-late May to late August.

2. The method for regulating the flowering period of Lagerstroemia indica according to claim 1, characterized in that: In step S2, the trimming time and trimming amount satisfy the following formula: <h2 style=";text-align:left;direction:ltr">D<h2 style=";text-align:left;direction:ltr"> t <h2 style=";text-align:left;direction:ltr"> <1.931D<h2 style=";text-align:left;direction:ltr"> p <h2 style=";text-align:left;direction:ltr"> +28.734A<h2 style=";text-align:left;direction:ltr"> p <h2 style=";text-align:left;direction:ltr"> +8.1; Among them, D t D is the number of days from August 1 to the target flowering period. p is the number of days from August 1 to the pruning time, A p The proportion of the branches of the current year that are pruned away, excluding the inflorescence part; D t , D p and A p Subject to the following restrictions: D t and D p is an integer, D t >25, D p ≤22,8.1+1.931D p ≤D t <20.634+1.931D p ; 0≤A p <1, when A p =0, it means pruning the inflorescence.

3. The method for regulating the flowering period of Lagerstroemia indica according to claim 2, characterized in that: When A p = 0, prune at the first full axillary bud below the inflorescence; when A p When ≥0.8, the pruned branches should have at least 3 axillary buds.

4. The method for regulating the flowering period of Lagerstroemia indica according to claim 2 or 3, characterized in that: By using the method for regulating the flowering period of crape myrtle, the secondary flowering period of crape myrtle is regulated to September to early to middle October.

5. The method for regulating the flowering period of Lagerstroemia indica according to claim 1, characterized in that: In step S21, the selected plants should meet the following requirements: there is no obstruction in the vertical direction of the crown, the plants are healthy and strong, and have no obvious diseases or insect pests.

6. The method for regulating the flowering period of Lagerstroemia indica according to claim 1, characterized in that: Step S1 includes: S11. Focus on the prevention and control of crape myrtle weevils, powdery mildew and crape myrtle aphids, including: The prevention and control methods of the crape myrtle pear weevil are as follows: spray pesticides for prevention after budding in spring; if pests have occurred, spray pesticides once every 10-15 days, and spray pesticides 2-3 times in succession; cut off all fruit clusters before the capsules crack in mid-to-early November of the previous year; The prevention and control method of powdery mildew is: spray the pesticide for prevention after budding in spring. If the disease has occurred, spray the pesticide once every 7-10 days, and spray the pesticide 2-3 times continuously; The method for preventing and controlling crape myrtle aphids is: after budding in spring, spray the pesticide for prevention. If insect pests have occurred, spray the pesticide once every 10-15 days, and spray the pesticide 2-3 times in a row.

7. The method for regulating the flowering period of Lagerstroemia indica according to claim 1, characterized in that: Step S1 also includes: S12. Apply organic fertilizer to crape myrtles in the winter of the previous year at a rate of 8-12 kg / m 2 , the fertilization method is broadcasting, and the organic fertilizer is fully mixed with the topsoil in combination with loosening the soil; S13. Soil moisture management: If the soil is not dry, do not water; if you water, water thoroughly; S14. In the winter of the previous year, the branches of the current year should be severely pruned, and the dense branches, diseased and insect-infested branches, weak branches, senescent branches and dead branches should be thinned out. Severe pruning means pruning off 3 / 4-4 / 5 of the branch growth in the current year.

8. The method for regulating the flowering period of Lagerstroemia indica according to claim 1, characterized in that: Step S3 includes: S31. Within 1-7 days after pruning, spray insecticides and fungicides to prevent the occurrence of crape myrtle pear weevil, powdery mildew and crape myrtle aphids.

9. The method for regulating the flowering period of Lagerstroemia indica according to claim 1, characterized in that: Step S3 also includes: S32. Fertilization: After the flowering period of crape myrtle is regulated, apply a phosphorus-potassium compound fertilizer once. The fertilization method is hole application or ring application. The fertilizer holes and fertilizer rings are at the outer edge of the vertical projection of the crown.

10. Use of the method for regulating the flowering period of Lagerstroemia indica according to any one of claims 1 to 9 in regulating the flowering period of Lagerstroemia indica.

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