Method for prolonging ornamental period of autumn color leaf garden trees

Abstract

This application provides a method for extending the viewing period of autumn-colored foliage trees in gardens, and a compound plant regulator that can delay the shedding of leaves from colorful-leaved trees in northern regions during autumn. This application primarily addresses the problem of short viewing periods for some autumn-colored foliage tree species in northern regions after they change color in autumn, and researches a method to extend the viewing period of autumn-colored foliage trees in gardens, specifically extending the viewing period of ash trees such as *Fraxinus chinensis* (Autumn Purple Ash). Ash American ' Autumn Purple'), Acer genus such as Acer truncatum ( Maple truncated During the autumn viewing season, highly ornamental trees with colorful foliage such as Ficus microcarpa promote the color change of autumn leaves in garden trees and delay their leaf fall, extending the time when autumn leaves remain on the trees. This also enhances the low-temperature resistance of ornamental plants, improves their overall resistance to diseases and pests, and promotes their growth.

Description

Technical Field

[0001] This invention relates to the field of agricultural cultivation technology, specifically a method for extending the viewing period of autumn-colored garden trees. Background Technology

[0002] To address the issue of short viewing periods for some autumn-colored foliage tree species in northern regions after their autumn foliage changes, the viewing period for species such as *Fraxinus chinensis* and *Fraxinus chinensis* has been extended. Fraxinus americana 'Autumn Purple' ), such as the Acer genus (Acer truncatum) Acer truncatum For highly ornamental foliage trees such as Bunge, during the autumn viewing season, most existing plant growth regulators are designed to promote plant growth, flowering, and fruit setting, and are rarely used to delay the color change and leaf fall in autumn. In cases where most growth regulators are used alone during the autumn viewing season for ornamental foliage trees, those skilled in the art have found that they are only suitable for delaying leaf fall, and cannot simultaneously promote color change and delay leaf fall.

[0003] Therefore, there is an urgent need to develop a method to extend the viewing period of autumn foliage in garden trees, as well as a variety of plant growth regulators to promote the color change of autumn foliage in garden trees and delay their leaf fall, thus extending the time when autumn foliage hangs on the trees. Summary of the Invention

[0004] To address the aforementioned technical problems, the present invention aims to provide a method for extending the viewing period of autumn-colored garden trees. This method can promote the color change of autumn leaves and delay their fall, thus prolonging the time the autumn leaves remain on the trees. It also enhances the low-temperature resistance of ornamental plants, improves their overall resistance to diseases and pests, and promotes their growth.

[0005] This invention provides a method for extending the viewing period of autumn foliage in garden trees, specifically comprising: uniformly spraying a plant growth regulator on the leaves in late September, wherein the plant growth regulator comprises a mixed solution of the following components: 6BA 100-300ppm + gibberellic acid 50-100ppm + sodium silicate 100-300ppm + brassinolide 0.2-0.3ppm; the mixed solution is prepared by first preparing solutions of the above concentrations separately and then mixing them in equal volume ratios; uniformly spraying a plant growth regulator on the leaves in mid-October, wherein the plant growth regulator comprises a mixed solution of the following components: gibberellic acid 50-100ppm + sodium silicate 100-300ppm + indoleacetic acid (IAA) 800-1200ppm + brassinolide 0.1-0.8ppm; the mixed solution is prepared by first preparing solutions of the above concentrations separately and then mixing them in equal volume ratios.

[0006] The present invention also provides a method for extending the viewing period of autumn foliage in garden trees, comprising the following steps: (1) When the branches of trees begin to sprout in spring, spray the branches alternately with 10% imidacloprid at 100-150 times dilution and 5% abamectin at 50-100 times dilution. Strengthen the topdressing during this period to ensure vigorous growth of leaves throughout the year. Apply 30 kg of N:P:K compound fertilizer with a ratio of 30-10-20 per mu. (2) In late May, spray the leaves evenly with a 1000-fold dilution of 30% methomyl to prevent Verticillium wilt and root diseases; (3) In early July, when the trunk borer is at its peak, spray the trunk and branches with pesticide. The pesticide formula is a mixed solution containing the following components: 10% cypermethrin at 100 times dilution, 10% imidacloprid at 150 times dilution, 45% chlorpyrifos at 100 times dilution, and pure polyether modified silicone oil at 30 times dilution. The mixed solution is prepared by first preparing the solutions of the above concentrations separately and then mixing them in equal volume proportions. (4) In late September, the leaves are evenly sprayed with a plant growth regulator, which is a mixed solution of the following components: 100-300 ppm cytokinin (6BA) + 50-100 ppm gibberellic acid + 100-300 ppm sodium silicate + 0.2-0.3 ppm brassinolide; the mixed solution is prepared by first preparing the solutions of the above concentrations separately and then mixing them in equal volume ratios. (5) In mid-October, the leaves are evenly sprayed with a plant growth regulator, which is a mixed solution of the following components: gibberellic acid 50-100ppm + sodium silicate 100-300ppm + indoleacetic acid (IAA) 800-1200ppm + brassinolide 0.1-0.8ppm; the mixed solution is prepared by first preparing the solutions of the above concentrations separately and then mixing them in equal volume proportions.

[0007] Furthermore, step (1) specifically involves alternately spraying 10% imidacloprid at a dilution of 100 times and 5% abamectin at a dilution of 50 times, once in the morning and once in the evening, with an interval of 3 days between sprayings, for a total of 3 sprays.

[0008] Furthermore, step (2) specifically involves spraying the leaves evenly with a 1000-fold dilution of 30% methomyl, once in the morning and once in the evening, with an interval of 3 days between sprays, for a total of 3 sprays.

[0009] Furthermore, step (3) specifically involves spraying the tree trunk with pesticide, spraying only the trunk to avoid contact with the leaves and causing pesticide damage. Spray once in the morning (1 time), and spray once every 3 days for a total of 2 times.

[0010] Furthermore, step (4) specifically involves spraying plant growth regulators evenly on the leaves in late September, once in the morning and once in the evening, with a 3-day interval between sprays, for a total of 3 sprays. After each application of the plant growth regulator, apply water-soluble fertilizer with an N:P:K ratio of 20-20-20, using drip irrigation around the tree pit, at a rate of 10 kg of fertilizer per acre. Fertilization is carried out together with watering.

[0011] Furthermore, step (5) specifically involves spraying plant growth regulators evenly on the leaves in mid-October, once in the morning and once in the evening, with an interval of 2 days between sprays, for a total of 2-5 sprays, depending on the leaf fall, until 80% of the leaves have fallen. After each application of the plant growth regulator, apply a high phosphorus and potassium water-soluble fertilizer with an N:P:K ratio of 10-30-20, using drip irrigation around the tree pit, at a rate of 10 kg of fertilizer per acre, with fertilization and watering done together.

[0012] The present invention also provides a compound plant regulator for extending the viewing period of autumn foliage trees in northern regions. The plant regulator comprises a mixed solution of the following components: 100-300 ppm cytokinin (6BA) + 50-100 ppm gibberellic acid + 100-300 ppm sodium silicate + 0.2-0.3 ppm brassinolide; the mixed solution is prepared by first preparing solutions of the above concentrations separately, and then mixing them in equal volume proportions.

[0013] The present invention also provides a compound plant regulator for extending the viewing period of autumn foliage trees in northern regions. The plant regulator comprises a mixed solution of the following components: gibberellic acid 50-100ppm + sodium silicate 100-300ppm + indoleacetic acid (IAA) 800-1200ppm + brassinolide 0.1-0.8ppm. The mixed solution is prepared by first preparing solutions of the above concentrations separately and then mixing them in equal volume proportions.

[0014] This invention also provides a compound plant regulator for extending the viewing period of autumn foliage trees in northern regions. The plant regulator comprises a mixed solution of the following components: 100-300 ppm cytokinin (6BA) + 50-100 ppm gibberellic acid. The mixed solution is prepared by first preparing solutions of the above concentrations separately and then mixing them in equal volume ratios.

[0015] The present invention also provides the application of any of the foregoing claims in any of the following aspects: (1) Application in extending the autumn foliage viewing period of Ash genus plants such as Autumn Purple and White Ash; (2) Application in extending the autumn foliage viewing period of maple species such as Acer truncatum; (3) Application in improving the low-temperature resistance of autumn-colored garden trees; (4) Application in increasing the total chlorophyll content, soluble protein content, catalase content and superoxide dismutase content of leaves of autumn-colored garden trees during the autumn leaf fall period; (5) Application in reducing malondialdehyde content and catalase content in leaves of autumn-colored garden trees during the autumn leaf fall period.

[0016] The beneficial effects of this application are: 1. Studies have shown that exogenous auxins can significantly improve tree growth vigor and inhibit the formation of ABA (abscisic acid) in leaves. Through years of research and experimentation, the researchers of this application have obtained a compound plant regulator that prolongs the viewing period of autumn-colored foliage trees in gardens, as well as its application method. When applied to trees, it can enhance their resistance to disease, insects, and low temperatures, especially during the autumn leaf fall period, as it can promote protoplasmic streaming in plant cells and improve cell viability.

[0017] 2. Exogenous 6-BA (6-benzylaminopurine) treatment significantly increased chlorophyll and soluble protein content in leaves, maintaining the integrity of chloroplast grana lamellae and chloroplast membrane structures; it also increased the activities of CAT (catalase) and SOD (superoxide dismutase) in leaves, thereby reducing the contents of MDA (malondialdehyde) and H2O2 (catalase). Exogenous gibberellic acid significantly increased chlorophyll content, soluble protein content, net photosynthetic rate, and Fv / Fm in leaves entering the senescence stage, alleviating the disintegration of chloroplast internal structures; it also significantly increased the activities of CAT (catalase) and SOD (superoxide dismutase) in leaves, while significantly reducing the contents of MDA (malondialdehyde) and H2O2 (catalase). In late September in northern regions, evenly spray the leaves with a plant growth regulator: 6BA 100-300ppm + gibberellic acid 50-100ppm + sodium silicate 100-300ppm + brassinolide 0.2-0.3ppm. This can improve leaf resistance, delay the damage of low temperature to tree leaves, promote photosynthesis in plants under low temperature conditions, further maintain leaf growth vigor, and inhibit the formation of ABA (abscisic acid) in leaves.

[0018] 3. In northern regions, in mid-October, a second application of the following compound plant growth regulator can promote the color change of autumn foliage trees, bringing them to their peak viewing period, while also delaying leaf fall and extending their viewing period.

[0019] 4. Experimental studies have shown that brassinolide and brassinolide also participate in the regulation of plant senescence. Plant senescence is accompanied by a decline in photosynthetic capacity and an increase in ROS content. Brassinolide and brassinolide have a regulatory effect on the senescence process of leaves. Therefore, the researchers of this application conducted a trial experiment on colorful trees in gardens in northern regions and found that spraying brassinolide and brassinolide at different times can delay the senescence stage of leaves and enhance the anti-senescence ability of trees under low temperatures to a certain extent. However, the effect of applying lactone plant regulators alone is not good. It needs to be combined with the application of 6BA and GA3 to achieve a better effect in prolonging the leaf-hanging time. In addition, we also found that the application of silicon in the plant regulators of this application has a synergistic effect. That is, sodium silicate plays multiple important roles in the compound plant regulator for prolonging the viewing period of autumn foliage trees. It mainly helps to improve leaf photosynthesis and enhance stress resistance. Combined with regulators such as 6BA and gibberellic acid, it has a better effect.

[0020] 5. In addition to the application of exogenous plant growth regulators, in recent years we have also studied the synergistic effect of combining spring and summer leaf disease and pest protection measures with fertilization measures on extending the viewing period of autumn foliage in gardens. The study found that during the spring and summer when diseases and pests are severe, the application of a certain concentration of compound agents can improve the disease and pest resistance of trees. At the same time, it also reduces the occurrence of leaf senescence and leaf drop caused by diseases and pests. Combined with fertilization measures, it can synergistically extend the viewing period of autumn foliage.

[0021] 6. In northern regions, aphids mainly appear in spring as seedlings sprout. Timely application of imidacloprid is effective for control. Summer is also the most critical period for pests and diseases, especially trunk borers, cankers, and wilt. We have found that garden trees often experience early leaf drop and decreased growth in autumn due to these pests and diseases. Therefore, applying a mixture of pure polyether-modified silicone oil, high-efficiency cypermethrin, imidacloprid, and chlorpyrifos to the trunk in summer significantly prolongs the viewing period of autumn foliage. Polyether-modified silicone oil is an excellent bark penetrant, and its use in combination promotes pesticide absorption. Furthermore, late May is primarily for preventing wilt. Spraying with a 1000-fold dilution of 30% methomyl at this time has shown through orthogonal experiments that this step effectively prolongs the viewing period of trees, significantly improves leaf vigor, and effectively prevents wilt.

[0022] 7. Fertilization management is also one of the factors affecting the viewing period of autumn foliage. Applying high-nitrogen fertilizer in spring can promote leaf growth, increase the total chlorophyll content of garden trees and leaves, and improve leaf vitality. Before the leaves begin to change color in early autumn, applying a balanced N:P:K water-soluble fertilizer can provide balanced nutrients for the plants. In conjunction with the application of plant growth regulators, the leaf hanging time can be extended. During the autumn viewing period, applying high-phosphorus and low-nitrogen water-soluble fertilizer can promote leaf color change and improve the viewing effect. Attached Figure Description

[0023] Figure 1 Outdoor comparison image showing the effect of the compound plant growth regulator of this invention on prolonging the ornamental period of Acer truncatum leaves; Figure 2 Outdoor comparison image showing the effect of the compound plant growth regulator of this invention on prolonging the ornamental period of Autumn Purple White Ash leaves; Figure 3 Physiological index analysis of Acer truncatum leaves after the first application of growth regulator; Figure 4 Physiological index analysis of Acer truncatum leaves after the second application of growth regulator; Figure 5 Physiological index analysis of Autumn Purple White Ash leaves after the first application of growth regulator; Figure 6 Analysis of physiological indicators of leaves of *Fraxinus chinensis* after the second application of growth regulator. Detailed Implementation

[0024] The following will refer to the appendices in the embodiments of the present invention. Figure 1-6 The technical solutions in the embodiments of this invention are clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention. It is worth noting that the material used in the experiments of this invention is *Elaeocarpus santalinus* (ash). Fraxinus americana 'Autumn Purple' ), such as the Acer genus, including Acer truncatum (also known as Acer truncatum) ( Acer truncatum (Bunge), the Latin name and genus name are both from the official website of the Flora of China. Different literature has different genus names. The plant is identified by referring to the Latin name and is within the scope of protection of this application. Example 1

[0025] A method for extending the viewing period of autumn foliage on garden trees includes the following steps: (1) When the branches of trees begin to sprout in spring, spray the branches alternately with 10% imidacloprid 100 times dilution and 5% abamectin 50 times dilution; apply 30 kg of N:P:K compound fertilizer with a ratio of 30-10-20 per mu; spray once in the morning and once in the evening, with an interval of 3 days, for a total of 3 sprays; (2) In late May, spray the leaves evenly with 30% methomyl at a dilution of 1000 times; spray once in the morning and once in the evening, with an interval of 3 days between sprays, for a total of 3 sprays; (3) Spray the trunk and branches with pesticide in early July. The pesticide formula is a mixed solution containing the following components: 10% cypermethrin 100 times dilution, 10% imidacloprid 150 times dilution, 45% chlorpyrifos 100 times dilution, and pure polyether modified silicone oil 30 times dilution. The mixed solution is prepared by first preparing the above concentrations separately and then mixing them in equal volume ratio. Spray once in the morning (1 time), and spray once every 3 days for a total of 2 times. (4) In late September, the leaves were evenly sprayed with a plant growth regulator, which was a mixed solution of the following components: 200 ppm cytokinin (6BA) + 80 ppm gibberellic acid + 100 ppm sodium silicate + 0.2 ppm brassinolide. The mixed solution was prepared by first preparing the solutions of the above concentrations separately and then mixing them in equal volume ratios. The plant growth regulator was sprayed once in the morning and once in the evening, with an interval of 3 days between sprays, for a total of 3 sprays. After each application of the plant growth regulator, a water-soluble fertilizer with an N:P:K ratio of 20-20-20 was applied around the tree pit using drip irrigation. The fertilizer was applied at a rate of 10 kg per mu, and the fertilization was carried out together with the watering. (5) In mid-October, the leaves are evenly sprayed with a plant growth regulator, which is a mixed solution of the following components: 100 ppm gibberellic acid + 100 ppm sodium silicate + 1000 ppm indoleacetic acid (IAA) + 0.2 ppm brassinolide. The mixed solution is prepared by first preparing the solutions of the above concentrations separately and then mixing them in equal volume ratios. Spray once in the morning and once in the evening (1 time), and spray once every 2 days for a total of 3 times. After each application of the plant growth regulator, apply a high phosphorus and potassium water-soluble fertilizer with an N:P:K ratio of 10-30-20. Apply the fertilizer around the tree hole using drip irrigation, at a rate of 10 kg per mu. Fertilization is carried out together with watering. Example 2

[0026] A method for extending the viewing period of autumn foliage trees in northern regions, including In late September, a plant growth regulator was evenly sprayed on the leaves. This plant growth regulator consisted of a mixed solution of the following components: 200 ppm cytokinin (6BA), 80 ppm gibberellic acid, 100 ppm sodium silicate, and 0.2 ppm brassinolide. The mixed solution was prepared by first preparing each of the above concentrations separately and then mixing them in equal volumes. The solution was sprayed twice a day, morning and evening, with a 3-day interval between each application, for a total of 3 applications. After each application of the plant growth regulator, a water-soluble fertilizer with an N:P:K ratio of 20-20-20 was applied around the tree pit using drip irrigation at a rate of 10 kg per acre, applied simultaneously with watering. In mid-October, another plant growth regulator was evenly sprayed on the leaves. This plant growth regulator consisted of a mixed solution of the following components: 100 ppm gibberellic acid, 100 ppm sodium silicate, and indoleacetic acid (IAA). 1000ppm + brassinolide 0.2ppm; the mixed solution is prepared by first preparing the solutions of the above concentrations separately, and then mixing them in equal volume ratios. Spray once in the morning and once in the evening (1 time), and spray once every 2 days for a total of 3 times. After each spraying of the plant growth regulator, apply a high phosphorus and potassium water-soluble fertilizer with an N:P:K ratio of 10-30-20, and apply it around the tree hole using drip irrigation. The fertilizer is 10kg per acre, and the fertilization is carried out together with watering. Example 3

[0027] A compound plant growth regulator for extending the viewing period of autumn foliage trees in northern regions, the plant growth regulator comprising a mixed solution of the following components: 200 ppm cytokinin (6BA) + 80 ppm gibberellic acid + 100 ppm sodium silicate + 0.2 ppm brassinolide; the mixed solution is prepared by first preparing solutions of the above concentrations separately, and then mixing them in equal volume proportions. Example 4

[0028] A compound plant growth regulator for extending the viewing period of autumn foliage trees in northern regions, the plant growth regulator comprising a mixed solution of the following components: gibberellic acid 100ppm + sodium silicate 100ppm + indoleacetic acid (IAA) 1000ppm + brassinolide 0.2ppm; the mixed solution is prepared by first preparing solutions of the above concentrations separately, and then mixing them in equal volume proportions. Example 5

[0029] A compound plant growth regulator for extending the viewing period of autumn-colored foliage trees such as ash or maple in northern regions, the plant growth regulator comprising a mixed solution of the following components: 200 ppm cytokinin (6BA) + 80 ppm gibberellic acid + 100 ppm sodium silicate; the mixed solution is prepared by first preparing solutions of the above concentrations separately, and then mixing them in equal volume proportions. Example 6

[0030] A compound plant growth regulator for extending the viewing period of Acer truncatum, a maple tree with autumn foliage in northern regions, comprises a mixed solution of the following components: 200 ppm cytokinin (6BA) + 0.2 ppm brassinolide, and / or 100 ppm gibberellic acid + 0.2 ppm brassinolide; the mixed solution is prepared by first preparing solutions of the above concentrations separately, and then mixing them in equal volume proportions.

[0031] Experiment 1: Effects of different plant growth regulators or combinations thereof on prolonging the ornamental period of autumn foliage plants Experimental Methods: The outdoor experiment was conducted in 2024 at the Shunyi Nursery of Beijing Flower and Tree Co., Ltd. Ecological Technology Branch, Shunyi District, Beijing. This application studies the effects of different plant growth regulators or their combinations on prolonging the viewing period of autumn-colored foliage plants (species 1: Acer truncatum, species 2: Fraxinus chinensis) and seeking the optimal combination. Twelve-year-old autumn-colored foliage plants with uniform growth were selected for the outdoor experiment. The plant growth regulators are listed in Table 1 below. This experiment only considers different plant growth regulators or their combinations, and does not take into account factors such as pest and disease management and fertilization methods as described in Example 1 above. The control group plants were sprayed with distilled water normally. The experimental period began on September 26th with the first application of plant growth regulators and continued until 95% of the leaves had fallen. Leaf sampling was conducted at 7:00 AM on October 15th, following the first application of the growth regulator. Intact, healthy leaves from the plants were selected and sampled together for physiological index determination, including total chlorophyll content and soluble protein content. Leaf sampling was conducted at 7:00 AM on October 22nd, following the second application of the growth regulator. Intact, healthy leaves from the plants were selected and sampled together for physiological index determination, including CAT (catalase), SOD (superoxide dismutase), MDA (malondialdehyde), and H2O2 (catalase). Each treatment was repeated in triplicate to investigate the effects of different exogenous growth regulators on the physiological indicators of autumn-colored foliage plants.

[0032] Example 1: On September 26, the leaves were evenly sprayed with a plant conditioning solution of equal volume (drug 1): 6BA 200ppm + gibberellic acid (GA3) 80ppm + sodium silicate (Si) 100ppm + brassinolide (BL) 0.2ppm, sprayed once in the morning and once in the evening (1 time), with an interval of 3 days, for a total of 3 sprays; On October 15, the leaves were evenly sprayed with a plant conditioning solution of equal volume (drug 2): gibberellic acid 100ppm + sodium silicate 100ppm + indoleacetic acid (IAA) 1000ppm + brassinolide (BR) 0.2ppm, sprayed once in the morning and once in the evening (1 time), with an interval of 2 days, for a total of 3 sprays; Experiments 1-5: The spraying time, concentration, and frequency were the same as in Example 1, only the components of drug 1 and drug 2 were replaced (see Table 1 in order).

[0033] Table 1. Experimental groups with different exogenous plant growth regulators Experimental results: from Figure 1-2 The outdoor control figures of the compound plant regulator of Example 1 of the present invention on extending the ornamental period of Acer truncatum and Fraxinus chinensis leaves show that the compound plant regulator of Example 1 of the present invention can significantly extend the ornamental period of Acer truncatum and Fraxinus chinensis leaves. The leaves of Acer truncatum were sprayed with the first compound plant regulator on September 26 and the second compound plant regulator on October 15. By November 1, the CK control group had almost all changed color and most of the leaves had fallen. However, the Acer truncatum in the experimental group of Example 1 was still growing well and no obvious leaf drop was observed. The leaves of the experimental group only began to gradually change color on November 8. After three consecutive days of strong winds from November 6 to 8, the experimental group only had a small number of fallen leaves and some of them began to change color (the leaves of the CK group had all fallen). On November 24, it was observed that nearly half of the leaves of the experimental group remained. The ornamental period of Acer truncatum in the experimental group was delayed by about one month compared with the control group, which achieved a significant effect.

[0034] Meanwhile, the same plant growth regulator was sprayed on the Autumn Purple White Ash at the same time, using the same method as Acer truncatum. On October 19, when only 20% of the leaves remained in the control group, the experimental group had just begun to shed its leaves. By October 24, the control group had almost completely shed its leaves. Although the experimental group had been subjected to freezing (-3℃) and heavy frost damage since the 20th, as well as two consecutive days of winds of force 6-8, the number of leaves remaining in the experimental group was still comparable to the number observed on October 19. On November 1, it was observed that half of the leaves in the Autumn Purple White Ash experimental group still remained.

[0035] Figure 3As shown, exogenous auxin can significantly improve tree growth vigor, inhibit the formation of ABA (abscisic acid) in leaves, prolong the ornamental period, and enhance the stress resistance of tree leaves. Sampling results were obtained after the first application of the plant growth regulator and before the second application. Physiological indicators of Acer truncatum leaves were measured, including total chlorophyll content and soluble protein content. Example 1 showed significant differences from Experiments 1-5 and the CK control group. Spraying with exogenous 6BA 200ppm + gibberellic acid (GA3) 80ppm + sodium silicate (Si) 100ppm + brassinolide (BL) 0.2ppm significantly increased the chlorophyll content and soluble protein content of leaves entering the senescent stage, thereby further improving the net photosynthetic rate and Fv / Fm, and alleviating the disintegration of chloroplast internal structures. This is consistent with actual observation data. The CK control group, which was not sprayed with plant growth regulators, showed significant leaf drop, higher leaf discoloration, and a significant decrease in total chlorophyll content. This application demonstrates that the exogenous plant regulators can effectively improve the autumn anti-aging properties of Acer truncatum leaves and enhance their low-temperature resistance. A comparison of the exogenous plant regulator groups in Examples 1-5 shows that the combination in Example 1 is more effective than adding one or two individual regulators. Furthermore, the 6BA+GA3+Si combination in Example 1 and the combination of 6BA+BR in the first spray and GA3+BL in the second spray in Example 3 also showed superior effects, demonstrating a significant effect on extending the ornamental period of Acer truncatum and improving the tree's resistance to adverse conditions.

[0036] Figure 4As shown, the leaf sampling and measurement results after the second application of the regulator indicated that the combination of gibberellic acid 100ppm + sodium silicate 100ppm + indoleacetic acid (IAA) 1000ppm + brassinolide (BR) 0.2% in Example 1... Spraying at ppm significantly improved the stress resistance of leaves in the late senescence stage and delayed leaf drop. Physiological indicators such as CAT (catalase), SOD (superoxide dismutase), MDA (malondialdehyde), and H2O2 (catalase) were measured to determine the effects of different exogenous plant regulators on the physiological indicators of autumn-flowering foliage plants. Leaf samples from Example 1 showed lower MDA and H2O2 levels and higher CAT and SOD levels, indicating that the combination of exogenous plant regulators significantly improved plant growth vitality and antioxidant enzyme activity, and also exhibited better low-temperature tolerance. The treatment group in Example 1 reduced H2O2 and MDA levels in the leaves, demonstrating that the application of regulators reduced the impact of low-temperature stress on Acer truncatum. After treatment, the intracellular H2O2 content in Acer truncatum leaf cells was significantly reduced, alleviating membrane peroxidation damage and reducing MDA accumulation, thus mitigating and reducing low-temperature damage. Therefore, the treatment group exhibited a longer leaf-hanging period, thereby extending its ornamental leaf period. Compared with the use of one or two plant regulators alone in Examples 1-5, the combination application of plant regulators in Example 1 of the present invention has a better technical effect.

[0037] Figure 5-6 By comparing the physiological indicators of the leaves of *Fraxinus chinensis*, we concluded that Example 1 of this application also has better effects. It has better effects in improving the stress resistance of leaves at the end of senescence, improving the growth vitality of plants, delaying leaf fall, and extending the ornamental period of leaves. In addition, Example 1 also has better effects, while the effects of Examples 2-5 are not ideal.

[0038] Experiment 2: Analysis of Factors Affecting the Extension of the Autumn Foliage Viewing Period of Acer truncatum Experimental Methods: This experiment, using *Acer truncatum* as an example, aimed to analyze the factors influencing the extension of the autumn foliage viewing period and to determine the optimal combination. The experiment was conducted in 2024 at a nursery in Shunyi. Twelve-year-old *Acer truncatum* plants with uniform autumn foliage were selected for the outdoor experiment. All methods described in Example 1 of this application were used, with only the corresponding parameters of the following multi-factor, multi-level treatments replaced. The first plant regulator (drug 1) A (Level 1: 6BA 300ppm + GA3 100ppm + Si 300ppm + BL 0.3ppm, Level 2: 6BA 200ppm + GA3 80ppm + Si 100ppm + BL 0.2ppm) and the second plant regulator (drug 2) B (Level 1: GA3 50ppm + Si 100ppm + IAA 800ppm + BR 0.5ppm, Level 2: GA3 100ppm + Si 100ppm + IAA 1000ppm + BR 0.2ppm) were used. ppm), Spring and Summer Pest and Disease Control C (Level 1: Spring 10% imidacloprid 100x + 5% abamectin 50x; July 10% cypermethrin 100x, 10% imidacloprid 150x, 45% chlorpyrifos 100x; Level 2: Spring 10% imidacloprid 100x + 5% abamectin 50x; May 30% cypermethrin 1000x; July 10% cypermethrin 100x, 10% imidacloprid 150x, 45% chlorpyrifos 100x, pure polyether modified silicone oil 30x), Fertilizer Management Measures D (Level 1: Spring topdressing with 30kg N:P:K ratio 30-10-20 compound fertilizer per mu, September after spraying plant growth regulator, apply N:P: K ratio is 20-20-20 water-soluble fertilizer, applied around the tree hole by drip irrigation, 10 kg of fertilizer per mu. After spraying the plant regulator in October, apply N:P:K ratio of 10-30-20 high phosphorus and potassium water-soluble fertilizer, applied around the tree hole by drip irrigation, 10 kg of fertilizer per mu; Level 2: Apply 30 kg of N:P:K ratio of 20-20-20 compound fertilizer per mu in spring, apply N:P:K ratio of 30-10-20 water-soluble fertilizer in September, 20 kg of fertilizer per mu, apply N:P:K ratio of 20-10-10 water-soluble fertilizer in October, 20 kg of fertilizer per mu) Four conditions are variables, select the optimal combination, L8 (42) orthogonal table.The experiment was conducted according to the factors and levels in Table 2, with 8 treatments, each repeated 3 times. Leaf samples were taken at 7:00 AM on October 15th after the first application of the regulator. Intact and healthy leaves of the plants were selected and mixed for sampling and brought back to the laboratory for physiological index determination of total chlorophyll content (mg / g). Leaf samples were taken at 7:00 AM on October 22nd after the second application of the regulator. Intact and healthy leaves of the plants were selected and mixed for sampling and brought back to the laboratory for physiological index determination of MDA (nmol / mL). The experiment aimed to explore the effects of different exogenous regulators on the physiological indicators of autumn foliage plants.

[0039] Table 2. Orthogonal Experiment of Factors Affecting the Extension of the Autumn Foliage Viewing Period of Acer truncatum

[0040] Experimental Results: As shown in the table above, the most significant factor influencing the extension of the autumn foliage viewing period of *Acer truncatum* is the application of plant growth regulators, especially the first plant growth regulator formulation in Example 1. This formulation effectively increased chlorophyll content in leaves and reduced low-temperature damage to leaf membranes during the autumn low-temperature leaf fall period, thereby enhancing leaf vitality and extending the leaf hanging time. The optimal scheme affecting the total chlorophyll content of *Acer truncatum* autumn foliage is A2B2C2D1, with the following order of influence: A (first plant growth regulator (drug 1)) > C (spring and summer pest and disease control) > B (second plant growth regulator (drug 2)) > D (fertilization management measures). Specifically, the first spray consisted of 6BA 200ppm + GA3 80ppm + Si 100ppm + BL 0.2ppm, and the second spray consisted of GA3 100ppm + Si 100ppm + IAA 1000ppm + BR 0.2ppm. In spring, apply 10% imidacloprid at a dilution of 100 times + 5% abamectin at a dilution of 50 times; in May, apply 30% cypermethrin at a dilution of 1000 times; in July, apply 10% cypermethrin at a dilution of 100 times, 10% imidacloprid at a dilution of 150 times, 45% chlorpyrifos at a dilution of 100 times, and pure polyether modified silicone oil at a dilution of 30 times; in spring, apply 30 kg of N:P:K compound fertilizer with a ratio of 30-10-20 per mu; after spraying the first plant growth regulator in September, apply water-soluble fertilizer with a ratio of 20-20-20 per mu using drip irrigation around the tree pit, at a rate of 10 kg per mu; after spraying the second plant growth regulator in October, apply water-soluble fertilizer with a ratio of 10-30-20 per mu using drip irrigation around the tree pit, at a rate of 10 kg per mu.

[0041] Furthermore, the optimal scheme affecting the MDA content of autumn leaves of Acer truncatum is A2B1C2D1, with the order of influence of each factor being: A (first plant regulator (drug 1)) > B (second plant regulator (drug 2)) > C (spring and summer pest and disease control) >> D (fertilization management measures). This is basically consistent with the change pattern of total chlorophyll. The first plant regulator formulation in Example 1 showed a reduction in MDA content and mitigation of low-temperature damage during the autumn low-temperature leaf fall period.

[0042] 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 extending the viewing period of autumn-colored foliage in garden trees, characterized in that, Specifically, it includes: In late September, the leaves are evenly sprayed with a plant growth regulator, which is a mixed solution of the following components: 6BA 100-300ppm + gibberellic acid 50-100ppm + sodium silicate 100-300ppm + brassinolide 0.2-0.3ppm; the mixed solution is prepared by first preparing the solutions of the above concentrations separately, and then mixing them in equal volume ratios. In mid-October, the leaves are evenly sprayed with a plant growth regulator, which is a mixed solution of the following components: gibberellic acid 50-100ppm + sodium silicate 100-300ppm + indoleacetic acid (IAA) 800-1200ppm + brassinolide 0.1-0.8ppm; the mixed solution is prepared by first preparing the solutions of the above concentrations separately, and then mixing them in equal volume ratios. The garden trees are either ash or maple species.

2. The method for extending the viewing period of autumn-colored foliage trees in gardens as described in claim 1, characterized in that, It also includes the following steps: (1) In spring, when the branches of trees begin to sprout, aphids should be controlled during the period when the branches are newly unfolding leaves. Spray 10% imidacloprid at 100-150 times dilution and 5% abamectin at 50-100 times dilution alternately. Apply 30 kg of N:P:K compound fertilizer with a ratio of 30-10-20 per mu as top dressing. (2) In late May, spray the leaves evenly with a 1000-fold dilution of 30% methomyl; (3) Spray the trunk and branches with pesticide in early June or early July. The pesticide formula is a mixed solution including the following components: 10% cypermethrin 100 times dilution, 10% imidacloprid 150 times dilution, 45% chlorpyrifos 100 times dilution, and pure polyether modified silicone oil 30 times dilution. The mixed solution is prepared by first preparing the above concentrations separately and then mixing them in equal volume proportions.

3. The method for extending the viewing period of autumn-colored foliage trees in gardens as described in claim 2, characterized in that, The specific step (1) involves alternately spraying 10% imidacloprid at 100 times dilution and 5% abamectin at 50 times dilution, once in the morning and once in the evening, with an interval of 3 days between sprays, for a total of 3 sprays.

4. The method for extending the viewing period of autumn-colored foliage trees in gardens as described in claim 2, characterized in that, Step (2) specifically involves spraying the leaves evenly with a 1000-fold dilution of 30% methomyl, once in the morning and once in the evening, with an interval of 3 days between sprays, for a total of 3 sprays.

5. The method for extending the viewing period of autumn-colored foliage trees in gardens as described in claim 2, characterized in that, The specific step (3) involves spraying the tree trunk with pesticide, only spraying the trunk to avoid contact with the leaves and causing pesticide damage. Spray once in the morning and once every 3 days for a total of 2 times.

6. The method for extending the viewing period of autumn-colored foliage trees in gardens as described in claim 2, characterized in that, Specifically, in late September, the leaves were evenly sprayed with plant growth regulators, once in the morning and once in the evening, with an interval of 3 days between each application, for a total of 3 applications.

7. The method for extending the viewing period of autumn-colored foliage trees in gardens as described in claim 2, characterized in that, Specifically, in mid-October, spray the leaves evenly with a plant growth regulator, once in the morning and once in the evening, with an interval of 2 days between each application, for a total of 2-5 applications, depending on the leaf fall, until 80% of the leaves have fallen.

8. The method for extending the viewing period of autumn-colored foliage trees in gardens as described in claim 6, characterized in that, After spraying the plant growth regulator in late September, apply a water-soluble fertilizer with an N:P:K ratio of 20-20-20. Apply the fertilizer around the tree pit using drip irrigation, at a rate of 10 kg per acre. Fertilization should be done together with watering.

9. The method for extending the viewing period of autumn-colored foliage trees in gardens as described in claim 7, characterized in that, After spraying the plant growth regulator in mid-October, apply a high-phosphorus and potassium water-soluble fertilizer with an N:P:K ratio of 10-30-20. Apply the fertilizer around the tree pit using drip irrigation, at a rate of 10 kg per acre. Fertilization should be done together with watering.

10. The application of any one of claims 1-9 in any of the following aspects: (1) Application in improving the low-temperature resistance of autumn foliage garden trees; (2) Application in increasing the total chlorophyll content, soluble protein content, catalase content and superoxide dismutase content of leaves of autumn-colored garden trees during the autumn leaf fall period; (3) Application in reducing malondialdehyde content and catalase content in leaves of autumn-colored garden trees during the autumn leaf fall period.

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