A method for early cultivation of a kiwi pollination male plant

Abstract

The present application relates to the technical field of fruit tree cultivation, and discloses a kind of kiwi pollination male plant's early culture method, the present application aims at the technical problems such as uneven maturation of branch, disorder of dormancy rhythm, dispersed lag of germination and flowering, and misalignment of male and female flowering period of kiwi male plant in southern warm winter production area, constructs year-round closed-loop control system: complete retraction pruning within 7 days after flowering period, directional cultivation of strong pollination mother branch; light girdling is carried out on the base of pollination mother branch from late June to early July, and the growth of branches is controlled to unify lignification and maturation; plant leaf fall regulator is sprayed or leaf pruning is used in winter to force the tree to enter deep dormancy synchronously; early spring, according to the cold requirement grade of variety, monocyane solution is used to break dormancy accurately, and germination fertilizer and water are used for protection; the present application solves the problems of uneven maturation of branch, disorder of dormancy rhythm, dispersed lag of germination and flowering, and misalignment of male and female flowering period of kiwi male plant in prior art, and the adaptability of prior art to warm winter production area is poor.

Description

Technical Field

[0001] This invention relates to the field of fruit tree cultivation technology, and in particular to a method for promoting early cultivation of pollinated male kiwifruit plants. Background Technology

[0002] Kiwifruit is a perennial, dioecious, deciduous fruit tree. Natural pollination in orchards highly depends on sufficient, highly active pollen provided by male plants. The matching of flowering times between male and female plants directly affects fruit set and quality, making it a core element of kiwifruit cultivation management. Currently, research and supporting solutions for phenological regulation, flowering promotion, and fruit retention in kiwifruit cultivation largely focus on the main female plants. Specific targeted regulation techniques for pollinating male plants have long been lacking. In production practice, male plants are generally managed using conventional natural methods, lacking standardized year-round cultivation and management procedures.

[0003] Under the natural management model, male kiwifruit plants lack standardized post-flowering pruning and flowering branch cultivation. After flowering, branches are allowed to grow naturally, resulting in excessive shoot growth in summer and autumn. The lignification process and maturity of different branches vary significantly, leading to low uniformity of flower bud differentiation and large fluctuations in pollen production and activity, making it impossible to consistently and stably guarantee the pollination needs of the entire orchard.

[0004] In southern regions such as Guangxi, Yunnan, and Guangdong, where winter temperatures are low, and in northern regions where warm winters occur, the effective accumulation of low temperatures under natural conditions is insufficient to meet the dormancy requirements of male trees. Relying solely on natural leaf fall is insufficient to induce trees to enter a deep dormancy state simultaneously. In production, delayed leaf fall and the phenomenon of some branches remaining evergreen overwintering often occur, resulting in disordered tree dormancy rhythms, dispersed dormancy start and end times, and uneven dormancy depths among different plants and even different branches of the same plant. This creates hidden dangers for budding and flowering management in the following spring.

[0005] Insufficient dormancy accumulation and disordered dormancy rhythm further lead to the dispersed spring budding time of male plants and the overall delayed flowering period, making it difficult to effectively overlap with the peak flowering period of the main female plants. During the female flower opening stage, sufficient supply of highly active pollen cannot be obtained, resulting in insufficient pollination and directly causing problems such as decreased fruit set rate and increased proportion of deformed fruit. This is a long-term industry pain point that restricts the improvement of kiwi fruit planting benefits in warm winter production areas in the south.

[0006] Existing flowering time regulators and field operation protocols are mostly designed for female plants, lacking a comprehensive technical system that integrates pruning to control excessive growth, dormancy induction, and dormancy breaking to promote flowering in male plants. Simply adjusting the phenological period of female plants or applying indiscriminate control to both sexes fails to achieve precise and targeted regulation of male flowering time, making it difficult to address the core issue of asynchronous flowering between male and female plants. Furthermore, conventional dormancy regulation and dormancy breaking techniques are primarily suited to northern regions with high cold-demand production. When applied to southern regions with insufficient winter temperatures, the dormancy depth often fails to meet expectations, resulting in weak and unstable effects in promoting early flowering, and a lack of standardized operational parameters to support large-scale application. Summary of the Invention

[0007] The present invention aims to provide a method for promoting early cultivation of male kiwifruit plants that are pollinated, in order to solve the problems of uneven maturity of male kiwifruit plant branches, disordered dormancy rhythm, delayed budding and flowering, mismatch between male and female flowering periods, and poor adaptability of the existing technology to warm winter production areas.

[0008] To achieve the above objectives, the present invention provides the following method:

[0009] The present invention provides a method for promoting early cultivation of male pollinated kiwifruit plants:

[0010] S1. Post-flowering pruning and targeted cultivation of pollinating mother branches: Complete the pruning of the entire orchard within 7 days after the flowering period of the pollinated male kiwifruit plants. Shorten all the old flower branches that have finished flowering in the current year, and uniformly retain the branch length of 30cm to 40cm, with 4 to 6 plump and strong buds on each branch; at the same time, remove weak branches, overlapping branches, crossing branches and water sprouts in the inner canopy of the tree.

[0011] S2. Summer ringing to control excessive growth and promote uniform lignification and maturation of branches: During the window period from late June to early July each year when new shoots stop elongating, choose a sunny and rainless day to lightly ring the base of the current year's healthy pollinating mother branches. The ringing width is 1mm to 2mm, and the cutting depth reaches the surface of the xylem, cutting only the phloem without damaging the xylem vessels.

[0012] S3. Forced dormancy in winter to unify the dormancy rhythm of the tree: Select a sunny and windless environment, and use a plant leaf drop regulator to spray the entire male kiwi fruit plant evenly until all leaves are evenly moistened and the liquid does not drip. Alternatively, use pruning with leaves to stop the vegetative growth of the tree and force the tree to enter deep dormancy simultaneously.

[0013] S4. Precise dormancy breaking with cyanamide to achieve concentrated and early budding and flowering: Select windless and rainless weather, determine the application window according to the chilling requirement level of the male kiwifruit pollinating plants, and prepare a cyanamide aqueous solution of the corresponding concentration 30 to 40 days before the local normal natural budding period. Spray the entire pollinating mother branch evenly, focusing on soaking the buds, until the buds are moist but not dripping. Apply budding fertilizer after application, and irrigate in case of drought.

[0014] Furthermore, in step S1, the shortening and pruning operation shortens the aging flower branches to within 50cm on each side of the main vine; after removing ineffective branches, the ventilation and light conditions of the tree canopy are improved, the tree nutrients are concentrated to induce the sprouting of new nutrient branches in summer, and the new nutrient branches are cultivated into pollination mother branches for use in flowering and pollination the following year.

[0015] Furthermore, in step S2, the location of the light girdling treatment is 5cm to 10cm from the base of the healthy pollinating mother branch of the current year to the main vine attachment point; the light girdling treatment blocks the return flow of photosynthetic products to the roots, so that nutrients are concentrated in the upper part of the branch and the buds, accelerating the lignification process of the branch and unifying the maturity of the branches throughout the garden.

[0016] Furthermore, in step S3, the plant leaf drop regulator is sprayed in mid-November each year; the plant leaf drop regulator is a mixture of 300 times diluted ethephon and 1000 times diluted S-inducer, or a 3% (w / w) ethephon aqueous solution; the 300 times diluted ethephon is prepared by diluting 40% (w / w) ethephon aqueous solution by 300 times, and the 1000 times diluted S-inducer is prepared by diluting 10% (w / w) S-inducer aqueous solution by 1000 times; after spraying, the plant leaf drop rate reaches more than 90% in early December, and the tree enters dormancy 20 to 30 days earlier.

[0017] Furthermore, in step S3, the pruning with leaves is performed in early December each year; during pruning with leaves, the healthy pollinating mother branches of the current year are shortened, leaving a branch length of 30cm to 40cm, with 4 to 6 plump buds on each branch, while simultaneously removing weak branches, overlapping branches, crossing branches and overly vigorous branches in the inner canopy of the tree, thereby forcing the tree to enter dormancy early by blocking vegetative growth.

[0018] Furthermore, in step S4, the cooling requirement level is classified based on the cumulative hours of low temperature at ≤7.2℃: the cumulative hours of low temperature ≤600 hours are low cooling requirement varieties, corresponding to the application window period in early to mid-January; the cumulative hours of low temperature 600 to 1000 hours are medium cooling requirement varieties, corresponding to the application window period in mid to late January; and the cumulative hours of low temperature ≥1000 hours are high cooling requirement varieties, corresponding to the application window period in early to mid-February.

[0019] Furthermore, in step S4, the concentration of the cyanamide aqueous solution is determined according to the cooling requirement level: for low cooling requirement varieties, the cyanamide aqueous solution with a mass fraction of 1% to 1.2% is prepared; for medium cooling requirement varieties, the cyanamide aqueous solution with a mass fraction of 1.2% to 1.5% is prepared; and for high cooling requirement varieties, the cyanamide aqueous solution with a mass fraction of 1.5% to 2.5% is prepared.

[0020] Furthermore, in step S4, the irrigation operation maintains the relative water holding capacity of the soil around the tree at 60% to 70%; localized over-spraying is avoided during the application of pesticides.

[0021] Furthermore, the method is applicable to areas in the south where low temperatures are scarce in winter, as well as to large-scale kiwifruit cultivation areas in the north during warm winter years.

[0022] The beneficial effects of this invention are as follows: By constructing a year-round closed-loop regulation system that includes post-flowering pruning for shoot growth, summer girdling to control vigorous mature branches, forced synchronous dormancy in winter, and precise dormancy breaking with cyanamide in early spring, this invention can achieve uniform lignification and maturation of male kiwifruit branches, unify the dormancy start time and dormancy depth of all trees in the orchard, promote concentrated bud germination and uniform and earlier flowering, and stably advance the peak flowering period of male trees by 5 to 15 days, accurately matching the peak flowering period of the main female trees. This effectively solves the industry problem of misaligned male and female flowering periods and insufficient pollination in warm winter production areas. At the same time, the targeted cultivation of robust pollinating mother branches can improve flower bud quality and pollen activity, helping to increase the fruit setting rate and reduce the incidence of deformed fruit in the orchard. The entire technology is suitable for planting scenarios in southern regions with low winter temperatures and northern regions with warm winters. It is easy to operate, cost-controllable, and highly safe, and has good value for large-scale promotion and application. Attached Figure Description

[0023] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0024] Figure 1 This is a schematic diagram of a method for promoting early cultivation of male pollinated kiwifruit plants according to an embodiment of the present invention;

[0025] Figure 2 The germination status diagram of pollinated male plants treated with cyanamide and the control provided in this embodiment of the invention;

[0026] Figure 3 This is a diagram showing the branching status of pollinating male plants treated with cyanamide and the control, provided in an embodiment of the present invention.

[0027] Figure 4The diagram shows the flowering status of pollinating male plants treated with cyanamide and the control group, as provided in this embodiment of the invention. Detailed Implementation

[0028] To enable those skilled in the art to better understand the present invention, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] The terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this invention are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, apparatus, product, or end that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or ends.

[0030] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0031] Existing flowering time regulators and field operation protocols are mostly designed for female plants, lacking a comprehensive technical system that integrates pruning to control excessive growth, dormancy induction, and dormancy breaking to promote flowering in male plants. Simply adjusting the phenological period of female plants or applying indiscriminate control to both sexes fails to achieve precise and targeted regulation of male flowering time, making it difficult to address the core issue of asynchronous flowering between male and female plants. Furthermore, conventional dormancy regulation and dormancy breaking techniques are primarily suited to northern regions with high cold-demand production. When applied to southern regions with insufficient winter temperatures, the dormancy depth often fails to meet expectations, resulting in weak and unstable effects in promoting early flowering, and a lack of standardized operational parameters to support large-scale application.

[0032] The present invention aims to provide a method for promoting early cultivation of male kiwifruit plants that are pollinated, in order to solve the problems of uneven maturity of male kiwifruit plant branches, disordered dormancy rhythm, delayed budding and flowering, mismatch between male and female flowering periods, and poor adaptability of the existing technology to warm winter production areas.

[0033] like Figure 1 As shown in the figure, a specific embodiment of the present invention provides a method for promoting early cultivation of male pollinated kiwifruit plants, the specific steps of which are as follows:

[0034] S1: Post-flowering pruning and targeted cultivation of pollinating mother branches. Complete the pruning of the entire orchard within 7 days after the flowering period of the male kiwifruit plants that have finished pollinating. Shorten all the old flower branches that have finished flowering this year, and uniformly retain the branch length of 30cm to 40cm, with 4 to 6 plump and strong buds on each branch; at the same time, remove weak branches, overlapping branches, crossing branches and water sprouts in the inner canopy of the tree.

[0035] In this embodiment of the invention, the shortening and pruning operation reduces aging flower branches to within 50cm on each side of the main vine. By promptly removing aging flower branches after flowering, the tree's stored nitrogen nutrients are prevented from being continuously consumed and the supply of endogenous hormones is diverted. Combined with the removal of ineffective branches in the inner canopy, the ventilation and light penetration of the canopy can be effectively improved, the nutrient competition pressure inside the canopy can be reduced, and the tree's nutrients are concentrated to induce the growth of strong new nutrient branches in summer. These new nutrient branches are then oriented to become dedicated pollination mother branches for the following year. From the perspective of tree structure, this ensures the fullness of flower buds and the robustness of branches, laying a nutritional foundation for the subsequent uniform differentiation of flower buds.

[0036] S2: Summer girdling controls excessive growth and promotes uniform lignification and maturation of branches. During the critical window period from late June to early July each year when new shoots stop elongating, choose a sunny, rainless day to lightly girdle the base of healthy pollinating mother branches of the current year. The girdling width is 1mm to 2mm, and the cutting depth reaches the surface of the xylem, cutting only the phloem without damaging the xylem vessels.

[0037] In this embodiment of the invention, the specific location for mild girdling is 5cm to 10cm from the base of a healthy pollinating mother branch of the current year, away from the main vine's attachment point. During the operation, a special girdling knife is used to precisely control the cutting depth, cutting only the phloem sieve tubes while completely preserving the xylem vessels to ensure the normal upward supply of water and mineral elements to the roots. This operation can block the backflow of photosynthetic products to the roots, allowing nutrients to continuously accumulate in the upper part of the branches and buds, increasing the carbon-nitrogen ratio in the upper part of the branches, promoting an increase in endogenous abscisic acid content and a decrease in gibberellin content, effectively inhibiting excessive growth of summer and autumn shoots, accelerating the lignification process of branches, achieving uniform maturity of branches throughout the orchard, and synchronizing the timing of flower bud differentiation, thus completely solving the problem of uneven branch maturity.

[0038] S3: Forced dormancy in winter to unify the tree's dormancy rhythm. Select a sunny, windless environment and spray the entire male kiwifruit plant with a plant leaf drop regulator evenly until all leaves are evenly moistened and the solution no longer drips. Alternatively, use pruning with leaves to stop the tree's vegetative growth and force the tree to enter deep dormancy simultaneously.

[0039] In this embodiment of the invention, when using chemical defoliation, the spraying time is mid-November each year. The plant defoliation regulator can be a mixture of 300 times ethephon and 1000 times S-inducer, or a 3% ethephon aqueous solution. The 300 times ethephon solution is prepared by diluting 40% ethephon aqueous solution by 300 times, and the 1000 times S-inducer solution is prepared by diluting 10% S-inducer aqueous solution by 1000 times. After spraying, it can accelerate the synthesis of endogenous ethylene in the leaves, rapidly decompose the chlorophyll in the leaves, block photosynthetic metabolism, force the vegetative growth of the tree to terminate early, make the tree uniformly perceive the low temperature signal, upregulate the expression of dormancy-related genes, accumulate abscisic acid, artificially make up for the deficiency of insufficient effective low temperature accumulation in the warm winter areas of the south. Usually, the leaf drop rate of the plants can reach more than 90% by early December, and the trees enter dormancy 20 to 30 days earlier, unifying the dormancy start time and dormancy depth of the entire garden. When using the leaf-bearing pruning method, the time for implementation is in early December each year. During pruning, the healthy pollinating mother branches of the current year are shortened, leaving a branch length of 30cm to 40cm, and each branch retains 4 to 6 plump buds. At the same time, weak branches, overlapping branches, crossing branches and water sprouts in the inner canopy of the tree are removed. The tree’s vegetative growth is blocked by physical means, forcing the tree to enter a dormant state early.

[0040] S4: Cyanamide precisely breaks dormancy, achieving concentrated and earlier budding and flowering. Choose a windless and rainless day, and determine the application window based on the chilling requirement level of the male kiwifruit pollinating plant variety. Prepare a cyanamide solution of the corresponding concentration 30 to 40 days before the local normal natural budding period, and spray it evenly on all pollinating mother branches, focusing on soaking the buds until they are moist but not dripping. After application, apply budding fertilizer and irrigate in case of drought.

[0041] In this embodiment of the invention, the chilling requirement level is classified based on the cumulative hours of low temperature at ≤7.2℃: varieties with a cumulative low temperature of ≤600 hours are classified as low chilling requirement varieties, corresponding to the application window period in early to mid-January, using a 1%–1.2% (w / w) cyanamide aqueous solution; varieties with a cumulative low temperature of 600–1000 hours are classified as medium chilling requirement varieties, corresponding to the application window period in mid to late January, using a 1.2%–1.5% (w / w) cyanamide aqueous solution; varieties with a cumulative low temperature of ≥1000 hours are classified as high chilling requirement varieties, corresponding to the application window period in early to mid-February, using a 1.5%–2.5% (w / w) cyanamide aqueous solution. During application, all pollinating branches should be sprayed evenly, focusing on the buds, avoiding localized overspraying that could damage the buds; spraying cyanamide can inhibit the activity of catalase inside the buds, breaking the physiological barrier of deep dormancy in the buds, and promoting concentrated germination and uniform bud formation in male plants. After applying the pesticide, use a quick-acting bud-germinating fertilizer to supplement nutrients. In case of drought, irrigate in time to maintain the relative water holding capacity of the soil around the tree at 60% to 70%, ensuring that the pesticide can fully penetrate and that the buds are adequately hydrated. This step can reliably advance the budding period of male trees by 7 to 20 days and advance the overall flowering period by 5 to 15 days. The flowering period is concentrated, uniform, and without any trailing, precisely matching the phenological period of the main female trees. At the same time, it can avoid the risk of frost damage to the budding shoots caused by late spring cold snaps.

[0042] To further verify the actual regulatory effect of the method of this invention, the following field trials of two male kiwifruit varieties with different chilling requirements are used to specifically illustrate the implementation effect of this invention. The comparative effects of bud break, branching, and flowering of the experimental plants are shown below. Figure 2 , Figure 3 , Figure 4 As shown.

[0043] Example 1: Application of low chilling requirement 'Hongyang' kiwifruit male plants in promoting early cultivation

[0044] This experiment was conducted at the kiwifruit cultivar garden of the Guangxi Institute of Botany. The experimental subject was an 8-year-old male pollinated 'Hongyang' kiwifruit plant. This variety has a cumulative chilling requirement of 336 hours at ≤7.2℃, which is considered a low chilling requirement variety.

[0045] According to the method described in this invention, the year-round closed-loop management is carried out as follows: S1. Post-flowering pruning: On the 5th day after the flowering period of the male 'Hongyang' plants, the pruning of the entire garden is completed. All current-year aging flower branches are shortened and pruned back, with a uniform branch length of 35cm and 5 plump and strong buds left on each branch. At the same time, weak branches, overlapping branches, crossing branches and water sprouts in the inner canopy of the tree are removed. The aging flower branches are pruned back to within 50cm on both sides of the main vine, and nutrients are concentrated to induce the sprouting of new nutrient branches in summer, which are then directionally cultivated as pollination mother branches for the following year.

[0046] S2. Summer ringing to control excessive growth: In late June, during the window period when new shoots stop elongating, choose a sunny, rainless day to lightly ring the base of a healthy pollinating mother branch of the current year, 8cm away from the main vine's attachment point. The ring width should be 1.5mm, and the cutting depth should reach the surface of the xylem, cutting only the phloem and preserving the integrity of the xylem vessels.

[0047] S3. Forced winter dormancy: In mid-November, select a sunny and windless environment and spray a mixture of 300 times ethephon and 1000 times S-inducer. The leaves of the whole plant should be evenly moistened and the solution should not drip. After spraying, the leaf drop rate of the plant will reach 92% in early December, and the tree will enter deep dormancy 25 days earlier.

[0048] S4. Precise Dormancy Breaking with Cyanamide: Four parallel treatments were set up. At 40, 30, 20, and 10 days before the local natural budding period, respectively, a 1.2% (w / w) cyanamide aqueous solution was prepared and evenly sprayed onto all pollinating branches, focusing on the buds. The standard was that the buds were moist but not dripping. After application, a fast-acting budding fertilizer was applied, and irrigation was carried out in case of drought to maintain the relative water holding capacity of the soil around the tree at 65%. A blank control group was also included, sprayed with plain water. Each treatment had five replicates, and four representative branches from each plant were selected and tagged for statistical analysis of phenological stages and budding / flowering indicators.

[0049] Based on field statistics, the phenological period regulation effect of this embodiment is shown in Table 1 below:

[0050] Table 1. Effects of breaking dormancy at different times on the phenological stage of male 'Hongyang' kiwifruit plants.

[0051]

[0052] Phenological period regulation effect: Application of the pesticide 40 days before bud break advanced the bud break onset by 3 days and the peak flowering by 4 days; application 30 days before bud break advanced the bud break onset by 2 days and the peak flowering by 4 days; application 20 days before bud break advanced the bud break onset by 2 days and the peak flowering by 3 days. Regarding bud break uniformity, the bud break duration was 25 days for the treatment 40 days before bud break, compared to 33 days for the control group, indicating a significant improvement in bud break concentration; the flowering duration was also shortened synchronously, with no obvious trailing of the flowering period. Figure 2 The budding contrast shown is consistent.

[0053] The statistical results of germination and flowering quality in this embodiment are shown in Table 2 below:

[0054] Table 2. Effects of breaking dormancy at different times on bud break and flowering of male 'Hongyang' kiwifruit plants.

[0055]

[0056] Effects on bud break and flowering quality: The bud break rate of all treatments was higher than that of the control group, with an increase of 1.85–8.74 percentage points. The highest bud break rate was achieved in the treatment 20 days before bud break, reaching 65.90%. The rate of flowering branches increased by 1.87%–11.52%, with the highest rate of flowering branches achieved in the treatment 30 days before bud break, reaching 93.46%. The rate of deformed flowers was significantly reduced, with the rate of deformed flowers in all treatments ranging from 8.44% to 13.76%, far lower than the 20.35% in the control group. The number of flowers per branch also increased simultaneously, reaching 28.13 flowers per branch in the treatment 30 days before bud break. The total pollen supply increased significantly, and the vigor of the shoots was also improved. Figure 3 As shown.

[0057] Example 2: Application of high chilling requirement 'Shimei' kiwifruit male plants in promoting early cultivation

[0058] This embodiment was conducted in the same experimental park, and the experimental subject was a 6-year-old male pollinated 'Shimei' kiwifruit plant. This variety has a cumulative chilling requirement of 1008 hours at ≤7.2℃, which is a high chilling requirement variety.

[0059] Perform year-round closed-loop management according to the method described in this invention:

[0060] S1. Post-flowering pruning: On the 6th day after the flowering period of the male 'Shimei' trees, complete the pruning of the entire garden. Shorten all the current year's old flower branches, uniformly retaining a branch length of 38cm, and leaving 5 plump and strong buds on each branch; at the same time, remove the ineffective branches in the inner canopy of the tree and cultivate pollination mother branches for the following year.

[0061] S2. Summer ringing to control excessive growth: In early July, during the window period when new shoots stop elongating, choose a sunny and rainless day to lightly ring the base of a healthy pollinating mother branch of the current year, 7cm away from the main vine's attachment point. The ring width should be 2mm, and the cutting depth should reach the surface of the xylem, cutting only the phloem without damaging the xylem vessels.

[0062] S3. Forced dormancy in winter: In mid-November, select a sunny and windless environment and spray with a 3% ethephon solution. The leaves of the entire plant should be evenly moistened and the solution should not drip. After spraying, the leaf drop rate of the plant will reach 91% in early December, and the tree will enter deep dormancy 28 days earlier.

[0063] S4. Precise Dormancy Breaking with Cyanamide: Four parallel treatments were set up. At 40, 30, 20, and 10 days before the local natural budding period, respectively, a 2.0% (w / w) cyanamide aqueous solution was prepared and evenly sprayed onto all pollinating branches, focusing on the buds. The standard was that the buds were moist but not dripping. A fast-acting budding fertilizer was applied after the treatment, and irrigation was carried out in case of drought to maintain the relative water holding capacity of the soil around the tree at 68%. A blank control group was also set up, sprayed with plain water. Each treatment had five replicates, and four representative branches from each plant were selected and tagged for statistical analysis of phenological stages and budding / flowering indicators.

[0064] Based on field statistics, the phenological period regulation effect of this embodiment is shown in Table 3 below:

[0065] Table 3. Effects of breaking dormancy at different times on the phenological stage of male 'Shimei' kiwifruit plants.

[0066]

[0067] Phenological period regulation effect: Application of the pesticide 40 days before bud break advanced the bud break onset by 10 days and the peak flowering by 12 days; application 30 days before bud break advanced the bud break onset by 8 days and the peak flowering by 10 days; application 20 days before bud break advanced the bud break onset by 3 days and the peak flowering by 7 days. Regarding bud break uniformity, the bud break duration was 17 days for the treatment 40 days before bud break, compared to 23 days for the control group. Regarding flowering duration, the flowering duration was 16 days for the treatment 40 days before bud break, compared to 23 days for the control group. The effect of concentrated phenological period uniformity improvement was significant, and the flowering comparison effect was as follows: Figure 4 As shown.

[0068] The statistical results of germination and flowering quality in this embodiment are shown in Table 4 below:

[0069] Table 4. Effects of breaking dormancy at different times on bud break and flowering of male pollinated plants of 'Shimei' kiwifruit.

[0070]

[0071] Effects on germination and flowering quality: The germination rate of all treatments was significantly higher than that of the control group, with an increase of 4.09–15.24 percentage points. The highest germination rate was achieved in the treatment 20 days before germination, reaching 47.44%. The rate of flowering branches increased by 5.96%–25.55%, with the highest rate of flowering branches achieved in the treatment 30 days before germination, reaching 72.92%. The rate of deformed flowers was significantly reduced, with the rate of deformed flowers in all treatments ranging from 5.13% to 9.80%, far lower than the 16.22% in the control group. The number of flowers per branch also increased simultaneously, with the number of flowers per branch reaching 8.20 in the treatment 40 days before germination, effectively improving the pollen supply capacity of chilling-required varieties.

[0072] In summary, this invention, through the construction of a year-round closed-loop regulation system involving post-flowering pruning for shoot development, summer girdling to control vigorous mature branches, forced synchronous dormancy in winter, and precise dormancy breaking with cyanamide in early spring, can achieve uniform lignification and maturation of male kiwifruit branches, unify the dormancy start time and dormancy depth of the entire orchard, promote concentrated bud sprouting, uniform and earlier flowering, and stably advance the peak flowering period of male trees by 5 to 15 days, precisely matching the peak flowering period of the main female trees. This effectively solves the industry problems of misaligned male and female flowering periods and insufficient pollination in warm-winter production areas. At the same time, the targeted cultivation of robust pollinating mother branches can improve flower bud quality and pollen activity, helping to increase fruit set rate and reduce the incidence of deformed fruit. The entire technology is suitable for planting scenarios in southern regions with low winter temperatures and northern regions with warm winters. It is easy to operate, cost-controllable, and highly safe, possessing good value for large-scale promotion and application.

[0073] The above descriptions are merely embodiments of the present invention. Commonly known technical solutions or characteristics are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A method for promoting early cultivation of male kiwifruit plants pollinated by the kiwifruit cultivar, characterized in that, The method includes: S1. Post-flowering pruning and targeted cultivation of pollinating mother branches: Complete the pruning of the entire orchard within 7 days after the flowering period of the pollinated male kiwifruit plants. Shorten all the old flower branches that have finished flowering in the current year, and uniformly retain the branch length of 30cm to 40cm, with 4 to 6 plump and strong buds on each branch; at the same time, remove weak branches, overlapping branches, crossing branches and water sprouts in the inner canopy of the tree. S2. Summer ringing to control excessive growth and promote uniform lignification and maturation of branches: During the window period from late June to early July each year when new shoots stop elongating, choose a sunny and rainless day to lightly ring the base of the current year's healthy pollinating mother branches. The ringing width is 1mm to 2mm, and the cutting depth reaches the surface of the xylem, cutting only the phloem without damaging the xylem vessels. S3. Forced dormancy in winter to unify the dormancy rhythm of the tree: Select a sunny and windless environment, and use a plant leaf drop regulator to spray the entire male kiwi fruit plant evenly until all leaves are evenly moistened and the liquid does not drip. Alternatively, use pruning with leaves to stop the vegetative growth of the tree and force the tree to enter deep dormancy simultaneously. S4. Precise dormancy breaking with cyanamide to achieve concentrated and early budding and flowering: Select windless and rainless weather, determine the application window according to the chilling requirement level of the male kiwifruit pollinating plants, and prepare a cyanamide aqueous solution of the corresponding concentration 30 to 40 days before the local normal natural budding period. Spray the entire pollinating mother branch evenly, focusing on soaking the buds, until the buds are moist but not dripping. Apply budding fertilizer after application, and irrigate in case of drought.

2. The method for promoting early cultivation of male kiwifruit plants according to claim 1, characterized in that: In step S1, the shortening and pruning operation shortens the aging flower branches to within 50cm on each side of the main vine; after removing ineffective branches, the ventilation and light conditions of the tree canopy are improved, the tree nutrients are concentrated to induce the growth of new nutrient branches in summer, and the new nutrient branches are cultivated into pollination mother branches for use in the following year's flowering and pollination.

3. The method for promoting early cultivation of male kiwifruit plants according to claim 1, characterized in that: In step S2, the location of the light girdling treatment is 5cm to 10cm from the base of the healthy pollinating mother branch of the current year to the main vine attachment point; the light girdling treatment blocks the return flow of photosynthetic products to the roots, so that nutrients are concentrated in the upper part of the branch and the buds, accelerating the lignification process of the branch and unifying the maturity of the branches throughout the garden.

4. The method for promoting early cultivation of male kiwifruit plants according to claim 1, characterized in that: In step S3, the plant leaf drop regulator is sprayed in mid-November each year; the plant leaf drop regulator is a mixture of 300 times ethephon and 1000 times S-inducer, or a 3% ethephon aqueous solution. The 300-fold ethephon solution was prepared by diluting 40% ethephon aqueous solution by 300 times, and the 1000-fold S-inducer solution was prepared by diluting 10% S-inducer aqueous solution by 1000 times. After spraying, the leaf drop rate of the plants reached over 90% in early December, and the trees entered dormancy 20 to 30 days earlier.

5. The method for promoting early cultivation of male kiwifruit plants according to claim 1, characterized in that: In step S3, the pruning with leaves is performed in early December each year. During pruning with leaves, the healthy pollinating mother branches of the current year are shortened, leaving a branch length of 30cm to 40cm, with 4 to 6 plump buds on each branch. At the same time, weak branches, overlapping branches, crossing branches and water sprouts in the inner canopy of the tree are removed, and the tree is forced to enter dormancy early by blocking vegetative growth.

6. The method for promoting early cultivation of male kiwifruit plants according to claim 1, characterized in that: In step S4, the cooling requirement level is classified based on the cumulative hours of low temperature at ≤7.2℃: the cumulative hours of low temperature at ≤600 hours are low cooling requirement varieties, and the corresponding application window period is the first half of January; The cumulative low-temperature hours of 600 to 1000 hours are for varieties requiring medium cooling, and the corresponding application window period is mid to late January; The cumulative low-temperature hours ≥1000 hours are for varieties with high cooling requirements, and the corresponding application window period is early to mid-February.

7. The method for promoting early cultivation of male pollinated kiwifruit plants according to claim 6, characterized in that: In step S4, the concentration of the cyanamide aqueous solution is determined according to the cooling requirement level: for low cooling requirement varieties, the cyanamide aqueous solution with a mass fraction of 1% to 1.2% is prepared; for medium cooling requirement varieties, the cyanamide aqueous solution with a mass fraction of 1.2% to 1.5% is prepared; and for high cooling requirement varieties, the cyanamide aqueous solution with a mass fraction of 1.5% to 2.5% is prepared.

8. The method for promoting early cultivation of male kiwifruit plants according to claim 1, characterized in that: In step S4, the irrigation operation maintains the relative water holding capacity of the soil around the tree at 60% to 70%; local over-spraying should be avoided during the application of pesticides.

9. The method for promoting early cultivation of male kiwifruit plants according to claim 1, characterized in that: The method is applicable to areas in the south where low temperatures are scarce in winter, as well as to large-scale kiwifruit production areas in the north where winters are warm.

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