A method for thinning fruit in pear trees

Abstract

This invention relates to the field of fruit tree cultivation technology and discloses a method for thinning pear fruit. The invention reveals that applying melatonin to pear trees significantly reduces fruit size without causing any significant adverse effects on the main quality indicators of the pear fruit. The method provided by this invention has a simple formula, low cost, and is easy to operate. It can efficiently and stably remove excess young fruit while ensuring fruit quality, effectively increasing pear yield, and saving labor. It provides an effective and reliable solution to the problem of fruit thinning in pear production.

Description

Technical Field

[0001] This invention relates to the field of fruit tree cultivation technology, specifically to a method for thinning fruit in pear trees. Background Technology

[0002] Fruit thinning is a core step in the cultivation of high-quality and high-yield pear trees. Traditional manual fruit thinning is costly and inefficient, while chemical fruit thinning has poor stability and cannot meet the management needs of modern orchards. Therefore, environmentally friendly and stable fruit thinning materials are the ideal alternative.

[0003] Melatonin (N-acetyl-5-methoxytryptamine), a natural indoleamine compound, has shown potential in regulating growth and development in fruit tree cultivation. Liu et al. (2019) reported that spraying pear trees with 100 μmol / L melatonin increased fruit weight by 47.85%; Liu et al. (2018) reported that melatonin induced parthenocarpy in 'Starkrimson' pear. These studies all indicate that melatonin has a growth-promoting effect on pear trees at conventional concentrations.

[0004] There are currently no reports on melatonin as a fruit thinning agent for pear trees, and it is unclear whether it can achieve fruit thinning by regulating fruit abscission under specific treatment conditions. At the same time, developing a new, efficient, safe, stable, and environmentally friendly method for thinning pear trees has important practical application value. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide an innovative method for thinning pear fruit. The application of melatonin in pear trees focuses on promoting fruit development and improving quality. By selecting melatonin as a thinning agent and applying it according to a specific time sequence, the problems of unstable thinning effect and poor safety in existing technologies are solved, effectively reducing labor costs and ensuring stable fruit quality, making it particularly suitable for large-scale pear orchard management.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention protects the use of melatonin in any of the following:

[0008] (A1) Application in fruit thinning of pear trees;

[0009] (A2) Application in the preparation of pear fruit thinning agents.

[0010] In a specific implementation plan, the melatonin concentration is 120~280 mg / L.

[0011] In a more specific implementation, the melatonin concentration is 200 mg / L.

[0012] In a specific implementation, the formulation also includes agriculturally acceptable adjuvants.

[0013] In a specific implementation plan, the auxiliary agent is 75% ethanol.

[0014] In specific implementation schemes, the formulation also includes other fruit-bearing active substances.

[0015] More specifically, such as calcium formate, benzalkonium chloride, etc.

[0016] Secondly, this invention protects a method for thinning fruit in pear trees, the method comprising the following steps:

[0017] Step 1: During the peak flowering period of pear trees, spray the first application of a melatonin solution of 120~280 mg / L (preferably 200 mg / L).

[0018] Step 2: 10 days after the peak flowering period, spray a second time with a melatonin solution of 120~280 mg / L, preferably 200 mg / L;

[0019] Step 3: 20 days after the peak flowering period, spray a third time with a melatonin solution of 120~280 mg / L, preferably 200 mg / L.

[0020] The peak flowering period for pear trees refers to when about 70% to 80% of the pear tree is in bloom.

[0021] In a specific implementation plan, the 200 mg / L melatonin solution is prepared as follows: Dissolve 200 mg of melatonin in 4 mL of 75% ethanol to form a homogeneous and transparent solution, add water to make up to 1 L, and shake well to obtain the 200 mg / L melatonin working solution.

[0022] In the specific implementation plan, the melatonin solution is prepared according to the principle of being prepared and used immediately, and the drug needs to be protected from light or stored at low temperature.

[0023] In the specific implementation plan, when spraying melatonin solution, it should be done on a sunny, windless day with a temperature of 15-25℃, and the spraying time should be 7:00-9:00 and / or 15:00-17:00.

[0024] In the specific implementation plan, the first spraying mainly targets the leaves and flower organs, the second spraying mainly targets the leaves and young fruits, and the third spraying mainly targets the leaves and young fruits. During spraying, a sprayer is used to evenly spray the fruit tree canopy, with the sprayer nozzle 30 cm away from the tree, and approximately 8 mL sprayed per branch.

[0025] In the specific implementation plan, the pear varieties are 'Cuiguan', 'Cuiyu', 'Fengshui', etc.

[0026] The beneficial effects of this invention are:

[0027] (1) Unique mechanism: This invention is the first to use melatonin for fruit thinning in pear trees, transforming it from a fruit-promoting agent into a fruit-thinning agent.

[0028] (2) The fruit thinning effect of the present invention is significant and the risk of pesticide damage is low: by spraying in stages according to time sequence, it can exert the maximum effect at the most sensitive physiological stage of the fruit tree, significantly reducing the risk of pesticide damage to the tree. After thinning, the remaining fruits develop well, no deformed fruits are seen, the leaves do not have yellowing or other pesticide damage symptoms, the tree recovers quickly, and the whole thinning process is more gentle and controllable.

[0029] (3) Expanding the window of action: Melatonin acts from the full bloom period to 20 days after full bloom, which can broaden the effective application period and provide greater flexibility for agricultural operations.

[0030] (4) Safety: No pesticide damage such as yellowing of leaves or deformed fruit occurs. Attached Figure Description

[0031] Figure 1 Analysis of the effects of different treatments on fruit thinning of 'Cuiguan' varietal;

[0032] Figure 2 Analysis of the effects of different treatments on fruit thinning in 'Cuiyu' varietal variety;

[0033] Figure 3 Analysis of the effects of different treatments on fruit thinning in 'high-water' crops;

[0034] Figure 4 Comparison of fruit thinning effects of 'Cuiguan' ...fruit thinning' before and after C1 treatment;

[0035] Figure 5 Comparison of fruit thinning effects of 'Cuiguan' varietal fruit before and after C2 treatment;

[0036] Figure 6 Comparison of fruit thinning effects of 'Cuiguan' ...fruit thinning' before and after C3 treatment;

[0037] Figure 7 Comparison of fruit thinning effects of 'Cuiguan' varietal fruit before and after the control group treatment;

[0038] Figure 8 Flowchart of the preparation and application time of fruit thinning agent. Detailed Implementation

[0039] The present invention will be described in detail below through embodiments, but is not intended to limit the scope of the invention:

[0040] The present invention will be further described below with reference to embodiments, but this does not constitute any limitation on the present invention. Any limited modifications made within the scope of the claims of the present invention are still within the scope of the claims of the present invention.

[0041] Example 1: Exogenous application of fruit thinning agent to 'Cuiguan' fruit cultivar

[0042] 1. Set up the following 3 treatment methods, with 3 concentration gradients for each treatment:

[0043] Treatment A: Calcium formate was applied in a concentration gradient of A1 (3.3 g / L), A2 (6.6 g / L), and A3 (9.9 g / L).

[0044] Treatment B: Apply benzalkonium chloride at concentration gradients of B1 (300 mg / L), B2 (350 mg / L), and B3 (400 mg / L).

[0045] Treatment C: Melatonin was administered at concentration gradients of C1 (120 mg / L), C2 (200 mg / L), and C3 (280 mg / L).

[0046] Treatment CK: Pure water control.

[0047] 2. The preparation of fruit thinning agents should follow the principle of preparing and using immediately. The agents should be stored away from light or at low temperatures. Three agents were selected: calcium formate, benzoyl permethrin, and melatonin. 3.3g of calcium formate was dissolved in 50mL of water, and the solution was brought to the required volume with water. 100mg of benzoyl permethrin was dissolved in 7.5mL of 75% ethanol to form a homogeneous and transparent solution, and the solution was brought to the required volume with water. 50mg of melatonin was dissolved in 1mL of 75% ethanol to form a homogeneous and transparent solution, and the solution was brought to the required volume with water. A control group was prepared using pure water.

[0048] 3. The experimental site was located at the Nanjing Agricultural University Baima Teaching and Research Base—Nanjing Branch of the National Pear Improvement Center in Lishui District, Nanjing City, Jiangsu Province. The tree variety used in the experiment was 'Cuiguan'. Healthy and uniform pear trees with no history of serious pests and diseases and similar tree shapes were selected for spraying. Each treatment was replicated three times in a randomized block design and was labeled.

[0049] 4. Choose a sunny, windless day with temperatures between 15 and 25°C. The most suitable time for spraying is between 7:00 and 9:00 AM or between 3:00 and 5:00 PM. When the pear trees are in full bloom (approximately 70% to 80% of the tree is in bloom), the first spray should be applied to the leaves and flower organs, and this should be done for 10 days. Ten days after full bloom, the second spray should be applied to the leaves and young fruit, and this should be done for another 10 days. Twenty days after full bloom, the third spray should be applied to the leaves and young fruit. The control group was sprayed with pure water. Use a sprayer to evenly spray the canopy of the fruit trees, with the sprayer nozzle 30 cm away from the tree. The amount sprayed per branch is approximately 8 mL.

[0050] 5. Count the number of flowers or young fruits before spraying for each treatment. After the physiological fruit drop is completed, investigate the number of fruits set for each treatment and calculate the thinning rate.

[0051] 6. During the fruit ripening period, randomly sample several ripe pears from all sides of each treatment and measure relevant indicators of the fruit's internal and external quality, including: single fruit weight, longitudinal and transverse diameters, firmness, soluble solids content, titratable acid, stone cell content, etc.

[0052] Table 1. Effects of different treatments on the removal rate of 'Crown'.

[0053]

[0054] Table 2 Effects of different treatments on the fruit quality of 'Cuiguan' ...

[0055]

[0056] Example 2: Exogenous application of fruit thinning agent to 'Emerald'

[0057] 1. Set up the following 3 treatment methods, with 3 concentration gradients for each treatment:

[0058] Treatment A: Calcium formate was applied in a concentration gradient of A1 (3.3 g / L), A2 (6.6 g / L), and A3 (9.9 g / L).

[0059] Treatment B: Apply benzalkonium chloride at concentration gradients of B1 (300 mg / L), B2 (350 mg / L), and B3 (400 mg / L).

[0060] Treatment C: Melatonin was administered at concentration gradients of C1 (120 mg / L), C2 (200 mg / L), and C3 (280 mg / L).

[0061] Treatment CK: Pure water control.

[0062] 2. The preparation of fruit thinning agents should follow the principle of preparing and using immediately. The agents should be stored away from light or at low temperatures. Three agents were selected: calcium formate, benzoyl permethrin, and melatonin. 3.3g of calcium formate was dissolved in 50mL of water, and the solution was brought to the required volume with water. 100mg of benzoyl permethrin was dissolved in 7.5mL of 75% ethanol to form a homogeneous and transparent solution, and the solution was brought to the required volume with water. 50mg of melatonin was dissolved in 1mL of 75% ethanol to form a homogeneous and transparent solution, and the solution was brought to the required volume with water. A control group was prepared using pure water.

[0063] 3. The experimental site was located at the Nanjing Agricultural University Baima Teaching and Research Base—Nanjing Branch of the National Pear Improvement Center in Lishui District, Nanjing City, Jiangsu Province. The tree variety used in the experiment was 'Cuiyu'. Healthy and uniform pear trees with no history of serious pests and diseases and similar tree shapes were selected for spraying. Each treatment was replicated three times in a randomized block design and was labeled.

[0064] 4. Choose a sunny, windless day with temperatures between 15 and 25°C. The most suitable time for spraying is between 7:00 and 9:00 AM or between 3:00 and 5:00 PM. When the pear trees are in full bloom (approximately 70% to 80% of the tree is in bloom), the first spray should be applied to the leaves and flower organs, and this should be done for 10 days. Ten days after full bloom, the second spray should be applied to the leaves and young fruit, and this should be done for another 10 days. Twenty days after full bloom, the third spray should be applied to the leaves and young fruit. The control group was sprayed with pure water. Use a sprayer to evenly spray the canopy of the fruit trees, with the sprayer nozzle 30 cm away from the tree. The amount sprayed per branch is approximately 8 mL.

[0065] 5. Count the number of flowers or young fruits before spraying for each treatment. After the physiological fruit drop is completed, investigate the number of fruits set for each treatment and calculate the thinning rate.

[0066] 6. During the fruit ripening period, randomly sample several ripe pears from all sides of each treatment and measure relevant indicators of the fruit's internal and external quality, including: single fruit weight, longitudinal and transverse diameters, firmness, soluble solids content, titratable acid, stone cell content, etc.

[0067] Table 3. Effects of different treatments on the removal rate of 'jadeite'

[0068]

[0069] Table 4 Effects of different treatments on the fruit quality of 'Cuiyu' 'Jade' 'fruit'

[0070]

[0071] Example 3: 'Fengshui' exogenous spraying of fruit thinning agent

[0072] 1. Set up the following 3 treatment methods, with 3 concentration gradients for each treatment:

[0073] Treatment A: Calcium formate was applied in a concentration gradient of A1 (3.3 g / L), A2 (6.6 g / L), and A3 (9.9 g / L).

[0074] Treatment B: Apply benzalkonium chloride at concentration gradients of B1 (300 mg / L), B2 (350 mg / L), and B3 (400 mg / L).

[0075] Treatment C: Melatonin was administered at concentration gradients of C1 (120 mg / L), C2 (200 mg / L), and C3 (280 mg / L).

[0076] Treatment CK: Pure water control.

[0077] 2. The preparation of fruit thinning agents should follow the principle of preparing and using immediately. The agents should be stored away from light or at low temperatures. Three agents were selected: calcium formate, benzoyl permethrin, and melatonin. 3.3g of calcium formate was dissolved in 50mL of water, and the solution was brought to the required volume with water. 100mg of benzoyl permethrin was dissolved in 7.5mL of 75% ethanol to form a homogeneous and transparent solution, and the solution was brought to the required volume with water. 50mg of melatonin was dissolved in 1mL of 75% ethanol to form a homogeneous and transparent solution, and the solution was brought to the required volume with water. A control group was prepared using pure water.

[0078] 3. The experimental site was located at the Nanjing Agricultural University Baima Teaching and Research Base—Nanjing Branch of the National Pear Improvement Center in Lishui District, Nanjing City, Jiangsu Province. The tree variety used in the experiment was 'Fengshui'. Healthy and uniform pear trees with no history of serious pests and diseases and similar tree shapes were selected for spraying. Each treatment was replicated three times in a randomized block design and was labeled.

[0079] 4. Choose a sunny, windless day with temperatures between 15 and 25°C. The most suitable time for spraying is between 7:00 and 9:00 AM or between 3:00 and 5:00 PM. When the pear trees are in full bloom (approximately 70% to 80% of the tree is in bloom), the first spray should be applied to the leaves and flower organs, and this should be done for 10 days. Ten days after full bloom, the second spray should be applied to the leaves and young fruit, and this should be done for another 10 days. Twenty days after full bloom, the third spray should be applied to the leaves and young fruit. The control group was sprayed with pure water. Use a sprayer to evenly spray the canopy of the fruit trees, with the sprayer nozzle 30 cm away from the tree. The amount sprayed per branch is approximately 8 mL.

[0080] 5. Count the number of flowers or young fruits before spraying for each treatment. After the physiological fruit drop is completed, investigate the number of fruits set for each treatment and calculate the thinning rate.

[0081] 6. During the fruit ripening period, randomly sample several ripe pears from all sides of each treatment and measure relevant indicators of the fruit's internal and external quality, including: single fruit weight, longitudinal and transverse diameters, firmness, soluble solids content, titratable acid, stone cell content, etc.

[0082] Table 5. Effects of different treatments on the 'high water' dredging rate

[0083]

[0084] Table 6. Effects of different treatments on the fruit quality of 'Fengshui' variety.

[0085]

[0086] In summary, in terms of removal effect, among the nine treatment groups, the C2 medium concentration treatment (200 mg / L melatonin) performed the best, achieving the highest removal rate in all three varieties. Specifically, the removal rate of 'Cuiguan' was 55.87%, 'Cuiyu' was 61.53%, and 'Fengshui' was 56.21%, which was significantly better than the other treatment groups and the control group.

[0087] Regarding concentration selection, too low a concentration (120 mg / L melatonin) results in insufficient melatonin accumulation within the tree, failing to activate abscission signals and leading to a low thinning rate. Conversely, high concentrations of melatonin (280 mg / L melatonin) may cause physiological stress, inhibiting abscission and thus reducing the thinning rate. Therefore, there is an optimal concentration range for melatonin fruit thinning. The 200 mg / L melatonin concentration ratio provided in this invention is the core parameter for achieving efficient thinning with this fruit thinning agent. It can effectively regulate the fruit thinning effect for different pear varieties, demonstrating the wide adaptability and reliability of this formulation.

[0088] The applicant also monitored single-application spraying and found that the short-duration action of the pesticide only produced a momentary physiological stimulus to the flowers and fruits, failing to continuously induce flower and fruit abscission and making it difficult to achieve the desired thinning effect. The thinning rate of each treatment group after a single application was less than 15%. Three applications at different times showed a significant synergistic effect of pesticide efficacy and physiological regulation. Compared with a single application, it can significantly improve the thinning rate, has a milder pesticide effect, and avoids the tree stress and pesticide damage risks caused by a single high-concentration application.

[0089] In terms of fruit quality, all treatment groups treated with the fruit thinning agent of this invention maintained the key commercial quality indicators of mature fruit, such as single fruit weight, firmness, soluble solids content, and stone cell content, within the range of normal high-quality fruit. This proves that while the fruit thinning agent of this invention has an efficient thinning function, the stress on tree physiology and fruit development is within a safe threshold and will not adversely affect the core commercial value of the fruit, thus achieving an organic unity of "quantity control" and "quality preservation".

[0090] Regarding varietal adaptability, this experiment selected three pear varieties—'Cuiguan,' 'Cuiyu,' and 'Fengshui'—within the same ecological region for verification. The results showed that 200 mg / L melatonin exhibited a relatively consistent and significant thinning advantage in all three varieties, and the fruit quality of each variety was not significantly negatively affected. This preliminarily demonstrates that the fruit thinning agent of this invention has a certain degree of universality and stability for different pear varieties in a specific region, reducing the uncertainty of application effects caused by varietal differences and enhancing its potential for widespread application.

[0091] Therefore, the pear fruit thinning method provided by this invention, through optimized component concentration ratios, particularly the spraying of a 200 mg / L melatonin solution, has been proven in multi-variety field trials to achieve efficient and stable fruit thinning results while ensuring the safety and quality of pear fruit. This technical solution has clear effects, high safety, and good varietal adaptability, making it easier for fruit growers to accept and promote. It provides effective key technical support for the intensive and labor-saving cultivation of pear trees and has enormous market application potential.

[0092] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. The application of melatonin in any of the following: (A1) Application in fruit thinning of pear trees; (A2) Application in the preparation of pear fruit thinning agents.

2. The application according to claim 1, characterized in that, The melatonin concentration is 120~280 mg / L.

3. The application according to claim 1, characterized in that, The formulation also includes agriculturally acceptable adjuvants.

4. The application according to claim 3, characterized in that, The additive is 75% ethanol.

5. The application according to claim 1, characterized in that, The formulation also includes other fruit-bearing active substances.

6. A method for thinning fruit in pear trees, characterized in that, The method includes the following steps: Step 1: During the peak flowering period of pear trees, spray with a 120-280 mg / L melatonin solution for the first time; Step 2: 10 days after the peak flowering period, spray a second time with a 120-280 mg / L melatonin solution; Step 3: 20 days after the peak flowering period, spray a third time with a 120-280 mg / L melatonin solution.

7. The fruit thinning method according to claim 6, characterized in that, When spraying melatonin solution, choose a sunny, windless day with a temperature between 15 and 25°C. The spraying time should be between 7:00 and 9:00 and / or between 15:00 and 17:

00.

8. The fruit thinning method according to claim 6, characterized in that, The first spraying mainly targets the leaves and flower organs, the second spraying mainly targets the leaves and young fruits, and the third spraying mainly targets the leaves and young fruits.

9. The fruit thinning method according to claim 8, characterized in that, The spraying solution should evenly cover all leaves, inflorescences and / or young fruits of the tree, with a spraying amount of 8±3 ml per branch.

10. The method according to claim 6, characterized in that, The pear varieties mentioned are 'Cuiguan', 'Cuiyu', or 'Fengshui'.

Images