Method for effectively improving receptivity of macadimia nut styles

Abstract

The method comprises the following steps: preparing a liquid pollination agent: weighing 0.1%-0.5% of white sugar, 0.01%-0.05% of urea, 0.01%-0.05% of boric acid and the balance of deionized water according to the mass volume percent, then placing in an environment of 20-25 DEG C, sequentially adding the white sugar, the urea and the boric acid into the deionized water, and stirring until the white sugar, the urea and the boric acid are completely dissolved, so as to obtain the liquid pollination agent; finally, supplementing deionized water to a constant volume, uniformly stirring, and then adjusting the pH value to 6.0-6.5; in the full-bloom stage of the macadamia nuts, the liquid pollination agent is evenly sprayed to blooming inflorescence in an electrostatic spraying mode, and the spraying amount is 90-110 liters per mu; the spraying time is 8: 30-10: 30 a.m. every day, the treatment is continuously carried out twice, and the period interval is 7-10 days. By constructing a'white sugar-urea-boric acid 'non-hormone synergistic system, the technical problems of short pollination period, low pollen germination rate and insufficient fruit setting rate of macadamia nut styles are solved, and high and stable yield of macadamia nuts is realized.

Description

Technical Field

[0001] This invention relates to the field of agricultural and forestry economic crop cultivation technology, and in particular to a method for effectively improving the receptivity of macadamia nut styles. Background Technology

[0002] The natural fruit set rate of macadamia nuts is generally less than 0.5%, mainly due to the short pollination period of the style (usually only 2-3 days), low pollen germination rate (5.22%-22.66%), slow pollen tube elongation, and insufficient activity of stigma secretions. Current technologies mostly rely on artificial pollination, bee pollination, or hormone-based (such as 6-BA) assistance, which are costly, complicated, and easily affected by environmental factors.

[0003] Although studies have confirmed that boric acid can promote pollen tube elongation (effective at a concentration of 0.03%–0.05%) and sugar can provide energy for pollen (0.3%–0.5% is the commonly used range), the direct application of urea as a nitrogen source in the regulation of receptivity of macadamia nut style has not yet been reported.

[0004] In crops such as pear and rapeseed, urea (0.5%–1%) is used for foliar spraying during flowering to supplement nitrogen and enhance metabolism. However, its synergistic effect with sucrose and boric acid has not been systematically studied in nut crops. This invention is the first to construct a non-hormone synergistic system of "sugar-urea-boric acid," breaking through the traditional path that relies on hormones or thickeners, and achieving low-cost, residue-free, and highly efficient pollination enhancement. Summary of the Invention

[0005] The purpose of this invention is to provide an effective method to improve the receptivity of macadamia nut styles. By constructing a non-hormonal synergistic system of "sugar-urea-boric acid", the invention solves the technical problems of short receptivity period of macadamia nut styles, low pollen germination rate, and insufficient fruit set rate, thereby achieving high and stable yields of macadamia nuts.

[0006] The above-mentioned technical objective of the present invention is achieved through the following technical solution: A method for effectively improving the receptivity of macadamia nut styles includes the following steps: S1. Preparation of liquid pollination agent: Weigh out 0.1%–0.5% white sugar, 0.01%–0.05% urea, and 0.01%–0.05% boric acid by weight and volume percentage, with the remainder being deionized water. Then place the mixture in an environment of 20-25℃. Add white sugar, urea, and boric acid to the deionized water in sequence and stir until completely dissolved. Finally, add deionized water to the final volume and stir evenly. Then adjust the pH value to 6.0–6.5. S2. Spraying operation: During the peak flowering period of macadamia nuts, use electrostatic spraying to evenly spray the liquid pollinator onto the open inflorescences, with a spraying amount of 90-110 liters per acre; S3. Spraying cycle: Spraying time is 8:30-10:30 am every day, for 2 consecutive treatments, with an interval of 7-10 days between treatments.

[0007] Furthermore: in S1, the white sugar is food-grade white granulated sugar with a purity ≥99.5% and a particle size of 80-100 mesh; the urea is analytical grade with a biuret content ≤0.5% and a nitrogen content ≥46.3%, and is uniformly crystallized without lumps; the boric acid is analytical grade with a purity ≥99.5% and a water content ≤0.5%, and is a white crystalline powder without impurities; the deionized water has a conductivity ≤10μS / cm.

[0008] Furthermore: In S1, the liquid pollinator is filtered through a 200-mesh filter before use, and the turbidity of the liquid pollinator is ≤5 NTU.

[0009] Furthermore: In S1, the stirring speed for dissolving is 300–500 r / min.

[0010] Further: In S2, when spraying, the nozzle should be 15-20cm away from the inflorescence to evenly cover the inflorescence with a fine mist. Avoid rainfall or artificial irrigation within 24 hours after spraying.

[0011] Furthermore: In S2, the peak flowering period is when approximately 50% of the macadamia tree florets are open.

[0012] Furthermore, in S2, the electrostatic sprayer operates at a pressure of 0.3–0.5 MPa and has a droplet size of 50–100 μm.

[0013] Further: In S3, stigma receptivity and pollen germination rate were tested 24 hours and 48 hours after the second spray. Stigma receptivity was determined using the benzidine-hydrogen peroxide method, and the amount of bubble generated was counted. Pollen germination rate was determined using an in vitro culture method, and the percentage of germinating pollen was observed and counted under a microscope.

[0014] In summary, the present invention has the following beneficial effects: Firstly, this invention solves the technical problems of short pollen germination rate and insufficient fruit set rate of macadamia nuts by constructing a non-hormone synergistic system of "white sugar-urea-boric acid", thereby achieving high and stable yield of macadamia nuts. Secondly, the formula of this invention does not contain harmful ingredients such as hormones and thickeners. The raw materials are all common agricultural inputs that are easily degradable and leave no residue. They will not have a negative impact on plants, fruits, or the ecological environment, and meet the requirements of green agricultural development. Thirdly, the raw materials of this invention are readily available and have low procurement costs. The solution preparation process is simple, and the spraying method can be achieved using a conventional electrostatic sprayer. No special equipment or professional technicians are required, which facilitates large-scale promotion and application in orchards and significantly reduces the manpower and material costs in the pollination process. Fourth, this invention has good adaptability to different varieties of macadamia nuts and different planting altitudes, providing key technical support for high and stable yields of macadamia nuts and helping to promote the large-scale and standardized development of the industry. Attached Figure Description

[0015] Figure 1 This is an operation flowchart of the present invention; Figure 2 It is a table showing the percentage content and function of each raw material component in the invention. Detailed Implementation

[0016] The present invention will be further described in detail below with reference to the accompanying drawings.

[0017] In the description of this invention, it should be understood that the terms "upper", "lower", "left", "right", "front", "rear", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0018] Furthermore, terms such as "horizontal" and "vertical" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0019] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, a direct connection, or an indirect connection through an intermediate medium; or they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0020] Setting up experiments Experimental materials: The macadamia nut tree variety used was "Guire No. 1", with a tree age of 5 years and uniform growth, planted at the macadamia nut experimental base in Jinghong City, Xishuangbanna Prefecture, Yunnan Province (altitude 600 m); food-grade white sugar (purity 99.8%, particle size 80-100 mesh), analytical grade urea (biuret content ≤0.5%, nitrogen content ≥46.3%), analytical grade boric acid (purity ≥99.5%, moisture content ≤0.5%); deionized water (conductivity ≤10μS / cm).

[0021] Experimental equipment: electrostatic sprayer (working pressure 0.3–0.5 MPa), pH meter (accuracy 0.01), electronic balance (accuracy 0.01g), 200-mesh filter, microscope (magnification 40×), benzidine-hydrogen peroxide reagent kit.

[0022] Reference Figure 1-2 Example 1: A method for effectively improving the receptivity of macadamia nut styles, comprising the following steps: S1. Preparation of liquid pollination agent: Weigh 0.1% white sugar, 0.01% urea, 0.01% boric acid, and 40L deionized water according to the mass-volume percentage. Then, add the white sugar to the deionized water at 20-25℃ and stir at 300-500 rpm for 5-10 minutes until completely dissolved. Then add the urea and continue stirring for 3-5 minutes until the solution is clear. Finally, add the boric acid and stir for 5-8 minutes until completely dissolved. Then adjust the pH value to 6.0 with a pH meter, and finally bring the volume to 50L. Next, filter the liquid pollination agent through a 200-mesh filter to remove any possible trace impurities or undissolved particles, ensuring that the turbidity of the solution is ≤5NTU, and then set it aside for later use. The white sugar is 50g of food-grade white granulated sugar, with a purity of ≥99.5% and a particle size of 80-100 mesh. It is easy to dissolve quickly, avoids residue and clumping, and has no off-odor or mold. The urea is 5g of analytical grade, with a biuret content ≤0.5% to avoid biuret toxicity to pollen and stigma, a nitrogen content ≥46.3% to ensure nitrogen supply efficiency, and uniform crystallization without lumps; Boric acid is 5g of analytical grade, with a purity ≥99.5% and a water content ≤0.5% to prevent moisture from affecting the accuracy of the proportions. It is a white crystalline powder free of impurities. Deionized water has a conductivity of ≤10μS / cm and is free from microbial contamination; S2. Spraying Operation: During the peak flowering period of macadamia trees, when about 50% of the small flowers of the macadamia tree are open, use electrostatic spraying to evenly spray the liquid pollinator onto the open inflorescences. The spraying amount is 90 liters per acre, and the working pressure of the electrostatic sprayer is controlled at 0.3MPa, and the droplet size is 50μm. The fine mist evenly covers the inflorescences to avoid pollen loss due to excessively large droplets. When spraying, keep the nozzle 15cm away from the inflorescence and spray in a "top to bottom, even sweeping spray" manner to ensure that the stigma and anthers of each inflorescence can come into contact with the solution, without omissions or double spraying. Avoid rainfall or artificial irrigation within 24 hours after spraying. S3. Spraying cycle: Spraying time is 8:30-9:30 am daily, with two consecutive treatments and a 7-day interval between them. Stigma receptivity and pollen germination rate are tested 24 hours and 48 hours after the second spray. Stigma receptivity is determined by benzidine-hydrogen peroxide method, and the amount of bubble production is counted. Pollen germination rate is determined by in vitro culture method, and the proportion of germinating pollen is observed and counted under a microscope.

[0023] Example 2, a method for effectively improving the receptivity of macadamia nut styles, comprising the following steps: S1. Preparation of liquid pollination agent: Weigh 0.3% white sugar, 0.03% urea, 0.03% boric acid, and 40L deionized water according to the mass-volume percentage. Then, add the white sugar to the deionized water at 20-25℃ and stir at 300-500r / min for 5-10 minutes until completely dissolved. Then add the urea and continue stirring for 3-5 minutes until the solution is clear. Finally, add the boric acid and stir for 5-8 minutes until completely dissolved. Then adjust the pH value to 6.3 using a pH meter, and finally bring the volume to 50L. Next, filter the liquid pollination agent through a 200-mesh filter to remove any possible trace impurities or undissolved particles, ensuring that the turbidity of the solution is ≤5NTU, and then set it aside for later use. The white sugar is 150g of food-grade white granulated sugar, with a purity of ≥99.5% and a particle size of 80-100 mesh. It is easy to dissolve quickly, avoids residue and clumping, and has no off-odor or mold. The urea is 15g of analytical grade, with a biuret content ≤0.5% to avoid biuret toxicity to pollen and stigma, a nitrogen content ≥46.3% to ensure nitrogen supply efficiency, and uniform crystallization without lumps; Boric acid is 15g of analytical grade, with a purity ≥99.5% and a water content ≤0.5% to prevent moisture from affecting the accuracy of the proportions. It is a white crystalline powder free of impurities. Deionized water has a conductivity of ≤10μS / cm and is free from microbial contamination; S2. Spraying Operation: During the peak flowering period of macadamia trees, when about 50% of the small flowers of the macadamia tree are open, use electrostatic spraying to evenly spray the liquid pollinator onto the open inflorescences. The spraying amount is 100 liters per acre, and the working pressure of the electrostatic sprayer is controlled at 0.4MPa, and the droplet size is 80μm. The fine mist evenly covers the inflorescences to avoid pollen loss due to excessively large droplets. When spraying, keep the nozzle 18cm away from the inflorescence and spray in a "top to bottom, even sweeping spray" manner to ensure that the stigma and anthers of each inflorescence can come into contact with the solution, without omissions or double spraying. Avoid rainfall or artificial irrigation within 24 hours after spraying. S3. Spraying cycle: Spraying time is 9:00-10:00 AM daily, with two consecutive treatments and a 7-day interval between them. Stigma receptivity and pollen germination rate are tested 24 hours and 48 hours after the second spray. Stigma receptivity is determined using the benzidine-hydrogen peroxide method, and the amount of air bubbles produced is counted. Pollen germination rate is determined using the in vitro culture method, and the percentage of germinating pollen is observed and counted under a microscope.

[0024] Example 3, a method for effectively improving the receptivity of macadamia nut styles, comprising the following steps: S1. Preparation of liquid pollination agent: Weigh 0.5% white sugar, 0.015% urea, 0.05% boric acid, and 40L deionized water by weight-volume percentage. Then, add the white sugar to the deionized water at 20-25℃ and stir at 300-500 rpm for 5-10 minutes until completely dissolved. Next, add the urea and continue stirring for 3-5 minutes until the solution is clear. Finally, add the boric acid and stir for 5-8 minutes until completely dissolved. Then adjust the pH value to 6.5 with a pH meter, and finally bring the volume to 50L. Next, filter the liquid pollination agent through a 200-mesh filter to remove any possible trace impurities or undissolved particles, ensuring that the turbidity of the solution is ≤5NTU, and then set it aside for later use. The white sugar is 250g of food-grade white granulated sugar, with a purity of ≥99.5% and a particle size of 80-100 mesh. It is easy to dissolve quickly, avoids residue and clumping, and has no off-odor or mold. The urea is 25g of analytical grade, with a biuret content ≤0.5% to avoid biuret toxicity to pollen and stigma, a nitrogen content ≥46.3% to ensure nitrogen supply efficiency, and uniform crystallization without lumps; Boric acid is 25g of analytical grade, with a purity ≥99.5% and a water content ≤0.5% to prevent moisture from affecting the accuracy of the proportions. It is a white crystalline powder free of impurities. Deionized water has a conductivity of ≤10μS / cm and is free from microbial contamination; S2. Spraying Operation: During the peak flowering period of macadamia trees, when about 50% of the small flowers of the macadamia tree are open, use electrostatic spraying to evenly spray the liquid pollinator onto the open inflorescences. The spraying amount is 110 liters per acre, and the working pressure of the electrostatic sprayer is controlled at 0.5MPa, with a droplet size of 100μm, so as to evenly cover the inflorescences with a fine mist and avoid pollen loss due to excessively large droplets. When spraying, keep the nozzle 20cm away from the inflorescence and spray in a "top to bottom, even sweeping spray" manner to ensure that the stigma and anthers of each inflorescence can come into contact with the solution, without omissions or double spraying. Avoid rainfall or artificial irrigation within 24 hours after spraying. S3. Spraying cycle: Spraying time is 10:00-10:30 am daily, with two consecutive treatments and a 7-day interval between them. Stigma receptivity and pollen germination rate are tested 24 hours and 48 hours after the second spray. Stigma receptivity is determined by benzidine-hydrogen peroxide method, and the amount of bubble production is counted. Pollen germination rate is determined by in vitro culture method, and the proportion of germinating pollen is observed and counted under a microscope.

[0025] Set up a control experiment Blank control group: sprayed with an equal amount of deionized water, and other operations (spraying time, number of times, method, etc.) were the same as in Example 1.

[0026] The binary control group consisted of 0.3% white sugar and 0.03% boric acid in the liquid pollinator, which did not contain urea. Other preparation and operating conditions were the same as in Example 2.

[0027] Hormone control group: Sprayed with 0.001% 6-BA solution, with other procedures the same as in Example 1.

[0028] Experimental Results and Analysis The stigma receptivity, pollen germination rate, and fruit set rate of each embodiment were significantly higher than those of the blank control group. Among them, Example 2 showed the best overall effect, with stigma receptivity reaching 2.8 times that of the blank control group, pollen germination rate as high as 56.7%, and fruit set rate increased to 2.32%, which is significantly improved compared with the natural fruit set rate (below 0.5%). This proves that the "sugar-urea-boric acid" ternary synergistic system of the present invention has a good pollination enhancement effect.

[0029] All indicators of the binary control group were lower than those of Example 2, indicating that the addition of urea can significantly enhance the synergistic effect, confirming the key role of urea as a fast-acting nitrogen source in promoting pollen cell protein synthesis and enzyme activity and enhancing germination dynamics, and also verifying the synergistic advantages of the ternary system.

[0030] Although the effect of the hormone control group was better than that of Example 1, it was lower than that of Example 2 and Example 3, and there was a risk of hormone residue. In contrast, the formula of the present invention is hormone-free and residue-free, which is more in line with the needs of green agricultural development. At the same time, the operating cost is lower and it is more suitable for large-scale application.

[0031] This specific embodiment is merely an explanation of the present invention and is not intended to limit the invention. After reading this specification, those skilled in the art can make inventive modifications to this embodiment as needed, but as long as they are within the scope of the claims of the present invention, they are protected by patent law.

Claims

1. A method of increasing the pistil receptivity of a Macadamia nut flower, the method comprising, The method comprises the following steps: S1, preparing a liquid pollination agent: taking white sugar 0.1%-0.5%, urea 0.01%-0.05%, boric acid 0.01%-0.05% by mass fraction, and the rest is deionized water, then placing in an environment of 20-25℃, adding white sugar, urea and boric acid in deionized water in turn and stirring until completely dissolved, finally adding deionized water to the constant volume and stirring uniformly, then adjusting the pH value to 6.0-6.5; S2, spraying operation: during the flowering period of macadamia, the liquid pollination agent is uniformly sprayed on the open inflorescence by electrostatic spraying, and the spraying amount is 90-110 liters per mu; S3, spraying cycle: the spraying time is 8:30-10:30 in the morning, and the continuous treatment is 2 times, and the interval is 7-10 days.

2. A method of increasing the receptivity of the style of a macadamia nut according to claim 1, characterised in that: In S1, the white sugar is food grade white granulated sugar with purity ≥99.5% and particle size 80-100 mesh; the urea is analytical pure with biuret content ≤0.5% and nitrogen content ≥46.3%, and the crystal is uniform without caking; the boric acid is analytical pure with purity ≥99.5% and water content ≤0.5%, and the white crystalline powder is free of impurities; the conductivity of deionized water is ≤10 μS / cm.

3. A method of increasing the receptivity of the style of a macadamia nut according to claim 1, characterised in that: In S1, the liquid pollination agent is filtered through a 200 mesh filter for standby, and the turbidity of the liquid pollination agent is ≤5 NTU.

4. A method of increasing the receptivity of the style of a macadamia nut according to claim 1, characterised in that: In S1, the stirring speed for dissolving is 300-500 r / min.

5. A method of increasing the receptivity of the style of a macadamia nut according to claim 1 characterised in that: In S2, the nozzle distance from the inflorescence is 15-20 cm when spraying, and the inflorescence is uniformly covered with fine mist, and rain or artificial irrigation is avoided within 24 hours after spraying.

6. A method of increasing the receptivity of the style of a macadamia nut according to claim 1 characterised in that: In S2, the flowering period is when about 50% of the small flowers of macadamia nut trees are open.

7. A method of increasing the receptivity of the style of a macadamia nut according to claim 1 characterised in that: In S2, the working pressure of the electrostatic sprayer is 0.3-0.5 MPa, and the droplet size is 50-100 μm.

8. A method of increasing the receptivity of the style of a macadamia nut according to claim 1 characterised in that: In S3, the stigma receptivity and pollen germination rate are detected 24 hours and 48 hours after the second spraying, the stigma receptivity is determined by benzidine-hydrogen peroxide method, and the amount of bubble generation is counted; the pollen germination rate is determined by in vitro culture method, and the proportion of germinated pollen is observed and counted under a microscope.

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