A highly active pollen dissolving agent suitable for drone pollination and its application in walnut pollination

Abstract

The present invention provides a highly active pollen dissolving agent suitable for drone pollination and its application in walnut pollination, belonging to the technical field of walnut pollination. The present invention provides a highly active pollen dissolving agent suitable for drone pollination, which is prepared from the following raw materials in parts by weight: 2 to 2.5 parts agar, 1 to 2 parts xanthan gum, 800 to 1000 parts sucrose, 1 to 5 parts boric acid, 5 to 10 parts calcium nitrate, and 15,000 to 15,500 parts water. Using the highly active pollen dissolving agent, pollen collection and storage method, and drone spray pollination method provided by the present invention, the fruit set rate per plant is increased by 18% to 30%, the empty fruit rate is reduced by 10%, and the average yield per mu is increased by 30%.

Description

Technical Field

[0001] The present invention relates to the technical field of walnut pollination, and in particular to a highly active pollen dissolving agent suitable for drone pollination and application thereof in walnut pollination. Background Art

[0002] Walnut (Juglans) species are world-renowned economic forest species. Yunnan Province, one of the native habitats of walnuts, is China's primary walnut-producing region, accounting for approximately two-thirds of the country's total walnut planting area and production. Walnuts have become a pillar of Yunnan's forestry industry, with walnut plantings totaling 43 million mu (approximately 1.6 million hectares) to date.

[0003] Walnut is a dioecious tree species. The pollinating period of female flowers often differs from the pollination period of male flowers, often resulting in male and female flowers maturing differently. This often leads to a short or absent interfloral period between male and female flowers, resulting in poor pollination and reduced quality in walnut orchards. Walnut has a long history of cultivation in my country. Yunnan Province is a major walnut cultivation province, ranking first in the country in terms of planted area, yield, and output value. However, its yield per unit area is relatively low, primarily due to the province's geographical environment and the influence of walnut varieties. The main walnut variety cultivated in Yunnan is the deep-striped walnut (J. sigillata Dode), also known as the late-bearing walnut or Yunnan walnut, which is clearly distinguishable from the common walnut (J. regia L.) (northern walnut). Deep-grained walnuts exhibit vigorous early vegetative growth, late fruiting, and tall, large trees. Most are male-first, with male and female flowers blooming at different times, with a gap of 10-15 days between them. This results in poor pollination and low fruit set in Yunnan walnuts, severely impacting yield and quality. This is especially true with the emergence of large-scale pure walnut forests and single-variety cultivation, which has made pollination tree configuration increasingly difficult and the pollination environment even more challenging. Consequently, artificial pollination has become essential in production.

[0004] With the development of modern technology and the need to improve the quality and efficiency of the walnut industry, artificial pollination is one of the important measures to increase walnut yield and quality in the future. However, due to the tall size of Yunnan walnut trees, artificial pollination is difficult, risky, and expensive, making it difficult to pollinate. Summary of the Invention

[0005] The purpose of the present invention is to provide a highly active pollen dissolving agent suitable for drone pollination, a preparation method thereof, and use thereof in preserving the activity of walnut pollen, so as to solve the problem of difficult pollination of Yunnan walnuts.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0007] The invention provides a highly active pollen dissolving agent suitable for drone pollination. The highly active pollen dissolving agent is prepared from the following raw materials in parts by weight: 2 to 2.5 parts of agar, 1 to 2 parts of xanthan gum, 800 to 1000 parts of sucrose, 1 to 5 parts of boric acid, 5 to 10 parts of calcium nitrate, and 15,000 to 15,500 parts of water.

[0008] The present invention also provides a method for preparing the highly active pollen dissolving agent, comprising the following steps:

[0009] (1) agar is mixed and dissolved with water to obtain an agar solution;

[0010] (2) mixing the agar solution with xanthan gum and sucrose to obtain a sugar solution;

[0011] (3) The sugar solution is mixed with boric acid and calcium nitrate to obtain a highly active pollen dissolving agent.

[0012] Preferably, the temperature of the water is 40-60°C.

[0013] The present invention also provides an application of the highly active pollen dissolving agent in improving the activity of walnut pollen during drone pollination.

[0014] Preferably, the mass volume ratio of the walnut pollen to the highly active pollen dissolving agent is 50-60 g:40-50 L.

[0015] Preferably, when using drones for pollination, the droplet size is 130 to 200 μm, the spray flow rate is <5 kg / min, and the flight or hovering height is <3 meters from the top of the tree canopy.

[0016] The present invention also provides a method for collecting walnut pollen for use, comprising the following steps:

[0017] (1) Collect walnut male inflorescences and place them in a cool and dry place to dry;

[0018] (2) Collect the dried walnut male inflorescences, sieve them, bottle them, fill the gap between the bottle cap and the pollen with dry sucrose powder above the pollen, seal and refrigerate.

[0019] Preferably, the timing for collecting the walnut male inflorescence is when the walnut male inflorescence is elongated and the pollen sac appears yellow and swollen.

[0020] Preferably, during the drying process, the walnut male inflorescence is placed on a piece of sulfuric acid paper and spread out to dry, wherein the thickness of the spread out piece is less than 1 to 1.5 cm; and the drying time is 24 to 36 hours.

[0021] Preferably, the sieving is carried out sequentially through a 0.100-0110 mm sieve and a 0.070-0.080 mm sieve.

[0022] The highly active pollen suspension suitable for drone pollination provided by this invention solves the problems of pollen settling and uneven dispersion in water, preserves pollen vitality, fully dissolves pollen, and is less likely to clog drone nozzles, facilitating efficient and convenient spraying. This invention also utilizes drone pollination to address the operational difficulties of manual pollination and saves labor.

[0023] The highly active pollen dissolving agent, pollen collection and storage method, and spray pollination method provided by the present invention can increase the fruit setting rate per plant by 18% to 30%, reduce the empty fruit rate by 10%, and increase the average yield per mu by 30%. Therefore, the present invention can be applied to late-bearing and early-bearing walnuts to increase the fruit setting rate, improve quality, and increase yield. DETAILED DESCRIPTION

[0024] The invention provides a highly active pollen dissolving agent suitable for drone pollination. The highly active pollen dissolving agent is prepared from the following raw materials in parts by weight: 2 to 2.5 parts of agar, 1 to 2 parts of xanthan gum, 800 to 1000 parts of sucrose, 1 to 5 parts of boric acid, 5 to 10 parts of calcium nitrate, and 15,000 to 15,500 parts of water.

[0025] In the present invention, the highly active pollen dissolving agent suitable for drone pollination is preferably prepared from the following raw materials in parts by weight: 2 to 2.5 parts of agar, preferably 2.25 parts; 1 to 2 parts of xanthan gum, preferably 1.5 parts; 800 to 1000 parts of sucrose, preferably 900 parts; 1 to 5 parts of boric acid, preferably 3 parts; 5 to 10 parts of calcium nitrate, preferably 7.5 parts; and 15,000 to 15,500 parts of water, preferably 15,200 parts.

[0026] The present invention also provides a method for preparing the highly active pollen dissolving agent, comprising the following steps:

[0027] (1) agar is mixed and dissolved with water to obtain an agar solution;

[0028] (2) mixing the agar solution with xanthan gum and sucrose to obtain a sugar solution;

[0029] (3) The sugar solution is mixed with boric acid and calcium nitrate to obtain a highly active pollen dissolving agent.

[0030] In the present invention, when the agar is mixed and dissolved with water, the agar is first added to 200 parts of water, heated and boiled to dissolve, and then poured into the remaining water to obtain an agar solution.

[0031] In the present invention, the temperature of the water is 40-60°C, preferably 50°C.

[0032] In the present invention, xanthan gum and sucrose are first mixed evenly and then added into the agar solution.

[0033] The present invention also provides an application of the highly active pollen dissolving agent in improving the activity of walnut pollen during drone pollination.

[0034] In the present invention, the mass volume ratio of the walnut pollen to the highly active pollen dissolving agent is 50-60g:40-50L, preferably 55g:45L.

[0035] In the present invention, the walnut pollen and the high-activity pollen dissolving agent are prepared and used immediately.

[0036] In the present invention, the walnut pollen and the highly active pollen dissolving agent are preferably pollinated by spraying with an unmanned aerial vehicle.

[0037] In the present invention, the UAV is preferably a medium to large multi-rotor UAV with a total weight of 50 to 80 kg.

[0038] In the present invention, the amount of spraying pollination is preferably 45 to 55 L / mu, more preferably 50 L / mu.

[0039] In the present invention, the spraying requirements are: droplet particle size of 130 to 200 μm, spray flow rate <5 kg / min, and flight or hovering height <3 meters from the top of the tree canopy.

[0040] In the present invention, the timing of spraying pollination is when more than 30% of the walnut female flower stigmas appear in the V-shaped stage and the eight-shaped stage.

[0041] In the present invention, the pollination is performed 2 to 3 times during the flowering period, preferably 3 times; the interval between each pollination is preferably 3 to 5 days, more preferably 4 times.

[0042] In the present invention, each time the pollination is sprayed, the working area is sprayed 1 to 2 times, with the first time being at a flying speed of 1 to 2 meters per second; and the second time being at a flying speed of 2 to 3 meters per second.

[0043] In the present invention, the weather requirements for pollination are: avoid rainy, high temperature, dry and hot weather, strong winds, preferably cloudy or sunny days; wind speed < level 3; humidity > 35%, horizontal visibility > 2km.

[0044] The present invention also provides a method for collecting walnut pollen for use, comprising the following steps:

[0045] (1) Collect walnut male inflorescences and place them in a cool, dry place to dry;

[0046] (2) Collect the dried walnut male inflorescences, sieve them, bottle them, fill the gap between the bottle cap and the pollen with dry sucrose powder above the pollen, seal and refrigerate.

[0047] In the present invention, the timing for collecting the walnut male inflorescence is when the walnut male inflorescence is elongated and the pollen sac appears yellow and swollen.

[0048] In the present invention, when collecting the walnut male flower inflorescence, it is preferred to collect the entire inflorescence.

[0049] In the present invention, during the air-drying, the walnut male inflorescence is placed on a sulphate paper and spread out to dry, wherein the thickness of the spread out is less than 1 to 1.5 cm; and the air-drying time is 24 to 36 hours, preferably 30 hours.

[0050] In the present invention, the drying is carried out in a spacious room without wind and in the shade.

[0051] In the present invention, the dried pollen sacs will naturally crack and release pollen.

[0052] In the present invention, the pollen sacs are naturally cracked to release pollen and then sieved.

[0053] In the present invention, the sieving is sequentially through a 0.100-0110 mm sieve and a 0.070-0.080 mm sieve, preferably sequentially through a 0.106 mm and a 0.075 mm fine sieve.

[0054] In the present invention, the sieved pollen is placed in a brown glass bottle with a cover, and the space between the bottle cover and the pollen is filled with dry sucrose powder above the pollen.

[0055] In the present invention, the sealed refrigeration is preferably wrapped in a plastic sealed bag and stored in a -18°C freezer.

[0056] The above-mentioned pollen collection and preservation method effectively solves the problem of maintaining pollen vitality after pollen collection.

[0057] The technical solutions provided by the present invention are described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0058] Example 1

[0059] Experimental location and time: In early April 2022 (when the female flowers are at the end of their blooming period), the experiment was carried out at the Yangbi Pao Walnut Planting Base, at an altitude of 1,800m.

[0060] Pollen collection and storage: Walnut pollen is collected when the male inflorescence elongates and the pollen sacs of the florets appear yellow and swollen. The entire inflorescence is harvested and spread out on clean, dry acrylic paper (less than 1-1.5 cm thick). The pollen is then air-dried in a draft-free, spacious room (with doors and windows closed) for 30 hours. The pollen, along with the inflorescences whose pollen sacs have naturally cracked and released pollen, is then collected and passed through 0.106mm and 0.075mm sieves, respectively. The pollen is then placed in brown, covered glass bottles until full. Unfilled bottles are then filled with dry powdered sugar on top of the pollen. Finally, the pollen-containing bottles are wrapped in sealed plastic bags and stored in a -18°C freezer. This pollen collection and storage technique effectively addresses the issue of maintaining pollen viability and storage after collection. This technique is convenient for operation in remote mountainous areas, making it easy to implement and implement.

[0061] Prepare the dissolving agent: Weigh 2.25g of agar powder into 200ml of pure water, heat to boil, and dissolve thoroughly. Pour into 15L of 50°C warm water, stir, and cool to obtain an agar solution. Also, mix 1.5g of xanthan gum and 900g of sucrose thoroughly, then add this to the agar solution to create a sugar solution. Add 3g of boric acid and 7.5g of calcium nitrate to the sugar solution and dissolve thoroughly. Mix thoroughly to obtain a highly active pollen dissolving agent. This dissolving agent preserves and enhances the vitality of walnut pollen.

[0062] Experimental design: Five sample trees were randomly selected from the same plot and numbered (1-5) for full-tree spray pollination. Flower branches were randomly selected for hanging and marking. Five unsprayed trees were selected as controls.

[0063] Weather requirements for pollination: Avoid rain, high temperatures, dry heat, and strong winds. It is best to do it on cloudy or sunny days; wind speed < level 3; humidity > 35%; horizontal visibility > 2km;

[0064] Drone model requirements: Choose a medium or large multi-rotor drone with a total weight of 60kg for spray pollination.

[0065] Spray requirements: droplet size 130-200 μm, spray flow rate <5 kg / min, flight or hovering height <3 meters from the top of the tree canopy;

[0066] Prepare a fresh pollen suspension: Mix 10L of a highly active pollen dissolving agent with 10.15g of pollen to create a highly active pollen suspension. Spray the mixture using an electric sprayer. Preliminary experiments have shown that the pollen suspension prepared with this invention remains stable for over 6 hours, while a pollen suspension prepared with an equal amount of water will stratify after 5 minutes. Furthermore, the pollen suspension provided by this invention can increase pollen germination rates by 24%.

[0067] Operation requirements: Spray the operation area 1 to 2 times, with a flight speed of 1 to 2 meters per second for the first time and 2 to 3 meters per second for the second time.

[0068] Experimental investigation: Before spraying, the opening status of female flowers and the number of flowers before pollination were investigated; at the end of July, the number of fruits set was investigated and the fruit set rate was calculated. The results are shown in Tables 1 and 2.

[0069] Table 1 Comparison of fruit setting rate of each test sample

[0070]

[0071]

[0072] Table 2 Comparison of comprehensive fruit setting rate of test plants and control plants

[0073]

[0074] Note: Letters in the table indicate significant differences at the 0.05 level.

[0075] Example 2

[0076] The test will be conducted in mid-April 2022 (when the female flowers are in full bloom) at the Yangbi Pao Walnut Planting Base, at an altitude of 2,100 m.

[0077] The pollen and solvent are the same as those in Example 1. The weather requirements, drone requirements, and operation requirements for spray pollination are the same as those in Example 1.

[0078] Experimental design: The experiment used drone spraying on a 180-mu walnut forest in a concentrated and contiguous base, with the same area (180 mu) not sprayed as a control.

[0079] Test method: 75 L of high-activity pollen suspension for drones was prepared using the method of the present invention, and sprayed using a T20 four-rotor plant protection drone with a combination of 1.0 and 2.0 nozzles, respectively, and the entire base was flown twice.

[0080] Experimental Survey: In September, five trees were randomly selected from the sprayed and unsprayed plots, and yields were measured according to economic forest yield measurement standards. The yields were statistically analyzed. The results are shown in Table 3.

[0081] Table 3 Comparison of Yangbi walnut production

[0082]

[0083]

[0084] As shown in the above examples, the use of the highly active pollen dissolving agent, pollen collection and storage method, and spray pollination method provided by the present invention can increase the fruit set rate per plant by 18% to 30%, reduce the empty fruit rate by 10%, and increase the average yield per mu by 30%. Therefore, the application of the present invention to late-bearing and early-bearing walnuts can increase the fruit set rate, improve quality, and increase yield.

[0085] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. Application of a highly active pollen dissolving agent in improving the activity of walnut pollen during drone pollination, characterized in that: The highly active pollen dissolving agent is prepared from the following raw materials in parts by weight: 2-2.5 parts of agar, 1-2 parts of xanthan gum, 800-1000 parts of sucrose, 1-5 parts of boric acid, 5-10 parts of calcium nitrate, and 15000-15500 parts of water; The mass volume ratio of the walnut pollen to the highly active pollen dissolving agent is 50-60 g: 40-50 L; When using drones for pollination, the droplet size should be 130-200 μm, the spray flow rate should be less than 5 kg / min, and the flight or hovering height should be less than 3 meters from the top of the tree canopy. The method for collecting walnut pollen comprises the following steps: (1) Collect walnut male inflorescences and place them in a cool and dry place to dry; (2) Collect the dried walnut male inflorescences, sieve them, bottle them, fill the gap between the bottle cap and the pollen with dry sucrose powder, seal and refrigerate; The sieving is carried out sequentially through a 0.100-0.110 mm sieve and a 0.070-0.080 mm sieve.

2. The use according to claim 1, characterized in that The highly active pollen dissolving agent is prepared from the following raw materials in parts by weight: 2.25 parts of agar, 1.5 parts of xanthan gum, 900 parts of sucrose, 3 parts of boric acid, 7.5 parts of calcium nitrate, and 5200 parts of water.

3. The use according to claim 1 or 2, characterized in that The preparation method of the highly active pollen dissolving agent comprises the following steps: (1) Agar is mixed and dissolved with water to obtain an agar solution; (2) Mixing the agar solution with xanthan gum and sucrose to obtain a sugar solution; (3) The sugar solution is mixed with boric acid and calcium nitrate to obtain a highly active pollen dissolving agent.

4. The use according to claim 3, characterized in that The temperature of the water is 40-60°C.

5. The use according to claim 1, characterized in that The timing for collecting the walnut male inflorescence is when the walnut male inflorescence is elongated and the pollen sac appears yellow and swollen.

6. The use according to claim 1 or 5, characterized in that During the drying process, the walnut male inflorescence is placed on sulfuric acid paper and spread out to dry, wherein the thickness of the spread out is less than 1-1.5 cm; and the drying time is 24-36 hours.

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