Soil nematode prevention and control method for millet planting area
By adopting three-layer embedded sustained-release structure, the problem of nematode control in soil in millet planting areas is solved, efficient nematode control and high germination rate are achieved, and the medicinal effect is extended.
Patent Information
- Application Number
- CN202510140163.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-08
- Publication Date
- 2025-04-11
AI Technical Summary
The prior art cannot effectively prevent and control nematodes in the soil in the millet planting area, causing nematodes to continue to spread during the planting process and endanger the plants.
Three-layer embedded sustained-release structure is used to slow the release rate of thyroid elixir, including core-shell, intermediate and surface layers, which slows down the release rate of thyroid elixir and prolongs the drug effect.
The nematode control rate of up to 90% and the germination rate of over 95% were achieved, which far exceeds the effect of existing linear refractories and does not affect the germination of millet seeds.
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Figure CN119790764A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of nematode control, and particularly relates to a method for controlling soil nematodes in a millet planting area. Background Art
[0002] Millet nematode disease is an important seed-borne disease in my country's summer millet production areas. It is common in central and southern Hebei, Shandong, Henan and other places. In severe cases, the yield of plots can be reduced by 50% to 80%, or even a total loss. Due to factors such as the frequent transportation of millet seeds, the difficulty in breeding disease-resistant varieties, and the fact that the main cultivated varieties are susceptible varieties, the nematode disease spread rapidly after it was introduced into the spring millet area in 2017, especially in western Jilin Province, where it was severely affected in some areas.
[0003] Currently, the main method of preventing and controlling millet nematode disease is to use nematicides to suffocate millet seeds and then plant them. Stuffing can kill most of the parasitic nematodes carried on the seeds, but this method cannot pose a threat to the nematodes already existing in the soil of the planting area, resulting in the nematodes spreading along the soil and parasitizing the underground part of the plant during the planting and growth process.
[0004] Although there are nematicides on the market for nematodes in the soil, most of them have a short duration of effectiveness and affect the germination rate of seeds. Summary of the invention
[0005] In order to solve the problems existing in the above-mentioned prior art, the present invention provides a method for controlling soil nematodes in millet planting areas. By adopting a three-layer embedded sustained-release structure, it can promote the germination and growth of millet while controlling nematodes. At the same time, hydrogel is used to slow down the release rate of carbofuran, so that the efficacy of carbofuran is long-lasting.
[0006] The specific technical solution adopted by the present invention is:
[0007] A method for controlling soil nematodes in a millet planting area comprises the following steps:
[0008] S1. preparing nematicidal particles, wherein the nematicidal particles comprise, from the inside to the outside, a seed, a core-shell layer, an intermediate layer, and a surface layer;
[0009] S2, spreading the nematicide granules into the sowing furrow for planting;
[0010] The preparation method of the nematocidal granules comprises the following steps:
[0011] S101, preparing a core-shell layer, dissolving brassinolide in ethanol, dissolving chitosan in acetic acid, and then mixing the two solutions to obtain a mixed solution, spraying the mixed solution on the surface of the seeds to form a film layer, which is the core-shell layer, and drying the core-shell layer in the sun for 2-3 minutes to obtain first particles;
[0012] S102, preparing an intermediate layer, grinding millet ash into powder, and then uniformly wrapping the millet ash powder on the surface of the first particle, and after thorough drying, obtaining a second particle, wherein the film layer formed by the millet ash powder on the surface of the second particle is the intermediate layer;
[0013] S103, preparing a surface layer, dispersing the hydrogel in water, then adding cartap and mixing by ultrasonic dispersion to obtain a gel solution, placing the second particles into the gel solution and dispersing them by ultrasonic dispersion, then taking out the second particles, drying and dispersing them to obtain nematicidal particles, wherein the gel film formed on the surface of the nematicidal particles is the surface layer.
[0014] Furthermore, in step S101, the concentration of brassinolide in the mixed solution is 2-4 g / L, and the concentration of chitosan is 1-2 g / L.
[0015] Furthermore, the particle size of the millet wood ash powder is 50-100 μm.
[0016] Furthermore, the concentration of cartap in the gel solution in step S103 is 0.15-0.3 g / L.
[0017] Furthermore, in step S103, the second particles are placed in the gel solution and ultrasonically dispersed for a period of 10-20 seconds.
[0018] Furthermore, the preparation method of the hydrogel comprises the following steps:
[0019] A. Dissolve sodium alginate in water to form a sodium alginate solution;
[0020] B. Dissolving calcium salt in water to form a calcium salt solution, adding the calcium salt solution to the sodium alginate solution, reacting for 1-2 hours to obtain a cross-linked mixture;
[0021] C. Let the cross-linked mixture stand, take out the jelly, wash and dry it to obtain a hydrogel.
[0022] Furthermore, the concentration of sodium alginate in the sodium alginate solution is 10-20 g / L.
[0023] Furthermore, the calcium salt is any one of calcium chloride, calcium iodide and calcium nitrate, and the concentration of the calcium salt in the calcium salt solution is 0.4-0.6 mol / L.
[0024] Furthermore, in step B, the volume ratio of the sodium alginate solution to the calcium salt solution is 1:0.5-1.
[0025] The beneficial effects of the present invention are:
[0026] 1. The nematode-killing particles of the present invention are used to control millet nematodes, with a nematode control rate of more than 90% and a germination rate of more than 95%. Not only does the nematode control rate far exceed the soil nematicide control effect of existing nematicides, but it also has no adverse effects on millet seeds and promotes seed germination.
[0027] 2. The nematode killing particles of the present invention are of a three-layer embedded sustained-release structure, and the outermost surface layer takes effect first. The cartap therein is a highly effective insecticide, which has a significant toxic effect on soil nematodes. When the surface layer contacts water, it will expand rapidly, and the specific surface area will increase. At the same time, due to the high moisture content in the soil, cartap can be quickly and massively released to the surrounding soil in contact with the nematode killing particles, and the number of nematode populations in the soil will be rapidly reduced at the initial stage of application. With the infiltration and volatilization of water, the hydrogel loses water and shrinks, the specific surface area decreases, and the soil moisture slows down the release speed of cartap, making the drug effect more lasting.
[0028] The middle layer is millet ash, which is rich in various mineral elements. It can not only provide nutrients for the soil, but also regulate the pH value of the soil. When the millet ash powder in the middle layer is gradually released, it can make the soil environment unfavorable for the survival of nematodes and continuously inhibit the growth and reproduction of nematodes. At the same time, the millet ash powder in the middle layer also plays a first-level protective role, separating the cartap from the seeds, avoiding the contact between the cartap and the seeds in the early stage and affecting the germination of the seeds.
[0029] The main components of the core-shell layer are brassinolide and chitosan. Brassinolide is a highly effective plant growth regulator that can stimulate seed growth and enhance the stress resistance of millet. Chitosan has good film-forming properties and biological activity, and forms a biological stimulation layer with brassinolide to promote seed germination. At the same time, the core-shell layer plays a second-level protective role, and the formed film layer separates the carbofuran from the seeds.
[0030] At the same time, due to the protection of the surface layer and the middle layer, the loss of brassinolide and chitosan is reduced, thereby increasing the duration of the core-shell layer promoting seed growth.
[0031] 3. After the first particles in the present invention are prepared, the core-shell layer on the surface is dried for a short time. The chitosan in the core-shell layer is mixed with the powdery millet ash (and fully dried) due to its viscosity to form a solid protective shell with a porous structure. The second particles are put into the gel solution. Under the action of ultrasonic dispersion, the gel diffuses inward along the pores of the protective shell to form a number of inwardly extending burrs. During the seed germination process, after the core-shell layer and the middle layer are broken, the carbidopa in the surface layer is released along the burrs to the seed epidermis in a trace amount. On the premise of having a nematic effect on the seeds, the seeds in the early germination stage are prevented from contacting a large amount of carbidopa to affect the germination rate. The second particles are ultrasonically dispersed in the gel solution for only a dozen seconds to avoid long-term immersion in the gel solution to destroy the structure of the protective shell.
[0032] The presence of millet wood ash will dilute and block the transported carbofuran, further avoiding the adverse effects of higher concentrations of carbofuran on seed germination.
[0033] In addition, because the surface layer is a hydrogel, it has good tension in the moist soil after sowing. It can continuously wrap the swollen millet for a certain period of time after the millet germinates, thereby prolonging the duration of drug action. Even after the millet germinates, it can protect the millet roots for a certain period of time, thereby further improving the effect of nematode control. BRIEF DESCRIPTION OF THE DRAWINGS
[0034] Figure 1 Field photo 1 showing the effect of controlling millet nematode disease;
[0035] Figure 2 Field photo 2 showing the effect of controlling millet nematode disease. DETAILED DESCRIPTION
[0036] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments:
[0037] Example 1
[0038] Preparation of hydrogel:
[0039] A. Dissolve sodium alginate in water to form a sodium alginate solution with a concentration of 15 g / L;
[0040] B. Dissolve calcium chloride in water to form a calcium salt solution with a concentration of 0.5 mol / L, slowly add the calcium salt solution dropwise to the sodium alginate solution, and then react for 1 hour to obtain a cross-linked mixture;
[0041] C. The cross-linked mixture was allowed to stand for 3 hours, the jelly was taken out and washed with deionized water, and then dried to obtain a hydrogel;
[0042] S1. preparing nematicidal particles, wherein the nematicidal particles comprise, from the inside to the outside, a seed, a core-shell layer, an intermediate layer, and a surface layer;
[0043] The preparation method of the nematocidal granules comprises the following steps:
[0044] S101, preparing a core-shell layer, dissolving brassinolide in ethanol, dissolving chitosan in acetic acid, and then mixing the two solutions to obtain a mixed solution, spreading seeds on the surface of a sieve, and dispersing the seeds, spraying the mixed solution on the surface of the seeds to form a film layer, which is the core-shell layer, and drying the core-shell layer in the sun for 2-3 minutes to obtain first particles, wherein the concentration of brassinolide in the mixed solution is 3 g / L, and the concentration of chitosan is 2 g / L;
[0045] S102, preparing an intermediate layer, grinding millet ash into powder, and then evenly sprinkling the millet ash powder on the surface of the first particle on the sieve, vibrating the sieve while sprinkling, so that the millet ash powder is evenly wrapped on the surface of the first particle to obtain a second particle, and after being fully dried, continuing to vibrate to sieve out excess millet ash powder on the sieve, and the film layer formed by the millet ash powder on the surface of the second particle is the intermediate layer, and the particle size of the millet ash powder is 75 μm;
[0046] S103, preparing a surface layer, dispersing the hydrogel prepared in step C in water, then adding cartap and mixing by ultrasonic dispersion to obtain a gel solution, wherein the concentration of cartap in the gel solution is 0.2 g / L, placing the second particles in the gel solution and performing ultrasonic dispersion for 10 seconds, then taking out the second particles and placing them on a sieve, continuing to vibrate to shake off the mutually bonded nematicide particles, and then drying to obtain nematicide particles, wherein the gel film formed on the surface of the nematicide particles is the surface layer;
[0047] S2. Sprinkle the nematicide granules into the sowing furrow for planting.
[0048] Example 2
[0049] The only difference between Example 2 and Example 1 is that the concentration of cartap in the gel solution in Example 2 is 0.15 g / L.
[0050] Example 3
[0051] The only difference between Example 3 and Example 1 is that the concentration of cartap in the gel solution in Example 3 is 0.25 g / L.
[0052] Example 4
[0053] The only difference between Example 4 and Example 1 is that the concentration of cartap in the gel solution in Example 4 is 0.3 g / L.
[0054] Comparative Example 1
[0055] The difference between Comparative Example 1 and Example 1 is that in Comparative Example 1, the nematicide is directly sprayed into the soil to kill the nematicide, and then the seeds are sown into the sowing furrow for planting;
[0056] The nematicide comprises cartap, millet ash, brassinolide and water. The concentration of cartap is 0.2 g / L, the concentration of brassinolide is 3 g / L, and 2 g millet ash is added to each liter of the nematicide.
[0057] Comparative Example 2
[0058] The difference between Comparative Example 2 and Example 2 is that the nematicide particles in Comparative Example 2 are a double-layer embedding structure. The preparation method of the nematicide particles in Comparative Example 2 is as follows:
[0059] S101, preparing a first solution, dissolving brassinolide in ethanol, dissolving chitosan in acetic acid, and then mixing the two solutions to obtain a first solution;
[0060] S102, preparing a second solution, grinding millet ash into powder, and then dispersing the millet ash powder in water to form a second solution;
[0061] S103, preparing a third solution, mixing the first solution and the second solution, then adding cartap and mixing evenly, then adding hydrogel and mixing evenly by ultrasonic dispersion to obtain a third solution, placing seeds in the third solution, stirring evenly and standing, then taking out the seeds and drying them to obtain nematode particles;
[0062] The concentration of cartap in the third solution was 0.2 g / L, the concentration of brassinolide was 3 g / L, the concentration of chitosan was 2 g / L, and 2 g of millet ash was added per liter of the third solution.
[0063] Comparative Example 3
[0064] The only difference between Comparative Example 3 and Example 1 is that the nematicidal particles prepared in Comparative Example 3 do not include an intermediate layer.
[0065] Comparative Example 4
[0066] The only difference between Comparative Example 4 and Example 1 is that the nematocidal particles prepared in Comparative Example 4 do not contain a core-shell layer.
[0067] 2. Prevention and Control Experiment
[0068] A plurality of experimental fields were divided in the experimental field and isolated from each other. The same batch of millet seeds were taken and the seeds were treated by the methods of the initial group, Examples 1-4 and Comparative Examples 1-2, respectively. Then, each group of seeds was sown in a separate experimental field, and the same field management parameters were used during planting, such as fertilizer application amount, irrigation amount, etc.
[0069] During the planting period, the growth of millet in each experimental field was observed, and the nematode control rate and germination rate were calculated. The results are shown in Table 1 and Figure 1-2 ,in Figure 1 and Figure 2 The treatment group is Example 2, and the control group is the initial group.
[0070] Table 1
[0071]
[0072] It can be seen from Table 1 that the nematicidal granules prepared by the method of the present invention can effectively improve the control rate of soil nematodes, the nematode control rate of millet is as high as over 90%, and the germination rate is as high as over 95%.
[0073] In Comparative Example 1, due to the direct contact of cartap with millet seeds, the germination rate of seeds was seriously affected, and the germination rate of seeds was less than 80%. In Comparative Example 2, although the hydrogel was used to bind and slowly release cartap to reduce the contact between cartap and seeds, its germination rate was still low.
[0074] At the same time, after the millet in Comparative Example 1 grew for a period of time, since the cartap in the nematicide took effect quickly in the early stage and its lasting effect was short, the nematodes in the soil harmed the millet again in the middle and late stages of millet growth, so its control rate was low.
[0075] The nematicide particles prepared in Comparative Example 3 do not contain an intermediate layer. Due to the lack of dilution and barrier effect of millet wood ash on cartap, the cartap on the surface layer will still affect the germination of seeds during seed germination. However, due to the barrier of the core-shell layer, cartap is prevented from directly contacting the seeds, thereby ensuring the germination rate to a certain extent, which is still higher than that of Comparative Example 1.
[0076] The nematicide particles prepared in Comparative Example 4 do not contain a core-shell layer. Due to the lack of a skeleton formed by the core-shell layer, the middle layer is very easy to separate from the seeds and cannot provide long-term protection for the seeds, causing the seeds to be exposed to a higher concentration of carbofuran, which has an adverse effect on seed germination. In addition, due to the lack of brassinolide and chitosan, the effect of promoting seed germination is weakened, further reducing the germination rate.
[0077] Depend on Figure 1 and Figure 2 It can be seen that the ears of grain treated with the nematode control method of the present invention are fuller and have a lower incidence of purple spike disease.
Claims
1. A method for controlling soil nematodes in millet planting areas, characterized in that: The following steps are involved: S1. preparing nematicidal particles, wherein the nematicidal particles comprise, from the inside to the outside, a seed, a core-shell layer, an intermediate layer, and a surface layer; S2, spreading the nematicide granules into the sowing furrow for planting; The preparation method of the nematocidal granules comprises the following steps: S101, preparing a core-shell layer, dissolving brassinolide in ethanol, dissolving chitosan in acetic acid, and then mixing the two solutions to obtain a mixed solution, spraying the mixed solution on the surface of the seeds to form a film layer, which is the core-shell layer, and drying the core-shell layer in the sun for 2-3 minutes to obtain first particles; S102, preparing an intermediate layer, grinding millet ash into powder, and then uniformly wrapping the millet ash powder on the surface of the first particle, and after thorough drying, obtaining a second particle, wherein the film layer formed by the millet ash powder on the surface of the second particle is the intermediate layer; S103, preparing a surface layer, dispersing the hydrogel in water, then adding cartap and mixing by ultrasonic dispersion to obtain a gel solution, placing the second particles into the gel solution and dispersing them by ultrasonic dispersion, then taking out the second particles, drying and dispersing them to obtain nematicidal particles, wherein the gel film formed on the surface of the nematicidal particles is the surface layer.
2. The method for controlling soil nematodes in millet planting areas according to claim 1, characterized in that: In step S101, the concentration of brassinolide in the mixed solution is 2-4 g / L, and the concentration of chitosan is 1-2 g / L.
3. The method for controlling soil nematodes in millet planting areas according to claim 1, characterized in that: The particle size of the millet wood ash powder is 50-100 μm.
4. The method for controlling soil nematodes in millet planting areas according to claim 1, characterized in that: The concentration of cartap in the gel solution in step S103 is 0.15-0.3 g / L.
5. The method for controlling soil nematodes in millet planting areas according to claim 1, characterized in that: In step S103, the second particles are placed in the gel solution and ultrasonically dispersed for 10-20 seconds.
6. The method for controlling soil nematodes in millet planting areas according to claim 1, characterized in that: The preparation method of the hydrogel comprises the following steps: A. Dissolve sodium alginate in water to form a sodium alginate solution; B. Dissolving calcium salt in water to form a calcium salt solution, adding the calcium salt solution to the sodium alginate solution, reacting for 1-2 hours to obtain a cross-linked mixture; C. Let the cross-linked mixture stand, take out the jelly, wash and dry it to obtain a hydrogel.
7. The method for controlling soil nematodes in millet planting areas according to claim 6, characterized in that: The concentration of sodium alginate in the sodium alginate solution is 10-20 g / L.
8. The method for controlling soil nematodes in millet planting areas according to claim 6, characterized in that: The calcium salt is any one of calcium chloride, calcium iodide and calcium nitrate, and the concentration of the calcium salt in the calcium salt solution is 0.4-0.6 mol / L.
9. The method for controlling soil nematodes in millet planting areas according to claim 6, characterized in that: The volume ratio of the sodium alginate solution to the calcium salt solution in step B is 1:0.5-1.