Granules of abamectin and fluopyram as well as preparation method and application of granules

Abstract

The 3% abamectin and fluopyram granule provided by the invention has the advantages of excellent physical properties, uniform particle size, dust reduction, good fluidity, mechanical operation, uniform pesticide application and improved efficiency. The granules prepared by the invention also have a slow-release effect, a long lasting period and an excellent prevention and treatment effect.

Description

Technical Field

[0001] The present invention relates to the technical field of pesticides, and in particular to a granule of abamectin and fluopyram. Background Art

[0002] Root-knot nematodes are one of the important pests and diseases in China. Root-knot nematodes (Meloidogyne spp.) are a type of plant sedentary endoparasitic nematodes, with many species, a wide host range, strong pathogenicity and wide distribution globally. Root-knot nematodes infect and damage plant roots in the form of hatched second-instar larvae. When conditions are suitable, the hatching process continues to occur, and the whole crop growth cycle is infected multiple times. Therefore, it is difficult to control. The application of pesticides above the ground is uneven due to soil adsorption and other reasons, and the application method is complex.

[0003] The original drug of abamectin is white or light yellow crystals, with a melting point of 150-155°C, a solubility in water of 7-10, and is unstable in strong acids and alkalis. Abamectin is an antibiotic (macrolide disaccharide) insecticide and acaricide, which has stomach toxicity and contact toxicity to insects and mites, and has the advantages of broad-spectrum high efficiency, resistance to resistance, safety for crops, humans and the environment. In recent years, it has also been found that it can be used as an effective nematicide for the control of crop root-knot nematodes, and it is the most widely used and effective pesticide variety in the integrated control of agricultural pests at present. However, it is easily degraded by ultraviolet rays and microorganisms during use, affecting the full play of its efficacy. The current main processing dosage forms are emulsifiable concentrates, microemulsions and aqueous emulsions, and there are also some suspension concentrates and water-dispersible granules.

[0004] Fluopyram is a SDHI (succinate dehydrogenase inhibitor) fungicide and nematicide developed by Bayer CropScience. It has a melting point of 117.5°C, a boiling point of 318°C, good stability, stable photolysis and belongs to a low-toxic pesticide. In addition to being used for the prevention and control of spot defoliation disease, leaf spot disease, gray mold, powdery mildew, sclerotinia, early blight, etc. on vegetables such as grapes, pears, bananas, apples, cucumbers, tomatoes and field crops, it can also be registered on a variety of crops for the control of a variety of nematodes, and it is an efficient, green and low-toxic nematicide. The current main processing dosage forms are suspension concentrates, water-dispersible granules, etc.

[0005] Granules are an excellent dosage form with safe use, convenience and a long effective period. It is a granular preparation composed of a pesticide technical material, a solvent (or water), an adjuvant and a carrier (mineral soil with a certain fineness). When applying the medicine, it has directionality, so that the scattered medicine can fully reach the target organisms and is safe for beneficial organisms such as natural enemies; the medicine does not adhere to the stems and leaves of plants, avoiding direct contact and causing phytotoxicity; there is no dust flying during medicine application, which does not pollute the environment, and can also reduce the amount of medicine attached to or inhaled by the operator's body, avoiding poisoning; it can control the release rate of the active ingredient and extend the effective period.

[0006] Chinese Patent Applications CN110150275A and CN114503990A respectively disclose a suspension and a microcapsule suspension-suspension containing abamectin and fluxapyroxad as active ingredients. However, both are liquid dosage forms and do not have the relevant advantages of granules. Moreover, they are not advantageous in terms of production cost, storage and transportation, etc. In particular, the microcapsule suspension-suspension also requires the use of high-molecular wall materials to prepare microcapsules through complex steps, with complex processes and high costs.

[0007] Chinese Patent Application CN104521951A discloses a pesticide granule with a slow-release effect. Although it mentions that the active ingredient can be selected from abamectin, fluxapyroxad, etc., it does not provide specific examples containing these two active ingredients. Chinese Patent Application CN107509734A discloses a granule with abamectin B2 and fluxapyroxad as active ingredients. However, this application mainly focuses on the synergistic effect of the two active ingredients, does not disclose the specific formula of its granule, nor does it provide the preparation performance indicators of the granule, and it is impossible to determine its dust, shedding rate, etc.

[0008] Therefore, there is still a need to provide a granule of abamectin and fluxapyroxad in combination to overcome the above-mentioned technical problems existing in the prior art. Summary of the Invention

[0009] The present invention provides a granule of abamectin and fluxapyroxad and a preparation method thereof. The prepared product has a long effective period, uniform granules, extremely little dust, a low shedding rate, good fluidity of the product, and can be mechanically operated, meeting the actual needs of controlling root-knot nematodes in agriculture.

[0010] The specific technical solution is as follows:

[0011] A granule containing fluxapyroxad and abamectin, characterized in that, by weight percentage, it contains the following components: fluxapyroxad 2%, abamectin 1%, binder 1-3%, antioxidant 1%, dispersant 0.3-1%, adsorbent 5-10%, and carrier up to 100%.

[0012] Preferably, the 3% abamectin·fluxapyroxad granule is characterized in that, by weight percentage, it contains the following components: fluxapyroxad 2%, abamectin 1%, binder 2%, antioxidant 1%, dispersant 0.7%, adsorbent 8%, and carrier up to 100%.

[0013] The binder is polyvinyl alcohol; the dispersant is ammonium fatty alcohol polyoxyethylene ether sulfate; the antioxidant is 2,6-di-tert-butyl-p-cresol; the carrier is kaolin; the adsorbent is silica white.

[0014] The steps of the preparation method of the granule of the present invention are as follows:

[0015] S1: Take half of the amount of the carrier, adsorbent, abamectin, fluxapyroxad, antioxidant, and mix them according to the formulation composition to obtain Material A.

[0016] S2: Heat the dispersant and spray it onto Material A under stirring conditions to obtain Material B.

[0017] S3: Add half of the amount of the carrier used in the formulation to Material B, mix and stir, then pulverize by air flow and mix again to obtain Material C.

[0018] S4: Dissolve the binder in water and spray it into Material C, then knead, granulate and dry to obtain the product.

[0019] The 3% abamectin·fluxapyroxad granule described in the present invention can be used to control root-knot nematodes.

[0020] Advantageous technical effects of the present invention:

[0021] The granule prepared by the present invention has excellent physical properties, with uniform particle size and good particle fluidity. It can be mechanically operated, the application is uniform, the efficiency is improved, and it has a slow-release effect and a long effective period, and has excellent control effects. These advantages are due to the specific preparation method used in the present invention, that is, adding the carrier step by step, and spraying the specific dispersant and binder successively. Compared with the preparation method of mixing all components for granulation, or using other binders such as polyvinylpyrrolidone, carboxymethyl starch or other dispersants such as triphenylvinylphenol polyoxyethylene ether, castor oil polyoxyethylene ether, etc., it can greatly reduce dust, has a low shedding rate, good product fluidity, and is more suitable for mechanical operation. Specific embodiments

[0022] The following further explains and illustrates the present invention in combination with specific embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

[0023] Formulation examples

[0024] Polyvinyl alcohol GH-20S, produced by Nippon Gohsei Chemical Industry Co., Ltd.

[0025] Silica white Carplex#80, produced by Evonik Industries AG.

[0026] 2,6-Di-tert-butyl-p-cresol (BHT), produced by LANXESS.

[0027] Ammonium lauryl ether sulfate (AESA), produced by BASF.

[0028] Kaolin Hydrite 121S, produced by Imerys, France;

[0029] Carboxymethyl starch, produced by Hebei Chuangzhiyuan Biotechnology Co., Ltd.;

[0030] Polyvinylpyrrolidone PVP k30, produced by Gongbike New Materials Technology (Shanghai) Co., Ltd.

[0031] Preparation methods for Examples 1 - 3:

[0032] S1: Take half of the amount of kaolin in the formula, silica white, abamectin technical, fluxapyroxad technical, 2,6 - di - tert - butyl - p - cresol, and mix them according to the formula composition by stirring to obtain Material A;

[0033] S2: Heat ammonium lauryl ether sulfate AESA and spray it onto Material A under stirring conditions to obtain Material B.

[0034] S3: Add the other half of the amount of kaolin in the formula to Material B, mix and stir, and then mix again after air - flow pulverization to obtain Material C.

[0035] S4: Dissolve polyvinyl alcohol in water and spray it into Material C, then knead, granulate and dry to obtain the product.

[0036] The preparation methods for Comparative Examples 1 - 3 refer to the method of this application, with the difference being the use of other binders or dispersants; the preparation method for Comparative Example 4 is to stir - mix kaolin, silica white, abamectin technical, fluxapyroxad technical, 2,6 - di - tert - butyl - p - cresol according to the formula composition, conduct air - flow pulverization, then spray ammonium lauryl ether sulfate and polyvinyl alcohol, and finally knead, granulate and dry.

[0037] Table 1 Example Formulations

[0038]

[0039]

[0040] The above - mentioned examples and comparative examples were tested for quality indicators, and the results are shown in Table 2. The determination of the active ingredient content was carried out by HPLC method; the determination of pH value was carried out according to GB / T1601 - 1993; the determination of pesticide moisture was carried out according to GB / T1600 - 2001; the determination of pesticide bulk density was carried out according to GB / T33810 - 2017; the determination of particulate pesticide dust was carried out according to GB / T30360 - 2013; the detection method for the shedding rate of pesticide granules was carried out by the drum method; the thermal storage stability test was carried out according to GB / T19136 - 2003.

[0041] Table 2 Quality Index Test Results

[0042]

[0043] The quality test results show that the products prepared in Comparative Examples 1 and 2 have a small amount of dust, while Examples 1-3 and Comparative Example 3 are dust-free and have a low shedding rate. The formula of Comparative Example 4 is the same as that of Example 1, but the preparation method is different, resulting in that the particle size range, bulk density, and shedding rate indexes do not meet the standards, and the dust increases. Without being bound by any theory, the inventors believe that it may be due to the fact that Comparative Example 4 does not add carriers in batches, resulting in too much material being processed simultaneously, and the particle size of airflow crushing is not uniform enough, and when spraying fatty alcohol polyoxyethylene ether ammonium sulfate and polyvinyl alcohol, it is difficult to spray thoroughly and evenly. The bulk density is too large, resulting in insufficient particle fluidity and poor mechanical operability. And further experiments have found that if the airflow crushing time is extended, the material is crushed too finely, which will also cause too much dust to be generated during final drying.

[0044] The results showed that the physical properties of 3% avermectin·fluopyram granules using polyvinyl alcohol as a binder were better than those of carboxymethyl starch and polyvinyl pyrrolidone. The specific preparation method also made the product have good fluidity and suitable for mechanical operation.

[0045] Biological Example Test name: Field efficacy test of 3% avermectin·fluopyram granules for controlling cucumber root-knot nematode disease Test time: May 22, 2022-July 28, 2022 Test crop: cucumber, variety: Fuyang No. 2. Cucumber seedlings were raised on April 27 and transplanted on May 22, with the drug applied before transplanting.

[0046] Test target: Cucumber root-knot nematode disease, a common disease on cucumber crops in the test field. Its pathogen is root-knot nematode, and the dominant species is southern root-knot nematode.

[0047] Test / control agent: 30% fluopyram·avermectin granules prepared in Examples 1-3 and Comparative Examples 1-4.

[0048] Test site conditions: Xizhenggang Village, Yandian Township, Feixi County, Hefei City, Anhui Province. The test site is flat and the soil is a nutrient-rich yellow-white sandy mud field.

[0049] Experimental design: The experiment has 8 treatments and 4 replications. The plot area is 20m 2 ; Number of repetitions: 4 times.

[0050] Application method and time: Before transplanting cucumbers, mix the agent with soil and spread it (mix it with fine soil and spread it on the bed surface, mix 20 kg of fine soil per mu, and shallowly till it), and apply the agent once. After application, mix the agent and soil thoroughly; apply the agent on May 22, 2022, once, and spread the same amount of soil in the blank control area.

[0051] Investigation methods, time, and frequency: First investigation: Collect soil samples from the plots before applying pesticides to investigate the base number of second-instar larvae in the soil. The investigation time for this experiment was May 22, 2022; Second investigation: 35 days after applying pesticides, collect soil samples from the plots to investigate the number of second-instar larvae in the soil. The investigation time for this experiment was June 26, 2022; Third investigation: 67 days after applying pesticides (July 28, 2022), before pulling out the cucumber plants, investigate the disease index.

[0052] Investigation methods

[0053] 1) Investigation of the population density of second-instar Meloidogyne larvae:

[0054] Sampling: Use the "Z" method to take 5 samples per plot. At each sampling point, use a soil sampler to collect soil around the rhizosphere of the crop at a depth of 10 - 20 cm and put the soil samples into plastic woven bags.

[0055] Separation: Mix the soil samples from each plot evenly. After 2 - 3 times of quartering, take 500 grams for use. Use the improved shallow dish method to separate nematodes. First, take a plastic mesh basket with a diameter of 18 cm and a depth of 6 cm, wrap the 500 - gram soil sample containing nematodes with four layers of gauze and gently place it in the mesh basket. Then, put the mesh basket into a supporting plastic basin, add clear water to submerge the soil, soak for 24 hours, take out the mesh basket, and filter the water in the plastic basin through a funnel lined with two layers of gauze. Let the filtrate stand for 3 hours, and gently suck out the supernatant using the siphon method, leaving about 300 - 400 ml of nematode solution.

[0056] Counting: Count the nematode solution obtained above 10 times. Each time, use a micropipette to suck out 20 - 40 ml of the liquid and place it in a Petri dish, and observe and count it under a stereomicroscope. Before each counting, heat the Petri dish on an alcohol lamp until slightly hot to reduce the activity of nematodes. The total population density is expressed in units of: heads / 500 grams of soil.

[0057] 2) Investigation of the disease index of cucumber plants:

[0058] Use the parallel jump method to take 5 samples per plot. At each sampling point, investigate 6 plants. Gently rinse the roots and stems of the cucumber plants in clear water to remove the soil, and observe the disease level. Record the disease situation and disease grade of each plant, and calculate the disease index and control effect.

[0059] Grading criteria:

[0060] Grade 0: No root knots on the roots;

[0061] Grade 1: <10% of the roots have root knots;

[0062] Grade 2: 11% - 25% of the roots have root knots;

[0063] Grade 3: 26% - 50% of the roots have root knots;

[0064] Level 4: Root-knots are present on 51%-75% of the roots;

[0065] Level 5: Root-knots are present on more than 76% of the roots.

[0066] Pharmacodynamic calculation method

[0067]

[0068] Test results:

[0069] Safety: The test agent is safe for growth at the test dose, and no phytotoxicity occurs.

[0070] Mechanical operability: The product prepared in Example 1 has significantly better fluidity than other groups, and the product prepared in Example 2 is the second best. The product of Example 1 is suitable for mechanical operation. The inventor believes that the binding force of polyvinyl alcohol is better than that of polyvinylpyrrolidone and carboxymethyl starch. Polyvinyl alcohol can make the granules have good molding, uniform granules, stable flow rate during mechanical operation, and uniform field application; adding silica white can improve the fluidity of the granules, and when the silica white content in the formula is 8%, its fluidity is better than 4%.

[0071] Table 3 Control effects of examples and comparative examples on cucumber root-knot nematodes

[0072]

[0073] Note: The control effects in the table were analyzed by variance using Duncan's new multiple range method in DPS 7.05 software. Different capital and lowercase letters indicate significant differences at the 1% and 5% levels, respectively.

[0074] Table 3 results show that the control effects of Example 1 on cucumber root-knot nematodes are the highest after 35 days and 67 days of application. The control effects of Example 2 and 3 are slightly lower. By comparing Example 1 with Comparative Examples 1 and 2, it can be seen that the product with polyvinyl alcohol as the binder has a higher control effect than carboxymethyl starch and polyvinylpyrrolidone. Without being bound by any theory, the inventor believes that it may be due to higher dust and shedding rates, resulting in a decrease in the active ingredient actually applied to the field.

[0075] In Comparative Example 3, ammonium lauryl ether sulfate was not added as a dispersant, and the pharmacodynamic effect of the product was significantly lower than that of Examples 1-3 and Comparative Examples 1-2 with the addition of ammonium lauryl ether sulfate (at the P = 0.05 level).

[0076] The control effect of Comparative Example 4 is the lowest. Without being bound by any theory, the inventor believes that it should be due to excessive dust and shedding rates, as well as poor mechanical operability, resulting in a significant decrease in the active ingredient actually applied to the field.

[0077] In summary, the 30% fluxapyroxad·abamectin granule prepared in Example 1 shows the best performance in terms of control effect and mechanical operability.

[0078] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A 3% abamectin·fluxapyroxad granule, characterized in that, By weight percentage, it contains the following components: fluxapyroxad 2%, abamectin 1%, binder 1-3%, antioxidant 1%, dispersant 0.3-1%, adsorbent 5-10%, and carrier up to 100%.

2. The 3% abamectin·fluopyram granule according to claim 1, characterized in that, By weight percentage, it contains the following components: fluxapyroxad 2%, abamectin 1%, binder 2%, antioxidant 1%, dispersant 0.7%, adsorbent 8%, and carrier up to 100%. The binder is polyvinyl alcohol, the dispersant is ammonium fatty alcohol polyoxyethylene ether sulfate, the antioxidant is 2,6-di-tert-butyl-p-cresol, the carrier is kaolin, and the adsorbent is silica white.

3. The preparation method of the 3% abamectin·fluopyram granule according to any one of claims 1-2, characterized in that, The steps are as follows: S1: Take half of the amount of the carrier, adsorbent, abamectin, fluxapyroxad, and antioxidant according to the formula composition, and stir and mix to obtain material A; S2: Heat the dispersant and spray it onto material A under stirring conditions to obtain material B; S3: Add another half of the amount of the carrier according to the formula to material B, mix and stir, and after airflow comminution, mix again to obtain material C; S4: Dissolve the binder in water and spray it into material C, knead, granulate and dry to obtain the product.

4. Use of the 3% abamectin·fluxapyroxad granule according to any one of claims 1-2 or the 3% abamectin·fluxapyroxad granule prepared by the preparation method of claim 3 in controlling root-knot nematodes.

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