Carfentrazone-ethyl-containing suspension concentrate and preparation method and application thereof

Abstract

The present application relates to the technical field of pesticides, in particular to a kind of flumioxazin-containing suspending agent and its preparation method and application.The suspending agent includes: flumioxazin 20-40wt%, dispersing agent 3-5wt%, wetting agent 2-3wt%, antifoaming agent 0.05-0.2wt%, inorganic salt 0.08-1.2wt%, thickening agent 0.9-1.3wt%, other auxiliary materials 0-0.5wt%, and the balance is water.The flumioxazin-containing suspending agent of the present application has excellent stability and the advantage of long effective time of active ingredient.

Description

Technical Field

[0001] This invention relates to the field of pesticide technology, specifically to a benzoxazine suspension concentrate, its preparation method, and its application. Background Technology

[0002] Benzotrione, chemically known as 4-[3-(4,5-dihydroisoxazole-3-yl)-2-methyl-4-methylsulfonyl]-1-methyl-5-hydroxy-1H-pyrazole, belongs to the class of p-hydroxyphenylpyruvate dioxygenase (HPPD) inhibitors and may be effective in controlling grasses and broadleaf weeds in cornfields.

[0003] Water-based suspension concentrates have good environmental protection properties, but due to the strong hydrophilicity of benzoxazine and its high solubility in water, general dispersants are prone to desorption from the surface of the active ingredient, thus losing their effectiveness. At the same time, during long-term storage, particle growth or effective crystallization may occur, and the effective time of benzoxazine suspension concentrates is relatively short when used. Summary of the Invention

[0004] The purpose of this invention is to provide a novel benzoxazine-containing suspension concentrate, its preparation method, and its application. This benzoxazine-containing suspension concentrate exhibits excellent stability.

[0005] To achieve the above objectives, the first aspect of the present invention provides a benzoxazine suspension, wherein, by mass percentage, the suspension comprises: 20-40 wt% benzoxazine technical grade, 3-5 wt% dispersant, 2-3 wt% wetting agent, 0.05-0.2 wt% defoamer, 0.08-1.2 wt% inorganic salt, 0.9-1.3 wt% thickener, 0-0.5 wt% other excipients, and the balance being water.

[0006] The second aspect of the present invention provides a method for preparing the benzoxazine suspension of the present invention, the method comprising: grinding a dispersion containing benzoxazine technical, dispersant, wetting agent, defoamer, inorganic salt, other excipients and water at least once to form a grinding material, and then adding a thickener and shearing.

[0007] The third aspect of this invention provides the application of the benzoxazine suspension concentrate of this invention in the control of grass and broadleaf weeds in sorghum fields.

[0008] Compared with the prior art, the present invention has at least the following beneficial effects:

[0009] (1) The benzoxazine-containing suspension in this invention has excellent cold and hot storage properties;

[0010] (2) The effective time of the active ingredient in the benzoxazolone suspension in this invention is long. Detailed Implementation

[0011] To facilitate a clearer understanding of the technical solutions and effects of this invention, the following detailed description, in conjunction with specific embodiments, is provided. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. In case of conflict, the definitions in this specification shall prevail.

[0012] The first aspect of the present invention provides a benzoxazine suspension, wherein, by mass percentage, the suspension comprises: 20-40 wt% benzoxazine technical material, 3-5 wt% dispersant, 2-3 wt% wetting agent, 0.05-0.2 wt% defoamer, 0.08-1.2 wt% inorganic salt, 0.9-1.3 wt% thickener, 0-0.5 wt% other excipients, and the balance being water.

[0013] In this invention, the interaction between the various components in the suspension, especially the interaction between the components according to the above-mentioned mass content, can better increase the stability of the suspension containing benzoxazine. In particular, the combined action of the dispersant and inorganic salt in the components can further increase the stability of the benzoxazine suspension.

[0014] In this invention, in order to further enhance the overall effect of the benzoxazine suspension, in a preferred embodiment, the suspension comprises, by mass percentage: 30 wt% benzoxazine technical grade, 4 wt% dispersant, 2.5 wt% wetting agent, 0.1 wt% defoamer, 1 wt% inorganic salt, 1.12 wt% thickener, 0.2 wt% other excipients, and the balance being water.

[0015] In one embodiment, the dispersant is selected from one or more of sodium lignosulfonate, ethylene oxide-propylene oxide block copolymer, carboxylate polymer, sodium methylene bis(thalassium)sulfonate, Morwet D-425 and terspense-2500, preferably Morwet D-425.

[0016] In one embodiment, the wetting agent is selected from fatty alcohol polyoxyethylene ether.

[0017] In a preferred embodiment, the fatty alcohol polyoxyethylene ether is selected from C10-C20 alcohol polyoxyethylene ether, preferably from C10-C15 alcohol polyoxyethylene ether, and more preferably from C13 alcohol polyoxyethylene ether.

[0018] The C13 alcohol polyoxyethylene ether used in this invention is a commercially available brand. TO 8 (BASF).

[0019] In this invention, fatty alcohol polyoxyethylene ether is a nonionic surfactant that can provide steric hindrance and better interact with the dispersant of this invention to adsorb and encapsulate the drug particles.

[0020] The preparation of benzoxazine suspension often requires stirring, and high foaming is a common problem during stirring. This problem can lead to the benzoxazine suspension failing to reach the pesticide dilution level during use, resulting in reduced efficacy. Therefore, an antifoaming agent is added to the benzoxazine suspension. Organosilicon defoamers have excellent stability and strong defoaming power. In a preferred embodiment, the defoaming agent is an organosilicon defoamer. There are no special restrictions on the specific type of organosilicon defoamer, such as SAG1522, SAG1572, and BS-163, with SAG1522 being preferred.

[0021] In one embodiment, the inorganic salt is selected from at least one of sodium chloride, potassium chloride, potassium pyrophosphate, sodium pyrophosphate, and potassium citrate, preferably sodium chloride.

[0022] Benzoflubenzuron's active ingredient is highly hydrophilic and has high solubility in water, which increases exponentially with increasing pH. In existing technologies, benzoflubenzuron is formulated as an SC (surface suspension) because the high hydrophilicity of the active ingredient makes it easy for the dispersant to desorb from the surface of the active ingredient, thus losing its effectiveness. Furthermore, the high water solubility of the active ingredient can lead to particle growth or crystallization of the active ingredient during long-term storage. However, the benzoflubenzuron-containing suspension of this invention exhibits excellent stability during long-term storage. The inventors speculate that this is because: firstly, the lipophilic and correspondingly structured sodium naphthalene sulfonate formaldehyde condensate dispersant (Morwet D-425) used in this invention helps anchor and desorb the surfactant on the active ingredient surface; secondly, the addition of inorganic salts, especially sodium chloride, to the system can shield the electrostatic repulsion between the dispersant and benzoflubenzuron, thereby increasing the adsorption of dispersant molecules on the particle surface.

[0023] In this invention, the addition of a thickener can adjust the rheological properties and flowability of the benzoxazine-containing suspension. In a preferred embodiment, the thickener is selected from at least one of magnesium aluminum silicate, silica, sodium alginate, xanthan gum, and polyvinyl alcohol.

[0024] In a more preferred embodiment, the thickener is a combination of magnesium aluminum silicate and xanthan gum, preferably with a mass ratio of magnesium aluminum silicate to xanthan gum of 1:(0.1-0.15), and more preferably 1:0.12.

[0025] The magnesium aluminum silicate and xanthan gum in this invention can be obtained commercially. Preferably, the magnesium aluminum silicate is purchased from Suzhou Guojian Huitou Mineral New Materials Co., Ltd., with the grade SF-04, and the xanthan gum is purchased from Zhongxuan Biochemical Co., Ltd.

[0026] In this invention, magnesium aluminum silicate alone has a poor ability to increase the viscosity of benzoxazine-containing suspensions, and the ability to increase the viscosity of formulations by using a single thickener is also poor. In this application, a specific ratio of magnesium aluminum silicate and xanthan gum is used as a thickener, which can better balance the suspension rate and pourability of benzoxazine-containing suspensions.

[0027] In this invention, other necessary excipients may be added to the suspending agent as needed. In one embodiment, the other excipients include preservatives, and there is no particular limitation on the specific type of preservative. Preferably, the preservative is a BIT preservative, and more preferably, the BIT preservative is grade G20S.

[0028] In a preferred embodiment, the preservative content in the benzoyl sulfadiazine suspension is 0.05-0.15 wt%, preferably 0.1 wt%.

[0029] In a preferred embodiment, the other excipients include an antifreeze agent.

[0030] In a more preferred embodiment, the antifreeze is an ionic liquid, preferably an imidazole salt ionic liquid, more preferably 1-butyl-3-methylimidazolium iodide or 1-butyl-3-methylimidazolium chloride, and even more preferably 1-butyl-3-methylimidazolium iodide.

[0031] In a preferred embodiment, the antifreeze content in the benzoxazine suspension is 0.05-0.15 wt%, preferably 0.1 wt%.

[0032] Currently, the most commonly used antifreeze agents in existing technologies are alcohol-based antifreeze agents, such as ethylene glycol. However, the volatilization and degradation of alcohols are limited, and alcohols can accumulate in seeds and seedlings, causing phytotoxicity such as inhibiting aerobic respiration and disrupting nutrient synthesis. The inventors of this application discovered that using ionic liquids as antifreeze agents in this invention not only increases the low-temperature storage performance of benzoxazine suspensions but also enhances the efficacy of benzoxazine in the suspensions. The inventors speculate that this may be because ionic liquids are metal salts with extremely low freezing points and can provide freely moving cations and anions. However, the ionic liquid system in this invention has a certain solubilizing effect on benzoxazine, which reduces the effective time of the benzoxazine suspension. The applicants unexpectedly discovered that the addition of a certain amount of inorganic salts can reduce the solubility of the active ingredient in water, thus mitigating the drawbacks of ionic liquids.

[0033] The second aspect of the present invention provides a method for preparing the benzoxazine suspension of the present invention, the method comprising: grinding a dispersion containing benzoxazine technical, dispersant, wetting agent, defoamer, inorganic salt, other excipients and water at least once to form a grinding material, and then adding a thickener and shearing.

[0034] In this invention, there are no special restrictions on the method of obtaining the dispersion containing benzoxazine technical, dispersant, wetting agent, defoamer, inorganic salt, other excipients and water. For example, it can be obtained by homogenizing and shearing benzoxazine technical, wetting agent, dispersant, defoamer, inorganic salt, other excipients and water at 1800-2500 rpm for 20-50 min.

[0035] In this invention, there are no special limitations on the conditions for shearing with the addition of a thickener, but it is preferred to shear at 1800-2500 rpm for 20-50 minutes.

[0036] In a preferred embodiment, a dispersion containing benzoyl sulfadiazine technical, dispersant, defoamer, inorganic salt, other excipients and water is first ground once to a particle size of 270-400 mesh to obtain a first grinding material. Then, half the mass of the first grinding material is taken and ground a second time to a particle size of 650-800 mesh to obtain a second grinding material. The first grinding material and the second grinding material are mixed to obtain a grinding material.

[0037] During the experiment, the inventors of this application found that when the dispersant was directly ground to a particle size of 650-800 mesh, the thermal storage phenomenon of the benzoxazine suspension was poor. This may be because at higher temperatures, the thermal motion of the smaller-sized active ingredient aggregates, and the wetting and dispersing agent with the same total content cannot fully cover the surface of the active ingredient particles, making the active ingredient easier to precipitate. The inventors' method of grinding twice can better increase the thermal storage phenomenon of the benzoxazine suspension and prolong the effective time of the pesticide. This may be because active ingredients of different particle sizes can form a card-like binding network structure with magnesium aluminum silicate in the aqueous medium more tightly in the system. At the same time, magnesium aluminum silicate can better coat the active ingredients of different particle sizes, so that the efficacy is slowly released, thereby prolonging the effective time of the pesticide.

[0038] The third aspect of this invention provides the application of the benzoxazine suspension concentrate of this invention in the control of grass and broadleaf weeds in sorghum fields.

[0039] In a preferred embodiment, the application is performed on sorghum at the 3-5 leaf stage.

[0040] The present invention will be specifically described below through examples. In the following examples, magnesium aluminum silicate was purchased from Suzhou Guojian Huitou Mineral New Materials Co., Ltd., with the grade SF-04; xanthan gum was purchased from Zhongxuan Biochemical Co., Ltd.

[0041] Example 1

[0042] By weight percentage, take 30 wt% of benzoxazine technical grade, 4 wt% of Morwet D-425 dispersant, and C13 alcohol polyoxyethylene ether (brand name: TO 8 (BASF) 2.5wt%, SAG1522 defoamer 0.1wt%, sodium chloride 1wt%, magnesium aluminum silicate 1wt%, xanthan gum 0.12wt%, BIT preservative 0.1wt%, 1-butyl-3-methylimidazolium iodide 0.1wt%, balance water, for later use;

[0043] The technical grade of benzoxazine, Morwet D-425 dispersant, and C13 alcohol polyoxyethylene ether (brand name: A dispersion was obtained by homogenizing and shearing TO 8 (BASF), SAG1522 defoamer, sodium chloride, BIT preservative, 1-butyl-3-methylimidazolium iodide, and water at 2000 rpm for 30 min.

[0044] The dispersion is ground to a particle size of 325 mesh to obtain the first grinding material. Half of the mass of the first grinding material is ground a second time to a particle size of 800 mesh to obtain the second grinding material. The first grinding material and the second grinding material are mixed to obtain the grinding material.

[0045] Magnesium aluminum silicate and xanthan gum were added to the grinding material and homogenized and sheared at 2000 rpm for 30 min to obtain a suspension containing 30% benzoxazine.

[0046] Example 2

[0047] By weight percentage, take 30 wt% of benzoxazine technical grade, 4.5 wt% of Morwet D-425 dispersant, and C13 alcohol polyoxyethylene ether (brand name: TO 8 (BASF) 3wt%, SAG1522 defoamer 0.1wt%, sodium chloride 1.2wt%, magnesium aluminum silicate 1wt%, xanthan gum 0.12wt%, BIT preservative 0.1wt%, 1-butyl-3-methylimidazolium iodide 0.1wt%, balance water, for later use;

[0048] The technical grade of benzoxazine, Morwet D-425 dispersant, and C13 alcohol polyoxyethylene ether (brand name: The mixture was prepared by homogenizing and shearing TO 8 (BASF), SAG1522 defoamer, sodium chloride, BIT preservative, 1-butyl-3-methylimidazole iodide, and water at 2500 rpm for 20 min.

[0049] The dispersion is ground to a particle size of 325 mesh to obtain the first grinding material. Half of the mass of the first grinding material is ground a second time to a particle size of 800 mesh to obtain the second grinding material. The first grinding material and the second grinding material are mixed to obtain the grinding material.

[0050] Magnesium aluminum silicate and xanthan gum were added to the grinding material and homogenized and sheared at 2500 rpm for 20 min to obtain a suspension containing 30% benzoxazine.

[0051] Example 3

[0052] By weight percentage, take 30 wt% of benzoxazine technical grade, 4 wt% of Morwet D-425 dispersant, and C13 alcohol polyoxyethylene ether (brand name: TO 8 (BASF) 2wt%, SAG1522 defoamer 0.08wt%, sodium chloride 1wt%, magnesium aluminum silicate 1wt%, xanthan gum 0.12wt%, BIT preservative 0.1wt%, 1-butyl-3-methylimidazolium iodide 0.1wt%, balance water, for later use;

[0053] The technical grade of benzoxazine, Morwet D-425 dispersant, and C13 alcohol polyoxyethylene ether (brand name: A dispersion was obtained by homogenizing and shearing TO 8 (BASF), SAG1522 defoamer, sodium chloride, BIT preservative, 1-butyl-3-methylimidazolium iodide and water at 1800 rpm for 50 min.

[0054] The dispersion is ground to a particle size of 325 mesh to obtain the first grinding material. Half of the mass of the first grinding material is ground a second time to a particle size of 800 mesh to obtain the second grinding material. The first grinding material and the second grinding material are mixed to obtain the grinding material.

[0055] Magnesium aluminum silicate and xanthan gum were added to the abrasive and homogenized by shearing at 1800 rpm for 50 min to obtain a suspension containing 30% benzoxazine.

[0056] Example 4

[0057] By weight percentage, take 30 wt% of benzoxazine technical grade, 4 wt% of Morwet D-425 dispersant, and C13 alcohol polyoxyethylene ether (brand name: TO 8 (BASF) 2.5wt%, SAG1522 defoamer 0.1wt%, sodium chloride 1wt%, magnesium aluminum silicate 1wt%, xanthan gum 0.12wt%, BIT preservative 0.1wt%, balance water, for later use;

[0058] The technical grade of benzoxazine, Morwet D-425 dispersant, and C13 alcohol polyoxyethylene ether (brand name: A dispersion was obtained by homogenizing and shearing TO 8 (BASF), SAG1522 defoamer, sodium chloride, BIT preservative and water at 2000 rpm for 30 min.

[0059] The dispersion is ground to a particle size of 325 mesh to obtain the first grinding material. Half of the mass of the first grinding material is ground a second time to a particle size of 800 mesh to obtain the second grinding material. The first grinding material and the second grinding material are mixed to obtain the grinding material.

[0060] Magnesium aluminum silicate and xanthan gum were added to the grinding material and homogenized and sheared at 2000 rpm for 30 min to obtain a suspension containing 30% benzoxazine.

[0061] Example 5

[0062] By weight percentage, take 30 wt% of benzoxazine technical grade, 4 wt% of Morwet D-425 dispersant, and C13 alcohol polyoxyethylene ether (brand name: TO 8 (BASF) 2.5wt%, SAG1522 defoamer 0.1wt%, sodium chloride 1wt%, magnesium aluminum silicate 1wt%, xanthan gum 0.12wt%, BIT preservative 0.1wt%, 1-butyl-3-methylimidazolium iodide 0.1wt%, balance water, for later use;

[0063] The technical grade of benzoxazine, Morwet D-425 dispersant, and C13 alcohol polyoxyethylene ether (brand name: A dispersion was obtained by homogenizing and shearing TO 8 (BASF), SAG1522 defoamer, sodium chloride, BIT preservative, 1-butyl-3-methylimidazolium iodide, and water at 2000 rpm for 30 min.

[0064] The dispersion was ground to a particle size of 325 mesh to obtain the first grinding material, and the first grinding material was ground a second time to a particle size of 800 mesh to obtain the second grinding material;

[0065] Magnesium aluminum silicate and xanthan gum were added to the second grinding material and homogenized and sheared at 2000 rpm for 30 min to obtain a suspension containing 30% benzoxazine.

[0066] Comparative Example 1

[0067] By weight percentage, take 30 wt% of benzoxazine technical grade, 4 wt% of Morwet D-425 dispersant, and C13 alcohol polyoxyethylene ether (brand name: TO 8 (BASF) 2.5wt%, SAG1522 defoamer 0.1wt%, magnesium aluminum silicate 1wt%, xanthan gum 0.12wt%, BIT preservative 0.1wt%, balance water, for later use;

[0068] The technical grade of benzoxazine, Morwet D-425 dispersant, and C13 alcohol polyoxyethylene ether (brand name: A dispersion was obtained by homogenizing and shearing TO 8 (BASF), SAG1522 defoamer, BIT preservative and water at 2000 rpm for 30 min.

[0069] The dispersion is ground to a particle size of 325 mesh to obtain the first grinding material. Half of the mass of the first grinding material is ground a second time to a particle size of 800 mesh to obtain the second grinding material. The first grinding material and the second grinding material are mixed to obtain the grinding material.

[0070] Magnesium aluminum silicate and xanthan gum were added to the grinding material and homogenized and sheared at 2000 rpm for 30 min to obtain a suspension containing 30% benzoxazine.

[0071] Performance Evaluation

[0072] I. Field efficacy tests were conducted on the 30% benzoxazine suspensions in Examples 1-3 and 5. The control agent was a commercially available 38% atrazine suspension.

[0073] 1. Basic Information of the Experiment

[0074] 1.1 Test Basis: This test follows the "Good Manufacturing Practice for Pesticide Registration Tests", "NY / T 1464.61-2016 Guidelines for Field Efficacy Testing of Pesticides Part 61: Application of Herbicides to Sorghum Fields for Weeds" and HLJZB / BH012-2018 "Standard Operating Procedures for Herbicide Control of Sorghum Weeds".

[0075] 2. Environmental and facility cultivation conditions

[0076] 2.1. Location of the experimental site: Heilongjiang Provincial Agricultural Science Experimental Park, Minzhu Township, Harbin City.

[0077] 2.2 Experimental target information: The main annual grass weeds were barnyard grass (Echinochloacrus galli), and the main annual broadleaf weeds were lambsquarters (Chenopodium album), Polygomumbungeanum, Abutilontheophrasti, and Solamum nigrum.

[0078] 2.3. Experimental crop, variety, and growth status: Sorghum, variety Longza 25, sown on May 21st at a seeding rate of 9 kg / hm². 3 The sorghum grew normally when the pesticide was applied.

[0079] 2.4. Soil type: The test soil was black soil, medium texture, with an organic matter content of 3.62% and a pH of 6.79. The previous crop was corn, and the soil was plowed, fertilized, and raised in autumn with a ridge spacing of 65cm. The ground balloon was re-erected on May 16th.

[0080] 2.5 Water and fertilizer management in the experimental field: Normal field water and fertilizer management was carried out.

[0081] 2.6 Meteorological Data: The pesticide was applied on June 19th. The day of application was cloudy with an average daily wind speed of 2.3 m / s. The average daily temperature was 18.7℃, with a high of 21.6℃ and a low of 14.2℃. The average relative humidity was 60%. In the 10 days prior to application, the average temperature was 19.3℃, with a high of 28.3℃ and a low of 10.9℃. There were 3 days of cooling, and the cumulative rainfall was 20.6 mm. In the 10 days following application, the average temperature was 19.4℃, with a high of 27.7℃ and a low of 14.7℃. There were 7 days of cooling, and the cumulative rainfall was 61.6 mm.

[0082] 3. Experimental Design and Arrangement

[0083] 3.1 The dosage and numbering of the medicines are shown in Table 1.

[0084] Table 1

[0085]

[0086] 3.2 Layout of the residential area

[0087] 3.2.1 The community layout is as follows:

[0088]

[0089]

[0090] 3.2.2, Area and Repetition of Zone: 20m of cotton knots in the zone. 2 Number of repetitions: 4.

[0091] 3.3 Application Method

[0092] 3.3.1 Application period and method: Spray the stems and leaves after the sorghum seedlings emerge.

[0093] 3.3.2 Application Equipment: A backpack-mounted compressor sprayer specifically designed for residential areas is used for application. The spray width is 2m, with 4 flat fan-shaped nozzles and a working pressure of 4kg / cm². 2 .

[0094] 3.3.3 Application Time and Frequency: Apply the pesticide on June 19th, when sorghum is at the 3-5 leaf stage. For barnyard grass at the 2-4 leaf stage; for broadleaf weeds such as lambsquarters and knotweed at the 2-4 cm stage; and for velvetleaf and black nightshade at the 2-3 leaf stage. Spray once throughout the entire growth period.

[0095] 3.3.4. Usage capacity: 450 liters / hectare for spraying.

[0096] 3.4 Survey Methods, Time, and Frequency

[0097] 3.4.1 Survey time and frequency: First survey: survey the base number of weeds before application; Second survey: survey the number of weeds and control efficacy 15 days after application; Third survey: survey the number of weeds and control efficacy and fresh weight control efficacy 30 days after application.

[0098] 3.4.2 Survey Method: In accordance with Part 61 of the Guidelines, four points were surveyed in each area, with each point measuring 0.25m. 2 The number of plants or fresh weight of each weed species was calculated for control efficacy. One week after application, observations showed that annual grasses and broadleaf weeds in each treatment area of ​​the 30% benzoyl peroxide suspension at different dosages turned from green to yellowish-white, and the leaves of broadleaf weeds such as lambsquarters, knotweed, velvetleaf, and black nightshade began to wither. Two weeks after application, knotweed, velvetleaf, and black nightshade were basically dead. Some weeds and lambsquarters remained in each treatment area, with growth inhibited. The number of remaining weeds gradually decreased with increasing dosage. Later observations showed that the remaining barnyard grass and lambsquarters in each treatment area could resume normal growth.

[0099] 3.4.3 Calculation method of efficacy: According to Part 61 of the Guidelines, the formula (1) in the standard number NY / T1464.61-2016 is used: Control effect (%) = (CK-PT) / CK*100, where: PT---the number of grasses remaining in the treatment area (or fresh weight), CK--the number of grasses alive in the blank control area (or fresh weight).

[0100] 3.5 Direct impact on crops

[0101] 3.5.1 Survey Time and Frequency

[0102] First treatment: 1-2 weeks after treatment. Second treatment: 3-4 weeks after treatment. Third treatment: when the sorghum heads emerge. Fourth treatment: yield measurement before harvest.

[0103] 3.5.2 Investigation Methods: The response of sorghum to the pesticide was observed and recorded after application. If phytotoxicity occurred, the severity, timing, and recovery time were recorded. Observations were made 3 and 10 days after application. Sorghum heart leaves in all treatment areas for 30% benzoyl peroxide suspension showed slight chlorosis. Two weeks after application, except for the 54 g / ha treatment area where sorghum growth was slightly inhibited and the lower leaves remained white, the leaf color of sorghum in the other three dosage treatment areas was normal, and new leaves in all treatments were normal. Yield results showed a significant increase in yield compared to the control group in all treatment areas.

[0104] 3.6. Output and Quality

[0105]

[0106]

[0107] 3.7 Impact on other organisms

[0108] No impact on other organisms was found.

[0109] 4. Experimental Results and Analysis

[0110] Table 2 shows the control effect (number of plants %) of annual weeds in sorghum fields using 30% benzoyl sulfide suspension in Examples 1-3 - 15 days after application.

[0111] Table 2

[0112]

[0113] Table 3 shows the control effect (number of plants %) of 30% benzoxazine suspension on annual weeds in sorghum fields in Examples 1-3 - 30 days after application.

[0114] Table 3

[0115]

[0116] Table 4 shows the control effect (fresh weight %) of 30% benzoyl sulfide suspension on annual weeds in sorghum fields in Examples 1-3 - 30 days after application.

[0117] Table 4

[0118]

[0119]

[0120] 5. Conclusion

[0121] Thirty days after application, the control efficacy of 22.5, 27, 31.5, and 54 g / ha of the active ingredient in 30% benzoyl permethrin suspension in Examples 1-3 and 5 against barnyardgrass was 87.9%, 91.9%, 94.3%, and 84.2% in terms of plant number, and 89.6%, 93.4%, 96.4%, and 85.5% in terms of fresh weight, respectively. The control efficacy against the total number of annual broadleaf weeds was 92.1%, 95.8%, 98.6%, and 87.9%, and 94.9%, 97.6%, 99.4%, and 91.3%, respectively. The total control efficacy against annual weeds was 90.8%, 94.7%, 97.3%, and 86.8%, respectively, and the total fresh weight control efficacy was 93.3%, 96.4%, 98.5%, and 89.6%, respectively.

[0122] Based on the above experimental results, the 30% benzoyl permethrin suspension herbicide provided in the examples is suitable for post-emergence foliar spraying in sorghum fields. The appropriate application time is when the sorghum is at the 3-5 leaf stage, annual grass weeds are at the 2-4 leaf stage, and annual broadleaf weeds are less than 5 cm tall. It has good control efficacy against annual broadleaf weeds such as Polygonum chinense, Echinochloa crus-galli, and garland chrysanthemum in sorghum fields, and also has relatively good control efficacy against barnyard grass and lambsquarters.

[0123] Safety: Under the climatic conditions of this year (2020), sorghum leaves showed signs of chlorosis and yellowing after application of the recommended dosage, but recovered later, with new leaves growing normally, and no impact on yield. The herbicide effect was significant, and no impact on other pests, diseases, or natural enemies was found.

[0124] II. Persistent foaming property was determined according to GB / T28137-2011.

[0125] III. The dumping test shall be conducted in accordance with HG / T2467.5-2003 "Dumping Test".

[0126] IV. Wet sieve test: Performed according to GB / T16150-1995.

[0127] V. Thermal storage stability: Use a syringe to draw about 20g of suspension sample and inject it into a clean ampoule. After sealing at high temperature, place it in a constant temperature (54±2℃) incubator and store for 14 days. Then take it out and test its suspension.

[0128] VI. Cold Storage Stability: Take 80 mL of the suspension and place it in a 100 mL beaker. Keep it in a refrigerator (-5±2℃) for 1 hour, stirring once every 15 minutes for 15 seconds each time. Observe the changes in appearance. Then put the beaker back into the refrigerator and continue to place it at (-5±2℃) for 7 days. After 7 days, take it out and place it at room temperature to test its suspension rate.

[0129] Table 8 shows the results of persistent foaming, pouring, suspension rate, wet sieving test, suspension rate after hot storage, and suspension rate after cold storage.

[0130] Table 8

[0131]

[0132]

[0133] As illustrated by the above embodiments, the benzoxazine-containing suspension of the present invention has the advantages of excellent stability and long effective time of the active ingredient.

Claims

1. A suspension concentrate containing benzoxazine, characterized in that, The suspending agent comprises, by weight percentage: 30 wt% benzoxazine technical grade, 4 wt% Morwet D-425 dispersant, 2.5 wt% C13 alcohol polyoxyethylene ether, 0.1 wt% SAG1522 defoamer, 1 wt% sodium chloride, 1 wt% magnesium aluminum silicate, 0.12 wt% xanthan gum, 0.1 wt% BIT preservative, 0.1 wt% 1-butyl-3-methylimidazolium iodide, with the balance being water.

2. A method for preparing the benzoxazine suspension according to claim 1, characterized in that, The preparation method includes: homogenizing and shearing benzoxazine technical, Morwet D-425 dispersant, C13 alcohol polyoxyethylene ether, SAG1522 defoamer, sodium chloride, BIT preservative, 1-butyl-3-methylimidazolium iodide and water at 2000 rpm for 30 min; grinding the dispersion to a particle size of 325 mesh to obtain the first grinding material; taking half the mass of the first grinding material and grinding it a second time to a particle size of 800 mesh to obtain the second grinding material; mixing the first grinding material and the second grinding material to obtain the grinding material; adding magnesium aluminum silicate and xanthan gum to the grinding material and homogenizing and shearing at 2000 rpm for 30 min to obtain a suspension containing 30% benzoxazine.

3. The application of the benzoxazine suspension concentrate according to claim 1 in the control of grass and broadleaf weeds in sorghum fields.

4. The application according to claim 3, characterized in that, The application is used when sorghum is in the 3-5 leaf stage.

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