A diflufenicol / acetochlor dispersible oil suspension and preparation method thereof

Abstract

The present application relates to the technical field of herbicides, and specifically discloses a difluanid-acetochlor dispersible oil suspension and a preparation method thereof. The suspension comprises the following raw materials in percentage by mass: difluanid 2% to 6%, acetochlor 30% to 40%, emulsifier 8% to 15%, wetting agent 1% to 4%, suspending agent 1% to 5%, degrading agent 0.2% to 1%, and oily filler supplemented to 100%; the degrading agent is a mixture of cyclodextrin, nitrite and thiosulfate in a mass ratio of (10 to 20): 1: (2 to 5). The suspension prepared by the present application has a good herbicidal effect, and the degradation rate in the soil after application is fast, so that the residual situation of the agent can be effectively improved, which is in line with the development concept of green environmental protection.

Description

Technical Field

[0001] The present application relates to the technical field of herbicides, and more specifically, to a difluanid-acetochlor dispersible oil suspension and a preparation method thereof. Background Art

[0002] As a major agricultural country, the quality of crop harvests is of vital importance to my country. With the development of science and technology, various factors that harm crops have been effectively improved, and weather, insect pests, and weeds are all major influencing factors. Among them, weed damage refers to the situation where weeds coexisting with crops occupy resources, resulting in the restriction of crop growth or even death. If weeds are not cleared in time, the weeds in the adult stage will not only occupy soil resources, but also the crops with shorter plants will even be blocked from sunlight, which will seriously affect the normal growth of crops.

[0003] At present, the more convenient way to control weeds is to use drugs, that is, spraying herbicides on weeds without affecting the growth of crops, so as to achieve the effect of weed control. Acetochlor is a selective pre-emergence herbicide, which is mainly absorbed by the coleoptiles of monocots or the hypocotyls of dicots, and then conducts upward after absorption, inhibits cell growth by hindering protein synthesis, stops the growth of weed shoots and roots, and then dies.

[0004] Acetochlor is widely used due to its high efficiency and broad-spectrum weed control effect, but there is still a situation where weed resistance is easily enhanced due to the single drug property, which leads to a decrease in weed control effect. In view of this situation, a combination of multiple agents is generally used to overcome the above defects, but the specific compound agent and compound ratio are the difficulties of this method. In addition, the natural degradation rate of acetochlor after application is slow, and it is easy to remain in the soil or seep into the groundwater, which has a greater impact on the environment. Summary of the invention

[0005] In order to improve the herbicidal effect of the suspension concentrate and effectively overcome the defect of slow natural degradation rate of acetochlor after application, the present application provides a diflufenicol-acetochlor dispersible oil suspension concentrate and a preparation method thereof.

[0006] In the first aspect, the present application provides a difluanid / acetochlor dispersible oil suspension, which adopts the following technical solution:

[0007] A diflufenac-acetochlor dispersible oil suspension comprises the following raw materials in percentage by mass: 2%-6% of diflufenac, 30%-40% of acetochlor, 8%-15% of emulsifier, 1%-4% of wetting agent, 1%-5% of suspending agent, 0.2%-1% of degradation aid, and oily filler supplemented to 100%; the degradation aid is a mixture of cyclodextrin, nitrite and thiosulfate in a mass ratio of (10-20):1:(2-5).

[0008] By adopting the above technical scheme, the above percentage of pyrifos and acetochlor are compounded. Due to the different weeding mechanisms of the two, there is a good synergistic effect, which helps to reduce the situation that drug resistance is easily generated due to a single drug property, and has a more obvious synergistic effect on the overall herbicidal efficacy of the suspension. In addition, cyclodextrin is used as a carrier, and nitrite and thiosulfate are used as co-degradants of the active ingredient. Due to the good dispersion effect of cyclodextrin in the oil phase, the active ingredient can be well dispersed in the system, thereby helping to reduce the phenomenon of active ingredient sedimentation or stratification with the system, that is, the addition of the co-degradant has a small negative effect on the efficacy of the suspension. At the same time, since nitrite will have a certain content of nitrite after application, on the basis of controlling the amount of nitrite added, the photodegradation rate of acetochlor can be effectively increased. And nitrite has no obvious negative effect on crops and soil, and finally fertilizes the soil in the form of nitrogen. Moreover, the thiosulfate ionized by thiosulfate after application can accelerate the dechlorination rate of setochlor. After the dechlorination of setochlor, the natural photolysis rate of setochlor is accelerated, thereby effectively improving the natural degradation rate of setochlor.

[0009] Since nitrite and thiosulfate have different mechanisms for promoting the degradation of acetochlor, the two cooperate with each other to further improve the photodegradation rate of acetochlor. At the same time, since the base phase of the suspension is an oil phase formed by an oily filler, nitrite and thiosulfate have good stability in the system, that is, the two are basically not ionized in the system, so the effect of the two on the natural degradation of acetochlor in the system before application is weak, thereby making the acetochlor in the suspension before application relatively stable.

[0010] After application, due to the strong complexing effect of cyclodextrin on acetochlor, acetochlor tends to be loaded on cyclodextrin and interact with weeds, and at the same time, the nitrite and thiosulfate loaded on cyclodextrin gradually react with acetochlor to promote the degradation of acetochlor. Therefore, the presence of cyclodextrin can also promote the contact between nitrite and thiosulfate and acetochlor, thereby further increasing the degradation rate of acetochlor after application.

[0011] Preferably, the raw materials include the following percentages by mass: 4% to 5% of difluanid, 35% to 38% of sethoxydim, 10% to 13% of emulsifier, 2% to 3% of wetting agent, 2% to 4% of suspending agent, 0.5% to 1% of degradation aid, and the oily filler is supplemented to 100%; the degradation aid is a mixture of cyclodextrin, nitrite and thiosulfate in a mass ratio of (15 to 18):1:(3 to 4).

[0012] By adopting the above technical solution, the ratio of each component of the suspension concentrate is further optimized, which has a positive significance on the efficacy of the suspension concentrate and the degradation rate of sethoxydim.

[0013] Preferably, the emulsifier is a mixture of polyoxyalkylene castor oil, polyoxyethylene sorbitan monooleate and tristyrylphenol polyoxyethylene ether in a mass ratio of (3-6):1:1.

[0014] By adopting the above technical scheme, polyoxyalkylene castor oil, polyoxyethylene sorbitan monooleate and tristyrylphenol polyoxyethylene ether are mixed in a mass ratio of (3-6):1:1 as emulsifiers, a better emulsification effect can be obtained, thereby making the dispersion effect of difluanid and setochlor in the system better.

[0015] Preferably, the wetting agent includes at least one of dialkyl sulfonyl succinate sodium salt, sodium lauryl sulfate, alkyl naphthalene sulfonate, alkylphenol formaldehyde resin polyoxyethylene ether, and fatty alcohol sulfate.

[0016] By adopting the above technical solution, the above specific substances can be added into the system as wetting agents to obtain a good wetting effect, which is helpful to improve the weed control efficiency of difluanid and setochlor after application.

[0017] Preferably, the suspending agent is a mixture of organic bentonite and white carbon black in a mass ratio of 1:(2-5).

[0018] By adopting the above technical solution, since both the organic bentonite and white carbon black have a large surface area and a high adsorption capacity and are easy to suspend, the suspension rate of the system can be effectively improved.

[0019] Preferably, the oily filler includes at least one of methyl oleate, methyl benzoate and dimethyl phthalate.

[0020] Preferably, the preparation method of the pro-degradant comprises the following steps:

[0021] Predissolution: add cyclodextrin into water at 40℃~50℃, mix and stir to obtain a mixture for use;

[0022] Blending: adding nitrite and thiosulfate into the mixture and continuing to stir to obtain a wet material of the pro-degradant;

[0023] Drying: Dry the wet material of the degradant to obtain dry material of the degradant, and then crush the dry material of the degradant to obtain the finished product of the degradant.

[0024] By adopting the above technical solution, nitrite and thiosulfate are added and blended after cyclodextrin is pre-dissolved, so that nitrite and thiosulfate can be well loaded on cyclodextrin. After drying the wet material of the degrading agent, nitrite and thiosulfate can be relatively stably loaded on cyclodextrin. Then the dry material is crushed to obtain a degrading agent with a smaller particle size, which helps to improve the dispersion effect of the degrading agent in the suspension system.

[0025] Preferably, the particle size of the degradation aid is 1 to 5 μm.

[0026] By adopting the above technical solution, the degradation aid with a particle size of 1 to 5 μm has a better dispersion effect in the suspension system and is not prone to agglomeration.

[0027] In a second aspect, the present application provides a method for preparing a diflufenicol / acetochlor dispersible oil suspension, which adopts the following technical solution.

[0028] A method for preparing a diflufenicol-acetochlor dispersible oil suspension comprises the following steps:

[0029] The difluanid, acetochlor, emulsifier, wetting agent, suspending agent, degradation aid and oily filler are mixed and stirred to obtain a mixture, and the mixture is sand-milled to obtain a finished suspension concentrate.

[0030] In summary, this application has the following beneficial effects:

[0031] 1. The present application uses cyclodextrin as a carrier, and loads nitrite and thiosulfate on cyclodextrin, so that the obtained degradation aid can be well dispersed in the suspension system; after application, nitrite and thiosulfate are ionized to produce nitrite and thiosulfate, wherein nitrite can effectively increase the degradation rate of acetochlor after reacting with acetochlor, and thiosulfate can effectively promote the dechlorination reaction of acetochlor after reacting with acetochlor, and the photodegradation rate of acetochlor after dechlorination is significantly improved, thereby achieving the effect of increasing the degradation rate of acetochlor; in addition, since the base phase of the suspension is an oil phase, that is, nitrite and thiosulfate are basically not ionized in the system, so that the acetochlor in the system before application can exist relatively stably, that is, the natural degradation rate of acetochlor before application is relatively slow.

[0032] 2. The present application uses cyclodextrin as a carrier of nitrite and thiosulfate, so that nitrite and thiosulfate can be better dispersed in the system. At the same time, after application, due to the strong complexation of cyclodextrin on setochlor, it helps to increase the contact rate between setochlor and nitrite and thiosulfate, promote interaction, and thus further increase the natural degradation rate of setochlor.

[0033] 3. The present application uses diflufenicol and acetochlor in combination and limits the ratio between the two. The prepared suspension has a good herbicidal effect and can effectively reduce the occurrence of weed resistance.

[0034] 4. The present application controls the particle size of the degradation aid to be 1 to 5 μm, thereby improving the dispersion effect of the degradation aid in the system and effectively reducing the agglomeration phenomenon. DETAILED DESCRIPTION

[0035] The present embodiment provides a diflufenicol / acetochlor dispersible oil suspension, comprising the following raw materials in percentage by mass: 2% to 6% of diflufenicol, 30% to 40% of acetochlor, 8% to 15% of emulsifier, 1% to 4% of wetting agent, 1% to 5% of suspending agent, 0.2% to 1% of degradation aid, and oily filler to 100%; the degradation aid is a mixture of cyclodextrin, nitrite and thiosulfate in a mass ratio of (10 to 20):1:(2 to 5).

[0036] The distribution ratio of each component in this embodiment is further optimized as follows: diflufenicol 4% to 5%, sethoxydim 35% to 38%, emulsifier 10% to 13%, wetting agent 2% to 3%, suspending agent 2% to 4%, degradation aid 0.5% to 1%, and oily filler is supplemented to 100%; the degradation aid is a mixture of cyclodextrin, nitrite and thiosulfate in a mass ratio of (15 to 18):1:(3 to 4).

[0037] The emulsifier in this embodiment is a mixture of polyoxyalkylene castor oil, polyoxyethylene sorbitan monooleate and tristyrylphenol polyoxyethylene ether in a mass ratio of (3-6):1:1, and a further preferred mass ratio is (4-5):1:1.

[0038] The wetting agent in this embodiment includes at least one of dialkyl sulfonyl succinate sodium salt, sodium lauryl sulfate, alkyl naphthalene sulfonate, alkylphenol formaldehyde resin polyoxyethylene ether, and fatty alcohol sulfate. The more preferred wetting agent is dialkyl sulfonyl succinate sodium salt.

[0039] The suspending agent in this embodiment is a mixture of organic bentonite and white carbon in a mass ratio of 1:(2-5), and a further preferred mass ratio is 1:(2-3).

[0040] The oily filler in this embodiment includes at least one of methyl oleate, methyl benzoate, and dimethyl phthalate, and a further preferred oily filler is methyl oleate.

[0041] The preparation method of the pro-degradation agent in this embodiment comprises the following steps:

[0042] Predissolution: add cyclodextrin into water at 40℃~50℃, mix and stir to obtain a mixture for use;

[0043] Blending: adding nitrite and thiosulfate into the mixture and continuing to stir to obtain a wet material of the pro-degradant;

[0044] Drying: Drying the co-degradant wet material to obtain the co-degradant dry material, and then crushing the co-degradant dry material to obtain the finished co-degradant; and the preferred particle size of the finished co-degradant is 1 to 5 μm.

[0045] The present application is further described in detail below in combination with preparation examples, embodiments and comparative examples. The raw materials involved in the present application can be obtained from the market, among which the CAS number of polyoxyalkylene castor oil is 61791-12-6;

[0046] The CAS number of polyoxyethylene sorbitan monooleate is 9005-65-6;

[0047] The CAS number of tristyrylphenol polyoxyethylene ether is 99734-09-5.

[0048] Preparation example of prodegradant

[0049] Preparation Example 1

[0050] A pro-degradation agent, comprising the following raw materials by weight: 17 kg of cyclodextrin, 1 kg of nitrite, and 3 kg of thiosulfate;

[0051] The nitrite is sodium nitrite;

[0052] Thiosulfate is sodium thiosulfate;

[0053] The cyclodextrin is beta-cyclodextrin.

[0054] The preparation method of the pro-degradation agent comprises the following steps:

[0055] A1 pre-dissolution: add cyclodextrin into 10L deionized water at 50°C, mix and stir for 5min at a stirring speed of 600rpm to obtain a mixture for use;

[0056] A2 blending: Keep the stirring speed unchanged, add nitrite and thiosulfate into the mixture and continue stirring for 10 minutes to obtain a wet material of the pro-degradant;

[0057] A3 Drying: Filter the wet material of the degradation agent, and dry the filter residue at 90°C to obtain dry material of the degradation agent, and then crush the dry material of the degradation agent to a particle size of 1 to 5 μm to obtain a finished degradation agent.

[0058] Preparation Example 2

[0059] The difference between this preparation example and preparation example 1 is that the ratio of the raw materials is different, specifically as follows: 10 kg of cyclodextrin, 1 kg of nitrite, and 2 kg of thiosulfate.

[0060] Preparation Example 3

[0061] The difference between this preparation example and preparation example 1 is that the ratio of the raw materials is different, specifically as follows: 10 kg of cyclodextrin, 1 kg of nitrite, and 5 kg of thiosulfate.

[0062] Preparation Example 4

[0063] The difference between this preparation example and preparation example 1 is that the ratio of the raw materials is different, specifically as follows: 20 kg of cyclodextrin, 1 kg of nitrite, and 2 kg of thiosulfate.

[0064] Preparation Example 5

[0065] The difference between this preparation example and preparation example 1 is that the ratio of the raw materials is different, specifically as follows: 20 kg of cyclodextrin, 1 kg of nitrite, and 5 kg of thiosulfate.

[0066] Preparation Example 6

[0067] The difference between this preparation example and preparation example 1 is that the ratio of the raw materials is different, specifically as follows: 15 kg of cyclodextrin, 1 kg of nitrite, and 4 kg of thiosulfate.

[0068] Preparation Example 7

[0069] The difference between this preparation example and preparation example 1 is that in the A3 drying step, the particle size of the degradation aid obtained is 20 to 30 μm.

[0070] Comparative Preparation Example

[0071] Comparative Preparation Example 1

[0072] The difference between this comparative preparation example and preparation example 1 is that nitrite is not added, but an equal amount of thiosulfate is used to make up the difference.

[0073] Comparative Preparation Example 2

[0074] The difference between this comparative preparation example and preparation example 1 is that thiosulfate is not added, but an equal amount of nitrite is used to make up for it.

[0075] Comparative Preparation Example 3

[0076] The difference between this comparative preparation example and preparation example 1 is that an equal amount of chitosan is used to replace cyclodextrin.

[0077] Example

[0078] Embodiments 1 to 5

[0079] The following description is given by taking Example 1 as an example.

[0080] Example 1

[0081] A difluanid / acetochlor dispersible oil suspension, comprising the following raw materials in weight: 4 kg difluanid, 36 kg acetochlor, 12 kg emulsifier, 2 kg wetting agent, 3 kg suspending agent, 0.8 kg degradation aid, and 42.2 kg oily filler;

[0082] The degradation aid is prepared in Preparation Example 1;

[0083] The emulsifier is a mixture of polyoxyalkylene castor oil, polyoxyethylene sorbitan monooleate and tristyrylphenol polyoxyethylene ether in a mass ratio of 4:1:1;

[0084] The wetting agent is sodium dialkyl sulfonyl succinate;

[0085] The suspending agent is a mixture of organic bentonite SK-04 and white carbon black in a mass ratio of 1:2;

[0086] The oily filler is methyl oleate.

[0087] The preparation method of the difluanid-acetochlor dispersible oil suspension comprises the following steps:

[0088] S1: mixing: mixing and stirring diflufenicol, acetochlor, an emulsifier, a wetting agent, a suspending agent, a degradation aid and an oily filler to obtain a mixture;

[0089] S2 Sand grinding: Sand grind the mixture for 3 hours, and the wet sieve passing rate of 1000 mesh sieve is ≥99% to obtain the finished suspension.

[0090] As shown in Table 1, the difference between Examples 1 to 5 is mainly in the different raw material ratios.

[0091] Table 1 Raw material ratio table

[0092]

[0093] As shown in Table 2, the main difference between Examples 6 to 13 is the different ratios of difluanid and acetochlor in the raw materials, and the balance is supplemented to 100 kg with oily filler.

[0094] Table 2 Ratio of difluanid and acetochlor

[0095]

[0096] Embodiment 14

[0097] The difference between this embodiment and embodiment 1 is that the degradation aid is prepared in preparation example 2.

[0098] Embodiment 15

[0099] The difference between this embodiment and embodiment 1 is that the degradation aid is prepared in preparation example 3.

[0100] Example 16

[0101] The difference between this embodiment and embodiment 1 is that the degradation aid is prepared in preparation example 4.

[0102] Embodiment 17

[0103] The difference between this embodiment and embodiment 1 is that the degradation aid is prepared in preparation example 5.

[0104] Embodiment 18

[0105] The difference between this embodiment and embodiment 1 is that the degradation aid is prepared in Preparation Example 6.

[0106] Embodiment 19

[0107] The difference between this embodiment and embodiment 1 is that the degradation aid is prepared in Preparation Example 7.

[0108] Embodiment 20

[0109] The difference between this embodiment and embodiment 1 is that the emulsifier is a mixture of polyoxyalkylene castor oil, polyoxyethylene sorbitan monooleate and tristyrylphenol polyoxyethylene ether in a mass ratio of 3:1:1.

[0110] Embodiment 21

[0111] The difference between this embodiment and embodiment 1 is that the emulsifier is a mixture of polyoxyalkylene castor oil, polyoxyethylene sorbitan monooleate and tristyrylphenol polyoxyethylene ether in a mass ratio of 6:1:1.

[0112] Embodiment 22

[0113] The difference between this embodiment and embodiment 1 is that the suspending agent is a mixture of organic bentonite and white carbon black in a mass ratio of 1:5.

[0114] Embodiment 23

[0115] The difference between this embodiment and embodiment 1 is that the suspending agent is a mixture of organic bentonite and white carbon black in a mass ratio of 1:4.

[0116] Comparative Example

[0117] Comparative Example 1

[0118] The difference between this comparative example and Example 1 is that the degradation aid is prepared by Comparative Preparation Example 1.

[0119] Comparative Example 2

[0120] The difference between this comparative example and Example 1 is that the degradation aid is prepared by Comparative Preparation Example 2.

[0121] Comparative Example 3

[0122] The difference between this comparative example and Example 1 is that the degradation aid is prepared according to Comparative Preparation Example 3.

[0123] Comparative Example 4

[0124] The difference between this comparative example and Example 1 is that no degradation aid is added.

[0125] Comparative Example 5

[0126] The difference between this comparative example and Example 1 is that no degradation aid is added, and equal amounts of sodium nitrite and sodium thiosulfate are used to make up the difference, and the mass ratio of nitrite to thiosulfate is 1:3.

[0127] Comparative Example 6

[0128] The difference between this comparative example and Example 1 is that the degradation aid is replaced by an equal amount of β-cyclodextrin.

[0129] Comparative Example 7

[0130] The difference between this comparative example and Example 1 is that diflufenicol is not added, and an equal amount of acetochlor is used to make up the difference.

[0131] Comparative Example 8

[0132] The difference between this comparative example and Example 1 is that no acetochlor is added, and an equal amount of diflufenicol is used to make up the difference.

[0133] Comparative Example 9

[0134] A herbicidal pesticide composition containing ametryn and acetochlor comprises the following raw materials: 200 g of ametryn, 200 g of acetochlor, 50 g of salicylic acid, 50 g of chitosan, 20 g of dispersant NNO, 40 g of Nongru 700#, 2 g of xanthan gum, and water to make up to 1000 g.

[0135] The preparation method is as follows: after the above components are fully mixed, they are sheared at high speed, and then input into a sand mill for sand grinding to obtain a finished product.

[0136] Performance testing methods

[0137] Efficacy test: Conduct the test in accordance with (NY / T 1155.4--2006) "Guidelines for Indoor Bioassay Tests of Pesticides - Herbicides Part 4: Activity Assay Test - Stem and Leaf Spray Method";

[0138] Test subjects: Gramineae weeds, including Kentucky bluegrass, Alopecurus ovata, broadleaf weeds, and Purslane. Their seeds were provided by the Weed Laboratory of the College of Agriculture of Jiangxi Agricultural University. The weed seeds were moisturized and germinated with water at (28 ± 2)℃.

[0139] Instruments and equipment: electronic balance (sensitivity 0.1 mg), Potter spray tower (produced by Nanjing Agricultural Machinery Research Institute of the Ministry of Agriculture), XZ-1600 light incubator, pots, beakers, pipettes, etc.

[0140] (1) Reagent preparation: dilute the finished pharmaceutical preparations in Examples 1 to 23 and Comparative Examples 1 to 9 into a 750 mg / L (herbicidal active ingredient) pharmaceutical solution for use;

[0141] (2) Test materials: The test used air-dried sandy loam with an organic matter content of 2.4%, pH 5.4, good permeability, and passed through a 40-mesh sieve. The test soil was quantitatively filled to 4 / 5 of the pot (50cmX50cm), and the soil was completely moistened by infiltration irrigation at the bottom of the pot. After soaking and germination of the seeds, 60 full and uniformly germinated seeds were selected and evenly sown on the surface of the pot soil, covered with 0.5cm of soil, and the weeds were transplanted 7 days after sowing when they had one leaf and one heart, and 30 plants were kept in each pot for testing.

[0142] (3) Place the pots in a Potter spray tower and adjust the pressure to 3.0 Pa. Treat each pot with 10 mL of the solution and set clean water without the drug as a blank control. After the pesticide is applied and air-dried, move the pots to a greenhouse with natural light at (28 ± 2) °C for cultivation and replenish water by infiltration irrigation from the bottom of the pots.

[0143] Survey method: After treatment, visual observations were made regularly to record the emergence of weeds and their growth status after emergence. 14 days after treatment, the herbicidal activity was surveyed and recorded once using the absolute value (number measurement) survey method, and the damage symptoms such as dwarfing, deformity, and albinism were described at the same time. Based on the survey data, the plant control effect (corrected mortality rate) of each treatment was calculated according to the following formula, the unit is percentage (%), and the calculation result is rounded to two decimal places;

[0144] E = (CT) ÷ C × 100;

[0145] Where: E is the plant protection effect (corrected mortality); C is the survival rate of control weeds; T is the survival rate of treated weeds.

[0146] Degradation test: With reference to DB21T1546-2007 "Determination of the Residues of Acetochlor and Butachlor in Soil - Gas Chromatography", the residues of acetochlor in the soil were detected 0d, 14d and 30d after application. The agents were the finished agents in Examples 1 to 23, Comparative Examples 1 to 7 and Comparative Example 9, respectively. The soil samples were obtained by the five-point sampling method in the control effect test. The residual rate calculation formula is as follows:

[0147] Residual rate (%) = (XY) / X×100%;

[0148] Where: X is the residual amount of acetochlor in the soil 0 days after application; Y is the residual amount of acetochlor in the soil 14 days or 30 days after application.

[0149] Table 3 Test data table

[0150]

[0151]

[0152]

[0153] According to the test data in Table 3, combined with the test results of Examples 1 to 5 and Comparative Example 9, the suspension concentrate obtained by combining diflufenicol with acetochlor has a relatively excellent control effect on weeds. In addition, due to the addition of the degradation aid, the degradation rate of acetochlor in the suspension concentrate is significantly improved.

[0154] Based on the test results of Example 1, Examples 6 to 13 and Comparative Examples 7 to 8, the control effect of the combined use of diflufenicol and setochlor is significantly better than that of a single active ingredient, and the ratio between diflufenicol and setochlor has a more obvious effect on the control effect.

[0155] Combined with the test results of Example 1, Comparative Examples 1 to 3 and Comparative Examples 5 to 6, there is a synergistic effect between nitrite and thiosulfate, that is, the effect of promoting the degradation of acetochlor after application is better when the two are used in combination. And cyclodextrin, as a carrier of nitrite and thiosulfate, helps to improve the dispersibility of nitrite and thiosulfate, and can effectively reduce the interaction between nitrite, thiosulfate and acetochlor before application, thereby helping to reduce the situation of decreased efficacy due to the degradation of acetochlor before application. At the same time, excessive addition of nitrite not only has no promoting effect on the degradation of acetochlor, but will have a certain inhibitory effect.

[0156] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A diflufenicol-acetochlor dispersible oil suspension, characterized in that: The invention comprises the following raw materials in percentage by weight: difluanid 2% to 6%, acetochlor 30% to 40%, emulsifier 8% to 15%, wetting agent 1% to 4%, suspending agent 1% to 5%, degradation aid 0.2% to 1%, and oily filler to 100%; the degradation aid is a mixture of cyclodextrin, nitrite and thiosulfate in a mass ratio of (10 to 20): 1: (2 to 5); The emulsifier is a mixture of polyoxyethylene castor oil, polyoxyethylene sorbitan monooleate and tristyrylphenol polyoxyethylene ether in a mass ratio of (3-6):1:1; The suspending agent is a mixture of organic bentonite and white carbon black in a mass ratio of 1: (2-5).

2. The diflufenicol-acetochlor dispersible oil suspension according to claim 1, characterized in that: The invention comprises the following raw materials in percentage by weight: 4% to 5% of difluanid, 35% to 38% of sethoxydim, 10% to 13% of emulsifier, 2% to 3% of wetting agent, 2% to 4% of suspending agent, 0.5% to 1% of degradation aid, and oily filler to make up to 100%; the degradation aid is a mixture of cyclodextrin, nitrite and thiosulfate in a mass ratio of (15 to 18):1:(3 to 4).

3. The diflufenicol-acetochlor dispersible oil suspension according to claim 1, characterized in that: The wetting agent includes at least one of dialkyl sulfonyl succinate sodium salt, sodium lauryl sulfate, alkyl naphthalene sulfonate, alkylphenol formaldehyde resin polyoxyethylene ether, and fatty alcohol sulfate.

4. The diflufenicol-acetochlor dispersible oil suspension according to claim 1, characterized in that: The oily filler includes at least one of methyl oleate, methyl benzoate and dimethyl phthalate.

5. The diflufenicol-acetochlor dispersible oil suspension according to claim 1, characterized in that: The preparation method of the pro-degradant comprises the following steps: Predissolution: add cyclodextrin into water at 40℃~50℃, mix and stir to obtain a mixture for use; Blending: adding nitrite and thiosulfate into the mixture and continuing to stir to obtain a wet material of the pro-degradant; Drying: Dry the wet material of the degradant to obtain dry material of the degradant, and then crush the dry material of the degradant to obtain the finished product of the degradant.

6. The diflufenicol-acetochlor dispersible oil suspension according to claim 5, characterized in that: The particle size of the pro-degradation agent is 1 to 5 μm.

7. The method for preparing a diflufenicol / acetochlor dispersible oil suspension according to any one of claims 1 to 6, characterized in that: The following steps are involved: The difluanid, acetochlor, emulsifier, wetting agent, suspending agent, degradation aid and oily filler are mixed and stirred to obtain a mixture, and the mixture is sand-milled to obtain a finished suspension concentrate.

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