Pesticide composition containing propanil and metamifop as well as preparation and application thereof

Abstract

The invention relates to the technical field of pesticide herbicides, in particular to a pesticide composition containing propanil and metamifop as well as a preparation and application of the pesticide composition, and the mass ratio of the propanil to the metamifop is (4.3-17): 1. A compound system of propanil and metamifop is selected, metamifop and propanil are mixed to achieve a good control effect on barnyard grass and moleplant seeds, compared with a single agent, the control effect is improved, and a certain synergistic trend is shown; three emulsifiers are mixed, 0.4-0.7 wt% of the pH regulator is added, the problem that a traditional missible oil formula is high in heat storage decomposition rate is solved, meanwhile, the pesticide preparation has the good effect of preventing and controlling annual gramineous weeds in the direct seeding rice field, and the pesticide preparation is of great benefit to planting and production of rice.

Description

Technical Field

[0001] The present invention relates to the technical field of pesticide herbicides, and in particular to a pesticide composition containing propanil and metamifop, and a preparation and application thereof. Background Art

[0002] In agricultural production, effective weed control is crucial for ensuring crop yield and quality. As a vital agricultural growing area, rice paddies face the challenge of a diverse array of weeds with increasing resistance.

[0003] As an amide-type selective contact herbicide, diazinon has a complex mechanism of action. It not only destroys plant photosynthesis, but also inhibits respiration and oxidative phosphorylation, interferes with nucleic acid and protein synthesis, etc., causing physiological disorders in sensitive plants, accelerated water loss, and gradual leaf dryness and death. Metamifop is an acetyl-CoA carboxylase (ACCase) inhibitor with the same mechanism of action as cyhalofop-butyl. It can effectively control most annual grass weeds and is relatively safe for rice. It is mainly used in transplanted and direct-seeded rice fields.

[0004] However, existing rice field herbicides have exposed many shortcomings in practical applications. For example, Chinese patent application CN109526972A provides a herbicide composition containing barnyardgrass and oxadiazon, which is particularly effective against older barnyardgrass and can effectively solve the problem of late-stage rice field barnyardgrass. However, after barnyardgrass and oxadiazon are combined, the formulation is easily ineffective due to chemical instability and physical incompatibility, and the stability is poor. Summary of the Invention

[0005] In order to solve the problems in the prior art, the first aspect of the present invention provides a pesticide composition containing propanil and metamifop, wherein the mass ratio of propanil to metamifop is (4.3-17):1.

[0006] In one embodiment, the mass ratio of the metamifop to propanil is 1:(6-10), which can be exemplified as 1:6, 5.3:34.7, 1:6.8, 1:7, 1:8, 1:9, or 1:10.

[0007] In one embodiment, the propanil and metamifop are both from Xingnong Pharmaceutical (China) Co., Ltd., and the purities of propanil and metamifop are 98% and 95%, respectively.

[0008] The second aspect of the present invention provides a pesticide formulation, wherein the raw materials for preparation include the pesticide composition and auxiliary materials; the pesticide composition accounts for 35-45% of the total weight of the pesticide formulation, which can be 35%, 36%, 37%, 38%, 39%, or 40%.

[0009] In one embodiment, the pesticide formulation is in the form of an emulsifiable concentrate.

[0010] In one embodiment, the excipients include an emulsifier, a solvent, and a pH regulator; in terms of weight percentage, the raw materials for preparing the pesticide formulation include 35-45% pesticide composition, 16-28% emulsifier, 0.4-0.7% pH regulator, and the solvent makes up the balance.

[0011] In one embodiment, the brands of the emulsifier include one or more of SP-3850, SP-EC3507, and SP-EC3530C.

[0012] In one embodiment, the brands of the emulsifier are SP-3850, SP-EC3507 and SP-EC3530C.

[0013] The SP-3850, SP-EC3507 and SP-EC3530C are all from Jiangsu Qingyu Chemical Technology Co., Ltd.

[0014] In one embodiment, the mass ratio of SP-3850, SP-EC3507 and SP-EC3530C is 1:1.5:1.5.

[0015] In one embodiment, the solvent comprises isophorone.

[0016] In one embodiment, the solvent further comprises mineral oil.

[0017] In one embodiment, the mass ratio of isophorone to solvent oil is (15-32): (0-30).

[0018] In one embodiment, the mass ratio of isophorone to solvent oil is (15-31.3):(0-28.6), which can be exemplified as 15:28.6, 20:19.5, 25:10.4, or 31.3:0.

[0019] In one embodiment, the solvent oil is No. 150 solvent oil.

[0020] In one embodiment, the pH adjuster comprises triethanolamine.

[0021] In one embodiment, the method for preparing the pesticide formulation comprises the following steps:

[0022] 85.47 wt % of solvent was added to the mixing kettle and stirring was started. Propanil, metamifop, emulsifier and the remaining solvent were added in sequence and stirred continuously for 1-1.5 h. A pH regulator was added to adjust the pH to 6-7 to obtain the pesticide preparation.

[0023] A third aspect of the present invention provides an application of a pesticide formulation for controlling annual grass weeds in direct-seeded rice fields.

[0024] Beneficial effects

[0025] 1. The application uses a compound system of propanil and oxadiazon. The mixture of oxadiazon and propanil has a good control effect on barnyard grass and Leptochloa chinensis. Compared with a single agent, the control effect is improved, showing a certain synergistic trend.

[0026] 2. This application mixes three emulsifiers, SP-3850, SP-EC3507, and SP-EC3530C, in a ratio of 1:1.5:1.5 to form a stable emulsified system. The fatty chains and polyether chains in the system are combined through hydrophobic interactions and hydrogen bonds to form composite micelles. This micelle structure wraps the active ingredients propanil and oxadiazon in the core, reducing direct contact with water molecules, inhibiting hydrolysis reactions, and significantly improving the thermal storage stability of the emulsifiable concentrate.

[0027] 3. This application solves the problem of high thermal storage decomposition rate of traditional emulsifiable concentrate formulas by adding 0.4-0.7wt% of pH regulator to adjust the system pH to between 7.0 and 8.0. The neutral to weakly alkaline environment suppresses protonation and stabilizes the molecular structure.

[0028] 4. The pesticide preparation provided by the present invention has a good effect in controlling annual grass weeds in direct-seeded rice fields, which is of great benefit to rice planting and production. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is further described in detail below with reference to the examples. It should be understood that the specific examples described herein are only used to explain the present invention and are not intended to limit the present invention. The experimental methods in the examples where specific conditions are not specified are carried out according to conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used where the manufacturer is not specified are conventional products that can be purchased commercially.

[0030] Example 1

[0031] In a first aspect, the present embodiment provides a pesticide composition containing propanil and metamifop, wherein the mass ratio of propanil to metamifop is 34.7:5.3.

[0032] The propanil and metamifop are both from Xingnong Pharmaceutical (China) Co., Ltd., and the purities of propanil and metamifop are 98% and 95% respectively.

[0033] The second aspect of this embodiment provides a pesticide preparation, which is in the form of an emulsifiable concentrate. The raw materials for preparing the pesticide preparation include 40% pesticide composition, 20% emulsifier, 0.5% pH regulator, and the balance is made up of solvent, based on weight percentage.

[0034] The pesticide composition is the pesticide composition provided in the first aspect of this embodiment.

[0035] The brands of the emulsifiers are SP-3850, SP-EC3507 and SP-EC3530C, and the mass ratio of SP-3850, SP-EC3507 and SP-EC3530C is 1:1.5:1.5.

[0036] The SP-3850, SP-EC3507 and SP-EC3530C are all from Jiangsu Qingyu Chemical Technology Co., Ltd.

[0037] The solvent is isophorone and No. 150 solvent oil. The mass ratio of the isophorone to the No. 150 solvent oil is 20:19.5.

[0038] The pH regulator is triethanolamine.

[0039] The preparation method of the pesticide preparation comprises the following steps:

[0040] 85.47 wt % of solvent was added to the mixing kettle and stirring was started. Propanil, metamifop, emulsifier and the remaining solvent were added in sequence and stirred continuously for 1 hour. A pH regulator was added to adjust the pH to 7.2 to obtain the pesticide preparation.

[0041] A third aspect of this embodiment provides an application of a pesticide formulation for controlling annual grass weeds in direct-seeded rice fields.

[0042] Example 2

[0043] The specific implementation of this embodiment is the same as that of Example 1, except that, based on weight percentage, the raw materials for preparing the pesticide formulation include 40% pesticide composition, 24% emulsifier, 0.6% pH regulator, and the solvent makes up the balance.

[0044] The mass ratio of isophorone to No. 150 solvent oil is 25:10.4.

[0045] Example 3

[0046] The specific implementation of this embodiment is the same as that of Example 1, except that, based on weight percentage, the raw materials for preparing the pesticide formulation include 40% pesticide composition, 16% emulsifier, 0.4% pH regulator, and the solvent makes up the balance.

[0047] The mass ratio of isophorone to No. 150 solvent oil is 15:28.6.

[0048] Example 4

[0049] The specific implementation of this embodiment is the same as that of Example 1, except that, based on weight percentage, the raw materials for preparing the pesticide formulation include 40% pesticide composition, 28% emulsifier, 0.7% pH regulator, and the balance is made up of solvent.

[0050] The solvent is isophorone.

[0051] Comparative Example 1

[0052] The specific implementation of this comparative example is the same as that of Example 1, except that, based on weight percentage, the raw materials for preparing the pesticide formulation include 40% of the pesticide composition, 12.5% ​​of the emulsifier, and the balance is made up of solvent.

[0053] The brands of the emulsifiers are SP-3850 and SP-EC3530C, and the mass ratio of SP-3850 to SP-EC3530C is 1:1.5.

[0054] The mass ratio of isophorone to No. 150 solvent oil is 20:27.5.

[0055] Comparative Example 2

[0056] The specific implementation of this comparative example is the same as that of Example 1, except that, based on weight percentage, the raw materials for preparing the pesticide formulation include 40% of the pesticide composition, 15% of the emulsifier, and the balance is made up of the solvent.

[0057] The brand of the emulsifier is EM-105N, and the EM-105N comes from Shanghai Lanheng Chemical Technology Co., Ltd.

[0058] The mass ratio of isophorone to No. 150 solvent oil is 20:25.

[0059] Comparative Example 3

[0060] The specific implementation of this comparative example is the same as that of Example 1, except that, based on weight percentage, the raw materials for preparing the pesticide formulation include 40% of the pesticide composition, 20% of the emulsifier, and the balance is made up of the solvent.

[0061] The mass ratio of isophorone to No. 150 solvent oil is 1:1.

[0062] Comparative Example 4

[0063] The specific implementation of this comparative example is the same as that of Example 1, except that, based on weight percentage, the raw materials for preparing the pesticide formulation include 40% of the pesticide composition, 20% of the emulsifier, and the balance is made up of the solvent.

[0064] The brands of the emulsifiers are EM-105N and EM162, the mass ratio of EM-105N and EM162 is 4:1, and both EM-105N and EM162 are from Shanghai Lanheng Chemical Technology Co., Ltd.

[0065] The mass ratio of isophorone to No. 150 solvent oil is 1:1.

[0066] Comparative Example 5

[0067] The specific implementation of this comparative example is the same as that of Example 1, except that, based on weight percentage, the raw materials for preparing the pesticide formulation include 40% of the pesticide composition, 20% of the emulsifier, and the balance is made up of the solvent.

[0068] The brand of the emulsifier is Ultrasurf EC050, and the Ultrasurf EC050 comes from Wuxi Yijingfeng Technology Co., Ltd.

[0069] The solvent is No. 150 solvent oil.

[0070] Performance Testing

[0071] 1. Indoor trial of a mixture of oxadixyl and propanil for controlling annual grass weeds in direct-seeded rice fields

[0072] The test targets were barnyard grass (Echinochloa crusgalli (L.) Beauv) and Leptochloachinensis (L.) Nees), whose seeds were collected from the rice experimental fields in the previous year.

[0073] Target culture: 70 × 70 × 100 mm plastic nutrient pots were filled with sterilized fine soil (4 / 5 of the pots) and placed in an enamel tray filled with water. After the soil was fully hydrated, 50 seeds of either Echinochloa crus-galli or Leptochloa chinensis were sown in each pot and covered with a thin layer of soil. After sowing, the pots were incubated in a greenhouse at 20°C-25°C, natural light, and a relative humidity of 50%-75%. The soil was kept moist for the duration of the experiment.

[0074] Instruments and equipment: ASS-4 automatic quantitative spray system (Beijing Shengheng Tianbao Technology Co., Ltd.), ME2002E electronic balance (Mettler-Toledo Instrument Co., Ltd.), pipette, beaker, etc.

[0075] Experimental Design:

[0076] Test agents: 95% oxadiazon technical and 98% propanil technical, both provided by Xingnong Pharmaceutical (China) Co., Ltd.

[0077] Dosage setting and drug preparation:

[0078] Metamifop single dose settings are 7.5, 15, 30, 60 and 120 g ai / hm 2 Five dosages: propanil single dosage settings: 127.5, 255, 510, 1020 and 2040 g ai / hm 2 Then, the five reagent amounts of metamifop and propanil were mixed into 25 treatment ratios, as shown in Table 1.

[0079] Both metamifop and propanil stock were dissolved in acetone and then prepared with a 0.1% Tween 80 aqueous solution to form a stock solution. The stock solution was diluted with a 0.1% Tween 80 aqueous solution to the test dose before application. A blank control was used with an aqueous solution containing the same solvent and emulsifier, but without the drug.

[0080] Table 1

[0081]

[0082]

[0083] Test method: Indoor potting method. The test was carried out in accordance with the agricultural industry standard of the People's Republic of China NY / T1155.9-2008 Pesticide Indoor Bioassay Test Guidelines Herbicides Part 9: Paddy Field Herbicide Activity Determination Test Stem and Leaf Spray Method and NY / T1155.7-2006 Pesticide Indoor Bioassay Test Guidelines Herbicides Part 7: Determination of Combined Action of Mixtures. The Gowing method was used to evaluate the type of combined action of the mixture. Each treatment was repeated 4 times, and a blank control was also set up. The stems and leaves of Echinochloa crus-galli and Leptochloa chinensis were sprayed at the 2-3 leaf stage. The spraying equipment was the ASS-4 automatic quantitative spray system with a fan nozzle (TeeJet 8002VS), a spray pressure of 0.275 MPa, and a spray volume of 450 L / hm2. 2 Before application, thin out weak seedlings and plant 10 seedlings per pot. Apply once. After application, place the pots in a greenhouse and keep the soil moist during the test.

[0084] Data investigation and statistical analysis:

[0085] Survey method: After spraying, regularly observe the growth of the plants. When the efficacy symptoms are obvious 21 days after application, measure the fresh weight of the aboveground parts of each weed and calculate the fresh weight control efficacy. The fresh weight control efficacy calculation formula is as follows:

[0086] Fresh weight control effect (%) = (fresh weight of weeds in blank control area - fresh weight of weeds in treatment area) / fresh weight of weeds in blank control area * 100

[0087] Data Statistical Analysis: The Gowing method was used to test the herbicide efficacy of the mixed herbicide. The formula for calculating the mixed herbicide efficacy is: E0 = X + Y – XY / 100, where X represents the weed control efficacy (based on fresh weight) at a metamifop dosage of P, and Y represents the weed control efficacy (based on fresh weight) at a propanil dosage of Q. E0 represents the theoretical control efficacy of metamifop at a dosage of P plus the theoretical control efficacy of propanil at a dosage of Q. According to the Gowing method, when E-E0 > 10%, the mixed herbicide mixture exhibits a synergistic effect; when E-E0 < -10%, it indicates an antagonistic effect; and when the E-E0 value is between ±10%, it indicates an additive effect. In the formula, E represents the measured control efficacy of (memifop + propanil) at a dosage of (P + Q). The test results are shown in Table 2.

[0088] Table 2

[0089]

[0090]

[0091] The test results show that the mixture of oxadix and propanil has a good control effect on barnyard grass and Leptochloa chinensis. Compared with single agents, the control effect is improved, showing a certain synergistic trend.

[0092] The Gowing method was used to evaluate the synergistic effect of the mixed pesticides. Table 2 shows that the difference between the actual and theoretical fresh-weight control efficacy (E-E0) of each combination of metamifenazim and propanil against Echinochloa crus-galli and Leptochloa chinensis ranged from 0.2% to 8.5%. All combinations had positive E-E0 values, indicating an additive synergistic effect.

[0093] Metamifop is more effective against Leptochloa chinensis than against Echinochloa crusgalli, while propanil is more effective against Echinochloa crusgalli than against Leptochloa chinensis. A mixture of the two has good complementarity in controlling Echinochloa crusgalli and Leptochloa chinensis. Overall, with a propanil dosage of 255-1020 g ai / hm2, the 2 +Mefenacet dosage 60g ai / hm 2 Taking into account the herbicidal effect, the type of combined action of the mixture, and the economic cost, the reasonable ratio of propanil and metamifop in the present application is 255-1020:60, that is, 4.3-17:1.

[0094] 2. Thermal storage decomposition rate test

[0095] Test samples: pesticide formulations prepared in various examples and comparative examples.

[0096] Test method: High performance liquid chromatography was used to detect the contents of propanil and oxadiazon at room temperature (25°C) and hot storage (54°C), referring to the general standard GB T 19136-2021 Pesticide Thermal Storage Stability Determination Method.

[0097] Decomposition rate calculation: (room temperature content - thermal storage content) / room temperature content * 100%. Test results are shown in Table 3-4.

[0098] Table 3

[0099]

[0100] Table 4

[0101]

[0102]

[0103] As can be seen from Tables 3 and 4, the propanil content in Comparative Examples 1-5 decreased significantly at 54°C, with decomposition rates as high as 18-34%. The content of mefenacet decreased simultaneously, with decomposition rates as high as 16-60%. The thermal storage stability of the comparative examples was significantly reduced. In contrast, the decomposition rates of the active ingredients propanil and mefenacet in the pesticide formulations prepared in the present application were both less than 2% at 54°C, demonstrating that the pesticide formulations prepared in the present application have excellent thermal storage stability.

[0104] 2. Field efficacy test

[0105] 1) Field efficacy test 1:

[0106] Location of the test site: The test site is located in the Chonggu Seed Breeding Farm of Shanghai Academy of Agricultural Sciences. The terrain is flat and the water conservancy and irrigation facilities are good.

[0107] Test target situation: The main weeds in the experimental field were barnyard grass [Echinochloa crusgalli (L.) Beauv.], duckweed [Monochoria vaginalis (Burm.f.) Presl ex Kunth], ear-based water amaranth (Ammanniaauriculata Willdenow) and difformis (Cyperus difformis L.), and the weeds in the plot were basically evenly distributed.

[0108] Trial crops, varieties and growth conditions:

[0109] Transplanted rice, variety "Songzaoxiang No. 1," was transplanted on June 26th, when the rice seedlings were 35 days old and at the 3-4 leaf stage. The transplanting density was 18,000 holes per mu. Cultivation conditions (soil type, water and fertilizer management, transplanting period, planting density, etc.) were uniform across all experimental plots and in line with local scientific agricultural practices.

[0110] Soil type of the test site:

[0111] The soil in the experimental field is bluish-purple mud with medium fertility and medium organic matter content.

[0112] Water and fertilizer management in the experimental site:

[0113] During the experiment, water and fertilizer management was carried out according to conventional production.

[0114] Meteorological data:

[0115] On the day of application, it was cloudy with winds of 2-3. The maximum temperature was 28.3°C, the minimum temperature was 23.6°C, and the average temperature was 25.7°C. Ten days before application, the maximum temperature was 35°C and the minimum temperature was 20.1°C. It rained on the 6th, 7th, 8th, 9th, and 10th days before application, with rainfall amounts of 5.1, 5.1, 2.4, 6.3, and 6.7 mm, respectively. Ten days after application, the maximum temperature reached 34.1°C on the 3rd day, and the minimum temperature reached 22.3°C on the 7th day. It rained on the 2nd, 4th, 7th, and 10th days after application, with rainfall amounts of 4.9, 1.0, 5.1, and 1.3 mm, respectively.

[0116] Information on pesticides for controlling other diseases and insect pests:

[0117] No other herbicides were used during the trial. During the rice growing season, 16% chlorfenapyr and indoxacarb SC 15 mL / mu, 25% pymetrozine SC 20 mL / mu, 0.2% chlorantraniliprole SC 10 mL / mu, and 23% oxazolidinone and epoxiconazole SC 40 mL / mu were used to control rice pests and diseases.

[0118] Experimental design and arrangement:

[0119] Plot area and repetition: Plot area 20m 2 (2m×1m), and each treatment was repeated 4 times.

[0120] Preparation of test solution:

[0121] Calculation of the amount of medicine / liquid in the cell:

[0122] One day before the test, measure 100 ml / mu of the test agent or control agent needed for each plot and place them in separate bottles. Label them for later use. Use 20 kg / mu of sand, which translates to 600 g of sand per plot.

[0123] Preparation method of the liquid medicine:

[0124] The test agent (the pesticide formulation prepared in each example) was pre-pipetted and subpackaged in the laboratory and transported to the test site at room temperature for on-site dissolution and preparation. The test agent was first dissolved in an appropriate amount of clean water, then mixed into 600 g of pre-prepared fine sand and stirred evenly.

[0125] Application:

[0126] Application method:

[0127] Mix with sand and apply by broadcasting. 2-3 days before transplanting rice, after irrigating and preparing the paddy field, while the field is muddy, apply 15-20 kg of the pesticide per mu (approximately 1 acre) of the pesticide mixed with sand and broadcast into the paddy field within a 3-5 cm water layer. Maintain a 3-5 cm deep water layer in the field for at least 7 days after transplanting to avoid submerging the heart and leaves of the rice seedlings.

[0128] Application time and frequency:

[0129] The pesticide was applied on June 7, 2021, when weeds were not yet unearthed. The pesticide was applied once during the entire experimental period. Manual weeding was performed once on the 14th day after application to remove weeds within the manually weeded plots.

[0130] Usage capacity: sand mixing amount 20 kg / mu.

[0131] Survey Methodology:

[0132] All surveys were conducted using random sampling and counting methods, i.e. 4 points were selected in each plot, with each point measuring 0.25 m 2 .

[0133] Survey time and frequency:

[0134] 28 days after application, the number of weeds remaining in the plots was surveyed by species, and the control efficacy per plant was calculated. 28 days after application, the number of weeds remaining was surveyed and the fresh weight of the remaining weeds above ground was measured, and the control efficacy per plant and fresh weight were calculated. Two surveys were conducted during the trial.

[0135] Calculation method of drug efficacy:

[0136] Control effect (%) = (CK-PT) / CK*100

[0137] Where: CK is the number of weeds or fresh weight in the control area, and PT is the number of weeds or fresh weight remaining in the treated area. The experimental results are shown in Table 5.

[0138] Table 5

[0139]

[0140] As can be seen from Table 5, the pesticide formulation prepared in the present application has the same trend in plant control efficacy and fresh weight control efficacy, and has a significant weed killing effect.

[0141] 2) Field efficacy test 2:

[0142] The experiment was conducted in an early rice paddy field at the Agricultural Science and Technology Park of Jiangxi Agricultural University in Nanchang. The field was fallow during the winter and transplanted on April 18, 2021, with a density of 13.3 cm × 30.0 cm.

[0143] Test targets: Annual weeds, mainly including barnyard grass (Echinochloa crusgalli) of the Poaceae family, duckweed (Monochoria vaginalis) of the broadleaf family, and Cyperus difformis of the Cyperaceae family. Other weeds include Paspalum distichum and Sagittaria pygmaea.

[0144] Experimental crops, varieties and growth conditions: Early rice, variety "Jinyou 402", grew well after transplanting.

[0145] Soil type of the experimental site: The soil type is red loam, with a pH value of approximately 5.0 and an organic matter content of 1.62%.

[0146] Water and fertilizer management of the experimental site: The drainage and irrigation conditions of the experimental site are good, and the management conditions of all experimental plots are consistent.

[0147] Meteorological data: The weather was overcast to cloudy when the pesticide was applied, and there was no precipitation in the 24 hours after the application. The average daily temperature during the test was 22.7°C, with a maximum of 35°C and a minimum of 15°C. No adverse weather factors were observed.

[0148] Information on pesticides for controlling other diseases and insect pests: No other pesticides were used for controlling diseases and insect pests during the trial.

[0149] Experimental design and arrangement:

[0150] Area: 30m 2 ; Number of repetitions: 4 times.

[0151] Application method:

[0152] Application period: Apply the pesticide 2 days before rice transplanting;

[0153] Usage: Poisoned soil method, mix with 15-20kg / mu of fine soil.

[0154] Application equipment: plastic bucket, etc.

[0155] Application time: Apply pesticides on April 16 (2 days before rice transplanting), transplant on April 18, maintain a 3-5 cm water layer after application until more than 7 days after rice transplanting; manual weeding is carried out once 7 days (April 25) and 30 days (May 18) after rice transplanting.

[0156] Number of applications: 1 time.

[0157] Survey time:

[0158] The number and fresh weight of weeds were investigated 40 days after rice transplanting (i.e., May 28);

[0159] Before rice harvest (i.e. July 18), the yield was measured to evaluate the production effect.

[0160] Calculation method of drug efficacy:

[0161] Control effect (%) = (CK-PT) / CK*100

[0162] Where: CK is the number or fresh weight of weeds in the control area, and PT is the number or fresh weight of weeds remaining in the treated area. The experimental results are shown in Table 6.

[0163] Table 6

[0164]

[0165] As can be seen from Table 6, the pesticide formulation prepared in the present application has the same trend in plant control efficacy and fresh weight control efficacy, and has a significant weed killing effect.

Claims

1. A pesticide composition containing propanil and metamifop, characterized in that: The mass ratio of propanil to metamifop is (4.3-17):

1.

2. The pesticide composition containing propanil and metamifop according to claim 1, characterized in that The mass ratio of propanil to metamifop is (6-10):

1.

3. A pesticide formulation, characterized in that The preparation raw materials include the pesticide composition according to any one of claims 1 to 2 and auxiliary materials; the pesticide composition accounts for 35-45% of the total weight of the pesticide preparation.

4. The pesticide formulation according to claim 3, characterized in that The dosage form of the pesticide preparation is emulsifiable concentrate.

5. The pesticide formulation according to any one of claims 3 to 4, characterized in that The auxiliary materials include emulsifiers, solvents and pH regulators; in terms of weight percentage, the raw materials for preparing the pesticide preparation include 35-45% of the pesticide composition, 16-28% of the emulsifier, 0.4-0.7% of the pH regulator, and the solvent makes up the balance.

6. The pesticide formulation according to claim 5, characterized in that The brands of the emulsifier include one or more of SP-3850, SP-EC3507, and SP-EC3530C.

7. The pesticide formulation according to claim 6, characterized in that The mass ratio of SP-3850, SP-EC3507 and SP-EC3530C is 1:1.5:1.

5.

8. The pesticide formulation according to claim 5, characterized in that The solvent includes isoflurane.

9. The pesticide formulation according to claim 5, characterized in that The pH adjuster includes triethanolamine.

10. Use of the pesticide formulation according to any one of claims 3 to 9, characterized in that: Used for the prevention and control of annual grass weeds in direct-seeded rice fields.

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