A herbicidal composition and its use in the control of weeds in paddy fields

Abstract

The present application belongs to the field of agricultural weeding technology, and particularly relates to a weeding composition and application thereof in preventing and removing weeds in paddy fields. The weeding composition comprises, by mass ratio, active A, active B and active C in a mass ratio of (0.1-2):(0.5-10):(1-125), wherein the active A is oxaziclomefone, the active B is selected from bensulfuron-methyl and / or pyrazosulfuron-ethyl, and the active C is selected from propachlor and / or butachlor. The composition of the present application is used in the closure of water-seeded rice fields, and has a significant synergistic effect on common weeds in water-seeded rice fields compared with each single agent and conventional compounding schemes of propachlor-bensulfuron-methyl and butachlor-bensulfuron-methyl, and is safe for rice.

Description

Technical Field

[0001] This invention belongs to the field of agricultural weed control technology, specifically relating to a weed control composition and its application in controlling weeds in paddy fields. Background Technology

[0002] There are many types of weeds in paddy fields. When they coexist with rice, they compete for water, fertilizer and light, thus inhibiting rice growth. In addition, too many weeds can also easily lead to rice diseases and pests, resulting in reduced rice yield or even crop failure.

[0003] In recent years, with the emergence of herbicide resistance in various weeds, the damage caused by weeds in paddy fields has become increasingly serious year by year. In particular, grass weeds such as barnyard grass and barnyard grass are facing the situation of having no usable pesticides as conventional pesticides gradually become ineffective.

[0004] Pre-emergence weed control refers to the application of herbicides before and after rice sowing to prevent weed growth. Many fields that become overgrown with weeds later in the season are largely due to insufficient attention paid to pre-emergence weed control in the early stages, resulting in large weeds and small seedlings, making it difficult to apply herbicides later.

[0005] Pre-emergence weed control significantly reduces the initial weed population in the field by treating weeds before seed germination. Compared to later foliar treatments, pre-emergence weed control is simpler, more economical, and effectively reduces management costs. Proper pre-emergence weed control also reduces the amount of chemical pesticides used, contributing to the protection of the agricultural ecosystem.

[0006] Rice cultivation mainly involves two modes: transplanting and direct seeding. Direct seeding rice is further divided into dry direct seeding and wet direct seeding. Weeds in wet direct seeding paddy fields are complex, dense, and occur over a long period. Among them, barnyard grass and barnyard grass are the most serious pests and are very difficult to control. The environment of wet direct seeding fields is very favorable for weed growth. In the early stages, the soil alternates between dry and wet conditions, the rice seedlings are sparse, and the coverage area is small, so weeds have little competition. At the same time, sufficient sunlight, temperature, water, and fertilizer provide a suitable growth environment for weeds, making the weed problem difficult to solve and seriously affecting the yield and quality of rice.

[0007] Currently, the most common herbicides used for weed control in direct-seeded rice paddies include mixtures such as pretilachlor and butachlor. These herbicides are effective against barnyard grass, broadleaf weeds, and sedges in direct-seeded rice paddies, but they have two main drawbacks: 1. Incomplete weed control. While these herbicides reduce the initial weed population in paddy fields, some weeds still emerge, especially barnyard grass. In fields with a large weed population, uncontrolled weeds can cause significant problems for later weed control. 2. Short residual effect. Pretilachlor or butachlor generally only has a residual effect of 7-10 days. Since weeds germinate in batches, many new weeds emerge after 7-10 days, putting considerable pressure on later weed control.

[0008] Oxadiazon is a common pre-emergence herbicide in rice paddies. However, a search revealed no reports of its use in combination with butachlor / pretilachlor or bensulfuron / pyrimisulfuron. Therefore, it is necessary to develop a herbicide that can significantly enhance the efficacy and prolong the duration of pre-emergence effects in rice paddies compared to existing herbicides, while ensuring its safety for rice. Summary of the Invention

[0009] The purpose of this invention is to provide a herbicidal composition and its application in controlling weeds in paddy fields.

[0010] To achieve the above objectives, the present invention adopts the following technical solution:

[0011] A herbicidal composition comprising, by mass ratio, an activity A, an activity B, and an activity C in a ratio of (0.1-2):(0.5-10):(1-125), wherein activity A is oxadiazon, activity B is selected from bensulfuron-methyl and / or pyrimisulfuron, and activity C is selected from pretilachlor and / or butachlor.

[0012] The composition comprises, by mass ratio, active A, active B, and active C in the ratio of (0.5-1):(1-5):(10-80).

[0013] An application of the herbicidal composition described herein, specifically its application in controlling weeds in direct-seeded rice paddies.

[0014] The weeds are selected from at least one of the following: grass weeds, broadleaf weeds, and sedge weeds.

[0015] The weeds are selected from at least one of the following: barnyard grass, angelica sinensis, clove knotweed, water bamboo leaf, duck tongue grass, sedge, rice sedge, and sunflower grass.

[0016] Preferably, the weed is *Echinochloa crus-galli*.

[0017] An application of the herbicidal composition, and its application in the preparation of herbicidal formulations.

[0018] A pesticide herbicide comprising the herbicidal composition thereof, wherein the herbicidal composition comprises 1-99.99% by weight of the formulation.

[0019] The herbicide contains at least one of the following: emulsifier, dispersant, wetting agent, spreading agent, stabilizer, defoamer, synergist, penetrant, adhesive, solvent, thickener, pH adjuster, antifreeze, filler, and carrier.

[0020] The herbicide formulation is selected from at least one of emulsifiable concentrates, dispersible oil suspensions, wettable powders, suspension emulsions, aqueous suspensions, water emulsions, and water-dispersible granules.

[0021] The auxiliary components may include solvents (ethoxylated castor oil, water, alcohols, ketones, solvent oils, methyl oleate), penetrants (ethylene oxide condensate of alcohols, ethylene oxide condensate of fatty alcohols, sorbitol esters, glycerin), stabilizers (sulfated hexadecanoic acid and sulfated fatty alcohol glycol ethers, alkyl aryl polyether alcohols, alkylphenol formaldehyde resin polyoxyethylene ethers, polyoxyethylene alkyl ethers, xanthan gum, magnesium aluminum silicate, sodium benzoate, organobentonite, ammonium sulfate), emulsifiers (sulfonic acid succinates, taurine derivatives and phosphate esters of alcohols or polyhydroxyethylated phenolic phosphate esters, alkyl sulfates, lauryl ether sulfates, fatty alcohol sulfates, lauryl glycol ether acetals, castor oil polyoxyethylene ethers, tristyrene-phenylphenol polyoxyethylene ether phosphate esters, calcium dodecylbenzenesulfonate, polyoxyethylene dehydrated sorbitan monooleate, sodium dodecyl sulfate), and wetting agents (sulfonic acid succinates, alkyl sulfonate salts, alkyl aryl sulfonates, octyl sulfonate, etc.). (e.g., nonylphenol), dispersants (polyacrylate, lignin sulfonate, phenol sulfonic acid or naphthalene sulfonate, polymers of ethylene oxide with aliphatic alcohols or aliphatic acids or aliphatic amines and substituted phenols, lignin sulfite waste liquid, condensates of naphthalene or naphthalene sulfonic acid with phenol and formaldehyde, sodium lignin sulfonate, naphthalene sulfonate, calcium lignin sulfonate, sodium naphthalene sulfonate formaldehyde condensate), thickeners, pH adjusters, defoamers (polyoxyethylene octyl anisole, ethoxylated isooctyl) One or a mixture of several of the following: ethers, alkylphenyl polyethylene glycol ethers, tributylphenyl polyethylene glycol ethers, tristearate phenyl polyethylene glycol ethers, polyvinyl alcohol, ethoxylated polyoxypropylene, block polyethers), antifreeze agents, carriers and fillers (fumed silica, kaolin, protein, denatured protein, polysaccharide, hydrophobically modified starch, polycarboxylate, polyoxyalkylene oxide, polyethyleneamine, polyvinylpyrrolidone and copolymers, clay, natural or synthetic silicates, silica, resins).

[0022] The adjuvants described in this invention are various adjuvants commonly used in pesticide formulations. Different schemes and variations exist depending on the circumstances, and there are no particular limitations.

[0023] Compared with the prior art, the technical solution provided by the present invention has at least the following beneficial effects or advantages: the herbicidal composition provided by the present invention, with oxadiazon, pretilachlor / butachlor, and bensulfuron / pyrimisulfuron as active ingredients, significantly enhances the efficacy against common weeds in direct-seeded rice fields compared with the use of each ingredient alone or conventional compound use, and can prolong the closed-loop effect period and delay the development of resistance. Detailed Implementation

[0024] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0025] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by other personnel without creative effort based on the embodiments of the present invention are within the scope of protection of the present invention.

[0026] Test case

[0027] Example 1: Indoor bioactivity assay of the herbicide composition against Echinochloa crus-galli and safety assessment in rice

[0028] Test weed: Echinochloa crus-galli, collected from naturally matured seeds in the field in Jiaoyan Village, Yangjian Town, Xishan District, Wuxi City, Jiangsu Province.

[0029] The rice variety tested was Zhongzao 39, an indica rice strain.

[0030] Test method: Greenhouse pot method was used. The experimental soil was special experimental soil collected from untreated plots. A measured amount of soil was filled to 3 / 4 of the height of a pot with a diameter of 9 cm and a height of 11 cm. Twenty target weeds and rice seeds were evenly sown on the surface of the soil in the pot, covered with about 1 cm of fine soil, and then placed in a greenhouse (temperature 22-28℃, humidity 97%) for cultivation. Soil spraying was carried out 3 days after sowing.

[0031] Each treatment was replicated four times, with the treatment without the herbicide serving as the control. After treatment, the plants were placed in a greenhouse for normal management, and the growth of rice and Echinochloa crus-galli were observed and recorded regularly. Fifteen days after the herbicide application, the fresh weight of the above-ground parts of Echinochloa crus-galli was weighed, and the herbicide's efficacy against weeds was evaluated by the fresh weight of the weeds.

[0032] Fresh weight efficacy (%) = (Control fresh weight - Treatment fresh weight) / Control fresh weight × 100

[0033] Evaluation method for the combined effect of two herbicides: The combined effect of herbicides is evaluated according to the Gowing method, and the formula is: E0=X+Y×(100-X) / 100, where X is the fresh weight control efficacy of the target weed when component A is used alone; Y is the fresh weight control efficacy of the target weed when component B is used alone; E0 is the theoretical fresh weight control efficacy of the target when components A and B are used together; and E is the actual fresh weight control efficacy of the target when components A and B are used together.

[0034] Evaluation method for the combined effect of three herbicides: According to the Colby method, the formula is: E0 = 100 - XYZ / (100*100), where X is the percentage of the fresh weight of the target weeds compared to the fresh weight of the control when component A is used alone; Y is the percentage of the fresh weight of the target weeds compared to the fresh weight of the control when component B is used alone; Z is the percentage of the fresh weight of the target weeds compared to the fresh weight of the control when component C is used alone; E0 is the theoretical fresh weight control efficacy of the target when components A, B, and C are used together; and E is the actual fresh weight control efficacy of the target when components A, B, and C are used alone or in combination.

[0035] Evaluation criteria: When E-E0 > 10%, it indicates a synergistic effect; when E-E0 is between ±10%, it indicates an additive effect; and when E-E0 < -10%, it indicates an antagonistic effect.

[0036] The grading standards for pesticide damage are as follows:

[0037] Level 1: The rice is growing normally and shows no signs of damage;

[0038] Level 2: Slight pesticide damage to rice, with damage less than 10%;

[0039] Level 3: Moderate pesticide damage to rice, which can recover and will not affect yield;

[0040] Level 4: Severe pesticide damage to rice, difficult to recover from, resulting in reduced yield;

[0041] Level 5: Severe pesticide damage to rice, irreversible, resulting in significant yield reduction or total crop failure.

[0042] Table 1. Results of indoor bioactivity assays of the herbicidal composition against Echinochloa crus-galli and safety assessments against rice.

[0043]

[0044]

[0045] As shown in Table 1, when the application rate of oxadiazon alone reached 3g per mu in direct-seeded rice fields, the rice suffered severe phytotoxicity and the weed control effect was not ideal. According to the research, when oxadiazon was used at a reduced dosage within a safe range and mixed with pretilachlor / butachlor and bensulfuron / pyrimisulfuron in a reasonable ratio, it had a significant synergistic effect on the control of Echinochloa crus-galli in direct-seeded rice fields compared with the individual use of each and the conventional pretilachlor / butachlor / bensulfuron. Moreover, it was safe for rice at the conventional dosage.

[0046] To better illustrate the present invention, the following embodiments will be used to further explain the content of the present invention. All percentages in the formula are weight percentages.

[0047] Example 1: 40.6% Oxazine·Propranolol·Benzyl Emulsifiable Concentrate

[0048] The formulation consists of: 0.6% oxadiazon + 36% pretilachlor + 4% bensulfuron-methyl + 4% calcium dodecylbenzenesulfonate + 6% phenylethylphenol polyoxyethylene ether + 150# solvent oil to make up the difference.

[0049] Processing procedure: Simply mix and stir the above materials until they are completely dissolved.

[0050] Example 2: 41.2% Oxadiazon·Pretilachlor·Benzylsulfuron Suspension Concentrate

[0051] The formula consists of: 1.2% oxadiazon + 36% pretilachlor + 4% bensulfuron + 1.5% block polyether + 3% sodium lignosulfonate + 2% naphthalenesulfonate + 5% glycerol + 0.2% xanthan gum + 1% magnesium aluminum silicate + 0.6% sodium benzoate + water to make up the difference.

[0052] Processing procedure: The above formula is pre-crushed according to the proportion, then added to a sand mill for grinding, and then mixed under high shear to prepare a suspension.

[0053] Example 3: Preparation of 63.6% Oxafen·Butachlor·Benzylsulfuron Suspension Emulsion

[0054] The formula consists of: 0.6% oxadiazon + 60% butachlor + 3% bensulfuron-methyl + 4% castor oil polyoxyethylene ether + 20% 150# solvent oil + 5% tristyrene-phenol polyoxyethylene ether phosphate + 5% glycerol + 0.1% xanthan gum + 1.0% magnesium aluminum silicate + 0.3% sodium benzoate + water to make up the difference.

[0055] Processing procedure: Put all raw materials into a mixing tank, stir and mix them, then pass them through a colloid mill, and then put them into a sand mill to grind them to obtain a suspension emulsion, which is then discharged and packaged.

[0056] Example 4: 64.2% Oxafen·Butachlor·Benzylsulfuron-methyl Dispersible Oil Suspension

[0057] The formula consists of: 1.2% oxadiazon + 60% butachlor + 3% bensulfuron-methyl + 4% calcium dodecylbenzenesulfonate + 2% polyoxyethylene sorbitan monooleate + 9% castor oil polyoxyethylene ether + 0.6% organobentonite + 2% silica + methyl oleate to make up the difference.

[0058] Processing procedure: Mix the above raw materials in proportion, disperse them evenly by high-speed shearing, and then grind them in a sand mill to obtain a suspension.

[0059] Example 5: Preparation of 38.6% Oxadiazon·Pretilachlor·Pyrimisulfuron Water Dispersible Granules

[0060] The formula consists of: 0.6% oxadiazon + 36% pretilachlor + 2% pyrimisulfuron + 3% sodium dodecyl sulfate + 5% calcium lignosulfonate + 3% sodium naphthalenesulfonate formaldehyde condensate + 5% silica + ammonium sulfate to make up the difference.

[0061] Processing procedure: The above formula is dry-pulverized, granulated, dried, and sieved according to the specified proportions.

[0062] The granular agent was prepared.

[0063] Example 6: Preparation of 39.2% Oxadiazon·Pretilachlor·Pyrimisulfuron wettable powder

[0064] The formula consists of: 1.2% oxadiazon + 36% pretilachlor + 2% pyrimisulfuron + 1.5% sodium dodecyl sulfate + 4% sodium lignosulfonate + 2% sodium naphthalenesulfonate formaldehyde condensate + 6% silica + kaolin to make up the difference.

[0065] Processing procedure: After coarsely crushing the above formula according to the proportion, it is mixed evenly in a mixer, and then pulverized by air jet to obtain wettable powder.

[0066] Example 7: 62.6% Oxafen·Butachlor·Pyrimisulfuron EC

[0067] The formulation consists of: 0.6% oxadiazon + 60% butachlor + 2% pyrimisulfuron + 4% calcium dodecylbenzenesulfonate + 6% phenylethylphenol polyoxyethylene ether + 150# solvent oil to make up the difference.

[0068] Processing procedure: Simply mix and stir the above materials until they are completely dissolved.

[0069] Example 8: 63.2% Oxafen·Butachlor·Pyrimisulfuron Suspension Concentrate

[0070] The formula consists of: 1.2% oxadiazon + 60% butachlor + 2% pyrimisulfuron + 1.5% block polyether + 3% sodium lignosulfonate + 2% naphthalenesulfonate + 5% glycerin + 0.2% xanthan gum + 1% magnesium aluminum silicate + 0.6% sodium benzoate + water to make up the difference.

[0071] Processing procedure: The above formula is pre-crushed according to the proportion, then added to a sand mill for grinding, and then mixed under high shear to prepare a suspension.

[0072] Comparative Example 1: 0.6% Oxadiazon suspension

[0073] The formula consists of: 10% oxadiazon + 1.5% block polyether + 3% sodium lignosulfonate + 2% naphthalenesulfonate + 5% glycerol + 0.2% xanthan gum + 1% magnesium aluminum silicate + 0.6% sodium benzoate + water to make up the difference.

[0074] Processing procedure: The above formula is pre-crushed according to the proportion, then added to a sand mill for grinding, and then mixed under high shear to prepare a suspension.

[0075] Comparative Example 2: 36% Pretilachlor EC

[0076] The formula consists of: 36% propachlor + 4% calcium dodecylbenzenesulfonate + 6% phenylethylphenol polyoxyethylene ether + 150# solvent oil for replenishment.

[0077] Processing procedure: Simply mix and stir the above materials until they are completely dissolved.

[0078] Comparative Example 3: 60% Butachlor EC

[0079] The formula consists of: 60% butachlor + 4% calcium dodecylbenzenesulfonate + 6% phenylethylphenol polyoxyethylene ether + 150# solvent oil for replenishment.

[0080] Processing procedure: Simply mix and stir the above materials until they are completely dissolved.

[0081] Comparative Example 4: 4% bensulfuron-methyl wettable powder

[0082] The formula consists of: 4% benzylsulfuron + 1.5% sodium dodecyl sulfate + 4% sodium lignosulfonate + 2% sodium naphthalenesulfonate formaldehyde condensate + 6% silica + kaolin to make up the difference.

[0083] Processing procedure: After coarsely crushing the above formula according to the proportion, it is mixed evenly in a mixer, and then pulverized by air jet to obtain wettable powder.

[0084] Comparative Example 5:2% Pyrimisulfuron Dispersible Oil Suspension

[0085] The formula consists of: 2% pyrimisulfuron + 4% calcium dodecylbenzenesulfonate + 2% polyoxyethylene sorbitan monooleate + 9% castor oil polyoxyethylene ether + 0.6% organobentonite + 2% silica + methyl oleate to make up the difference.

[0086] Processing procedure: Mix the above raw materials in proportion, disperse them evenly by high-speed shearing, and then grind them in a sand mill to obtain a suspension.

[0087] Comparative Example 6: 40% Pretilachlor·Benzylsulfuron-methyl Dispersible Oil Suspension

[0088] The formula consists of: 36% propachlor + 4% bensulfuron-methyl + 4% calcium dodecylbenzenesulfonate + 2% polyoxyethylene sorbitan monooleate + 9% castor oil polyoxyethylene ether + 0.6% organobentonite + 2% silica + methyl oleate to make up the difference.

[0089] Processing procedure: Mix the above raw materials in proportion, disperse them evenly by high-speed shearing, and then grind them in a sand mill to obtain a suspension.

[0090] Comparative Example 7: 63% Butachlor·Benzylsulfuron-methyl Dispersible Oil Suspension

[0091] The formula consists of: 60% butachlor + 3% bensulfuron-methyl + 4% calcium dodecylbenzenesulfonate + 2% polyoxyethylene sorbitan monooleate + 9% castor oil polyoxyethylene ether + 0.6% organobentonite + 2% silica + methyl oleate to make up the difference.

[0092] Processing procedure: Mix the above raw materials in proportion, disperse them evenly by high-speed shearing, and then grind them in a sand mill to obtain a suspension.

[0093] Application examples

[0094] This experiment was conducted at the experimental base in Gelin Village, Jishan Town, Nanling County, Wuhu City, Anhui Province. The main weeds in the rice paddies included *Echinochloa crus-galli*, *Cyperus difformis*, and *Polygonum hydropiper*.

[0095] Test rice: Nanlingzao 2, an indica rice variety.

[0096] Application method: Sixteen pesticide treatments and one blank control were set up, with four replicates. Each plot was 50 square meters in size and randomly arranged. The soil was kept fully moist but not waterlogged before rice sowing. Soil spraying was carried out using a sprayer three days after rice sowing.

[0097] After the surface soil in the field dries, promptly apply a light watering. When the rice seedlings reach the 1-leaf-1-heart stage to the 2-leaf-1-heart stage, maintain a shallow water layer of 3-5 cm, ensuring the rice seedling heart is not submerged. Investigate the plant control efficacy against weeds and the safety to rice 20 days after application (see Table 2).

[0098] 2. Field efficacy determination of compound herbicides against weeds in direct-seeded rice fields and safety assessment of rice.

[0099]

[0100]

[0101] As shown in Table 2, in direct-seeded rice fields, the combination of oxadiazon, pretilachlor / butachlor, and bensulfuron / pyrimisulfuron exhibits higher control efficacy against Echinochloa crus-galli, Cyperus difformis, and Polygonum hydropiper compared to individual agents and the conventional pretilachlor / butachlor combination. Conventional agents generally have a residual effect of 7-10 days, resulting in generally poor control efficacy in the later stages. Twenty days after application, this combination still maintains excellent control efficacy, extending the residual effect compared to conventional agents, and also demonstrating good safety for direct-seeded rice.

Claims

1. A herbicidal composition, characterized in that: The herbicidal composition comprises, by mass ratio, active A, active B, and active C in the form of (0.1-2):(0.5-10):(1-125), wherein active A is oxadiazon, active B is selected from bensulfuron-methyl and / or pyrimisulfuron, and active C is selected from pretilachlor and / or butachlor.

2. The herbicidal composition according to claim 1, characterized in that: The composition comprises, by mass ratio, active A, active B, and active C in the ratio of (0.5-1):(1-5):(10-80).

3. The application of the herbicidal composition according to claim 1, characterized in that: Application of herbicidal composition in controlling weeds in direct-seeded rice fields.

4. The application of the herbicidal composition according to claim 3, characterized in that: The weeds are selected from at least one of the following: grass weeds, broadleaf weeds, and sedge weeds.

5. The application of the herbicidal composition according to claim 4, characterized in that: The weeds are selected from at least one of the following: barnyard grass, angelica sinensis, clove knotweed, water bamboo leaf, duck tongue grass, sedge, rice sedge, and sunflower grass.

6. The application of the herbicidal composition according to claim 1, characterized in that: The application of the herbicidal composition in the preparation of herbicidal formulations.

7. A pesticide herbicide, characterized in that, The herbicide contains the herbicidal composition of claim 1. The herbicidal composition comprises 1-99.99% by weight of the formulation.

8. The pesticide herbicide according to claim 7, characterized in that, The herbicide contains at least one of the following: emulsifier, dispersant, wetting agent, spreading agent, stabilizer, defoamer, synergist, penetrant, adhesive, solvent, thickener, pH adjuster, antifreeze, filler, and carrier.

9. The pesticide herbicide according to claim 8, characterized in that, The herbicide formulation is selected from at least one of emulsifiable concentrates, dispersible oil suspensions, wettable powders, suspension emulsions, aqueous suspensions, water emulsions, and water-dispersible granules.

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