A mixed herbicidal composition containing thiencarbazone-methyl and isoproturon and its use

Abstract

The application provides a mixed herbicidal composition containing thifensulfuron-methyl and isopropyl and application thereof, and belongs to the technical field of pesticides. The thifensulfuron-methyl has good prevention effect on both grass and broadleaf weeds, and the isopropyl is used for preventing and removing annual grass weeds and part of annual broadleaf weeds. Both thifensulfuron-methyl and isopropyl have high closing and stem-leaf activity, and are safe to the next crops. The mixed herbicidal composition is prepared by binary compounding of high-efficiency components with different action mechanisms, and the two different action mechanisms are used to kill weeds, improve the prevention effect on resistant weeds, reduce the generation of weed resistance, greatly improve the weed killing activity of herbicides, can improve the prevention and treatment on various grass weeds and broadleaf weeds, and has the action of complementary weed spectrum. Therefore, the application can be applied in the prevention and treatment of grass weeds and broadleaf weeds in wheat and garlic fields, especially in the pre-emergence or early post-emergence weed control of wheat and garlic.

Description

Technical Field

[0001] This invention belongs to the field of pesticide technology, specifically relating to a mixed herbicidal composition containing thiamethoxam and isoproturon and its application. Background Technology

[0002] In recent years, influenced by the international situation, the quantity of grain imports has decreased sharply. In 2022 alone, the quantity of grain imports decreased by 10.7% year-on-year, but the amount paid increased by 10.5%. Therefore, it is necessary to increase the output of domestically produced grain to cope with the decrease in the total amount of imported grain. In my country, the annual crop yield loss caused by weeds is almost in the hundreds of millions of kilograms. Solving the weed problem is an important measure to increase grain production.

[0003] Wheat is one of my country's major grain crops, with an annual wheat planting area of ​​approximately 300 million mu (13.3 million hectares). Farmland weeds are among the harmful organisms in wheat fields, competing with wheat for sunlight, soil moisture, and nutrients, severely impacting wheat yields. Wheat weeds can reduce wheat yield by about 30%, and in severe cases, may result in total crop failure. While chemical foliar spraying of herbicides can solve some weed problems, with the extensive use of these agents, weeds have developed serious resistance, such as resistant American clover, resistant ryegrass, and resistant speedwell, gradually weakening the effectiveness of foliar weed control. Therefore, selecting highly effective herbicides that are less likely to induce resistance during the germination stage or early post-emergence period when weed growth is relatively weak can achieve more thorough control and better results.

[0004] Winter garlic, sown in the same season as wheat, has been cultivated in my country for over 2000 years, ranking first globally in both planting area and yield. Garlic fields are plagued by a wide range of adaptable and prolific weeds, with most weeds having a reproduction coefficient several to dozens of times higher than the planted crop. Weed infestations can reduce garlic yields by 20% to 30%, and in severe cases, by more than 50%. Mulching garlic helps retain water and heat, resulting in higher yields, and has gradually become the mainstream cultivation method. However, this method also makes weed control increasingly difficult and limits weed control in garlic fields to primarily soil-based weed control. Long-term use of the same herbicides has led to a gradual increase in resistant weeds in garlic fields, such as thistle, resistant bromegrass, and resistant chickweed. Therefore, screening for a highly effective, broad-spectrum herbicide that can completely solve the problem of resistant weeds, reduce their incidence, and is safe for crops has potential application value.

[0005] Therefore, there is a need for a herbicide that can be applied to address the current weed problems in wheat or garlic. Summary of the Invention

[0006] This invention addresses the weed problem currently existing in wheat and garlic fields by providing a mixed herbicide composition containing thiamethoxam and isoproturon, and its application. Using this mixed herbicide composition, a pre- and post-emergence herbicide for wheat and garlic can be prepared to effectively control resistant and difficult-to-control weeds such as resistant alopecuroides, resistant ryegrass, and resistant chickweed in garlic and wheat fields.

[0007] To achieve the above objectives, the technical solution adopted in this application is as follows: A mixed herbicidal composition containing thiamethoxam and isoproturon, wherein the active ingredients of the mixed herbicidal composition include thiamethoxam and isoproturon.

[0008] Preferably, the mass ratio of thiazosulfonamide to isoproturon is 1:2000 to 1:1.

[0009] Preferably, the mass ratio of thiazosulfonamide to isoproturon is 1:400 to 1:10.

[0010] Preferably, the mass percentage of thiamethoxam and isoproturon in the mixed herbicidal composition is 1%-98%.

[0011] Preferably, the mass ratio of thiamethoxam and isoproturon in the mixed herbicidal composition is 20%-80%.

[0012] Preferably, the mixed herbicidal composition contains one or more of a safener, adjuvant, solvent, carrier, emulsifier, or synergist to form an oil suspension, suspension, water emulsion, microemulsion, water-dispersible granules, or wettable powder.

[0013] Preferably, the additive is one or more of the following: emulsifier, synergist, stabilizer, dispersant, wetting agent, penetrant, antifreeze and spreading agent; The solvent is one or more selected from dimethyl sulfoxide, acetone, butanone, cyclohexanone, pyrrolidone, isopropanol, butanol, ethylene glycol, ethyl acetate, butyl acetate, acetonitrile, tetrahydrofuran, machine oil, vegetable oil, and methyl oleate; The carrier is one or more of the following: bentonite, diatomite, kaolin, talc, clay, mica, zeolite, pyrophyllite, precipitated silica, light calcium carbonate, and ammonium sulfate. The emulsifier is a monomer or compound formulation of a nonionic, cationic or anionic surfactant; The synergist is a methylated and / or ethylated vegetable oil, and / or menthol, and the penetrant is one or more of sulfated castor oil, sodium alkyl sulfonate, sodium alkylbenzene sulfonate, azone, thiazone, and organosilicon.

[0014] Preferably, the nonionic surfactant is one or more of alkylphenol polyoxyethylene ether, alkylphenol polyoxypropylene ether, benzylphenol polyoxyethylene ether, phenethyl polyoxyethylene polyoxypropylene ether, fatty acid ethylene oxide ester and dehydrated sorbitan fatty acid ester. The cationic surfactant is one or more of the following: fatty amine salts, fatty primary amine salts, and fatty secondary amine salts; The anionic surfactant is one or more of the following: calcium alkylbenzene sulfonate, calcium alkyl sulfonate, sodium alkyl sulfate, calcium fatty alcohol polyoxyethylene ether sulfate, phenethylphenol polyoxyethylene ether sulfate, and alkyl polyoxyethylene ether phosphate.

[0015] Application of a mixed herbicidal composition containing thiamethoxam and isoproturon in the control of grass and broadleaf weeds in wheat and garlic fields.

[0016] As a preferred application, a mixed herbicidal composition containing thiamethoxam and isoproturon is used for pre-emergence or early post-emergence weed control in wheat and garlic.

[0017] Compared with the prior art, the advantages and positive effects of the present invention are as follows: This invention discloses a mixed herbicidal composition containing thiamethoxam and isoproturon and its application. The thiamethoxam of this application exhibits excellent control efficacy against both grasses and broadleaf weeds, while isoproturon controls annual grasses and some annual broadleaf weeds. Both thiamethoxam and isoproturon possess extremely high pre-emergence and foliar activity, and are safe for subsequent crops. The mixed herbicidal composition utilizes a binary combination of highly effective components with different mechanisms of action to kill weeds, improving the control efficacy against resistant weeds while reducing the development of weed resistance, significantly enhancing the herbicidal activity of the herbicide. It also improves the control of various grasses and broadleaf weeds, exhibiting a complementary weed control spectrum. Therefore, it can be applied to control grasses and broadleaf weeds in wheat and garlic fields, especially in pre-emergence and early post-emergence weed control in wheat and garlic. Detailed Implementation

[0018] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described below with reference to embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0019] Numerous specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways than those described herein, and therefore the invention is not limited to the specific embodiments disclosed in the following specification.

[0020] Example 1, a mixed herbicidal composition of Example 1, comprising, by weight percentage of each component in the composition, 2% thiamethoxam, 25% isoproturon, 6% adjuvant, and 67% carrier; wherein the adjuvant is composed of the following components by weight percentage (percentage of total weight of herbicide): 1.5% dispersant 2700 and 4.5% wetting agent T-1004, and the carrier is composed of the following components by weight percentage (percentage of total weight of herbicide): 15% ammonium sulfate and 52% kaolin.

[0021] The preparation method of Example 1 is as follows: All raw materials are thoroughly mixed, air-jet pulverized, mixed, granulated, dried and sieved according to the above weight percentages to obtain 27% water-dispersible granules.

[0022] Example 2, a mixed herbicidal composition of Example 2, comprising, by weight percentage of each component in the composition, 1% thiamethoxam, 25% isoproturon, 18% adjuvant, 40.5% solvent and 15.5% carrier; wherein, the adjuvant is composed of the following components by weight percentage (percentage of total herbicide weight): 7% dispersant T-80, 3% agricultural emulsion 601# and 11% agricultural emulsion 500#; the solvent is methyl oleate; the carrier is composed of the following components by weight percentage (percentage of total herbicide weight): 6.5% organobentonite and 9% silica; The preparation method of Example 2 is as follows: after fully mixing all raw materials according to the above weight percentages, the mixture is then sand-milled to obtain a 26% oil suspension.

[0023] Example 3, a mixed herbicidal composition of Example 3, comprising, by weight percentage of each component in the composition, 2% thiamethoxam, 75% isoproturon, 5% adjuvants and 18% carrier; wherein, the adjuvants consist of the following components by weight percentage (percentage of total weight of herbicide): 2% wetting agent K-12 and 3% dispersant MF-5, and the carrier consists of the following components by weight percentage (percentage of total weight of herbicide): 12% silica and 6% kaolin. The preparation method of Example 3 is as follows: after thoroughly mixing all raw materials according to the above weight percentages, the mixture is then subjected to air jet milling to obtain a 77% wettable powder.

[0024] Example 4, a mixed herbicidal composition of Example 4, comprising, by weight percentage of each component in the composition, 1% thiamethoxam, 50% isoproturon, 17% adjuvant, 15.5% solvent and 16.5% carrier; wherein, the adjuvant is composed of the following components by weight percentage (percentage of total herbicide weight): 7% dispersant T-80, 3% agricultural emulsion 601# and 7% agricultural emulsion 500#; the solvent is water; the carrier is composed of the following components by weight percentage (percentage of total herbicide weight): 7.5% organobentonite and 9% silica; The preparation method of Example 4 is as follows: after fully mixing all raw materials according to the above weight percentages, the mixture is then sand-milled to obtain a 51% suspension.

[0025] Example 5, a mixed herbicidal composition of Example 5, comprising, by weight percentage of each component in the composition, 1% thiamethoxam, 12.5% ​​isoproturon, 21% adjuvant, 49% solvent and 16.5% carrier.

[0026] The adjuvant consists of the following components by weight percentage (as a percentage of the total weight of the herbicide): 7% dispersant T-80, 3% agricultural emulsion 601# and 11% agricultural emulsion 500#; the solvent is methyl oleate; the carrier consists of the following components by weight percentage (as a percentage of the total weight of the herbicide): 6.5% organobentonite and 9% silica. The preparation method of Example 5 is as follows: after fully mixing all raw materials according to the above weight percentages, the mixture is then sand-milled to obtain an oil suspension of 14.5%. Example 6, a mixed herbicidal composition of Example 6, comprising, by weight percentage of each component in the composition, 1.5% thiamethoxam, 50% isoproturon, 10% adjuvants and 38.5% carrier; wherein the adjuvants consist of the following components by weight percentage (percentage of total weight of herbicide): 4% wetting agent K-12 and 6% dispersant MF-5, and the carrier consists of the following components by weight percentage (percentage of total weight of herbicide): 25% silica and 13.5% kaolin. The preparation method of Example 6 is as follows: after thoroughly mixing all raw materials according to the above weight percentages, the mixture is then subjected to air jet milling to obtain a 51.5% wettable powder.

[0027] Experiment 1: Indoor combined toxicity determination of the combination of thiamethoxam and isoproturon: Target weeds: resistant Alopecurus aequalis and Broccoli.

[0028] Test reagents: thiamethoxam and isoproturon.

[0029] Test method: Indoor pot method. A fixed amount of resistant *Alopecurus aequalis* seeds were sown in seedling pots with a diameter of 9 cm, with approximately 20 weed seeds per pot. The pots were cultured in a plant culture room. When the resistant *Alopecurus aequalis* reached the 3-leaf stage, a fixed amount of *Brassica rapa* seeds were sown in seedling pots with a diameter of 9 cm, with approximately 20 weed seeds per pot. The bottom of each pot was allowed to absorb water and stand for 12 hours. Spraying was then performed using a 3WP-2000 type portable sprayer. Resistant *Alopecurus aequalis* was treated with foliar spraying, while *Brassica rapa* was treated with soil spraying. After treatment, the test materials were placed in a plant culture room for cultivation. The weed control effect of each treatment was observed periodically. After 15 days, the aboveground fresh weight or plant fresh weight was measured, and the toxicity of the herbicide against the target weed was evaluated using the fresh weight inhibition rate (%).

[0030] Calculation method: Fresh weight inhibition rate (%) = [(Control fresh weight - Treatment fresh weight) / Control fresh weight] * 100 Combined effect evaluation method: The Gowing method is used to evaluate the combined action of herbicides, and the formula is as follows: E0 = X + Y(100-X) / 100, where X is the weed control efficacy of herbicide 1, Y is the weed control efficacy of herbicide 2, E0 is the theoretical control efficacy of the mixed herbicide, and E is the actual control efficacy of the mixed herbicide.

[0031] Evaluation criteria: E-E0 > 10% indicates a synergistic effect; E-E0 < -10% indicates an antagonistic effect; E-E0 values ​​between -10% and 10% indicate an additive effect. The experimental results are shown in Tables 1 and 2. Table 1. Indoor toxicity assays of thiamethoxam, isoproturon, and their binary combinations against *Alopecurus aequalis*.

[0032] Table 2. Indoor toxicity assays of thiamethoxam, isoproturon, and their binary combinations on bromelain.

[0033] As shown in Tables 1 and 2, the actual control efficacy of the mixture of thiamethoxam and isoproturon was significantly higher than the expected theoretical control efficacy, showing a clear synergistic or additive-like synergistic effect. Among them, the ratios of thiamethoxam and isoproturon at 1:6.25, 1:25, 1:37.5, 1:50, 1:100, and 1:300 showed a synergistic effect on soil spraying of bromegrass and foliar spraying of resistant Alopecurus aequalis indica.

[0034] Experiment 2: Indoor safety and herbicidal activity verification experiment of a mixed herbicidal composition containing thiamethoxam and isoproturon: Target crops: wheat, garlic.

[0035] Target weeds: Ryegrass multiflora and sedge.

[0036] Test reagents: Examples 1-6.

[0037] Test method: Indoor pot method. Quantities of garlic, wheat, ryegrass, and pigweed seeds were sown separately in 9 cm diameter seedling pots, with an appropriate amount of seeds in each pot. The plants were cultivated in a plant culture room at staggered times: before wheat emergence, at the one-leaf stage, and at the three-leaf stage; and before garlic and weeds emergence, and at the one-leaf stage. Spraying was performed using a 3WP-2000 type portable sprayer. After treatment, the test materials were placed in the plant culture room for cultivation. The inhibition degree of each treatment on wheat and garlic, and the control efficacy against weeds, were observed periodically. The fresh weight of the aboveground parts was measured after 15 days. The inhibition rate (%) or the fresh weight control efficacy was used to evaluate the inhibition degree of the pesticide on the target crops and the control efficacy against weeds.

[0038] Calculation method: Fresh weight inhibition rate / Fresh weight control efficacy (%) = [(Control fresh weight - Treatment fresh weight) / Control fresh weight] * 100.

[0039] The experimental results are shown in Tables 3 and 4: Table 3. Results of indoor safety verification tests of the mixed herbicidal compositions of Examples 1-6

[0040] Table 4. Results of herbicidal activity verification tests on the mixed herbicidal compositions of Examples 1-6

[0041] As shown in Tables 3 and 4, the spraying treatments of Examples 1-6 of this application showed no obvious phytotoxicity symptoms on wheat before emergence, at the one-leaf stage, and at the three-leaf stage, and on garlic before emergence and at the one-leaf stage. The treatments on wheat and garlic in each example were safe. The soil-sealing and foliar treatments of resistant ryegrass and pigweed showed excellent control effects. Although some weeds emerged in the soil treatment of each example, the emerging weeds all showed symptoms of phytotoxicity, such as withered and dead new leaves and severe yellowing of leaves. Visually, the weeds gradually died as they grew. The foliar spraying treatments of Examples 1-6 showed symptoms of complete weed death on resistant ryegrass and pigweed.

[0042] Experiment 3: Field efficacy and safety test of a herbicidal composition containing thiamethoxam and isoproturon: Test reagents: The six binary compound herbicides in Examples 1-6.

[0043] Control drug: 3% thiamethoxam suspension (prepared by conventional method), 50% isoproturon wettable powder (prepared by conventional method).

[0044] Test crops: wheat and garlic.

[0045] Wheat was treated with soil spraying and post-emergence foliar spraying at the three-leaf stage; garlic was treated with pre-emergence sealing treatment after the seedlings emerged.

[0046] Target of prevention and control: Resistance can be seen in weeds such as wheatgrass, purslane, hard grass, pigweed, and chickweed.

[0047] Test method: Accurately weigh all the pesticides according to the area of ​​the test plot, dilute them with water, and then use a backpack sprayer to spray evenly. Use a fan-shaped nozzle specifically designed for herbicides. When spraying, ensure that the pesticide solution is evenly applied to the test plot, avoiding any missed or over-spraying.

[0048] In wheat field trials, weed mortality was observed 15 days after application, and the herbicidal activity of various herbicides was compared. In garlic field trials, weed mortality was observed 25 days after application, and the duration of herbicide efficacy was investigated during the garlic's greening stage. Furthermore, wheat and garlic production was observed 1–25 days after application (based on the effective ingredient dosage per acre) to assess any potential phytotoxicity to the crops.

[0049] The experimental results are shown in Tables 5-7. Table 5. Efficacy results of the binary compound herbicides in Examples 1-6 15 days after soil pretreatment in wheat fields. Treatment agents Dosage (aig / Mu) Broadleaf weed control efficacy (%) Control efficacy against grassy weeds (%) Overall prevention efficacy (%) Example 1 27 94.58 95.89 95.25 Example 2 52 95.93 95.25 95.58 Example 3 77 93.90 93.04 93.45 Example 4 51 92.54 94.30 93.45 Example 5 27 90.17 95.89 93.13 Example 6 51.5 91.86 96.52 94.27 3% Thiamethoxam Suspension 2 86.78 88.61 87.73 50% Isoproturon Wettable Powder 80 63.39 82.91 73.49 Table 6. Efficacy results of the binary compound herbicides in Examples 1-6 15 days after foliar spraying in wheat fields. Treatment agents Dosage (aig / Mu) Broadleaf weed control efficacy (%) Control efficacy against grassy weeds (%) Overall prevention efficacy (%) Example 1 27 97.69 98.05 97.86 Example 2 52 98.61 97.56 98.10 Example 3 77 99.07 96.59 97.86 Example 4 51 97.69 95.61 96.67 Example 5 27 98.15 98.54 98.34 Example 6 51.5 97.22 97.07 97.15 3% Thiamethoxam Suspension 2 77.78 80.49 79.10 50% Isoproturon Wettable Powder 80 57.41 70.24 63.66 Table 7. Efficacy results of the binary compound herbicides in Examples 1-6 in soil sealing tests in garlic fields, 25 days after application. Treatment agents Dosage (aig / Mu) Broadleaf weed control efficacy (%) Control efficacy against grassy weeds (%) Overall prevention efficacy (%) Example 1 27 97.69 98.05 97.86 Example 2 52 98.61 97.56 98.10 Example 3 77 99.07 96.59 97.86 Example 4 51 97.69 95.61 96.67 Example 5 27 98.15 98.54 98.34 Example 6 51.5 97.22 97.07 97.15 3% Thiamethoxam Suspension 2 77.78 80.49 79.10 50% Isoproturon Wettable Powder 80 57.41 70.24 63.66 As shown in Tables 5-7, the binary compound herbicide of this application can significantly improve weed control efficacy compared with single agents, and can achieve a soil sealing effect of over 90% against weeds in wheat fields, with an excellent effect of over 95% in stem and leaf activity; for mulched garlic, the soil sealing activity is over 95%, which can basically achieve the effect of completely sealing weeds, and the effective period can reach about 5 months. Even 155 days after application, it still has excellent effect.

[0050] The safety of wheat and garlic was continuously monitored after the application of the pesticide. Both wheat and garlic were safe, and no obvious symptoms of pesticide damage such as chlorosis, wilting, or dwarfing appeared. All experimental treatments were safe for both garlic and wheat.

[0051] The experimental results show that the combination of the two herbicides in the examples exhibits excellent weed control efficacy, effectively controlling both grasses and broadleaf weeds, with a long-lasting effect. Although the active ingredient content in the dosage used in the examples is lower than the sum of the effective contents of the two individual herbicides, the weed control efficacy is significantly higher than that of either herbicide alone. Furthermore, it is highly safe for wheat and garlic.

[0052] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments that can be applied to other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A mixed herbicidal composition containing thiamethoxam and isoproturon, characterized in that, The active ingredient of the mixed herbicidal composition consists of thiamethoxam and isoproturon; the mass ratio of thiamethoxam to isoproturon is 1:6.25, 1:25, 1:37.5, 1:50, 1:100 or 1:

300.

2. The herbicidal composition containing thiamethoxam and isoproturon according to claim 1, characterized in that, The mass percentage of thiamethoxam and isoproturon in the mixed herbicidal composition is 1%-98%.

3. The herbicidal composition containing thiamethoxam and isoproturon according to claim 2, characterized in that, The mass percentage of thiamethoxam and isoproturon in the mixed herbicidal composition is 20%-80%.

4. The application of a mixed herbicidal composition containing thiamethoxam and isoproturon according to claim 1 in controlling grassy weeds in wheat fields and / or garlic fields, characterized in that, The grassy weeds mentioned are resistant Alopecurus aequalis and Broccoli.

5. An application according to claim 4, characterized in that, The applications are as follows: pre-emergence soil sealing treatment of wheat fields with a mixed herbicidal composition containing thiamethoxam and isoproturon; post-emergence foliar spraying treatment of wheat at the three-leaf stage; and pre-emergence soil sealing treatment of garlic fields.

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