Chemical control method for artemisia weeds in leguminous forage field and herbicide composition thereof

Abstract

The invention provides a chemical prevention and control method for artemisia weeds in leguminous forage fields and a herbicide composition thereof, and belongs to the technical field of weed prevention and control, and the chemical prevention and control method comprises the following steps: (1) before sowing, spraying stems and leaves with a killing herbicide to kill germinated weeds; (2) after sowing, spraying a soil closed herbicide on the earth surface to form a pesticide film to inhibit weed germination; the killing type herbicide is a glufosin.glyphosate compound agent or a 2-methylglufosin.glufosinate-ammonium compound agent; the soil closed herbicide is a binary compound composition of flumioxazin and imazethapyr, or a triple compound composition of pendimethalin missible oil, flumioxazin and imazethapyr; according to the invention, the prevention and control effect and safety of the compound combination of different herbicides on the artemisia weeds in the leguminous forage field are defined, a technical basis is provided for scientific prevention and control of the weeds in the leguminous forage field in the northern semi-arid region, and the herbicide has important practical significance for improving the yield and quality of the forage.

Description

Technical Field

[0001] This invention belongs to the field of weed control technology, specifically a chemical control method for Artemisia genus weeds in leguminous forage fields and its herbicide composition. Background Technology

[0002] Artemisia species are major noxious weeds in leguminous forage fields in the semi-arid regions of northern my country. These weeds possess biological characteristics such as extensive root systems, high reproductive capacity, drought tolerance, and wide adaptability, creating fierce competition with leguminous forage for water, nutrients, and light. Without effective control, they severely inhibit forage emergence and seedling growth, leading to a significant decrease in forage yield and quality, posing a serious threat to the forage industry.

[0003] Currently, weed control in leguminous forage fields still relies primarily on chemical control. Commonly used strategies in existing technologies often involve pre-planting stubble eradication with a single non-selective herbicide (such as glyphosate or glufosinate). However, this method has limited effectiveness against various Artemisia species that have already established dominant populations, and long-term use of a single herbicide can easily lead to herbicide resistance in weeds.

[0004] To improve efficacy, it is common practice to try simple combinations of different herbicides. However, legume forage crops are quite sensitive to many herbicides, and improper combinations can easily cause serious crop damage, such as low germination rate, seedling burn, and growth inhibition. This is especially true for legumes with weak resistance, such as alfalfa, where it is particularly difficult to screen out herbicide combinations that are both highly effective and safe.

[0005] Based on this, the present invention proposes a chemical control method for Artemisia genus weeds in leguminous forage fields. Summary of the Invention

[0006] To address the aforementioned technical problems, this invention proposes a chemical control method for Artemisia weeds in leguminous forage fields and its herbicide composition, as detailed below: A chemical control method for Artemisia weeds in leguminous forage fields includes the following steps: (1) 15-20 days before sowing, use a non-selective herbicide for foliar spraying to kill the germinated weeds; (2) Within 2 days after sowing, apply a soil-sealing herbicide to the ground surface to form a film that inhibits weed germination; The non-selective herbicide is a combination of glufosinate and glyphosate or a combination of methyl glufosinate and glufosinate. The soil-sealing herbicide is a binary compound composition of propyzoxystrobin and imidazoline, or a ternary compound composition of pendimethalin EC, propyzoxystrobin, and imidazoline.

[0007] Furthermore, the non-selective herbicide is a glufosinate-glyphosate compound, and the soil-sealing herbicide is a binary compound composition of propyzoxystrobin and imidazoline.

[0008] Furthermore, the non-selective herbicide is a glufosinate-glyphosate compound, and the soil-sealing herbicide is a ternary compound composition of pendimethalin EC, propyzamide, and imidazoline.

[0009] Furthermore, the non-selective herbicide is a compound of 2,4-methyl glufosinate and the soil-sealing herbicide is a ternary compound composition of pendimethalin EC, propyzamide, and imidazoline.

[0010] Furthermore, the application rate of the non-selective herbicide is: Glufosinate-ammonium compound: 250-400 ml / mu; 2,4-methyl glufosinate-ammonium compound: 170-250 ml / mu; In the aforementioned glufosinate-glyphosate compound, the content of glufosinate is 8-12%, and the content of glyphosate is 25-35%. The 2,4-methyl glufosinate compound has the following composition: glufosinate content is 18-22%, and 2,4-methyl glufosinate content is 7.0-7.4%.

[0011] Furthermore, the application rate of the soil-sealing herbicide is as follows: When the soil-sealing herbicide is a binary compound composition of propyzoxystrobin and imidazoline: The application rate of propyzamide is 8-10 ml / mu, and the application rate of imidacloprid is 100-134 ml / mu. When the soil-sealing herbicide is a three-component combination of pendimethalin EC, propyzamide, and imazalil acetamide: The application rate of pendimethalin EC is 128-160 ml / mu; the application rate of propyzamide is reduced to 80% of that of the binary compound composition; the application rate of imidazolium acetonitrile is reduced to 80% of that of the binary compound composition. The concentration of the dimethomorph emulsifiable concentrate is 300-360 g / L; The concentration of propyzamide is 460-500 g / L suspension. The concentration of the imidazole acetonic acid is 4-6% in aqueous solution.

[0012] Furthermore, the legume forage is arrowhead pea and / or alfalfa.

[0013] Furthermore, the Artemisia species mentioned are at least one of Artemisia annua, Artemisia capillaris, or Artemisia frigida.

[0014] On the other hand, the present invention provides a herbicide composition, characterized in that the composition is selected from one of the following combinations: A combination of glufosinate-glyphosate compound, propyzamide, and imidazoline; A combination of glufosinate-glyphosate compound, pendimethalin emulsifiable concentrate, propyzamide and imidazoline; A composition of 2-methyl glufosinate compound, pendimethalin emulsifiable concentrate, propyzamide and imidazoline.

[0015] Furthermore, when applying pesticides, choose sunny and breezy weather and use flat fan-shaped nozzles for directional spraying to avoid pesticide drift; monitor pasture growth promptly after application, and apply foliar fertilizer to fields with pesticide damage level 2 to promote recovery.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention employs a two-stage application strategy of pre-sowing herbicides and post-sowing herbicides, and has screened out the optimal herbicide compositions: a combination of glufosinate-glyphosate compound, propyzamide, and imidacloprid; a combination of glufosinate-glyphosate compound, pendimethalin EC, propyzamide, and imidacloprid; and a combination of 2,4-methyl-glufosinate compound, pendimethalin EC, propyzamide, and imidacloprid. Using the method provided by this invention to control Artemisia weeds in leguminous forage fields, field trials show that the plant control efficacy reaches 87.6% and 86.2% in *Vicia sativa* and alfalfa fields, respectively, effectively solving the problems of difficult control and unstable efficacy of Artemisia weeds.

[0017] 2. The chemical control method and herbicide composition for Artemisia spp. in leguminous forage fields provided by this invention, through optimized compound combination and dosage control, achieves high control efficacy while significantly reducing initial phytotoxicity to leguminous forage. Test data shows that the phytotoxicity level to crops can be controlled within level 1 (slight reversible spots) while maintaining a relative emergence rate of over 72.3%. This ensures both the safe production of forage and the safety of seedling growth, overcoming the difficulty of balancing weed control and seedling protection in traditional technologies.

[0018] 4. While effectively controlling weeds, this invention reduces the additional costs of replanting and reseeding caused by herbicide damage, improves the uniformity of forage emergence and growth vigor, and helps to increase forage yield and quality, resulting in significant comprehensive economic benefits. At the same time, scientific compounding and rational application of herbicides reduce the blind use and overuse of herbicides, which helps to reduce the pressure on the farmland ecological environment.

[0019] 5. This invention clarifies the control efficacy and safety of different herbicide combinations against Artemisia spp. weeds in leguminous forage fields, providing a technical basis for the scientific control of weeds in leguminous forage fields in the semi-arid region of northern China, and has important practical significance for improving forage yield and quality. Attached Figure Description

[0020] Figure 1Emergence of alfalfa after spraying with a non-selective herbicide (S3); Figure 2 The effect of spraying soil-sealed herbicide (M6) on weed control between rows in alfalfa fields; Figure 3 The initial mild phytotoxicity after spraying S3M6 combination on alfalfa field; Figure 4 The recovery and growth of alfalfa fields after spraying with S3M6 combination herbicide; Figure 5 The occurrence of weeds between rows in the later stage of alfalfa field; Figure 6 Seedling emergence after spraying S3M6 mixture in a field of arrowhead pea. Detailed Implementation

[0021] Example 1

[0022] A chemical control method for Artemisia weeds in leguminous forage fields includes the following steps: (1) 15 days before sowing, use a non-selective herbicide for foliar spraying to kill the germinated weeds; (2) Within 2 days after sowing, use soil-sealing herbicides to spray the ground to form a film that inhibits weed germination.

[0023] Furthermore, the non-selective herbicide is a glufosinate-glyphosate compound, and the soil-sealing herbicide is a binary compound composition of propyzoxystrobin and imidazoline.

[0024] Furthermore, the application rate of the non-selective herbicide is: Glufosinate-glyphosate compound agent 320 ml / mu; In the aforementioned glufosinate-glyphosate compound, the content of glufosinate is 8% and the content of glyphosate is 25%.

[0025] Furthermore, the application rate of the soil-sealing herbicide is: The application rate of propyzamide is 8 ml / mu, and the application rate of imidazoline is 100 ml / mu. The concentration of propyzamide is 480 g / L.

[0026] Furthermore, the legume forage grasses mentioned are arrowhead pea and alfalfa.

[0027] Moreover, the Artemisia species mentioned are Artemisia annua, Artemisia capillaris, and Artemisia frutescens.

[0028] Example 2 A chemical control method for Artemisia weeds in leguminous forage fields includes the following steps: (1) 20 days before sowing, use a non-selective herbicide for foliar spraying to kill the germinated weeds; (2) Within 2 days after sowing, apply a soil-sealing herbicide to the ground surface to form a film that inhibits weed germination; Furthermore, the non-selective herbicide is a glufosinate-glyphosate compound, and the soil-sealing herbicide is a ternary compound composition of pendimethalin EC, propyzamide, and imidazoline.

[0029] Furthermore, the application rate of the non-selective herbicide is: 400 ml / mu of glufosinate-ammonium compound; In the aforementioned glufosinate-glyphosate compound, the content of glufosinate is 10% and the content of glyphosate is 30%.

[0030] Furthermore, the application rate of the soil-sealing herbicide is: The application rate of pendimethalin EC was 128 ml / mu; the application rate of propyzamide was reduced to 80% of that in Example 1, and the application rate of imidacloprid was reduced to 80% of that in Example 1. The concentration of the dimethomorph emulsifiable concentrate is 360 g / L; The concentration of propyzamide is 500 g / L; The concentration of the imidazole acetonic acid is 6%.

[0031] Furthermore, the legume forage grasses mentioned are arrowhead pea and alfalfa.

[0032] Moreover, the Artemisia species mentioned are Artemisia annua, Artemisia capillaris, and Artemisia frutescens.

[0033] Example 3 A chemical control method for Artemisia weeds in leguminous forage fields includes the following steps: (1) 18 days before sowing, use a non-selective herbicide for foliar spraying to kill the germinated weeds; (2) Within 2 days after sowing, use soil-sealing herbicides to spray the ground to form a film that inhibits weed germination.

[0034] Furthermore, the non-selective herbicide is a compound of 2-methyl glufosinate and the soil-sealing herbicide is a ternary compound composition of pendimethalin EC, propyzamide and imidazoline.

[0035] Furthermore, the application rate of the non-selective herbicide is: 210 ml / mu of 2-methyl glufosinate-ammonium compound; The 2,4-methyl glufosinate compound has the following composition: glufosinate content is 20% and 2,4-methyl chloride content is 7.2%.

[0036] Furthermore, the application rate of the soil-sealing herbicide is: The application rate of pendimethalin EC is 128 ml / mu; the application rate of propyzamide is 6.4 ml / mu; and the application rate of imidacloprid is 80 ml / mu. The concentration of the dimethomorph emulsifiable concentrate is 330 g / L; The concentration of propyzamide is 480 g / L; The concentration of the imidazole acetonic acid is 5%.

[0037] Furthermore, the legume forage grasses mentioned are arrowhead pea and alfalfa.

[0038] Moreover, the Artemisia species mentioned are Artemisia annua, Artemisia capillaris, and Artemisia frutescens.

[0039] Experimental Section To clarify the control effects of different herbicides on Artemisia weeds in leguminous forage fields, this invention conducts field plot experiments, sets up chemical herbicide compounding experiments and blank control treatments, and screens suitable herbicide application methods to provide a basis for scientific control.

[0040] 1. Materials and Methods Test reagents: see Table 1.

[0041] Table 1 Test reagents

[0042] Experimental Procedure: The experiment employed a randomized block design, combining non-selective herbicides (S) with soil-applied herbicides (M), with naturally occurring grass (CK) serving as the control. Each plot was 15 m² in size. 2 (5m×3m), with a 2m protection row between cells, and 3 block repetitions, the specific processing is shown in Tables 2 and 3 below: Table 2 Non-selective herbicides

[0043] Table 3 Soil-sealed type

[0044] Table 4. Treatment Maps of Experimental Cells within the Block Group

[0045] 2. Measurement Indicators and Methods 2.1 Survey of Major Weeds Weed surveys were conducted on untreated plots using the inverted "W" 9-point sampling method, with quadrats measuring 0.5m × 0.5m. During sampling, the types and number of weeds within each quadrat were recorded for each plot, and the field meanness, density, frequency, and relative abundance of weeds were calculated.

[0046] Field average occurrence = (Number of quadrats showing a particular weed in the surveyed field / Total number of quadrats surveyed) × 100% Field density = Number of a certain weed plants in the plot / Plot area Field frequency = (Number of plots showing the presence of a certain weed / Total number of plots surveyed) × 100% Relative abundance = (relative uniformity + relative frequency + relative density) × 100% 2.2 Weed Control Efficacy Survey The efficacy and phytotoxicity of the herbicide were investigated 20 days after sowing. At 7, 15, and 30 days after application, three quadrats (1m × 1m) were randomly selected from each plot. The weed species and number of plants were recorded, and the number of leguminous forage seedlings per unit area, their height, and the extent of phytotoxicity were investigated. The plant control efficacy and emergence rate were calculated using the following formula: Control efficacy = (Number of plants in control area - Number of plants in treatment area) / Number of plants in control area × 100% Relative germination rate = (Number of germinations in treatment / Number of germinations in control) × 100% Table 5. Grading Standards for Drug Damage

[0047] 3. Results and Analysis 3.1 Survey of Major Weeds From July to August each year, influenced by factors such as climate and planting patterns, the occurrence and damage of weeds in leguminous forage fields are basically established. At this time, the variety of weeds in the fields is more complete than during the spring and summer germination periods, which is beneficial for a comprehensive understanding of the weed community structure and the degree of damage. Therefore, the survey period was determined to be mid-July 2023. Fields of arrowhead peas and alfalfa within the Baicaoyuan Base in Hohhot were selected for the survey. Different varieties were selected as survey plots, and planting methods included row sowing, hill sowing, and mixed sowing. A total of 5 representative survey plots and 45 quadrats were selected to ensure sample diversity and data reliability.

[0048] The survey showed that there were 10 main weed species in the legume pasture fields, among which Artemisia annua (46.59%), Artemisia capillaris (43.94%), and Artemisia frigida (35.07%) were the dominant species, accounting for 125.60% of the total relative abundance and 73.02% of the total relative density.

[0049] Artemisia annua exhibits an absolute advantage across multiple indicators, with the highest relative abundance and field density, far exceeding other weeds. This indicates that it has the largest population size and strongest competitive ability in leguminous forage fields, reaching the highest level of damage (++++). Furthermore, the presence of Artemisia annua in quadrats, field frequency, and field evenness are all 100%, demonstrating its extremely uniform distribution and high frequency in the field, making it the most prevalent weed in leguminous forage fields.

[0050] Artemisia capillaris and Artemisia frigida were the next most common weeds. Their relative abundance, relative density, and field frequency (100.00%, 91.60%) were all relatively high, and their field averages reached 98.89% and 88.98% respectively, indicating that they were evenly distributed in the field, had a high frequency of occurrence, and their damage level was also ++++. They were the second most common weeds after Artemisia annua.

[0051] The relative abundances of Artemisia annua, Artemisia argyi, and Artemisia selengensis were 38.03%, 31.29%, and 27.29%, respectively, and their relative densities were 38.33%, 20.99%, and 16.58%, respectively. Their field frequencies were all above 79.60%, and their damage levels reached ++++ or +++, indicating that they have a certain population size and distribution range in the field and have a moderate impact on leguminous forage fields.

[0052] The relative abundance of bindweed was 29.47%, the relative density was 23.52%, the field frequency was 65.20%, and the damage level was ++++, indicating that it has a certain population size and distribution in the field and has a certain impact on leguminous forage fields.

[0053] The relative abundance (17.38%, 15.69%, 15.24%) and relative density (3.88%, 9.69%, 8.00%) of Tribulus terrestris, Leymus chinensis, and Digitaria sanguinalis were relatively low, and the average abundance in the field was only 63.47%, 61.24%, and 61.00%, respectively. This indicates that their populations are relatively small and their distribution is relatively scattered, so their impact on leguminous forage fields is relatively small, and the degree of damage is ++ or +++.

[0054] Table 6. Survey of Major Weeds in Leguminous Pasture Fields

[0055] 3.2 The efficacy of different treatments in controlling weeds At the Mengcao Herb Garden in Hohhot, a non-selective herbicide was sprayed on May 5, 2024. Arrowroot and alfalfa were sown on May 20, and a soil sealant was applied two days after sowing. The weather was sunny with a light breeze and an average temperature of 18℃ at the time of application. The application was carried out using a manual sprayer with a flat, fan-shaped nozzle. The effects of the herbicide on pasture and weeds were monitored 20 days after sowing.

[0056] In the experiment in the field of arrowhead pea (Table 7), the plant control efficacy of S3M6 (glufosinate·glyphosate + propyzoxystrobin + imidacloprid acetamide) reached 87.6%, which was the highest level among all treatments. This combination had a significant inhibitory effect on Artemisia weeds, with a weed density of only 8.0 plants / m², a decrease of 87.6% compared with the control area (64.7 plants / m²). The herbicide damage level was 2 (20%-50% of the plants showed herbicide damage spots on the leaves), and the relative emergence rate was 73.9%. This indicates that the herbicide had a certain initial impact on the crop, but the degree of herbicide damage was within the recoverable range, and the crop could recover to normal through its own growth regulation in the later stage. Figure 5 Pea seedling emergence after pesticide spraying Figure 6 The image shows the later growth of peas. As can be seen from the image, the peas sprouted well after being sprayed with S3M6, and their later growth was also good, with good weed control effect.

[0057] S3M9 (glufosinate-ammonium·glyphosate + 80% pendimethalin + 80% propyzamide + 80% imidacloprid) has a plant control efficacy of 86.1%, second only to S3M6. It achieves a weed density of 9.0 plants / m², a herbicide damage level of 1 (leaf tip burn or spotting within 20%), and a relative emergence rate of 79.2%, offering superior safety. It ensures efficient weed control while minimizing impact on early crop growth. S4M9 (glufosinate-ammonium·glyphosate + 80% pendimethalin + 80% propyzamide + 80% imidacloprid) achieves a plant control efficacy of 85.1%, a weed density of 9.7 plants / m², a herbicide damage level of 1, and a relative emergence rate of 80.8%, combining good weed control with crop safety. In addition, S3M8 (glufosinate-ammonium·glyphosate + 80% metolachlor + 80% propyzamide + 80% imidacloprid) showed a plant control efficacy of 84.5% and a phytotoxicity level of 1; S4M6 (2-methyl glufosinate-ammonium + propyzamide + imidacloprid) showed a plant control efficacy of 83.5% and a phytotoxicity level of 2, both demonstrating excellent weed control performance.

[0058] Table 7. Control efficacy against major weeds in arrowhead pea fields.

[0059] In the alfalfa field trial (Table 8), S3M6 (glufosinate·glyphosate + propyzamide + imidacloprid) showed a plant control efficacy of 86.2%, a weed density of 10.0 plants / m², a decrease of 86.2% compared to the control area (72.7 plants / m²), a phytotoxicity level of 2, and a relative emergence rate of 65.3%, demonstrating significant weed control, although it had some impact on the initial emergence of alfalfa. Figure 3 As shown in the image, the alfalfa leaves have slight herbicide damage, but the damage is reversible and can be recovered later. Figure 4 As shown in the figure, the weed control effect was good in the later stage of alfalfa spraying with S3M6, and the recovery of alfalfa phytotoxicity was good. Figure 1 The seedling emergence status of alfalfa fields after spraying with S3. Figure 2 The image shows the effect of spraying M6 on an alfalfa field. It is clear from the image that there are fewer weeds between the rows.

[0060] Both S3M9 (glufosinate-ammonium·glyphosate + 80% pendimethalin + 80% propyzamide + 80% imidacloprid) and S4M9 (2M·glufosinate-ammonium + 80% pendimethalin + 80% propyzamide + 80% imidacloprid) achieved a plant control efficacy of 84.9%, a weed density of 11.0 plants / m², a phytotoxicity level of 1, and a relative emergence rate of 72.3%. They demonstrated high-efficiency weed control while significantly reducing the risk of phytotoxicity to alfalfa, exhibiting outstanding safety. Furthermore, S3M8 (glufosinate-ammonium·glyphosate + 80% metolachlor + 80% propyzamide + 80% imidacloprid) achieved a plant control efficacy of 83.5% and a phytotoxicity level of 1. S4M8 (2-methyl glufosinate + 80% metolachlor + 80% propyzamide + 80% imidacloprid) has a control efficacy of 82.1% and a phytotoxicity level of 1, making it an excellent choice for controlling Artemisia weeds in alfalfa fields.

[0061] Table 8. Control efficacy of major weeds in alfalfa fields

[0062] 4. Conclusion 4.1 Characteristics of the damage caused by Artemisia species in leguminous forage fields This study shows that *Artemisia annua*, *Artemisia capillaris*, and *Artemisia frigida* are the dominant weeds in leguminous forage fields in the Hohhot area, with a combined relative abundance of 125.60%. Furthermore, their field evenness and frequency both exceed 90%, indicating uniform distribution, high population density, and strong competitive stress on forage. *Artemisia annua* has a relative density of 40.26%, with a damage level of ++++, making it the primary target for control; *Artemisia capillaris* and *Artemisia frigida* are the next most prevalent. These three weeds together constitute the core group of the weed community in leguminous forage fields. This result is consistent with the characteristics of weed communities in grassland-type farmland in the semi-arid regions of northern China. Artemisia species, with their drought resistance and high reproduction coefficient, rapidly seize ecological niches during the seedling stage of leguminous forage, inhibiting seedling emergence and growth, ultimately leading to reduced forage yield and quality.

[0063] 4.2 Synergistic control effect of herbicide combinations The experimental results showed that there were significant differences in the control efficacy of different herbicide combinations. Among them, the plant control efficacy of the S3M6 treatment (glufosinate·glyphosate + propyzoxystrobin + imidacloprid) was significantly higher than that of other combinations (e.g., the highest plant control efficacy of the S1 series treatment was only 82.0%, far lower than the 87.6% of S3M6). The combination of glufosinate·glyphosate (S3) and propyzoxystrobin + imidacloprid (M6) showed the strongest synergistic effect, with plant control efficacy of 87.6% and 86.2% against Artemisia selengensis weeds in pea and alfalfa fields, respectively. Glufosinate·glyphosate has both contact and systemic properties, which can quickly kill germinating weeds; propyzoxystrobin achieves pre-emergence weed control by inhibiting chlorophyll synthesis in weeds, while imidacloprid targets the amino acid metabolic pathways of broadleaf weeds. The three have complementary mechanisms of action, effectively covering the critical control periods before and after weed germination.

[0064] 4.3 Differences in the safety of herbicides on leguminous forage grasses Significant differences in the sensitivity of different leguminous forage grasses to herbicides were observed: the relative emergence rate of *Vicia sativa* in all treatments was generally higher than that in alfalfa (e.g., in the S3M6 treatment, the relative emergence rate of *Vicia sativa* was 73.9%, while that of alfalfa was only 65.3%), indicating that alfalfa had weaker tolerance to the tested herbicides. In terms of herbicide damage levels, the compound combinations containing imidazoline (e.g., M6, M9) mostly had a damage level of 2, but all were within the recoverable range, and the forage grasses could recover to normal growth through their own growth regulation later. This result suggests that when applying herbicides in alfalfa fields, treatments with a damage level of 1 (e.g., S3M9, S4M9) should be prioritized to ensure the safety of seedling growth.

[0065] 5. Conclusion 1. Dominant weeds are clearly identified: In the legume forage fields of Hohhot, Artemisia annua, Artemisia capillaris, and Artemisia frigida are the dominant species of Artemisia annua, which are widely distributed and densely distributed, and are one of the main limiting factors for forage production.

[0066] 2. Screening of the optimal prevention and control combination: For leguminous crop fields with strong herbicide resistance, S3M6 (glufosinate-ammonium·glyphosate + propyzamide + imidacloprid) is recommended as the first choice, with a plant control efficacy of 87.6%. Although there is initial phytotoxicity (level 2), it can be recovered. The options that take into account both safety and efficacy are S3M9 (glufosinate-ammonium·glyphosate + 80% pendimethalin + 80% propyzamide + 80% imidacloprid) and S4M9 (2M·glufosinate-ammonium + 80% pendimethalin + 80% propyzamide + 80% imidacloprid), with plant control efficiencies of 86.1% and 85.1%, respectively, phytotoxicity level 1, and relative emergence rate of over 79.2%.

[0067] For leguminous crop fields with weak herbicide resistance, S3M9 and S4M9 treatments are recommended, with a plant control efficacy of 84.9%, a phytotoxicity level of 1, and a relative emergence rate of 72.3%. They effectively control weeds while significantly reducing damage to crop seedlings. If the ultimate control efficacy is desired, S3M6 treatment can be selected, but water and fertilizer management during the seedling stage needs to be strengthened to alleviate phytotoxicity.

Claims

1. A method for the chemical control of Artemisia weeds in leguminous pasture fields, characterized by, It comprises the following steps: (1) Before sowing, foliar spray with a burn-down herbicide to kill the emerged weeds; (2) After sowing, surface spray with a soil-blocking herbicide to form a herbicide film to prevent the weeds from emerging; The burn-down herbicide is a glufosinate-ammonium + glyphosate compound or a 2-methyl + glufosinate-ammonium compound; The soil-blocking herbicide is a binary compound of flupyradifurone and imazethapyr, or a ternary compound of pendimethalin emulsion, flupyradifurone, and imazethapyr.

2. The method of claim 1, wherein, The burn-down herbicide is a glufosinate-ammonium + glyphosate compound, and the soil-blocking herbicide is a binary compound of flupyradifurone and imazethapyr.

3. The method of claim 1, wherein, The burn-down herbicide is a glufosinate-ammonium + glyphosate compound, and the soil-blocking herbicide is a ternary compound of pendimethalin emulsion, flupyradifurone, and imazethapyr.

4. The method of claim 1, wherein, The burn-down herbicide is a 2-methyl + glufosinate-ammonium compound, and the soil-blocking herbicide is a ternary compound of pendimethalin emulsion, flupyradifurone, and imazethapyr.

5. The method of claim 1, wherein, The application amount of the burn-down herbicide is: 250-400 ml / acre for the glufosinate-ammonium + glyphosate compound, and 170-250 ml / acre for the 2-methyl + glufosinate-ammonium compound; The content of glufosinate-ammonium in the glufosinate-ammonium + glyphosate compound is 8-12%, and the content of glyphosate is 25-35%; The content of glufosinate-ammonium in the 2-methyl + glufosinate-ammonium compound is 18-22%, and the content of 2-methyl-4-chloro is 7.0-7.4%.

6. The method of claim 1, wherein, The application amount of the soil-blocking herbicide is: When the soil-blocking herbicide is a binary compound of flupyradifurone and imazethapyr: The application amount of flupyradifurone is 8-10 ml / acre, and the application amount of imazethapyr is 100-134 ml / acre; When the soil-blocking herbicide is a ternary compound of pendimethalin emulsion, flupyradifurone, and imazethapyr: The application amount of pendimethalin emulsion is 128-160 ml / acre, the application amount of flupyradifurone is reduced to 80% of that in the binary compound, and the application amount of imazethapyr is reduced to 80% of that in the binary compound; The concentration of pendimethalin emulsion is 300-360 g / L; The concentration of flupyradifurone is 460-500 g / L; The concentration of imazethapyr is 4-6%.

7. The method according to any one of claims 1 to 6, characterized in that, The leguminous forage grasses are arrowhead pea and / or alfalfa.

8. The method according to any one of claims 1 to 6, characterized in that, The artemisia weeds are at least one of Artemisia annua, Artemisia capillaris, or Artemisia vulgaris.

9. The method according to any one of claims 1 to 6, characterized in that, The time for foliar spray is 15-20 days before sowing, and the time for surface spray is within 2 days after sowing.

10. A herbicidal composition for use in the method of any one of claims 1 to 6, characterized in that, The composition is selected from one of the following combinations: The combination of glufosinate-ammonium + glyphosate compound, flupyradifurone, and imazethapyr; The combination of glufosinate-ammonium + glyphosate compound, pendimethalin emulsion, flupyradifurone, and imazethapyr; The combination of 2-methyl + glufosinate-ammonium compound, pendimethalin emulsion, flupyradifurone, and imazethapyr.

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