A herbicidal composition, method and use thereof for weed control in a field of rye grass seeds

Abstract

This invention belongs to the field of integrated weed control technology in agriculture, specifically relating to a weed control composition, method, and application for weed control in new wheatgrass seed fields. It includes two treatments: post-sowing soil treatment, where, 1-3 days after sowing, a mixture of pendimethalin EC and a sand-fixing agent is sprayed onto the soil; and seedling foliar treatment, where, at the 3-5 leaf stage of new wheatgrass and the 2-4 leaf stage of weeds, a mixture of 2,4-D dimethylamine salt and the same sand-fixing agent is sprayed onto the weed foliage. The dosage of pendimethalin EC is 150-200 mL / mu, and the dosage of 2,4-D dimethylamine salt is 80-100 mL / mu. This invention combines chemical weed control with physical sand fixation, effectively controlling weeds while reducing phytotoxicity and environmental risks, providing a safe, efficient, and environmentally friendly integrated weed control solution for new wheatgrass seed fields.

Description

Technical Field

[0001] This invention belongs to the field of integrated management of agricultural weeds, specifically relating to a weed control composition, method and application for weed control in wheatgrass seed fields. Background Technology

[0002] New wheatgrass ( Psathyrostachys juncea As an important perennial forage grass, wheatgrass plays a crucial role in grassland construction and ecological restoration in arid and semi-arid regions. Its seed production is a fundamental link in ensuring seed supply and promoting the sustainable development of the grass-based livestock industry. However, in the production practice of new wheatgrass seed fields, weed infestation is one of the main bottlenecks restricting the improvement of seed yield and quality. Field weeds not only fiercely compete with the target crop for resources such as water, fertilizer, and light, leading to inhibited growth and reduced tillering of new wheatgrass, but they can also become intermediate hosts for pests and diseases, directly affecting seed purity, germination rate, and final yield.

[0003] Currently, weed control in wheatgrass seed fields mainly relies on manual weeding and single-method chemical weeding. Manual weeding is inefficient, labor-intensive, and costly, making it difficult to implement, especially in large-scale seed production. While chemical weeding is more efficient, its application in wheatgrass fields faces specific challenges: First, wheatgrass is sensitive to many common herbicides, and improper herbicide selection can easily cause phytotoxicity, affecting germination, seedling growth, and even the reproductive development of mature plants. Second, wheatgrass seed fields are often located in ecologically fragile areas with frequent wind and sand activity. Traditional spraying operations suffer from significant problems such as herbicide drift, volatilization, and soil runoff due to wind and water erosion. This not only reduces the actual efficacy of herbicides, leading to the need for multiple applications, increasing production costs, and easily causing weed resistance, but also results in non-targeted diffusion of herbicides in the environment, leading to potential ecological pollution.

[0004] Therefore, there is an urgent need for a herbicidal composition, method, and application for weed control in new wheatgrass seed fields. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a herbicidal composition, method, and application for weed control in new wheatgrass seed fields, as detailed below: A weed control method for new wheatgrass seed fields includes at least one of the following treatments: Post-sowing soil treatment: 1-3 days after sowing new wheatgrass seeds, mix pendimethalin EC with sand-fixing agent and spray the soil surface of the field. Seedling stage foliage treatment: When the new wheatgrass has emerged at the 3-5 leaf stage and the weeds in the field are at the 2-4 leaf stage, mix the herbicide 2,4-D dimethylamine salt with the sand-fixing agent and spray it on the stems and leaves of the weeds.

[0006] Furthermore, the content of pendimethalin in pendimethalin emulsifiable concentrate is 330 g / L.

[0007] Moreover, the sand-fixing agent is a membrane quantum sand-fixing agent, which is diluted with water at a mass ratio of 1:65-75 before use.

[0008] Furthermore, during post-sowing soil treatment, the application rate of the herbicide pendimethalin emulsifiable concentrate is 150-200 mL / mu, and the application rate of the sand-fixing agent is 0.4-0.8 kg / mu.

[0009] Furthermore, during the foliar application of the herbicide 2,4-D dimethylamine salt, the application rate is 80-100 mL / mu, and the application rate of the sand-fixing agent is 0.4-0.8 kg / mu.

[0010] On the other hand, the present invention provides a weed control composition for new wheatgrass seed fields, the weed control composition comprising a herbicide and a sand-fixing agent; the herbicide is pendimethalin EC and / or 2,4-D dimethylamine salt; the sand-fixing agent is a membrane quantum sand-fixing agent.

[0011] It also provides the application of herbicidal compositions for removing weeds from new wheatgrass seed fields.

[0012] Furthermore, the dosage of the dimethyl pendimethalin emulsifiable concentrate is 150-200 mL / mu, and the dosage of the 2,4-D dimethylamine salt is 80-100 mL / mu; the amount of the sand-fixing agent used is the amount of its diluted solution.

[0013] The membrane quantum sand-fixing agent used in this invention was provided by Shandong Runhan New Material Technology Co., Ltd.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention screened and identified two herbicides, pendimethalin EC (post-sowing soil treatment) and 2,4-D dimethylamine salt (seedling foliar treatment), which, while exhibiting significant weed control efficacy, showed a phytotoxicity level of 0 against wheatgrass, demonstrating extremely high crop safety and solving the problem of phytotoxicity caused by traditional herbicides. Furthermore, this invention uses a mixture of herbicides and a membrane quantum sand-fixing agent. Experimental results show that after adding the sand-fixing agent, the covering film formed by the sand-fixing agent can reduce the evaporation and drift of the herbicide solution, prolong the retention time of the herbicide on the weed surface, and significantly improve the plant control efficacy and fresh weight control efficacy of both pendimethalin EC and 2,4-D dimethylamine salt, thereby improving the utilization rate of the herbicides.

[0015] 2. The new method for weed control in wheatgrass seed fields provided by this invention effectively reduces the loss and drift of herbicides caused by wind and water erosion by the application of sand-fixing agents, thereby reducing the risk of environmental pollution. At the same time, the combination of soil sealing and foliar treatment helps to delay the development of herbicide resistance in weeds.

[0016] 3. The weed control method for new wheatgrass seed fields provided by this invention combines chemical weeding with physical sand fixation techniques. It is suitable for new wheatgrass seed production areas with frequent wind and sand activity and fragile ecology. It can not only control weeds, but also play a role in sand fixation and moisture retention, which helps to improve the field microenvironment and promote the growth of new wheatgrass. Attached Figure Description

[0017] Figure 1 A comparison of the plant control efficacy and fresh weight control efficacy of pendimethalin EC under different dosage treatments; Figure 2 A comparison of plant control efficacy and fresh weight control efficacy under different application rates of pyrifluquinazon; Figure 3 A comparison of the control efficacy and fresh weight efficacy of 2,4-D dimethylamine salt at different concentrations; Figure 4 A comparison of the plant control efficacy and fresh weight control efficacy of acesulfame K under different concentrations of acesulfame K; Figure 5 These are before-and-after photos of spraying pesticides on a field of new wheatgrass seeds. Detailed Implementation

[0018] Example 1 A weed control method for new wheatgrass seed fields is as follows: One day after sowing new wheatgrass seeds, mix pendimethalin EC with a sand-fixing agent and spray the mixture onto the soil surface.

[0019] Preferably, the sand-fixing agent is a membrane quantum sand-fixing agent, which is diluted with water at a mass ratio of 1:70 before use.

[0020] Preferably, the application rate of the herbicide pendimethalin emulsifiable concentrate is 200 mL / mu, and the application rate of the sand-fixing agent is 0.6 kg / mu.

[0021] Example 2 A weed control method for new wheatgrass seed fields is as follows: When the new wheatgrass has emerged to the 5-leaf stage and the weeds in the field are at the 4-leaf stage, the herbicide 2,4-D dimethylamine salt is mixed with the sand-fixing agent and sprayed onto the stems and leaves of the weeds.

[0022] Preferably, the sand-fixing agent is a membrane quantum sand-fixing agent, which is diluted with water at a mass ratio of 1:70 before use.

[0023] Preferably, during the foliar treatment at the seedling stage, the application rate of the herbicide 2,4-D dimethylamine salt is 100 mL / mu, and the application rate of the sand-fixing agent is 0.6 kg / mu.

[0024] Example 3 A weed control method for new wheatgrass seed fields is as follows: Post-sowing soil treatment: Three days after sowing new wheatgrass seeds, mix pendimethalin EC with sand-fixing agent and spray the soil surface of the field. Seedling stage foliage treatment: When the new wheatgrass has emerged to the 4-leaf stage and the weeds in the field are at the 3-leaf stage, mix the herbicide 2,4-D dimethylamine salt with the sand-fixing agent and spray the weed stems and leaves.

[0025] Preferably, the sand-fixing agent is a membrane quantum sand-fixing agent, which is diluted with water at a mass ratio of 1:70 before use.

[0026] Preferably, during post-sowing soil treatment, the application rate of the herbicide pendimethalin emulsifiable concentrate is 200 mL / mu, and the application rate of the sand-fixing agent is 0.6 kg / mu.

[0027] Preferably, during the foliar treatment at the seedling stage, the application rate of the herbicide 2,4-D dimethylamine salt is 100 mL / mu, and the application rate of the sand-fixing agent is 0.6 kg / mu.

[0028] Example 4 A weed control composition for new wheatgrass seed fields, the weed control composition comprising a herbicide and a sand-fixing agent; the herbicide is pendimethalin EC and / or 2,4-D dimethylamine salt; the sand-fixing agent is a membrane quantum sand-fixing agent.

[0029] Experimental Section 1. Materials and Methods Experimental Design: A randomized block design was adopted, with a total of 33 treatments and 3 replicates. The plot area was 15 m² (3 m × 5 m), with a 1 m protective row between plots. Deep tillage was performed using a power harrow before sowing, followed by direct row sowing. A soil pre-sealing agent was sprayed 3 days after sowing. Foliar spraying was applied when the new wheatgrass had 3-5 leaves and weeds had 2-4 leaves. The dosage of chlorpyrifos was 15 kg / mu, and the dosage of other foliar sprays was uniformly 30 kg / mu. The dosage of membrane quantum sand-fixing agent (Shandong Runhan New Material Technology Co., Ltd.) was uniformly set at the recommended ratio of sand-fixing agent to water of 1:70. Specific treatments are shown in Table 1.

[0030] Table 1. Different herbicide treatments in wheatgrass seed fields

[0031] 2. Measurement Indicators and Methods 2.1 Security Survey Observe the growth of wheatgrass seedlings after herbicide application to determine the safety of each herbicide for wheatgrass seedlings. The degree of herbicide damage is classified according to the extent of seedling damage: Grade 0: Normal growth, no different from the blank control plant; Grade 1: Less than 20% of leaf tips are scorched, or spots appear on the leaves; Level 2: 20%-50% of the plant leaves show signs of pesticide damage; Level 3: 50%-70% of the plant leaves develop pesticide-damaged spots or 10% of the plant withers; Level 4: 70%-90% of the plant leaves wither or 20% of the plant dies.

[0032] 2.2 Weed Control Efficacy Survey On days 7, 15, and 30 after application, three quadrats (1m × 1m) were randomly selected from each plot. The weed species and number of plants were recorded. After 30 days, the above-ground parts of the weeds were harvested and brought back to the laboratory for immediate fresh weight measurement. The control efficacy per plant and fresh weight control efficacy were calculated according to the formula.

[0033] Control efficacy = (Number of weeds in control area - Number of weeds in treatment area) / Number of weeds in control area × 100% Fresh weight control efficacy = (fresh weight of weeds in the control area - fresh weight of weeds in the treatment area) / fresh weight of weeds in the control area × 100% 3. Results and Analysis 3.1 Safety Investigation of New Wheat Straw The safety of different herbicides and concentrations of wheatgrass varied significantly (as shown in Table 2). Of the four herbicides tested, 7.5% pyrazosulfuron-methyl showed a phytotoxicity level of 4 at all concentrations (6.4-15.4 g / mu), characterized by 70%-90% leaf wilting, indicating extremely poor safety for new wheatgrass and completely failing to meet control requirements. 50% pyrazosulfuron-methyl showed a phytotoxicity level of 0 at low concentrations (15-35 g / mu), but rose to level 1 at high concentrations (45 g / mu), resulting in leaf tip burn or leaf spots in up to 20% of plants, indicating a slight risk of phytotoxicity. 2,4-D dimethylamine salt showed a phytotoxicity level of 0 at concentrations of 60-120 mL / mu. Pendimethalin EC (330 g / L) showed a phytotoxicity level of 0 at concentrations of 100-250 mL / mu, regardless of whether sand-fixing agents were added, with new wheatgrass growth consistent with the control (CK), indicating the best safety.

[0034] Table 2. Results of phytotoxicity tests on wheatgrass under different pesticide treatments.

[0035] 3.2 Control efficacy of different concentrations of herbicides on weeds in wheatgrass seed fields 3.2.1 The weed control effect of different dosages of pendimethalin emulsifiable concentrate on wheatgrass seed fields from Figure 1It can be seen that the control effect of different dosages of pendimethalin EC on weeds in wheatgrass seed fields exhibits a clear pattern. Its plant control efficacy increases significantly with the extension of application time. After 7 days, the plant control efficacy is generally between 54.25% and 65.08%, gradually increasing to 62.11% to 71.97% after 15 days, and reaching a peak of 69.84% to 77.41% after 30 days. The fresh weight control efficacy and the plant control efficacy show the same trend.

[0036] Regarding the concentration gradient, the control efficacy initially increased and then stabilized with increasing dosage. The control efficacy of treatments at 100 mL / mu, 150 mL / mu, and 200 mL / mu increased sequentially. The 30-day control efficacy of the 200 mL / mu treatment reached 77.30%, a significant increase of 7.46% compared to the 100 mL / mu treatment. However, when the concentration increased to 250 mL / mu, the increase in control efficacy was extremely weak, with a 30-day control efficacy of only 77.41% and a fresh weight control efficacy that decreased to 72.46%, showing no significant difference from the 200 mL / mu treatment. This indicates that excessive application beyond the threshold cannot improve the control efficacy.

[0037] After adding the membrane quantum sand-fixing agent, the plant control efficacy and fresh weight control efficacy of all concentration treatments were significantly improved, and the optimization trend was consistent with that of the single application. Treatment with 100 mL / mu + sand-fixing agent: 77.38% plant control efficacy and 74.41% fresh weight control efficacy after 30 days; treatment with 150 mL / mu + sand-fixing agent: 80.85% plant control efficacy and 81.91% fresh weight control efficacy after 30 days; treatment with 200 mL / mu + sand-fixing agent: 82.30% plant control efficacy and 84.32% fresh weight control efficacy after 30 days; treatment with 250 mL / mu + sand-fixing agent: 82.42% plant control efficacy and 85.28% fresh weight control efficacy after 30 days. Although the efficacy was slightly higher than the 200 mL / mu + sand-fixing agent combination, the improvement was less than 1%.

[0038] For specific spraying effects of the 200mL / mu + sand-fixing agent combination, please refer to [link / reference]. Figure 5 As can be seen from the picture, there is a significant difference before and after spraying. After spraying, there are obviously fewer weeds and the plants are growing better.

[0039] 3.2.2 The control effect of different dosages of pyrifluquinazon on weeds in wheatgrass seed fields from Figure 2 It can be seen that the control effect of pyrifluquinazon gradually increases with the extension of the application time, showing obvious residual effect. The control efficacy at 7 days is between 48.27% and 58.11%, which increases to 54.21% to 65.26% at 15 days, and reaches a peak of 59.62% to 69.61% at 30 days. The overall control efficacy by fresh weight is close to the control efficacy at 30 days.

[0040] Regarding concentration gradients, the control efficacy initially showed a significant increase followed by a gradual plateau as the dosage increased. The control efficacy increased sequentially from 15g / mu to 25g / mu and then to 35g / mu. The 30-day control efficacy of the 35g / mu treatment reached 69.61%, a significant increase of 10.00% compared to the 15g / mu treatment. However, when the concentration increased to 45g / mu, the 30-day control efficacy was only 69.50%, a slight decrease of 0.11% compared to the 35g / mu treatment. The increase in fresh weight control efficacy was also less than 1%, and there was no significant difference compared to the 35g / mu treatment. This indicates that 35g / mu had already reached the control efficacy threshold, and excessive application yielded no practical benefit.

[0041] After adding the membrane quantum sand-fixing agent, the plant control efficacy and fresh weight control efficacy of each concentration treatment were significantly optimized. The treatment with 15g / mu + sand-fixing agent showed a plant control efficacy of 70.87% and a fresh weight control efficacy of 67.87% after 30 days; the treatment with 25g / mu + sand-fixing agent showed a plant control efficacy of 75.15% and a fresh weight control efficacy of 71.75% after 30 days; the treatment with 35g / mu + sand-fixing agent showed a plant control efficacy of 78.10% and a fresh weight control efficacy of 75.74% after 30 days; and the treatment with 45g / mu + sand-fixing agent showed a plant control efficacy of 78.77% and a fresh weight control efficacy of 77.08% after 30 days. Although slightly higher than the 35g / mu + sand-fixing agent combination, the improvement was limited. The overall effect was not as good as pendimethalin emulsifiable concentrate.

[0042] 3.2.3 Effects of different dosages of 2,4-D dimethylamine salt on weed control in wheatgrass seed fields from Figure 3 It can be seen that the control effect of 2,4-D dimethylamine salt increases significantly with the extension of application time, demonstrating good residual efficacy. The control efficacy per plant was between 55.85% and 62.77% after 7 days, increased to 62.25% to 69.12% after 15 days, and reached a peak of 71.35% to 80.06% after 30 days. The control efficacy per fresh weight was generally higher than that per plant.

[0043] Regarding the concentration gradient, the control efficacy showed a pattern of first significantly increasing and then slowly increasing with increasing dosage. The control efficacy of treatments at 60 mL / mu, 80 mL / mu, and 100 mL / mu increased sequentially. The 30-day control efficacy of the 100 mL / mu treatment reached 78.19%, an increase of 6.84% compared to the 60 mL / mu treatment. When the concentration increased to 120 mL / mu, the 30-day control efficacy was 80.06%, an increase of only 1.87% compared to the 100 mL / mu treatment. The increase in fresh weight control efficacy was also less than 2%, and there was no significant difference compared to the 100 mL / mu treatment.

[0044] After adding the membrane quantum sand-fixing agent, the plant control efficacy and fresh weight control efficacy at all concentrations were significantly better than those achieved by using the agent alone. Treatment with 60 mL / mu + sand-fixing agent: 80.41% plant control efficacy and 80.98% fresh weight control efficacy after 30 days; Treatment with 80 mL / mu + sand-fixing agent: 83.83% plant control efficacy and 85.42% fresh weight control efficacy after 30 days. Treatment with 100 mL / mu + sand fixation agent: 88.13% control efficacy per plant and 88.76% control efficacy per fresh weight after 30 days; Treatment with 120 mL / mu + sand fixation agent: 88.77% control efficacy per plant and 89.63% control efficacy per fresh weight after 30 days. Although the control efficacy of the 120 mL / mu + sand fixation agent treatment is slightly higher, the increase is small.

[0045] 3.2.4 The control effect of different dosages of acesulfame potassium on weeds in wheatgrass seed fields

[0046] from Figure 4 It can be seen that the overall efficacy of acesulfame potassium stands out among the four herbicides, and it increases with the extension of application time. The plant control efficacy is between 60.33% and 71.21% at 7 days, increases to 68.40% to 75.62% at 15 days, and reaches a peak of 77.54% to 83.33% at 30 days. The fresh weight control efficacy is higher than the plant control efficacy, showing a very strong weed suppression ability.

[0047] Regarding the concentration gradient, the control efficacy initially showed a significant increase followed by a slight decrease with increasing dosage. The control efficacy increased sequentially at 6.4 g / mu, 9.4 g / mu, and 12.4 g / mu. The 30-day control efficacy of the 12.4 g / mu treatment reached 83.33%, a significant increase of 5.79% compared to the 6.4 g / mu treatment. However, when the concentration increased to 15.4 g / mu, the 30-day control efficacy decreased to 82.39%.

[0048] After adding the membrane quantum sand-fixing agent, the plant control efficacy and fresh weight control efficacy of each dosage treatment were further improved: 6.4 g / mu + sand-fixing agent treatment: 83.59% plant control efficacy and 86.02% fresh weight control efficacy after 30 days; 9.4 g / mu + sand-fixing agent treatment: 88.98% plant control efficacy and 90.48% fresh weight control efficacy after 30 days; 12.4 g / mu + sand-fixing agent treatment: 92.28% plant control efficacy and 94.72% fresh weight control efficacy after 30 days; 15.4 g / mu + sand-fixing agent treatment: 90.77% plant control efficacy and 93.50% fresh weight control efficacy after 30 days. Combined with Table 2, it can be seen that the phytotoxicity is severe, thus proving its unsuitability.

[0049] 4. Conclusion In summary, the efficacy of the four herbicides is not infinitely positively correlated with their concentration. Each herbicide has a clearly defined optimal concentration threshold. Exceeding this threshold results in very limited improvement in efficacy, or even a slight decline, and may increase the risk of phytotoxicity. Therefore, there is no need to blindly increase the dosage of the herbicides. Precisely controlling the concentration is the key to effective control.

[0050] Pendimethalin EC (150-200 mL / mu) and 2,4-D dimethylamine salt (80-100 mL / mu) both exhibit a herbicide damage level of 0 against new wheatgrass within their respective optimal concentration ranges, demonstrating excellent safety. When combined with membrane-based quantum sand-fixing agents, both plant control efficacy and fresh weight control efficacy are significantly improved, forming a "safe + highly effective" control combination that fully meets the needs of new wheatgrass seed fields. Pyrifluquinazon has an optimal concentration range of 25-35 g / mu. While it shows good control efficacy when combined with sand-fixing agents, its efficacy is lower than that of pendimethalin EC and 2,4-D dimethylamine salt, and slight phytotoxicity exists in the high concentration range. Pyrifluquinazon exhibits severe phytotoxicity in all concentration ranges, failing to meet the core requirements for safe control in new wheatgrass seed fields and is therefore excluded.

[0051] Therefore, after sowing new wheatgrass seeds, it is recommended to use a combination of 150-200 mL / mu of pendimethalin EC + 0.6 kg / mu of sand-fixing agent. During the seedling stage, it is recommended to use a combination of 80-100 mL / mu of 2,4-D dimethylamine salt + 0.6 kg / mu of sand-fixing agent. This approach ensures both efficient weed control and safe growth of new wheatgrass, conforming to the principles of environmentally friendly, precise, and safe pest control, and has significant value for widespread application.

Claims

1. A method for weed control in newly planted wheatgrass seed fields, characterized in that, Including at least one of the following processing methods: Post-sowing soil treatment: 1-3 days after sowing new wheatgrass seeds, mix pendimethalin EC with sand-fixing agent and spray the soil surface of the field. Seedling stage foliage treatment: When the new wheatgrass has emerged at the 3-5 leaf stage and the weeds in the field are at the 2-4 leaf stage, mix the herbicide 2,4-D dimethylamine salt with the sand-fixing agent and spray it on the stems and leaves of the weeds.

2. The weed control method for new wheatgrass seed fields as described in claim 1, characterized in that, The sand-fixing agent is a membrane quantum sand-fixing agent, which is diluted with water at a mass ratio of 1:65-75 before use.

3. The weed control method for new wheatgrass seed fields as described in claim 1, characterized in that, When applying soil treatment after sowing, the application rate of the herbicide pendimethalin EC is 150-200 mL / mu, and the application rate of the sand-fixing agent is 0.4-0.8 kg / mu.

4. The weed control method for new wheatgrass seed fields as described in claim 1, characterized in that, When applying the herbicide 2,4-D dimethylamine salt to the seedlings, the application rate is 80-100 mL / mu, and the application rate of the sand-fixing agent is 0.4-0.8 kg / mu.

5. A weed control method for new wheatgrass seed fields as described in claim 1, characterized in that, The content of pendimethalin in pendimethalin emulsifiable concentrate is 330 g / L.

6. A herbicidal composition for new wheatgrass seed fields, characterized in that, The herbicidal composition comprises a herbicide and a sand-fixing agent; the herbicide is pendimethalin emulsifiable concentrate and / or 2,4-D dimethylamine salt; the sand-fixing agent is a membrane quantum sand-fixing agent.

7. The application of the herbicidal composition according to claim 6, characterized in that, Used to remove weeds from fields with new wheatgrass seeds.

8. The application according to claim 7, characterized in that, The dosage of the dimethyl pendimethalin emulsifiable concentrate is 150-200 mL / mu, and the dosage of the 2,4-D dimethylamine salt is 80-100 mL / mu; the amount of the sand-fixing agent is its diluted solution.

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