Method for enhancing leaf surface wetting spreading and control effect of herbicide by using mannosylerythritol lipid

Abstract

The invention relates to the technical field of agricultural chemistry, and discloses a method for enhancing leaf surface wetting spreading and prevention effects of a herbicide by using mannosylerythritol lipid. Comprising the steps of S1, material and equipment preparation, S2, MELs synergist formula optimization, S3, herbicide and MELs synergist compounding, S4, standardized pesticide application process step, S5, effect verification and evaluation step and S6, cost optimization and matters needing attention. The MELs synergist adopted in the method has excellent interfacial activity, the 60s contact angle on hydrophobic wheat leaves is smaller than or equal to 36 degrees under the concentration of 2%, the hydrophilic crop leaf surface contact angle is smaller than or equal to 34 degrees, the canvas sedimentation time is as low as 6.75 s and is far better than that of a traditional auxiliary agent Tween 80, through a standardized pesticide application process, the pesticide liquid can be spontaneously and evenly spread on the hydrophilic and hydrophobic leaf surfaces, and the pesticide liquid adhesion rate is remarkably increased. Compared with a traditional method, the leaf surface adhesion rate is increased by 50% or above, and the problem of liquid medicine loss and waste is effectively solved.

Description

Technical Field

[0001] This invention relates to the field of agricultural chemistry, specifically to a method for enhancing the foliar wetting, spreading, and control efficacy of herbicides using mannose-erythritol esters. Background Technology

[0002] In agricultural weed control, the foliar action efficiency of herbicides directly determines the control effect, and insufficient foliar wetting and spreading performance is a core bottleneck restricting the application of traditional herbicides. Crop leaves exhibit significant differences in hydrophilicity and hydrophobicity (e.g., wheat leaves are hydrophobic, while pepper leaves are hydrophilic). Adjuvants commonly used with traditional herbicides (such as Tween 80) have limited interfacial activity, making it difficult for the herbicide solution to form a uniformly spread film on the leaf surface. Experimental data shows that a 2% concentration of Tween 80 aqueous solution still maintains a contact angle as high as 88° on hydrophobic wheat leaves after 60 seconds, while it is only 63° on hydrophilic pepper leaves, and the settling time on the canvas is as long as 101.3 seconds, indicating a slow wetting speed.

[0003] This makes the herbicide solution prone to agglomerating and forming droplets on the leaves, resulting in not only wasted solution but also difficulty in penetrating the cuticle of weeds, leading to poor efficacy and short-lasting effects. For example, when using 30% benzoxazine SC (recommended dosage 20 ml / acre) alone to treat goosegrass, some weeds remain green even after 14 days, failing to completely control the herbicide. Furthermore, traditional chemical adjuvants are mostly synthetic, have poor biocompatibility, and easily leave residues in soil and crops, failing to meet the demands of modern agriculture for environmentally friendly agricultural inputs. Therefore, developing a herbicide synergist technology that balances excellent wetting and spreading properties, enhanced efficacy, and environmental safety is crucial to solving these problems. Summary of the Invention

[0004] (a) Technical problems to be solved To address the shortcomings of existing technologies, this invention provides a method for enhancing the foliar wetting, spreading, and efficacy of herbicides using mannose-erythritol esters. This method offers advantages such as significantly improved foliar wetting and spreading efficiency and a markedly higher pesticide adhesion rate, thus solving the problem of the pesticide film failing to form a uniformly spread film on the leaf surface.

[0005] (II) Technical Solution To achieve the aforementioned goals of significantly improving foliar wetting and spreading efficiency and significantly increasing pesticide adhesion rate, this invention provides the following technical solution: a method for enhancing the foliar wetting and spreading efficiency and control efficacy of herbicides using mannose-erythritol esters, comprising S1 material and equipment preparation, S2 MELs synergist formulation optimization step, S3 herbicide and MELs synergist compounding step, S4 standardized application process step, S5 effect verification and evaluation step, and S6 cost optimization and precautions. The S1 material and equipment preparation includes S101 core material specifications and parameters and S102 key equipment and parameter settings. Among them, the S2 MELs synergist formulation optimization steps include determining the S201 formulation ratio and the S202 synergist preparation process; The steps for combining S3 herbicide with MELs synergist include setting the S301 mixing ratio, the S302 mixing operation procedure, and the S303 quality testing of the mixed solution. The S4 standardized application process includes S401 pre-application preparation, S402 application operation, and S403 post-application management. The S5 efficacy verification and evaluation steps include S501 wetting and spreading effect verification, S502 dispersion stability verification, S503 efficacy evaluation and S504 safety evaluation. Among them, S6 cost optimization and precautions include S601 cost control strategy and S602 precautions.

[0006] Preferably, the specifications and parameters of the S101 core material are as follows: Mannoerythritol esters (MELs): prepared by fermentation of Candida species, with a purity ≥95%, low HLB value (biological fermentation source), and a pale yellow oily appearance, meeting the dispersibility index (2% aqueous solution D50 initial value ≤49.3nm, PDI≤0.52). Herbicide: 30% benzoxazine suspension concentrate (SC), recommended dosage 20 ml / acre (commercial standard concentration), target weed is goosegrass (potted or field population); Emulsifying system materials: methyl oleate (purity ≥98%), nonionic emulsifier (Tween derivative, HLB value matched with MELs); Auxiliary materials: pure water (conductivity ≤10μS / cm), standard canvas sheet (for wetting performance verification), hydrophilic pepper leaves and hydrophobic wheat leaves (for spreading test), and potted goosegrass (seedlings of uniform age, plant height 5-8cm).

[0007] Preferably, the key equipment and parameter settings for S102 are as follows: Ultrasonic equipment: 300W power, 40kHz frequency, used for solution emulsification and dispersion (set ultrasonic time 5min). Contact angle measuring instrument: accuracy ±0.1°, capable of recording droplet contact angle changes within 0-60s; Laser particle size analyzer (DLS): Test temperature 25℃, detection range 1-1000nm, used for particle size and PDI determination; Spraying equipment: backpack electric sprayer, with a fan-shaped mist nozzle, spraying pressure of 0.3MPa, and droplet size controlled at 100-200μm; Constant temperature storage box: temperature control accuracy ±1℃, used for sample stability storage (25℃).

[0008] Preferably, the S201 formulation ratio is determined (based on material emulsification performance data). A composite emulsification system is used to solve the problem of poor emulsification of oily MELs in water. The optimized formula, by mass fraction, is as follows: Mannoerythritol esters (MELs): 70%; Methyl oleate: 20%; Nonionic emulsifier: 10%; S202 synergist preparation process: Weigh 70g of MELs and 20g of methyl oleate into a 500ml beaker and stir with a magnetic stirrer at 25℃ and 500r / min for 10min to form a homogeneous oil phase mixture. Slowly add 10g of nonionic emulsifier to the oil phase mixture and continue stirring for 15 minutes to ensure complete dispersion of the emulsifier; The mixture was transferred to an ultrasonic device, and the ultrasonic power was set to 300W and the frequency to 40kHz. The ultrasonic treatment lasted for 5 minutes (refer to the ultrasonic parameters in the experimental method) to break up local agglomeration and form a homogeneous and stable MELs synergist stock solution (labeled as optimized synergist #3). Quality verification: Take 1 ml of synergist stock solution and add it to 99 ml of pure water. Stir for 30 seconds and observe. It should form a transparent diluted solution without layering or precipitation, which meets the requirements for field dilution.

[0009] Preferably, the S301 compounding ratio is set as follows: (based on efficacy test dosage data) Based on the target efficacy requirements, two compound formulation schemes are set up, and the total dosage of the compound system is calculated per acre of cultivated land: Basic synergistic formulation: 20ml of 30% benzoxazine SC (recommended dosage) + 60ml of optimized No. 3 synergist + 30L of purified water; High-efficiency synergistic solution: 20ml of 30% benzoxazine SC + 90ml of optimized No. 3 synergist (recommended dosage for commercially available benchmark adjuvants) + 30L of pure water; S302 compounding operation procedure: Measure 30L of pure water and pour it into the medicine tank. Turn on the stirring device (300r / min) and keep stirring at a constant speed. Slowly add 30% of the applied amount of benzoxazine SC, stir for 5 minutes to ensure the herbicide is completely dispersed in the water; Slowly add the optimized No. 3 synergist along the wall of the medicine tank, and continue stirring for 10 minutes to form a uniform mixture of synergist and herbicide; Ultrasonic enhanced dispersion: The compound solution was transferred to an ultrasonic device and ultrasonically treated at 25°C for 5 min (refer to the ultrasonic parameters in the experimental method) to further reduce particle agglomeration and improve dispersion uniformity. S303 compound solution quality testing: Dispersibility testing: The D50 and PDI of the compound solution were measured using a laser particle size analyzer. The requirements were D50 ≤ 67 nm and PDI ≤ 0.53 (refer to the MELs dispersion stability data in Table 2) to ensure that the compound solution does not easily aggregate during long-term storage. Pre-testing of wetting performance: The canvas settling method is used to test the compound solution. The canvas should be completely wetted and the settling time should be ≤10s (based on the settling performance optimization of 6.75s for 2% MELs solution). If the standard is not met, 5-10ml / acre of synergist should be added.

[0010] Preferably, the preparation before application of the pesticide in step S401 includes: Crop and weed conditions: For cornfields, apply the herbicide when the corn is in the 3-5 leaf stage and the target goosegrass is 5-8 cm tall; ensure there is no rainfall within 12 hours before application and no heavy rain within 24 hours after application (to avoid washing away the herbicide solution). Environmental parameter control: Apply the pesticide on a sunny morning with a temperature of around 25℃ and a wind force of ≤3 (matching the experimental test temperature to ensure the stability of MELs interface activity). Spraying equipment debugging: Adjust the sprayer pressure to 0.3MPa, and control the nozzle height to 30-40cm away from the crop leaves to ensure uniform spraying without missed spraying or double spraying; S402 Application Procedure: Pour the qualified compound solution into the sprayer's tank and stir again for 3 minutes to ensure it is mixed evenly. The spraying method is to walk at a constant speed, with the walking speed controlled at 0.8-1.0 m / s. The oscillation amplitude of the nozzle is matched with the row spacing of the crop to ensure that the leaves are evenly covered with pesticide. Dosage control: Apply the compound solution evenly at a rate of 30L per acre to ensure that each corn plant and weed leaf surface receives a uniform film of pesticide, avoiding excessive or insufficient pesticide in some areas. Foliar coverage requirements: For hydrophobic wheat leaves (analogous to the characteristics of weed leaves in cornfields), ensure that the contact angle of the pesticide solution is ≤36° after 60s; for hydrophilic crop leaves, the contact angle is ≤34° after 60s (refer to the spreadability test results), so that the pesticide solution can spread spontaneously without obvious droplet aggregation.

[0011] Preferably, the post-application management of S403 is as follows: If light rain occurs within 4 hours after application, apply half the amount of the compound solution to ensure that the control effect is not affected. Storage of remaining compound solution: After sealing, store in a constant temperature environment of 25℃, avoid direct sunlight, and use within 3 days (based on MEL dispersion stability data, particle size change is small within 3 days). Before use, stir again for 5 minutes and sonicate for 3 minutes.

[0012] Preferably, the S501 wetting and spreading effect verification is as follows: Contact angle measurement: Immediately after application, select 3 corn leaves (hydrophilic) and 3 goosegrass leaves (hydrophobic). Use a contact angle meter to record the contact angle changes at 0s, 15s, 30s, and 60s. The contact angle of the hydrophobic leaves should be ≤36° and that of the hydrophilic leaves should be ≤34° at 60s (consistent with experimental results). Spreading area determination: 10 μL of the compound solution was added to the same position on the leaf, and the spreading area of ​​the droplet was measured after 60 seconds. The spreading area should be ≥50% higher than that of the pure herbicide treatment group (based on the comparison data of the spreading performance of MELs and Tween 80). S502 dispersion stability verification: Sample retention and testing: After application, a portion of the compound solution was retained, and D50, D90, and PDI were measured using a laser particle size analyzer at 0, 3, and 7 days. The requirements were that the increase in D50 within 3 days should be ≤36% (refer to Table 2 for the particle size change of MELs from 49.27nm to 66.96nm over 3 days), the change in PDI should be ≤0.02, and there should be no obvious stratification or precipitation within 7 days.

[0013] Preferably, the S503 protection efficacy evaluation: The efficacy survey was conducted 7 days and 14 days after application. Survey method: A five-point sampling method was used, with each point selected from a 1m radius. 2For each quadrat, record the number of surviving *Eleusine indica* plants and their fresh weight, and calculate the control efficacy (control efficacy = (surviving number of control group plants / fresh weight - surviving number of treatment group plants / fresh weight) / surviving number of control group plants / fresh weight × 100%). Prevention efficacy requirements: Basic synergistic treatment (60ml / acre synergist): 7 days after application, the efficacy is ≥25% higher than the pure herbicide group, and the efficacy remains ≥20% after 14 days; High-efficiency enhancement program (90ml / acre of enhancer): ≥50% increase in efficacy 7 days after application, ≥50% maintained efficacy 14 days after application, and ≥90% chlorosis and wilting rate of Eleusine indica (refer to efficacy test results); S504 security assessment: Crop safety: Observe the growth of corn 7 and 14 days after application, and record changes in leaf color and plant height. The corn should show no yellowing, wilting, or growth inhibition symptoms, and the plant height growth rate should be ≤10% different from the control group. Environmental safety: The residual amount of MELs in the soil was tested 7 days after application. Based on its biodegradability, the residual amount was required to be ≤0.1mg / kg, with no risk of environmental pollution.

[0014] Preferably, the S601 cost control strategy is as follows: Optimization of synergist dosage: For fields with common weed infestations, prioritize the basic synergist regimen of 60ml / acre (25% synergistic effect) to balance control efficacy and cost; when weed density is high, use the 90ml / acre regimen; Production process optimization: MELs adopt large-scale bio-fermentation process to reduce raw material costs; methyl oleate in the emulsification system can be replaced with industrial-grade recycled vegetable oil to further reduce cost per acre; S602 Precautions: MELs synergists are low HLB value surfactants and should not be mixed with high HLB value additives to avoid affecting the emulsification effect; The compound solution should be prepared and used immediately, and the maximum storage time should not exceed 7 days. It should be sealed and protected from light during storage to prevent MELs from oxidizing and becoming ineffective. Wear protective equipment when applying the pesticide to avoid direct skin contact with the compound solution; if contact occurs, immediately rinse with plenty of water. When combining herbicides and synergists, the order of "water first, then herbicide, and finally synergist" must be strictly followed to avoid excessively high local concentrations that could reduce efficacy.

[0015] (III) Beneficial Effects Compared with the prior art, the present invention provides a method for enhancing the foliar wetting, spreading, and control efficacy of herbicides using mannose-erythritol esters, which has the following beneficial effects: 1. This method utilizes mannoerythritol esters to enhance the foliar wetting and spreading efficiency and efficacy of herbicides. This method significantly improves foliar wetting and spreading efficiency and increases the adhesion rate of the herbicide solution. The MELs synergist used in this method exhibits excellent interfacial activity. At a 2% concentration, the contact angle on hydrophobic wheat leaves is ≤36° in 60 seconds, and on hydrophilic crop leaves, the contact angle is ≤34°. The canvas settling time is as low as 6.75 seconds, far superior to the traditional adjuvant Tween 80 (contact angle 88° / 63°, settling time 101.3s). Through standardized application techniques, the herbicide solution can spontaneously and evenly spread on both hydrophilic and hydrophobic leaf surfaces without significant droplet aggregation. The leaf adhesion rate is more than 50% higher than traditional methods, effectively solving the problem of herbicide loss and waste.

[0016] 2. This method utilizes mannosyl erythritol esters to enhance the foliar wetting and spreading of herbicides and their efficacy. This method achieves significantly enhanced and stable herbicide efficacy: based on the penetration-promoting effect of MELs and precise compounding schemes, the basic synergistic scheme (60ml / acre) improves efficacy by ≥25% 7 days after application, and the high-efficiency synergistic scheme (90ml / acre) improves efficacy by ≥50% 7 days after application, and maintains efficacy of ≥50% after 14 days. The chlorosis and drying rate of goosegrass is ≥90%, which completely solves the problems of rapid efficacy decay and weed residue of traditional herbicides and significantly reduces the frequency of re-spraying.

[0017] 3. This method utilizes mannoerythritol esters to enhance the foliar wetting, spreading, and efficacy of herbicides. This method achieves excellent dispersion stability and strong efficacy consistency: after the MELs synergist is combined with the herbicide and subjected to ultrasonic-enhanced dispersion treatment, the initial D50 of the compound solution is ≤67nm, PDI ≤0.53, and the D50 increase within 3 days is ≤36%, with no obvious stratification or sedimentation. This ensures that each weed can come into contact with a uniform concentration of the herbicide solution during field spraying, avoiding localized differences in efficacy and improving the overall stability of the weed control effect.

[0018] 4. This method utilizes mannose-erythritol esters to enhance the foliar wetting and spreading of herbicides and their efficacy. This method achieves high environmental and crop safety, meeting the needs of green agriculture: MELs are biosurfactants produced by fermentation of Candida species yeast, which are biodegradable. The soil residue after application is ≤0.1mg / kg 7 days later, with no risk of environmental pollution. At the same time, the compound system does not cause yellowing or wilt symptoms in corn, and the plant height growth rate is ≤10% different from the blank control group, balancing weed control effect and crop safety, which is in line with the concept of sustainable development in modern agriculture.

[0019] 5. This method utilizes mannose-erythritol esters to enhance the foliar wetting and spreading effect of herbicides and their control efficacy. This method is feasible, flexible in application, and cost-controllable, adaptable to different field scenarios: it provides two compounding schemes. For conventional weed fields, a basic scheme of 60 ml / acre can be used to balance efficacy and cost; for high-density weed fields, a high-efficiency scheme of 90 ml / acre can be used. Through large-scale fermentation production of MELs and the optimization strategy of replacing methyl oleate with industrial-grade regenerated vegetable oil, the cost per acre can be further reduced, demonstrating economic feasibility for widespread application. Detailed Implementation

[0020] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0021] This solution provides a technical approach, specifically a method for enhancing the foliar wetting, spreading, and efficacy of herbicides using mannose-erythritol esters. The method is summarized as follows: This method uses mannoerythritol esters (MELs) derived from bio-fermentation as the core functional component. Based on their excellent wetting and spreading properties, dispersion stability, and biocompatibility, through formulation optimization, precise compounding, and standardized application processes, it significantly improves the adhesion efficiency, penetration ability, and weed control effect of herbicides on crop leaves (both hydrophilic and hydrophobic). This method integrates the interfacial activity parameters of MELs (contact angle ≤36° and canvas settling time 6.75s at 2% concentration) with herbicide synergistic test data (25%-50% synergistic effect at a dosage of 60-90ml per acre), solving the problems of poor leaf adhesion and rapid efficacy decay of traditional herbicides, while also taking into account environmental friendliness and application economy. A method for enhancing the foliar wetting, spreading, and control efficacy of herbicides using mannose-erythritol esters includes the following steps: S1. Material and equipment preparation: S101 core material specifications and parameters: Mannoerythritol esters (MELs): prepared by fermentation of Candida species, with a purity ≥95%, low HLB value (biological fermentation source), and a pale yellow oily appearance, meeting the dispersibility index (2% aqueous solution D50 initial value ≤49.3nm, PDI≤0.52). Herbicide: 30% benzoxazine suspension concentrate (SC), recommended dosage 20 ml / acre (commercial standard concentration), target weed is goosegrass (potted or field population); Emulsifying system materials: methyl oleate (purity ≥98%), nonionic emulsifier (Tween derivative, HLB value matched with MELs); Auxiliary materials: pure water (conductivity ≤10μS / cm), standard canvas sheet (for wetting performance verification), hydrophilic pepper leaves and hydrophobic wheat leaves (for spreading test), and potted goosegrass (seedlings of uniform age, plant height 5-8cm). S102 Key Equipment and Parameter Settings: Ultrasonic equipment: 300W power, 40kHz frequency, used for solution emulsification and dispersion (set ultrasonic time 5min). Contact angle measuring instrument: accuracy ±0.1°, capable of recording droplet contact angle changes within 0-60s; Laser particle size analyzer (DLS): Test temperature 25℃, detection range 1-1000nm, used for particle size and PDI determination; Spraying equipment: backpack electric sprayer, with a fan-shaped mist nozzle, spraying pressure of 0.3MPa, and droplet size controlled at 100-200μm; Constant temperature storage box: temperature control accuracy ±1℃, used for sample stability storage (25℃); S2 MELs synergist formulation optimization steps: S201 formulation ratio determined: (based on material emulsification performance data) A composite emulsification system is used to solve the problem of poor emulsification of oily MELs in water. The optimized formula, by mass fraction, is as follows: Mannoerythritol esters (MELs): 70%; (Core active ingredient, ensuring interfacial activity) Methyl oleate: 20%; (cosolvent, improves the solubility and dispersibility of MELs) Nonionic emulsifier: 10%; (matches the low HLB value of MELs, promotes oil-water mixing) S202 synergist preparation process: Weigh 70g of MELs and 20g of methyl oleate into a 500ml beaker and stir with a magnetic stirrer at 25℃ and 500r / min for 10min to form a homogeneous oil phase mixture. Slowly add 10g of nonionic emulsifier to the oil phase mixture and continue stirring for 15 minutes to ensure complete dispersion of the emulsifier; The mixture was transferred to an ultrasonic device, and the ultrasonic power was set to 300W and the frequency to 40kHz. The ultrasonic treatment lasted for 5 minutes (refer to the ultrasonic parameters in the experimental method) to break up local agglomeration and form a homogeneous and stable MELs synergist stock solution (labeled as optimized synergist #3). Quality verification: Take 1 ml of synergist stock solution and add it to 99 ml of pure water. Stir for 30 seconds and observe. It should form a transparent diluted solution without layering or precipitation, which meets the requirements for field dilution. Steps for combining S3 herbicide with MELs synergist: S301 compound ratio setting: (based on efficacy test dosage data) Based on the target efficacy requirements, two compound formulation schemes are set up, and the total dosage of the compound system is calculated per acre of cultivated land: Basic synergistic formulation: 20ml of 30% benzoxazine SC (recommended dosage) + 60ml of optimized No. 3 synergist + 30L of purified water; High-efficiency synergistic solution: 20ml of 30% benzoxazine SC + 90ml of optimized No. 3 synergist (recommended dosage for commercially available benchmark adjuvants) + 30L of pure water; S302 compounding operation procedure: Measure 30L of pure water and pour it into the medicine tank. Turn on the stirring device (300r / min) and keep stirring at a constant speed. Slowly add 30% of the applied amount of benzoxazine SC, stir for 5 minutes to ensure the herbicide is completely dispersed in the water; Slowly add the optimized No. 3 synergist along the wall of the medicine tank, and continue stirring for 10 minutes to form a uniform mixture of synergist and herbicide; Ultrasonic enhanced dispersion: The compound solution was transferred to an ultrasonic device and ultrasonically treated at 25°C for 5 min (refer to the ultrasonic parameters in the experimental method) to further reduce particle agglomeration and improve dispersion uniformity. S303 compound solution quality testing: Dispersibility testing: The D50 and PDI of the compound solution were measured using a laser particle size analyzer. The requirements were D50 ≤ 67 nm and PDI ≤ 0.53 (refer to the MELs dispersion stability data in Table 2) to ensure that the compound solution does not easily aggregate during long-term storage. Pre-testing of wetting performance: The canvas settling method is used to test the compound solution. The requirement is that the canvas is fully wetted and the settling time is ≤10s (based on the settling performance optimization of 6.75s for 2% MELs solution). If the standard is not met, 5-10ml / acre of synergist needs to be added. S4 Standardized Application Process Steps: Preparations before applying S401 pesticide: Crop and weed conditions: For cornfields, apply the herbicide when the corn is in the 3-5 leaf stage and the target goosegrass is 5-8 cm tall; ensure there is no rainfall within 12 hours before application and no heavy rain within 24 hours after application (to avoid washing away the herbicide solution). Environmental parameter control: Apply the pesticide on a sunny morning with a temperature of around 25℃ and a wind force of ≤3 (matching the experimental test temperature to ensure the stability of MELs interface activity). Spraying equipment debugging: Adjust the sprayer pressure to 0.3MPa, and control the nozzle height to 30-40cm away from the crop leaves to ensure uniform spraying without missed spraying or double spraying; S402 Application Procedure: Pour the qualified compound solution into the sprayer's tank and stir again for 3 minutes to ensure it is mixed evenly. The spraying method is to walk at a constant speed, with the walking speed controlled at 0.8-1.0 m / s. The oscillation amplitude of the nozzle is matched with the row spacing of the crop to ensure that the leaves are evenly covered with pesticide. Dosage control: Apply the compound solution evenly at a rate of 30L per acre to ensure that each corn plant and weed leaf surface receives a uniform film of pesticide, avoiding excessive or insufficient pesticide in some areas. Foliar coverage requirements: For hydrophobic wheat leaves (analogous to the characteristics of weed leaves in cornfields), ensure that the contact angle of the pesticide solution is ≤36° after 60s; for hydrophilic crop leaves, ensure that the contact angle is ≤34° after 60s (refer to the spreadability test results), so that the pesticide solution can spread spontaneously without obvious droplet aggregation; Post-application management of S403: If light rain occurs within 4 hours after application, apply half the amount of the compound solution to ensure that the control effect is not affected. Storage of remaining compound solution: After sealing, store in a constant temperature environment of 25℃, avoid direct sunlight, and use within 3 days (based on MEL dispersion stability data, particle size change is small within 3 days). Before use, stir again for 5 minutes and sonicate for 3 minutes. S5 Performance Verification and Evaluation Steps: S501 wetting and spreading effect verification: Contact angle measurement: Immediately after application, select 3 corn leaves (hydrophilic) and 3 goosegrass leaves (hydrophobic). Use a contact angle meter to record the contact angle changes at 0s, 15s, 30s, and 60s. The contact angle of the hydrophobic leaves should be ≤36° and that of the hydrophilic leaves should be ≤34° at 60s (consistent with experimental results). Spreading area determination: 10 μL of the compound solution was added to the same position on the leaf, and the spreading area of ​​the droplet was measured after 60 seconds. The spreading area should be ≥50% higher than that of the pure herbicide treatment group (based on the comparison data of the spreading performance of MELs and Tween 80). S502 dispersion stability verification: Sample retention and testing: After application, a portion of the compound solution was retained, and D50, D90, and PDI were measured using a laser particle size analyzer at 0, 3, and 7 days. The requirements were that the D50 increase should be ≤36% within 3 days (refer to Table 2 for the particle size change of MELs from 49.27nm to 66.96nm over 3 days), the PDI change should be ≤0.02, and there should be no obvious stratification or precipitation within 7 days. S503 efficacy assessment: The efficacy survey was conducted 7 days and 14 days after application. Survey method: A five-point sampling method was used, with each point selected from a 1m radius. 2 For each quadrat, record the number of surviving *Eleusine indica* plants and their fresh weight, and calculate the control efficacy (control efficacy = (surviving number of control group plants / fresh weight - surviving number of treatment group plants / fresh weight) / surviving number of control group plants / fresh weight × 100%). Prevention efficacy requirements: Basic synergistic treatment (60ml / acre synergist): 7 days after application, the efficacy is ≥25% higher than the pure herbicide group, and the efficacy remains ≥20% after 14 days; High-efficiency enhancement program (90ml / acre of enhancer): ≥50% increase in efficacy 7 days after application, ≥50% maintained efficacy 14 days after application, and ≥90% chlorosis and wilting rate of Eleusine indica (refer to efficacy test results); S504 security assessment: Crop safety: Observe the growth of corn 7 and 14 days after application, and record changes in leaf color and plant height. The corn should show no yellowing, wilting, or growth inhibition symptoms, and the plant height growth rate should be ≤10% different from the control group. Environmental safety: The residual amount of MELs in the soil was tested 7 days after application. Based on its biodegradability, the residual amount was required to be ≤0.1mg / kg, with no risk of environmental pollution. S6 Cost Optimization and Considerations: S601 Cost Control Strategy: Optimization of synergist dosage: For fields with common weed infestations, prioritize the basic synergist regimen of 60ml / acre (25% synergistic effect) to balance control efficacy and cost; when weed density is high, use the 90ml / acre regimen; Production process optimization: MELs adopt large-scale bio-fermentation process to reduce raw material costs; methyl oleate in the emulsification system can be replaced with industrial-grade recycled vegetable oil to further reduce cost per acre; S602 Precautions: MELs synergists are low HLB value surfactants and should not be mixed with high HLB value additives to avoid affecting the emulsification effect; The compound solution should be prepared and used immediately, and the maximum storage time should not exceed 7 days. It should be sealed and protected from light during storage to prevent MELs from oxidizing and becoming ineffective. Wear protective equipment when applying the pesticide to avoid direct skin contact with the compound solution; if contact occurs, immediately rinse with plenty of water. When combining herbicides and synergists, the order of "water first, then herbicide, and finally synergist" must be strictly followed to avoid excessively high local concentrations that could reduce efficacy. Furthermore, the advantages and application prospects of the method: This optimized and improved method integrates the interfacial activity parameters of MELs with field synergistic data, achieving "precise formulation, standardized process, and quantifiable effect." Compared with traditional methods, this method has three major advantages: First, it significantly improves wettability and spreadability, reducing the leaf contact angle to below 36° within 60 seconds and increasing the pesticide adhesion rate by more than 50%; second, it provides long-lasting and stable efficacy, maintaining more than 50% efficacy for 14 days, solving the problem of rapid efficacy decay in traditional herbicides; and third, it is environmentally friendly, as MELs are biodegradable products with no risk of residual pollution. From an application perspective, this method is suitable for enhancing the efficacy of herbicides in fields of various crops such as corn, wheat, and chili peppers, especially for significantly improving the control of hydrophobic foliar weeds. In the future, it can be further expanded to include compound formulations with MEL concentration gradients (0.5%, 1%, 2%), and targeted optimization can be carried out in combination with different herbicide types (broadleaf weed herbicides and grass weed herbicides). At the same time, the cost per acre of MELs can be reduced through large-scale production, promoting its widespread application in agricultural production. Furthermore, this method significantly improves leaf wetting and spreading efficiency and increases pesticide adhesion rate. The MELs synergist used in this method has excellent interfacial activity. At a concentration of 2%, the contact angle on hydrophobic wheat leaves is ≤36° in 60s, and the contact angle on hydrophilic crop leaves is ≤34°. The canvas settling time is as low as 6.75s, which is far superior to the traditional adjuvant Tween 80 (contact angle 88° / 63°, settling time 101.3s). Through standardized application process, the pesticide can spontaneously and evenly spread on hydrophilic and hydrophobic leaf surfaces without obvious droplet aggregation. The leaf adhesion rate is more than 50% higher than that of traditional methods, effectively solving the problem of pesticide loss and waste. Furthermore, this method achieves significantly enhanced and stable herbicide efficacy: based on the penetration-promoting effect of MELs and precise compounding schemes, the basic synergistic scheme (60ml / acre) improves efficacy by ≥25% 7 days after application, the high-efficiency synergistic scheme (90ml / acre) improves efficacy by ≥50% 7 days, and maintains efficacy of ≥50% after 14 days, with the chlorosis and drying rate of goosegrass ≥90%, completely solving the problems of rapid efficacy decay and weed residue of traditional herbicides, and significantly reducing the frequency of reapplication; Furthermore, this method achieves excellent dispersion stability and strong efficacy consistency: after the MELs synergist is compounded with the herbicide and subjected to ultrasonic-enhanced dispersion treatment, the initial D50 of the compound solution is ≤67nm, PDI ≤0.53, and the D50 increase within 3 days is ≤36%, with no obvious stratification and precipitation. This ensures that each weed can come into contact with a uniform concentration of the herbicide solution during field spraying, avoiding local differences in control efficacy and improving the overall stability of weed control effect. Furthermore, this method achieves high environmental and crop safety, meeting the needs of green agriculture: MELs are biosurfactants produced by fermentation of Candida species yeast, which are biodegradable, with soil residues ≤0.1mg / kg 7 days after application, posing no risk of environmental pollution; at the same time, the compound system does not cause yellowing or wilt symptoms in corn, and the plant height growth rate is ≤10% different from the blank control group, balancing weed control effectiveness and crop safety, which is in line with the concept of sustainable development in modern agriculture; Furthermore, this method achieves flexible application and controllable cost, adapting to different field scenarios: it provides two compound schemes, a basic scheme of 60ml / acre for conventional weed fields to balance efficacy and cost, and a high-efficiency scheme of 90ml / acre for high-density weed fields; through the optimization strategy of large-scale fermentation production of MELs and industrial-grade regenerated vegetable oil to replace methyl oleate, the cost per acre can be further reduced, making it economically feasible for widespread application.

[0022] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for enhancing the foliar wetting and spreading effect and control efficacy of herbicides using mannose-erythritol esters, comprising: S1 material and equipment preparation, S2 MELs synergist formulation optimization, S3 herbicide and MELs synergist compounding, S4 standardized application process, S5 efficacy verification and evaluation, and S6 cost optimization and precautions, characterized in that: The preparation of materials and equipment in S1 includes the core material specifications and parameters in S101 and the setting of key equipment and parameters in S102. Among them, the S2 MELs synergist formulation optimization steps include determining the S201 formulation ratio and the S202 synergist preparation process; The steps for combining S3 herbicide with MELs synergist include setting the S301 mixing ratio, the S302 mixing operation procedure, and the S303 quality testing of the mixed solution. The S4 standardized application process includes S401 pre-application preparation, S402 application operation, and S403 post-application management. The S5 efficacy verification and evaluation steps include S501 wetting and spreading effect verification, S502 dispersion stability verification, S503 efficacy evaluation and S504 safety evaluation. Among them, S6 cost optimization and precautions include S601 cost control strategy and S602 precautions.

2. The method for enhancing the foliar wetting, spreading, and control efficacy of herbicides using mannose-erythritol esters according to claim 1, characterized in that: The specifications and parameters of the S101 core material are as follows: Mannoerythritol esters (MELs): prepared by fermentation of Candida species, with a purity ≥95%, low HLB value (biological fermentation source), and a pale yellow oily appearance, meeting the dispersibility index (2% aqueous solution D50 initial value ≤49.3nm, PDI≤0.52). Herbicide: 30% benzoxazine suspension concentrate (SC), recommended dosage 20 ml / acre (commercial standard concentration), target weed is goosegrass (potted or field population); Emulsifying system materials: methyl oleate (purity ≥98%), nonionic emulsifier (Tween derivative, HLB value matched with MELs); Auxiliary materials: pure water (conductivity ≤10μS / cm), standard canvas sheet (for wetting performance verification), hydrophilic pepper leaves and hydrophobic wheat leaves (for spreading test), and potted goosegrass (seedlings of uniform age, plant height 5-8cm).

3. The method for enhancing the foliar wetting, spreading, and control efficacy of herbicides using mannose-erythritol esters according to claim 1, characterized in that: The key equipment and parameter settings for S102 are as follows: Ultrasonic equipment: 300W power, 40kHz frequency, used for solution emulsification and dispersion (set ultrasonic time 5min). Contact angle measuring instrument: accuracy ±0.1°, capable of recording droplet contact angle changes within 0-60s; Laser particle size analyzer (DLS): Test temperature 25℃, detection range 1-1000nm, used for particle size and PDI determination; Spraying equipment: backpack electric sprayer, with a fan-shaped mist nozzle, spraying pressure of 0.3MPa, and droplet size controlled at 100-200μm; Constant temperature storage box: temperature control accuracy ±1℃, used for sample stability storage (25℃).

4. The method for enhancing the foliar wetting, spreading, and control efficacy of herbicides using mannose-erythritol esters according to claim 1, characterized in that: The S201 formulation ratio was determined based on material emulsification performance data. A composite emulsification system is used to solve the problem of poor emulsification of oily MELs in water. The optimized formula, by mass fraction, is as follows: Mannoerythritol esters (MELs): 70%; Methyl oleate: 20%; Nonionic emulsifier: 10%; S202 synergist preparation process: Weigh 70g of MELs and 20g of methyl oleate into a 500ml beaker and stir with a magnetic stirrer at 25℃ and 500r / min for 10min to form a homogeneous oil phase mixture. Slowly add 10g of nonionic emulsifier to the oil phase mixture and continue stirring for 15 minutes to ensure complete dispersion of the emulsifier; The mixture was transferred to an ultrasonic device, and the ultrasonic power was set to 300W and the frequency to 40kHz. The ultrasonic treatment lasted for 5 minutes (refer to the ultrasonic parameters in the experimental method) to break up local agglomeration and form a homogeneous and stable MELs synergist stock solution (labeled as optimized synergist #3). Quality verification: Take 1 ml of synergist stock solution and add it to 99 ml of pure water. Stir for 30 seconds and observe. It should form a transparent diluted solution without layering or precipitation, which meets the requirements for field dilution.

5. The method for enhancing the foliar wetting, spreading, and control efficacy of herbicides using mannose-erythritol esters according to claim 1, characterized in that: The S301 compounding ratio is set as follows: (based on efficacy test dosage data) Based on the target efficacy requirements, two compound formulation schemes are set up, and the total dosage of the compound system is calculated per acre of cultivated land: Basic synergistic formulation: 20ml of 30% benzoxazine SC (recommended dosage) + 60ml of optimized No. 3 synergist + 30L of pure water; High-efficiency synergistic solution: 20ml of 30% benzoxazine SC + 90ml of optimized No. 3 synergist (recommended dosage for commercially available benchmark adjuvants) + 30L of pure water; S302 compounding operation procedure: Measure 30L of pure water and pour it into the medicine tank. Turn on the stirring device (300r / min) and keep stirring at a constant speed. Slowly add 30% of the applied amount of benzoxazine SC, stir for 5 minutes to ensure the herbicide is completely dispersed in the water; Slowly add the optimized No. 3 synergist along the wall of the medicine tank, and continue stirring for 10 minutes to form a uniform mixture of synergist and herbicide; Ultrasonic enhanced dispersion: The compound solution was transferred to an ultrasonic device and ultrasonically treated at 25°C for 5 min (refer to the ultrasonic parameters in the experimental method) to further reduce particle agglomeration and improve dispersion uniformity. S303 compound solution quality testing: Dispersibility testing: The D50 and PDI of the compound solution were measured using a laser particle size analyzer. The requirements were D50 ≤ 67 nm and PDI ≤ 0.53 (refer to the MELs dispersion stability data in Table 2) to ensure that the compound solution does not easily aggregate during long-term storage. Pre-testing of wetting performance: The canvas settling method is used to test the compound solution. The canvas should be completely wetted and the settling time should be ≤10s (based on the settling performance optimization of 6.75s for 2% MELs solution). If the standard is not met, 5-10ml / acre of synergist should be added.

6. The method for enhancing the foliar wetting, spreading, and control efficacy of herbicides using mannose-erythritol esters according to claim 1, characterized in that: Preparations before applying pesticide S401: Crop and weed conditions: For cornfields, apply the herbicide when the corn is in the 3-5 leaf stage and the target goosegrass is 5-8 cm tall; ensure there is no rainfall within 12 hours before application and no heavy rain within 24 hours after application (to avoid washing away the herbicide solution). Environmental parameter control: Apply the pesticide on a sunny morning with a temperature of around 25℃ and a wind force of ≤3 (matching the experimental test temperature to ensure the stability of MELs interface activity). Spraying equipment debugging: Adjust the sprayer pressure to 0.3MPa, and control the nozzle height to 30-40cm away from the crop leaves to ensure uniform spraying without missed spraying or double spraying; S402 Application Procedure: Pour the qualified compound solution into the sprayer's tank and stir again for 3 minutes to ensure it is mixed evenly. The spraying method is to walk at a constant speed, with the walking speed controlled at 0.8-1.0 m / s. The oscillation amplitude of the nozzle is matched with the row spacing of the crop to ensure that the leaves are evenly covered with pesticide. Dosage control: Apply the compound solution evenly at a rate of 30L per acre to ensure that each corn plant and weed leaf surface receives a uniform film of pesticide, avoiding excessive or insufficient pesticide in some areas. Foliar coverage requirements: For hydrophobic wheat leaves (analogous to the characteristics of weed leaves in cornfields), ensure that the contact angle of the pesticide solution is ≤36° after 60s; for hydrophilic crop leaves, the contact angle is ≤34° after 60s (refer to the spreadability test results), so that the pesticide solution can spread spontaneously without obvious droplet aggregation.

7. The method for enhancing the foliar wetting, spreading, and control efficacy of herbicides using mannose-erythritol esters according to claim 1, characterized in that: Post-application management of S403: If light rain occurs within 4 hours after application, apply half the amount of the compound solution to ensure that the control effect is not affected. Storage of remaining compound solution: After sealing, store in a constant temperature environment of 25℃, avoid direct sunlight, and use within 3 days (based on MEL dispersion stability data, particle size change is small within 3 days). Before use, stir again for 5 minutes and sonicate for 3 minutes.

8. The method for enhancing the foliar wetting, spreading, and control efficacy of herbicides using mannose-erythritol esters according to claim 1, characterized in that: Verification of the wetting and spreading effect of S501: Contact angle measurement: Immediately after application, select 3 corn leaves (hydrophilic) and 3 goosegrass leaves (hydrophobic). Use a contact angle meter to record the contact angle changes at 0s, 15s, 30s, and 60s. The contact angle of the hydrophobic leaves should be ≤36° and that of the hydrophilic leaves should be ≤34° at 60s (consistent with experimental results). Spreading area determination: 10 μL of the compound solution was added to the same position on the leaf, and the spreading area of ​​the droplet was measured after 60 seconds. The spreading area should be ≥50% higher than that of the pure herbicide treatment group (based on the comparison data of the spreading performance of MELs and Tween 80). S502 dispersion stability verification: Sample retention and testing: After application, a portion of the compound solution was retained, and D50, D90, and PDI were measured using a laser particle size analyzer at 0, 3, and 7 days. The requirements were that the increase in D50 within 3 days should be ≤36% (refer to Table 2 for the particle size change of MELs from 49.27nm to 66.96nm over 3 days), the change in PDI should be ≤0.02, and there should be no obvious stratification or precipitation within 7 days.

9. The method for enhancing the foliar wetting, spreading, and control efficacy of herbicides using mannose-erythritol esters according to claim 1, characterized in that: The S503 protection efficacy evaluation: The efficacy survey was conducted 7 days and 14 days after application. Survey method: A five-point sampling method was used, with each point selected from a 1m radius. 2 For each quadrat, record the number of surviving *Eleusine indica* plants and their fresh weight, and calculate the control efficacy (control efficacy = (surviving number of control group plants / fresh weight - surviving number of treatment group plants / fresh weight) / surviving number of control group plants / fresh weight × 100%). Prevention efficacy requirements: Basic synergistic treatment (60ml / acre synergist): 7 days after application, the efficacy is ≥25% higher than the pure herbicide group, and the efficacy remains ≥20% after 14 days; High-efficiency enhancement program (90ml / acre of enhancer): ≥50% increase in efficacy 7 days after application, ≥50% maintained efficacy 14 days after application, and ≥90% chlorosis and wilting rate of Eleusine indica (refer to efficacy test results); S504 security assessment: Crop safety: Observe the growth of corn 7 and 14 days after application, and record changes in leaf color and plant height. The corn should show no yellowing, wilting, or growth inhibition symptoms, and the plant height growth rate should be ≤10% different from the control group. Environmental safety: The residual amount of MELs in the soil was tested 7 days after application. Based on its biodegradability, the residual amount was required to be ≤0.1mg / kg, with no risk of environmental pollution.

10. The method for enhancing the foliar wetting, spreading, and control efficacy of herbicides using mannose-erythritol esters according to claim 1, characterized in that: The S601 cost control strategy: Optimization of synergist dosage: For fields with common weed infestations, prioritize the basic synergist regimen of 60ml / acre (25% synergistic effect) to balance control efficacy and cost; when weed density is high, use the 90ml / acre regimen; Production process optimization: MELs adopt large-scale bio-fermentation process to reduce raw material costs; methyl oleate in the emulsification system can be replaced with industrial-grade recycled vegetable oil to further reduce cost per acre; S602 Precautions: MELs synergists are low HLB value surfactants and should not be mixed with high HLB value additives to avoid affecting the emulsification effect; The compound solution should be prepared and used immediately, and the maximum storage time should not exceed 7 days. It should be sealed and protected from light during storage to prevent MELs from oxidizing and becoming ineffective. Wear protective equipment when applying the pesticide to avoid direct skin contact with the compound solution; if contact occurs, immediately rinse with plenty of water. When combining herbicides and synergists, the order of "water first, then herbicide, and finally synergist" must be strictly followed to avoid excessively high local concentrations that could reduce efficacy.