The Pesticide adjuvant is a general term for various adjuvants used in addition to the active ingredient in the chemical pesticide processing dosage form. The additive itself has no biological activity, but it is an indispensable additive in the formulation or application. The main purpose of the additive is to improve the efficacy, reduce the dosage of the pesticide, save the cost, and reduce the pollution of the pesticide to the environment. The synergistic effect of auxiliaries on pesticides, especially herbicides, is mainly through increasing the retention of pesticides on the surface of plants, prolonging the residence time and improving the penetration of plant epidermis. The mechanism of action varies depending on the type of additive. In use, surfactants such as emulsifiers and spreading agents are mostly used, and the application is wide, and the effect on the performance of the medicament is also large.
First, the use of additives
1. Surfactant application The addition of surfactant greatly reduces the surface tension of the solution, forming a strong protective film on the surface of the droplets of the emulsion, enhancing the wetting of the agent on the surface of the plant or on the surface of the pest. , spreading, and adhesion to improve efficacy. At present, the main application of pesticide surfactants are: fatty alcohol polyoxyethylenes, alkylphenol polyoxyethylene ethers, sulfonates, sulfonates, amides, silicones, and the like. For example, a non-ionic surfactant and 28% UAN are applied together with chlorsulfuron to effectively prevent ramie. The combination of DC-X2-5394 and methylated sunflower oil enhances the efficacy of chlorsulfuron-methyl with dime and Chlorpyrifos in combination with dicamba and benzoquinone. The dimethylamide Silwet L-77 used for controlling apple trees (including various moths such as leaf roller moths and scale insects) has improved control effect, and can reduce the amount of active ingredients by 50%, and the residual amount on fruits is correspondingly reduced. In the field efficacy test, the jingjingmycin solution added with 0.04% APSA-80 was used 750 times. Within 14 days after the drug, the control effect was the same as that of 500 times, but the control effect was significantly higher after 21 days. By.
In recent years, the development of biosurfactants has also progressed rapidly, and this will also be a promising class of pesticide auxiliaries. Such as multi-functional plant synergist, it contains a variety of alkaloids, glycosides, tannins, etc., with acidic organic chlorine, organic phosphorus (except dichlorvos), organic sulfur, heterocyclic, chloroformate and pyrethroid Mix pesticides to improve the use of pesticides. As a wetting agent and suspending agent, tea saponin has broad development prospects in pesticide wettable powder and has good economic benefits. Other natural surfactants such as vegetable oils and seed kernel powders have been studied.
2. Oils and oils and auxiliaries oil additives can accelerate the absorption efficiency of crops on leaf spray pesticides. They can form uniform and stable emulsions with pesticides and water, and help the target crops absorb pesticides when sprayed. . Commercial petroleum lubricating oil additives and emulsifiers have been applied to the control of three kinds of weeds by Puschte. The wax on the surface of the target crop can be dissolved into the petroleum lubricating oil solution, and its solubility depends on the crop type and growth environment. Different and different.
Vegetable oil additives are much better than petroleum oils and nonionic surfactants in enhancing the bioactivity of herbicides and reducing droplet migration. For example, the control of three weeds is better than the petroleum lubricant additive Clean Crop. Vegetable oil additives can promote absorption conduction and enhance Herbicide control against weeds. Experiments have shown that plant fatty acids and fatty acids are stronger than glycerides. Chester L·Foy et al. pointed out that several additives increased the control effect of the herbicide nicosulfuron on foxtail: methylated sunflower oil> petroleum lubricant> nonionic surfactant WK> non-surfactant X -77.
3. Inorganic salts Some inorganic salt additives can be used to greatly improve the activity of herbicides. These inorganic salts include ammonium sulfate (NH4)2S04, diammonium phosphate (NH4)2HPO4, and sodium sulfate NH4Fe (S04). 2 manganese sulfate MgSO4. However, certain salts can cause damage and resistance to certain herbicides when sprayed. It has been shown that calcium, magnesium, sodium and potassium iron salts will have damage to 2,4-D except calcium sulfate CaSO4, sodium sulfate Na2SO4 and calcium phosphate Ca3(PO4)2 sodium phosphate NaPO4, but this damage It can be reduced by lowering the pH of the solution or by converting 2,4-D into a salt that is difficult to dissociate. Urea, amine nitrate, polyphosphoric acid amine, ammonium sulfate, petroleum lubricating oil and nonionic surfactant are used in combination with chlorhexidine and enephazine to control the large foxtail in cereal crops. The petroleum lubricating oil is larger than the surfactant or salt.
4. Mixing of various additives In practical applications, it is not only a single auxiliary agent. In order to improve the efficacy, a variety of additives can be used at the same time, but care must be taken to overcome the interaction between various additives. In order to prevent the photodegradation of pesticides and other reactions, the efficacy is reduced. Such as the combination of various additives (liquid ammonia, fertilizer, oil, solvent and surfactant), can enhance the activity of the grass in the wheat field and black wheat field, the radiation effect of the residue, enhance the penetration of the active ingredient, Promote its entry into plant tissues. Therefore, to better play the efficacy of pesticides, it is necessary to rationally use and configure various additives. In the same dosage form, different types of additives will significantly affect the performance of the agent. If the agent and the surfactant are incompatible, the suspension rate of the suspension may be lowered. Unsuitable wetting agents and dispersing agents may lower the suspension rate of the wettable powder, and the surfactant may also affect the foliar absorption of the agent. This is especially important in stem and leaf treatment pesticides.
Second, some factors affecting the application of additives
Surfactants are composed of both hydrophilic and hydrophobic components. The ability to reduce surface tension depends on the hydrophilic-hydrophobic correlation and the distribution of molecules between different phases (fog and plant or animal surface). The wet spreading properties of the agent on the target and the amount of retention on the target surface directly affect the penetration of the target surface and the biological activity. Therefore, the addition of a surfactant enhances the spread of the agent molecules on the foliage or the worm, thereby promoting the absorption of the agent. This effect is also related to the temperature, concentration and atmospheric pressure of the solution.
1. The effect of the structure, polarity and concentration of the surfactant on absorption. Syuan Tan et al. studied the effects of nonionic surfactants on 2,4-D foliar adsorption and permeation, and found that polyoxyethylene glycol (PEG) series surfactants can greatly improve the spray on some spray formulations. The osmotic effect of the axillary apple leaf epidermis, but the effect on adsorption is not obvious. The test also indicated that the hydrophilic-lipophilic balance (HLB) of PEG-based surfactants was inversely related to the adsorption of surfactants by the leaf epidermis and the penetration of 2,4-D. The addition of surfactant can increase the penetration of 2,4-D on the stratum corneum membrane, and the permeability decreases with the increase of surfactant HLB value. Therefore, the hydrophilic-lipophilic balance (HLB) value of the surfactant is The change in the penetration of 2,4-D is an important factor.
2. Permeation of compound solutes The amount of substance (ingredient) that penetrates into the epidermis during evaporation is independent of the total amount of solution. The absorption of solutes is related to the fractional coefficient and concentration between the epidermis and the residue, and the rate of permeation depends on the affinity of the solute to the surfactant. The rate of penetration of the compound is not only related to the solubility in the epidermis/wax, but also to the evaporation rate of the solvent. After evaporation, the rate of penetration of the compound will be affected by the concentration in the keratinous waxy layer and epidermis. Surfactants may have the effect of clearing the conduction barrier, hindering the dispersion of the compound, transferring the site of absorption, changing the properties of the compound, reducing its resistance, and creating conditions for the plant to inhale the active compound. The improvement of the permeation performance, the change of the transport disorder in the plant induced by the physical and chemical action (combined dissolution or infiltration mechanism) between the active ingredient of the active agent and the surfactant when infiltrating into the leaf, or the special surfactant Make them easier to penetrate particles.
Third, the development trend of additives
The interaction mechanism between the addition of surfactants and the active ingredients of pesticides and with organisms (worms, plant bodies, bacteria, etc.) was studied, which provided a reliable theoretical basis for the development of applied and efficient additives. . At present, the condensed glucose compound alkyl glycoether composed of a linear alkyl-linked hydrophilic terminal group is attracting new interest and its use is expanding.
From "Agrochemical New Century"
First, the use of additives
1. Surfactant application The addition of surfactant greatly reduces the surface tension of the solution, forming a strong protective film on the surface of the droplets of the emulsion, enhancing the wetting of the agent on the surface of the plant or on the surface of the pest. , spreading, and adhesion to improve efficacy. At present, the main application of pesticide surfactants are: fatty alcohol polyoxyethylenes, alkylphenol polyoxyethylene ethers, sulfonates, sulfonates, amides, silicones, and the like. For example, a non-ionic surfactant and 28% UAN are applied together with chlorsulfuron to effectively prevent ramie. The combination of DC-X2-5394 and methylated sunflower oil enhances the efficacy of chlorsulfuron-methyl with dime and Chlorpyrifos in combination with dicamba and benzoquinone. The dimethylamide Silwet L-77 used for controlling apple trees (including various moths such as leaf roller moths and scale insects) has improved control effect, and can reduce the amount of active ingredients by 50%, and the residual amount on fruits is correspondingly reduced. In the field efficacy test, the jingjingmycin solution added with 0.04% APSA-80 was used 750 times. Within 14 days after the drug, the control effect was the same as that of 500 times, but the control effect was significantly higher after 21 days. By.
In recent years, the development of biosurfactants has also progressed rapidly, and this will also be a promising class of pesticide auxiliaries. Such as multi-functional plant synergist, it contains a variety of alkaloids, glycosides, tannins, etc., with acidic organic chlorine, organic phosphorus (except dichlorvos), organic sulfur, heterocyclic, chloroformate and pyrethroid Mix pesticides to improve the use of pesticides. As a wetting agent and suspending agent, tea saponin has broad development prospects in pesticide wettable powder and has good economic benefits. Other natural surfactants such as vegetable oils and seed kernel powders have been studied.
2. Oils and oils and auxiliaries oil additives can accelerate the absorption efficiency of crops on leaf spray pesticides. They can form uniform and stable emulsions with pesticides and water, and help the target crops absorb pesticides when sprayed. . Commercial petroleum lubricating oil additives and emulsifiers have been applied to the control of three kinds of weeds by Puschte. The wax on the surface of the target crop can be dissolved into the petroleum lubricating oil solution, and its solubility depends on the crop type and growth environment. Different and different.
Vegetable oil additives are much better than petroleum oils and nonionic surfactants in enhancing the bioactivity of herbicides and reducing droplet migration. For example, the control of three weeds is better than the petroleum lubricant additive Clean Crop. Vegetable oil additives can promote absorption conduction and enhance Herbicide control against weeds. Experiments have shown that plant fatty acids and fatty acids are stronger than glycerides. Chester L·Foy et al. pointed out that several additives increased the control effect of the herbicide nicosulfuron on foxtail: methylated sunflower oil> petroleum lubricant> nonionic surfactant WK> non-surfactant X -77.
3. Inorganic salts Some inorganic salt additives can be used to greatly improve the activity of herbicides. These inorganic salts include ammonium sulfate (NH4)2S04, diammonium phosphate (NH4)2HPO4, and sodium sulfate NH4Fe (S04). 2 manganese sulfate MgSO4. However, certain salts can cause damage and resistance to certain herbicides when sprayed. It has been shown that calcium, magnesium, sodium and potassium iron salts will have damage to 2,4-D except calcium sulfate CaSO4, sodium sulfate Na2SO4 and calcium phosphate Ca3(PO4)2 sodium phosphate NaPO4, but this damage It can be reduced by lowering the pH of the solution or by converting 2,4-D into a salt that is difficult to dissociate. Urea, amine nitrate, polyphosphoric acid amine, ammonium sulfate, petroleum lubricating oil and nonionic surfactant are used in combination with chlorhexidine and enephazine to control the large foxtail in cereal crops. The petroleum lubricating oil is larger than the surfactant or salt.
4. Mixing of various additives In practical applications, it is not only a single auxiliary agent. In order to improve the efficacy, a variety of additives can be used at the same time, but care must be taken to overcome the interaction between various additives. In order to prevent the photodegradation of pesticides and other reactions, the efficacy is reduced. Such as the combination of various additives (liquid ammonia, fertilizer, oil, solvent and surfactant), can enhance the activity of the grass in the wheat field and black wheat field, the radiation effect of the residue, enhance the penetration of the active ingredient, Promote its entry into plant tissues. Therefore, to better play the efficacy of pesticides, it is necessary to rationally use and configure various additives. In the same dosage form, different types of additives will significantly affect the performance of the agent. If the agent and the surfactant are incompatible, the suspension rate of the suspension may be lowered. Unsuitable wetting agents and dispersing agents may lower the suspension rate of the wettable powder, and the surfactant may also affect the foliar absorption of the agent. This is especially important in stem and leaf treatment pesticides.
Second, some factors affecting the application of additives
Surfactants are composed of both hydrophilic and hydrophobic components. The ability to reduce surface tension depends on the hydrophilic-hydrophobic correlation and the distribution of molecules between different phases (fog and plant or animal surface). The wet spreading properties of the agent on the target and the amount of retention on the target surface directly affect the penetration of the target surface and the biological activity. Therefore, the addition of a surfactant enhances the spread of the agent molecules on the foliage or the worm, thereby promoting the absorption of the agent. This effect is also related to the temperature, concentration and atmospheric pressure of the solution.
1. The effect of the structure, polarity and concentration of the surfactant on absorption. Syuan Tan et al. studied the effects of nonionic surfactants on 2,4-D foliar adsorption and permeation, and found that polyoxyethylene glycol (PEG) series surfactants can greatly improve the spray on some spray formulations. The osmotic effect of the axillary apple leaf epidermis, but the effect on adsorption is not obvious. The test also indicated that the hydrophilic-lipophilic balance (HLB) of PEG-based surfactants was inversely related to the adsorption of surfactants by the leaf epidermis and the penetration of 2,4-D. The addition of surfactant can increase the penetration of 2,4-D on the stratum corneum membrane, and the permeability decreases with the increase of surfactant HLB value. Therefore, the hydrophilic-lipophilic balance (HLB) value of the surfactant is The change in the penetration of 2,4-D is an important factor.
2. Permeation of compound solutes The amount of substance (ingredient) that penetrates into the epidermis during evaporation is independent of the total amount of solution. The absorption of solutes is related to the fractional coefficient and concentration between the epidermis and the residue, and the rate of permeation depends on the affinity of the solute to the surfactant. The rate of penetration of the compound is not only related to the solubility in the epidermis/wax, but also to the evaporation rate of the solvent. After evaporation, the rate of penetration of the compound will be affected by the concentration in the keratinous waxy layer and epidermis. Surfactants may have the effect of clearing the conduction barrier, hindering the dispersion of the compound, transferring the site of absorption, changing the properties of the compound, reducing its resistance, and creating conditions for the plant to inhale the active compound. The improvement of the permeation performance, the change of the transport disorder in the plant induced by the physical and chemical action (combined dissolution or infiltration mechanism) between the active ingredient of the active agent and the surfactant when infiltrating into the leaf, or the special surfactant Make them easier to penetrate particles.
Third, the development trend of additives
The interaction mechanism between the addition of surfactants and the active ingredients of pesticides and with organisms (worms, plant bodies, bacteria, etc.) was studied, which provided a reliable theoretical basis for the development of applied and efficient additives. . At present, the condensed glucose compound alkyl glycoether composed of a linear alkyl-linked hydrophilic terminal group is attracting new interest and its use is expanding.
From "Agrochemical New Century"
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Chlorpyrifos Insecticide is organophosphate insecticide used in agriculture to control the rice, wheat, cotton, vegetables and other pests, can be used mixed with other insecticides, and synergistic effect obviously, Has the stomach toxicity, tag, fumigation, high efficiency, broad spectrum, low residual organophosphorus, no inner absorption effect.
Chlorpyrifos chemical name: dithio phosphate, white crystal, with slight mercaptan odor. The systemic broad-spectrum insecticidal, acaricidal agent, high volatility in the land.
Other Name: chlorine pyrazole sulfur, phosphorus, sulfur chloride ticks phosphorus
MF.: C9H11Cl3NO3PS
MW.: 350.59
Melting point: 42.5~43℃
Solubility: Slightly soluble in water, soluble in most organic solvents
Density: 1.398 g/mL
Appearance: White crystalline
Chlorpyrifos
Chlorpyrifos Pesticide,Chlorpyrifos Products,Chlorpyrifos Insecticide,Dursban Insecticide
Shijiazhuang Dailun Chemical Co., Ltd. , http://www.dailunchem.com