(1) There are many varieties and characteristics of symptomatic pesticides, and there are many types of diseases, insects, grasses and rats that control crops. The differences between the localities are also very large, and the habits are also changed. The most suitable pesticides should be selected for the control targets. . Natural organisms (diseases, insects, grasses, rats) have different degrees of resistance in different living environments. For example, the use of deltamethrin to control wheat long-tube aphids is effective in Hebei Province, but not effective in Gansu. If killing pine is used, it is effective in both places; and some agents for controlling bacterial blight in the north, in the north. The show area is an effective medicine, but it is not effective in Guangdong rice area. Therefore, before using pesticides, it is necessary to know the target of prevention and control and to select appropriate pesticide varieties. Refer to books and manuals prepared by the plant protection departments of various places to prevent misuse of pesticides and achieve the ideal effect of symptomatic application.
(2) Timely application of the drug The application period should be based on the development period of the pest and the progress of the crop and the variety of the pesticide. All local pest monitoring stations and rodent monitoring stations should conduct annual monitoring, issue forecasts, and develop prevention and control indicators for major diseases, insects and rodents. If the amount of the disease reaches the prevention and treatment index, it should be controlled by the drug. When applying the medicine, you should also consider the situation of natural enemies in the field, and try to avoid the sensitive period of natural enemies to pesticides. For example, in the case of rodent control, the bait should be applied before the breeding peak of the main dominant species of the local species; when the herbicide is applied, it is necessary to look at the grass and look at the "miao" situation, such as using pre-emergence herbicides, and must not be after emergence. use.
(3) Appropriate application of pesticides When using all kinds of pesticides, they should be used according to the recommended dosage of the product introduction manual. Strictly control the dosage, and can not increase or decrease arbitrarily. Otherwise, it will cause crop phytotoxicity or affect the control effect. During the operation, not only the amount of medicine, the amount of water, and the amount of bait, but also the amount of application area, can be accurately applied in an accurate and appropriate amount to achieve good control effects. There are four ways to indicate the amount of application:
1. For the application of the number of preparations, such as the use of 10% Uranus EC 2-2.5 grams per acre to control cotton bollworm, master the amount of medicine used.
2. Use the amount of active ingredients to represent, such as 25% nitrile emulsifiable concentrate, use 2-4 grams of active ingredient per acre to control wheat powdery mildew.
3. Use the ratio of water to the water, such as 5% bactericidal water clearing agent 100-200 times solution to smear apple tree rot disease spots to prevent rot disease.
4. Use a concentration of parts per million of active ingredient. For example, 2.5% Kungfu emulsifiable concentrate is used to control apple tree peaches. For example, 100 parts per million (abbreviated as 100 ppm), that is, 100 parts of kungfu emulsifiable concentrate in 1 million parts of the diluent. 5-6.3 ppm means that there are 5-6.3 Kung Fu emulsifiable concentrates in 1 million dilutions.
(4) Uniform application The application methods of various dosage forms of pesticides are different, and the instruments used are also different. At present, the main types of applicators are spray equipment, dusting machines, granule spreaders, smoke spray machines, seed dressing machines, etc. There are many types of machines in each category. The tools used for various pesticides have their specific uses and properties. When applying, liquid medicine spraying, powder spraying, granule spraying, and poisoning bait input must consider the performance and characteristics of the instruments and implements used. It can play its due role well, so that the agent can be evenly and evenly distributed on the surface of crops or harmful organisms, and scientific and efficient control results can be obtained.
1. Liquid spray The liquid preparation is the largest and most varied dosage form of pesticide preparation. The quality of the spray in the field depends mainly on the performance of the spray equipment used and the skill level of the operators. The liquid preparation is atomized by means of a spray machine to disperse the liquid into small droplets, so that the surface of the crop or the harmful organism can be uniformly covered to achieve an ideal control effect. However, due to the uniformity of the control objects and the hazard crops, the ideal control effect is achieved. However, due to the different types of crops and the types of crops that are harmful, it is necessary to select suitable machines with different properties. The currently widely used workers and peasants 16 type manual sprayers, pedal sprayers, stretcher type motorized sprayers, etc., are all constant sprays. The latter two sprayers, due to high pressure, high range and long range, are suitable for orchards and forest gardens and can be sprayed on the top and inside of the crown. In the crop field, the worker-peasant 16 manual sprayer is used to carry out the top-loading spray. The lower leaves of the wheat field have more medicines, and the upper leaves have less medicine. The effect of controlling the wheat sucking insects and the tubeworms is good, but it is good for controlling wheat scab and wheat ears. Long tube is not very effective. In the cotton field, the upper leaves of the cotton plant received more medicine, while the lower leaves received less medicine, which was effective for the prevention and control of blind mites, and the control of Fuxi was very poor. Therefore, it is necessary to properly select a suitable application machine for uniform application. The pedal type sprayer and the stretcher type motorized sprayer can spray large trees with high pressure. The disadvantage is that the droplets are large, and the liquid medicine is easily lost from the leaf surface. The loss is generally 60%-70%, and the medicament is wasted. Low-volume spray with Dongfanghong 18 mister can save energy compared with high-volume spray, and has high work efficiency. The general liquid area per unit area, the constant (high capacity) is more than 40 liters, and the ultra-low capacity is less than 0.33 liters. Because the Dongfanghong 18 misting machine can generate powerful airflow by itself, it can be used for ultra-low volume spraying under any circumstances; However, using the Eva-type hand-held ultra-low-capacity sprayer spray, the ultra-low-volume spray method has very small droplets, and it is necessary to send the mist to a certain distance under windy conditions, and it can hardly function when there is no wind, so it is used. For the hand-held sprayer spray, it is required to be used when there is natural wind.
When spraying the herbicide, use a special nozzle, the lasing nozzle, to reduce the damage caused by the fine mist. Ultra-low volume spray method requires atomization fineness to reach about 50 microns, and the droplets can drift in the air for a long time and will not fall to the ground very quickly. When using a hand-held low-low-capacity sprayer, you should not use the turntable nozzle to the lower layer of the crop to use it. Otherwise, it will not be able to perform its proper function, but will cause damage to the crop.
2. Powder spray powder is divided into low concentration powder, high concentration powder, anti-flushing powder, ultrafine powder. When using powder, manual or motorized dusting equipment is used. The airflow generated by the duster can blow the powder to spread evenly and form a good deposit on the surface of the plant and on the surface of the insect. This is mainly due to adhesion or electrostatic adsorption. The adhesion is small, but on the surface of the organism with water film, the adhesion ability of the powder can be improved, so the operation of the dusting operation often requires that the early and late crop leaves are wet or dewed. When the wind is strong, the wind speed exceeds 1 meter per second. Do not spray the powder to avoid waste of the powder. The average dosage of the acre is 1500-2000 grams.
Low-concentration powder: It can be sprayed directly in the field.
High-concentration powder: Also known as high-concentration mother powder, it is mixed with a certain fineness of filler during use, and then sprayed.
Anti-flushing powder: It is a kind of powder with larger particle size, or adding coagulant in the powder to polymerize small particles into larger particles to overcome the drift phenomenon when the powder is used.
Ultrafine powder: mainly used in greenhouses, the particle size is less than 5 microns, the powder is as fine as smoke, and it is easy to adhere to the surface of the crop and the surface of the insect, so that its effect can be fully exerted.
At present, the commonly used powder spraying equipment, the manual dusting machine mainly has Harvest type-5 and Harvest type-10; the motorized duster has Dongfanghong-18 type. When using the duster to dust, in addition to paying attention to uniform spraying, no heavy spraying, no leakage, it should also be noted that the powder should be dry and loose and the duster itself must be kept dry to make the powder have good flowability. In order to achieve uniform distribution and deposition.
3. Granulation application At present, there are two types of granules used in China, such as good immersion granules and coated granules.
Impregnating granules: Mixing pesticides with fillers and adding a certain amount of binder to the pellets. When used, the particles must be disintegrated in order to release all the pesticides contained in the particles, usually under the action of moisture. For example, the application of insecticidal double granules for controlling pests in rice fields and the use of pesticides for the control of corn leaf stalks and granules made of brick or clay.
The coated granule is a granule which is prepared by coating the pesticide on the surface of a filler granule after being treated. Application relies on field water or soil moisture to dissolve the pesticide on the surface of the particles into water and then act, such as carbofuran granules.
The application of granules should be based on the nature of the pesticides, the living habits of the diseases, insects, weeds, the characteristics of the hazards, and the characteristics of the action of the soil and water on the pesticides, in order to be properly selected, and the granules must be applied according to the products. The application method proposed in the instruction manual is carried out.
4. Poison release The use of bait for rodent control is a widely used method of rodent control. There are two main categories of acute rodenticide bait and chronic rodenticide bait. Made with a mixture of pesticides and food (grain or other food).
Chronic rodenticide (anticoagulant rodenticide) bait release: When the rodent is used properly, the poison bait is used properly, and the rodents in the local area can be completely poisoned. The bait is placed as far as possible on the side of the rat, at the mouth of the rat (about 15-30 cm from the opening) and where the rodents are hidden. Feeding in the field depends on the living habits of different species of rats. For example, in the northern part of the hamsters, the bait is mainly invested in the crop field (10 meters wide in the field), and a pile is placed every 1 meter; in the south, the poisonous bait is put in the fields of Kuantianyu and Gaotianyu. More rat holes, the effect is good. Rats like to eat in hidden places, and use bait boxes to feed the bait, whether in the field or indoors, to facilitate the hidden feeding of rats, to protect the bait from moisture deterioration, and to prevent non-target animals from feeding.
Acute rodenticide bait release: In the arable land and grassland where it is easy to find the mouse hole, take the poisoning bait in the hole and cast it at 15-30 cm from the hole, 1-2 grams per hole. In places where it is difficult to find the mouse hole, take etc. From the bait, every 5-10 meters, put a pile of poison bait, 5-6 grams per pile. Indoor annihilation rats, generally a room of about 15 square meters can be put a pile of poison bait, about 25 grams per pile. For example, the small house mouse can increase the feeding point appropriately, and the amount of poison bait should be appropriately reduced.
Regardless of wild rodent control or indoor rodent control, it is necessary to put a poison bait surface to be larger. At least one township or one county has unified actions. Indoor and outdoor, indoor and outdoor, the poison bait is uniformly distributed, and the effect is better than scattered scattered rodent control.
5. Scientific compounding pesticides At present, domestic and foreign pesticides are mixed and mixed. Two or more pesticide preparations containing different active ingredients are mixed and applied together, which is called a mixture of pesticides. A pesticide preparation having two or more active ingredients sold for mixing is referred to as a pesticide mixture preparation. According to its use, it is divided into insecticide mixture, bactericidal mixture, herbicidal mixture, insecticidal and bactericidal mixture, insecticidal and herbicidal mixture.
Rational and scientific mixing of pesticides can improve the control effect, delay the production of resistance by harmful organisms or expand the scope of use to treat different types of pests, save manpower and dosage, reduce costs, improve drug efficiency, reduce toxicity, and enhance safety for humans and animals. Sex. For example, dimethoate and carbaryl can be combined with rice sorghum to enhance the effect; carbendazim is mixed with carbendazim, thiophanate-methyl and sulcoline; BT emulsion and insecticidal double-mixing are used to control rice stem borer and rice. Aphids have synergistic effects.
Not all pesticides can be mixed. For example, organophosphorus pesticides that are decomposed by alkali cannot be mixed with a strong alkaline stone sulphur mixture. Pesticides that can be mixed do not undergo chemical changes between their active ingredients. The fastest growing in recent years is the compound preparation of high-efficiency pyrethroid insecticides and organophosphate insecticides as active ingredients.
For the varieties introduced in this book, which two pesticides can not be mixed and which single agents can only be used alone, before mixing, pay attention to the “unmixable pesticide checklist†(Table 1-5). Do not mix the two pesticides that cannot be mixed together. At the same time, pay attention to the use of two kinds of liquids that can be used in liquid form after dilution. Generally, first dilute one of the drugs with all the water, and then use this. A kind of liquid to dilute a coffee, do not mix the two drugs and then dilute, do not dilute the two drugs and then mix.
At present, there are more than 100 varieties of domestic pesticides registered in China, mostly for the mixture that needs to be commonly used in combination and can be made during the processing of pesticides. However, powders and granules are difficult to mix evenly after temporary application, and aerosols are not convenient for temporary mixing. It is necessary to prepare a styling mixture in advance to facilitate the use.
6. Prevention of disease, insects, and rodent resistance In a region, the use of a pesticide to control the same disease, insect, and mouse, long-term continuous use, often significantly reduced or even ineffective, and easily lead to resistance to harmful organisms. If insecticides and fungicides are used continuously, the resistance of pests and pathogens is more obvious. In the past 70 years, there have been more than 600 kinds of pests that have developed resistance, and there are dozens of types of resistant bacteria. In particular, some pyrethroid insecticides and systemic fungicides have been used continuously for several years, and the control effect has been greatly reduced. Another example is the anti-coagulant rodenticide, rodenticide, and the control of domestic rats. In the early 1950s, the world was widely promoted, and the effect was very significant. However, after several years of continuous use, it was first discovered in the consolidation of Scottish farms in 1958. Hereditary drug resistance has been reported in Denmark, the Netherlands, the Federal Republic of Germany, France, the United States and Australia. By 1960, in the United Kingdom, in the city where rodentin was used, Mus musculus was resistant.
When there is a decline in the efficacy of some medicines, it is necessary to pay attention to investigation and analysis from various aspects to find the exact cause. Because the efficacy of any pesticide, in addition to the virulence level of the drug itself, is subject to a variety of other factors and conditions. Such as natural conditions, temperature and humidity differences, spraying technology, use concentration, whether the bait used to prepare the bait is fresh and palatable, whether the object is controlled, etc., do not easily reach a conclusion.
The prevention of drug resistance is mainly the use of drugs, mixed drugs, intermittent drugs and scientific application techniques.
Rotational medication: Rotation of pesticides with different mechanisms of action is one of the effective ways to delay the emergence of resistance to pests. For example, organophosphorus preparations, pyrethroid preparations, carbamate preparations, organic nitrogen preparations, biological preparations and the like in insecticides have different mechanism of action and can be used alternately; fungicides are generally contact fungicides such as Daisen, inorganic sulfur preparations, and copper preparations are not easy to cause drug resistance, and are better rotatable drugs. It should be noted that general systemic fungicides such as benzimidazole fungicides (carbendazim, thiophanate, etc.) and antibiotic fungicides are relatively easy to cause drug resistance; rodenticides can be used as acute rodenticides and chronic rodenticides. Rotate.
Mixed use: In order to slow down the rate of drug resistance, two kinds of agents with different modes of action and mechanisms are used, such as mixed with methomyl and pyrethroid; disulfidemide is mixed with carbamate and organic phosphorus; organic The phosphorus preparation is mixed with the pyrethroid; the bacterium is mixed with the mancozeb. Mixed pesticides can also be used in a single period of time, and must be rotated, otherwise it will cause drug resistance.
Intermittent medication: Drugs that have developed resistance have been discontinued for a period of time, and drug resistance may gradually decline or even disappear. For example, in the past, the resistance to aphids used in the control of cotton aphid, resistance to aphids, etc., after a period of use, drug resistance has basically disappeared, the virulence of the drug can still be restored.
Scientific and appropriate application techniques: It is also an important measure to apply scientific and appropriate application techniques to different crop fields and pests to make the effective dose and deposition distribution of the agent in the field uniform.
(2) Timely application of the drug The application period should be based on the development period of the pest and the progress of the crop and the variety of the pesticide. All local pest monitoring stations and rodent monitoring stations should conduct annual monitoring, issue forecasts, and develop prevention and control indicators for major diseases, insects and rodents. If the amount of the disease reaches the prevention and treatment index, it should be controlled by the drug. When applying the medicine, you should also consider the situation of natural enemies in the field, and try to avoid the sensitive period of natural enemies to pesticides. For example, in the case of rodent control, the bait should be applied before the breeding peak of the main dominant species of the local species; when the herbicide is applied, it is necessary to look at the grass and look at the "miao" situation, such as using pre-emergence herbicides, and must not be after emergence. use.
(3) Appropriate application of pesticides When using all kinds of pesticides, they should be used according to the recommended dosage of the product introduction manual. Strictly control the dosage, and can not increase or decrease arbitrarily. Otherwise, it will cause crop phytotoxicity or affect the control effect. During the operation, not only the amount of medicine, the amount of water, and the amount of bait, but also the amount of application area, can be accurately applied in an accurate and appropriate amount to achieve good control effects. There are four ways to indicate the amount of application:
1. For the application of the number of preparations, such as the use of 10% Uranus EC 2-2.5 grams per acre to control cotton bollworm, master the amount of medicine used.
2. Use the amount of active ingredients to represent, such as 25% nitrile emulsifiable concentrate, use 2-4 grams of active ingredient per acre to control wheat powdery mildew.
3. Use the ratio of water to the water, such as 5% bactericidal water clearing agent 100-200 times solution to smear apple tree rot disease spots to prevent rot disease.
4. Use a concentration of parts per million of active ingredient. For example, 2.5% Kungfu emulsifiable concentrate is used to control apple tree peaches. For example, 100 parts per million (abbreviated as 100 ppm), that is, 100 parts of kungfu emulsifiable concentrate in 1 million parts of the diluent. 5-6.3 ppm means that there are 5-6.3 Kung Fu emulsifiable concentrates in 1 million dilutions.
(4) Uniform application The application methods of various dosage forms of pesticides are different, and the instruments used are also different. At present, the main types of applicators are spray equipment, dusting machines, granule spreaders, smoke spray machines, seed dressing machines, etc. There are many types of machines in each category. The tools used for various pesticides have their specific uses and properties. When applying, liquid medicine spraying, powder spraying, granule spraying, and poisoning bait input must consider the performance and characteristics of the instruments and implements used. It can play its due role well, so that the agent can be evenly and evenly distributed on the surface of crops or harmful organisms, and scientific and efficient control results can be obtained.
1. Liquid spray The liquid preparation is the largest and most varied dosage form of pesticide preparation. The quality of the spray in the field depends mainly on the performance of the spray equipment used and the skill level of the operators. The liquid preparation is atomized by means of a spray machine to disperse the liquid into small droplets, so that the surface of the crop or the harmful organism can be uniformly covered to achieve an ideal control effect. However, due to the uniformity of the control objects and the hazard crops, the ideal control effect is achieved. However, due to the different types of crops and the types of crops that are harmful, it is necessary to select suitable machines with different properties. The currently widely used workers and peasants 16 type manual sprayers, pedal sprayers, stretcher type motorized sprayers, etc., are all constant sprays. The latter two sprayers, due to high pressure, high range and long range, are suitable for orchards and forest gardens and can be sprayed on the top and inside of the crown. In the crop field, the worker-peasant 16 manual sprayer is used to carry out the top-loading spray. The lower leaves of the wheat field have more medicines, and the upper leaves have less medicine. The effect of controlling the wheat sucking insects and the tubeworms is good, but it is good for controlling wheat scab and wheat ears. Long tube is not very effective. In the cotton field, the upper leaves of the cotton plant received more medicine, while the lower leaves received less medicine, which was effective for the prevention and control of blind mites, and the control of Fuxi was very poor. Therefore, it is necessary to properly select a suitable application machine for uniform application. The pedal type sprayer and the stretcher type motorized sprayer can spray large trees with high pressure. The disadvantage is that the droplets are large, and the liquid medicine is easily lost from the leaf surface. The loss is generally 60%-70%, and the medicament is wasted. Low-volume spray with Dongfanghong 18 mister can save energy compared with high-volume spray, and has high work efficiency. The general liquid area per unit area, the constant (high capacity) is more than 40 liters, and the ultra-low capacity is less than 0.33 liters. Because the Dongfanghong 18 misting machine can generate powerful airflow by itself, it can be used for ultra-low volume spraying under any circumstances; However, using the Eva-type hand-held ultra-low-capacity sprayer spray, the ultra-low-volume spray method has very small droplets, and it is necessary to send the mist to a certain distance under windy conditions, and it can hardly function when there is no wind, so it is used. For the hand-held sprayer spray, it is required to be used when there is natural wind.
When spraying the herbicide, use a special nozzle, the lasing nozzle, to reduce the damage caused by the fine mist. Ultra-low volume spray method requires atomization fineness to reach about 50 microns, and the droplets can drift in the air for a long time and will not fall to the ground very quickly. When using a hand-held low-low-capacity sprayer, you should not use the turntable nozzle to the lower layer of the crop to use it. Otherwise, it will not be able to perform its proper function, but will cause damage to the crop.
2. Powder spray powder is divided into low concentration powder, high concentration powder, anti-flushing powder, ultrafine powder. When using powder, manual or motorized dusting equipment is used. The airflow generated by the duster can blow the powder to spread evenly and form a good deposit on the surface of the plant and on the surface of the insect. This is mainly due to adhesion or electrostatic adsorption. The adhesion is small, but on the surface of the organism with water film, the adhesion ability of the powder can be improved, so the operation of the dusting operation often requires that the early and late crop leaves are wet or dewed. When the wind is strong, the wind speed exceeds 1 meter per second. Do not spray the powder to avoid waste of the powder. The average dosage of the acre is 1500-2000 grams.
Low-concentration powder: It can be sprayed directly in the field.
High-concentration powder: Also known as high-concentration mother powder, it is mixed with a certain fineness of filler during use, and then sprayed.
Anti-flushing powder: It is a kind of powder with larger particle size, or adding coagulant in the powder to polymerize small particles into larger particles to overcome the drift phenomenon when the powder is used.
Ultrafine powder: mainly used in greenhouses, the particle size is less than 5 microns, the powder is as fine as smoke, and it is easy to adhere to the surface of the crop and the surface of the insect, so that its effect can be fully exerted.
At present, the commonly used powder spraying equipment, the manual dusting machine mainly has Harvest type-5 and Harvest type-10; the motorized duster has Dongfanghong-18 type. When using the duster to dust, in addition to paying attention to uniform spraying, no heavy spraying, no leakage, it should also be noted that the powder should be dry and loose and the duster itself must be kept dry to make the powder have good flowability. In order to achieve uniform distribution and deposition.
3. Granulation application At present, there are two types of granules used in China, such as good immersion granules and coated granules.
Impregnating granules: Mixing pesticides with fillers and adding a certain amount of binder to the pellets. When used, the particles must be disintegrated in order to release all the pesticides contained in the particles, usually under the action of moisture. For example, the application of insecticidal double granules for controlling pests in rice fields and the use of pesticides for the control of corn leaf stalks and granules made of brick or clay.
The coated granule is a granule which is prepared by coating the pesticide on the surface of a filler granule after being treated. Application relies on field water or soil moisture to dissolve the pesticide on the surface of the particles into water and then act, such as carbofuran granules.
The application of granules should be based on the nature of the pesticides, the living habits of the diseases, insects, weeds, the characteristics of the hazards, and the characteristics of the action of the soil and water on the pesticides, in order to be properly selected, and the granules must be applied according to the products. The application method proposed in the instruction manual is carried out.
4. Poison release The use of bait for rodent control is a widely used method of rodent control. There are two main categories of acute rodenticide bait and chronic rodenticide bait. Made with a mixture of pesticides and food (grain or other food).
Chronic rodenticide (anticoagulant rodenticide) bait release: When the rodent is used properly, the poison bait is used properly, and the rodents in the local area can be completely poisoned. The bait is placed as far as possible on the side of the rat, at the mouth of the rat (about 15-30 cm from the opening) and where the rodents are hidden. Feeding in the field depends on the living habits of different species of rats. For example, in the northern part of the hamsters, the bait is mainly invested in the crop field (10 meters wide in the field), and a pile is placed every 1 meter; in the south, the poisonous bait is put in the fields of Kuantianyu and Gaotianyu. More rat holes, the effect is good. Rats like to eat in hidden places, and use bait boxes to feed the bait, whether in the field or indoors, to facilitate the hidden feeding of rats, to protect the bait from moisture deterioration, and to prevent non-target animals from feeding.
Acute rodenticide bait release: In the arable land and grassland where it is easy to find the mouse hole, take the poisoning bait in the hole and cast it at 15-30 cm from the hole, 1-2 grams per hole. In places where it is difficult to find the mouse hole, take etc. From the bait, every 5-10 meters, put a pile of poison bait, 5-6 grams per pile. Indoor annihilation rats, generally a room of about 15 square meters can be put a pile of poison bait, about 25 grams per pile. For example, the small house mouse can increase the feeding point appropriately, and the amount of poison bait should be appropriately reduced.
Regardless of wild rodent control or indoor rodent control, it is necessary to put a poison bait surface to be larger. At least one township or one county has unified actions. Indoor and outdoor, indoor and outdoor, the poison bait is uniformly distributed, and the effect is better than scattered scattered rodent control.
5. Scientific compounding pesticides At present, domestic and foreign pesticides are mixed and mixed. Two or more pesticide preparations containing different active ingredients are mixed and applied together, which is called a mixture of pesticides. A pesticide preparation having two or more active ingredients sold for mixing is referred to as a pesticide mixture preparation. According to its use, it is divided into insecticide mixture, bactericidal mixture, herbicidal mixture, insecticidal and bactericidal mixture, insecticidal and herbicidal mixture.
Rational and scientific mixing of pesticides can improve the control effect, delay the production of resistance by harmful organisms or expand the scope of use to treat different types of pests, save manpower and dosage, reduce costs, improve drug efficiency, reduce toxicity, and enhance safety for humans and animals. Sex. For example, dimethoate and carbaryl can be combined with rice sorghum to enhance the effect; carbendazim is mixed with carbendazim, thiophanate-methyl and sulcoline; BT emulsion and insecticidal double-mixing are used to control rice stem borer and rice. Aphids have synergistic effects.
Not all pesticides can be mixed. For example, organophosphorus pesticides that are decomposed by alkali cannot be mixed with a strong alkaline stone sulphur mixture. Pesticides that can be mixed do not undergo chemical changes between their active ingredients. The fastest growing in recent years is the compound preparation of high-efficiency pyrethroid insecticides and organophosphate insecticides as active ingredients.
For the varieties introduced in this book, which two pesticides can not be mixed and which single agents can only be used alone, before mixing, pay attention to the “unmixable pesticide checklist†(Table 1-5). Do not mix the two pesticides that cannot be mixed together. At the same time, pay attention to the use of two kinds of liquids that can be used in liquid form after dilution. Generally, first dilute one of the drugs with all the water, and then use this. A kind of liquid to dilute a coffee, do not mix the two drugs and then dilute, do not dilute the two drugs and then mix.
At present, there are more than 100 varieties of domestic pesticides registered in China, mostly for the mixture that needs to be commonly used in combination and can be made during the processing of pesticides. However, powders and granules are difficult to mix evenly after temporary application, and aerosols are not convenient for temporary mixing. It is necessary to prepare a styling mixture in advance to facilitate the use.
6. Prevention of disease, insects, and rodent resistance In a region, the use of a pesticide to control the same disease, insect, and mouse, long-term continuous use, often significantly reduced or even ineffective, and easily lead to resistance to harmful organisms. If insecticides and fungicides are used continuously, the resistance of pests and pathogens is more obvious. In the past 70 years, there have been more than 600 kinds of pests that have developed resistance, and there are dozens of types of resistant bacteria. In particular, some pyrethroid insecticides and systemic fungicides have been used continuously for several years, and the control effect has been greatly reduced. Another example is the anti-coagulant rodenticide, rodenticide, and the control of domestic rats. In the early 1950s, the world was widely promoted, and the effect was very significant. However, after several years of continuous use, it was first discovered in the consolidation of Scottish farms in 1958. Hereditary drug resistance has been reported in Denmark, the Netherlands, the Federal Republic of Germany, France, the United States and Australia. By 1960, in the United Kingdom, in the city where rodentin was used, Mus musculus was resistant.
When there is a decline in the efficacy of some medicines, it is necessary to pay attention to investigation and analysis from various aspects to find the exact cause. Because the efficacy of any pesticide, in addition to the virulence level of the drug itself, is subject to a variety of other factors and conditions. Such as natural conditions, temperature and humidity differences, spraying technology, use concentration, whether the bait used to prepare the bait is fresh and palatable, whether the object is controlled, etc., do not easily reach a conclusion.
The prevention of drug resistance is mainly the use of drugs, mixed drugs, intermittent drugs and scientific application techniques.
Rotational medication: Rotation of pesticides with different mechanisms of action is one of the effective ways to delay the emergence of resistance to pests. For example, organophosphorus preparations, pyrethroid preparations, carbamate preparations, organic nitrogen preparations, biological preparations and the like in insecticides have different mechanism of action and can be used alternately; fungicides are generally contact fungicides such as Daisen, inorganic sulfur preparations, and copper preparations are not easy to cause drug resistance, and are better rotatable drugs. It should be noted that general systemic fungicides such as benzimidazole fungicides (carbendazim, thiophanate, etc.) and antibiotic fungicides are relatively easy to cause drug resistance; rodenticides can be used as acute rodenticides and chronic rodenticides. Rotate.
Mixed use: In order to slow down the rate of drug resistance, two kinds of agents with different modes of action and mechanisms are used, such as mixed with methomyl and pyrethroid; disulfidemide is mixed with carbamate and organic phosphorus; organic The phosphorus preparation is mixed with the pyrethroid; the bacterium is mixed with the mancozeb. Mixed pesticides can also be used in a single period of time, and must be rotated, otherwise it will cause drug resistance.
Intermittent medication: Drugs that have developed resistance have been discontinued for a period of time, and drug resistance may gradually decline or even disappear. For example, in the past, the resistance to aphids used in the control of cotton aphid, resistance to aphids, etc., after a period of use, drug resistance has basically disappeared, the virulence of the drug can still be restored.
Scientific and appropriate application techniques: It is also an important measure to apply scientific and appropriate application techniques to different crop fields and pests to make the effective dose and deposition distribution of the agent in the field uniform.
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