How to choose pesticides do you know?
What are pesticides?
The broad definition of pesticides refers to chemical synthesis or a substance or a mixture of several substances and its preparations that are used to prevent, eliminate or control diseases, insects, grasses and other harmful organisms that endanger agriculture and forestry, as well as to regulate, control, and affect the metabolism, growth, development, and reproduction of plants and harmful organisms. In a narrow sense, it refers to a class of drugs used to kill insects, bacteria, and harmful animals (or weeds) to ensure and promote the growth of plants and crops in agricultural production. Specifically refers to pesticides used in agriculture to control diseases and insect pests, regulate plant growth, and kill weeds.
Classification of pesticides
Classification according to prevention objects
Insecticides, fungicides, acaricides, nematicides, rodenticides, herbicides, defoliants, plant growth regulators, etc.
Classification according to processing dosage form
Wettable powder, soluble powder, emulsion, emulsifiable concentrate, concentrated emulsion, cream, paste, colloid, fumigant, fumigant, aerosol, oil, granule, microparticle, etc.
Classification according to chemical composition
1. Inorganic pesticides
Inorganic pesticides are pesticides obtained from natural minerals. Inorganic pesticides come from nature, have good environmental solubility, and are generally less toxic to humans. They are currently strongly advocated for use; they can be used in the production of pollution-free food, green food, and organic food; inorganic pesticides include inorganic insecticides, inorganic fungicides, and inorganic herbicides, such as lime sulfur, sulfur powder, and Bordeaux mixture. Inorganic pesticides generally have small molecular weight and poor stability, and most of them should not be mixed with other pesticides.
2. Biological pesticides
Biopesticides refer to products that use organisms or their metabolites to control pests and diseases. Biopesticides are very specific and generally only work against one or a certain type of pests. They are non-toxic or have very little toxicity to humans. They are also highly advocated and popularized pesticides at present; they can be used in the production of pollution-free food, green food, and organic food; biopesticides include fungi, bacteria, viruses, nematodes, etc. When using biological pesticides, live bacteria pesticides should not be mixed with fungicides and pesticides containing heavy metals, and try to avoid spraying in strong sunlight.
3. Organic pesticides
Organic pesticides include natural organic pesticides and synthetic pesticides
(1) Natural organic pesticides are organic substances from nature, have good environmental solubility, and are generally less toxic to humans. They are currently strongly advocated for use; they can be used in the production of pollution-free food, green food, and organic food. Such as botanical pesticides, horticultural spray oil, etc.
(2) Synthetic pesticides are synthetic chemical pesticides; there are many types and complex structures, most of which are polymer compounds; the pH is mostly neutral, and most are easy to decompose under strong alkali or strong acid conditions; There are mainly 5 categories:
1) Organic pesticides: including organophosphates, organochlorines, carbamates, pyrethroids, specific insecticides, etc.
2) Organic acaricides: including specific tin-containing organic acaricides and non-tin organic acaricides.
3) Organic fungicides: including dithiocarbamates, phthalimides, benzimidazoles, dicarboximides, organophosphorus, phenylamides, sterol biosynthesis inhibitors, etc.
4) Organic herbicides: including phenoxycarboxylic acids, triazines, substituted urines, carbamates, amides, benzoic acids, diphenyl ethers, dinitroanilines, organophosphorus, sulfonylureas, etc.
5) Plant growth regulators: mainly auxins, gibberellins, cytokinins, etc.
Dosage Form of Pesticide
1. Powder. The powder is not easily soluble in water, and generally cannot be sprayed with water. The low-concentration powder is used for dusting, and the high-concentration powder is used to prepare poisonous soil, poison bait, seed dressing and soil treatment. The powder is easy to use and has high work efficiency. It should be used in the morning and evening when there is no wind or the wind is weak.
2. Wettable powder. Strong hygroscopicity, can be dispersed or suspended in water after adding water. It can be used as spray, poison bait and soil treatment.
3. Soluble powder (water solvent). It can be sprayed or poured directly on water.
4. Emulsion (also known as EC). After adding water, the emulsion becomes an emulsion, which can be used for spraying, pouring, seed dressing, soaking, poisonous soil, and coating stems, etc.
5. Ultra-low volume formulations (oil formulations). It is a medicament directly used for spraying, and it is a special matching pesticide for ultra-low volume spraying. Water cannot be added when using it.
6. Granules and microgranules. It is a pesticide dosage form made of pesticide raw materials and fillers, which is not easy to cause phytotoxicity. It is mainly used for filling heart leaves, spreading, point application, seed dressing, furrow application, etc.
7. Sustained release agent. Pesticides are released slowly during use, which can effectively prolong the drug effect period. Therefore, the residual effect period is extended, and pollution and toxicity are reduced, and the usage is generally the same as that of granules.
8. Smoke agent. Smoke agent is a fine powder or ingot made of pesticides, fuels, oxidizers, combustion enhancers, etc. This type of pesticide is vaporized by heat, and then condenses into solid particles in the air to form smoke. It is mainly used to control forest, facility agricultural diseases and pests and warehouse pests.
How to use pesticides
1. Spray
Spraying is to spray the medicinal liquid evenly on the control objects and protected host plants by means of spraying equipment. It is the most widely used method in production at present. The formulations suitable for spraying include emulsifiable concentrates, wettable powders, soluble powders, and suspensions. When spraying, the size of the spray droplets will affect the control effect. Generally, the diameter of the spray on the ground is preferably between 50-80 μm, and the spraying is required to be even and thoughtful. It is best not to choose noon when spraying to avoid drug damage and human poisoning.
2. Dusting
Dust spraying is a pesticide application method that uses the wind generated by dusting equipment to evenly spray powder on the target plants. This method is most suitable for use in arid and water-deficient areas. The dosage form suitable for dusting is powder. The disadvantage of this method is that the dosage is large, the adhesion of the powder is poor, the effect is not as good as the emulsifiable concentrate and wettable powder of the medicine, and it is easy to be lost by wind and rain, polluting the environment. Therefore, when spraying powder, it is easy to carry out in the morning and evening when there is dew on the leaf surface or the leaf surface is wet and calm after rain, so that the powder is easy to deposit and adhere to the leaf surface and improve the control effect.
3. Soil treatment
It is to mix the medicinal powder with fine soil, fine sand furnace ash, etc., spread it on the ground, and then plow it with a columbine rake, etc. It is mainly used to control underground pests or insects that move on the ground during a certain period. For example, mix 1 part of 5% phoxim granules with 50 parts of fine soil to make poisonous soil.
4. Seed dressing, soaking or soaking seedlings, stuffing
Seed dressing refers to mixing a certain amount of medicinal powder or medicinal liquid with seeds before sowing to prevent and control seed-borne diseases and underground pests. The dosage for seed dressing is generally 0.2%-0.5% of the weight of the seeds. Soaking seeds or soaking seedlings is to soak seeds or seedlings in a certain concentration of medicinal liquid to eliminate germs or insects carried by seedlings. Smothering is to spread the seeds on the ground, spray the diluted medicinal solution evenly on the seeds, and stir them evenly, then pile them up and cover them with sacks, etc. After a period of time, they can be dried in the air.
5 poison valley, poison bait
The bait that pests like to eat is mixed with pesticides to lure pests to come to eat, and produce stomach poisoning to kill pests. Commonly used baits include wheat bran, rice bran, bean cake, peanut cake, corn cob, vegetable leaves, etc. The bait is evenly mixed with stomach poisons such as trichlorfon and phoxim, and spread in places where pests are active. It is mainly used to prevent and control underground pests such as mole crickets, cutworms, and crickets. Poisonous grains use grains such as millet, sorghum, and corn as bait. Then simulcast with seeds or spread on the ground.
6. Fumigation
Fumigation is the use of toxic gases to kill pests or germs. Generally, it should be carried out under airtight conditions. It is mainly used to control pests in greenhouses, warehouses, borers and seedlings. For example, fumigate beetle larvae with zinc phosphide poison swab, and fumigate aphids in greenhouses with dichlorvos.
Choose pesticides according to the control object
Determine which kind of pest and weed pest is the control object, and choose the appropriate pesticide according to the label.
Choose pesticides according to the characteristics of pest damage
For example, to control caterpillars and other chewing mouthparts pests that harm leaves, stomach poisons or contact killers should be selected; to control sucking mouthparts such as aphids, insecticides with strong systemic properties should be selected; to control natural and other moth pests, insecticides with strong fumigation effects should be selected.
Selecting Pesticides According to the Occurrence Law of Pests and Diseases
For example, in the initial infection stage of the disease, a fungicide with a protective effect should be selected; when the pathogen invades the host, a systemic fungicide should be selected; for diseases with long infection period and latent infection characteristics (such as resin disease and canker disease), it is necessary to choose a fungicide that has both therapeutic and protective effects.
Select pesticides according to biological characteristics of pests and diseases
For example, when controlling pests such as fruit flies, flower bud maggots and gillworms that overwinter in the soil, spray pesticides on the ground during the unearthed period of pests in spring, and choose insecticides with strong contact killing properties, and spray pesticides on trees during the adult egg-laying period, and choose insecticides that have both contact and stomach poisoning effects. To prevent borer pests, fumigants should be used to prevent larvae bored into the branches and sprayed in the borers; to prevent adults or eggs, contact killers should be used and sprayed on the trunk.
Select pesticides according to their characteristics
Various pesticides have a certain scope of application and application period. For example, the control effect of propargite in summer is significantly higher than that in spring. Some pesticides are effective against a certain developmental stage of pests, but have poor control effects on other developmental stages. For example, hexythiazox has a good control effect on eggs of harmful mites, but poor control effect on active mites. Insect growth regulator insecticides such as diflubenzuron can only show a good control effect when used in the young larvae stage.
The price of pesticides
Usually, the price of pesticides will be affected by raw materials, market environment, research and development costs, etc. If you want to know the latest price of the pesticide you need, please contact us to initiate an inquiry
Tel: 13563082345 Email: sales@agripesticide.com
Supplier of pesticides
Agripestcide is aprofessional agrochemical manufacturer, providing herbicides, insecticides, microbial fungicides, plant growth regulators and other products.
Precautions when using pesticides
1. The use of pesticides in windy days: Generally, powdered pesticides and sprayed pesticides will be affected. Pesticides are easily blown away by strong winds, reducing the efficacy of pesticides and failing to achieve the effect. Moreover, pesticides can easily cause environmental pollution as the wind spreads. When spraying powder in strong winds, the wind speed should not exceed 1 m/s; for low-volume spray, the wind speed should not exceed 5 m/s; for ultra-low-volume spray, the wind speed should not exceed 1-3 m/s.
2. Use pesticides on rainy days: Pesticides are easily washed away by rainwater, or rainwater dilutes pesticides, which cannot achieve the expected effect. Pesticides flowing into the soil may also cause environmental pollution.
3. Spray pesticides during high temperature and hot time: Pesticides are easily volatilized and decomposed, affecting the effect of pesticides, and may even cause poisoning of pesticide applicators. The general spraying temperature is suitable for 20-30 ℃.
4. Dilute pesticides with well water: Well water contains a lot of calcium and magnesium substances. Diluting pesticides with well water will destroy the emulsification and suspension properties of the pesticides, reduce or even completely lose the efficacy of the pesticides, which not only affects the control effect, but also easily causes phytotoxicity.
5. Use wettable powder for pesticide spraying: wettable powder is a powder made by adding a certain amount of wetting agent and filler to the original drug and mechanically milling or jet milling. Compared with general powder, it has high active ingredient content and poor fluidity. Therefore, it can only be used as a suspension after dissolving in water, and it is not allowed to be sprayed directly as a powder.
6. Use granule pesticide immersion spray: The specifications and composition of granule pesticide are mostly developed and produced according to the biological characteristics of its control objects and protected objects and the environmental conditions of the application site, so it has strong specificity, special effects and targeted delivery; currently it is mainly used for ground and underground application of pesticides to prevent weeds or pests, and water spraying is not allowed. In addition, most of the original drugs used in the production of granules are highly toxic pesticides. After granulation treatment, the toxicity is reduced, which can increase the safety of use; water immersion and spraying will make the toxicity return, and it is easy to cause poisoning of the applicators during use.
7. Use highly toxic pesticides for ultra-low-volume spraying: Since ultra-low-volume spraying has a higher concentration of liquid medicine than conventional spraying, it can only be limited to spraying less toxic pesticides, such as pyrethroid pesticides, etc., and the sprayers must always stand in the up-and-coming drug-free rows. It is forbidden to use highly toxic pesticides for ultra-low-volume spraying to avoid productive poisoning.
Pesticides are widely used in prenatal and postnatal agricultural production, effectively increasing the output of crops in the world by 3 times and making great contributions to the development of agriculture. At the same time, pesticides are a double-edged sword and pose a serious threat to environmental health. The negative effects of pesticides have gradually been recognized by people, such as irrational use of pesticides, poisoning of humans and animals, environmental pollution, killing of beneficial organisms, destruction of ecological balance, insect resistance, plant damage, and excessive pesticide residues.
The development of pesticides has never been smooth sailing. When problems arise during the development process, people will deal with the problems by banning and restricting measures or developing new pesticides. Generally speaking, the development of pesticides shows a spiral upward process, and the safety of modern pesticides is constantly improving, but it is still impossible to avoid the characteristics of toxic chemicals. Therefore, people's concept of pesticides has gradually changed, from emphasizing killing harmful organisms, to regulating and repelling harmful organisms, and regulating crop growth. The most ideal pesticide should be a pesticide that is harmonious with the environment. It should have the following characteristics: safe and harmless to human health, environmentally friendly, high selectivity, low dosage, and green production process. In this way, man and nature can develop in harmony, pesticides have changed from simple killing to active regulation, and human pest control has moved from the "kingdom of necessity" to the "kingdom of freedom".