In the production of pollution-free vegetables, the use of pesticides has always been a "double-edged sword". How can we achieve the goal of killing pests and germs while ensuring the safety of agricultural products? It is the focus of the majority of agricultural producers. In this issue, we invited Zhang Linhua, a senior agronomist at the Jintan Plant Protection and Phytosanitary Station, to give us a comprehensive introduction.
In order to enable the majority of vegetable farmers to learn the knowledge of pesticides, the rational use of pesticides, and the effective prevention and control of vegetable pests and diseases, it is of great significance to obtain high-quality, high-yield, pollution-free vegetables.
I. Pesticides and their properties
1. According to raw material source
(1) Organic pesticides: These pesticides are composed of carbon compounds and are mainly made of organic synthetic raw materials such as benzene, alcohols, fatty acids, organic amines, etc. Therefore, they are also called synthetic pesticides such as trichlorfon, carbendazim, etc. . Organic pesticides can be produced industrially, with many varieties, high efficacy, wide use, low phytotoxicity, various processing agent types and modes of action, and currently account for more than 90% of the total pesticides, which occupies an important position in the development of pesticides. (2) Inorganic pesticides: mainly made of natural mineral raw materials, also known as mineral pesticides. These pesticides are characterized by a stable chemical nature, are not easily decomposed, and are insoluble in organic solvents. However, they have fewer varieties, they are relatively simple in function, and they are prone to phytotoxicity. Therefore, their use is limited. (3) Botanical Pesticides: This is a pesticide made from plants as a raw material and solvent-extracted. The active ingredient is a natural organic substance. Its performance is similar to that of organic pesticides, such as pyrethrum and tobacco. Plant pesticides have the advantages of safety to humans and animals, no harm to plants, and availability of materials on the spot. (4) Microbial pesticides; These are pesticides made from microorganisms and their metabolites. The active substances contained are bacterial spores, fungal spores, viruses or antibiotics.
Such as insects, Beauveria bassiana, Bacillus thuringiensis and so on. These pesticides have high efficacy and selectivity, do not harm natural enemies when used, are non-toxic to humans and livestock, and are safe to plants. They are not easy to produce drug resistance in long-term use, but their application range is not wide enough and their functions are relatively slow. Seasonal and environmental factors and other conditions.
2. Classified by purpose and mode of action
(l) Insecticides and acaricides: According to the ways in which pesticides enter the body of insects, they can be divided into contact poisons, stomach poisons, fumigants and internal absorbents. 1 contact killing agent: the agent penetrates into the body from the insect body wall and produces a toxic effect called contact killing effect. The contact-killing agents are called contact killers such as chalcone, phoxim, and rattan.
2 stomach poisons: pharmaceuticals from the pest's digestive system into the body and produce toxic effects, known as stomach poisoning.
Gastrointestinal drugs, called stomach poisons, such as trichlorfon, insecticidal double and so on. (3) Fumigant: The agent is in an aerosol state and is a poison that causes the harmful insects to enter the body through the respiratory system. Such as aluminum phosphide, zinc phosphide and so on. Both can release phosphine gas to kill pests. 4 Inhalants: The pesticides are applied to the stems and leaves or roots of plants, which are absorbed by the plants and transported throughout the plant body. The pests feed the plants and thus produce toxic pesticides.
Such as monocrotophos, dimethoate and so on. (2) ovicidal agents: Pharmacies that can prevent the development of embryos in eggs so that larvae or cockroaches cannot hatch, such as bufalin and amitraz. (3) Bactericides: According to the role of anti-bacterial agents, they can be divided into the following three main types.
1Protective agent; The agent is sprayed on the surface of the plant before the plant is infected to kill or stop the germs or pathogens from impregnating the plants. The currently used bactericides are mostly protective agents, such as Bordeaux mixture, zearalenium, chlorothalonil, and sulfuric acid preparations. The use of such agents tends to be less effective after the onset of the disease. 2 Therapeutic agents: Medications that have a therapeutic effect on diseases, such as Trichoderma and Formamide. Pharmaceutical treatment of diseases is much more difficult than chemical protection. This is because after germs invade, they have a close relationship with the plants and enhance the resistance of the bacteria to the medicine. Generally killing the dose of immersed bacteria will often cause phytotoxicity to the plant. Therefore, the use of therapeutic agents is currently far less widespread than protective agents. Therapeutic agents are only used as a last resort. 3 Inhalants: Medicaments that are absorbed by the leaves, stems, and roots of the plant, enter the plant, and transmit, retain, or produce metabolites in the body to protect the plant from pathogens or to treat plant diseases. Such as the enemy rust sodium, carbendazim, enemy grams pine and so on. Since the adventitious agent was introduced, it has played a prominent role in the prevention and control of plant diseases, but there are also problems that pathogens are susceptible to such agents. Therefore, in recent years, people have attached great importance to the preparation of a protective agent and a systemic admixture or mixed use. In addition to the above types of pesticides, there are acaricides, nematicides, rodenticides, herbicides, plant growth regulators, etc.
1. Give priority to biological pesticides
Commonly used in the production of biological insecticide acaricide: Bt, avermectin, Liuyangmycin, Huaguangmycin, anisanasin, rotenone, matrine, veratrine, etc.; fungicides: Jinggangmycin, Chunlei Antimycin, polyoxin, Wuyimycin, agricultural streptomycin and so on.
2.
The rational selection of chemical pesticides is strictly prohibited the use of highly toxic, highly toxic, high residue, high bio-rich collective, high-tertiary (teratogenic, carcinogenic, mutagenic) pesticides and their complex formulations. Such as methamidophos, carbofuran, 1605, 3911, omethoate, insecticidal cockroaches, methicillin, 666, DDT, methylisophos, aldicarb, methomyl, zinc phosphide, monobloc Phosphorus, organic mercury preparations, etc. Some pesticide residues, such as dicofol, are decomposed slowly and remain in the crop after one year. It is also not suitable for use on vegetables.
The second is to select highly efficient, low-toxic, low-residue chemical pesticides. The production of pollution-free vegetables allows the use of restricted chemical pesticides in a restricted manner. The quality of toxic residues in vegetables does not exceed the national hygiene standards. The metabolites in the human body are harmless and can be easily eliminated from the human body. The lethality to natural enemies is small. . Limited use of chemical insecticidal acaricides are trichlorfon, phoxim, dichlorvos, chlorpheniramine, cypermethrin, deltamethrin, fenvalerate, konjac, shuangmi mic, nisolon,蚜 fog, butoprosumab, diflubenzuron, diflubenzuron, buprofezin and so on. Limited use of chemical fungicides: Bordeaux fluid, DT, chlorambucil, carbendazim, chlorothalonil, thiophanate-methyl, zeinzin, phosphine-aluminum, metalaxyl, trisodium phosphate and the like.
Third, the use of pesticides
1. The right medicine is based on a thorough understanding of pesticide performance and methods of use; according to the type of pest control, use the appropriate pesticide type or dosage form. For example, the stomach poison in pesticides is effective in preventing chewing mouthpart pests, and the pests that prevent sucking mouthparts are ineffective; Buprofezin has a special effect on whiteflies and nymphs and is ineffective against aphids;蚜 特 特 特 特 特 特 特 特 特 特 特 特 特 特 特 特 特 特 特 特 特 特 特 特 特 特 特 特 特 特 特 特 特 特 特 特 特 特 甲 甲 甲 甲 甲 甲 甲 甲 甲 甲 甲 甲 甲 甲 甲 甲 甲 甲 甲 甲. In the prevention and control of pests and diseases in protected areas, different types of pesticides can be flexibly selected according to weather conditions. Powders, wettable powders, and suspensions can be sprayed on sunny days. Cloudy sprays, dust sprays, or smoke can be used on cloudy days without adding sheds. The humidity in the room reduces the amount of leaf dew and leaf edge spit, which has a significant effect on the control of low temperature and high humidity.
2. Appropriate period of medication According to the occurrence of pests and diseases, strictly control the best period of prevention and treatment, timely medication. If the vegetables are planted or planted, measures such as pesticide application in the greenhouse, soil treatment, and seed dressing, etc. should be taken. When spotting of aphids and moths occurs and low density of whitefly occurs, local application is used. Different pesticides have different properties and the control period is not the same. Biological pesticides have a slower effect and should be used 2 to 3 days earlier than chemical pesticides.
3. The scientific use of drugs should pay attention to alternate rotation of pesticides using different mechanisms of action, can not be long-term simplification, to prevent the emergence of drug resistance of pathogens or pests, help maintain the control effect and the use of drugs. In the early stage of vegetable growth, high-efficiency and low-toxicity chemical pesticides and biopesticides are mixed or used alternately. In the later growth stage, biological pesticides are the main components. Use pesticides should promote low-volume spray method, and pay attention to uniform spraying.
4. Select the right spray point or site when the application of pesticides according to the characteristics of different periods of the occurrence of pests and diseases to determine the different parts of the plant as a target for targeted drug application. To achieve timely control of pests and diseases, reduce pathogens and reduce the number of insects to reduce the use of drugs. For example, late blight usually occurs on the front (southern end) crop of the greenhouse first, so it is necessary to spray pesticide on the front crop in time. The occurrence of downy mildew is started from the lower leaf, and the focus of early prevention and control of downy mildew is on the lower leaf, which can reduce the upper leaf disease. Insects such as aphids and whitefly are easy to inhabit the back of young leaves, so they must be evenly sprayed, and the spray heads should be upward, with the focus on the back of the leaves.
5. The rational use of mixed drugs using mixed methods can achieve the purpose of controlling pesticides and pests in a single application. However, pesticides must be mixed to maintain the original active ingredients or synergistic effect, without increasing the toxicity to humans and animals. Good physical properties are prerequisites. Generally neutral pesticides can be mixed; neutral pesticides and acidic pesticides can be mixed; acidic pesticides can be mixed; alkaline pesticides can not be mixed with other pesticides; microbial pesticides (such as Bt) can not be the same with fungicides Highly absorbing pesticides are mixed; mixed pesticides should be used with mixing. When using various bio-sourced pesticides that are mixed with chemical pesticides, the compounded chemical pesticides can only be chemical pesticides that are allowed to be used in limited quantities.
6. Do not arbitrarily increase the amount of medication and the number of spraying times. The guidelines for the safe use of pesticides and the standards for the production of pollution-free vegetables stipulate that each pesticide should be used in different vegetables.
The amount of drugs used, the number of medications, the maximum allowable residue, and the safety interval must be strictly enforced in the production of pollution-free vegetables. It is necessary to thoroughly change the backward habit of increasing the dosage, the frequency of spraying, and the confusion of various pesticides. . The safety interval of pyrethroid pesticides was 5-7 days, organophosphorus pesticides 7-14 days, fungicide chlorothalonil, dexamethasone zinc, carbendazim for more than 14 days, and the remaining 7-10 days. The pesticide mixture performs safety intervals in which the most active ingredients remain. After the pesticide is sprayed on the vegetables, the pesticide must be degraded to no residue. Vegetables harvested many times must be sprayed after harvesting to ensure the health of consumers.
Oxygen Cylinder Filling System
With PSA principles, ETR Oxygen Cylinder Filling system can produce 93%±3% purity oxygen gas from compressed air directly. ETR oxygen cylinder filling system is consisted of Atlas screw air compressor, refrigerated air dryer, compressed air filter, air buffer tank, ETR Oxygen Plant, oxygen buffer tank, oxygen booster, cylinder filling station and HMI control cabinet.
Compressed air is purified through the air dryer and filters to a certain level for main plant to work with. Air buffer is incorporated for smooth supply of compressed air thus to reduce fluctuation of compressed air source. The plant produces oxygen with PSA (pressure swing adsorption) technology, which is a time proven oxygen generation method. Oxygen of desired purity at 93%±3% is delivered to oxygen buffer tank for smooth supply of product gas. Oxygen in buffer tank is maintained at 4bar pressure. With an oxygen booster, the oxygen pressure can be to 150bar and fill in cylinders.
Onsite Oxygen Cylinder Filling System
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