By chemical composition, there are three main groups of pesticides:
- Inorganic compounds (compounds of mercury, fluorine, barium, sulfur, copper, as well as chlorates and borates).
- Preparations of plant, bacterial and fungal origin (pyrethrins, bacterial and fungal preparations, antibiotics and phytoncides).
- Organic compounds are the most extensive group to which pesticides of high physiological activity belong.
The following classes of organic pesticides are distinguished.:
Depending on the purpose and area of use, the following main groups of pesticides are distinguished:
- Acaricides - to fight ticks,
- Algaecides - for destruction of vegetation in reservoirs,
- Antihelminths - to combat the parasitic worms of animals,
- Antiresistants - special additives that reduce the resistance (resistance) of insects to individual substances,
- Antiseptics - to protect wooden and other non-metallic materials from destruction by microorganisms,
- Arboricides - to destroy unwanted shrubs and woody vegetation,
- Attractants - to attract insects,
- Aphistides - to combat aphids,
- Bactericides - to combat bacteria and bacterial diseases of plants,
- Gametocides - substances that cause sterility of weeds,
- Herbicides - for weed control,
- Desiccants - for pre-harvesting of plants,
- Defoliants - to remove the leaves,
- Zoocides - to combat harmful animals,
- Insecticides - to combat insect pests,
- Insectoacaricides - to fight simultaneously with harmful insects and mites,
- Larvicides - to destroy insect larvae and caterpillars,
- Molluscicides or limacids - to combat various mollusks, including gastropods,
- Nematicides - to fight roundworms (nematodes),
- Ovicides - for destruction of eggs of ticks and insects,
- Seed disinfectants - for presowing seed treatment,
- Racicides - to fight rats,
- Plant growth regulators - substances affecting the growth and development of the plant,
- Repellents - to repel harmful insects,
- Retardants - to slow down plant growth,
- Rodenticides - for rodent control,
- Synergists - substances that enhance the action of pesticides,
- Pheromones - substances, producers of insects to affect individuals of the opposite sex,
- Fumigants - substances that are used in a gaseous state to control pests and plant pathogens,
- Fungicides - to combat plant diseases,
- Chemosterilizers - for sexual sterilization of insects.
The classification according to the objects of application is rather arbitrary, since many pesticides have a universal effect and affect both insects and larvae and ticks. For example, malathion is both an insecticide and an acaricide. The term is applicable to this active substance. insectoacaricide.
Method of penetration and mechanism of action
Classification of pesticides according to their ability to penetrate into the organism of the pest, the nature and mechanism of action:
Insecticides and some other pesticides are divided into:
- Contact - causing the death of a harmful object upon contact of the drug with any part of it,
- Intestinal - causing poisoning of harmful organisms when the active substance is ingested with food in their intestines,
- Systemic - able to move through the vascular system of the plant and cause poisoning of insects eating it,
- Fumigants - acting on pests in the form of gas, through their respiratory organs.
Fungicides the nature of the action on pathogens and methods of penetration into plants are divided into two types:
Herbicides by the nature of the impact on the plant are divided into:
- electoral (or selective) that act only on certain plant species (weeds) and are relatively safe for other (cultivated) species,
- solid substance (or general destructive action), destroying all vegetation.
Description of milestones pesticide formulations.
Pesticide Classificationbased on different principles; several different classifications of pesticides are known; They are divided into groups depending on the chemical composition, purpose, route of entry into the body, the degree of danger, etc.
Pesticide Classification by chemical composition:
1. Inorganic pesticides
- copper compounds (mainly insect fungicides - blue vitriol, Bordeaux liquid)
- arsenic compounds (intestinal insecticides, zoocides, preservatives - arsenic anhydride, calcium arsenite, Parisian (Swissfour) greens)
- phosphorus compounds (zoocides - zinc phosphide)
- salts of halogen-containing acids (sodium and potassium chlorates (herbicides of continuous action), magnesium and calcium chlorates (defoliants), sodium fluoride and hydrofluoric acid (antiseptics, insecticides, zoocides)
- sulfur and polysulfides Ca, Ba (acaricides, fungicides)
- sulfuric acid and its compounds (herbicides of continuous action, defoliants, desiccants)
2. Organic Pesticides
1. Organochlorine pesticides (OCPs)
- DDT group (insecticides)
- hexachlorocyclohexane group (insecticides)
- polychlorocyclodienes group (insecticides and plant growth stimulants)
2. Derivatives of phenols (insecticides, fungicides, herbicides, bactericides)
3. Derivatives of carbamic acid (herbicides)
4. Derivatives of aryloxycarboxylic acid
5. Organophosphorus compounds - phosphate esters
- Thiophosphoric esters (metaphos, thiophos)
- dithiophosphoric acid esters (carbafoss, phalaphos)
- amides of pyrophosphoric acid (oxamethyl)
- phosphonate esters (chlorophos)
- Phosphoric esters (dichlorvos)
6. Organic Mercury Compounds - Ethyl Mercurcloride (seed treater)
7. Pyrethroids - derivatives of cyclopropanecarboxylic acids
8. Triazine derivatives (atrazine, simazine)
9. Natural pesticides (insect fungicides)
Pesticide Classification by purpose (by objects of application):
- acaricides - to fight herbivorous mites,
- algaecides - for the destruction of algae and other weeds in reservoirs,
- anthelmintic - to combat parasitic worms in animals,
- antiresistants - special additives that reduce the resistance of insects to individual substances,
- antiseptics - to protect wooden and other non-metallic materials from destruction by microorganisms,
- arboricides - to destroy unwanted tree and shrub vegetation,
- attractants - to attract insects,
- scarcity - to combat aphids,
- bactericides - to fight bacteria and plant bacterial diseases,
- gametocides - substances causing sterility of cultivated plants and weeds,
- herbicides - for weed control,
- desiccants - for pre-harvesting of plants,
- defoliants - to remove the leaves,
- zoocides or rodenticides - for rodent control.
- insecticides - to combat insect pests,
- insectoacaricides - to fight simultaneously with harmful insects and mites,
- laureate - to destroy insect larvae and caterpillars,
- limacids or mollusconids - to combat various mollusks, including the anthropods,
- nematocides - to fight roundworms (nematodes),
- ovicides - for the destruction of eggs of harmful insects and mites:
- seed disinfectants - for presowing seed treatment,
- plant growth regulators - substances affecting the growth and development of plants,
- repellents - to repel harmful insects,
- retardants - to inhibit plant growth,
- synergists - additives that enhance the action of pesticides,
- pheromones - substances produced by insects to affect individuals of the opposite sex,
- fumigants - substances used in the vapor and gaseous state for the destruction of pests and pathogens of plants,
- fungicides - to combat fungal plant diseases caused by various fungi,
- chemo sterilizers - for chemical sexual sterilization of insects.
The classification by purpose (objects of application) is, to a certain extent, conditional, since many pesticides have universality of action and affect both insects - imago and larvae and ticks, and some herbicides can destroy trees and shrubs with increasing doses.
Pesticide Classification depending on how insects enter the body:
- Contact - killing insects in contact with any part of the body
- Intestinal - penetrating the body through the digestive tract
- Systemic - making plants for a certain period poisonous and “food” killing insects
- Fumigants - penetrating through the respiratory tract
Pesticide Classification on the accumulation (cumulation) of them in the body
The basis is the cumulation coefficient K, which is the ratio of the total dose that causes the death of animals during repeated exposure, to LD50 after a single injection, the smaller K, the more dangerous the substance.
"Classification of pesticides according to their accumulation (cumulation) in the body"
Classification of herbicides, the concept
The exact translation of the herbicide from Latin means "grass killer."
Accordingly, the name implies that herbicides are used to kill weeds.
Characteristics of the impact on plants of herbicides are divided into:
- Herbicides continuous exposuredirectly exterminating all plants in a row.
- Herbicides selective exposure, whose action is aimed at the destruction of a certain type of plants.
As a rule, the first group of herbicides is used to destroy plants around production facilities and other places.
First of all, the pesticides are separated according to their chemical structure into organic and non-organic.
Organic pesticides are divided into:
According to the method of influence on a living organism, as well as the mechanism of penetration, they are divided into:
- Contact, which directly affect the contact with the surface of the object.
- Intestinal, have a detrimental effect when ingested with food.
- Systemic, the principle of action of which consists in penetration into the vascular system of the body, which subsequently causes its death.
- Fumigative effects, has a detrimental effect, penetrating the body through the respiratory tract.
Like any chemicals, pesticides have different degrees of danger. The WHO classification of pesticides distinguishes four degrees of danger of their exposure, which can be presented in the form of a table:
Note. Chemical pesticides are major sources of environmental pollution. Their use is mandatory for agriculture, health care and industry.
In order to prevent more harm from pollution, you need to pick them up at the least danger to humanity:
- At the same time, it is necessary to achieve maximum efficiency with little harm, certain requirements have long been established for pesticides.
- To understand how pesticides are involved in improving agriculture and industry, you need to watch the video in this article.
- Many people are interested in what pesticides look like. Usually - this is the liquid, which is treated plants from pests.
It is possible to make a pesticide harmless to health and the environment with your own hands.
- For its preparation it is necessary to take half a cup of hot pepper and the same amount of garlic or onion, cut and mix in a blender.
- The result is a thick mixture.
- To it you need to add 2 cups of warm water and then mix again. The finished solution should stand for a day, preferably in a warm place. After it is necessary to filter and pour into the dispenser.
Here, the pesticide is ready, you can sprinkle the plants! You need to use this solution 4-5 times, after which the pests will disappear.
Instructions for the prevention of harm from exposure to pesticides
You can use only the poison that is allowed for use in a private home.
- Strict observance of the rules of preparation and timing of use.
- Before spraying should learn about the period of protection of the plant, it must be the same.
- The solution should be used immediately. In no case can it be stored. Remember, this is a strong poison!
Council When spraying, you need to take the smallest sprayer, poison is not allowed on the ground, as it can penetrate into it and damage the fruit.
- You can not mix several pesticides, especially incompatible. Sometimes the incompatibility is visible immediately, it may be a precipitate or another reaction. But it happens that you will not notice this with the naked eye, such poison is especially dangerous, as it can cause incredible harm to human health. Sometimes the instructions will indicate which pesticides can be mixed.
- Periodically, the drugs need to be changed, so as not to cause addiction by pests.
- It is necessary to strictly follow the instructions, namely the dosage of pesticide per 10 liters of water.
- Spraying the plants is best in early spring, when the activity of pests is just beginning.
- It is necessary to carry out processing for the time specified in the instruction before harvesting. So that the drug does not affect the person, during this time usually its harmfulness stops.
- Each pesticide has its own consumption rate per square meter. meter, mostly 1-1.5 per 10 square meters. meters
- It is necessary to follow the rules of treatment with pesticides of plants and as much as possible to protect themselves from contact with the skin, eye mucosa and mouth.
If a pesticide comes into contact with a person, remove all clothing and wash thoroughly with soap and water. If the drug gets into the mouth, immediately call a doctor, in no case do not self-medicate, it is very dangerous.
At the end of some tips
Buy pesticides have long been no problem, in any hardware store, on the market you will find the entire range of these drugs:
- As already known, there are a lot of types of pesticides, each has its own characteristics and composition, respectively, and the price will be different.
- For a good harvest invented many different tricks. Various fertilizers, drugs for pest control, all this chemistry, which somehow gets to the person.
- It doesn’t matter whether a person acted with it or not, such means, although slightly, are contained in the harvested crop.
On the other hand, at the present time it is very difficult to harvest a good crop without the use of drugs and chemicals. The main thing is to follow the instructions, it will help to minimize the danger of such agents for humans and plants.
Pesticides are any means intended to protect plants. Pestis in Latin means "contagion", and caedo - "kill." Previously, such funds were called in our country simply pesticides. Today in Russia it is used the name generally accepted in the world "pesticides". Some types of such drugs can be used not only to protect plants, but also animals, and sometimes humans.
The systematic use of such means to protect crops from all kinds of insects, microorganisms, etc., began in the 19th century. In 1939, Dr. P. Muller discovered the special insecticidal properties of dichlorodiphenyltrichloromethylmethane (DDT). This was a real revolution in the protection of plants from insects. Later, other chlorine-containing pesticides, as well as phosphorus-based products, were developed. The third generation of such compounds became synthetic pyrethroids, azoles, etc. And, of course, after the invention of a large number of varieties of such agents, among other things, a classification of pesticides was also developed according to chemical composition and other characteristics.
Chemical composition differences
To protect plants at the moment can be used drugs:
made on the basis of sulfur,
made on the basis of carbamates, etc.
The classification of pesticides by chemical structure is convenient, among other things, in that it makes it easy to select the means of one purpose or another that are most suitable in this particular situation. However, each such drug within the group still has its own characteristic features and may differ from the “related” in strength of the toxic effects on pests or even directionality.
The production of chemically pure preparations for plant protection is very expensive. Therefore, most of the pesticides contain various kinds of additives. When using such plant protection products, one should, among other things, keep in mind that some such impurities may be even more toxic than their active substance itself.
It is necessary to choose such means taking into account possible harm to farm animals, fish in the rivers and lakes or people located near the fields to be treated. The classification of pesticides by toxicity has been developed as follows:
potent poisonous - LD50 up to 50 mg / kg,
highly toxic - LD50 50–200 mg / kg,
medium toxicity - LD50 200–1000 mg / kg,
low toxicity - LD50 is more than 1000 mg / kg.
Also, all these drugs are divided by the degree of resistance to:
very stable with a decomposition period of more than 2 years,
resistant - 0.5-1 year,
moderately stable - 1-6 months.,
unstable - 1 month
Another hygienic feature by which pesticides are classified is the degree of their accumulation in living organisms. In this regard, there are means that can cause:
over cumulation (coefficient less than 1),
pronounced cumulation (from 1 to 3),
Thus, the most dangerous for farm animals will be a potent, poisonous pesticide with over-cumulation, very stable.
Classification by purpose
Crops can be damaged by different types of pests. Special preparations have been developed against each of them. Accordingly, there is a classification of pesticides on the objects of application. There are more than 30 currently prescribed groups of such drugs. But the most popular types of pesticides are still:
scarcity - designed to combat aphids,
acaricides - used from ticks,
bactericides - destroying bacteria,
herbicides - intended for weed control,
zoocides - used to kill harmful animals, such as rats or moles,
insecticides - used to combat harmful insects,
fungicides - used to kill microorganisms, etc.
Classification of pesticides can be made, of course, by the method of use. On the market, these drugs come in different forms. Pests can be destroyed by:
splashing on the soil surface.
Pesticides are often included in the bait. Some types of pesticides can be used in solutions. For example, planting material of crops is often processed this way.
What harm can cause the environment
Chemical composition, methods of use, purpose and mechanism of action are the main features by which classification of pesticides can be made. The use of pesticides is certainly necessary. But nevertheless it is necessary to use such means, of course, as carefully as possible.
Practically all pesticides used today are toxic substances. And of course, they can harm the environment. Such products pollute:
Harmful such drugs can all living organisms. In the first place they suffer from fish in water. According to statistics, from 30 to 70% of all pesticides used in the fields, unfortunately, fall into water bodies. Also, these substances cause great harm to birds and mammals. They cause shifts in hematological parameters in them. In addition, these drugs act on birds as immunosuppressants. In some cases, pesticides can even disrupt the individual or gregarious behavior of birds and mammals.
The classification of pesticides according to the degree of toxicity was considered by us above. Even the most harmless substances in this group contain, even in small quantities, toxic substances. Of course, with the development of science, pesticides are becoming less harmful to people. However, unfortunately, it is still impossible to call absolutely safe means of this variety. In addition, pesticides that have been applied to the fields 20 or more years ago are still preserved in soil and water. Therefore, cases of pesticide poisoning today, unfortunately, are possible.
Toxic chemicals can accumulate:
in plant tissue,
in meat of poultry and agricultural animals.
In this case, they enter the human body not only with food or water, but also simply from the air. Harmful people such substances can cause significant. First of all, they cause disturbances in the work of the nervous system. Also, such compounds are able to destroy the process of metabolism and slow down cellular metabolism. Unfortunately, some of these drugs can also negatively affect the production of hormones in the human body.
It is believed that the most destructive effects of pesticides are experienced by unborn children. Even at low concentrations, such substances freely pass through the placenta.
Pesticides are harmful to humans in this way. However, farmers can not abandon their use. To date, there is no serious alternative to pesticides for the destruction of harmful insects and microorganisms. Without them, the cultivation of various kinds of crops can be extremely inefficient.
The only method on which great hopes are now placed in terms of reducing the harmful effects of pesticides on the human body is ecological farming. When using this technology, the plants themselves can be used to repel pests. For example, adherents of this technique often plant calendula next to bulb onions. This plant scares onion flies. At the same time, it is distinguished by unpretentiousness and does not take too many nutrients from the earth.