What are the four methods for rapid identification of herbicide toxicity?

Here's a quick way to identify herbicides.

of the four methods.

Highly toxic herbicides can easily cause pesticide damage problems, so they are not recommended, but what if you decide for yourself the toxicity of buying herbicides? There are generally four ways to determine the toxicity of herbicides, so let's take a look at them together.

In order to simulate the actual control of the spray method in the forest, in order to reduce the test error, try to make each insect receive the same amount of medicine, the spraying appliance is required to have a certain pressure, so that the size of the fog point is consistent and the spray is uniform.

The test insects were impregnated with different concentrations of diluted solution, taken out immediately, placed on absorbent paper to suck out the excess solution, moved into the container of each container group, used fresh leaves as feed, and then covered with gauze or gauze, kept indoors, recorded room temperature, and observed the poisoning and death at different times.

Spray the pesticide on a certain area of the surface to form a uniform film (usually a petri dish lined with filter paper, or take out the needles after soaking them in the solution), and then let the pests on it, let them contact with the film for a certain period of time, and then move back to the normal container to feed, or observe the poisoning and death during the contact with the film.

A quantitative amount of liquid was dropped into the back of the chest of the test insects, and the poisoning and death were observed regularly. The advantage of this method is that the acceptable dose per gram of worm body (micrograms is usually used.

to indicate that the dosage is easy to control and the test error is small; The disadvantage is that it is time-consuming, and the solvent being processed, the position of the dripper, the size of the dripper, etc., will affect the toxicity. These factors should be taken into account when applying this method and be as consistent as possible to obtain accurate results.

Insecticides are toxic chemicals, and different insecticides have different toxicity, drug strength and residual effect due to different molecular structures. The toxicity grade of an insecticide product is based on the actual toxicity of the product rather than the toxicity grade of the original drug, and in addition to relying on the toxicity of the insecticide itself, it is also related to its dosage form, usage, etc.

For example, carbofuran.

It is a highly toxic pesticide, but the use of 3% carbofuran granules is only poisoning, which greatly reduces its harm. In addition, avermectin.

It is also a highly toxic pesticide, but due to the low content of the preparation it is processed, the oral and transdermal toxicity of its preparation is in the category of low toxicity. Any herbicide is toxic, so even if it is a low-toxicity herbicide, excessive use will cause pesticide problems, please pay attention to the majority of farmers.

Insects can be sprayed with different concentrations of solutions, so that the condition of insects can be observed, the effect of pesticides can be tested by using spray methods, and the pests can also be observed by spraying pesticides to form a film so that pests can live on the surface, and drip methods can also be used.

The four methods are: 1 to check the density of the spray, 2 to observe the color on the test paper, 3 to spray on the plastic wrap to observe the adhesion, 4 drip method, the drug is dropped on the body of the insect to observe the poisoning death.

At this time, it can be judged according to the efficacy of the herbicide, the ratio of the herbicide, the production date, the production batch number, and the ingredients.

These four methods are identified by pharmacological testing, identified by color, identified by taste, and identified by the concentration of liquid.

Herbicides have not been used in our country for a long time. In my impression, it was only in the eighties of the last century that it began to be popularized and used. Herbicides are divided into two categories: biocidal herbicides and selective herbicides.

Due to the ignorance or carelessness of the herbicide habits in the application of farmers, some herbicide pesticide damage occurred in the actual application, resulting in damage to crops and even death.

So, how do you prevent herbicides from causing pesticide damage to crops?

First of all, the soil structure is damaged, and herbicides with high residues in the water soil are not used. For example: herbicidal king, chlorsulfuron, amibesulfuron, mesulfuron-methyl and other ......These herbicides have been (or are progressively) banned.

They remain in the soil for a long time (some years, even more than ten years), and after a few years, they are ...... to crops such as watermelon and sugar beetThe cultivation of pesticides is harmful. If farmers have used a large number of the above pesticides before, it is recommended to plant gramineous crops instead of single-season dicot cash crops. In order to avoid drug damage and unnecessary economic losses.

Secondly, do not use herbicides indiscriminately. In view of the characteristics of selective herbicides, it is important not to confuse the selected objects in use. If the herbicide is used incorrectly, it will be harmful to the pesticide at least and the harvest will be wiped out at worst.

Therefore, the herbicides purchased should be classified and marked prominently, and carefully checked and checked before use.

Third, do not abuse herbicides. In the use of selective herbicides, the drug should be used according to the requirements of the instructions: it should not be used before the safe period of crop growth that is required to be reached, nor should the dose be increased arbitrarily in order to kill the herbs quickly.

These are prone to pesticide damage and delay the growth and development of crops. The application of some compound biocidal herbicides is also prone to pesticide damage if used improperly. (For details, you can refer to the "How Many Days Can You Grow Crops After Using Methyl Glyphosate").

Fourth, develop good medication habits. Before each use of herbicide, the spraying equipment should be cleaned and sprayed with water; After applying the drug, wash it again with water and test spray. In order to avoid the residue of herbicide to cause pesticide damage to crops.

When using herbicides, try to choose sunny and windless weather. When spraying herbicides, use herbicide protective cover to avoid herbicide drift and other crops from causing pesticide damage.

1.Through manual prevention and control, 2Drug prevention and control, 3Biological control, 4Animal prevention and control, 5It can also be solved through medical prevention and control.

Look at the kind. Watch the news today. 100 acres of saplings were planted in the fields where herbicides had been used, and none of them were alive.

Herbicides can be classified according to the mode of action, application site, compound** and other aspects.

Classified according to mode of action.

1) Selective herbicides: herbicides have different degrees of resistance to different kinds of seedlings, and this agent can kill weeds and be harmless to seedlings. Such as Gaicaoneng, Fluorin, Prometrinet, Simazine, Guoer herbicide, etc.

2) Herbicides: Herbicides are toxic to all plants, as long as they come into contact with the green part, regardless of seedlings and weeds, they will be damaged or killed. It is mainly used before sowing, before sowing and before emergence, and on the main and secondary roads of the nursery. Such as glyphosate, etc.

Herbicides are classified according to their movement through the plant.

1) Contact herbicide: When the agent is in contact with weeds, it only kills the part that is in contact with the agent, which plays a local killing role and cannot be conducted in the plant. It can only kill the aboveground part of the weed, and the effect is less effective on the underground part of the weed or perennial deep-rooted weed with underground stems.

Such as herbicidal ether, paraquat, etc.

2) Systemic conductive herbicide: After the agent is absorbed by the root system or leaves, bud sheath or stem, it is conducted into the plant and dies. Such as glyphosate, prometrinet, etc.

3) Systemic conduction and contact killing comprehensive herbicide: It has the dual functions of systemic conduction and contact killing, such as chloricidal and so on.

Classified according to chemical structure.

1) Inorganic compound herbicides: composed of natural mineral raw materials and compounds that do not contain carbon, such as potassium chlorate, copper sulfate, etc.

2) Organic compound herbicides: mainly synthesized from organic compounds such as benzene, alcohols, fatty acids, and organic amines. Such as ethers - gol, triazine benzene - prometriazine, substituted urea - herbicide No. 1, phenoxyacetic acid - 2 methyl 4 chloro, pyridine - capitonol, dinitroaniline - fluorin, amides - Lasso, organophosphates - glyphosate, phenols - sodium pentachlorophenol, etc.

Categorized by method of use.

1) Stem and leaf treatment agent: the herbicide solution is mixed with water, and the herbicide is evenly sprayed on the plant with fine droplets, and the herbicide used in this spraying method is called stem and leaf treatment agent, such as cover grass energy, glyphosate, etc.

2) Soil treatment agent: the herbicide is evenly sprayed on the soil in a certain thickness of the drug layer, when the young shoots, seedlings and roots of weed seeds are absorbed by contact and play a role in killing herbicides, this effect of herbicides, called soil treatment agents, such as simazine, prometrinet, fluoralin, etc., can be applied by spraying method, watering method, and poisonous soil method.

3) Stems and leaves, soil treatment agent: can be used as stem and leaf treatment, can also be used as soil treatment, such as atrazine, etc.

Because herbicides contain a variety of toxic substances, once they come into contact with the human body, or even after ingestion, they can lead to herbicide poisoning, causing harm to the **, digestive, respiratory and other systems, and may even lead to death in severe cases. After herbicide poisoning, there is generally no specific drug for **, if poisoning is found, it is recommended to go to the emergency department of the hospital to reduce the absorption of poison and accelerate its excretion.

It is low toxicity to crops and animal experiments, but highly toxic to humans, no specific drug, please treat the symptoms**, and the mortality rate is high.

1. Single dose types of corn herbicides.

1.Amide herbicides: This kind of product is currently the most important type of herbicide in corn field, which can be absorbed by weed sprouts, and the soil is closed before the weeds germinate, which can effectively control annual grass weeds and some annual broad-leaved weeds.

There are many varieties of this type of herbicide, such as acetochlor, alachlor, butachlor, metolachlor, protochlor, etc.

2.Triazine herbicides: can effectively control annual broad-leaved weeds and annual gramineous weeds, mainly absorbed by weed roots, and can also be absorbed by weed stems and leaves in small amounts.

The representative varieties include atrazine, cyanoazine, simazine, promerazine, etc., among which atrazine is used more, which is safer for maize and has the highest activity. However, atrazine should be mixed with acetochlor to reduce the dosage, improve the weeding effect and the safety of subsequent crops.

3.Phenoxycarboxylic acid herbicides: mainly used for the control of broad-leaved weeds and fragrant aconite after corn seedlings. Representative varieties include 2methyl4 sodium chloride salt and butyl ester. Among them, 2methyl4 chloride sodium salt is widely used in corn fields to control aconite, but it is easy to produce pesticide damage when it is used improperly.

4.Sulfonylurea herbicides: nicosulfuron, sulfonesulfuron can be used to control gramineous weeds, sedge weeds and some broad-leaved weeds in corn fields; Thiocillon can be used in corn fields to control annual broadleaf weeds.

5.Other herbicides: paraquat and glyphosate are biocidal herbicides that can be sprayed after maize is 40 cm tall and can be used to control a wide range of weeds; It can also be used to control broad-leaved weeds in corn fields with varieties such as Taron, Paraquilla, bromobenzonitrile, and Bendapine.

Second, the types of corn herbicides.

Corn herbicide is a general term for herbicides used in corn fields.

It is more poisonous than rat poison, and it is drunk through the intestines.

Judging the quality of a herbicide depends on the effect of weeding, whether the residual drug is harmful to crops and other hail oaks. Herbicides can be widely used to control weeds, shrubs, trees and other harmful plants in farmland, orchards, flower nurseries, grasslands and non-cultivated land, railways, rivers, reservoirs, warehouses and other places. <>

Herbicides are applied by stem and leaf treatment, soil treatment and weeding with herbicide. The most commonly used methods are stem and leaf treatment during the growth period and soil treatment before seedlings after sowing. Before using the herbicide, the plot should be kept moist, and the water consumption should be increased when the plot is dry, so as to facilitate the emergence of weeds and timely killing.

Herbicides are accepted by farmers because they are fast, efficient, and easy to operate. However, the use of chemical herbicides is highly technical. In the process of chemical weeding, improper selection of chemical herbicides and improper application methods will lead to poor control effects and even pesticide damage.

It is hoped that the majority of farmers will correctly choose herbicide varieties, adopt scientific and technical methods, and master application skills. When using herbicides, be sure to apply them strictly in accordance with the instructions for use. <

Choose the right herbicide according to the crop and weeds. Herbicides are generally selective, and different herbicides have different effects on crops and weeds. Farmers must carefully read the product label or instructions when choosing herbicides, or purchase them under the guidance of agricultural technicians.

The herbicide chosen should be safe for the crops used and effective against weeds in the crop field. Choose the right herbicide according to the crops and weeds in different growing seasons. The herbicide application period can be divided into pre-sowing soil treatment, post-sowing pre-seedling soil treatment and post-seedling stem and leaf treatment.

The appropriate herbicide should be selected according to the application period. When chemical weeding is carried out, it is necessary to clarify the situation of farmland seedlings and grasses, and select pesticides according to the types and distribution of weeds.

With the right herbicide varieties, it can be said that the control effect is 50%. However, if the application is unreasonable, it is difficult to achieve the ideal control effect, and may even cause chemical weeding and other pesticide damage after the three-leaf stage of corn. The nozzle of the nebulizer should be lower than the height of the flare to prevent the liquid from being sprayed onto the flare.

Inside the heart of the leaf. <>

You can resist the effect of herbicides, you can also look at the herbicide's wax leakage accompanying ingredients, you can also look at the herbicide's expiration date, you can also search for the herbicide's **, you can also look at the toxicity of the herbicide.