Herbicidal pesticides

Which herbicide is the most powerful?

Systemic conductive herbicides are absorbed by the roots or leaves, bud sheaths or stems, and are then transmitted into the plant, causing the plant to die. .

1. Classification based on mode of action

(1) Selective herbicides: Herbicides have different degrees of resistance to different types of seedlings. This agent can kill weeds. And harmless to seedlings. Such as Gaicaoneng, trifluralin, prometryn, simazine, Goer, etc.

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

2. Classification based on the movement of herbicides within the plant

(1) Contact herbicides: When the herbicide comes into contact with weeds, it only kills the part in contact with the herbicide. It has a local killing effect and cannot be transmitted in plants. It can only kill the above-ground parts of weeds, but is less effective on the underground parts of weeds or perennial deep-rooted weeds with underground stems. Such as herbicides, paraquat, etc.

(2) Systemic conductive herbicides: After the herbicide is absorbed by the roots or leaves, coleoptiles or stems, it is transmitted into the plant, causing the plant to die. Such as glyphosate, prometryn, etc.

(3) Systemic conduction and contact-killing comprehensive herbicides: It has the dual functions of systemic conduction and contact-killing, such as chlorfenac, etc.

Help: What are the herbicides? In addition to glyphosate, what other paraquat are there

1. Biocidal herbicides: toxic to all plants, such as glyphosate, paraquat (gramoxone), etc., which can be used before transplanting farmland.

2. Contact herbicides: They can only kill the parts of plants that are in direct contact with the pesticide. Such as enemy barnyard grass and evil grass spirit.

3. Systemic conductive herbicides: roots, stems, leaves, buds, sheaths →absorption →transmission tissue →whole plant →destroy physiological balance →death. Such as 2,4-D butyl ester, prometryn, etc.

3. Selective herbicides: selectively kill → non-toxic/very low toxicity to other plants. Such as fentanyl, bentazon, etc.

Herbicide has special effects on cowgrass and barnyard grass in rice fields, and can effectively control duckweed, melongrass, sedge, crabgrass, upland barnyard grass, cricket grass, wheatgrass, wild oats, etc. It is an annual weed that is safe for crops such as rice, wheat, rapeseed, peanuts, soybeans, cotton, corn, and sugar cane.

What pesticides are specifically designed to kill weeds?

Herbicides refer to chemicals that can completely or selectively kill weeds. They are also called herbicides. They are a class of substances used to destroy or inhibit plant growth.

Among them, sodium chlorate, borax, arsenate, and trichloroacetic acid have the effect of killing any kind of plants. Their effects are affected by three factors: herbicides, plants, and environmental conditions.

Commonly used varieties of herbicides are organic compounds, which can be widely used to control weeds, miscellaneous irrigation, Miscellaneous trees and other harmful plants.

Herbicides can be classified according to mode of action, application site, source of compounds, etc.

Classified according to mode of action

(1) Selective herbicides: Herbicides have different degrees of resistance to different types of seedlings. This agent can kill weeds, while Seedlings are harmless. Such as Gaicaoneng, trifluralin, prometryn, simazine, Goer herbicides, etc.

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

Classification based on the movement of herbicides within the plant

(1) Contact herbicides: When the herbicide comes into contact with weeds, it only kills the parts that are in contact with the herbicide. The local killing effect cannot be transmitted in the plant body. It can only kill the above-ground parts of weeds, but is less effective on the underground parts of weeds or perennial deep-rooted weeds with underground stems.

Such as herbicides, paraquat, etc.

(2) Systemic conductive herbicides: After the herbicide is absorbed by the roots or leaves, coleoptiles or stems, it is transmitted into the plant, causing the plant to die. Such as glyphosate, prometryn, etc.

(3) Systemic conduction and contact-killing comprehensive herbicides: It has the dual functions of systemic conduction and contact-killing, such as chlorfenac, etc.

Classification based on chemical structure

(1) Inorganic compound herbicides: Compounds composed of natural mineral raw materials 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, triazepines--prometryn, substituted ureas--herbicide No. 1, phenoxyacetic acids--2-methyl-4-chloride, pyridines--clothone, dinitrate Anilines - trifluralin, amides - lasso, organophosphorus - glyphosate, phenols - sodium pentachlorophenate, etc.

Classification by usage method

(1) Stem and leaf treatment agent: Mix the herbicide solution with water and spray it evenly on the plants with fine mist droplets. This spraying method is used Herbicides are called stem and leaf treatment agents, such as glyphosate, glyphosate, etc.

(2) Soil treatment agent: Spray the herbicide evenly onto the soil to form a chemical layer of a certain thickness. When the buds, seedlings and roots of the weed seeds are contacted and absorbed, the herbicide will be killed. Herbicides with this effect are called soil treatment agents, such as simazine, prometryn, trifluralin, etc., which can be applied by spraying, watering, or poisoning soil methods.

(3) Stem, leaf, and soil treatment agents: It can be used for stem and leaf treatment, as well as soil treatment, such as atrazine, etc.

What herbicide is used for trigonella

Dastardaga herbicide

1. Why are the effects of glyphosate herbicides different when applied?

Glyphosate is an organophosphate systemic herbicide, also known as Roundup and Zhencaonin. It has a broad spectrum of herbicides, strong biocidal properties, and leaves no residue in the soil. It is widely used in chemical weeding in no-till fields and directional weeding in forests and orchards. It can kill various weeds growing on the ground, but it can also kill weeds that have sprouted underground and have not yet been unearthed. Grass is ineffective. Glyphosate herbicide is effective against more than 40 families of weeds, including monocotyledonous, dicotyledonous, annual and perennial herbaceous weeds, shrubs, algae, ferns, etc. According to our investigation and observation, the inconsistent weeding effect of glyphosate herbicide reported by farmer friends is due to the following reasons:

First, the efficacy of the herbicide will vary according to different farming methods. Using glyphosate herbicide is best for no-till seeding. Spray the crop 1-3 days before sowing, or sow after spraying to seize the season. Pre-sowing medicines do not come into direct contact with crop seeds and will not affect crop seed germination and seedling growth. Therefore, the weeding and weed suppression effects are better than plowing. No-tillage does not move weed seeds from the inner layer of the soil to the topsoil, so weed seeds are difficult to germinate. Once the crops grow and are closed, weed seeds and seedlings cannot germinate and grow because they cannot see sunlight. Therefore, the weeding effect of glyphosate herbicide on no-till land will be better than that on tilled land.

Second, when weeds are used in different growth stages, their efficacy will be different. Glyphosate is a systemic herbicide, so it should be applied when weeds are growing most vigorously. In terms of time, it is generally between March and October. In terms of botanical characteristics, the best time to apply medicine is before flowering. Generally speaking, annual weeds are about 15 cm in height, perennial weeds are about 30 cm in height and have 6-8 leaves. It is the most suitable. Ignoring the growth period of weeds and blindly spraying pesticides to eliminate weeds after they have aged will, of course, not achieve the desired control effect. Weeding between crop rows is more effective and safe when there is a certain gap between the crop plants and the weeds. At this time, when glyphosate herbicide is used, the crops have low sensitivity to the drug and poor conductivity because the lower leaves have aged, so the drug has little impact on the crops. For example, this method can be used for weeding between corn rows, and weeding between rows of beans and melons after they are put on the shelves.

Third, the efficacy will be different depending on the spraying concentration. According to the survey, farmers do not have strict requirements on the concentration of glyphosate when using glyphosate like other pesticides. They are more arbitrary and increase or reduce the dosage.

Be sure to consider the type of weed when determining the concentration to use. Generally, grass weeds are sensitive to glyphosate and can be killed by low-dose liquid. However, when controlling broadleaf weeds, the concentration must be increased; some perennial rhizome-propagating malignant weeds require higher concentrations. , weeds have older leaves and higher drug resistance, so the corresponding dosage should also be increased. For example, when controlling weeds in orchards, 10 grams of glyphosate can be mixed with 500-700 grams of glyphosate and 30-40 kilograms of water when controlling annual grass weeds; when controlling annual broadleaf weeds, the dosage should be increased to 750-1000 grams; when controlling perennial malignant weeds, the dosage should be increased to 750-1000 grams; When weeding, the dosage should reach 1250-1500 grams. However, overdosing will quickly kill the conductive tissue of the plant, which is not conducive to the absorption of the medicinal solution and reduces the efficacy. Therefore, in order to economical use of the medicinal solution, the young grass should be killed with a lower concentration first, and then the corresponding concentration should be used after about 10 days. Directional spray? Vicious weeds.

Glyphosate is not a herbicide that can kill wild garlic

What you are talking about is the lily weed small root garlic, also known as sage. I don’t know what crop you want to use. To control small-root garlic in the field, if there are small-root garlic in broad-leaf crop fields (such as rape fields), there is currently no herbicide that can kill small-root garlic and is safe for the crop. It is recommended that you use manual methods to pull it out. If it is a grass crop field (such as winter wheat), you can try the phenoxycarboxylic acid herbicide mentioned on the first floor. It should have good results. The dimethyltetrachloride mentioned on the first floor is this type of agent. There are studies It shows that the effect of using (dimethyltetrachlorogibberellin) to control small root garlic in wheat fields is more than 96%. If it is non-cultivated land, methylsulfuron-methyl can be used, but it should be noted that the residual effect of methylsulfuron-methyl is long, 2-3 years after application. Some crops cannot emerge normally. In addition, if glyphosate does not work as you said, it may be because the dosage is not enough. If the dosage is increased to an amount that can control perennial weeds and reeds, it should also be able to control small-rooted garlic. Good results...