Herbicides - Type

According to the transmission of herbicides within the plant body, they can be divided into three types: contact herbicides, internal absorption conductive herbicides, and contact and internal absorption conductive comprehensive herbicides.

1. Contact herbicide

(1) Including herbicides such as herbicides and glyphosate.

(2) This type of drug only kills the aboveground part of weeds (i.e. the part that comes into contact with the drug), has a local killing effect, and has no transmission effect. Its control effect on the underground part of weeds (or perennial deep rooted weeds with underground stems) is poor.

2. Internally aspirated conductive herbicides

(1) Including drugs such as glyphosate and glyphosate.

(2) This type of drug can be transmitted to the plant body through the parts in contact with weeds (such as leaves, shoot sheaths, stems, and roots), which can cause the entire plant to die.

3. A comprehensive herbicide with contact killing and internal absorption conduction

Including drugs such as chlorpyrifos, these drugs have dual functions of contact killing and internal absorption conduction.

Herbicides - Mode of Action

According to the properties of herbicides, they can be divided into selective herbicides and fungicides.

1. Selective herbicides

(1) Including drugs such as Guo'er, Gaicao Neng, Fluralin, Pucao Jing, Ximajin, etc.

(2) The characteristic of this type of drug is that it only kills weeds and is harmless to seedlings.

2. Killing herbicides

(1) Including drugs such as glyphosate.

(2) This type of drug is toxic to all plants. As long as it comes into contact with the green part of the plant, both seedlings and weeds will be harmed or killed.

Herbicides - Application time

It can generally be divided into pre sowing treatment agents, post sowing pre seedling treatment agents, and post seedling treatment agents.

1. Pre broadcast treatment agent

It refers to the sealing treatment of the soil before planting crops, such as the use of fluralin in cotton fields or the use of glyphosate in wheat fields. Both involve spraying herbicides into the soil and mixing them into the soil at a certain depth before planting cotton or wheat, so that they can be absorbed by the young roots and buds of weeds, thereby preventing or reducing the volatilization and photodegradation losses of herbicides.

2. Post sowing seedling pre-treatment agent

(1) It refers to soil treatment, including drugs such as glyphosate and atrazine, after crop sowing but before emergence.

(2) When using this method, the weed sheath and young leaves are mainly selected to absorb herbicides that are transmitted to the growth point, which is safer for crop sprouts.

3. Post seedling treatment agent

(1) It refers to the direct spraying of herbicides on weed plants after the emergence of weeds, including drugs such as bentazone, imidacloprid, and dichloromethane.

(2) Post seedling herbicides can usually be absorbed by the stems and leaves of plants and can be transmitted to other parts of the plant.

Herbicides - Mechanism of Action

It can generally be divided into growth regulators (such as 2,4-D), photosynthesis inhibitors (such as glyphosate), amino acid biosynthesis inhibitors (such as glyphosate), fatty acid biosynthesis inhibitors (such as glyphosate), and cell division inhibitors (such as fluralin).