What are the classifications and functions of agrochemical?

Insecticides

– Function: Used to control pests in agriculture, forestry, animal husbandry, and public health. They can cause pests to die from poisoning through methods such as stomach toxicity, contact toxicity, fumigation, and systemic action, thereby protecting crops, trees, and humans from pest damage.

– Examples: Chlorpyrifos, an organophosphorus insecticide, can inhibit the activity of acetylcholinesterase in pests, leading to nervous disorders and death in pests. Cypermethrin, a pyrethroid insecticide, can act on the nervous system of pests, making them over-excited and die.

Fungicides

– Function: Used to control plant diseases. They can inhibit or kill plant pathogenic bacteria, prevent the infection and spread of bacteria, protect plants from disease hazards, ensure the normal growth and development of plants, and improve crop yield and quality.

– Examples: Tebuconazole, a triazole fungicide, can inhibit the biosynthesis of ergosterol in bacteria, destroying the cell membrane function of bacteria. Azoxystrobin, a strobilurin fungicide, can inhibit the respiratory function of bacteria cells, thus playing a bactericidal role.

Herbicides

– Function: Used to control weeds in farmland, orchards, tea gardens, lawns, and other places. By inhibiting the growth of weeds and interfering with their physiological metabolism, they can cause weeds to die or their growth to be inhibited, reducing the competition for nutrients, water, and sunlight between weeds and crops, and improving crop yield and quality.

– Examples: Acetochlor, an amide herbicide, mainly controls weeds by inhibiting the growth of young shoots and roots of weeds. Nicosulfuron, a sulfonylurea herbicide, can inhibit the activity of acetolactate synthase in weeds, preventing the synthesis of amino acids in weeds, and thus causing weeds to die.

Miticides

– Function: Specifically used to control mite pests that harm crops. They can kill eggs, larvae, nymphs, and adults of mites, effectively controlling the population of mite pests and preventing them from causing damage to crops.

– Examples: Pyridaben can interfere with the nervous system of mites, paralyzing and killing them. Etoxazole mainly acts on the eggs and larvae of mites, inhibiting the hatching of mite eggs and the growth and development of larvae.

Plant Growth Regulators

– Function: Used to regulate the growth and development process of plants, including promoting or inhibiting plant growth, flowering, fruiting, and ripening. They can also improve the stress resistance of plants, enabling plants to better adapt to environmental changes, and achieving the goals of increasing crop yield and improving quality.

– Examples: Indole-3-acetic acid, an auxin, can promote the elongation and division of plant cells. 6-Benzylaminopurine, a cytokinin, can promote cell division and expansion and delay plant senescence.

Rodenticides

– Function: Used to control the damage of rodents to crops, food, buildings, etc. Through methods such as stomach toxicity and fumigation, they can cause rodents to die from poisoning, reducing the damage of rodents to agricultural production and human life.

– Examples: Bromadiolone, an anticoagulant rodenticide, can inhibit the function of vitamin K in rodents after ingestion, leading to coagulation disorders and bleeding to death. Aluminum phosphide, a fumigant rodenticide, decomposes to produce phosphine gas in rodent holes, poisoning and killing rodents.

Nematicides

– Function: Specifically used to control plant-parasitic nematodes. Through contact toxicity, systemic action, and other methods, they can inhibit or kill nematodes, reducing the damage of nematodes to plant roots and other parts, and ensuring the healthy growth of plants.

– Examples: Abamectin is a sixteen-membered macrolide compound with insecticidal, miticidal, and nematicidal activities. It has a good control effect on many nematodes such as root-knot nematodes. It can interfere with the neurophysiological activities of nematodes, paralyzing and killing them. Fosthiazate can inhibit the synthesis of acetylcholinesterase in nematodes. It has systemic properties and can effectively control nematode diseases of various crops. It has a relatively long residual period in the soil.

Molluscicides

– Function: Used to control mollusks such as snails and slugs. Through stomach toxicity, contact toxicity, and other effects, they can cause mollusks to be poisoned, dehydrated, or stop eating, thereby achieving the goal of controlling their population and reducing the damage to crops.

– Examples: Metaldehyde is a highly selective molluscicide. When snails, slugs, and other mollusks come into contact with or ingest it, they will be poisoned, secrete a large amount of mucus, and finally die due to dehydration. Carbaryl has stomach and contact toxicity to mollusks. It can interfere with their nervous systems, causing disorders in their physiological functions and death.