Pesticides refer to chemical synthetic substances or substances derived from biological or other natural products and produced through applied biotechnology, or mixtures of several such substances and their formulations, used to prevent, eliminate, or control diseases, insects, weeds and other harmful organisms that harm agriculture and forestry, as well as to purposefully regulate, control, and influence the metabolism, growth, development, and reproduction processes of plants and harmful organisms.

Today, as people's demands for environmental quality continue to rise, the requirements for pesticides are becoming increasingly strict, and at the same time, this has also promoted the rapid development of pesticides. Under the premise of safeguarding human health and ecological balance, beneficial organisms should be effectively protected and harmful organisms should be better controlled, so as to promote the sustainable development of modern agriculture. The substances with special functions used in this process are collectively referred to as "pesticides."

I. Classification Based on Raw Materials

① Inorganic PesticidesThese are mainly pesticides processed and formulated from natural minerals. Common ones include lime, sulfur, aluminum phosphide, copper sulfate, etc.

② Organic PesticidesThese are mainly pesticides composed of carbon and hydrogen elements. They can also be classified according to their source and properties into botanical pesticides (pyrethrum, azadirachtin, etc.), mineral oil pesticides (petroleum emulsion, etc.), microbial pesticides (Bacillus thuringiensis, agricultural antibiotics, etc.), and artificially synthesized organic pesticides.

II. Classification Based on Use

① Insecticides ② Acaricides ③ Fungicides ④ Nematicides ⑤ Herbicides ⑥ Rodenticides ⑦ Plant Growth Regulators

III. Classification Based on Mode of Action

(1) Insecticides

① Stomach poisons ② Contact poisons ③ Fumigants ④ Systemic agents ⑤ Antifeedants ⑥ Repellents ⑦ Attractants

(2) Fungicides

① Protective fungicides ② Curative fungicides ③ Eradicant fungicides

(3) Herbicides

① Translocated herbicides ② Contact herbicides ③ Selective herbicides ④ Non-selective herbicides

The following principles must be followed when using pesticides, and they must not be used blindly.① Select appropriate pesticides according to the target pest ② Determine the appropriate timing of application according to the occurrence of the target pest ③ Master the appropriate concentration and apply at the right time and in the right amount ④ Choose the appropriate application method according to the characteristics of the selected product.

Pesticides should not be used under weather conditions such as strong winds, rain, or high temperature and high humidity, otherwise it will reduce efficacy, increase environmental pollution, and increase the chance of phytotoxicity. If pesticides are used during the rainy season, systemic and fast-acting pesticides should be chosen, or the application method should be changed (from spraying to root drenching).

Organophosphorus pesticides have a relatively short residual efficacy period (7-10 days), require larger application amounts, and easily cause the target pest to develop resistance.

The main advantage of pyrethroid pesticides is that they require small application amounts, and the main disadvantage is that they easily lead to resistance.

Pyrethroid insecticides are characterized by high efficiency, broad spectrum, low toxicity, and low residue; the disadvantage is that most of them have no systemic or fumigant action and easily lead to resistance.

Nereistoxin derivatives (bisultap, monosultap) belong to nerve poisons; broad spectrum; have contact, stomach poison, and fumigant action; low toxicity and low residue;

Abamectin insecticides have the characteristics of high efficiency, broad spectrum, long residual efficacy period, safety to natural enemies, difficulty for pests to develop resistance, easy degradation, no residue, and no phytotoxicity to crops.

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