What are the hazards of herbicides

According to the statistics of China Pesticide Net, the attention rate of farmers' uncles on "what is the harm of herbicides" has risen sharply. The editor of Pesticide Net also briefly introduced the phytotoxicity of herbicides and the like. Today, what are the harms of herbicides? Rearranged as follows: pesticide manufacturers

What are the hazards of herbicides can be roughly divided into three categories: one is the harm of herbicides to crops; the other is the harm of herbicides to the environment; the third is the harm of herbicides to the human body.

1. Herbicide crop phytotoxicity

Reasons for herbicide phytotoxicity: 1. Pesticide quality problem, 2. Use technical problem. Technical problems in use include: droplets volatilization and drift, soil residues, improper mixing, poor performance of application equipment, irregular operations, etc. Common herbicides are:

1. Imidazolinones: Imidazolium nicotinic acid phytotoxicity conditions: the temperature is lower than 10℃ for 2 days and there is phytotoxicity under the conditions of rainy and little light.

2. Diphenyl ethers: fomesafen (huwei), triflufen (weed burning), oxyfluorfen (gore), etc. This kind of agent is seriously harmful to soybean under high temperature (temperature 28℃) and low humidity (air relative humidity below 65%);

3. Sulfonylureas: Commonly used varieties of this kind of herbicides are: nicosulfuron (Yunongle), chlorsulfuron, metsulfuron-methyl tribensulfuron (superstar), thifensulfuron (baoshou), pyrazosulfuron Sulfuron-methyl, chlorimuron-methyl (sulfuron-methyl), bensulfuron-methyl (Nondex, Vernon), Sunstar (ethoxysulfuron), trisulfuron (Sadosulfuron), sulfone Sulfur-methyl (Baocheng) and so on.

Thifensulfuron-methyl and chlorimuron-methyl are severely harmful to diseases and insects in low temperature, rainy, and severe pests, especially acidic soils with a pH of 6.5 and replanting plots with serious soybean root rot and nematode diseases, which can cause serious pesticide damage and even stop production. Chlorsulfuron-methyl is sensitive to soybeans when it is used during the soybean soil arching period to before a soybean compound leaf is unfolded. The mixed use of chlorimururon-methyl and acetochlor during the soybean soil arching period aggravates the damage. If the temperature is lower than 10℃ for 2 days, the soybean will die; if the soybean is applied after the 2 leaf compound leaf stage, it can cause serious phytotoxicity under low temperature conditions.

4. Amides: Metolachlor (Dur), High-efficiency Metolachlor (Gyndur), Acetochlor (Henas), Preliminary (Rifeite), Butachlor (Ma Shelter), Mefenacet, Propolachlor (Pulebao), Dibaran etc. The acetochlor used in soybean fields is seriously harmful to soybeans under the conditions of low temperature and high humidity, which can reduce the yield by 20-30%. 90% is safer to soybeans than 50% acetochlor. Too high dosage of acetochlor in maize fields, low temperature after application, and too deep seeding are likely to cause phytotoxicity. The safety of soybeans and corn in descending order is metolachlor-propisochlor-acetochlor. Paddy field: Mefenacet is better for rice than butachlor; butachlor is more harmful to rice seedbeds in the north, and transplanted fields: unrelief, weak seedlings, uneven ground, deep water flooding the rice core Severe phytotoxicity under low temperature and other conditions. Excessive use of synergists in seedbeds and Honda will aggravate butachlor harm.

5. Triazinones: The cause of the triazone phytotoxicity is: ①Too much dosage in soybean field. ② After sowing soybeans, apply pesticides before seedlings. ③ Poor drainage of low-lying land, water accumulation in the field, high humidity and low temperature, pests and diseases cause poor growth and development of soybeans. ④Sandy soil and loamy soil with soil organic matter less than 2%. ⑤Individual sensitive varieties, etc. ⑥Improper mixed use of mesotrione can aggravate soybean phytotoxicity, which can cause soybean death. Corn field ①Soil with organic matter less than 2%, after sowing, pre-emergence pesticide application is easy to produce phytotoxicity; ②After corn sowing, pre-emergence application after heavy rain ③Maize single-cross planting field, male parent phytotoxicity in inbred lines Heavier than the mother, often causing death of the father.

6. Quinoline carboxylic acids:

Quinclorac is a hormonal herbicide: Cause of phytotoxicity: ① Overuse. ②Rice seedbed: rice is used at the 2~2.5 leaf stage, the symptoms of phytotoxicity are not obvious, and it only appears after tillering. ③Uneven spraying on the seedbed and Honda can easily cause phytotoxicity, and it can cause serious damage locally. The use of Quinclorac in the seedbed is more harmful than Honda and reduces production.

7. Oxadiazolones; 8. Cyclohexenones; 9. Triazines; 10. Phenoxycarboxylic acids; 11. Carbamates and thiocarbamates; 12. Dinitro Anilines: trifluralin, pendimethalin (pendimethalin, Shitianbu), etc. 13. Organophosphates; 14. Aryloxyphenoxypropionates; 15. Pyrimidine oxygen (sulfur) benzoates; 16. Other heterocyclics; 17. Plant growth regulators, etc.

2. The harm of herbicides to the environment

The phytotoxicity of herbicide residues has become the most serious problem, making the determination of herbicide residues in water and soil a prerequisite for the application of this herbicide. Affected by factors such as soil pH and temperature, the residues will cause phytotoxicity to sensitive crops after cropping rotation, even after 2-3 years of application. Bensulfuron-methyl is a systemic and conductive sulfonylurea herbicide used on a large scale worldwide. It is very easy to bring potential harm to the ecological environment, food crop yield, food safety and human living environment [5- 6]. Some herbicides have caused phytotoxicity in the large-scale promotion, especially the hidden phytotoxicity has a great impact on the yield, resulting in the adverse consequences of weeding not increasing or reducing weeding. Due to changes in cultivation and farming systems, widespread application of herbicides, mixed herbicides, genetically modified crops, etc., weed communities have changed and weed resistance has increased, resulting in a significant decline in the efficacy of commonly used herbicides. Different crops have different requirements for herbicides. Big. How to solve the problem of poisoning the following crops has become an urgent problem in the application of herbicides.

3. The harm of herbicides to the human body

Herbicides have different effects on the human body. Some are low-toxic, some are moderately toxic. The impact on humans is basically not large. Eating should not affect the human body, or it is very small. Because the principles of herbicides and pesticides are different, they are basically through the impact The formation of protein or nucleic acid of crops, so as to achieve the purpose of weeding, so the impact on people is basically a lack of nutrition.

When people consume the food produced by spraying "herbicide", they must also accumulate "herbicide" ingredients in the human body. No matter which organ of the human body the ingredients are accumulated, it will affect its organ function; Once the impact exceeds the limit, lesions will occur immediately. Human body immunity is different; that is to say, it is unlikely that all people who have consumed food that has been weeded with medicines will get sick, but I can conclude that the "herbicide" ingredients accumulated in the human body will definitely affect human health. In recent years, the increase in human hair loss, various types of leukemia, various tumors, renal necrosis, femoral head necrosis, etc., is mostly related to "herbicide"; especially the increase in leukemia and tumors in children and young children , It can be concluded that there is a direct relationship with "herbicide". I dare not think, how can people survive in the long run? For the survival of mankind, for the beauty of the natural environment, and for the co-existence of all things, experts call on relevant departments to pay attention to "herbicide", and should be able to take measures as soon as possible to stop production and use as soon as possible, which is harmful to health and destroys nature Herbicide for the environment.