In recent months, a number of international agencies have predicted the possibility of extreme and destructive weather around the world. A report released by the World Meteorological Organization in May predicted that there is a 98 percent chance that at least one of the next five years will be the warmest on record. The current warmest year on record was 2015-2016, when the world experienced a 21-month-long El Nino.
On June 8, the National Oceanic and Atmospheric Administration issued an El Nino alert, declaring that the climate phenomenon had already occurred. By winter, there is an 84 percent chance that El Nino will be "moderate to strong."
In late June, the journal Nature reported that if El Nino is severe, it has the potential to push global temperatures to record or near-record highs in 2024.
On July 4, the World Meteorological Organization concluded that the first El Nino phenomenon in the tropical Pacific Ocean in seven years, and the global will have destructive weather and climate patterns are almost certain.
The weather is sunny and hot, and the maintenance personnel must take sun protection measures when going out and replenish water in time. In addition, when spraying pesticide agents, we must try to avoid the high temperature period, because many agents are used in the high temperature period, on the one hand, it is very easy to appear drug damage, on the other hand, the effect is reduced.
Some drugs will cause harm at high temperature mainly due to the following two points:
1. it is related to the nature of the drug
Inorganic pesticides and water-soluble, permeable pesticides, such as copper sulfate, sulfur powder, stone sulfur mixture, used at high temperatures, it is very easy to cause drug damage to crops, because the structural stability of the chemical composition will change after a certain temperature, resulting in drug damage.
2. it is related to crop resistance
The drug resistance of leathery leaf plants such as Buxus macrophylla is stronger, and the drug resistance of plants with thin cuticle is weaker, and it is easier to produce drug damage when used in high temperature weather.
Next, take you to understand which agents need to avoid the use of high temperature time, so that you can avoid some unnecessary drug damage losses as much as possible!
These pesticides should avoid high temperature:
1. Organophosphorus pesticides: High temperature will decompose organophosphorus pesticides and reduce their effect.
2. Chloropyrethroid pesticides: High temperature will decompose chloropyrethroid pesticides, reduce its effect, but also produce toxic gases.
3. Fungicide: High temperature will reduce the stability of the fungicide, make it degrade, thereby reducing its bactericidal effect.
Specifically:
1. avermectin
Avermectin is a insecticide that kills insects, mites and nematodes, and can be used to control insect pests on a variety of plants. Avermectin insecticidal effect is good, about 20℃ when the use of good effect, but need to pay special attention to the high temperature is best not to use, especially 38℃ above the time of use, very easy to appear drug damage, resulting in plant leaves deformity, spots, stop growth phenomenon.
2. Ii. Pyrazoletin
Pyrazole ether ester is a broad spectrum fungicide, with therapeutic and protective effects, in the plant growth and high temperature period (above 37℃), high humidity conditions, if the use of pyrazole ether ester concentration is too high, there will be a risk of drug damage, is likely to cause plant leaf burning phenomenon.
3. Trienolamine
Enidine, insecticidal spectrum is relatively wide, mainly used to control stinging insects; It is easy to cause drug damage at high temperature, so when spraying, it is best to avoid high temperature, and it is better to choose a time period below 30 ° C to spray, so as not to cause leaf burning and other phenomena.
4. Tetraponitrile
Chlorfenil is a broad-spectrum insecticide, especially against the adult insects of lepidoptera (rapeseed, beet moth, etc.). Chlorfenil, suitable temperature about 20-30 degrees, the best effect. However, the use of chlorfenapyr at high temperatures may cause leaf burning; The more tender leaves on the top also have more serious drug damage.
5. Fluridine
Fluridine has good effect on higher fungi and lower fungi, can prevent downy mildew, gray mold, anthrax, black star disease; The prevention effect of blight, root swelling disease and gray mold is more prominent, and it can also prevent mite pests, such as citrus red spider (adult, egg), and the control effect is better. Fluridine, used in high temperature weather, will increase the chance of drug damage, because the activity of fluridine is very high, the permeability is very good, high temperature medication, will accelerate the evaporation of water, equivalent to increasing the concentration of the liquid medicine.
Therefore, the temperature suitable for application of fluridine is best at about 25 ° C, and the summer spray is chosen before 9 o 'clock in the morning or after 5 o 'clock in the afternoon, to avoid the high temperature period at noon, so as not to cause plant deformity and contraction.
6. Hexylene mite
Acetylene mite, low toxic acaricide, with contact and gastric toxicity, no inhalation and osmotic conduction. For adult mites, if the mites are effective, the ovicide effect is poor, generally 20℃ above the use of acetylene mite, the effect is good, but above 25℃, the plant fruit is very easy to produce sunburn disease.
7. butyl ether urea
Butyl ether urea is a new type of thiourea insecticide, acaricide, and has a certain effect of killing eggs. In the high temperature period (above 30℃) and high humidity conditions, the use of butyl ether urea is easy to produce drug damage to plant seedlings.
It should be noted that the suitable use temperature of the above agents is for reference only, and the specific temperature also needs to be divided into plants, and the suitable temperature of some plants is also different.
