What precautions should be taken when spraying pesticides in hot weather?
Summer is a period of vigorous growth for many plants, and it is also the peak period of damage from various pests and diseases. Rising temperatures also make it inconvenient to spray crops and can easily cause pesticide damage. So what precautions should be taken when spraying pesticides in hot weather?
1. Avoid high temperatures and strong light
During high temperatures and strong light, most pests hide in cool, shaded places. At this time, spraying is unlikely to hit the target, and pesticides decompose quickly, with large volatilization losses and poor pest control results; in addition, the strong volatility of the pesticide can easily cause poisoning among applicators.
2. Better results at lower temperatures and when it is not raining
On cloudy and rainy days without strong sunlight, pests that are active at night often crawl out to damage crops, so cloudy weather without rain is a good time to kill pests. At the same time, spraying rain-resistant fungicides in cloudy and rainy weather, such as emulsifiable concentrates or suspension concentrates, can effectively reduce the number of pathogens and also reduce waste caused by rain washing.
If it is a sunny day, spray after sunrise from 8-10 a.m. or before sunset after 5 p.m. when there is no dew. At this time, pests are more active and the insecticidal effect is good; windy weather will cause uneven spraying and easily lead to pesticide damage, so spraying should be stopped at this time.
3. Do not change the concentration of pesticides casually
In summer hot weather, water volatilizes quickly. If pesticides are sprayed at too high a concentration at this time, it is very easy to cause pesticide damage to crop leaves. Therefore, farmers and friends should not blindly increase the amount of pesticide, reduce the dilution factor, or increase the concentration of the spray solution in order to improve spraying efficiency or enhance control effects, especially in the hot summer season.
4. Add adhesives to water-based and wettable powder pesticides
When preparing pesticides, add 100-150 grams of soybean powder or washing powder, or two bags of Jiamei Jindian, as a synergist to every 100 kg of spray solution. This can improve the adhesion of water-based and wettable powder pesticides and enhance their effectiveness.
5. Determine the safe interval before spraying according to pesticide toxicity
Generally, the residual effect period of highly toxic pesticides is more than 1 month, and the residual effect period of high-efficiency, low-toxicity pesticides is 7-10 days. Whether for grain, oil crops, melon crops or fruit trees, pesticide use should be stopped according to regulations before harvest to prevent poisoning of people and livestock.
When applying pesticides in hot summer weather, be sure to add enough water according to the pesticide instructions, ensure the dilution factor, and ensure that the amount of spray solution per mu is more than 45 kg. At the same time, choose an appropriate time period for spraying and take good personal physical protection. When mixing pesticides, the upper liquid level of the spray solution in the barrel should be below the scale line, and the sealing ring of the lid must be intact to ensure the lid is tightly closed. Avoid splashing pesticide solution onto the body and causing poisoning.
6. Choose pesticides with quick action or strong systemic activity
For example, quick-acting pesticides such as dichlorvos, fenpropathrin, procymidone, and phoxim-cypermethrin emulsifiable concentrate have strong toxic effects and can kill pests within 1-2 hours after use. For pesticides with strong systemic activity, such as dimethoate, methomyl, and metalaxyl, more than 80% of the active ingredient can be absorbed into the internal tissues of crops within 4-5 hours after use, and pests and pathogens can still be killed even if it rains.
7. Mistakenly believing that the closer the nozzle is to the target, the better the effect
Many people think that the closer the nozzle is, the less pesticide is wasted and the better the effect. This is wrong. Large droplets will cause pesticide damage to crops. Within a certain distance range, the farther from the nozzle, the smaller the droplets. In this way, small droplets are more likely to deposit and spread on the target. Everyone should pay more attention to this when spraying.