When are pesticides used in hot days? What are the precautions of spraying pesticides in summer?

Recently, many peasant friends often ask Xiaobian how to spray pesticides in hot weather, which can not harm crops but also give full play to their efficacy. Now the editor will give you a detailed account of the following points that should be paid attention to when spraying pesticides to control diseases, insects and weeds in high temperature weather in summer:

First, it is necessary to avoid spraying in high temperature and bright light at noon

Spraying chemical pesticides around noon when the temperature is high and the light is strong, first, the chemical is highly volatile, which is very easy to cause poisoning to the application personnel; second, most of the pests hide in the cool backlight, and the spray is not easy to hit the target. At the same time, the pesticide decomposes quickly and volatilizes a lot, so the effect of insect control is not ideal.

Second, you can choose to spray on cloudy days without rain.

If it is a sunny day, spraying should be done between 8 am and 10:00 after sunrise or after 5 pm when there is no dew before sunset and when pest activity is booming. When the wind is strong, you should stop spraying, otherwise it will cause uneven spraying and easy to cause drug damage.

Third, when spraying pesticides in summer, you should pay attention to physical protection and avoid contact with the skin as far as possible.

Fourth, do not increase the concentration of the solution at will

In order to improve the work efficiency or to enhance the control effect, some farmers often increase the amount of pesticides, reduce the dilution multiple of pesticides, and increase the concentration of the liquid at will, even in the hot season in midsummer. Due to the rapid volatilization of water in the hot sun, if the concentration of pesticide sprayed is too high, it is easy to cause chemical damage to plant leaves.

5. Choose pesticides with quick effect and strong internal absorption

Pesticides such as dichlorvos, thalidomide, trimethoprim and cyanocyanide EC have strong toxic effect, and the pests will be eliminated within 1-2 hours after use. Choose pesticides with strong internal absorption, such as dimethoate, Metalaxyl and so on, 4-5 hours after use, more than 80% of the active ingredients can be absorbed by crops into the internal tissue, even if rain can still eliminate pests and germs.

Add adhesives to water agents and wettable powder pesticides

The adhesion of pesticides is poor. When preparing pesticides, adding 100-150 grams of soybean powder or washing powder or two bags of Jiamejin points as synergists can improve the effect of pesticide use.

7. Determine the safe interval of spraying according to the toxicity of pesticides.

Generally, the residual period of high toxic pesticides is more than 1 month, and that of low toxic pesticides is 7-10 days. No matter grain, oil, melon crops and fruit trees, the use of drugs should be stopped before harvest in order to prevent human and animal poisoning.

Therefore, in the summer high temperature season, we should pay more attention to enough water to ensure the dilution multiple, the amount of liquid per mu is more than 45 kg. Taboo bucket is too full, some farmers like to spray the liquid in the sprayer bucket is very full. This is not only disadvantageous to spraying, but more importantly, if the cover of the sprayer is not tightly closed, the liquid will spill and touch the body when the sprayer is walking in the field, which can easily cause poisoning in the hot season. The correct way is that when dispensing, the upper surface of the liquid in the bucket should be below the scale line, and the sealing ring of the lid is intact to ensure that the lid is closed tightly.

VIII. Rational mixing of pesticides

The mixed use of pesticides can be carried out when more than one disease occurs on one crop at the same time. For example, whitefly or aphids, downy mildew and gray mildew often occur simultaneously on cucumbers cultivated in protected areas. the insecticides for the control of whitefly or aphids (imidacloprid) are usually mixed with those for downy mildew (Metalaxyl + mancozeb) or for the control of Botrytis cinerea (isocarbamide, nicotinamide, chlorphenicol, etc.).

The mixed use of pesticides should pay attention to the following points:

(1) the mixed pesticides can not undergo chemical change.

(2) the mixed pesticides can not increase the toxicity.

(3) the physical properties of mixed pesticides should remain unchanged.

(4) mixed pesticides should have different action mechanisms or different control objects.

Editor warm hint: pesticide mixed use should be cautious, especially for some strong acid, strong alkali pesticides should pay more attention to, so as not to reduce the efficacy and cause drug damage. Therefore, it is necessary to read the label carefully before using pesticides, and use it in a large area after a small trial.