Precautions for Spraying Pesticides to Control Diseases, Pests and Weeds in Summer and Pesticide Mixing

In the process of agricultural production, crops are often harmed by various pathogens, insect pests and weeds, which leads to reduced yield and deteriorated quality, causing farmers to suffer reduced harvests and economic losses. Therefore, when spraying pesticides in summer to control diseases, pests and weeds, attention should be paid to the following points:

1. Avoid spraying at midday when temperatures are high and light is intense. When chemical pesticides are sprayed around noon, when the temperature is at its highest and the light is at its strongest, first, the pesticide is highly volatile, which can very easily cause poisoning of the applicator; second, most pests hide in cool, shaded places, so the spray is not easily able to hit the target, and at the same time the pesticide decomposes quickly and volatilization losses are large, so the pest control effect is not ideal.

2. Choose a rain-free cloudy day for spraying. If it is a sunny day, seize the time after sunrise from 8-10 a.m. or after 5 p.m. before sunset when there is no dew, when pests are most active, to spray. When the wind is relatively strong, spraying should be stopped; otherwise it will cause uneven spraying and can also easily cause pesticide damage.

3. When spraying pesticides in summer, attention should be paid to personal protection, and contact between pesticides and the skin should be avoided as much as possible.

4. Do not arbitrarily increase the concentration of the pesticide solution. Some farmers, in order to improve work efficiency or out of consideration for enhancing the control effect, often increase the amount of pesticide used, reduce the pesticide dilution ratio, and arbitrarily increase the concentration of the solution, even in the hot summer season. Because water evaporates very quickly under the hot sun and high temperatures, if the concentration of the sprayed pesticide is too high, it can very easily cause chemical damage to plant leaves.

5. Choose fast-acting pesticides. Pesticides such as dichlorvos, fenpropathrin, procymidone and phoxim-cypermethrin EC have strong toxic effects and can kill pests 1-2 hours after use. Choose pesticides with strong systemic action. Pesticides such as dimethoate, methomyl and metalaxyl can, 4-5 hours after use, have more than 80% of their active ingredients absorbed into the internal tissues of the crop, so even if it rains, pests and pathogens can still be killed.

6. Add adhesives to water-based and wettable powder pesticides. Water-based and wettable powder pesticides have poor adhesion. When preparing pesticides, add 100-150 grams of soybean flour or washing powder, or two bags of Jiamei Golden Point as a synergist, per 100 kg of pesticide solution to improve the effectiveness of the pesticide.

7. Determine the safe interval before spraying according to the toxicity of the pesticide. Generally, the residual effective period of highly toxic pesticides is more than 1 month, and the residual effective period of highly efficient 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.

Therefore, when applying pesticides in the hot summer season, even more attention should be paid to mixing enough water and ensuring the dilution ratio. The amount of pesticide solution used per mu must be more than 45 kg. Do not overfill the tank with pesticide solution. When spraying, some farmers like to fill the sprayer tank very full with pesticide solution. This is not only unfavorable for spraying, but more importantly, if the sprayer lid is not tightly sealed, the pesticide solution may splash out and get onto the body when the applicator walks in the field, and in the hot season this can very easily cause poisoning. The correct approach is that when mixing the pesticide, the upper liquid level in the tank should be below the scale line, and the sealing ring of the lid must be intact to ensure the lid is tightly sealed.

Several common situations for pesticide mixing:

Pesticide mixing is a common method of pesticide use. For convenience and to save labor, farmers often mix several pesticides together when controlling diseases and pests. Not all diseases and pests require pesticide mixing. Below, the editor summarizes several common situations in which pesticide mixing is needed.

1. To achieve the purpose of disease prevention or enhance plant disease resistance, promote plant growth or cultivate strong seedlings;

For example, after mixing the growth hormone 2,4-D with fungicides for controlling gray mold (fludioxonil, pyrimethanil, etc.), smear it on tomato flower buds (also called flower dipping);

2. When more than one disease occurs on the same crop at the same time, pesticide mixing can be carried out;

For example, on cucumbers grown in protected cultivation, whiteflies or aphids often occur at the same time as downy mildew and gray mold, so pesticides for controlling whiteflies or aphids (imidacloprid) are usually mixed with pesticides for controlling downy mildew (metalaxyl-M · mancozeb) or pesticides for controlling gray mold (iprodione, nicotinamide, fludioxonil, etc.).

At present, common pesticides on vegetables, such as trichlorfon, dichlorvos, carbofuran, deltamethrin, fenvalerate, zineb, thiophanate, thiram, carbendazim, chlorothalonil, metalaxyl, phosethyl-Al, captan and so on, can all be mixed and used according to the needs of disease and pest control.

Not all pesticide mixtures are effective. Pesticide mixing requires attention to the following points:

1. Pesticides being mixed must not undergo chemical changes;

2. Pesticides being mixed must not increase toxicity;

3. The physical properties of the mixed pesticides should remain unchanged;

4. Mixed pesticides should have different mechanisms of action or different control targets.

Finally, a warm reminder from the editor: pesticide mixing must be done with caution, especially for some strongly acidic and strongly alkaline pesticides, to avoid reducing efficacy and causing pesticide damage. Therefore, before using pesticides, read the label in detail, and conduct a small-area trial before using them over a large area.