Several major problems in the mixing of pesticides in agricultural production

In agricultural production, in order to improve the control effect of pests and diseases and reduce the work intensity, a variety of products are usually used in combination. Scientific and rational pesticide mixing can expand the scope of prevention, improve drug efficacy, reduce the number of prevention and control, and delay the development of resistance to pests. However, if mixed improperly, it will lose its effectiveness.

Therefore, it is necessary to pay attention to the problem that the active ingredients are not destroyed and the physical properties of the liquid medicine are not deteriorated. However, the problem of phytotoxicity caused by improper compounding is also very serious.

The phytotoxicity of plants is divided into acute phytotoxicity and chronic phytotoxicity according to symptoms:

Most of the acute phytotoxicity symptoms appear in a short period of time, manifested as yellowing, chlorosis, leaf rolling, fallen leaves, withered and Other symptoms.

Chronic phytotoxics generally show symptoms of phytotoxicity after a long period of time, such as affecting flower bud differentiation, leaf, fruit and other organ malformations, short plants, and imperfect grain.

First, the order of mixing is improper

Many farmers simply blindly mix all the products together after they know that they can be mixed, resulting in uneven mixing and even reaction, resulting in phytotoxicity.

The dosage forms of pesticides are different, the solubility is also different, and the order of compounding is also different.

First, wettable powder

Take 1 part of wettable powder, add 200 parts of water, hold in a glass cup, shake it for a certain period of time, observe the suspension. If the drug precipitates slowly, the suspension is good. In case of poor quality, silicone additives or neutral detergents should be added before use to increase wet spread. If the wettable powder absorbs moisture and is hard, it should not be used as a spray.

Second, suspending agent

Third, the water agent

Fourth, emulsifiable

In the process of storage of emulsion pesticides, if they are not properly stored, the following three conditions may occur.

1. Agglomeration.

If the emulsified concentrate has a non-flowing viscous liquid or has formed a soapy solid, it proves that the solvent has been mostly volatilized and the quality has changed and cannot be used.

2. Precipitation crystallization.

For long-term storage of the emulsion, there will be white crystals on the bottom of the bottle or turbidity. If the emulsified milk bottle is immersed in warm water of 30-40 ° C, the crystallization will melt in about 30 minutes and return to a transparent liquid, indicating that the quality is still good and can be used. If it does not dissolve, it indicates that the quality of the cream has changed and cannot be used.

3. Changes in the emulsifying properties of the cream.

Take 1 part of emulsifiable concentrate, add 200 parts of water, put it in a glass cup, shake it and let it stand for about half an hour. Observe the emulsification. If there is no oil slick in the upper layer, there is no precipitation in the lower layer, no obvious oil beads in the middle, indicating that the emulsification performance is good; There is emulsifiable concentrate, there is sediment underneath, and there is delamination after 10 minutes, indicating that the emulsion is destroyed and cannot be used.

For the blending of foliar fertilizers and pesticides, it is necessary to first foliar fertilizer and then add the pesticide in the order of compounding.

Second, do not pay attention to the second dilution

In order to save trouble, many farmers choose to pour the medicine directly into the medicine bucket at one time, and do not pay attention to the second dilution, resulting in uneven liquid medicine and phytotoxicity. Whether it is foliar fertilizer or pesticide, the solubility is different, the most reasonable method is:

First add half of the water in the spray equipment, then dilute the pesticide, add the medicine bucket, pay attention to the mixing, and so on.

Third, a variety of product mix

In order to reduce the workload, many farmers use a variety of fungicides and pesticides . In general, for products that can be compounded, up to three combinations of products of different dosage forms are available. If there are too many products to be mixed, complex reactions are likely to occur and phytotoxicity occurs.

At the same time, it should be noted that the mixed use of two pesticides cannot be equated with the compound pesticides;

It is already a compound product, and it is not recommended to mix it with other medicines. If the operation is wrong and the phytotoxicity has already occurred, it needs to be remedied to mitigate the hazard.

(1) The time of occurrence of phytotoxicity is short. After timely discovery, it is necessary to spray a large amount of water on the leaf surface in time to rinse off the residual liquid to reduce the harm.

(2) For the phytotoxicity caused by the foliar surface, or the yellowing caused by the phytotoxicity, fertilizer can be added to promote the root development of the crop and enhance the crop resilience. For example, after the emergence of chlorsulfuron-methyl in wheat, the plant growth is promoted by topdressing urea + Potassium Dihydrogen Phosphate.

(3) For the crop after the victim. It is necessary to cultivate the loose soil to enhance the self-recovery ability of the crop; it is necessary to trim the dead branches and reduce the infection of the bacteria.

Be sure to pay attention to the use of pesticides. In the case where it is not possible to determine whether it is possible to mix, try not to mix, or a small amount of experiment, if there is a reaction or delamination, the mixing cannot be performed.

More pesticide knowledge , please pay attention to China Pesticide Network

(Source: China Agricultural Resources Network)

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