What is the difference in the use of pesticides? Look here!
The same product, why is the effect so different?
Today, we will bring you a peasant uncle, but the crucial link is familiar to many of our agricultural friends, but are you using it correctly?
That is, the "second dilution method" of pesticides should be familiar to us. Farmers' uncles will use them every time they fight drugs. The second dilution method, also known as the two-step preparation method, first dilutes the pesticide preparation into a mother liquid or a mother powder with a small amount of water or a diluted carrier, and then dilutes to the desired concentration. This is the simple pesticide use step. Are you sure that your operation is correct?
Benefits of secondary dilution of pesticides
The second dilution method is used to prepare the pesticide liquid, which is first adjusted to a thick mother liquor with a small amount of water, and then diluted to the desired concentration, which has many advantages over the one-time dispensing.
1, can ensure that the drug is evenly dispersed in the water
For example, wettable powders and powders tend to agglomerate together to form coarse agglomerates. If the liquid is directly introduced into the solution tank, the coarse aggregates are not sufficiently dispersed, that is, they sink into the bottom of the water, and it is difficult to stir them at this time. If the dilution is directly used, the farmers' friends are not evenly stirred because of the medicine. The liquid is not completely dispersed in the sprayer, resulting in high concentration in some places and low concentration in some places, which is not conducive to uniform spraying. This is also the reason why all companies, including foreign companies with very high manufacturing processes, are also promoting secondary dilution.
Therefore, first use a small amount of water to form a thicker mother liquor, stir well, disperse the powder and then pour it into the tank for final dilution. The suspension of the suspension is prone to deposition during storage, that is, the upper layer gradually becomes thinner and the lower layer becomes thicker. The pharmaceutical solution must be prepared in a two-step process.
2, is conducive to accurate medication
With the development of efficient agriculture in recent years, only a few ten grams (or milliliters) or even a few grams of pesticide per acre is used, and the amount allocated to each sprayer is less. At this time, the two-step method is adopted to facilitate accurate drug taking. Such as wheat field herbicide "XXX", 8 grams of wettable powder for use, if sprayed on 45 kilograms of water, then only 2 grams per barrel (15 kg), not easy to weigh accurately in one preparation, and difficult to dilute evenly. Therefore, 8 grams of the original drug can be mixed with 600 grams of water to form a mother liquor, and then each barrel is diluted with 200 grams of mother liquor and 15 kilograms of water.
3, can reduce the risk of pesticide poisoning
For pesticides with higher toxicity, the second dilution method can reduce the chance of exposure to the original drug. For example, some pesticides with strong toxicity have a chance to contact the original drug four times in one dilution method, and only one time in the second dilution method. The possibility of poisoning is greatly reduced. Even if the liquid is contacted later, it is also a good mother liquor, poisoning. The probability is greatly reduced.
Therefore, the second dilution method is a technology that must be popularized in all pesticide use technologies, and it requires the joint efforts of the whole industry to advance. It is conservatively estimated that the effect of pesticide products without secondary dilution is at least 15%-20% lower than that of pesticide products with secondary dilution.
A diluted pesticide use method is a waste of pesticide resources and should be stopped. Powders, water-dispersible granules should also promote secondary dilution, as well as some water-dispersible granules coated with a dry suspension coat.
Principle of pesticide mixing
1. Mixing pesticides with different action mechanisms
Mixing pesticides with different action mechanisms can improve the control effect and delay the development of resistance to pests and diseases. For example, Qiling is a pyridazinone acaricide, which has a good control effect on Chengruo. Abamectin has a strong osmotic effect, and the two have a good synergistic effect, and have better control effect on citrus red spider.
2. Mixing pesticides with different modes of action
Insecticides have contact, stomach poisoning, fumigation, and internal absorption. The fungicides have protective, therapeutic, and systemic effects. If these drugs with different control effects are mixed, they can complement each other and produce good results. Control effect. For example, enoylmorpholine is highly systemic, and azoxystrobin has a good protective and therapeutic effect. The combination of the two has a broader spectrum of sterilization and higher efficacy.
3. Mixing insecticides that act on different insect states
The combination of insecticides acting on different insect states can kill various pests in the field, killing insects thoroughly, preventing recurrence, thereby improving the control effect. For example, tetracycline, which is strong in killing eggs, is mixed with avermectin, which can kill citrus aphid eggs and adults.
4, the effect of the difference in pesticide mix
The quick-acting effect is good, but the duration of effect is short; although the quick-acting effect is poor, the action time is long. The combination of two kinds of pesticides can not only serve the purpose of quick-acting insecticidal sterilization and weeding, but also achieve long-term control of the occurrence of pests and diseases.
5, mixed with disease, insects and pesticides
When several pests and diseases occur at the same time, the use of fungicides and insecticides can reduce the number of spraying and reduce the working time, thus improving the efficiency.
6, mixed with additives
Although pesticide additives have no direct toxicity to pests and diseases, they have strong penetrence, absorption and activity of pesticides, and the use of additives can reduce the effect.
Pesticide mixing order
1. General pesticide mixing sequence
Micro-fertilizer, water-soluble fertilizer, wettable powder, water-dispersible granules, suspending agent, microemulsion, water emulsion, water, emulsifiable concentrate are added in sequence (in principle, do not mix more than three kinds of pesticides), and each one is mixed, fully mixed and mixed. And then join the next one.
2, add water after adding the drug, the second dilution is indispensable
When mixing a variety of pesticides, it is recommended to add a large bucket of water to the sprayer, and then add the first pesticide and mix. Then, dilute the remaining pesticides with a plastic bottle, dilute them, pour them into the sprayer, mix them, and so on. (If you think the medicine is good, don't be lazy, the second dilution is very important!).
3, now with the current use, not suitable for a long time
No matter what kind of medicine is mixed, you should pay attention to "now available". Although any pesticide does not react when it is just blended, it does not mean that it can be left for a long time. Otherwise, it is easy to produce a slow reaction. If the pulverization is uneven and the dispersion is uneven, it is easy to stratify, and the effect is gradually reduced.
Method for secondary dilution of pesticides
The second dilution of pesticides is also known as the two-step preparation method and is one of the methods for pesticide formulation. The pesticide can be diluted twice by the following methods.
1. Use a medical saline bottle or other small container with a capacity scale, place the pesticide in the bottle, inject a proper amount of water into a mother liquor, and apply a small amount of viscous agent such as a suspending agent to the small package. After washing, gently stir to make the agent in the container fully disperse and dissolve, and then use the measuring cup.
2. When using a knapsack sprayer, it can be directly diluted in the barrel. First add a small amount of water to the sprayer, then add a proper amount of liquid medicine, shake well, then make up the water and mix well.
3, when using a motorized spray machine for large-area application, larger containers, such as barrels, cylinders, etc., can be used for primary dilution of the mother liquor. In the second dilution, it can be placed in the sprayer barrel for mixing and mixing.
Precautions for mixing pesticides
Although the mixture of pesticides has the benefits of reducing the amount of efficiency, delaying the resistance, etc., it is not necessary to mix the pesticides at random, otherwise the interaction may be lost and the medicinal damage may occur. Therefore, the following points must be noted when mixing pesticides.
1, does not cause physical changes
That is, after mixing, delamination, oil slick, flocculation, sedimentation or discoloration cannot occur, and no heat generation or bubble generation can occur. Generally, the same powder, or the same granules, fumigants, aerosols can be mixed; and water-based liquid agents such as wettable powder, emulsifiable concentrate, thick emulsion, suspension, water solvent, etc., should not be mixed .
2, does not cause chemical changes
1 Acidic pesticides must not be mixed with alkaline pesticides.
2 thiophanate-methyl and thiophanate can be complexed with copper ions and lose their activity.
3 dithiocarbamate fungicides, 24-D herbicides mixed with copper formulations can produce copper salts to reduce the efficacy.
4 Remove copper preparations, other preparations containing heavy metal ions such as iron, zinc, manganese, nickel, etc., should be especially careful when mixing.
Mixing 5 stone sulphur mixture with Bordeaux mixture can produce harmful copper sulfide and also increase the soluble copper ion content.
6 Enemy, butachlor and the like can not be mixed with organophosphorus and carbamate insecticides, and some chemical changes may cause phytotoxicity.
3. Pesticides with cross-resistance should not be mixed
For example, the fungicide carbendazim and methyl thiophanate have cross-resistance. Mixing not only does not delay the development of resistance to pathogens, but accelerates the development of drug resistance, so it cannot be mixed.
4. Biological pesticides cannot be mixed with fungicides.
The biological pesticide itself is a bacterium, a fungus or a chemical produced by it. Mixing it with a bactericide will definitely kill the active ingredients in the biological pesticide.