The "second dilution method" of pesticides should be familiar to who work in agriculture. Farmers use it every time they take medicine. Secondary dilution method, also known as two-step preparation method, is to dilute pesticide preparations into mother liquor or mother powder with a small amount of water or dilution carrier, and then dilute to the required concentration. How many people are using pesticides correctly in this simple procedure?

The most scientific use of pesticides - the second dilution method, the whole pesticide industry, including foreign enterprises, are in a wide range of publicity, encourage farmers to second dilution, in order to improve the utilization rate and use effect of pesticides. The second dilution method of pesticides is mainly used to dilute (prepare) those pesticides with very little dosage. The dosage of these pesticides is even less than 1 gram per mu. Only through the second dilution (preparation) can the pesticides be evenly mixed and easy to use.

 

  Benefits of secondary dilution of pesticides

 

  The second dilution method for preparing pesticide liquid is to firstly use a small amount of water to make the liquid into a thick mother liquor, and then dilute it to the required concentration. It has many advantages over the one-time preparation.

 

  1. It can ensure the uniform dispersion of medicines in water.

 

  For example, wettable powders and powders are often agglomerated to form coarse aggregates. If they are directly put into a liquid dispensing tank for one time, the coarse aggregates will sink to the bottom before they are fully dispersed. It is very difficult to stir them again at this time. If a dilution is used directly, it may not evenly stirred since the mixture is not evenly distributed. The concentration of the solution 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 spray. This is why all enterprises, including foreign enterprises with very high manufacturing technology, are also advocating secondary dilution.

  Therefore, a small amount of water is used to prepare a thicker mother liquor, which is fully stirred to disperse the powder and then poured into the medicine tank for final dilution. It is easy for the suspension to deposit during storage, that is, the upper layer becomes thinner and the lower layer becomes thicker. Two-step method must be adopted in the preparation of pharmaceutical solution.

  2. Favorable for Accurate Drug Use 

  With the development of high efficiency agriculture in recent years, only a few grams (or milliliters) or even a few grams of pesticide is needed per mu, and the amount allocated to each sprayer is less. At this time, two-step preparation is conducive to accurate drug extraction. If the wheat field herbicide "XXX" is sprayed with 8 grams of wettable powder per mu and 45 kg of water, only 2 grams of herbicide per barrel (15 kg) is used. It is not easy to weigh accurately and dilute uniformly in one preparation. Therefore, the mother liquor can be prepared by adding 600 grams of water to 8 grams of the original drug, and then diluted by adding 15 kg of water to 200 grams of mother liquor per barrel

  3. Reducing the risk of pesticide poisoning

  For pesticides with high toxicity, the second dilution method can reduce the chance of contact with the original drug. For example, some highly toxic pesticides, one-time dilution method has four opportunities to contact the original drug, while the second dilution method only once, the possibility of poisoning is greatly reduced, even after contact with the liquid, it is also a blended mother liquor, the probability of poisoning is greatly reduced

  Therefore, the second dilution method is a technology that must be popularized in all pesticide use technologies, and it also needs the joint efforts of the whole industry to promote. Conservatively, the performance of pesticide products without secondary dilution is at least 15% - 20% worse than that of pesticide products with secondary dilution.

  One-time dilution of pesticides is a waste of pesticide resources, which should be stopped. The second dilution should be advocated for powder and water dispersible granule, including some water dispersible granule products coated with dry suspension agent.

  Method of second dilution of pesticides

  Secondary dilution of pesticides, also known as two-step formulation, is one of the methods of pesticide formulation. The following methods can be used for secondary dilution of pesticides.

  1. Select medical saline bottles or other small containers with capacity scale, place pesticides in the bottle, inject appropriate amount of water into mother liquor, wash the medicines adhering to small packages, gently agitate to make the container fully dispersed and dissolved, and then use the dosage cup to measure

  2. When using the knapsack sprayer, it can be diluted two times in the medicine barrel directly. First add a small amount of water to the sprayer, add the right amount of medicine, shake well, then add enough water to mix.

 

  3. When spraying a large area with a mobile spraying machine, a larger container, such as a bucket or cylinder, can be used to dilute the mother solution. Two levels of dilution can be placed in the sprayer barrel for mixing and mixing.    

  Note: In order to ensure the quality of dilution, the amount of water used in the preparation of mother liquor should be carefully calculated and meticulously measured. It should not be used more or less at will, otherwise it will directly affect the control effect.

 

Guangzhou Liwei ● This article is reprinted from Report on Agricultural Resources Pesticides