Detailed explanation of pesticide dilution and water exchange algorithm, how to correctly dilute pesticides?

As for the dilution problem in the process of pesticide use, many farmers said that they did not understand it. Today, the editor has sorted out a super-detailed pesticide dilution exchange algorithm for you. I hope it will be helpful to farmers. I must remember to collect it.

1. Dilution method: the percentage concentration refers to the number of parts containing medicine and fertilizer in 100 parts of medicine fertilizer liquid or medicine fertilizer powder, expressed as "%". For example, 2% urea means that there are 2 kg urea and 98 kg water in 100 kg urea solution.

Second, multiple concentration: refers to the multiple of water added to 1 part of pesticide, which is often expressed by weight. For example, the preparation of 700 times of 50% carbendazim is made by mixing 1 part of 50% carbendazim and 700 parts of water.

3. Conversion method: the conversion formula of percentage concentration to ppm concentration is as follows: 1 part of pesticide added with water = percentage of pesticide × 1000000 / number of ppm to be prepared. For example, 40% ethephon is compounded into 1 kg 2000ppm solution, and the amount of water added is 40 × 1000000 × 2000,200 phr.

Fourth, convert to multiple concentration: divide the percentage by the ppm number, move the decimal point backward 4 places, that is, the dilution multiple is obtained. For example, when 40% ethephon 1000ppm is converted into multiple concentration, 40 / 1000 / 0.04 is used, and the decimal point is moved back 4 places. That's 400 times.

Fifth, the method of mixing water: when several pesticides are mixed, water is not added for each drug, but all kinds of drugs are used: the same part of water is used to calculate the concentration. For example, to prepare 500x urea plus 1000 times methyl topiramate, use 2 parts of urea plus 1 part of methyl topiramine plus 1000 parts of water. In addition, when mixing water, the mother liquid should be prepared first, that is, the drug should be liquefied with a small amount of warm water, and then the water should be added to the required concentration and fully dissolved to improve the efficacy and prevent drug damage.

How to dilute pesticides correctly?

When using pesticide products, the mastery and configuration of pesticide concentration is related to the actual effect and effect of pesticide spraying, so diluting pesticides has become a key link in the use of pesticides, so how to correctly dilute pesticides?

(1) expression of drug concentration

1. Percentage concentration: refers to the number of active ingredients in 100 parts of pesticides, often expressed as (%).

2. Ppm concentration: refers to the number of active ingredients in 1 million pesticides, the symbol is PPm (or micrograms per milliliter; milligrams per liter; grams per cubic meter, etc.).

3. Multiple method (that is, dilution multiple): refers to the multiple of adding water or other diluents (fine soil, particles, etc.) when commercial pesticides are diluted. When diluting 100 times or less, one part of the original drug should be deducted from the calculation. If diluted 50 times, one part of the original drug plus 49 parts of diluent should be used. Dilution of more than 100 times, the calculation does not deduct the number of parts of the original drug, if diluted 600 times, that is, one part of the original drug plus 600 parts of the diluent.

(II) conversion between concentration representations

1. Conversion between percentage concentration and million concentration

Concentration per million (ppm) = 10000 × 100%

2. Conversion between multiple method and percentage concentration

Percentage concentration (%) = (original concentration / dilution multiple) x l00

(3) calculation method when diluting pesticides

1. According to the active ingredient:

(1) ask for the amount of diluent (water or filler, etc.)

① diluted less than 100x:

Diluent dosage = original agent weight x (original agent concentration-agent concentration) / agent concentration

More than 100x dilution of ②:

Diluent dosage = original agent weight x original agent concentration / mixed agent concentration

(2) ask for the dosage.

Original dosage = weight of the agent x concentration of the agent / concentration of the original agent

2. Calculated according to the multiple method (without considering the content of active ingredients):

(1) less than 100 times dilution

Diluent dosage = original agent weight × dilution multiple-original agent weight

(2) more than 100 times dilution

Diluent dosage = original reagent weight × dilution multiple

(3) ask for the dosage.

Original dosage = weight of the agent / dilution multiple

(4) calculate the dilution multiple.

① calculates the dilution multiple from the concentration ratio:

Dilution multiple = original agent concentration / agent concentration

The dilution multiple of ② is calculated by weight ratio:

Dilution multiple = weight of the agent / weight of the original agent

twelve