In order to prevent tomatoes from falling, fruit-setting hormones used in production are 2,4-d and anti-deceasing hormone. Farmers should pay special attention to the following points in their use: 1, the use of concentration: 2,4-d use concentration is generally 10ppm-20ppm, the use of anti-dropping agent concentration is generally 20ppm-40ppm, take the lower limit of the concentration of high-temperature, low-temperature concentration when the limit. Before the use of the flower test should be carried out first, picking up a few normal flowers, if 4-5 days after the ovary began to expand, that the concentration is appropriate; if within 3 days the ovary began to enlarge, indicating that the concentration is too high; if a week No ovary enlargement was observed, indicating that the concentration was too low. 2, the use of time: when the flowers to the top of the flower to see the yellow and not fully open or when the flowers are the best shape. It is easy to cause burnout prematurely, but it does not work until the flowers are lantern-shaped. In the sunny afternoon, it is better to have flowers in the morning, because the condensation of the plant surface will cause the concentration of the liquid to change and produce phytotoxicity. 3, the treatment site: with a brush to mix the light solution on the pedicel or pedicel, or dip the entire inflorescence in the solution, do not sprinkle the solution on the young leaves or growing points when processing, otherwise it will make The leaves become bar-shaped fern leaves that grow slowly, especially 2,4-d, and are most susceptible to phytotoxicity. 4, fertilizer and water supply: the use of hormones to prevent flowering flowers, promote fruit hypertrophy, but no fertilizer effect. Therefore, after using hormones, it is necessary to scientifically and reasonably top-dress and strengthen management. In addition, after the first fruit is used with fruit hormone, all other fruit should be used. Otherwise, the following fruits will absorb nutrients in a large amount, and the upper ear will not get the necessary nutrients. Disclaimer: Some articles in this website have been transferred from the Internet. If you are involved in third party legal rights, please inform this website. phone
Preparation of Fenebute
1. Prepare the first intermediate
Benzaldehyde and ethyl acetoacetate into ethanol, stir at room temperature under the catalysis of organic alkali reaction with filter cake filtration after 45 ~ 50 h, after the completion of the filter with ethanol elution filter cake, dry cake solids, then ethanol filtrate concentrated to a quarter of the original volume, to cold, concentrate filtering alcohol washing, solid, merging two solid is the first intermediate; The mole ratio of benzaldehyde, ethyl acetoacetate and ethanol is 1:2.5 -3:12-15.
2. Prepare the second intermediate
The first intermediate is added to the mass concentration of 20% sodium hydroxide solution, and the reaction is stirred at 85-90°C for 2-5 hours. After filtration, the filter cake is used for filtration. After filtration, the filter cake is washed, the filtrate is combined and cooled, and the filtrate is cooled by stirring for 3h. Solid second intermediate; The mass ratio of the first intermediate to the sodium hydroxide solution is I: 1.8-2.0;
3. Prepare the third intermediate
The second intermediate was dissolved in pure acetic anhydride solution for reflux 3 ~ 5h. After the reflux, the acetic anhydride was concentrated and dissolved with toluene. After the dissolution, ammonia water was added, and the reaction took place at 60_65°C for 1 ~ 1.5 h. Filtrate, wash and dry the precipitated solid to get the solid third intermediate; The mass ratio of the second intermediate, pure acetic anhydride solution, toluene and ammonia water is 5:1-1.2:0.5-0.8:0.5-0.8;
4. Prepare Finebute
The third intermediate was dissolved in 25% sodium hydroxide solution and cooled to _5°C ~ 10°C. After cooling, sodium hypochlorite was added slowly within 15-20min for 1h reaction, followed by ice bath reaction of 0.5 ~ 1.5 h and water bath reaction of 0.5 ~ 1.5 h. Finally, the temperature was gradually increased to 60 ~ 80°C for 1-5 h, and the reaction was cooled again after completion. After cooling, hydrochloric acid was added in the ice water bath to adjust the PH to 2, and the decolorization was stirred at room temperature. After filtration, sodium hydroxide was added in the ice water bath to adjust the PH to 6-7, and the cooling was stirred for 2 hours. The mass ratio of the third intermediate, sodium hydroxide solution and sodium hypochlorite is 1.0:0.8-1.0:1.0-1.1.
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