Thiophanate methyl, chemical formula CtwelveHfourteenNfourOfourStwoIt is a broad-spectrum internal absorption low toxicity bactericide with internal absorption, prevention and treatment effects.It was originally developed by Caoda Co., Ltd. in Japan, and can effectively control a variety of crop diseases.
1. Preparation of methyl chloroformate: methyl chloroformate is synthesized from methanol and phosgene at 5~15 ℃. Phosgene is easy to decompose in water, so pay attention to dryness. If the temperature is too high, it is easy to generate by-productsDimethyl carbonate。
2. Preparation of methyl isothiocyanate:acetoneAs a solvent, methyl chloroformate is prepared by reacting with sodium thiocyanate.The reaction temperature should be well controlled. If the temperature is too high, the isothiocyanate ester is easy to decompose, and the isomerization is not easy to occur at a low temperature. Generally, 45~59 ℃ is appropriate.Note that when dropping methyl chloroformate, the temperature is too high, and it is easy to boil and overflow, so 38 ℃ is appropriate.
3. Synthesis of thiophanate methyl: thiophanate methyl was prepared by addition of o-phenylenediamine and methyl isothiocyanate at 15~40 ℃.Strictly control the ratio of raw materials to 1: 2.
toxicology data
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Acute oral LD in ratsfifty: 6640~7500mg/kg, mouse acute oral LD50: 3150-3400mg/kg;Acute percutaneous LD in rats and micefifty：> 10000mg/kg；Carp LCfifty：11mg/L（48h）；Cicada LCfifty：8.8mg/L；Low toxicity to bees.
Features: broad-spectrum bactericide, with apical transmission function, has preventive and therapeutic effects on many diseases.It has inhibitory effect on leaf mites and pathogenic nematodes.
Scope of application: It has good control effect on many diseases of cereals, vegetables and fruit trees.
usage method
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1. Prevention and control of vegetable diseases: prevent and control cucumber powdery mildew, anthracnose, eggplant, onion, celery, tomato, bean and other gray mold, anthracnose, sclerotinia, and 50% wettable powder 1000-1500 times liquid, spray once every 7-10 days at the beginning of the disease, and spray 3-4 times continuously;To control lettuce gray mold and sclerotinia disease, 50% wettable powder can be sprayed with 700 times liquid.
2. Prevention and control of flower diseases: it has certain control effect on dahlia flower rot, rose brown spot, Begonia gray spot and Clivia leaf spot.Generally, at the beginning of the disease, 83-125g of 50% wettable powder per mu is sprayed with water for 3-5 times.
3. Prevention and control of fruit tree diseases: apple ring rot and anthracnose can be sprayed with 400-600 times of 50% wettable powder every 10 days;Grape brown spot, anthracnose, grey mold, peach brown rot, etc., can be sprayed with 50% wettable powder 600-800 times liquid;For penicillium and green mold in the storage of citrus, use 400 to 600 times of 40% gum suspension immediately after picking the citrus, soak the fruit for 2-3 minutes, remove it, dry and frame it.
4. Prevention and control of wheat diseases: wheat head smut can be treated with 200g of 50% wettable powder, 4kg of water and 100kg of seeds, and then the seeds can be kept for 6 hours;Three wheat scab, spray once at the beginning of flowering period, and spray the second time after 5-7 days, and use 75-100 grams of 50% wettable powder per mu each time.
5. Prevention and control of other crop diseases: tobacco and mulberry powdery mildew can be sprayed with 50% wettable powder 300-400 mg/kg;Peanut leaf spot disease can be sprayed with 50% wettable powder 200-250 mg/kg solution for 3 times at an interval of 2 weeks during the peak period of disease;For sweet potato black spot, 50% wettable powder 500-1000 mg/kg solution can be used to soak seed potatoes for 10 minutes.
matters needing attention
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It cannot be mixed with alkaline and inorganic copper agents.Long term single use is easy to produce resistance and has cross resistance with benzimidazole fungicides, so attention should be paid to the rotation with other agents.If the medicine liquid splashes into the eyes, it can be washed with clean water or 2% soda water.
