Characteristics of several common fungicides

Bordeaux liquid is a good protective fungicide, which is made of copper sulfate, quicklime and water. According to the different dosage of copper sulfate and quicklime, Bordeaux liquid can be divided into equal type (1:1), half-quantity type (1 0.5), multi-quantity type (1:3) and double quantity type (1:2). When preparing, first use half of the hydration of copper sulfate and quicklime, and then pour copper sulfate into the quicklime solution, and stir evenly with a stick. The Bordeaux solution is sky blue colloidal suspension, alkaline, strong adhesion, can form a film on the plant surface, the validity period can be maintained for about half a month. Bordeaux liquid is not resistant to storage and must be used now and should not be mixed with alkali pesticides. It can prevent and cure many diseases such as black spot, rust, downy mildew, gray spot and so on.

Second, the stone-sulfur mixture is also a protective fungicide, which is made from quicklime, sulfur powder and water at the proportion of 1:2:10. The original liquid is a dark reddish-brown transparent liquid, which smells of rotten eggs and is alkaline. When preparing, first boil the water in the pot, pour in 1 part of quicklime, wait for the lime to dissolve, then add 2 portions of sulfur powder which is first adjusted into paste with a small amount of water, add and stir, add and boil with high fire for about 1 hour, cease fire when the solution is reddish brown, after cooling, filter out the sediment, that is, the original solution of stone sulfur mixture, and its Baume filling degree is generally 20-24. The original solution must be diluted before use. Baume 3-5 degrees can be used for spraying in the dormant period, and only 0.3-0.5 Baume dilution can be used in the growing period. It can control powdery mildew, rust, downy mildew, perforation, leaf spot and other diseases, as well as whitefly, leaf mites, scale insects and other pests.

Third, chlorothalonil has protective and therapeutic effects, has a wide range of sterilization, has a long residual period, and has a stimulating effect on skin and mucosa. Commonly used 75% chlorothalonil wettable powder 600-1000 times liquid spray to control rust, downy mildew, powdery mildew, black spot, charcoal disease, blight and other diseases. It should not be mixed with strongly alkaline pesticides.

4. Carbendazim is a high-efficient, low-toxic, broad-spectrum internal inhalation fungicide with protective and therapeutic effects and a long residual period. Generally, 50% wettable powder 1000-1500 times is sprayed to control diseases such as brown spot, Sclerotinia sclerotiorum, anthracnose, powdery mildew and so on. Seed dressing and soil disinfection can also be used.

5. Topiramate is a kind of internal inhalation fungicide with high efficiency, low toxicity and broad spectrum, which has protective and therapeutic effects, has a long residual period, has a bactericidal range and efficacy similar to carbendazim, has low toxicity to humans and animals, and is safe to plants. Commonly used 50% wettable powder 500-1000 times liquid spray to control powdery mildew, anthrax, coal pollution, white silk disease, Sclerotinia sclerotiorum, leaf spot, gray mold, black spot and other diseases, as well as methyl topiramate.

6. Dysen zinc is a broad-spectrum organic sulfur fungicide with a light yellow color and a slight odor. it is easy to decompose in the air or in the sun. 65% wettable powder 400-600 times is commonly used to control brown spot, anthrax, quenching, perforation, gray mold, powdery mildew, rust, leaf blight, bacterial blight, etc., and should not be mixed with alkaline or agents containing copper and mercury.

Tuijiete is a mixture of organic arsenic and organophosphorus fungicides, white powder, insoluble in water, easy to dissolve in alkaline solution, easy to decompose in acidic high temperature and humid environment. Generally, 50% WP 1000-1500 times or 80% WP 2000-2500 times are sprayed to control anthracnose, rust, bacterial blight, powdery mildew, Sclerotinia sclerotiorum and other diseases.

8. Benzoate is a broad-spectrum internal absorption fungicide with both protective and therapeutic effects, insoluble in water, slightly irritating odor and long-term efficacy. 2000-5000 times of 50% wettable powder is commonly used to control diseases such as Botrytis cinerea, anthrax, powdery mildew, Sclerotinia sclerotiorum, etc.

9. Dysenamine has strong germicidal efficacy and has both protective and therapeutic effects. After decomposition, it also has a certain fertilizer effect, showing a light yellow liquid. 1000 times liquid is often used to spray to control powdery mildew, downy mildew and leaf spot.

Ten, streptomycin is a white powder, generally with 100-200 mg per liter concentration spray, root irrigation or injection, prevention and control of bacterial diseases, downy mildew and so on. (Xu Maojin)