First, the type of biological pesticides
There are many types of microbial pesticides, and more than 2,000 kinds have been discovered. According to the classification of microorganisms, they can be classified into bacteria, fungi, viruses, protozoa and nematodes. At present, domestic research and development and application of commercial products mainly include bacterial insecticides, fungal insecticides, viral insecticides and antibiotic insecticides.
Biological insecticides are mainly divided into three major categories: Bacillus thuringiensis, insect virus, and plant extract. They are characterized by convenient materials, low cost, long control period, high efficiency, economy, safety, pollution-free, and high compatibility with the environment. It is the best pesticide choice for the production of pollution-free green vegetables.
1, bacterial insecticide
Bacterial insecticides are the earliest and most widely used microbial insecticides in domestic research and development. At present, the varieties studied and studied include Bacillus thuringiensis, Penicillium, Bacillus cerevisiae and Bacillus sphaericus, among which Bacillus thuringiensis is the most representative variety.
Bacillus thuringiensis (Bt) is an important insect pathogen that produces spore-forming crystal toxins and has a broad host spectrum of insects. It is a stomach-toxic insecticide. The development of Bacillus thuringiensis preparations in China began in the 1960s. After years of efforts by scientific and technical personnel, there have been breakthroughs in strain selection, fermentation production process, product formulation and application technology, especially in liquid deep fermentation technology, the phage reperfusion rate is from 10 More than % fell below 1%, both of which reached international advanced levels. At present, the research and development of Bacillus thuringiensis is improving the process flow, improving the product quality and expanding the direction of prevention and treatment. At the same time, the research on Bacillus thuringiensis has reached the level of gene, and there are many researches on the coding gene Cry of the insecticidal crystal protein. Breakthrough, the use of genetic engineering technology to construct efficient Bt engineering strains has been reported. China has now passed nearly 70 Bt manufacturers registered by the national pesticide administrative department, with an annual output of more than 30,000 tons. The product dosage forms are mainly liquid agents and emulsions, as well as wettable powders and suspending agents. It is used in more than 20 provinces and cities to control more than 20 kinds of pests on crops such as grain, cotton, fruit, vegetables and forests, with an area of ​​more than 3 million hectares. A large number of experiments and practical applications have shown that Bacillus thuringiensis has different degrees of toxicity to a variety of agricultural pests, including cotton bollworm, tobacco budworm, silver beetle, Spodoptera litura, beet armyworm, small tiger, rice. The leaf roller, corn borer, diamondback moth and tea caterpillar have good effects on the forest pest pine caterpillar. In addition, it can also be used to control mosquito larvae and stored grain moth pests.
2, fungal pesticides
Fungal insecticides are a class of entomopathogenic fungi with a wide range of parasitic spectrum and are a contact microbial insecticide. At present, the main types of research and utilization are: Beauveria bassiana, Metarhizium, Paecilomyces, Chaetomium and Verticillium.
(1) Beauveria bassiana is the fungal insecticide with the longest research time and the largest application area in China. Since the 1960s, domestic research on the use of Beauveria bassiana to control forest pests of pine caterpillars and agricultural pests of corn borer has been developed. By the 1970s, solid phase culture and liquid-solid two-phase production methods and application techniques have been developed and built successively. The factory produces crude products of Beauveria bassiana, and controls pine caterpillars and corn borers in large areas. In the late 1980s, after many years of research and development by scientific and technical personnel from the Chinese Academy of Agricultural Sciences and the Jilin Academy of Agricultural Sciences, a new process for the production of liquid-solid two-phase integrated sporulation of Beauveria bassiana was successfully developed. A breakthrough in the industrial production process of stalagaria. In the late 1990s, Zhejiang University successfully developed a new high-quality production process for the liquid-solid two-phase of Beauveria bassiana. The Chinese Academy of Agricultural Sciences has successfully developed the production process of Beauveria bassiana. Powders, wettable powders, oils, emulsions and microcapsules have been developed on product formulations. At present, the research and development of Beauveria bassiana focuses on industrial production technology, quality standard system, dosage form and industrialization technology. There are only about 10 Beauveria bassiana production plants in China. The scale of the enterprises is small. The production processes used are mostly solid-phase shallow trays and open-screen culture of window screens. The quality of the products produced is unstable, and most of them fail to reach large-scale production. Self-sale, self-use, the annual output is about 200 tons of control powder, the annual control area is 670,000 hectares. There are many hosts for Beauveria bassiana, such as corn borer, pine caterpillar, various scarabs, rice leafhopper, planthopper, mulberry, tea leafhopper, tea caterpillar, soybean borer and aphid, especially for corn borer. And pine caterpillars have been used as a conventional means for years.
(2) Metarhizium anisopliae is a broad-spectrum entomopathogenic bacteria. The area of ​​pest control in foreign countries is more than that of Beauveria bassiana, and the control effect is comparable to Beauveria bassiana.
Second, the principle of application of biological pesticides
1, symptomatic treatment. The specificity and good selectivity of biocides have determined that their insecticidal species and host range are more specific. Insecticides such as Bacillus thuringiensis, insect viruses, etc., which are made of insect-causing microorganisms, can not only prevent lepidopteran pests such as cotton bollworm, cabbage caterpillar, and heartworm. It can also prevent pests such as weevil, Liriomyza sativae. Therefore, when using biocides, they should be selected according to the type of pests.
2. Proper control. The insecticidal mechanism of biological insecticides is different from chemical pesticides, and it usually takes effect through infestation, parasitic accumulation, and effective stomach toxicity. At the time of application, it is necessary to grasp the egg hatching period or the larvae for the younger age. It can not only immerse the insects in the eggs or attach them to the egg shells, but also kills the larvae when they hatch, and can ensure that the pests die after feeding.
3. Scientific application. Biocides are mostly "active", and the application environment and scientific use are the key to their good control. For example, when applying microbial insecticides such as Bacillus thuringiensis and insect viruses, it is generally advisable to apply the evening or cloudy days in warm and humid weather, and it is strictly prohibited to use the fungicides or alkaline pesticides at the same time or in combination. Plant extract pesticides should not be placed for a long time, should be used now, so as not to reduce the efficacy.
Phenolic Rosin Ester (Rosin Modified Phenolic Resin) is made in irregular transparent lump through polycondensation and esterification by Gum Rosin, different phenols, aldehydes,and polyhydric alcohol.
It is soluble in ester, vegetable oil, turpentine,and insoluble in alcohol and water.
This material is used mainly for offset printing for products such as newspapers and magazines. This is a special resin made by modifying a Synthetic Resin, phenol, with a natural resin, rosin. The performance of the resin is determined mainly by the modifier, rosin.
Offset Ink Modified Phenolic Resin
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Dingnan SongYuan Chemical Co.,Ltd , http://www.sy-chinaresin.com