Technical points for the use of biological pesticides

The production of pollution-free agricultural products has become the direction of agricultural production development. In the production process of agricultural products, the use of biological pesticides for pests and diseases has attracted worldwide attention. At present, biological pesticides have been widely used in food, vegetables, fruit trees and flowers. However, the use of bio-pesticides is affected by many factors. There are a series of problems in practical applications. The scientific use of biological pesticides should maximize the use of favorable factors to overcome and avoid adverse factors. Pay attention to the following points in use.

First, according to different control objects to choose different pesticide varieties The current production of biological pesticides are pesticides, fungicides and antibiotics, fungicides and other types of antibiotics made from microbial products. In the practical application of biological pesticides. Many people still don't fully understand the nature of biological pesticides. They mistakenly believe that biological insecticides and fungicides can prevent and cure all diseases and insect pests, and they are not widely used. This will not only prevent the effects, but also delay the prevention and treatment. period. Biopharmaceutical selectivity is very strong. For example, Bacillus thuringiensis (Bt) is effective for controlling lepidopteran larvae, but it is not pathogenic to the leafhopper of the same wing, and the control effects of different strains of Bacillus thuringiensis on several important pests are also There are differences. In addition, different types of biological pesticides should be used according to the feeding characteristics of pests. For example, Bt has a good effect on lepidopteran pests. After spraying, it will be distributed on the surface of plants, causing pests to feed or bacteria to die, but pests that suck the juice. (such as mites, mites) is not effective, and avermectin has a very good effect on mites. Therefore, suitable biopesticide varieties should be selected in a targeted manner for different types of pests.

Second, according to the control object and conditions to select the appropriate biological pesticides, the biological pesticides are often closely related to the dosage form and use technology. When using, according to the control object, meteorological conditions and use time, the correct dosage form should be selected correctly to achieve the best. Control effect. For example, the powder can be dispersed in a wide range by means of air buoyancy and wind, so that it has greater contact with pests; for pests with a large amount of edible leaves, such as cabbage caterpillar, the method of spraying wettable powder with water can be used as a suspension. Ok, and the effect of using the dusting method is poor. Capsules not only have a long release effect. And it can protect the pathogens from environmental factors. Can be used in greenhouses.

Third, according to different control objects to determine the appropriate control period pests are the object of biological pesticides, for different types and characteristics of pests, the use of biological pesticides are also different. Pests have several different developmental stages in their lifetime, and their resistance to biocides is different at each stage of development. Therefore, understanding the developmental stage of pests is very necessary for prevention and control. For example, Cabbage caterpillars can be divided into four stages: egg, larva, pupa and adult. The egg stage is protected by egg shells, and the larvae are protected by scorpion. Older larvae have thicker wax layer protection. flight. Therefore, only choose the young larvae to make medicine. In order to give full play to the effects of biological pesticides.

4. Selecting the best use time according to local climatic conditions The use effect of biological pesticides is greatly affected by environmental factors. In fact, it takes a certain amount of time for biological pesticides to be taken from plants to pests to feed or catch bacteria. It takes a process to feed from pests to death. It is susceptible to the environment during this period. The most influential factors are temperature, humidity, light and wind. Temperature not only acts on biological insecticide spores, but also on the pest itself, thus affecting the pathogenicity and toxicity of pathogenic microorganisms: humidity has a direct relationship with the propagation and spread of biocide spores, humidity, microbial spore reproduction and Rapid diffusion, easy to infect and kill pests; ultraviolet rays in the sun have a lethal killing effect on spores, so should avoid glare when using, should be before 8:00 on sunny days, after 16:00 or in no The cloudy effect of rain is better; the wind plays an important role in the drift and diffusion of powder bio-pesticides. The use of dust bio-pesticides is the best in the breeze.

5. Choosing the right spray equipment In practical applications, most plant protection equipments are currently used at low efficiency. Usually, crops are sprayed directly from top to bottom, so that a large amount of pesticides are concentrated on the leaves above the crops. There are fewer pesticides attached, and the loss of falling on the surface of the soil is more. If the fog is large, the loss is even greater. Due to the high production cost of biological pesticides, it is necessary to select plant protection equipment with high spraying efficiency, good atomization degree and pesticide saving. Such as mist sprayer, mist sprayer, etc.

Sixth, according to different regions to create appropriate conditions, the use of biological pesticides in different regions is not the same. China has a vast territory, and the regional differences are large. The south is humid and rainy. The north and west are dry and drier.

Biological pesticides can only be used to their fullest extent when they meet the best conditions for their lives. On the one hand, it is necessary to increase the amount of sprayed medicinal water in arid areas, resulting in a high-humidity environment, which is easy to survive and multiply microbial spores; on the other hand, it can add some specific high-molecular substances and substances that increase the viscosity of the solution, such as Starch, animal bone glue, grass ash leaching solution, etc., can reduce evaporation, avoid rapid drying, and improve utilization efficiency. In addition, according to the migratory characteristics of pests. It is also possible to use biopesticide in combination with highly effective and low-toxic chemical pesticides. Chemical pesticides can reduce the resistance of pests. It creates conditions for the invasion of pathogenic microorganisms, and at the same time, when the pests are infested by pathogenic microorganisms, the resistance to chemical pesticides is also reduced, and the two complement each other, thereby achieving the effect of increasing the efficacy.