What are the disadvantages of biological pesticides?

With the rapid development of pesticide industry, the shortcomings of chemical pesticides are becoming more and more prominent. Compared with chemical pesticides, biological pesticides have obvious advantages in some aspects and are sought after by people. What are the disadvantages of biological pesticides? Biological pesticides are generally effective only for one kind of pests, but not for other pests. It requires high temperature and humidity, and the suitable temperature for microbial pesticides is 15-30℃. It is sensitive to ultraviolet rays and has a fatal killing effect on microbial pesticides. However, the drug effect is slow, and the pests and diseases will not take effect immediately after use, and the application time should be 2-3 days earlier than that of chemical pesticides.

Chemical pesticides are mostly treated with chemical synthetic agents and harmful chemical additives, while microbial pesticides are treated with biological pesticides. In the process of microbial pesticide treatment, pathogenic bacteria are in a state of inhibition, while microbial pesticides are in an active state, which has a great influence on the control effect of biological pesticides. In order to avoid the toxicity, residue, harmful pollution and safe use of microbial pesticides, agricultural microbial preparations with safety, high efficiency, low toxicity, low residue and no secondary pollution should be selected as far as possible.

In the process of preparation, it should be carried out in strict accordance with the standard requirements, and at the same time, bactericide, disinfectant and drier should be added to avoid phytotoxicity and improve the efficacy of the preparation as much as possible. Microbial pesticides can be used in various crops, mainly crop diseases and weeds, which are generally harmful to crops, with good effect and strong safety, and can be used to prevent and control crops that have been stubbled for more than one year or that are geographically important. These pesticides are characterized by non-toxic and harmless to a variety of organisms and strong duration, but they are not suitable for diseases and insect pests with obvious symptoms because of their large dosage.

Therefore, when using microbial pesticides to control pests and diseases, we should pay attention to the following problems: ① the dosage should be reduced as much as possible, and it is easy to produce too fast efficacy or toxicity if the dosage is too large; Excessive dosage is easy to cause phytotoxicity; Too little dosage will reduce the efficacy. The dosage and crop types should be strictly controlled, and appropriate pesticide application equipment should be used; (2) When applying pesticides, we should reduce the application times and times as much as possible to avoid the occurrence of phytotoxicity.