Six precautions to note when using bacterial biological insecticides
Biological pesticide: BT, Chinese name Bacillus thuringiensis, is a bacterial insecticide. This variety has been fully used in the main vegetable-growing areas of our country and has achieved good economic benefits. However, there are currently many BT manufacturers with varying quality, so when using it you must choose a variety of good quality. Note: BT is effective when the temperature is slightly higher...
Bacterial biological insecticides have the advantages of a high insecticidal rate, no environmental pollution, safety to natural enemies, harmlessness to humans and livestock, and not inducing pest resistance. They are a new type of protective agent currently promoted for key use in pollution-free cultivation. Because their control effect mainly depends on the bacterial activity in the agent, the following six points should be noted when using them:1. Do not use inferior agents
They should be purchased from regular manufacturers and agent sales outlets to prevent counterfeiting and shoddy goods, and attention should be paid to the agent's production date, service life, and reasonable storage to prevent failure from expiration. In addition, normal agent products generally contain a certain amount of bacteria; when the lid is opened there should be no bad odor, and sometimes there may even be a fragrant smell (given off by the culture medium), while expired or fake products often produce an abnormal odor or have no smell.
2. Do not use at low temperatures
The active ingredients of bacterial biological insecticides are protein crystals and living spores. Under low-temperature conditions, the spores reproduce slowly in the pest body, and the protein crystals do not easily take effect. Ambient temperatures of generally 10-35°C are suitable; if too low, it will affect the insects' food intake and the control effect will be poorer.
3. Do not subject to heavy rain washing
If moderate to heavy rain occurs shortly after spraying a bacterial biological insecticide, it will wash away the bacterial solution sprayed on the crop stems and leaves and reduce the efficacy. However, if light rain falls 5 hours after application, it will not only fail to reduce the control effect but may even have a synergistic effect.
4. Do not mix with fungicides
When applying bacterial biological insecticides, never mix them with fungicides (such as carbendazim, thiophanate, etc.), otherwise it can easily cause a serious reduction in the number of bacteria in the agent, thereby affecting the insecticidal effect. Therefore, even a sprayer that has been used for fungicides must be rinsed clean before being filled with bacterial biological insecticide.
5. Avoid dry environments
The bacterial spores in bacterial biological insecticides prefer humid environments, so when using them, the higher the field humidity, the higher the efficacy; especially when spraying powdered biological pesticide formulations, even more attention should be paid to field humidity. Generally, bacterial powder formulations are sprayed in the early morning and evening when there is dew.
6. Avoid strong light
Ultraviolet rays in sunlight have a killing effect on spores; if the light is strong, ultraviolet rays will kill the bacteria. Therefore, bacterial biological insecticides should be sprayed on cloudy days or in fields with weak light. Generally, application is carried out before 10 a.m. on sunny days or in the evening.