What are the precautions for using bacterial biological insecticides?
To use pesticides to control crop pests and achieve the best insecticidal effect, while selecting the right pesticide and applying it at the right time, you must, based on the three factors that affect efficacy, pay attention to solving the two easily overlooked problems of timely application and delivering the pesticide to the target. 1. The three factors affecting efficacy. 1. Climate. Application...
Bacterial biological insecticides have advantages such as 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 pesticide currently promoted for key use in pollution-free cultivation. Because their control effect mainly depends on the bacterial activity in the pesticide, the following six points should be noted during use:1. Avoid using inferior pesticides
They should be purchased from regular manufacturers and pesticide sales outlets to prevent counterfeiting and shoddy products, and attention should be paid to the pesticide's production date, period of use, and reasonable storage to prevent expiration and loss of efficacy. In addition, normal pesticide products generally contain a certain amount of bacteria; when the lid is opened there should be no foul odor, and sometimes there may be a fragrant smell (given off by the culture medium), while expired or fake pesticide products often produce an unusual odor or have no smell.
2. Avoid 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's 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' feeding amount, and the control effect will be somewhat poorer.
3. Avoid heavy rain washing
If moderate to heavy rain occurs shortly after spraying a bacterial biological insecticide, it will wash away the bacterial liquid sprayed on the crop stems and leaves and reduce efficacy. However, if light rain falls 5 hours after application, it will not reduce the control effect but instead have a synergistic effect.
4. Avoid mixing with fungicides
When applying bacterial biological insecticides, never mix them with fungicides (such as carbendazim, thiophanate-methyl, etc.), otherwise it will easily lead to a serious reduction in the number of bacteria in the pesticide, 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 insecticides.
5. Avoid dry environments
The bacterial spores in bacterial biological insecticides prefer humid environments, so the greater the field humidity during use, the higher the efficacy. This is especially true when spraying powdered biological pesticide formulations, and field humidity should be paid even more attention. 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, spraying bacterial biological insecticides should be carried out on cloudy days or in weak light. Generally, application is carried out before 10 a.m. on sunny days or in the evening.