What should I pay attention to when spraying pesticides in low temperature weather?

1, pesticides should be selected reasonably when spraying pesticides at low temperature. Some pesticides (such as dimethoate). ) is greatly affected by temperature, and its efficacy is obviously weakened with the decrease of temperature, while some pesticides (such as omethoate, etc. ) is less affected by temperature, and can play its normal insecticidal role even at low temperature. Similar to omethoate, pyrethroids also have killing effect, but the toxicity of this insecticide is higher at low temperature than at high temperature. Therefore, in order to prevent and control crop diseases and insect pests in winter and spring, we should pay attention to selecting pesticides that are less affected by temperature.

2. Appropriate increase of pesticide dosage in low temperature season. Under the guidance of professionals, the dosage should be appropriately increased to improve the concentration of liquid medicine, but it should not exceed the "safe high concentration" (that is, the maximum allowable dose without drug harm).

3. When the application temperature is high in sunny days and high temperatures, the range of activities and respiratory intensity of pests will increase, and the food intake will also increase. At this time, the application of pesticides will help improve the control effect.

4. Improve the application methods for preventing and controlling greenhouse crop diseases and insect pests in winter and spring, and try to use smoke method or dust method; If spraying method is adopted, it is necessary to appropriately reduce the number of prevention and control times and spray the amount of liquid medicine to prevent humidity in the shed.

5. Appropriately extend the safety interval. In the low temperature season, the degradation speed of pesticides is slow and the residue time in crops is relatively long. Therefore, it is necessary to appropriately extend the number of days between the last application of pesticides and crop harvest (that is, the safe interval) to ensure food safety.