(1) Pesticide factors

The composition, physical and chemical properties, dosage form, mode of action, and production quality of pesticides all affect the efficacy of pesticides. Different companies have different production processes and production capacities, and the efficacy of pesticides will also vary. At the same time, it cannot be ruled out that some companies make mistakes in the content and steal the content to affect the efficacy.

In addition, flight prevention aids can also be added when plant protection UAVs are working. High quality flight prevention aids have the characteristics of enhancing adhesion, permeability and expansibility, anti drift, anti evaporation, etc., so as to improve the spraying effect. Of course, besides the medicament itself, the dispensing method is also very important.

(2) Influence of spray quality

The quality of spray directly affects the efficacy. At present, the conventional spray equipment sprays too large droplets, which will bounce when sprayed on the crop surface. About 50% of the liquid drops on the ground, resulting in reduced efficacy. If the median diameter of the droplets of the same amount of liquid medicine is reduced by half, the number of droplets can be increased by 8 times, and the efficacy can also be greatly improved.

(3) The concept of prevention and control needs to be changed

We should change the existing prevention and control concepts of "applying medicine according to the disease, paying more attention to treatment than prevention", adhere to the principle of "prevention first, comprehensive prevention and control", scientifically select pesticide varieties, and suggest that different ingredients of pesticides be used in rotation and mixed with protective agents to delay the occurrence of resistance. On the other hand, it is necessary to enhance the sense of responsibility and enrich the professional knowledge of plant protection, so as to better deal with the complex pests and diseases in the field.

(4) Temperature and humidity affect the efficacy

Temperature: Under high temperature, the effective ingredients of pesticides are easy to photolysis or decompose, the liquid medicine is easy to volatilize or evaporate rapidly, and the stomata of crops may be closed, which is not conducive to the absorption of pesticides by crops. If the temperature is too high or too low, the efficacy will be affected. Generally speaking, the effect of medication is better when the temperature is within the range of 20~30 ℃. If the temperature is higher than 35 ℃, it may have a greater impact on the safety and effectiveness of the operation (of course, the requirements of specific agents on the temperature may be different).

Humidity: The UAV for plant protection uses less water, so the influence of humidity will be greater. In a dry environment, the water consumption needs to be increased accordingly, otherwise, the water consumption can be reduced appropriately.

Wind: It is found that a certain wind speed is more conducive to improving the deposition efficiency of droplets. It is recommended to apply medicine at a wind speed of 1-4m/s, which is conducive to the deposition of droplets on the target. Of course, it is recommended to work in the wind below level 3.

Light: Different types of pesticides may have different sensitivity to light. For example, phoxim, pyrethrin, etc. are easy to photolysis, and are best used for soil treatment, storage pest control, and night spraying; However, herbicides such as photosynthetic inhibitors (such as substituted ureas, mesitylene, etc.) need better lighting conditions. At the same time, pay attention to other weather conditions before and after the injection, such as whether there will be rain, haze, etc.

(5) Crops and pests

The type, growth stage, height and density of crops, as well as the types, living habits and severity of pests and diseases, have an impact on the control effect. This requires adjusting the dosage per mu, operation parameters and medication according to the specific situation, and requires more professional plant protection knowledge.