1. Use of agrochemicals in windy days: General powder agrochemicals and spray agrochemicals will be affected by strong winds, easy to be blown away, thus reducing the efficacy of agrochemicals and failing to achieve the effect. Moreover, agrochemicals spread by wind can easily cause environmental pollution. Thus the wind speed should not exceed 1 m/s when dusting in strong wind. For low volume spraying, wind speed should not exceed 5 m/s; for ultra-low volume spraying, wind speed should not exceed 1-3 m/s.
2. Use of agrochemicals in rainy days: Agrochemicals are easily washed away by rain or diluted by rain, which cannot achieve the expected effect. The inflow of agrochemicals into soil may also cause environmental pollution.
3. Spraying agrochemicals at high temperature: Agrochemicals are easy to volatilize and decompose, affecting the effect and even causing poisoning of applicators. Generally, the suitablespraying temperature is 20-30℃.
4. Dilution of agrochemicals with well water: Well water contains a large amount of calcium and magnesium substances. Dilution of agrochemicals with well water will destroy the emulsification and suspension performance of the agrochemicals, reduce or even completely destroy the drug effect, not only affecting the prevention and control effect, but also easily causing drug damage.
5. Spraying with wettable powder agrochemicals: Wettable powder is a powder made by adding a certain amount of wetting agent and filling material into the original medicine and mechanically grinding or airflow crushing it. Compared with common powder, wettable powder has high content of active ingredients and poor fluidity. Therefore, it can only be used as suspension after dissolving water, and is not allowed to be sprayed directly as powder.
6. Submerged spray of granular agrochemicals: The specifications and composition of granular pesticides are mostly developed and produced according to the biological characteristics of the controlled and protected objects and the environmental conditions of the application site, thus having strong specificity, special effect and delivery target. At present, it is mainly used for ground and underground application to control weeds or pests, and soaking spraying is not allowed. In addition, most of the raw medicines for producing granules are highly toxic agrochemicals, and the toxicity is reduced after granulation treatment, so that the safety in use can be increased; soaking spraying will make its toxicity return, and it is easy to cause poisoning of applicators in using.
7. Use highly toxic agrochemicals for ultra-low volume spraying: As the concentration of ultra-low volume spraying is higher than that of conventional spraying, it is only limited to spraying agrochemicals with lower toxicity, such as pyrethroid pesticides. In addition, the application personnel must always walk between the lines without drugs in the upper stage. It is forbidden to use highly toxic agrochemicals for ultra-low volume spraying, so as not to cause productive poisoning.