Why not use pesticides in hot weather?

Generally speaking, high temperature will promote the decomposition of pesticides, shorten the duration of pesticides, reduce the control effect and increase phytotoxicity. The main reasons are: first, the use of pesticides at high temperature will accelerate the chemical decomposition of pesticides; Second, high-temperature ultraviolet rays are also stronger, which will also accelerate the decomposition of drugs; Third, high temperature can promote the volatilization of effective components of drugs; Fourthly, in the high temperature weather, the chemical activity of chemicals is relatively strong, and the toxicity of pesticides is also relatively large. In hot weather, the metabolism of trees is relatively strong, and the stomata on the leaves are large and open. When spraying, chemicals can easily enter the body, which is prone to phytotoxicity. For example, lime-sulfur mixture, emulsifiable concentrate and some herbicides are all used at high temperature. Therefore, in hot weather, if it is really necessary to use pesticides, the concentration of herbicides should be lower, and try not to use pesticides at hot noon to avoid phytotoxicity and poisoning accidents of users.