What is meant by "residual activity" of a pesticide?

The term "residual activity" refers to the duration of time that a pesticide remains effective after it has been applied. This means that once the pesticide has been introduced into the environment, it continues to exert its effects on pests for a specific period. Understanding residual activity is crucial for users because it influences how often applications are needed to maintain pest control and helps in planning application schedules based on the pesticide's effectiveness over time.

In contrast, the absorption of the pesticide by plants relates to how well a plant can take in the pesticide, which may impact its efficacy but does not define residual activity. The frequency of application pertains to how often a product must be reapplied to effectively manage pests, again not defining its residual characteristics. Lastly, toxicity level refers to how harmful a pesticide can be to humans, animals, or plants, which is distinct from the effectiveness duration of the pesticide post-application. Understanding these distinctions helps in better managing and applying pesticides responsibly in various settings.