Which of the following is a characteristic of contact herbicides like copper?

Contact herbicides, such as copper-based herbicides, are distinguished by their mode of action, which is to act rapidly on the plant surfaces with which they come into contact. These herbicides typically disrupt cellular function or cause damage upon application, leading to the quick death of the targeted plant tissues.

This immediate effect is crucial when dealing with invasive aquatic plants, as swift results can help mitigate issues like increased nutrient competition and habitat alteration. The rapid action of contact herbicides is beneficial in managing outbreaks effectively, allowing for timely responses to aquatic pest problems.

While other characteristics regarding the broader environmental implications and effectiveness of herbicides are significant, they pertain to systemic herbicides or general herbicide efficacy rather than defining characteristics of contact herbicides specifically. Thus, the characteristic of acting instantly on target plants accurately describes the nature of contact herbicides like copper, highlighting their unique operational mechanism in aquatic pest control.