What is the primary characteristic of contact herbicides?

Contact herbicides are designed to act directly on the plant tissue they come in contact with, which means their primary characteristic is that they only affect the parts of the plant that the herbicide reaches. This localized action allows for the plant to potentially regrow from the roots or other unaffected parts, as the roots themselves are not directly harmed as they remain undamaged below the surface.

This is particularly important in aquatic environments where some plants may play vital roles in the ecosystem, allowing for management of unwanted species while minimizing long-term impacts on the overall plant community. The ability for tissues to recover if the roots remain intact is a distinguishing feature of contact herbicides, setting them apart from systemic herbicides, which are absorbed and can affect the whole plant.