After an agreement between the Secretary and the county is executed, the Secretary and the county may conduct surveys to determine the location and amount of infestation of a noxious weed or other plant species within the county. Both parties may provide technical assistance to landowners in a cooperative control or eradication program, and may effect a program of mowing, spraying, or other control or eradication practices on any road right–of–way, drainage ditch bank, park, playground, and any other public or private land. The agreement between the Secretary and county may be terminated by either party on 30 days’ written notice.