Use of herbicides in areas of high water exchange:Practical considerations

摘要

There are a number of fundamental elements that must be considered when conducting a herbicide application to control submersed plants in large lakes, reservoirs, streams, and rivers. These fundamentals include general weed control principles such asproper identification of the target plant, selection of an herbicide that is effective against that target plant, and water quality. Other principles are crucial to applications that treat only a portion of a water body—rather than the entire water body—especially where water movement or flow might occur in the treatment area. In these cases, the aqueous herbicide concentration and exposure time (CET) relationships required for desired control of the target plant, size, and location of the treated site and, most importantly, site-specific bulk water exchange processes are essential components for treatment success. In this paper, we will review and discuss how the principles of CET relationships and water exchange processes are linked to the success,or failure, of submersed applications in the field, whether for research and demonstration purposes, or for operational activities. Although the principles of CET relationships and water exchange exist in water conveyance systems, such as irrigation and drainage canals, we will limit our discussion to partial treatments in surface water bodies for controlling submersed plants.