Our team is beginning the fourth year of Eurasian Milfoil control efforts on the Pend Oreille Lake and River system in north Idaho. Control efforts there have reduced this infestation from a coverage range in excess of 6,000 acres to near 1,000 that will be targeted this summer.
Much of the work performed in 2006 has resulted in complete control four years later in the summer of 2009. Areas treated with Sonar herbicide such as Perch and Fry Creek have remained milfoil free since. Another example is Riley Creek Bay. This site was choked with this weed in 2006 and was targeted with Renovate, a systemic selective aquatic herbicide.
Four years later, this bay remains milfoil free and is supporting a very diverse community of native aquatic plant life. This one treatment has provided four summers of Eurasian Milfoil control from one application providing a significant benefit of that application.
For more information go to the project blog article at http://pomilfoil.wordpress.com/2009/07/19/riley-creek-four-years-after-renovate-herbicide-treatment/