Selective Control of Purple Loosestrife with Triclopyr

摘要

Purple loosestrife (Lythrum salicaria), an emergent, herbaceous perennial ofEurasian origin, was first reported along the northeastern coast of North America in the early 1800s. Since then, this highly invasive wetland plant has spread to 40 States and Canada, with serious infestations extending to the Pacific Northwest and populations reported as far south as Huntsville, AL, and Beaumont, TX. Once established in a wetland, purple loosestrife displaces native vegetation through rapid growth and prolific seed production. A single mature plant can produce more than 2.5 million seeds per growing season (Thompson, Stucky, and Thompson 1987). This large seedbank is highly viable with a germination rate of >95 percent for fresh seed and 80 percent after 2 to 3 years' submergence (Shamsi and Whitehead 1974). The end result is a monotypic stand of purple loosestrife that not only dramatically decreases the vegetative diversity of the wetland but also provides little food or habitat for associated wildlife (Smith 1964; Rawinski and Malecki 1984; Thompson, Stucky, Thompson 1987). Several states (California, Idaho, Washington, Minnesota, Ohio, and Wisconsin) and one Canadian Province (Manitoba) currently have legislation to combat the spread of this exotic plant pest. pg10. JMD.