Comparison of Imazapyr and Imazamox for Control of Parrotfeather (Myriophyllum aquaticum (Veil.) Verde.)

摘要

Parrotfeather (Myriophyllum aquaticum (Veil. Verde) is an invasive aquatic plant to the United States that is native to South America. Myriophyllum aquaticum is described as "stout, stems moderately elongate, partially submersed but with portions of leafy branches emersed (Godfrey and Wooten 1981). Emergent leaves are whorled, stiff, usually with 20 or more linear filiform divisions, appearing feather-like and grayish green. Submersed shoots are comprised of whorls of four to six filamentous, pectinate, red or orange, leaves arising from each node. Flowers are all pistillate, borne in the axils of unreduced leaves (Godfrey and Wooten 1981). Myriophyllum aquaticum is dioecious, however only pistillate plants are found outside of its native range (Sutton 1985). In fact, staminate plants are rare even in native populations of South America (Orchard 1981). For this reason, seed production is not known to occur and reproduction is exclusively vegetative through fragmentation of emergent shoots, submersed shoots, and stolons (Aik-en 1981, Orchard 1981). Additionally, M. aquaticum lacks structures for storage, dispersal, and perennation (e.g., tubers, turions, and winter buds) and therefore stolons are believed to serve all these functions (Sytsma and Anderson 1993).