Torpedograss control via submersed applications of systemic and contact herbicidesin mesocosms

摘要

Torpedograss (Panicum repens L.) is an invasive plant that is found in terrestrial and aquatic settings (Sutton 1996, Smith et al. 2004, Toth 2007). In aquatic systems, torpedograss impedes boat access and drainage flow in waterbodies (Smith et al. 1993, 2004). In the southeastern United States, torpedograss is a major problem in riparian areas and along drainage canals. Torpedograss is capable of aggressive range expansion in shallow water bodies when left unmanaged, and if left uncontrolled, plantscan shade out native submersed, floating, and emergent plant species that provide beneficial habitat for native fauna (Hanlon and Brady 2005, Toth 2007), thereby causing ecological problems such as lowered dissolved oxygen in the water column and lowerbiodiversity (Hanlon and Langeland 2000).The native range of torpedograss is uncertain; the literature suggests that this species may be native to the Americas (Guglieri et al. 2004, Liu et al. 2006), the Mediterranean region, and Africa (Waterhouse 1994), or Australia (Hoyer et al. 1996). In 1896, the earliest known specimen in the United States was collected near Mobile, AL (Tarver 1979); since that time, torpedograss has spread throughout the southeastern United States from North Carolina to Texas. Additionally, range expansion has occurredwith introductions into California and Hawaii (U.S. Department of Agriculture Natural Resources Conservation Service 2018). Torpedograss can reproduce sexually through seed production (Moreira 1978) and asexually through fragmentation; however, populations in the United States have only been documented to reproduce vegetatively (Wilcut et al. 1988).