22 Apr 2021

Comparison of Generic and Proprietary Aquatic Herbicides for Control of Invasive Vegetation : Part 2. Emergent Plants

Abstract: Aquatic herbicides are one of the most effective and widespread ways to manage nuisance vegetation in the US After the active ingredient is selected, often there are numerous proprietary and generic branded products to select from. To date, limited efforts have been made to compare the efficacy of brand name and generic herbicides head to head; therefore, at tot al of 20 mesocosm trials were conducted to evaluate various 2,4 -D, glyphosate, imazapyr, and triclopyr products against alligatorweed (Alternanthera philoxeroides (Mart.) Griseb.), southern cattail (hereafter referred to as cattail, Typha domingensis Pers.), and creeping water primrose (hereafter referred as primrose, Ludwigia peploides (Kunth) P.H. Raven). All active ingredients were applied to foliage at broadcast rates commonly used in applications to public waters. Proprietary and generic 2,4 -D, glyphosate, imazapyr, and triclopyr were efficacious and provided 39 to 99% control of alligatorweed, cattail and primrose in 19 of the 20 trials. There were no significant differences i n product performance except glyphosate vs. alligatorweed (trial 1, Rodeo vs. Roundup Custom) and glyphosate vs. cattail (trial 1, Rodeo vs. Glyphosate 5.4). These results demonstrate under small -scale conditions, the majority of the generic and proprietary herbicides provided similar control of emergent vegetation, regardless of active ingredient.

1 Apr 2020

PUBLICATION NOTICE: Incidence of Zebra Mussel on U.S. Army Corps of Engineers Structures

Abstract: Zebra mussels (Dreissena polymorpha) are invasive/nuisance species first introduced into the Great Lakes region in the late 1980s. Since their introduction efforts have been underway to prevent and/or control their spread. Zebra mussel infestations can occur on submerged critical structure. For the U.S. Army Corps of Engineers (USACE) it is essential that hydraulic infrastructure are effectively and efficiently maintained to ensure proper water control and navigation. A study was conducted to determine the extent of the zebra mussel invasion on USACE districts and the impact zebra mussels have on USACE infrastructure. Consistent with available U.S. Geological Survey (USGS) data, it was found that zebra mussels are present within 24 of the 36 continental United States USACE district boundaries, although San Francisco and Galveston Districts have only isolated populations in non-USACE waters. Albuquerque and Omaha Districts appear to be the two districts most at risk for invasion. While infestations are common, 62% of the districts with USACE infested waters reported no or minimal impacts on the infrastructure or operation/maintenance costs. Those districts with impacts did not normally have cost figures readily available. It was also found that 12 districts have or have had zebra mussel monitoring programs in place.