Small-scale Primary Screening Method to Predict Impacts of the Herbicide Flumioxazin on Native and Invasive Emergent Plants.

摘要

The purpose of this work was to develop and utilize a rapid, small- scale primary screening method to evaluate the activity of a recently registered aquatic herbicide, flumioxazin, against 23 native emergent plant species and five invasive emergent species. In evaluating potential use patterns of new aquatic herbicides, it is important to determine concentrations that impact target as well as non-target vegetation. The recently registered aquatic herbicide flumioxazin is efficacious against the floating weeds water lettuce (Pistia stratiotes L.) and giant salvinia (Salvinia molesta Mitchell) (Richardson et al. 2008) as well as the submersed species hydrilla (Hydrilla verticillata (L.f.) Royle) (Mudge and Haller 2006) and Eurasian watermilfoil (Myriophyllum spicatum L.) (Getsinger et al. 2011). These species are often found in close proximity to or intermixed with native emergent vegetation and information on the impact of flumioxazin to most emergent plant species is limited. Information regarding the selectivity of flumioxazin (and other aquatic herbicides) will help resource managers decide which herbicides, use rates, and timing of application are most appropriate to reduce injury to the native emergent species present. This work has become increasingly relevant as research conducted last year demonstrated a potential selective use pattern for flumioxazin in areas where water lettuce is intermixed with emergent species (Netherland 2011). The endangered snail kite (Rosthramus sociabilis) is utilizing habitats in areas of large-scale floating plant control operations. Current operational use of the broad-spectrum herbicide diquat, while highly effective at controlling water lettuce, generally results in significant visual injury symptoms on numerous emergent plant species.