Efficacy of Postemergence Herbicides for Control of Small-Leaf Spiderwort (Tradescantia fluminensis) in Florida

Abstract

Tradescantia fluminensis (small-leaf spiderwort; SLSW) is a fast-growing herbaceous groundcover and one of the most problematic invasive plants in Florida. The objective of this research was to determine the efficacy of selected postemergence herbicides for SLSW control in greenhouse and field experiments in Florida. An additional objective was to determine if pre-cutting plants would increase herbicidal efficacy. In greenhouse experiments, cutting mature SLSW plants increased the control of most herbicides evaluated. Overall, triclopyr ester provided the highest level of control along with triclopyr amine, triclopyr choline, and glufosinate, all of which were similar. Few differences were observed between 2,4-D, aminopyralid, metsulfuron-methyl, sulfentrazone, and glyphosate and all provided ≤66% control as evidenced by shoot weight reduction. In field experiments, pre-cutting SLSW had no effect on herbicide efficacy. Triclopyr was again generally the most efficacious treatment, outperforming glyphosate, aminopyralid, glufosinate, and fluroxypyr on most evaluation dates, especially as trials progressed past 5 mo. Overall, data suggest that triclopyr would be the most effective option for SLSW management. However, as efficacy was noted with fluroxypyr, glyphosate, and glufosinate depending upon location, other options exist. Further research is needed to determine reapplication intervals and effects on nontarget native plants in order to develop comprehensive management plans.