Response of swallow-wort to herbicides

Abstract

The exotic plant, swallow-wort, a twining perennial of the Milkweed family, has become increasingly invasive in natural areas, successional old fields, and tree plantations on calcareous soils of the lower Great Lakes basin. Because mechanical control strategies are inadequate, swallow-wort's response in natural areas to foliar spray and cut-stem applications of glyphosate and triclopyr was evaluated. Foliar spray applications of glyphosate (3.1 and 7.8 kg ae ha–1) and triclopyr (1.9 kg ae ha–1) were more effective than cut-stem applications of the herbicides (3.1 kg ae ha–1 glyphosate, 1.4 kg ae ha–1 triclopyr). There were no statistical differences in effect among the foliar spray applications. Response to cut-stem application of glyphosate (3.1 and 6.2 kg ha–1) and triclopyr (1.4, 2.8, and 5.6 kg ha–1) in the following year indicated glyphosate to be more effective than triclopyr at all concentrations tested. To effect long-lasting control, all treatments require additional herbicide application.

The Biology of Invasive Alien Plants in Canada. 2. Cynanchum rossicum (Kleopow) Borhidi [= Vincetoxicum rossicum (Kleopow) Barbar.] and Cynanchum louiseae (L.) Kartesz & Gandhi [= Vincetoxicum nigrum (L.) Moench]

“…Single applications of glyphosate did not provide satisfactory control. Lawlor and Raynal (2002) compared the effectiveness of two non-selective herbicides, glyphosate and triclopyr, to suppress C. rossicum populations in central New York State, when applied either as foliar sprays or to cut stems. Foliarspray applications were more effective than cut-stem applications in reducing cover and biomass.…”

Response of Pale Swallow-wort, <em>Vincetoxicum rossicum</em>, following Aboveground Tissue Loss: Implications for the Timing of Mechanical Control

“…Herbicides such as glyphosate are moderately effective; however, several applications are needed (Christensen 1998;Lawlor and Raynal 2002). A growing number of communities are banning herbicides due to their toxicity to humans and non-target organisms (DiTomaso 1997); in these places, manual means of controlling Swallow-wort are necessary.…”

A Review of the Biology and Ecology of Three Invasive Perennials in New York State: Japanese Knotweed (Polygonum cuspidatum), Mugwort (Artemisia vulgaris) and Pale Swallow-wort (Vincetoxicum rossicum)

“…There were no significant differences in reduction of measured plant parameters among the foliar-spray treatments and effective long-term control using either of these herbicides at recommended field rates required repeated applications. Cut-stem applications of glyphosate (4.1 and 8.3 kg ai ha )1 ) were found to be significantly more effective than similar treatments with triclopyr (1.9, 3.9 and 7.8 kg ai ha )1 ) at all concentrations tested (Lawlor and Raynal, 2002).…”

“…Lawlor and Raynal (2002) compared the effectiveness of two systemic herbicides, glyphosate and triclopyr, to control populations of pale swallow-wort in central NY as either foliar sprays or when applied to cut stems. Foliar-spray applications were more effective than cut-stem applications in reducing cover and biomass.…”