Submitted to: Weed Science Society of America Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 11/15/2008
Publication Date: 2/9/2009
Citation: Averill, K.M., Ditommaso, A., Mohler, C.L., Milbrath, L.R. 2009. Pale Swallow-wort Establishment and Survival in Four Disturbance Regimens in New York State. Weed Science Society of America Meeting Abstracts. no. 270. Lawrence, KS:Weed Science Society of America. (http://wssa.net/Meetings/WSSAAbstracts/abstractsearch.php). Interpretive Summary:
Technical Abstract: Pale swallowwort (Vincetoxicum rossicum) is a nonnative, perennial, herbaceous vine in the Apocynaceae that is invading natural areas in the northeastern United States and southeastern Canada. The species forms dense stands across a wide range of moisture regimes in full sun or forest understories. The dense colonies outcompete resident vegetation and reduce vertebrate and invertebrate biodiversity. A classical biological control program was initiated by the USDA-ARS in 2004 with the goal of providing sustainable and economical long-term suppression of this aggressive species. The success of this biological control effort depends on the availability of plant demographic data that can be modeled to determine which swallowwort life stage(s) may be most susceptible to control efforts. Since little is known about the establishment phase of pale swallowwort’s life cycle, we conducted a field experiment in central New York State to determine establishment and survival during the first two years after sowing. In November 2006, we planted pale swallowwort seeds in two old fields subjected to four disturbance regimens. The treatments were established in a randomized complete block design with 8 replications at each site: (1) one application of isopropylamine salt of glyphosate (3.0 kg ae/ha) plus diglycolamine salt of dicamba (1.9 kg ae/ha), followed by rotary tillage to 15 cm depth in 2006, (2) one application of glyphosate plus dicamba in 2006, (3) mowing to approximately 20 cm once per year, and (4) an undisturbed control. We hypothesized that establishment and survival would be greater in treatments with greater disturbance. At the Mt. Pleasant site, which is at a greater elevation and is better drained than the Hanshaw site, overall pale swallowwort establishment (seedling emergence as of August 2007) was 15 +/- 1% and did not differ between treatments. At the Hanshaw site, establishment varied by treatment; mowed and control plots had greater swallowwort establishment (10 +/- 2%) than herbicide + tillage and herbicide plots (1.6 +/- 0.5%). Of those seedlings that emerged in 2007, survival to August 2008 (84 +/- 4%) was not affected by treatment at Mt. Pleasant. At Hanshaw, survival was greater in mowed, control, and herbicide plots (73 +/- 6%) than in herbicide + tillage plots (17 +/- 17%). Only at the Mt. Pleasant site in the herbicide + tillage (3 +/- 3%) and herbicide plots (4 +/- 3%) did swallowwort plants produce mature follicles in 2008. These results indicate that pale swallowwort establishment and survival is successful across a range of disturbance regimens and that soil drainage may contribute to the observed variations in pale swallowwort establishment and survival.