|Stokes, Courtney -|
|Ditommaso, Antonio -|
|Mohler, Charles -|
Submitted to: Weed Science Society of America Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: February 4, 2013
Publication Date: February 4, 2013
Citation: Stokes, C.A., Ditommaso, A., Mohler, C.L., Milbrath, L.R. 2013. Preliminary studies on seed dispersal of swallow-wort (Vincetoxicum spp.). Weed Science Society of America Meeting Abstracts. http://wssaabstracts.com/public/17/abstract-197.html. Technical Abstract: Vincetoxicum rossicum (pale swallow-wort) and V. nigrum (black swallow-wort) are invasive, perennial vines that have become problematic in natural areas in the northeastern United States and neighboring southeastern Canada. Both species reproduce primarily via wind-dispersed seeds in the form of achenes with a coma. To better characterize seed dispersal of these vining herbaceous species, two studies were initiated. First, settling velocities of seeds of pale swallow-wort and black swallow-wort were measured by dropping individual achene-coma units (pale swallow-wort, n = 106; black swallow-wort, n = 97) down a clear plastic tube measuring 1.22 m in length and 8 cm in diameter. Falling time in seconds was converted to settling velocity in meters per second. The settling velocity of pale swallow-wort seeds was 0.797 m/sec (+/- standard deviation (SD) = 0.219), while black swallow-wort had a slightly slower settling rate of 0.670 m/sec (SD = 0.230). The slower settling rate of black swallow-wort was expected because of the larger coma present in this species. A wind tunnel experiment was also performed to collect additional data that can be used to model swallow-wort seed dispersal. The wind tunnel measured 1.22 by 1.22 m with a 2 m test section. Seeds were released into the wind tunnel from a thin tube. Release heights included 0.6 and 1 m. Wind speeds were 10 and 16 km/h. Seeds were trapped on mesh fabric coated with adhesive spray, placed 0.75 and 1.5 m from the release point. Data are currently being analyzed. Settling rate, release height, wind speed, distance from the release point, and vertical height at the point of collection will be used in conjunction with a linear model to describe seed movement through the wind tunnel.