Title page for ETD etd-10142005-103118
|Type of Document
||Multiple stresses by insect and plant-competition on growth and productivity of Canada thistle
|Kok, Loke T.
|Fell, Richard D.
|Holtzman, Golde I.
|Pfeiffer, Douglas G.
|Pienkowski, Robert L.
|Wolf, Dale D.
- Thistles Growth
- Plant competition
- Canada thistle
- Thistles Insect resistance
|Date of Defense
Canada thistle is an aggressive perennial weed throughout temperate areas
for both the northern and southern hemisphere. As various single tactics have
shown limited success in controlling this weed, I believe that a combination of
different stress factors is necessary for effective sustainable control of Canada
thistle. This study evaluates the competitive abilities of tall fescue grass and
crownvetch in conjunction with a thistle feeding insect for Canada thistle control.
The goal of the study was to determine what levels of the herbivore and plant
competition are needed to suppress Canada thistle.
Field studies were conducted to determine the effects of multiple stresses
caused by defoliation and plant competition on growth and survival of Canada
thistle (Cirsium arvense Scop.). Plant competition was from a cornbination of tall
fescue (Festuca arundinaceae Schreb.) and crownvetch (Coronilla varia L).
Artificial defoliation was used to determine the influence of level and frequency of
defoliation in combination with plant competition on Canada thistle. The effects of
various densities of a defoliator, Cassida rubiginosa (Coleop:Chrysonlelidae), in the
presence and absence of plant competition were also determined. A three-season
study determined the combined effects of C. rubiginosa and plant competitors at various densities on the growth and productivity of Canada thistle plantings of
|| Approximate Download Time
| 28.8 Modem
|| 56K Modem
|| ISDN (64 Kb)
|| ISDN (128 Kb)
|| Higher-speed Access
next to an author's name indicates that all
files or directories associated with their ETD
are accessible from the Virginia Tech campus network only.
If you have questions or technical
problems, please Contact DLA.