New Zealand Journal of
Agricultural Research abstracts
Intraspecific plant density
effects in Cirsium arvense
D. M. Leathwick
AgResearch
Private Bag 11 008
Palmerston North, New Zealand
G. W. Bourdôt*
G. A. Hurrell
D. J. Saville
AgResearch
P.O. Box 60
Lincoln, New Zealand
*Author
for correspondence.
graeme.bourdot@agresearch.co.nz
Abstract Cirsium
arvense (Californian thistle)
has been widely studied because of its importance as a weed of
agricultural and natural ecosystems throughout much of the temperate
world. However, its population dynamics has been largely neglected. As
a step toward developing an understanding of the population dynamics of
this weed in pasture, an experiment was conducted during the
1998–99 growing season in Canterbury, New Zealand, in which C.
arvense monocultures were
established at densities of 16, 36, 64, 100, and 144 plants m–2
in sterilised soil in boxes outside. Five destructive harvests were
made from December 1998 to April 1999 and dry weights and numbers of
aerial and subterranean plant parts were measured. The growth in size
of individual C.
arvense
plants was retarded as plant density was increased, primarily by a
reduction in the formation of new root resulting in reduced recruitment
of new aerial shoots. By contrast, the density of the buds on these
roots, and their germination rates, were independent of plant density.
Keywords buds;
Californian thistle; Canada thistle; creeping thistle; demography;
growth analysis; roots
A05035; Received 2 August 2005;
accepted 1 December 2005; Online publication date 28 February 2006
New Zealand Journal of
Agricultural Research, 2006, Vol. 49:
13–24
0028–8233/06/4901–0013 © The Royal Society of New
Zealand 2006
PDF file of entire paper: Print-quality
(365K) | screen-quality
(482K)
This year's abstracts
|
Journal
home page |
All abstracts
|
Publishing
home page
