Low capsule set is a major factor limiting the productivity of Eucalyptus globulus seed orchards. This study tested the effect of flower density, as well as two common irrigation techniques on capsule and seed set. Ramets with high flower density had significantly lower capsule set (69.7%) than those with low flower density (81.7%). In a regulated deficit irrigation trial, the non-irrigated ramets set a higher proportion of capsules (63.6%) than the ramets that received conventional irrigation (CI) (51.4%). In a partial root zone drying (PRD) trial, capsule set was highest in the absence of irrigation (74.7%) followed by the PRD treatment (67.8%) and then CI (53.7%). The CI treatment tended to produce the highest number of seed per capsule. Increased water availability resulted in increased vegetative growth, which was associated with higher levels of abortion in developing capsules but those surviving tended to have higher seed set. It is argued that the observed effects of irrigation and flower density can be explained by resource competition between vegetative and reproductive growth as well as competition among reproductive structures themselves. © Springer Science+Business Media B.V. 2009.

Item Type:	Refereed Article
Research Division:	Biological Sciences
Research Group:	Plant biology
Research Field:	Plant developmental and reproductive biology
Objective Division:	Plant Production and Plant Primary Products
Objective Group:	Forestry
Objective Field:	Hardwood plantations
UTAS Author:	Suitor, S (Dr Shaun Suitor)
UTAS Author:	Potts, BM (Professor Brad Potts)
UTAS Author:	Brown, PH (Professor Phil Brown)
UTAS Author:	Gracie, AJ (Professor Alistair Gracie)
UTAS Author:	Rix, KD (Dr Kieren Rix)
UTAS Author:	Gore, PL (Mr Peter Gore)
ID Code:	54525
Year Published:	2010
Web of Science® Times Cited:	3
Deposited By:	Agricultural Science
Deposited On:	2009-02-24
Last Modified:	2011-04-13
Downloads:	0