Native Plants Journal - Article

Initial mortality and root and shoot growth of valley oak seedlings outplanted as seeds and as container stock under different irrigation regimes

Abstract:

Direct seeding of valley oak (Quercus lobata Nee [Fagaceae]),
commonly used in restoration in the Central Valley of California,
may be preferable to using container stock, at least in
nonirrigated sites and where acorn predation can be controlled.
In a stratified random experiment we tested initial
growth and survival of oaks either: 1) outplanted as acorns; 2)
outplanted as 3-mo-old container seedlings; 3) outplanted as
3-mo-old container seedlings that had been transplanted into
larger containers 6 wk before outplanting; and 4) outplanted
as 1-y-old container seedlings (commercial stock).We subjected
each of these to 3 different irrigation regimes: 1) none;
2) drip; or 3) overhead. Half of the irrigated oaks were
watered for 1 y, and half for 2 y. In nonirrigated plots, oaks
grown from acorns that survived initial seed predation survived
significantly better than oaks planted from containers.
Across stock type (acorns, plants of different ages, and different
sizes of containers), initial differences in plant height
remained after 18 mo of growth, but growth rates were similar.
Oaks grown in containers usually had more branched and more
distorted root systems but all stock types successfully produced
deep roots. Irrigated plants grew faster than nonirrigated plants.
Plants weaned from irrigation during their second year grew as
well thereafter as those that were never irrigated.

Issue & Pages:

Spring 2005 Pages: 83-90

Article Download:

6-1NPJ83-90.pdf (PDF document)

Authors:

• Truman P Young
• Richard Y Evans

Keywords:

restoration, container size, seed predation, taproots, weaning, Quercus lobata