Concern over the increasing proportion of juvenile wood grown in second growth plantations has led to a large amount of research on the effects of common silvicultural practices on wood quality. Lacking is research on the effect of timing and
duration of vegetation control on wood quality near the pith...
Ten herbicides (atrazine, azafenidin, chlorsulfuron, clopyralid, hexazinone, imazapic, imazapyr, metsulfuron, pendimethalin, and sulfometuron) were evaluated for phytotoxicity in first-year seedlings of eight conifer species (Douglas-fir, grand fir, noble fir, redwood, Sitka spruce, western hemlock, western red cedar, and western white pine). Six of these herbicides (atrazine, clopyralid, hexazinone, imazapyr, metsulfuron,...
The overall purpose of this study was to examine the root and shoot development of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seedlings at two distinct time periods in seedling establishment (after I and 3 growing seasons) in response to fertilizer, stock size, vegetation control, and soil moisture treatments. Two separate experiments...
A series of studies and replicated field sites were implemented in the Oregon Coast Range within Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) sapling plantations infected with varying levels of Swiss needle cast (SNC) caused by the fungus, Phaeocryptopus gaeumannii (Rhode) Petrak (PG). This research was conducted to understand the effects of...
Soil physical, chemical, and biological components as well as climate and physiographic characteristics can interact to have a great effect on forest regeneration and seedling growth response to different establishment activities. The objective of this project was to increase the understanding of the interactions between soil type, controlled-release fertilizers, and...
Two-year-old ponderosa pine (Pinus ponderosa Dougl. ex Laws.) seedlings from two Oregon seed sources were lifted three times in the fall, stored below freezing (-1.5°C), and compared to seedlings that were handled conventionally (spring lifting followed by short-term cold storage, 2-4°C). Based on patterns of budbreak in a greenhouse and...
To study the combined effects of seedling quality and fertilization at the time of planting, three experiments were established in western Oregon during the winter of 2000. The first experiment investigated the effect of preplanting rootvolume and fertilization rate on the field performance of 1+1 Douglas-fir seedlings during two growing...
Two-year old Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seedlings from two seed lots of different predicted hardiness levels were grown in two separate nurseries. Seedlings were lifted every four weeks from early October 1991 through March 1992 and exposed to controlled freezing temperatures. Fluorescence emissions of the seedlings were measured prior...
Approximately 3-4 month-old containerized Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seedlings (seed zone 262 and 271) were subjected to 6 moisture stress treatments (65, 53, 41, 29, 17 and 7% soil water content by volume of dry soil) starting July 4 to September 22, 1991 at Forest Research Laboratory's greenhouse at...
Transplant shock was induced by applying a range of soil water contents to unstored and cold-stored two-yearold (2+0) bareroot Douglas-fir seedlings graded by root volume. Moisture stress had the greatest influence on
morphological characteristics commonly associated with transplant shock. Terminal growth, lateral growth, stem diameter growth, and needle length increased...
Coastal Douglas-fir (Psuedotsuga menziesii (Mirb.) Franco) 1 + 1 seedlings were fertilized with two types of fertilizers (NB4NO3+K2SO4 and (NH.4)2 SO4+KC1) at four rates (0, 80, 160, 320 kg N and K/ha) split over 3 application dates (September 19, October 13, November 1, 1996). By January 10, total Kjeldahl nitrogen...
Douglas-fir (Psudotsuga menziesii (Mirb.) Franco) seedlings were outplanted on eight dates (every three weeks from mid-August 2005 through mid-January 2006). On each plant date, seedlings from a conventional dormancy (CONV) induction treatment, including moisture and nutrient stress, and a shortened daylength (SD) treatment were outplanted on three western Oregon sites...
The influence of shading intensity on performance, chlorophyll fluorescence emissions, the slope of the fluorescence induction curve, chlorophyll contents, and stomatal conductance of four Pacific Northwest conifer species [ponderosa pine (Pinus ponderosa Laws.), Douglas-fir
(Pseudotsuga menziesii (Mirb.) Franco), western redcedar (Thujaplicata Donn.), and western hemlock (Tsuga heterophylla (Raf.) Sarg.)] was...
Early in the establishment of Pacific Northwest conifer plantations, herbaceous weeds often decrease seedling growth through competition for soil moisture during the dry summer months. Critical period studies have reported that reductions in competitive weed cover are necessary during the initial years of establishment to avoid reductions in seedling growth....
Two-year-old ponderosa pine (Pinus ponderosa Laws.)
from two seed sources were grown at two nurseries. The
Fremont seed source was raised at Bend and Stone Nursery;
the Ochoco was grown at only the Bend Nursery. The
seedlings were fertilized in late September-early October
with nitrogen (N) or nitrogen plus potassium...
Two-year-old Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco] seedlings of two seed sources raised in three nurseries in Oregon and Washington were tested for differences in frost hardiness from September 1985 to March 1986. The objective of the study was to determine whether nursery location had an influence on seedling acclimation, deacclimation...