IntensIve sIlvIculture - Forest Science Labs - Research Network ...

growth
soil properties
203
Abstract: Replicated forest floor and surface soil (0-15 cm) samples were obtained from
control plots at 160 field installations in western Washington and Oregon. Six-year growth
responses of thinned and unthinned Douglas-fir [Pseudotsuga menziesii] treated with 0, 224, and
448 of urea-N ha-1 were correlated with 18 forest floor and surface soil properties of the control
plots. Forest floor nitrogen properties were the most highly correlated with various estimates of
response in both thinned and unthinned stands; these correlations were generally independent of
methods used to estimate response. For unthinned stands, C/N ratios of both forest floor and
surface soil were well correlated with growth response to fertilizer, whereas for thinned stands, N
content (kilograms per hectare) of the forest floor was consistently correlated with response.
465. Peterson, M. and J.R. Sutherland. 1989. Grey mould control by seedling canopy humidity
reduction through under-bench ventilation and styroblock aeration. B.C. Ministry of Forests
FRDA-Report 051. 15 p.
Keywords: nursery operations
growth
tree/stand health
tree morphology
Abstract: A discussion of nursery procedures for controlling Botrytis cinerea on containergrown
Pseudotsuga menziesii seedlings.
466. Peterson, M.J. and J.R. Sutherland. 1990. Controlling gray mold on container-grown Douglas-fir
by modified styroblocks and under-bench, forced air ventilation. Western-Journal-of-Applied-
Forestry 5(3): 75-79.
Keywords: nursery operations
tree/stand protection
growth
tree/stand health
Abstract: The control of grey mould (Botrytis cinerea) on Douglas fir (Pseudotsuga
menziesii) seedlings was investigated in Vancouver, Canada. Incidence of mould on seedlings
sown in June 1988 and assessed January 1989 was reduced in 3 treatments of modified
styroblocks (vertical holes, allowing air movement from below): vented with heated, forced air;
vented with unheated, forced air; and vented with unheated, unforced air. Overall, mould
occurred on 25% of 7-month-old seedlings in vented styroblocks, compared with >75% incidence
in unmodified styroblocks. No significant differences in seedling height or root collar diameter
among treatments were observed. Use of ventilated styroblocks is recommended, to reduce both
losses from grey mould and fungicide usage in nurseries.
467. Peterson, M.J. and S.E. Tuller. 1987. Die-back of container-grown Douglas-fir seedlings:
associated microclimate. B.C. Ministry of Forests FRDA-Report 035. vii + 43 p.
Keywords: nursery operations
tree/stand protection
tree/stand health