An 18-hr photoperiod (LD) significantly increased cambial activity, rooting, bud respiration, and also hastened bud break of stem cuttings as compared with similar cuttings propagated under a 9-hr photoperiod (SD). Rooting response was modified by sampling date and temperature of the rooting medium. Rooting was least from August through November and greatest in December and January. Rooting temperatures of 18 and 26°C enhanced rooting without affecting bud activity.
. Don) ( Krasowski and Owens, 1991 ; Krasowski et al., 1990 ), and coastal douglas fir [ Pseudotsuga menziesii (Mirb.) Franco var. menziesii ] ( MacDonald and Owens, 2006 ). Control of height growth using SDs in recalcitrant, high-latitude British
two important Christmas tree species. Materials and Methods Douglas fir (Pseudotsuga menziesii). On 6 Feb. 2005, the commercially available SafeTree Christmas Tree Fire Retardant (Summit Environmental Corp., Longview, TX) was applied to 4
Container crops in the Pacific Northwest (PNW) are grown primarily in Douglas fir [ Pseudotsuga menziesii (Mirbel) Franco] bark (DFB). Similar to pine ( Pinus taeda L.) bark in the southeast U.S., DFB comprises the highest portion of most
porosity (TP), air space (AS), and container capacity (CC). The most common substrate components use in the Oregon nursery industry is douglas fir [ Pseudotsuga menziesii Mirb. (Franco)] bark (DFB), sphagnum peatmoss, and pumice. Each of these individual
American Blueberry Council, unpublished). In the past, common practice was to mulch with douglas fir [ Pseudotsuga menziesii (Mirb.) Franco] sawdust, which is readily available in the region but has become more expensive ( Julian et al., 2011 ). The
physical properties, and 3) directly measure water distribution in DFB in a 2.7-L container (#1 container). Materials and Methods Container height. Douglas fir ( Pseudotsuga menziesii ) bark samples of two different textures (screened to less
Container crops in the Pacific Northwest (PNW) are grown primarily in Douglas fir [ Pseudotsuga menziesii (Mirbel) Franco] bark (DFB). Similar to Loblolly pine ( Pinus taeda L.) bark in the southeast United States, DFB comprises the highest
Succulent branch terminal cuttings of Douglas-fir [Pseudotsuga menziesii (Mirb) Franco] placed horizontally (adaxial side up) curved slightly. Cuttings placed vertically, horizontally (adaxial side down), or on a horizontal clinostat exhibited significant adaxial-convex curvature. The response is regulated, in part, by substances exported from the needles and terminal bud. Gibberellic acid (GA3), (2-chloro-ethyl)phosphoric acid (ethephon), amino-ethoxyvinylglycine (AVG), indolebutyric acid (IBA), triiodobenzoic acid (TIBA), and 6-benzylamino purine (BA) failed to affect the curvature of vertically placed shoots.
and oriented in a north–south direction. Soil amendments. Three organic amendments were used in the study, including biochar, bokashi, and douglas fir [ Pseudotsuga menziesii (Mirb.) Franco] sawdust. The biochar was produced by gasification at