Search Results

You are looking at 1 - 10 of 16 items for

  • Author or Editor: L.K. Snelling x
Clear All Modify Search

Branches of Fraser fir [Abies fraseri (Pursh) Poir.] and eastern white pine (Pinus strobus L.) were subjected to various temperatures, vapor pressure deficits (VPD), and light regimes in controlled-environment chambers. Drying rates, based on measurements of needle water potential (ψ), were accelerated by increasing VPD, high temperature, and light. Fraser fir and white pine dried to – 4.0 MPa and – 3.0 MPa, respectively, in about the same time. The relationship of moisture content (MC) to ψ was linear for Fraser fir, quadratic for white pine. The MC of Fraser fir at – 4.0 MPa was also a linear function of VPD during drying. Water loss was greatest early in the drying cycle, and high temperature (25C) promoted rapid drying, even at low VPD.

Free access

Postharvest drying of Leyland cypress [× Cupressocyparis leylandii (A.B. Jacks. & Dallim.)] branches was intermediate between eastern red cedar (Juniperus virginiana L.) and Fraser fir [Abies fraseri (Pursh) Poir.] in two laboratory experiments. Leyland cypress rehydrated without adverse effect until xylem pressure potential reached –4.0 to –5.0 MPa (shoot moisture content = 60% to 65%). For branches continuously maintained in water, Fraser fir and Leyland cypress kept equally well over 4 weeks of display, but Leyland cypress lasted longer than Fraser fir over 8 weeks. Postharvest keeping quality of Leyland cypress and Fraser fir was better than that of eastern red cedar.

Free access

Dormant branches of Fraser fir [Abies fraseri (Pursh) Poir.] Christmas trees were subjected to single doses of gamma radiation at levels ranging from 0 to 5.0 kGy (0 to 500 kRad). Significant needle loss resulted at doses ≥0.10 kGy and increased with radiation intensity. Irradiation discolored foliage and accelerated drying. Irradiation does not appear to be a viable way to meet insect quarantine requirements on cut Fraser fir Christmas trees.

Free access

Stem cuttings of Atlantic white cedar [Chamaecyparis thyoides (L.) B.S.P.] were collected in early June 1995, divided into two parts (distal tip and proximal segment), and rooted for 12 weeks in shaded containers outdoors. Total rooting was near 80%. Mist intervals of 8 and 15 min yielded the best rooting percentages and the least dieback and injury. Two rooting media were tested, with similar results. Rooting was slightly higher in Spencer-Lemaire Rootrainers (Hillson size), compared to RoPak Multi-pots (#45). More than 90% of the tips rooted, even without IBA treatment. Auxin improved rooting of stem segments, but the difference between IBA at 1.5 and 3.0 g·L-1 was small. Yield of cuttings suitable for transplanting or potting was 80% for tips, 58% for segments. Dividing stem cuttings into two or more parts allows multiplication of rooted propagules from a collection. Chemical name used: 1H-indole-3-butyric acid (IBA).

Free access

Fraser fir [Abies fraseri (Pursh) Poir.] Christmas trees were basal pruned (branches were removed from the lower 15 to 25 cm of the stem, i.e., handle) at heights ranging from 0.6 to 0.9 m up to 1.5 to 1.8 m tall, and were harvested 2 to 4 years later. Basal pruning reduced cutting time ≈25%, and baling time ≈10%. Commercial height and stem diameter were unaffected, but the average harvest weight of pruned trees 2.1 to 2.4 m tall (2 to 4 years after basal pruning) was reduced ≈1.4 kg.

Free access

Fraser fir [Abies fraseri (Pursh) Poir.] Christmas trees up to 3.2 m in height were sampled from 18 well-managed plantations in western North Carolina to determine the yield of decoration greenery (wreaths, roping). Trees were not sidesheared in the year of harvest. The proportion of branch material suitable for decoration greenery decreased with increasing height and crown taper, but crown density had no effect. Mean annual yield of decoration greenery (establishment in the field, until reaching an average height of 3.2 m 10 years later) was 1.9 to 2.3 kg/tree per year, respectively, for trees with medium or heavy crown density.

Free access

Various pruning treatments were evaluated to determine the best procedure to correct terminal bud loss in Fraser fir [Abies fraseri (Pursh) Poir.]. Removing the top node (expanding terminal and subterminal buds) soon after budbreak combined with light pruning of the major branches in the next two lower whorls best restored a normal leader. This procedure allowed one or more shoots just below the cut to become orthotropic leaders in the first growing season. All but one of these shoots were removed, and only a single leader was retained after growth matured in late August or September.

Free access

Drying and rehydration characteristics were measured for Atlantic white cedar [Chamaecyparis thyoides (L.) B.S.P.], Arizona cypress [Cupressus arizonica var. glabra `Carolina Sapphire' (Sudworth) Little], Leyland cypress [× Cupressocyparis leylandii (A. B. Jacks. & Dallim.)], Virginia pine (Pinus virginiana L.), and eastern white pine (Pinus strobus L.) Christmas trees. Species varied in drying rate, loss of mass during display, water use after rehydration, the relationship between moisture content and xylem water potential (Ψ), and keeping quality. Leyland cypress and Arizona cypress rehydrated from Ψ values as low as –5.0 MPa, and remained in good condition after rehydration. The critical moisture content for Virginia pine and white pine was between –2.5 and –3.0 MPa. The ability of Atlantic white cedar to rehydrate decreased quickly with time out of water, and water consumption dropped sharply within a few days after placement in water. Change in fresh mass varied from +1% for Arizona cypress to –29% for Atlantic white cedar. Keeping quality of Virginia pine was poor, even for trees that were placed in water the day of cutting.

Free access

Current-year shoots of Fraser fir [Abies fraseri (Pursh) Poir.] were sampled in Christmas tree plantations in western North Carolina. Needles were sampled at five positions on each shoot: 0% (proximal end), 25%, 50%, 75%, and 100% (distal end). At each position, needles were collected in a tight left-hand spiral beginning on the abaxial side (bottom) and ending on the adaxial side (top). Length, width, thickness, dry weight, and projected surface area were determined for each needle. Specific area (one-sided) averaged 45 cm2·g-1 and increased from the shoot base to the tip. On individual shoots, needle dimensions were maximal at the middle (50% position). Within sample positions, needle dimensions increased from the adaxial to the abaxial side. Needle length, weight, and area differed more than width or thickness by position. Needle surface area per centimeter of shoot was relatively stable. Regression models using shoot length, diameter, needle density, and average needle length or weight yielded good estimates of total foliage area and weight.

Free access