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  • Author or Editor: Eric Hinesley x
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Abstract

Eastern redcedar (Juniperus virginia L.) Christmas trees were cut in early December, brought indoors, and dried to different xylem pressure potentials (Ψ) before the stems were recut and placed in water. Redcedar trees dried rapidly, but quickly rehydrated even at Ψ as low as –6.5 to –7.0 MPa. Trees displayed negligible foliage loss while drying, but those dried to Ψ ≤ –4.9 MPa were predisposed to heavy defoliation following rehydration. There was a linear relationship between Ψ and twig moisture content (dry-weight basis).

Open Access

Orthotropic shoots (tips of primary axes) from 3-year-old Fraser fir seedlings [Abies fraseri (Pursh) Poir.] were grafted onto rootstocks of Fraser fir, Korean fir (A. koreana Wils.), momi fir (A. firma Sieb. & Zucc.), Nordmann fir (A. nordmanniana (Steven) Spach.), Turkish fir (A. bornmuelleriana Mattf.), and West Virginia balsam fir from Canaan Valley (Canaan fir) [A. balsamea (L.) Mill. var. phanerolepis Fern.]. Firstyear survival in the greenhouse was 92% to 98% except for momi fir (83%). The percentage of grafted plants with orthotropic shoots was 92% to 98%, except for Korean (81%) and momi fir (86%). Plants were subsequently established in replicated field experiments on three sites in the piedmont and mountains of North Carolina. In general, leader elongation of grafted Fraser fir scions was greater than leader growth on nongrafted transplants, including Fraser fir. Differences in survival appear to reflect interspecific variation in resistance to phytophthora root rot and/or tolerance of warm environments. Grafting may offer the potential to grow Abies Christmas trees on previously unsuitable sites, or to reclaim or continue using sites already seriously impacted by root rot.

Free access

Abstract

Three-year-old (3-0) Fraser fir seedlings were transplanted into an irrigated transplant bed at 2-week intervals between 1 Aug. and 15 Oct. and once the following spring prior to budbreak. Following one growing season in the transplant bed, seedlings established the previous August and early September had the greatest dry weight, stem diameter, and shoot elongation.

Open Access

Abstract

Two-year-old (2-0) Fraser Fir [Abies fraseri (Pursh) Poir.] seedlings were planted in a transplant bed and grown for 2 years under shade intensities of 0%, 30%, 51%, and 76%. Shade intensity of 30% had little effect on growth, but growth decreased significantly when shade intensity was increased from 51% to 76%. Plants grown in full sunlight or 30% shade were 2- to 2-times heavier and 75% larger in diameter than those grown under 76% shade. The effect of shade was similar for roots and shoots.

Open Access

Abstract

Fraser fir [Abies fraseri (Pursh) Poir.] Christmas trees were cut on 30 Nov. and air-dried for periods of 2, 5, 9, 13, 19, 22, 27 and 33 days, followed by recutting the butt ends and placing in water. Trees dried 9 days or less quickly rehydrated and reached twig moisture contents considerably higher than initial values. The rate and extent of rehydration declined with further drying; trees dried longer than 27 days continued to dry after being returned to water. Needle loss was not related to duration of drying or the quantity of water taken up after trees were returned to water. Xylem pressure potential was closely related to twig moisture content and seemed to be a rapid method of assessing freshness. The critical twig moisture content of Fraser fir, i.e., the moisture content below which a tree will not rehydrate when placed in water, was about 70% to 75%, which corresponded to pressure potentials of -40 to -45 bars.

Open Access

Eastern redcedar (Juniperus virginiana L.) seedlings were grown in 1986 through 1988 in pine bark container media with various levels of dolomitic limestone and micronutrients. Supplemental micronutrients reduced shoot growth, especially in the absence of limestone, and root growth was greatest when neither limestone nor micronutrients were added. Including at least 3.0 kg limestone/m3 in the medium was beneficial, not only as a source of nutrients, but also as a buffer against potentially toxic effects of excess micronutrients.

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).

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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.

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Fraser fir [Abies fraseri (Pursh) Poir.] Christmas trees were sheared once annually over 4 years on dates ranging from July to March. Shearing reduced total tree growth. Trees sheared in July and August had the highest quality and retail value. Early shearing (July and August) yielded fewer leaders, longer leaders, and 35% to 66% more internodal branches on the leader, compared to later shearing (September through March). Early shearing also yielded more second-order laterals, followed by greater elongation of those laterals. Shearing late into the fall yielded progressively fewer branches, with the minimum in October. Shearing in March gave a little better results than October, but neither date was as good as July or August. In one experiment, two types of residual tip buds (bubble and whisker) were compared as future leaders. Differences in length and straightness of leaders derived from whisker and bubble buds were considered negligible in commercial shearing practice. The ratio of adaxial and abaxial buds on the proximal portion of the leader was about 1:1, and showed little change with shearing date. Distance from the base of the leader to the first abaxial branch also showed little variation among shearing dates.

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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