L.E. Hinesley, L.K. Snelling, and Scott Goodman
Amanda J. Taylor, R. Thomas Fernandez, Pascal Nzokou, and Bert Cregg
) using an 80:20 (v:v) mix of pine bark and peatmoss (Renewed Earth, Inc., Kalamazoo, MI). Container capacity of the media was 44.5%. The four species used were Fraser fir [ Abies fraseri (Pursh) Poir.], Colorado blue spruce ( Picea pungens Engelm. var
Jennifer L. Emerson, John Frampton, and Steven E. McKeand
Fraser fir ( Abies fraseri ) is the only fir species native to the southern United States, and it is found naturally only in a few stands at elevations of about 1300 m to over 2000 m in western North Carolina, eastern Tennessee, and southwestern
Robert J. Richardson and Bernard H. Zandstra
. 16 762 767 10.1614/0890-037X(2002)016[0762:FPBWMI]2.0.CO;2 Richardson, R.J. Zandstra, B.H. 2005 Hoary alyssum ( Berteroa incana ) control in fraser fir ( Abies fraseri ) Christmas trees Weed Sci. Soc. Amer. 45 33 (Abstr.). Richardson, R.J. Zandstra, B
Stuart L. Warren, C. Ray Campbell, and Walter A. Skroch
Fraser fir [Abies fraseri (Pursh) Poir.] and Norway spruce [Picea abies (L.) Karst.] were grown in seven vegetation management programs ranging from 100% cover of grass-dominated vegetation to bare soil on opposing north and south aspects. Concentrations of 13 nutrients were determined at three growth stages during 2 years: active terminal growth, cessation of terminal expansion, and dormancy. Aspect did not affect nutrient concentrations. Vegetation management programs bad a significant impact on nutrient concentration for both species. Nitrogen, Ca, B, Fe, and Mn concentrations during dormancy were negatively correlated with herbaceous biomass. In contrast, N during active growth and P and Mg concentrations during all stages were positively correlated with herbaceous biomass. Vegetation management only affected the seasonal trend of Mo. Seasonal trends varied by nutrient in both species.
Carole H. Saravitz, Frank A. Blazich, and Henry V. Amerson
Hypocotyls of Fraser fir (Abies fraseri (Pursh) Poir.) were excised from seeds germination 9 days and placed on bud induction medium containing 10 mg/liter benzyladenine (BA) and 0.01 mg/liter naphthaleneacetic acid (NAA) or medium without growth regulators. After 3 days on medium containing growth regulators, cell divisions were localized in epidermal and subepidermal layers of the hypocotyl while similar cell divisions were not observed in control-treated hypocotyls. Cell clusters consisting of two to five cells were present after 7 days in hypocotyls placed on bud induction medium. In control-treated hypocotyls, stomata continued to develop and cells within the cortex became vacuolated during the first 2 weeks in culture. All hypocotyls were transferred to secondary medium after 3 weeks. Cell clusters continued to enlarge into meristemoids in hypocotyls initially placed on bud induction medium. Gradually, meristemoids developed into buds and cataphylls were observed covering bud meristems.
M. Elizabeth Rutledge, John Frampton, L. Eric Hinesley, and Gary Blank
The Top-Stop Nipper (TSN), a four-bladed, hand-held tool used to reduce leader growth in Christmas trees, was evaluated on fraser fir (Abies fraseri). The TSN placed incisions (nips) on the previous year's leader to reduce the amount of photosynthate transported to the developing leader. Treatments consisted of a control (zero nips), and one, two, three, or four nips at each of three stages of leader elongation (pre-budbreak, 2–3 cm, and 6–9 cm). The TSN significantly reduced leader elongation. The percentage of leaders that were within the target range of 8 to 14 inches (20.3–35.6 cm) increased from 18% for the control (no nips) to 46% with four nips. The TSN, when combined with traditional knife shearing or growth regulator treatments, might offer a method to produce dense trees with minimal shearing or to leave longer leaders to produce a more open “European-style” tree during a shorter rotation time.
John Frampton and D.M. Benson
Seventeen-month-old seedlings from three fraser fir (Abies fraseri [Pursh] Poir.) seed sources (Mount Mitchell, Richland Balsam and Roan Mountain) were inoculated in an outdoor lath house with five genotypes of Phytophthora cinnamomi Rands. After 122 days, overall mortality was 90.5% with significant (p ≤ 0.07) differences among seed sources. The Mount Mitchell source had lower mortality (83.2%) than the Roan Mountain source (95.8%), while the Richland Balsam source (92.5%) was intermediate. Mortality curves were developed using nonlinear regression (Richards' function). Due to a significant seed source × inoculum genotype interaction (p ≤ 0.0001), equations were developed for each combination of seed source and inoculum genotype. Results suggest that while the overall frequency of resistance in fraser fir is low, seed sources differ in their frequency of resistance and that more than one resistance gene may be present. Survivors from this or similar inoculations could be cloned via grafting or rooted cuttings for further resistance testing and/or grafted into a Phytophthora-resistant fraser fir seed orchard.
M. Elizabeth Rutledge, John Frampton, L. Eric Hinesley, and Gary Blank
The Top-Stop Nipper (TSN), a four-bladed, hand-held tool developed for reducing leader growth of Christmas trees, was used as a wounding technique to reduce leader growth of Fraser fir (Abies fraseri). A regression model, based on an apical bud volume index (average bud diameter squared × length), was used to predict the number of nips to apply to each leader to yield a target length of 25 to 36 cm. Treatments included control trees (0 nips) and one to seven nips per leader. Nips were applied in May at budbreak. In an earlier study, increasing the number of nips decreased leader elongation when randomly applied to trees without regard to the size of the apical bud. In this study, when the number of nips increased with increasing bud volume index, leader growth was similar among all TSN treatments. Bud density (per unit length) on the 2006 leader increased with the number of nips applied to the 2005 leader. Results might be useful for growers who want to produce dense trees with minimal shearing or for growers who choose to leave a longer leader to produce a more open, “European-style” tree during a shorter rotation time.
Nirmala Rajbhandari and Anne-Marie Stomp
Mass propagation of Fraser fir [Abies fraseri (Pursh) Poir], a valuable Christmas tree species in the United States, is problematic because methods currently used are inadequate. According to our results with somatic embryogenesis, the culturing methods used with other Abies species are applicable to Fraser fir. Stage 1 somatic embryogenic callus, characterized by suspensor cells and embryo heads, was obtained at low frequency using Schenk and Hildebrandt medium supplemented with 5 mm glutamine, 0.05% casein hydrolysate, 0.01% myoinositol, 2% sucrose, 5 μM benzyladenine, and 0.6% agar. The developmental stage of the embryo was important; embryogenic callus was obtained only with immature, precotyledonary embryos, not with fully formed embryos. Cold storage of cones containing immature embryos inhibited callus proliferation. Genotype was significant in that 35 of 44 families tested proliferated callus; however, only one embryo within one family continued proliferation to produce stage 1 embryogenic callus. Fully formed somatic embryos were not produced because the callus did not continue to proliferate. Although these experiments met with only limited success, they demonstrate the potential for somatic embryogenesis in Fraser fir and the general applicability of methods used with other Abies species.