Bareroot Corylus colurna were grown in 7.5-liter containers from 11 Apr. until 27 June 1994. The growing medium was fritted clay. Fertility levels included no fertilization, 100 ppm N, or 200 ppm N. Plants were root pruned to remove none or one-quarter to one-half of the primary roots. Root pruning at any level resulted in decreased height, shoot, and root dry weights and number and length of new shoots. One-quarter primary root removal resulted in lower root: shoot ratios compared to plants that were unpruned. One-half primary root removal further reduced root: shoot ratios. One-half primary root removal also reduced total leaf area compared to unpruned controls. Fertilization at 200 ppm N increased leaf numbers and total leaf areas compared to plants receiving no fertilization.
Patricia R. Knight, James R. Harris, and Jody Fanelli
P.R. Knight, J.R. Harris, and J.K. Fanelli
Two-year-old, bareroot, Corylus colurna seedlings were grown in 7.5-L containers from 15 Mar. to 23 June 1995. Plants were grown in a glasshouse using pine bark media. Temperatures were maintained at 30/20°C. Plants received no fertilization or Osmocote 18–6–12 top-dressed at 14 or 28 g/container. Additionally, plants were pruned to remove 0%, 25%, or 50% of the root system based on root length. Height, diameter, branch number, leaf area, and root and shoot dry weight increased linearly as rate of fertilization increased. Percent embolism was not influenced by rate of fertilization. Plant height, branch number, leaf area, and root and shoot dry weight were not influenced by rate of root pruning. Plant diameter increased linearly as rate of root pruning decreased. Percent embolism increased linearly as rate of root pruning increased.
J. Roger Harris, Richard Smith, and Jody Fanelli
Rapid posttransplant root growth is often a determining component of successful establishment. This study tested the effect of transplant timing on first-season root growth dynamics of bare-root Turkish hazelnut trees. Trees were either harvested and planted in the fall (F-F), harvested in the fall and planted in the spring after holding in refrigerated storage (F-S), or harvested and planted in the spring (S-S). All trees were transplanted into 51-L containers, adapted with root observation windows. Root growth began in F-F and F-S trees 1-2 weeks before spring budbreak, but was delayed in S-S trees until ≈3 weeks after budbreak. Budbreak was 6 days earlier for fall-harvested than for spring-harvested trees. No new roots were observed before spring. Root length accumulation against observation windows (RL) was delayed for S-S trees, but rate of increase was similar to F-F and F-S trees soon after growth began. Seasonal height, trunk diameter growth, and RL were similar among treatments. Surface area of two-dimensional pictures of entire rootballs was not correlated with seasonal RL.
Xiaoling Yu and Barbara M. Reed
A micropropagation system was developed for hazelnut cultivars. Grafted greenhouse-grown plants produced many more viable explants than upper branches of mature field-grown trees. Shoots from grafted greenhouse-grown plants collected March through July and suckers of mature field-grown trees collected in July produced the most growing explants (46% to 80%). Three- to five-fold multiplication was obtained after 4 weeks of culture on NCGR-COR medium supplemented with 6.7 μm BA and 0.04 μm IBA. Roots were produced on 64% to 100% of shoots grown on half-strength NCGR-COR mineral salts and 4.9 μm IBA for 4 weeks. Ex vitro rooting by a brief dip in 1 or 5 mm IBA was equally successful. Transplant survival was 78% to 100%. Chemical names used: N 6-benzyladenine (BA); indole-3-butyric acid (IBA).
Roger Harris, Nina L. Bassuk, and Thomas H. Whitlow
Root and shoot phenology were observed, and root length within rootballs were calculated for Fraxinus pennsylvanica Marsh. (green ash), Quecus coccinea Muenchh. (scarlet oak), Corylus colurna L. (Turkish hazelnut), and Syringa reticulata (Blume) Hara `Ivory Silk' (tree lilac) trees established in a rhizotron. Easy-to-transplant species (green ash and tree lilac) had more root length within rootballs than difficult-to-transplant species (Turkish hazelnut and scarlet oak). Shoot growth began before root growth on all species except scarlet oak, which began root and shoot growth simultaneously. Fall root growth ceased for all species just after leaf drop. Implications for tree transplanting are discussed.
J. Roger Harris, Nina L. Bassuk, Richard W. Zobel, and Thomas H. Whitlow
Root and shoot growth periodicity were determined for Fraxinus pennsylvanica Marsh. (green ash), Quercus coccinea Muenchh.,Corylus colurna L. (Turkish hazehut) and Syriaga reticulara (Blume) Hara `Ivory Silk' (tree lilac) trees. Two methods for determining root growth periodicity using a rhizotron were evaluated. One method measured the extension rate of individual roots, and the second method measured change in root length density. A third method, using periodic counts of new roots present on minirhizotrons, was also evaluated. The root extension method showed the least variability among individual trees. Shoot growth began before or simultaneously with the beginning of root growth for all species with all root growth measurement methods. Species with similar shoot phenologies had similar root phenologies when root growth was measured by the root extension method, but not when root growth was measured by the other methods. All species had concurrent shoot and root growth, and no distinct alternating growth patterns were evident when root growth was measured with the root extension method. Alternating root and shoot growth was evident, however, when root growth was measured by the other methods.
J. Roger Harris, Nina L. Bassuk, Richard W. Zobel, and Thomas H. Whitlow
The objectives of this study were to determine root and shoot growth periodicity for established Fraxinus pennsylvanica Marsh. (green ash), Quercus coccinea Muenchh. (scarlet oak), Corylus colurna L. (Turkish hazelnut), and Syringa reticulata (Blume) Hara `Ivory Silk' (tree lilac) trees and to evaluate three methods of root growth periodicity measurement. Two methods were evaluated using a rhizotron. One method measured the extension rate (RE) ofindividual roots, and the second method measured change in root length (RL) against an observation grid. A third method, using periodic counts of new roots present on minirhizotrons (MR), was also evaluated. RE showed the least variability among individual trees. Shoot growth began before or simultaneously with the beginning of root growth for all species with all root growth measurement methods. All species had concurrent shoot and root growth, and no distinct alternating growth patterns were evident when root growth was measured by RE. Alternating root and shoot growth was evident, however, when root growth was measured by RL and MR. RE measured extension rate of larger diameter lateral roots, RL measured increase in root length of all diameter lateral roots and MR measured new root count of all sizes of lateral and vertical roots. Root growth periodicity patterns differed with the measurement method and the types of roots measured.
Honglin Chen, Shawn A. Mehlenbacher, and David C. Smith
filbert hybrids Ann. Rept. Northern Nut Growers Assn. 67 80 82 Farris, C.W. 1982 A progress report on the development of F 2 hybrids of Corylus colurna × C. avellana Annu. Rep. Northern Nut Growers Assn. 71 15
Bekir Şan, Adnan Nurhan Yildirim, and Fatma Yildirim
on seed germination of Turkish hazel ( Corylus colurna L.) Acta Hort. 845 203 206 Baskin, J.M. Baskin, C.C. 1997 Methods of breaking seed dormancy in the endangered species Iliamna corei (Sherff) Sherff (Malvaceae), with special attention to
Donita L. Bryan, Michael A. Arnold, Astrid Volder, W. Todd Watson, Leonardo Lombardini, John J. Sloan, Luis A. Valdez-Aguilar, and Andrew D. Cartmill
practices. For example, Day and Harris (2008) reported that growth and establishment of Corylus colurna L. (Turkish hazel) trees was not impaired after nearly 8 years by planting root collars 15 cm or 30 cm below grade compared with at grade in a well