lighter colored containers on root growth and distribution may prove beneficial for a number of important nursery crops. Red maple and eastern redbud are examples of important species in the nursery industry because they are native to the United States
John W. Markham III, Dale J. Bremer, Cheryl R. Boyer, and Kenneth R. Schroeder
Franksred red maple (Acer rubrum `Franksred') trees were sampled from nursery fields in 2003 and 2004 to determine the cause of a common foliar chlorosis. Plots in 21 and 39 different nurseries were identified in 2003 and 2004, respectively. A single plot from each nursery was sampled in June of each year, whereas two to four plots per nursery were sampled in September. Each plot consisted of 20 consecutive trees in a single row. From each plot, a foliar tissue sample was analyzed for the complete range of essential nutrients. Plant height, stem diameter, leaf chlorophyll content, and a subjective plant quality rating were also recorded. From each plot, a soil sample was collected and analyzed for pH, EC, organic matter, and a range of essential nutrients. The foliar chlorosis was determined to be incited by manganese (Mn) deficiency. Tissue Mn was highly correlated with soil pH. Chlorotic plants were smaller with less stem diameter than nonchlorotic plants. Sufficiency ranges for tissue and soil tests were determined and are provided for red maple nursery production.
J. L. Sibley, D. J. Eakes, C. H. Gilliam, G. J. Keever, and W. A. Dozier Jr.
Average leaf area (LA) and petiole length (PL) was determined for 13 red maple selections May–Sept. 1993. Bloom types were determined based on the predominate flower structures present in Spring 1993 and 1994. Leaves were collected from an existing field study installed in Mar. 1990. Trees were drip-irrigated throughout the study, thereby eliminating moisture stress concerns. Acer×freemanii `Scarsen' (LA = 131.5 cm2), `Morgan' (LA = 93.6 cm2), and `Autumn Blaze' (LA = 83.9 cm2) had the largest leaves. Acer rubrum `Autumn Flame' (LA = 40.0 cm2) had the smallest leaves. Acer rubrum `October Glory' (PL = 17.1 cm) had the longest petioles followed by `Fairview Flame' (PL = 15.4 cm). Shortest cultivar petioles were on A. rubrum `Franksred' (PL = 9.3 cm) and `Tilford' (PL = 9.3 cm). Flowers were predominately pistillate on `Autumn Flame', `Franksred', `Morgan', `October Glory', `Redskin', `Scarsen', and `Schlesingeri'. Flowers were predominately staminate on `Fairview Flame', `Karpick', `Northwood', and `Tilford'. `Autumn Blaze' did not exhibit flowers in 1993 or 1994. Some seedlings in the study were pistillate, and others were staminate.
Dewayne L. Ingram and Charles R. Hall
overview As reported by Ingram and Hall (2015) , the functional unit for the PIP system in the lower midwest was also a 5-cm-caliper red maple in a no. 25 container. This model system was also based on interviews with four nursery managers and guided by
James J. Tobolski and Ricky D. Kemery
Dormant bud tissue from two or more trees representing 18 red maple (Acer rubrum L.) cultivars was subjected to isozyme analyses using starch-gel electrophoresis. Polymorphic enzymes resolved were alcohol dehydrogenase, peroxidase, phosphoglucase isomerase, glutamate oxaloacetate transaminase, leucine aminopeptidase, acid phosphatase, and malic dehydrogenase. An enzyme pattern or combination of patterns was useful in identifying individual cultivars, these included: `Autumn Blaze', `Autumn Flame', `Bowhall', `Celebration', `Columnare', `Curtis', `Doric', `Firedance', `Gerling', Y.J. Drake', `Morgan', `Northwood', `Scarlet Sentinel', `Schlesingeri', and `Tilford'. `Armstrong', `October Glory', and `Red Sunset' could not be distinguished from each other on the basis of enzymes examined in this study.
Edward F. Gilman and Michael E. Kane
Post-planting root development of red maple (Acer rubrum L.) on a well-drained site was compared with that on a site with a high water table. Container-grown red maple planted in 1985 were excavated in 1988 and cross-sectional root area (CSRA) calculated for roots >1 cm diameter, 5 cm beyond the edge of the original container rootball. Adventitious roots were generated in the field after planting, not in the container. Total adventitious CSRA was three times greater than CSRA of roots generated from the original container-produced root system. The number of adventitious roots (7.6) generated from the trunk and primary root after planting was greater than the number of roots originating from the existing root system (4.2). Adventitious root origin on both sites was within 5 cm of the soil surface, above the often circling, kinked, or twisted roots found within the container root ball. Four of the five largest roots were of adventitious origin. Root number, size, and growth rate were not modified by differences in cultural and environmental conditions between sites.
John M. Ruter and Jeff L. Sibley
In 1991, a cooperative project with the U.S. National Arboretum in Washington, D.C., was initiated in Tifton, Ga. (USDA hardiness zone 8a) to evaluate red maples (Acer rubrum L.) potentially suitable for the coastal plain region of the southeastern U.S. Greatest annual height growth across all cultivars over 6 years was for `Alapaha', a seedling selection from southern Georgia with annual height growth of 35 inches (88.0 cm), and several seedling selections from northern Florida with annual height increases in excess of 33 inches (86.0 cm). Selections showing the least average annual height growth were NA-56024 and NA-57772 (`Red Rocket'). For commercially available cultivars, the most dependable for fall color in Tifton was `October Glory'®. In addition, two new selections from the National Arboretum have also shown excellent fall color—`Somerset' and `Brandywine'.
Jeff L. Sibley, D. Joseph Eakes, Charles H. Gilliam, and William A. Oozier
Performance evaluation of red maple (Acer rubrum L.) selections in the southeastern U.S. was initiated in November 1988. Seven cultivars, `Autumn Blaze', `Autumn Flame', `Morgan', `Northwood', `October Glory', `Franksred' (Red Sunset TM) and `Schlesingeri', from tissue culture and a group of seedlings obtained from a single source were container grown for 18 months prior to field planting in March 1990. All plants have received drip irrigation in the field. Since field planting, 'Autumn Flame', and 'Autumn Blaze' exhibit the greatest growth rate based on annual height and caliper data. 'Schlesingeri' and 'Northwood' had the least growth. Gas-exchange measurements taken in June 1992, showed 'Schlesingeri' and 'Northwood' to have the greatest photosynthetic activity and transpirational water loss while 'October Glory' and 'Frankred' had the least.
Bruce R. Roberts, Virginia M. Schnipke, and Jack H. Barger
Two-year-old seedlings of red maple (Acer rubrum L.) were fumigated with SO2 (0.0, 0.5, 2.0, and 4.0 ppm) 8 hours daily for two 3-day periods spaced 3 days apart. Response to acute SO2 stress was determined by measuring changes in ethylene biosynthesis and membrane permeability. Ethylene evolution was a useful indicator of the onset of SO2 stress in red maple, but was not a particularly good indicator of the degree of stress. Membrane permeability was not as sensitive to the initial stages of SO2 stress, and significant changes in permeability were noted only at higher concentrations of this pollutant (> 2.0 ppm).
Matt Kelting, J. Roger Harris, Jody Fanelli, and Bonnie Appleton
Humate-based products have been aggressively marketed as biostimulants that increase plant growth. Little data are available on their effect on tree establishment or their interaction with fertilizer and irrigation regimes. This experiment tested several types of biostimulants on posttransplant growth of Acer rubrum L. (red maple) and Crataegus phaenopyrum (Blume) Hara (Washington hawthorn) trees, both with and without irrigation and fertilization. Soil treatments were applied at planting as: 1) control (native backfill only); 2) compost (native backfill + yard-waste compost); 3) peat (native backfill + Canadian sphagnum peat); 4) granular humate, 100 g/tree; 5) granular humate, 200 g/tree; and 6) liquid humate +, a proprietary liquid mixture of humate, kelp extract, thiamine, and intermediate “metabolites.” Irrigation regime × soil treatment interaction was significant for red maple, but soil treatments did not increase height, stem diameter, top dry mass, or root length. For Washington hawthorn, soil treatments did not increase height, stem diameter, or root length, but top dry mass in all treatments as a group and in humate-treated trees in particular was greater than that of controls. Roots of peat-treated trees of both species were longer than those in other treatments. Granular humate applied at 200 g/tree increased total root length more than did 100 g/tree in Washington hawthorn but not in red maple. Fertilizing at planting with N at 14.5 g·m-2 had no effect on any parameter measured for either species.