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Amy N. Wright, Alex X. Niemiera, J. Roger Harris, and Robert D. Wright

The objective of this study was to determine the effects of lime and micronutrient amendments on growth of seedlings of nine container-grown landscape tree species in two pine bark substrates with different pHs. Acer palmatum Thunb. (Japanese maple), Acer saccharum Marsh. (sugar maple), Cercis canadensis L. (redbud), Cornus florida L. (flowering dogwood), Cornus kousa Hance. (kousa dogwood), Koelreuteria paniculata Laxm. (golden-rain tree), Magnolia ×soulangiana Soul.-Bod. `Lennei' (magnolia), Nyssa sylvatica Marsh. (blackgum), and Quercus palustris Müenchh. (pin oak) were grown from seed in two pine bark substrates with different pHs (pH 4.7 and 5.1) (Expt. 1). Preplant amendment treatments for each of two pine (Pinus taeda L.) bark sources were: with and without dolomitic limestone (3.6 kg·m–3) and with and without micronutrients (0.9 kg·m–3), and with and without micronutrients (0.9 kg·m–3), supplied as Micromax. Seedlings were harvested 12 and 19 weeks after seeds were planted, and shoot dry weight and tree height were determined. The same experiment was repeated using two of the nine species from Expt. 1 and pine bark substrates at pH 5.1 and 5.8 (Expt. 2). Seedling shoot dry weight and height were measured 11 weeks after planting. For both experiments, pine bark solutions were extracted using the pour-through method and analyzed for Ca, Mg, Fe, Mn, Cu, and Zn. Growth of all species in both experiments was greater in micronutrient-amended than in lime-amended bark. In general, adding micronutrients increased nutrient concentrations in the pine bark solution, while adding lime decreased them. Effect of bark type on growth in Expt. 1 was variable; however, in Expt. 2, growth was greater in the low pH bark than in the high pH bark. In general, nutrient concentrations in bark solutions were higher in low pH bark than in high pH bark for both experiments. Under the pH conditions of this experiment, micronutrient additions stimulated growth whereas a lime amendment did not.

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W. Jack Rowe II, Daniel A. Potter, and Robert E. McNiel

Twenty-six purple- or green-leaved cultivars representing 12 species of woody landscape plants were evaluated in the field for defoliation by Japanese beetles (Popillia japonica Newman) over three growing seasons. We further evaluated the hypothesis that, within closely-related plants, purple cultivars generally are preferred over green ones by comparing beetles' consumption of foliage in laboratory choice tests and their orientation to painted silk tree models baited with Japanese beetle lures. Cultivars of Prunus cerasifera Ehrh. and hybrids of that species [e.g., Prunus ×cistena (Hansen) Koehne, Prunus ×blireiana André] were more heavily damaged than nearly all other plants tested. Among maples, Acer palmatum Thunb. `Bloodgood' and A. platanoides L. `Deborah' and `Fairview' were especially susceptible. None of the cultivars of Berberis thunbergii DC, Cercis canadensis L., Cotinus coggygria Scop., or Fagus sylvatica L. were heavily damaged, regardless of foliage color. In the choice tests, purple Norway maples were preferred over green ones in three of four comparisons, but preference varied within the other plant genera. In fact, more beetles oriented to green-leaved tree models than to purple ones. Our results indicate that within a genus, purple-leaved plants do not necessarily sustain more damage than green-leaved ones. Widespread use of certain purple-leaved cultivars of generally susceptible plant species probably contributes to the perception that purpleleaved plants, overall, are preferred. Purple-leaved cultivars of redbud, European beech, smoketree, and barberry, or the purple-leaved Prunus virginiana L. `Canada Red' or Malus ×hybrida Lemoine `Jomarie' may be suitable substitutes for more susceptible purple-leaved plants in landscapes where Japanese beetles are a concern.

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A.M. Shirazi and M.V. Thierry

It is not well known how cold-hardy new buds and emerging leaves or flowers are during spring. Extreme temperature fluctuations that sometimes bring early frost in spring (April–May) are very common in northern latitudes and cause severe damage to emerging leaves and flowers. Even though most woody plants can tolerate frost in spring, others show early tissue damage and can fully recover. There are some trees, e.g., Japanese maples (Acer palmatum) that when leaves are damaged due to spring frost, the results include severe dieback and eventual death. We tested new flowers and leaves of four crabapples: Malus ×micromalus, M. sargentii, `Mary Potter', and M. hupehensis, after budbreak for 3 years using electrical conductivity (EC) and differential thermal analysis (DTA) in spring: May 1997, Apr. 1998, and Apr. 2000, at The Morton Arboretum. Both flowers and leaves can tolerate from –6 to –12 °C and we observed higher ion leakage in leaves than flowers. The high temperature exotherm (HTE) of flowers were –8 to –10 °C in April. In a companion study, testing other species that had premature budbreak due to “near lethal” (sublethal) freezing stress in Jan. 2001, the following HTE were observed: Cornelian cherry (Cornus mas) flower (about –7.5 °C), Spindle trees leaves (about –6 °C), Judd's viburnum (Viburnum ×juddii) (about –8 °C), Brevipetala witch-hazel (Hamamelis mollis`Brevipetala') flower (about –5 °C), redbud (Cercis candensis) flower (about –9 °C), flowering quince (Chaenomeles ×superba) flower (–8 °C). Multiple LTE at –13, –18, –22, and –27 °C were observed for Judd's viburnum. This information could be useful for selection and breeding of woody plants.

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Dewayne L. Ingram and Charles R. Hall

CO 2 e to the GWP for Acer rubrum (red maple) ( Ingram, 2012 ), Picea pungens (blue spruce) ( Ingram, 2013 ), and Cercis canadensis (redbud) ( Ingram and Hall, 2013 ), respectively, from propagation to the nursery gate. Accounting for carbon

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Adam O. Maggard, Rodney E. Will, Thomas C. Hennessey, Craig R. McKinley, and Janet C. Cole

redbud ( Cercis canadensis ) (Cedar Valley Nurseries, Ada, OK) were planted within each of the plots. On 20 Apr. 2009, 46.5 gal of mulch was spread on each mulched plot to a depth of 3 to 4 inches. In addition to the trees, four individuals of six species

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Taryn L. Bauerle, William L. Bauerle, Marc Goebel, and David M. Barnard

‘Rubrum’), hornbeam ( Carpinus betula ‘Columnaris’), redbud ( Cercis canadensis ), and birch ( Betula nigra ‘Cully’). Five replicates of 2-year-old liners per species were transplanted in Apr. 2010 into 15-gal pots (44 cm wide × 38 cm deep) containing a

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Dewayne L. Ingram, Charles R. Hall, and Joshua Knight

tree [red maple ( Acer rubrum )], field-grown evergreen tree [blue spruce ( Picea pungens )], field-grown flowering tree [‘Forest Pansy’ redbud ( Cercis canadensis )], field-grown deciduous shrub [juddi viburnum ( Viburnum × juddi )], field

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Cynthia B. McKenney, Sandra A. Balch, Victor Hegemann, and Susan P. Metz

chart RHS London SPSS 2007 SPSS 15.0 statistical package SPSS Inc Chicago IL Tipton, J.L. 1992 Requirements for seed germination of Mexican redbud, evergreen sumac, and mealy sage HortScience 27 313

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Genhua Niu, Denise S. Rodriguez, and Wayne Mackay

redbud [ Cercis canadensis L. var. mexicana (Rose) M. Hopk.] contribute to water-conserving capability and survival in arid and semiarid regions compared with eastern redbud ( C. Canadensis ; Tipton and White, 1995 ). When plants are under drought

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Binoy Babu, Gary Knox, Mathews L. Paret, and Francisco M. Ochoa-Corona

, Raspberry leaf blotch emaravirus , Redbud yellow ringspot-associated emaravirus , and RRV were studied and genus broad–specific detection primers designed. The sensitivity of this RT-PCR was found to be 100 fg/reaction. The multiple Emaravirus detection