Ulmus Parvifolia Jacq Research Articles

FOLIAR ACCUMULATION OF ZINC IN TREE SPECIES GROWN IN PINE BARK MEDIA AMENDED WITH CRUMB RUBBER

Incorporated crumb rubber (CR) increased Zn tissue levels up to nine times the normal range in tree species. There was a linear increase in Zn tissue accumulation with increasing percentages of crumb rubber for river birch (Betula nigra L.), lacebark elm (Ulmus parvifolia Jacq.), and pecan [Carya illinoinensis (Wangenh.) C. Koch]. Pecan leaves containing high levels of Zn exhibited no visual symptoms, unlike the remaining tree species exhibiting leaf chlorosis. Results suggest that crumb rubber incorporated at rates greater than 25% may cause abnormally high concentrations of Zn to accumulate in plant tissue.

Irrigation and Fertilizer Placement Affect Root and Canopy Growth of Trees Produced in In-ground Fabric Containers

Abstract Live oak (Quercus virginiana Mill.) and Chinese elm (Ulmus parvifolia Jacq. ‘Drake’) were transplanted from 3.8 liter (#1) containers into 35-cm (14 in) fabric containers in sandy soils. Irrigation or fertilizer was applied all inside, half-in half-out (50/50), or all outside the fabric container during a 2-year production cycle. For live oak, neither irrigation nor fertilizer placement increased fine root mass within the fabric container. Maximum trunk diameter was achieved by applying both irrigation and fertilizer inside the container. For Chinese elm, applying either fertilizer or irrigation inside or half-in half-outside the container increased fine root mass within the harvested root ball. Elm shoot growth was greatest with 50/50 placement of both irrigation and fertilizer. Field site influenced the effect of Irrigation on shoot growth, but not root mass. Greater fine root mass occurred in the heavier soil type

Seasonal Cold Hardiness Differences of Three Woody Plant Taxa during the Production Stage and as Established Landscape Plants

Abstract Seasonal cold hardiness levels of Crape myrtle (Lagerstroemia L. ‘Natchez’), Leyland cypress [× Cupressocyparis leylandii (A.B. Jacks. and Dallim.) Dallim. and A.B. Jacks.] ‘Haggerston Gray’ and Lacebark elm (Ulmus parvifolia Jacq. Allee™) were determined for nursery production and established landscape plants grown at the same location. Differences in cold hardiness between the growth treatments were taxon specific. During October, November and December, nursery-grown crape myrtle plants were up to 11°C (20°F) less cold hardy than those established in the landscape. Differences in Leyland cypress cold hardiness were detected, but were not as great as in crape myrtle. During October, November and December newly transplanted Leyland cypresses were from 3 to 6°C (5 to 11°F) less cold hardy compared to established landscape plants. Differences occurred between nursery production and established landscape plants of lacebark elm in January and February.

629 (PS 3) ROOTING AND SUBSEQUENT GROWTH OF SUPERIOR LACEBARK ELM SELECTIONS BY HARDWOOD AND SOFTWOOD CUTTINGS

Numerous cultivars of Lacebark elm (Ulmus parvifolia Jacq.) have recently been introduced which are produced vegetatively. Conventional propagation is usually by softwood cuttings under intermittent mist which is quite successful. Softwood cuttings taken off two mature specimen trees stuck in May and June rooted 73 and 93 percent respectively at 10,000 ppm IBA but required overwinter protection prior to lining out the following season. Hardwood cuttings of numerous selections, stuck in perlite: peat (70:30 v/v) over bottom heat at 21°C in a cool greenhouse rooted 60 to 100 percent at 10,000 and 20,000 ppm. Cuttings from winter prunings were taken on February 4, potted by March 12, lined out May 23 produced 69 to 97 cm of growth the same season. The latter procedure offers a low input method of propagation which has several advantages over using softwood cuttings.

Shoot Regeneration from Leaf Explants of American and Chinese Elm

Shoots have been regenerated from greenhouse-grown Ulmus americana L. leaf sections on a modified Murashige and Skoog medium containing 0.1 μ m TDZ. After 2 months in culture, 73% ± 4% of explants treated with 0.1 μm TDZ produced 5.5 ± 3.5 shoots per explant. There was no variation in regeneration potential detected among the seedlings tested. In addition, shoots were produced from > 80% of leaf explants from Ulmus parvifolia Jacq. Chemical name used: N-phenyl-N′-l,2,3-thiadiazole-5′yl urea (TDZ).

Cold Hardiness of Six Cultivars of Chinese Elm

Cold hardiness levels of six cultivars of Chinese elm (Ulmus parvifolia Jacq.), `Select 380', `Orange Ribbon 740', `Emerald Isle', `Emerald Vase', `Drake', and `King's Choice', were determined over eight sample dates from 31 Aug. 1988 to 16 May 1989 and for `Emerald Vase' and `Drake', over three dates from 14 Feb. 1988 to 25 Apr. 1988. All cultivars tested achieved a maximum cold hardiness in December and January of – 21 to – 24C, except `King's Choice', which survived exposure to at least – 30C. `Emerald Isle' and `Emerald Vase' acclimated earlier (both – 9C on 31 Aug.) and reacclimated later (– 6 and – 9C, respectively, on 16 May) than other cultivars tested. `Emerald Vase' and `Drake' exhibited similar cold hardiness levels over the two years tested.

Response of five temperate deciduous tree species to water stress.

Gas exchange, tissue water relations, and leaf/root dry weight ratios were compared among young, container-grown plants of five temperate-zone, deciduous tree species (Acer negundo L., Betula papyrifera Marsh, Malus baccata Borkh, Robinia pseudoacacia L., and Ulmus parvifolia Jacq.) under well-watered and water-stressed conditions. There was a small decrease (mean reduction of 0.22 MPa across species) in the water potential at which turgor was lost (Psi(tlp)) in response to water stress. The Psi(tlp) for water-stressed plants was -1.18, -1.34, -1.61, -1.70, and -2.12 MPa for B. papyrifera, A. negundo, U. parvifolia, R. pseudoacacia, and M. baccata, respectively. Variation in Psi(tlp) resulted primarily from differences in tissue osmotic potential and not tissue elasticity. Rates of net photosynthesis declined in response to water stress. However, despite differences in Psi(tlp), there were no differences in net photosynthesis among water-stressed plants under the conditions of water stress imposed. In A. negundo and M. baccata, water use efficiency (net photosynthesis/transpiration) increased significantly in response to water stress. Comparisons among water-stressed plants showed that water use efficiency for M. baccata was greater than for B. papyrifera or U. parvifolia. There were no significant differences in water use efficiency among B. papyrifera, U. parvifolia, A. negundo, and R. pseudoacacia. Under water-stressed conditions, leaf/root dry weight ratios (an index of transpiration to absorptive capacity) ranged from 0.77 in R. pseudoacacia to 1.05 in B. papyrifera.

Water Relations of Container-grown Woody and Herbaceous Plants Following Antitranspirant Sprays

Four film-forming antitranspirants, Vapor Gard, Envy, Wilt-Pruf, and Folicote, and a new metabolic antitranspirant UC86177 were applied to container-grown Ulmus parvifolia Jacq. (Chinese elm), Malus sargentii Rehd. (Sargent's crabapple), Viburnum plicatum tomentosum Thunb. (doubleflle viburnum), Lycopersicon esculentum Mill. `Early Giant' (tomato), Petunia × hybrids Hort. Vilm-Andr. `Royal Pearls' (petunia), and Impatiens wallerana Hook. f. `Blitz Orange' (impatiens) plants. Water status was assessed by the following methods: transpiration as water loss per unit leaf area, wilt by visual evaluation, and xylem pressure potential (XPP) determined with a pressure chamber. Antitranspirant treatment had no beneficial effect on water status of doublefile viburnum. In comparison to control plants, results of wilt ratings, XPP, and transpiration measurements for the elm, crabapple, tomato, petunia, and impatiens plants can be summarized as follows: UC86177-treated plants showed significantly less stress in 11 measures and were not different once; Wilt-Pruf was beneficial 10 times and not different twice; Folicote was beneficial nine times and not different three times; Vapor Gard produced eight beneficial results and four similar results; and Envy was beneficial three times and no different nine times. Species differences in response to antitranspirants as well as differences in product efficacy were demonstrated. UC86177 antitranspirant was shown to be as or more effective in controlling water status than the film-forming antitranspirants and may have potential for protecting various plant species against water stress.

‘Aross Central Park’ Chinese Elm

Abstract Chinese elm (Ulmus parvifolia Jacq.) is an attractive, medium-sized ornamental tree with excellent urban-hardiness and pest resistance. Introduced into cultivation in the late 1700s, this species is commonly grown in parks, lawns, and streetside locations in the southern United States and California. There have been only three Chinese elm cultivars selected in this country (1, 2). Nurserymen have expressed their desire to find a Chinese elm with an increased level of cold hardiness so that the species could be used in cities in the northern United States. The ‘Aross Central Park’ Chinese elm is cold hardy to zone 6 (Arnold Arboretum hardiness zones) and will grow in protected areas in zone 5. Thus, it is the most cold hardy Chinese elm available.

Production System Comparisons for Selected Woody Plants in Florida

Abstract Quercus virginiana Mill., Magnolia grandiflora L., Liquidambar styraciflua L., Ulmus parvifolia Jacq. ‘Drake’, Lagerstroemia indica L., Ilex opaca Ait. ‘East Palatka’, and Pinus elliottii Engelm. were transplanted from 3-liter containers into 36-cm-diameter fabric Field-Gro containers, directly in the field into 36-cm-diameter auger-dug holes, or into 36-cm-diameter × 33-cm-tall black plastic containers. After 1 year, measured growth parameters of the Magnolia, Ulmus, Lagerstroemia, and Pinus were not affected by production system. Dry weight of Quercus and Liquidambar roots in the “harvest zone” were greater for trees grown in the fabric Field-Gro containers than those grown directly in the field. Quercus height and total carbohydrate content of Quercus and Magnolia primary root samples were increased by the fabric container. The above-ground container system clearly was inferior to the field-grown systems for production of the Quercus and Liquidambar under the conditions of this study.

‘Prairie Shade’ Elm

Abstract Since the urban population of American elms (Ulmus americana L.) was ravaged by Dutch elm disease fungus [Ceratocystis ulmi Buism. (C. Moreau)], attention has focused on the development of disease resistant elm hybrids. The cultivars ‘Sapporo Autumn Gold’, ‘Urban’, and ‘Regal’ are highly resistant to Dutch elm disease (7, 8, 9); however, they are extremely susceptible to the elm leaf beetle, (Pyrrhalta luteola Muller), because the susceptible Siberian elm Ulmus pumila L.) is a common parent (10). On the other hand, Ulmus parvifolia Jacq. (syn. U. sempervirens), U. chinensis Pers., sometimes listed incorrectly as the lacebark elm (syn. leatherleaf elm, Chinese elm) is highly resistant to Dutch elm disease and the elm leaf beetle (1, 2, 4, 10). Lacebark elm is native to central China, Japan, and Korea, is drought tolerant, and withstands the severe conditions often associated with urban sites (10). Like most other members of the genus Ulmus, lacebark elm is propagated by seed collected in the fall; however, Schopmeyer (6) indicated that less than 50% of the seeds are viable, and only 5% to 12% of the viable seed sown can be expected to produce saleable trees. Four asexually produced cultivars, ‘Sempervirens’, ‘Drake’, ‘True Green’, and ‘Dynasty’ (5), currently sold provide improved consistency and quality.

The Microscopy of Compatibility and Incompatibility in Ulmus

The American Elm (Ulmus americana L.) has been plagued by Dutch Elm Disease (DED), a lethal disease caused by the fungus Ceratocystis ulmi (Buisman) c. Moreau. Since its initial appearance in North America around 1930, DED has wrought inexorable devastation on the American elm population, triggering both environmental and economic losses. In response to the havoc caused by the disease, many attempts have been made to hybridize U. americana with a few ornamentally less desirable, though highly DED resistant, Asian species (mainly the Siberian elm, Ulmus pumila L., and the Chinese elm Ulmus parvifolia Jacq.). The goal is to develop, through breeding efforts, hybrid progeny that display the ornamentally desirable characteristics of U. americana with the disease resistance of the Asian species. Unfortunately, however, all attempts to hybridize U. americana have been prevented by incompatibility. Only through a firm understanding of both compatibility and incompatibility will it be possible to circumvent the incompatibility and hence achieve hybridization.

‘Dynasty’ Chinese Elm

Abstract The true Chinese elm (Ulmus parvifolia Jacq.) frequently has been confused with the Siberian elm (U. pumila L.) in American horticultural literature. This confusion undoubtedly has led to a lack of appreciation of the many excellent qualities of Chinese elm. Only 2 cultivars previously have been selected in the United States (1), both of which are semi-evergreen and grown largely in California. Well-formed trees of Chinese elm are not common. One of our nursery cooperators grew more than 2000 seedlings of this species for 7 years but did not find one to compare with our new cultivar ‘Dynasty’.

Selective Control of Trees by Pressure Injection of Herbicides1

Abstract Herbicides were introduced into the vascular systems of 20-and 22-year-old Chinese elm (Ulmus parvifolia Jacq.), pin oak (Quercus palustris Muenchh.), and 20-year-old white ash (Fraxinus americana L.) with a syringe-type pressure injector. Concentrations of triclopyr [[(3,5,6,-trichloro-2-pyridinyl)oxy]acetic acid] triethylamine salt ranging from 90 to 360 g/liter were as effective on all species with 2 injection sites per tree as the combination of picloram (4-amino-3,5,6-trichloropicolinic acid) triisopropanolamine salt + 2,4-D [(2,4-dichlorophenoxy) acetic acid) triisopropanolamine salt at dosages ranging from 8 g/liter + 30 g/liter to 32 g/liter + 120 g/liter. Over 80% kill of Chinese elm tops occurred within 2 months after injection, whereas maximum kill of white ash and pin oak did not occur until the following growing season.

Genetic Improvement of Elms and Other Tree Genera

An extensive selection and breeding program for disease resistant, stress tolerant elm clones is being carried out. Efforts have involved making controlled hybridizations for improvement of not only resistance to aggressive and nonaggressive forms of Ceratocystis ulmi but also variable growth rate, leaf size, and form. The many new selections include several American elms as well as horticulturally desirable hybrid clones from European and Asiatic crosses. These selections are currently being evaluated in nurseries and cities across the U.S. Research with red maples has demonstrated opportunity to select from among seed source progenies for superior growth rate, winter hardiness, stem straightness, and tolerance to Verticillium wilt, ozone, and drought. Seed source studies are also being conducted with the Chinese elm {Ulmus parvifolia Jacq.), blue spruce {Picea pungens Engelm.), and European black alder (Alnus glutinosa (L.) Gaertn).

Dikegulac: A Promising New Foliar-applied Growth Regulator for Woody Species1

Abstract Foliar application of 0.1 to 1% dikegulac-sodium [sodium 2,3:4,6-di-0-isopropyl-idene-2-keto-L-gulonate (Atrinal)] inhibited (shoot) elongation and axillary bud break for more than 3 months in field grown Xylosma congestum, (Lour.) Merr., Pyracantha coccinea (Roem.), Callistemon citrinus (Curt.), Cotoneaster pannosa (Franch.), and Nerium oleander L. Phytotoxic symptoms were minor in most species, but Nerium, chlorosis of young leaves and necrotic areas on tips of half expanded leaves were noted. Applications made immediately after pruning eliminated this problem. Fully expanded leaves were undamaged and their viability more than 5 months after treatment with 1% solutions were equal to that of control plants. Greenhouse trials with Eucalyptus globulus Labill., Fraxinus uhdei (Wenz.) lingelsh, and Ulmus parvifolia Jacq. indicated that this compound will also be a useful inhibitor for landscape tree species, although at 0.4%, phytotoxicity in Eucalyptus may be too severe for general application.

Relative Ozone Susceptibility of Selected Woody Ornamentals1

Abstract More than 1000 plants representing 15 species and/or cultivars of woody ornamentals were exposed to 0.25 ppm ozone for 8 hours at bi-weekly intervals throughout the 1973 growing season. A different set of plants were utilized in each bi-weekly exposure. Plants injured at this rate, in descending order of susceptibility, were Rhododendron obtusum Planch. ‘Hinodegiri’ (Hinodegiri Hiryu azalea), Rhododendron poukhanensis Leveille (Korean azalea), Ailanthus altissima Swingle (tree-of-heaven), Ulmus parvifolia Jacq. (Chinese elm), Philadelphus coronarius L. (sweet mock-orange), Viburnum setigerum Hance (tea viburnum), and Viburnum dilatatum Thunb. (linden viburnum). Plants resistant at this rate were Ilex crenata Thunb. ‘Hetzii’ (Hetz Japanese holly), Ilex opaca Ait. (staminate and pistillate American holly), Kalmia latifolia L. (mountain-aurel kalmia), Lingustrum amurense Carr. (amur privet), Nyssa sylvatica Marsh, (black gum), Taxus × media Rehd. ‘Densiformis’ (dense Anglojap yew), Taxus × media Rehd. ‘Hatfieldii’ (Hatfield Anglojap yew), and Tilia americana L. (American linden). The most common ozone symptom on the broadleaved plants was a tan or dark red to black stipple on the upper leaf surface. Premature defoliation occurred on susceptible plants. Plants were more susceptible to ozone in mid- to late summer than in early spring.

Defoliation Response of Woody Seedlings to Endothall/Ethephon1

Abstract Six species of seedling trees were foliar-treated in greenhouse experiments with 7 - ox ab icyclo(2,2,l)heptane-2,3-dicarboxylic acid (endothall) mixed with (2 chloroethyl) phosphonic acid (ethephon). A range of 75 to 100% abscission was obtained within 14 days with little or. no damage except on Chinese elm (Ulmus parvifolia Jacq.).

柑橘を害するコンドウシロミノガについて

In some parts of Togo-machi, Miyazaki-ken, the Kondo white psychid occurred in a orchard of Satsuma orange of 4-year old. Hibernating and gnawed vestiges were found on 14.8 % of trees investigated. One to 4 hibernating larvae were found per tree infested, with an exception of a tree with 47 larvae. Trees severely infested look whitish, and growth was inhibited, particularly in young trees. In addition to 25 species of host plants already reported, we confirmed 2, Ulmus parvifolia Jacq. and Viburnum awabuki K. Koch.