bluuebunny/crossref_metadata_2025 huggingface dataset:
Cutless and Atrimmec for Controlling Growth of Woody Landscape Plants in Containers
Authors: Banko Thomas J. , Stefani Marcia A.
Published: August 2020

Cutless (flurprimidol) effectively reduced shoot elongation of container-grown woody ornamentals, including abelia, cotoneaster, crape myrtle, Foster holly, Mystery gardenia, Manhattan euonymus, photinia and rhododendron. Optimum Cutless 50W (flurprimidol) spray rates were 500–600 ppm for most species except for Manhattan euonymus (1250 ppm), Mystery gardenia and Natchez crape myrtle (750 ppm). Optimum Cutless 0.33G (flurprimidol) granular rates were 0.6 kg/ha (0.5 lb/A) for Coral Beauty cotoneaster and Foster holly, and 1.7 kg/ha (1.5 lb/A) for Fraser photinia. Atrimmec (dikegulac) was effective in controlling growth of abelia at spray rates of 1480 ppm, Coral Beauty cotoneaster, and Manhattan euonymus at 1600 ppm, Foster holly, and Fraser photinia at 4440 ppm. Neither Off-Shoot-O nor Trim-Cut (mefluidide) had a significant effect on any of the species studied. None of the growth regulators had a significant effect on nandina.
Validity of Screening for Foliage Cold Hardiness in the Laboratory
Authors: Johnson G.R. , Hirsh Allen G.
Published: August 2020

Thirty-five broadleaf evergreens which are evergreen in USDA cold hardiness Zone 7 were screened using leaf discs in the laboratory for Zone 6 (-20C) temperatures. Field data were collected from the plants in the field after two consecutive nights with lows of-20C. Correlations between lab and field scores were high, demonstrating the usefulness of leaf discs in initially screening broadleaf evergreens for evergreeness. The method allows for a more thorough sampling of a taxon and may therefore give better results than using a limited number of larger leaf samples, such as whole leaves. A number of the tested taxa should prove evergreen in Zone 6, including: Camellia oleifera Abel ‘Lu Shan Snow’, Viburnum L. Arrowwood ‘Conoy’, Viburnum rhytidophyllum Hemsl. ‘Cree’, and certain selections of Pyracantha M.J. Roem, Illicium anisatum L., Quercus acuta Thunb., Quercus myrsinifolia Blume and Daphniphyllum macropodum var. humile Miq.
Responses to High Root-zone Temperature Among Cultivars of Red Maple and Freeman Maple
Authors: Wilkins Lorna C. , Graves William R. , Townsend Alden M.
Published: August 2020

Two experiments were conducted to determine whether genotypes of red maple (Acer rubrum L.) and Freeman maple (A. x freemanii E. Murray) differ in responses to high root-zone temperature. During the first experiment, dry mass of ‘Franksred’, ‘October Glory’, and ‘Schlesinger’ red maple, ‘Indian Summer’ Freeman maple, and selections from Arkansas, Maine, and Wisconsin were similar at 24, 28, and 32C (75, 82, and 90F), but dry mass at 36C (97F) was only 22% of that at 28C (82F). ‘Autumn Flame’, ‘Franksred’, ‘October Glory’, and ‘Schlesinger’ red maple and ‘Indian Summer’ and ‘Jeffersred’ Freeman maple differed in responses to 34C (93F) during the second experiment. Stem length and plant dry mass were higher at 28C (82F) than at 34C (93F) for all cultivars except ‘Autumn Flame’ and ‘Jeffersred’, and the extent to which 34C (93F) decreased the length of the longest third-order root ranged from 50% for ‘Autumn Flame’ to 90% for ‘Indian Summer’. The higher root-zone temperature decreased transpiration by as little as 25% for ‘Jeffersred’ to as much as 89% for ‘Franksred’, and 34C (93F) reduced leaf chlorophyll content of only ‘Indian Summer’ and ‘Jeffersred’. These results indicate that ‘Franksred’ and ‘Indian Summer’ are relatively sensitive while ‘Autumn Flame’, ‘Jeffersred’, and ‘Schlesinger’ are relatively resistant to high root-zone temperature.
Seed Source Affects Seedling Development and Nitrogen Fixation of Maackia amurensis
Authors: Pai J. Giridhar B. , Graves William R.
Published: August 2020

Seeds of Maackia amurensis Rupr. & Maxim. were obtained from 38 sources, and 2,393 seedlings were examined for variation in plant growth and development. Mean stem length and number of leaves per plant after 21 months ranged from 10 to 40 cm (4 to 16 in) and from 6 to 13, respectively, among seedlings from different sources. The mean product of length and width of a representative leaflet was 362 to 1510 mm2 (0.6 to 2.3 in2) among sources. A subset of seven seed sources was used to determine how seedling growth, root nodulation, and N content of shoots are influenced by applied N and inoculation with Bradyrhizobium. Plants from the seven sources varied in nodule dry mass and shoot N. Mean stem length, laminar area, and dry mass of plants provided N and grown in uninoculated medium were higher than those of plants not provided N regardless of inoculation. When N was not provided, inoculation increased N in shoots but did not affect growth. Nodule dry mass of plants in inoculated medium was correlated positively with surface area of lamina. Variation among seedlings provides a basis for selecting genotypes that produce high nodule mass and grow rapidly.
Evaluation of Entomopathogenic Nematodes as Biological Control against the Banded Ash Clearwing Borer
Authors: Smith-Fiola Deborah C. , Gill Stanton A. , Way Robert G.
Published: August 2020

Three species of entomopathogenic nematodes were evaluated for suppression of the banded ash clearwing borer (BACB; Podosesia aureocincta) attacking green ash (Fraxinus pennsylvanica). Field trials were located in Howard County, Maryland (shopping mall parking lot), utilizing Steinernema carpocapsae and S. feltiae, and Ocean County, New Jersey (suburban street trees), utilizing Steinernema carpocapsae, S. feltiae, and S. glaseri. Nematodes were applied as bark sprays in June (NJ), July (MD), and October (NJ) using a backpack sprayer. Examination of pupal exuviae and/or adult emergence revealed reduced BACB populations in 7 of 9 nematode treatments, with control ranging from 12-54 percent. Nematode sprays applied to dry bark did not provide acceptable control.
Evaluating Pulp and Paper Sludge as a Substitute For Peat Moss in Container Media
Authors: Tripepi Robert R. , George Mary W. , Campbell Alton G. , Shafii Bahman
Published: August 2020

Pulp and paper sludge from a newsprint mill was composted for 6 weeks and evaluated as a substitute for peat moss in container media. One-year-old seedlings of lilac (Syringa vulgaris L.) and amur maple (Acer tataricum L. ssp. ginnala (Maxim.) Wesm.) as well as rooted cuttings of cistena plum (Prunus × cistena Hansen) were planted in #1 plastic pots that contained a pine bark and sand mixture (2:1 by vol) or pine bark and sand amended with either 25% or 50% peat moss or composted paper sludge. A 75% compost medium that consisted of composted paper sludge and sand (3:1 by vol) was also used in the study. Plant height was measured every 4 weeks. After 14 weeks of growth, shoot dry weight and final plant height were measured. All plants in compost-amended media grew as well as or better than those in peat-amended media, regardless of the species grown. Lilac plants in 25% compost produced almost double the amount of shoot dry weight and were 80% taller than plants in the bark: sand or 25% peat media. Maple plants in 50% compost produced at least 33% more shoot dry weight than those in either peat-amended medium. Plum cuttings in 25% compost grew at least 53% taller than those in either peat-amended medium. These results demonstrated that composted paper sludge from newsprint production was a worthy substitute for peat moss in a container medium for the three species tested.
Cold Hardiness of Flowering Crabapple Cultivars
Authors: McNamara Steve , Pellett Harold
Published: August 2020

Stem cold hardiness of 38 crabapple taxa (Malus L.) was evaluated on 6 dates throughout the dormant period of 1992–93. Differences in cold hardiness among taxa were detected on all sampling dates, with no single cultivar being consistently most hardy. Midwinter hardiness levels ranged from −32C (−26F) for ‘Jewelberry’ to −44C (−47F) for M. baccata ‘Jackii’. ‘Dolgo’, ‘Red Jade’, ‘Red Splendor’, ‘Selkirk’, and M. baccata ‘Jackii’ were all hardy to at least −40C (−40F) in midwinter and also exhibited excellent early-and late-season hardiness. Large differences in hardiness among crabapple taxa were observed on November 9 and April 26 sampling dates [14C (25F) and 17C (31F), respectively], indicating that taxa vary substantially in timing and/or rates of acclimation and deacclimation. Although most cultivars demonstrated adequate hardiness for use in USDA hardiness zone 4a, the acclimation and deacclimation characteristics of some taxa may predispose them to injury from extreme low temperatures in the fall and early spring.
Rooting and Subsequent Overwinter Survival of Stem Cuttings of Stewartia ovata
Authors: Curtis David L. , Ranney Thomas G. , Blazich Frank A. , Whitman Everett P.
Published: August 2020

Three experiments were conducted using stem cuttings of Stewartia ovata (Cav.) Weatherby to evaluate: 1) effects of indolebutyric acid (IBA) concentration on percent rooting and rooting index (root system size), 2) influence of N rate and medium amendments (dolomitic lime and/or complete fertilizer) on budbreak prior to overwintering and survival and shoot growth of cuttings following overwintering, and 3) effects of chilling duration on overwinter survival and subsequent shoot growth. Softwood cuttings of S. ovata were taken on June 19 and July 23, 1992, and treated with 0, 1000, 2000, 4000, or 8000 ppm IBA in 50% isopropyl alcohol. Rooting percentages and rooting index were highest for cuttings taken in June and treated with 2000 or 4000 ppm IBA. In the second experiment, cuttings were rooted in pine bark containing three different amendment combinations, and fertilized weekly with either 0, 50, 100, or 200 ppm N following root initiation. Overwinter survival was higher for cuttings rooted in pine bark or pine bark amended with lime, but decreased for cuttings in pine bark amended with lime and a complete fertilizer. Increasing N fertilization up to 200 ppm weekly stimulated budbreak prior to overwintering, resulted in greater shoot growth following overwintering, but had no effect on overwintering survival. In the third experiment, rooted cuttings were subjected to 0, 2, 4, 6, 8, or 10 weeks chilling at 6C (43F). Cuttings chilled for 10 weeks had the highest percent budbreak (survival) and greater overall shoot growth over a 12 week forcing period.
Susceptibility of ‘Skyline’ Honeylocust to Cankers Caused by Nectria cinnabarina Influenced by Nursery Field Management System
Authors: Calkins James B. , Swanson Bert T.
Published: August 2020

The influence of five nursery field management treatments including alternative, sustainable practices (ie. companion crops, allelopathic cover crops/mulches) on the incidence of stem cankers caused by Nectria cinnabarina (Tode: Fr.) Fr. on ‘Skyline’ thornless honeylocust (Gleditsia triacanthos L. var. inermis Willd. ‘Skyline’) was monitored in Minnesota. Although considered a stress related disease, field management treatments that reduced tree vigor (ie. growth), decreased susceptibility to attack by N. cinnabarina while treatments which promoted vigorous growth increased susceptibility. The observed vulnerability of honeylocust trees to N. cinnabarina may be related to plant cold hardiness and subsequent winter injury to root and crown tissue as affected by nursery field management treatment. Moisture stress late in the growing season, resulting from root injury during the previous winter, mechanical root injury from cultivation, and high summer soil temperatures may have increased susceptibility to N. cinnabarina for honeylocust trees grown in bare soil field production systems. Moisture stress in late summer may not be reflected in plant growth, but may increase the susceptibility of honeylocust trees to attack by N. cinnabarina.
Propagation of ‘Carolina Sapphire’ Smooth Arizona Cypress by Stem Cuttings: Effects of Growth Stage, Type of Cutting, and IBA Treatment
Authors: Stubbs Hunter L. , Blazich Frank A. , Ranney Thomas G. , Warren Stuart L.
Published: August 2020

Stem cuttings of ‘Carolina Sapphire’ smooth Arizona cypress [Cupressus arizonica var. glabra (Sudw.) Little ‘Carolina Sapphire’] consisting of 30 cm (12 in) terminals or distal [terminal 15 cm (6 in)] and proximal [basal 15 cm (6 in)] halves of 30 cm (12 in) terminals were taken on three dates associated with specific growth stages (semi-hardwood, hardwood, and softwood). Cuttings were treated with indolebutyric acid (IBA) in 50% isopropanol ranging from 0 to 16,000 ppm (1.6%) and placed under intermittent mist. Regardless of cutting type and auxin treatment, cuttings rooted at each growth stage. Overall percent rooting was highest during the hardwood stage (70%), followed by the semi-hardwood stage (44%). Softwood cuttings exhibited the lowest overall rooting (33%). At each growth stage, percent rooting, root count, and root dry weight varied depending on cutting type and IBA treatment. Rooting percentages ≥70% were attained at the semi-hardwood and hardwood growth stages for particular treatment combinations.
Effects of Preemergence-applied Herbicides on Pampas Grass Grown in Containers
Authors: Green James C. , Keever Gary J. , Gilliam Charles H. , Palmer Christine K. , Olive John W. , Joseph Eakes D.
Published: August 2020

Two experiments evaluated the effects of preemergence herbicides on growth of pampas grass [Cortaderia selloana (Schult. and Schult f.) Asch. and Graebn.] applied after transplanting from 72-cell packs into 3.8 liter (#1) containers. Ronstar (oxadiazon) and Regal O-O (oxadiazon + oxyfluorfen) applied at the manufacturers' recommended rates caused little or no injury. Ornamental Weedgrass Control (pendimethalin), Pendulum 2G (pendimethalin), Pendulum 60 WDG (pendimethalin), Surflan 4AS (oryzalin), Rout (oryzalin + oxyfluorfen), and Factor 65 WG (prodiamine) suppressed root development in the upper 5.1 cm (2 in) of the container medium in both experiments. Application of Surflan 4AS resulted in 100% and 70% mortality of plants in the two experiments, respectively. Lodging was greatest with Factor 65 WG (100% and 90% in the two experiments) and Pendulum 60 WDG (50% in both studies). Some lodging occurred with the application of all dinitroaniline herbicides in the two studies.
Estimating the Cost of Producing Container-Grown Landscape Plants with the Assistance of Computer Accounting Software
Authors: Foshee Kenneth H. , House Lisa Offenbach , Phillips Travis D.
Published: August 2020

Procedures and practices for a container nursery record keeping system were developed. The goal of developing this system was to allow for cost allocation to a given group of plants for pricing and planning purposes. To accomplish this, the economic engineering method was employed to develop a model nursery firm where the best proven practices of plant production were utilized. Enterprise budgets were updated and modified to estimate cost of production for container sized #1 woody landscape plants by five plant species. Job-cost accounting procedures were used to allocate annual fixed costs and general overhead expenses. Results revealed that fixed cost per plant represented approximately one-third of total cost per plant for each species and production method. Determination of per-plant costs in trials was important in determining whether the production of a species was profitable. This also aided in establishing selling prices.
Screening Buddleia Cultivars for Acute Ozone Sensitivity
Authors: Findley Douglas A. , Keever Gary J. , Chappelka Arthur H. , Gilliam Charles H. , Joseph Eakes D.
Published: August 2020

Eight cultivars of buddleia were exposed to ozone (O3) concentrations up to 375 ppb for two 4-hour periods on consecutive days in 1995. Visible injury to all cultivars consisted of small, discrete spots, reddish purple in color, on the adaxial leaf surface. Cultivars differed in sensitivity to acute O3 exposure with ‘Empire Blue’ and ‘Opera’ being the most tolerant and ‘Black Knight’, ‘Nanho Blue’, ‘Pink Delight’, and ‘Royal Red’ the most sensitive. Severe injury occurred on the most sensitive cultivars with O3 exposures of 250 or 375 ppb. At the highest O3 concentration, the severity index (SI), an indicator of foliar injury, ranged from 1.3 (less injury) for ‘Opera’ to 4.6 (more injury) for ‘Pink Delight’. An exposure-response study with ‘Black Knight’ resulted in visible injury increasing as both concentration and number of exposures increased, with the most severe injury to plants given the most exposures (5 days) to the highest concentration (375 ppb, SI of 6.3).
Susceptibility of Selected Juniper Cultivars to Cedar-Apple Rust, Kabatina Tip Blight, Cercospora Needle Blight and Botryosphaeria Canker
Authors: Tisserat Ned A. , Pair John C.
Published: August 2020

The susceptibility of 39 juniper (Juniperus L.) cultivars to cedar-apple rust (Gymnosporangium juniperi-virginianae Schwein.), Kabatina tip blight (Kabatina juniperi R. Schneider & Arx), Cercospora needle blight (Cercospora sequoiae Ellis & Everh. var. juniperi Ellis & Everh.), and Botryosphaeria canker (Botryosphaeria stevensii Shoemaker) was studied in field plantings located in Wichita and Manhattan, KS. Cultivars of J. scopulorum Sarg. showed variable susceptibility to cedar-apple rust and most were moderately to highly susceptible to Kabatina tip blight and Cercospora needle blight. Many were also severely damaged by Botryosphaeria canker. Most J. virginiana L. cultivars were susceptible to cedar-apple rust but were more resistant to other disease problems than J. scopulorum. Cultivars of J. chinensis were highly resistant to all four diseases observed in the plantings. Conidia of B. stevensii were primarily collected in spore traps in late May and June, suggesting this is a major period for fungal infection.
Influence of Surflan (Oryzalin) Concentrations in Irrigation Water on Growth and Physiological Processes of Gardenia jasminoides radicans and Pennisetum rupelli
Authors: Bhandary Rajgopal , Whitwell Ted , Briggs Jeanne , Fernandez R. Thomas
Published: August 2020

This study investigated the effect of oryzalin concentrations on growth, CO2 assimilation, stomatal conductance, transpiration and ethylene synthesis in dwarf gardenia and fountain grass (tolerant and sensitive species). The plant species were subjected to irrigation water containing 10 μg/liter, 100 μg/liter and 1000 μg/liter oryzalin. CO2 assimilation, stomatal conductance and transpiration were measured 2 and 4 weeks after treatment initiation, and ethylene evolution was determined at the end of the study. Oryzalin did not affect net CO2 assimilation, stomatal conductance, transpiration or ethylene evolution for dwarf gardenia or fountain grass. Dwarf gardenia shoot and root weights were not affected by oryzalin, but shoot and root weights of fountain grass were reduced by the highest concentration.
Response of Shade Trees Grown in In-ground Containers to Three Container Substrates
Authors: Murray Christine L. , Lumis Glen P. , Chong Calvin
Published: August 2020

Two-year-old branched seedling whips of green ash, Fraxinus pennsylvanica Marsh. and European birch, Betula pendula Roth, were grown for two seasons (1991 and 1992) in 38-liter (# 10) rigid, plastic, in-ground containers in three different substrate treatments: 10%, 50% and 100% soil, containing 10:30:60, 50:30:20, or 100:0:0 of field soil:sphagnum peat:ground pine bark, respectively. Trees were also planted directly into the soil (field-grown) to serve as a baseline control treatment. Top dry mass, trunk diameter and root dry mass in 1991 and 1992 and two size categories of root dry mass (<3 and 3<6 mm) in 1991 were consistently greatest for container-grown trees in the 10% soil treatment and least in the 100% soil treatments. Corresponding results for the 50% soil treatment were intermediate between the other treatments or similar to the 10% soil treatment. In 1991, the top dry mass and trunk diameter of both species grown in containers with 10% soil and in 1992, the top dry mass of ash, in the same treatment, were greater than those of field-grown trees.
Suppression of Seashore Paspalum in Bermudagrass with Herbicides
Authors: Davis Steve D. , Duncan Ronny R. , Jack Johnson B.
Published: August 2020

A mixture of seashore paspalum (Paspalum vaginatum Swartz) with bermudagrass (Cynodon spp.) results in an overall poor quality turf on golf course fairways. A field experiment was conducted at two locations during 1997 in Hawaii to determine if herbicides would control paspalum encroachment without causing undesirable injury to the bermudagrass. Three applications of Asulox (asulam) applied alone at a total rate of 4.4 kg/ha (4.0 lb/A) or with Image (imazaquin) suppressed paspalum ≥97% by 8 weeks after the initial treatment and ≥83% by 10 weeks. The suppression from three applications of Trimec Plus (MSMA + 2,4-D + mecoprop + dicamba) at a total rate of 11.1 kg/ha (9.6 lb/A) was ≥63% at 8 weeks and ≥70% by 10 weeks. Paspalum suppression from an initial application with Trimec Plus followed by two Asulox treatments was not advantageous, compared with three Asulox treatments. Three applications of Trimec Plus suppressed at least 70% paspalum by 10 weeks. The suppression was poor when treated with Ally (metsulfuron) and sequential applications with Surflan (oryzalin) and MSMA. Tifway bermudagrass (C. transvaalensis x C. dactylon) was severely injured when treated with all herbicides except Ally and Surflan plus MSMA. Maximum injury ranged from 40% when treated sequentially with Trimec Plus and Asulox, to 50% when treated with Asulox, 57% when treated with Asulox plus Image, and 91% when treated with Trimec Plus. By 10 weeks, bermudagrass had started to recover but the overall injury ranged from 28% to 40%.
Effects of Mulch Made From Flurprimidol Treated Zinnia, Silver Maple, and White Ash on Growth of Zinnia
Authors: Premachandra Gnanasiri S. , Chaney William R. , Holt Harvey A.
Published: August 2020

Potential for carryover of flurprimidol in mulch derived from landscape plants and trees treated with this tree growth regulator and its effects on plants were investigated. Flurprimidol (Cutless®) was applied as a soil drench to the growing medium of greenhouse grown zinnia (Zinnia elegans Jacq. ‘Scarlet’) at six concentrations ranging from 0.0016 to 5 mg/kg (0.00000003 to 0.0001 oz/lb) and as solid tree implants (0.2 g a.i./cm diameter) (0.018 oz/in) to plantation grown silver maple (Acer saccharinum L.) and white ash (Fraxinus americana L). Shoots of zinnia were collected three weeks after treatment with flurprimidol and the leaves and one-year-old twigs of the two tree species were collected 1, 6, and 18 months after treatment. Tissues were ground into small particles and either mixed with the growing medium or applied to the surface of pots containing zinnia. Low concentrations of flurprimidol (0.0016 to 0.04 mg/kg soil) (0.00000003 to 0.0000006 oz/lb) stimulated the growth of zinnia, whereas higher concentrations (0.2 to 5 mg/kg) (0.000003 to 0.0001 oz/lb) reduced growth when applied either directly to the growing medium or as residue in mulch derived from treated plants. Mulch made from leaf or twig tissues of silver maple 6 and 18 months after treatment with trunk implants and of white ash 18 months after treatment reduced growth of zinnia.
Feeding Responses of Japanese Beetle to Naturally Occurring Metabolites Found in Rosaceous Plants
Authors: Patton Cynthia A. , Ranney Thomas G. , Burton James D. , Walgenbach James F.
Published: August 2020

Endogenous allelochemicals can have a profound influence on host plant resistance to arthropod pests. This study evaluated 22 naturally-occurring compounds found in Rosaceous trees for their influence on feeding of adult Japanese beetles [Popillia japonica (Newman)]. Individual compounds were incorporated into artificial diets at concentrations from 0 to 100 mM. No-choice feeding trials were conducted over 24 hours. Four general trends were recognized among the dose responses: 1) no response: benzaldehyde, calcium oxalate, tannic acid, 2) stimulatory: rutin, 3) optimal peak: benzoic acid, phloridzin, quercetin, catechin, geraniol, arbutin, caffeic acid, chlorogenic acid, and 4) inhibitory: p-coumaric acid, eugenol, amygdalin, phloretin, naringenin, o-coumaric acid, arginine, asparagine, oxalic acid, and gallic acid. These results suggest that variation in chemical constituents and concentrations may have a strong influence on host plant resistance to Japanese beetles among Rosaceous plants.
Retail Garden Outlets: Business Characteristics and Factors Affecting Industry Performance
Authors: Garber M. P. , Bondari K.
Published: August 2020

A survey was conducted of retail garden outlets in Georgia which consisted primarily of traditional garden centers, feed and seed stores, and hardware stores. Plant material, for all types of retail outlets, represented the largest portion of retail sales followed by chemicals and fertilizers. The average annual retail store sales for all products was $344K, with plant material representing $111K. The survey population represented about $47M in retail plant sales and did not include mass merchants or chain garden centers. Individual consumers (87%) were the primary customers as compared to landscapers or other types of customers. Most plant material was sourced in-state (67%) and only about 3% was produced by retailers. The primary factors identified as having a potential negative impact on plant material sales were adverse weather (26%), competition from mass merchants (23%) and a slowing economy (22%). Most garden centers are open year round (74.5%) as compared to feed and seed (7.1%) or hardware (16.7%) stores. The most common consumer complaints regarding plant quality were identified. Retailer experience with the Georgia Gold Medal new plant program suggests that these programs can create pull-through sales.
Success Varies when Using Subirrigation Instead of Mist to Root Softwood Cuttings of Woody Taxa
Authors: Aiello Anthony S. , Graves William R.
Published: August 2020

A subirrigation method for rooting softwood cuttings of seven woody taxa was compared to use of intermittent mist. Both methods resulted in >90% rooting of ‘Goldflame’ spirea (Spiraea x bumalda Burv. ‘Goldflame’). Averaged over two dates, >50% of ‘Pioneer’ elm (Ulmus L. ‘Pioneer’) cuttings rooted, and >70% of cuttings retained leaves and formed callus regardless of method. Subirrigation without mist was unsuccessful for rooting Lamarck serviceberry (Amelanchier lamarckii F.G. Schroed.), Amur maackia (Maackia amurensis Rupr. & Maxim.), or ‘Kwanzan’ cherry (Prunus serrulata Lindl. ‘Kwanzan’). Subirrigating cuttings without mist resulted in reductions in rooting percentage, leaf retention, and callus formation of >90% for Lamarck serviceberry and >50% for ‘Kwanzan’ cherry compared to misted cuttings. For misted cuttings of Amur maackia, percentage rooting, leaf retention, and callus formation were 23, 48, and 35%, respectively; in contrast, no subirrigated cuttings of Amur maackia survived. ‘Charles Joly’ and ‘Michael Buchner’ lilacs (Syringa vulgaris L. ‘Charles Joly’ and ‘Michael Buchner’) varied in response to the propagation methods. Sixty-one, 15, and 42% of ‘Charles Joly’ lilac cuttings rooted when misted, when subirrigated with tap water, and when subirrigated with a solution of complete fertilizer that contained N at 5.4 mM (75 ppm), respectively. For ‘Michael Buchner’ lilac, 48, 7, and 19% cuttings rooted under mist, when subirrigated with water, and when subirrigated with fertilizer, respectively. We recommend use of subirrigation without mist for rooting softwood cuttings of ‘Goldflame’ spirea, ‘Pioneer’ elm, and ‘Charles Joly’ lilac.
Multiple Pot Box for Container Plant Production
Authors: Haman D. Z. , Yeager T. H. , Beeson R. C. , Knox G.W.
Published: August 2020

Viburnum odoratissimum (Ker-Gawl.) plants were grown for 15 weeks in 3-liter (#1) containers in black multipot boxes that contained a water reservoir and in a conventionally spaced system on black polypropylene. Irrigation events were based on plants in multipot boxes which resulted in under-watering of plants in conventionally spaced containers. Plants grown in the multipot box production system had higher shoot and root dry weights as compared to plants grown in conventionally spaced containers, and their growth indices of the plants in multipot boxes increased at a greater rate than that of plants from the conventional system. Approximately 210 mm (8.3 in) of overhead irrigation was applied during the experiment, in addition to 340 mm (13.3 in) of rain.
Are Ornamental Grasses Acceptable Alternatives For Low Maintenance Landscapes?
Authors: Wolfe June , Zajicek J.M.
Published: August 2020

A survey instrument was designed to determine public perception of selected landscape (ornamental) grass species, the use of grasses in public landscapes, and the importance of research on the water consumption. Results from the survey indicate that 90% of the respondents felt that grasses have landscape (ornamental) value, and 96% felt that municipalities should utilize these plant materials in public landscapes. In addition, 92% of the respondents deemed research on the water conserving abilities of landscape grasses important and 96% would use them if they helped conserve water. When specific grass species were rated for preference by the respondents, statistical differences were noted between the two field sites, survey dates, and desirability of individual species. Grasses located at the site where plants were allowed a longer establishment period had significantly higher visual rankings. Summer visual ratings of grasses were significantly higher than fall ratings. Native Texas and introduced species were rated equally in desirability. Overall the most popular species was Purple Fountaingrass (Pennisetum macrostachyum) with 96% of survey participants agreeing or strongly agreeing that they would use it in their personal landscape. Big Bluestem (Andropogon gerardii) was the least popular species with only a 46% positive rating.
Relative Susceptibility of Cultivars of Flowering Crabapples, Lindens, and Roses to Defoliation by Japanese Beetles
Authors: Potter Daniel A. , Spicer Patricia G. , Held David , McNiel R.E.
Published: August 2020

Relative resistance to defoliation by Japanese beetles (Popillia japonica Newman) was compared among 28 cultivars of flowering crabapples (Malus spp.), 8 species and cultivars of lindens (Tilia spp.), and 53 cultivars of hybrid tea, floribunda, and grandiflora roses (Rosa spp.) in multi-year field evaluations in central Kentucky. Defoliation of crabapples ranged from >95% to <10% among cultivars at the same site, with cultivars ‘Jewelberry’, ‘Louisa’, Malus baccata ‘Jackii’, and ‘Harvest Gold’ having greatest resistance. All lindens were severely damaged in years with heavy beetle flight, but Tilia americana ‘Legend’ and T. tomentosa ‘Sterling’ were less damaged than the others in years with moderate beetle pressure. When beetles were abundant, all rose cultivars were severely defoliated regardless of bloom color. Under more moderate beetle pressure, however, ‘Milestone’, ‘Dynasty’, and ‘Headliner’ hybrid tea roses sustained less damage than others. Damage among individual plants within cultivars often varied widely on a given date, reflecting the beetles' tendency to aggregate on foliage with prior feeding damage.
Effects of Dolomitic Lime on Growth and Nutrient Uptake of Buddleia davidii ‘Royal Red’ Grown in Pine Bark
Authors: Gillman Jeffrey H. , Dirr Michael A. , Kristine Braman S.
Published: August 2020

Buddleia davidii Franch. ‘Royal Red’ was grown in pine bark amended with 0.0, 2.4, 4.7 or 9.5 kg/m3 (0.0, 4.0, 8.0, or 16.0 lbs/yd3) dolomitic lime. Growth characteristics responded quadratically to dolomitic lime with those plants receiving 2.4 kg/m3 having the greatest shoot and root dry weights and inflorescence numbers. Plants grown in 4.7 kg/m3 had the greatest shoot lengths. Concentrations of Ca and Mg in leaves of plants grown in containers without dolomitic lime amendment were below that recommended for normal growth of B. davidii. Leaf concentrations of N, S and Mn showed quadratic responses to dolomitic lime additions. Media pH and concentrations of NO3, Al, B, Mn and P also showed quadratic responses. Media Zn concentrations showed a linear response. Although all dolomitic lime amendments tested improved growth of Buddleia davidii ‘Royal Red’, the incorporation of 2.4 kg/m3 produced maximum growth and inflorescence quantity.
Comparison of Conventional and Alternative Nursery Field Management Systems: Soil Physical Properties
Authors: Calkins James B. , Swanson Bert T.
Published: August 2020

Effects of five nursery field management systems on the physical properties of a Waukegan silt loam soil were investigated: cultivation, herbicide management (oxadiazon), legume companion crop—‘Norcen’ bird's-foot trefoil (Lotus corniculatus ‘Norcen’), winter cereal cover crop/mulch—‘Wheeler’ winter rye (Secale cereale ‘Wheeler’), and mixed grass sod—80% ‘Eton’ perennial ryegrass (Lolium perenne ‘Eton’) and 20% ‘Ruby’ red fescue (Festuca rubra ‘Ruby’). Six tree species were included in the study: Fraxinus pennsylvanica ‘Marshall Seedless’, Malus ‘Red Splendor’, Gleditsia triacanthos var. inermis ‘Skyline’, Acer rubrum ‘Northwood’, Thuja occidentalis ‘Techny’ and Picea glauca var. densata. Field management treatment effects on soil water infiltration capacity, aggregation, bulk density, and temperature were quantified. Significant treatment differences were observed for all soil characteristics investigated. Bare soil treatments (cultivation and herbicide management) generally reduced water infiltration, soil aggregation, and winter soil temperatures and increased bulk density and summer soil temperatures compared to cover crop treatments. After seven years, water infiltration was increased 2 to 4 times for the bird's-foot trefoil companion crop, 3 to 6 times for the rye cover crop/mulch, and 4 to 9 times for the grass companion crop compared to cultivated and herbicide management treatments. Under herbicide management, bulk density of surface soil was increased by 19.7% compared to cultivation. Bulk densities of compacted soil layers just below the depth of cultivation were reduced by 6.6% when maintained with rye and grass cover/companion crops for seven years. Soil aggregation was dramatically reduced by herbicide management and increased for soil maintained under grass sod; only 17.1% of soil aggregates measured 2.0 mm while 72.7% measured 0.5 mm for herbicide managed plots compared to 77.0% and 15.5% for soil maintained with a grass companion crop, respectively. Herbicide management was most often associated with negative effects on soil characteristics important to longterm productivity while grass sod and the rye cover crop/mulch system were most beneficial. The effects of cultivation and the bird's-foot trefoil companion crop on soil physical characteristics were intermediate. The bird's-foot trefoil treatment was difficult to manage and tree growth was reduced sufficiently for the trefoil and grass sod treatments to disqualify them as possible alternatives to cultivation or herbicide management. Implications of soil physical characteristics, as influenced by field management practice, regarding plant performance and soil management are discussed.
Differences in Growth of Container-Grown Red Maple Cultivars in Different Hardiness Zones
Authors: Sibley Jeff L. , Ruter John M. , Eakes D. Joseph
Published: August 2020

Growth of eight container-grown red maple cultivars was evaluated at four locations under dissimilar environmental conditions/hardiness zones in Georgia and Alabama for two years. Rooted cuttings and tissue cultured plantlets were planted in #3 (9.1 liter) containers in one location in the same substrate in April 1995. Trees were transported the second week of June to Blairsville, GA; Muscle Shoals, AL; Auburn, AL; and Tifton, GA in USDA hardiness zones 6b, 7a, 8a, and 8a, respectively. Dormant trees were transplanted to #10 (38 liter) containers the second week of December 1995. At the conclusion of the study, December 1996, growth differed by location and cultivar. Height and stem diameter increase, and root and stem dry weights were greatest at the two Alabama locations for most cultivars and were least at the two Georgia locations. Root:shoot ratios were greatest at the two Georgia locations, an indication of increased carbon partitioning of photoassimilates to roots over stems under dryer growing conditions. Irrigation rates and different environmental conditions among locations have a significant impact on growth response of container-grown red maple cultivars.
Irrigation Volume, Application, and Controlled-release Fertilizer II. Effect on Substrate Solution Nutrient Concentration and Water Efficiency in Containerized Plant Production
Authors: Groves Kelly M. , Warren Stuart L. , Bilderback Ted E.
Published: August 2020

Rooted cuttings of Cotoneaster dammeri Schneid ‘Skogholm’ and seedlings of Rudbeckia fulgida Ait. ‘Goldsturm’ were potted into 3.8 liter (4 qt) containers in a pine bark:sand (8:1 by vol) substrate incorporated with 3.5 g (0.12 oz) N per container provided by one of the following five controlled-release fertilizers (CRFs): Meister 21N–3.5P–11.1K (21–7–14), Osmocote 24N–2.0P–5.6K (24–4–7), Scotts 23N–2.0P–6.4K (23–4–8), Sustane 5N–0.9P–3.3K (5–2–4) or Woodace 21N–3.0P–9.5K (21–6–12). Two hundred ml (0.3 in), 400 ml (0.6 in), 800 ml (1.1 in) or 1200 ml (1.7 in) of water was applied once daily (single) or in two equal applications with a 2 hr interval between applications (cyclic). Substrate solutions were collected from containers of cotoneaster 15, 32, 45, 60, 74, 90, 105, and 119 days after initiation (DAI). Irrigation efficiency [(water applied − water leached) ÷ water applied] was determined on the same days. Cyclic application improved irrigation efficiency at 800 ml (1.1 in) and 1200 ml (1.7 in) ≈ 27% compared to a single application. Irrigation efficiencies averaged over the season were 95%, 84%, 62%, and 48% for cotoneaster and 100%, 90%, 72%, and 51% for rudbeckia at 200 ml (0.3 in), 400 ml (0.6 in), 800 ml (1.1 in) and 1200 ml (1.7 in), respectively. NH4-N and NO3-N and PO4-P concentrations in substrate solution decreased with increasing irrigation volume regardless of CRF. Substrate NH4-N concentration decreased throughout the season with most CRFs below 5 mg/liter by 90 DAI. CRFs mainly affected substrate NH4-N and NO3-N concentrations when irrigated with 200 ml (0.3 in) or 400 ml (0.6 in). Substrate NH4-N, NO3-N, and PO4-P solution concentrations were similar for all CRFs at irrigation volume of 1200 ml (1.7 in). Osmocote, Scotts, and Woodace maintained relatively constant substrate solution levels of PO4-P through 60 DAI. By 90 DAI, substrate PO4-P levels were similar regardless of irrigation volume or CRF. Substrate PO4-P concentrations were never in the recommended range of 5 to 10 mg/liter when irrigated with 800 ml (1.1 in) or 1200 ml (1.7 in) regardless of CRF. Solution pH remained in the recommended range of 5.0 to 6.0 for all irrigation volumes and CRFs throughout the entire study with the exception of Sustane.
Garden Writers Plan to Write About
Authors: Garber M.P. , Bondari K.
Published: August 2020

The five categories of plants projected by members of the Garden Writers Association of America (GWAA) to have the greatest future demand were herbaceous perennials, native ferns and wildflowers, ornamental grasses, herbs, and ground covers. This survey noted that the two most important plant traits likely to affect future demand are multi-seasonal color/interest and pest resistance/tolerance. In preparation of gardening communications about plants, the most valued sources of information were personal growing experience, readily available information, and success stories from the local arboreta/botanical garden. The type of plant material information most valued by Garden Writers was regional suitability, landscape requirements, and flowering habit.
Growth of Dracaena marginata and Spathiphyllum ‘Petite’ in Sphagnum Peat- and Coconut Coir Dust-based Growing Media
Authors: Stamps Robert H. , Evans Michael R.
Published: August 2020

A comparison was made of Canadian sphagnum peat (SP) and Philippine coconut (Cocos nucifera L.) coir dust (CD) as growing media components for greenhouse production of Dracaena marginata Bak. and Spathiphyllum Schott ‘Petite’. Three soilless foliage plant growing mixes (Cornell, Hybrid, University of Florida #2 [UF-2]) were prepared using either SP or CD and pine bark (PB), vermiculite (V), and/or perlite (P) in the following ratios (% by vol): Cornell = 50 CD or SP:25 V:25 P, Hybrid = 40 CD or SP:30 V:30 PB, UF-2 = 50 CD or SP: 50 PB. Dracaena root growth was not affected by treatments but there were significant mix × media component interactions that affected plant top growth parameters. In general, the growth and quality of D. marginata were reduced by using CD in Cornell, had no effect in Hybrid, and increased in UF-2. S. ‘Petite’ grew equally well in all growing mixes regardless of whether CD or SP was used; however, plants grew more in Cornell and Hybrid than in UF-2. S. ‘Petite’ roots, which were infested with Cylindrocladium spathiphylli, had higher grades when grown in CD than when the media contained SP.
Effects of Varying Water Quality on Growth and Appearance of Landscape Plants
Authors: Quist Tanya M. , Williams C. Frank , Robinson M. L.
Published: August 2020

Increasing demand for limited water supplies in populated arid regions over the next decade may require implementation of new water-use practices. Eliminating use of high-quality water for landscape irrigation by using low-quality water delivered through secondary systems is an ideal option for conserving potable water. However, irrigation of woody landscape plants using waters high in inorganic salts may adversely affect soil fertility, structure, plant growth and appearance. Twelve woody ornamentals commonly used in landscapes in Salt Lake County, Utah, were treated with three blends of Utah Lake and Provo River water to assess the quality of plants produced.

Three irrigation treatments, designated high-, medium-, and low-quality water were blended to maintain sodium concentrations of 15, 80 and 120 mg/liter respectively. Soils irrigated with medium-and low-quality water developed significantly higher adjusted sodium absorption ratio (SAR) and salinity than soils irrigated with high quality water and the effect varied with time. Except for four species, medium-and low-quality water did not significantly lower scores for plant appearance. Results of this two-year study support development of secondary water systems and use of lower-quality water for landscape irrigation.
Effect of Supplemental Nitrogen Fertilization on the Movement and Injury of Azalea Lace Bug (Stephanitis pyrioides(Scott)) to Container-grown Azaleas
Authors: Casey Christine A. , Raupp Michael J.
Published: August 2020

Certain arthropods feed selectively and perform better on plants and plant tissues with elevated levels of nitrogen. Yet it is a common practice to use supplemental nitrogen in the production and maintenance of woody landscape plants. The link between elevated nitrogen levels and improved performance of herbivorous arthropods is particularly strong for sap suckers in the order Heteroptera, the majority of which are phloem feeders. There have been no studies to date on the effects of fertilization of woody plants on important mesophyll-feeding Heteroptera, such as azalea lace bug.

We examined the relationship between the movement and injury of azalea lace bug and levels of fertilization of azaleas. The objective of this study was to determine if this insect responded to supplemental nitrogen fertilization in a way similar to many phloem-feeding Heteroptera and mesophyll-feeding Acarina. In these taxa, numerous studies documented improved performance and increased host plant injury as a result of supplemental nitrogen fertilization. We measured injury and colonization by azalea lace bug of azaleas receiving four levels of nitrogen fertilization. Plants with elevated nitrogen levels were preferentially chosen by azalea lace bug but did not exhibit greater levels of leaf injury.
Sequential Postemergence/Preemergence Treatments for Crabgrass Control in Bermudagrass Turf
Authors: Wiecko Greg , Couillard Andree-Anne
Published: August 2020

Crabgrass (Digitaria spp.) was controlled in common bermudagrass [Cynodon dactylon (L.) Pers.] with postemergence (POST) and preemergence (PRE) herbicides on a tropical island of Guam. The recommended label rates of PRE herbicides oxadiazon at 3.4 kg/ha (3.0 lb/A), pendimethalin at 3.4 kg/ha (3.0 lb/A), and dithiopyr at 0.6 kg/ha (0.5 lb/A) were applied initially and one-half recommended rates were applied to one-half of the plots 8 weeks later. MSMA was applied as the POST herbicide treatment in 1, 2, or 3 applications. The first MSMA treatment was applied in sequence with the PRE herbicides and followed by either 1 or 2 additional MSMA applications at 1 or 1 and 2 weeks after the initial MSMA application. Two weekly applications of MSMA assured complete control of existing crabgrass. Single applications of pendimethalin, oxadiazon, and dithiopyr at full rates assured ≥90% control for a period of 20 to 26 weeks during the rainy season and for 6 to 12 weeks during the dry season. There was no advantage of the second PRE treatments at a reduced rate. On fairways where crabgrass infestation was 95%, an application of MSMA resulted in severe turf discoloration lasting 5–6 weeks.
Effects of Pruning Liriope Bibs During Division on Subsequent Growth
Authors: Hayes Christine K. , Gilliam Charles H. , Keever Gary J. , Eakes D. Joseph
Published: August 2020

Three experiments were conducted to determine if shoot pruning of liriope [Liriope muscari (Decne.) L.H. Bailey ‘Big Blue’, ‘Evergreen Giant’, and ‘Variegata’] at division affected subsequent growth of roots and shoots. Plants were divided into single bibs and shoots were either left unpruned or pruned 5 cm (2 in) above the plant crown. Plants with shoots pruned took longer to develop 25 new root tips and had smaller root masses at the end of the experiment. ‘Big Blue’ plants had 7.5 bibs per container when plants were not pruned and 4.2 bibs per container when plants were pruned. Root system number at division was also evaluated. Plants with larger roots systems (10 or more roots) developed 25 new roots faster, and produced more bibs than plants with smaller root systems (3-5 roots) at division. In experiments 2 and 3, ‘Evergreen Giant’ was similar to ‘Big Blue’ in that plants that were not pruned developed 25 new roots faster and had larger root systems at the end of the experiment than plants that were pruned. Results with ‘Variegata’, known to be a slower growing cultivar, were varied.
Whitefly and Lace Bug Performance on Lantana spp. Cultivars in the Greenhouse
Authors: Townsend Monica L. , Oetting Ronald D. , Braman S. Kristine
Published: August 2020

Performance of greenhouse whitefly, silverleaf whitefly, and lantana lace bug for eleven cultivars of Lantana spp. was assessed in greenhouse experiments. Insect population growth was monitored for seven weeks in three experiments. Relative damage at three weeks post-infestation with lantana lace bug was also evaluated. All cultivars supported growth and development of all insect species evaluated. Initial population development occurred differentially on cultivars with larger leaves, e.g., ‘Miss Huff’ and ‘Confetti’. However, by week seven all cultivars supported high populations of greenhouse and silverleaf whitefly and lantana lace bug.