bluuebunny/crossref_metadata_2025 huggingface dataset:
Root and Shoot Growth Periodicity of Pot-in-Pot Red and Sugar Maple
Authors: Harris J. Roger , Fanelli Jody
Published: August 2020

Red maple (Acer rubrum L. ‘Franksred’) and sugar maple (Acer saccharum Marsh. ‘Green Mountain’) trees were grown in a 56 liter (15 gal) pot-in-pot system for two years. During the second year of production, root growth was observed through observation plates fitted into the container sidewalls, and shoot extension was periodically measured. Root growth began in early March, approximately one month before budbreak for both species. Root growth dramatically slowed down at the onset of budbreak, but quickly resumed and was concurrent with shoot elongation. Root growth slowed dramatically in the fall when substrate temperatures dropped to 5–7C (40–45F). Root growth stopped during the winter for red maple, but some nominal root growth continued throughout the winter for sugar maple. Red maples had over 5 times more total root length against observation plates at the end of the experiment than sugar maples.
Seedling Growth of Atlantic White-Cedar as Influenced by Photoperiod and Day/Night Temperature
Authors: Jull Laura G. , Blazich Frank A. , Hinesley L. Eric
Published: August 2020

Seedlings of Atlantic white-cedar [Chamaecyparis thyoides (L.) B. S. P.] were grown in controlled-environment chambers for 12 weeks under short-or long-day conditions with 9-hr days at 18, 22, 26 or 30C (64, 72, 79 or 86F) in factorial combination with 15-hr nights at 14, 18, 22 or 26C (57, 64, 72 or 79F). Dry matter production was influenced by photoperiod and day/night temperature. For all day temperature × photoperiod interactions, except root:shoot ratio, growth was highest under long days. Day × night temperature interactions occurred for all growth measurements except root dry weight. Root dry weight was highest at 30/22C (86/72F); top (shoot) dry weight at 26/22C (79/72F). Nights of 14C (57F) resulted in the lowest top dry weight. Total plant dry weight was highest at nights of 22C (72F) for all day temperatures. At days of 30C (86F), total plant dry weight was highest with nights ≤ 22C (72F); however, data for 30/22C (86/72F) and 26/22C (79/72F) were similar. The highest root: shoot ratio occurred at nights of 14C (57F) with days ≤ 26C (79F). Mean relative growth rate was highest at nights of 22C (72F) with days of 26C (79F) or 30C (86F). Maximum stem caliper occurred at days of 22C (72F) with nights ≥ 18C (64F). Height and crown width were highest at 26/22C (79/72F). A day/night cycle of 30/22C (86/72F) with long days was optimal for seedling growth.
Miscanthus Anderss. Produces Viable Seed in Four USDA Hardiness Zones
Authors: Meyer Mary Hockenberry , Tchida Courtney L.
Published: August 2020

Forty-one taxa of Miscanthus grown in USDA Hardiness Zones 4, 5, 6, and 7 were examined in 1996 and 1997 for seed set and viability. Although laboratory results varied widely between years, climatic zones, and cultivars, many plants set viable seed. Eleven types had <18% viable seed, including ‘Morning Light’, ‘Variegatus’ and ‘Zebrinus’, and appear to represent the least risk for becoming invasive plants, especially in northern climates. Other characteristics of Miscanthus are discussed in terms of invasive potential in the United States.
Growth Periodicity for Container-Grown Red and Freeman Maple Cultivars in AHS Heat-Zone 8
Authors: Sibley Jeff L. , Ruter John M. , Eakes D. Joseph
Published: August 2020

Growth patterns of seven red maple (Acer rubrum L.) and three Freeman maple (Acer x freemanii E. Murray) cultivars grown in containers in Alabama were evaluated using monthly destructive harvests. The effectiveness of a growth modeling technique not previously described is demonstrated using the data presented for both the Freeman maple (red maple xsilver maple interspecific cross) and red maple categories. Freeman maple cultivars ‘Armstrong’, ‘Celzam’ (Celebration™), and ‘Jeffersred’ (Autumn Blaze™); and red maple cultivars ‘Autumn Flame’, ‘Fairview Flame’, ‘Landsburg’ (Firedance™), ‘Franksred’ (Red Sunset™), ‘Olson’ (Northfire™), ‘Northwood’, and ‘October Glory®’ were studied. Uniform liners of each cultivar were planted in 9.1-liter (#3) containers in March 1996. More than 75% of seasonal height and diameter growth was complete for most cultivars before mid-August, while only 25% of root growth had occurred by the end of August. The remaining 75% of root growth occurred from August through November. The greatest overall growth (based on height, diameter, and root growth increase) was for ‘Autumn Flame’ and ‘October Glory®’, both red maple cultivars; and Freeman maple cultivars ‘Celzam’ and ‘Jeffersred’. The least overall growth (based on height, diameter, and root growth increase), was for red maple cultivars ‘Northwood’ and ‘Landsburg’.
Comparison of Perlite and Peat:perlite Rooting Media for Rooting Softwood Stem Cuttings in a Subirrigation System with Minimal Mist
Authors: Giroux Gregory J. , Maynard Brian K. , Johnson William A.
Published: August 2020

Perlite and mixtures of milled sphagnum peat and perlite (1:16, 1:8, and 1:4 by vol) were compared as rooting media in a propagation system utilizing subirrigation with minimal mist for rooting softwood stem cuttings of nine woody plant species. The influence of rooting medium on percentage rooting, number of roots per rooted cutting, and length of the longest roots on each cutting varied with species. Composition of the media had no effect on percentage of cuttings that rooted, number of roots per rooted cutting, or length of the longest root of ‘Late Blue’ highbush blueberry (Vaccinium corymbosum L. ‘Late Blue’). Cuttings of Amur maple (Acer ginnala Maxim.) and ‘Ruby Spice’ sweet pepper bush (Clethra alnifolia L. ‘Ruby Spice’) produced the longest root in 1:4 peat:perlite, and cuttings of ‘Ruby Spice’ sweet pepper bush produced the greatest number of roots in 1:8 peat: perlite. Cuttings of redvein enkianthus [Enkianthus campanulatus (Miq.) Nichols] produced more roots in 1:8 peat:perlite than in perlite, and longer roots in 1:16 and 1:8 peat: perlite than in perlite. The number of roots per cutting of ginkgo (Ginkgo biloba L.) was greatest in 1:16 peat: perlite. Cuttings of Carolina silverbell (Halesia carolina L.) rooted in the greatest percentage in perlite, and cuttings of panicle hydrangea (Hydrangea paniculata Sieb.) rooted in the greatest percentages in perlite and 1:8 peat: perlite. The number of roots per cutting of ‘Kwanzan’ cherry and ‘Shasta’ doublefile viburnum [Viburnum plicatum Thunb.var. tomentosum (Thunb.) Rehd. ‘Shasta’] was greatest in 1:16 and 1:8 peat: perlite. Root length per cutting of ‘Kwanzan’ cherry (Prunus serrulata Lindl. ‘Kwanzan’) increased with an increase in the amount of peat in the medium. Rooting medium pH decreased and moisture content increased as the amount of peat in the media increased from 1:16 to 1:8 to 1:4 (peat:perlite, by vol).
Mulches and Subirrigation Control Weeds in Container Production
Authors: Wilen Cheryl A. , Schuch Ursula K. , Elmore Clyde L.
Published: August 2020

Weed control efficacy of organic mulches as well as a copper hydroxide-coated geotextile (fabric) disk was examined using Rhaphiolepis indica L. or Callistemon citrinus [(Curtis) Stapf] growing in containers. Rout (oxyfluorfen plus oryzalin) and corn gluten meal were included as herbicide treatments. In a second experiment, the effect of subirrigation versus surface irrigation and different depths of pine bark mulch on weed control was studied. In the mulch/herbicide studies, all of the mulch treatments, including the geotextile disk, provided broadleaf weed control, but not annual bluegrass control, similar to that of Rout. Broadleaf weeds were not controlled by corn gluten meal. Although though the number of grass seedlings was reduced 49% from that of the control, Rout reduced the number by 89%. In the mulch depth/irrigation study, mulching reduced weed weight by 92% over that of the control (no mulch and surface irrigated) 8 weeks after transplanting. Subirrigation reduced the number of weeds by at least 95% over that of the control.
Seed Germination of Rhododendron chapmanii: Influence of Light and Temperature
Authors: Arocha Luis O. , Blazich Frank A. , Warren Stuart L. , Thetford Mack , Berry James B.
Published: August 2020

Seeds of Rhododendron chapmanii A. Gray (Chapman's rhododendron) were germinated at 25C (77F) or 8/16 hr thermoperiods of 25/15C (77/59F) or 30/20C (86/68F) with daily photoperiods of 0 (total darkness), ¼, ½, 1, 2, 4, 8, 12 or 24 hr. For all temperatures, no germination occurred during a 30-day period for seeds not subjected to light. At 25C (77F) germination was a function of photoperiod. The longer the photoperiod the greater the germination with 30-day germination ≥90% for photoperiods ≥8 hr. Alternating temperatures, particularly 25/15C (77/59F), enhanced germination when light was limiting. The highest germination (80%) by day 30 for seeds at 30/20C (86/68F) was realized with a 24-hr photoperiod, whereas 30-day germination ≥ 90% occurred at 25/15C (77/59F) and 25C (77F) for photoperiods of 8 and 12 hr and 8, 12, and 24 hr, respectively.
Germination of Japanese Stewartia Seeds: The Effects of Warm and Cold Stratification
Authors: Struve Daniel K. , Oleksak Brian A. , Kawahara Takayuki , Kanazashi Ayako
Published: August 2020

Japanese Stewartia (Stewartia pseudocamellia (Maxim.)) is a species with outstanding landscape qualities, but is not widely available because reliable propagation protocols have not been developed, including procedures for overcoming seed dormancy. Three experiments were conducted to determine the warm and cold stratification requirements of Japanese Stewartia seeds. In the first experiment, seeds given a 3-day aerated water soak in 1 mM GA3, followed by 3 months warm moist stratification at 25C (77F) had greater germination 173 to 297 days after initiation of cold (7C, 45F) stratification than seeds given a 3-day aerated water soak and similar warm and cold stratification treatments. Final germination was 70%, but germination was not synchronous, it occurred over 172 days. In the second experiment, germination was low (less than 1%) for seeds given either 9 months cold moist stratification or 3 months warm moist stratification at 20C (68F) before 6 months cold moist stratification. Seeds given a 3-month warm moist stratification at an alternating 12 hr 20/12C (68/54F) cycles and 10 months cold moist stratification germinated from 30 to 93%, depending on mother tree. Germination was asynchronous, beginning after 150 days cold stratification and continuing for the next 165 days. In the third experiment, germination was not enhanced by a 3-day aerated water soak in either 1 mM GA3 or water, compared with seeds given no aerated water soak prior to cold moist stratification. Germination was greatest, 35%, for seeds given a 3-month warm moist stratification at 15C (59F) followed by at least 4 months cold moist stratification. However, germination was asynchronous. The results begin to identify the warm and cold stratification treatments that result in high germination.
Flood Irrigation of Container-grown Euonymus and Thuja as Affected by Fertilizer Rate and Substrate
Authors: Lumis Glen , Purvis Peter , Taurins Ligita
Published: August 2020

Euonymus fortunei [(Turcz.) Hand.-Mazz.] ‘Emerald Gaiety’ and Thuja occidentalis L. ‘Little Giant’ were grown outdoors in #1 (3 liter) containers for one season on waterproof, crushed stone beds flooded and drained from below the stone. Plants were grown in a bark substrate (2/3 pine bark:1/3 sphagnum peat) or a peat substrate (1/3 pine bark:2/3 sphagnum peat) with either a high or medium rate of incorporated, controlled release fertilizer [17N–2.6P–10K (Sierra 17–6–12)] [6.0 or 4.0 kg/m3 (l0.0 or 6.7 lbs/yd3)]. For both species, the high fertilizer rate resulted in less top dry weight, and higher substrate electrical conductivity (EC) and NO3-N. Foliar N levels were also higher with the higher fertilizer rate. Compared with bark, the peat substrate resulted in less top dry weight of Thuja (not Euonymus) and higher substrate EC, NO3-N and water retention, and foliar N levels. Substrate EC levels in the upper one-third [5 cm (2 in)] of the container were nearly twice those in the lower two-thirds [10 cm (4 in)], reaching 7.1 dS/m with the high fertilizer rate in peat. In comparison to plants under overhead irrigation (high fertilizer rate only), flooded plants grew as much as (Euonymus) or more (Thuja) in the bark substrate but both species grew less in the peat. Substrate EC and NO3-N with flood were either similar or lower in bark, but similar or higher in peat compared to overhead. The amount of roots and their distribution appeared similar for both types of irrigation.
Ornamental Grass Growth Response to Three Shade Intensities
Authors: Cole James T. , Cole Janet C.
Published: August 2020

Growth of perennial quaking grass (Briza media L.), ‘Red Baron’ Japanese bloodgrass (Imperata cylindrica (L.) Beauv. ‘Red Baron’), river oats (Chasmanthium latifolium (Michx.) Yates), ‘Hameln’ dwarf fountain grass (Pennisetum alopecuroides (L.) Spreng. ‘Hameln’), and ‘Big Blue’ monkeygrass (Lirope muscari (Decne.) L.H. Bail. ‘Big Blue’) in 0%, 30%, or 60% shade was evaluated in container and in-ground experiments conducted over two growing seasons. Shade intensity did not affect plant height of any species grown in containers in 1997 or those grown in the ground that were planted and harvested in 1998. In 1997, width of containerized perennial quaking grass increased and width of containerized dwarf fountain grass decreased with increasing shade. In 1998, width of containerized Japanese bloodgrass increased and width of containerized dwarf fountain grass decreased with increased shade. Container-grown river oats shoot and root dry weight increased with shade intensity in 1998. Root to shoot (R/S) ratio decreased linearly with shade intensity for containerized river oats in 1997. Height of in-ground Japanese bloodgrass was not affected by shade intensity at any harvest time; however, height of perennial quaking grass increased and height of river oats and monkeygrass decreased as shade intensity increased regardless of harvest time. Few differences in plant width among shade treatments occurred for in-ground plants. Shoot dry weights for in-ground plants generally decreased with increasing shade intensity. Climatic differences may account for the variability in plant growth between the two years of the study.
Evaluation of Bedding Plant Varieties for Resistance to Phytophthora
Authors: Banko Thomas J. , Stefani Marcia A.
Published: August 2020

Seedlings of several annual and perennial bedding plant species were inoculated with an isolate of Phytophthora nicotianae (synonym = P. parasitica) and planted into field beds in a simulated landscape situation. Throughout the growing season, growth measurements and disease ratings of the inoculated plants were compared with those of non-inoculated control plants of the same species in identical beds. Phytophthora-inoculated plants that continued to thrive through most of the growing season included Ageratum houstonianum, Celosia ‘Apricot Brandy’, and ‘New Look’; Dahlia ‘Harlequin’; Eustoma grandiflorum (prairie gentian); Lobularia ‘Carpet of Snow’; Nicotiana ‘Alta Dwarf White’, ‘Domino Salmon’, and ‘Nicki Red’; Pelargonium (geranium) ‘Multibloom Scarlet Eye’; Petunia ‘Polo Salmon’, and ‘Sugar Daddy’; Portulaca ‘Sundial Peppermint’; Rudbeckia ‘Rustic Dwarf’; Salvia ‘Lady in Red’, and ‘Victoria Blue’; Tagetes (marigold) ‘Disco Mix’, ‘Inca Orange’, ‘Inca Yellow’, ‘Janie Harmony Improved’, and ‘Gold Fireworks’; and Zinnia angustifolia. Plants that performed poorly following inoculation with Phytophthora include Antirrhinum (snapdragon) ‘Liberty White’, and ‘Liberty Mix’; Catharanthus (vinca) ‘Little Bright Eye’, and ‘Tropicana Rose’; Hibiscus ‘Disco Belle Mix’; Impatiens ‘Accent Bright Eye’; Leucanthemum x ‘Alaska’; Melampodium ‘Medallion’; Salvia ‘Turkestanica’; Torenia ‘Clown Mix’; Verbena ‘Imagination’; and Viola (pansy) ‘Fama See Me’. This study identifies bedding plant taxa which will provide an acceptable display in landscape beds infested with Phytopthora nicotianae (synonym = P. parasitica).
Consumer Perceptions of Product and Service Quality Attributes in Six U.S. States
Authors: Behe Bridget , Barton Susan
Published: August 2020

Of seven dimensions contributing to garden center quality, customers ranked plant quality as the most important dimension (30%) and responsiveness and assurance as half as important (15%); the other dimensions (tangibles, reliability, empathy, quality of non-plant products) were slightly less important (10%). Plant health and condition (32%) was the most important plant or product characteristic, followed by price (22%) and assortment and variety (21%). Large gaps between customer expectations and perceptions existed for ‘clearly marking plant price’ (0.9), ‘willingness to offer guarantees’ (0.8), ‘plant health’ and ‘name labeling’ (0.7). Service quality gaps were reported for the tangibles dimension in the range of 0 to −0.29 and in the other four dimensions (reliability, empathy, responsiveness and assurance) in the range of −0.30 to −0.59. More frequent purchasers (Buyer 3—people who made more than 10 purchases from surveyed outlets) purchased over two-thirds of their plants from the survey outlet and had higher reliability perceptions as compared to less frequent purchasers (Buyers 1 and 2). When respondents were categorized by their expenditure at the survey outlet, those with lower expenditures ($1–50) had lower perceptions in all five service quality dimensions. Traditional retail customers responded with higher perceptions in all five service quality dimensions than mass merchandiser customers.
Fishwaste Compost Medium Improves Growth and Quality of Container-grown Marigolds and Geraniums Without Leaching
Authors: Hummel R.L. , Kuo S. , Winters D. , Jellum E.J.
Published: August 2020

Utilization of fish waste for producing fishwaste compost (FWC) as a value-added product is preferred to disposing of it in ocean dumping or landfills. This study determined: (i) the effectiveness of FWC as a container-growth medium and N source for greenhouse production of marigolds (Tagetes patula L. ‘Queen Sophia’) and geraniums (Pelargonium x hortorum L.H. Bailey ‘Sprinter Scarlet’) that were drip-irrigated to prevent leaching; and (ii) if leaching was necessary to sustain plant growth. In a 3 by 3 factorial experiment, plants were grown in 100% FWC, 50% FWC:50% Douglas-fir bark (B), and 100% B at 0, 160, and 320 mg (0, 0.0056, 0.0112 oz) N container−1 applied as NH4NO3 every 2 weeks. Under drip irrigation, FWC in the 100% FWC growing medium supplied a sufficient amount of available N up to 7 weeks after transplanting to produce plant quality, shoot growth index (SGI), and shoot and root dry weights comparable to those treated with 320 mg N container−1. In the 50% FWC: 50% B growing medium fertilization with 320 mg N improved plant growth and quality 7 weeks after transplanting. The concentration of inorganic N (NO3 plus NH4) in the 100% FWC declined to very low levels 7 weeks after transplanting. This indicated that FWC used as the sole component of the growing medium was an effective N source for marigolds and geraniums up to 7 weeks after transplant. Compared with no leach plants, irrigation of 100% FWC marigolds with a weekly leaching fraction of about 0.55 did not affect quality, SGI, and shoot dry weight at the time-of-sale, 7 weeks after transplant. The FWC did not have sufficiently high salt content to require minimum leaching to prevent salt injury to the plants.
Response of Five Woody Landscape Plants to Primo and Pruning
Authors: Thetford Mack , Berry James B.
Published: August 2020

The use of Primo (trinexapac-ethyl) was investigated as an alternative to pruning of container-grown woody ornamental species. A foliar spray of 469, 938, or 1407 ppm (0.5, 1.0 or 1.5 oz/gal) was applied to pruned plants. A nontreated control (water) and an industry control [Atrimmec (dikegulac-sodium)] were also included for comparison. Monthly mechanical pruning or no pruning treatments were imposed during the production period. Monthly pruning alone reduced the height of euonymus, forsythia, Chinese privet, waxleaf privet, and azalea. Efficacy of plant growth regulator treatments differed among the five species. Primo was not effective in suppressing the height or trimming dry weight of forsythia, Chinese privet, or waxleaf privet and provided only a transient suppression of euonymus and azalea.
Plant Growth Retardant Application to Achillea x ‘Coronation Gold’ and Gaura lindheimeri ‘Corrie's Gold’
Authors: Burnett Stephanie E. , Keever Gary J. , Gilliam Charles H. , Raymond Kessler J. , Hesselein Charles
Published: August 2020

In two experiments conducted under nursery conditions in 1998 and 1999, the herbaceous perennials, Achillea x ‘Coronation Gold’ and Gaura lindheimeri ‘Corrie's Gold’ were treated with one of four plant growth retardants (PGRs): B-Nine at 2,500, 5,000, or 7,500 ppm; Bonzi at 33, 66, or 99 ppm; Cutless at 50, 100, or 150 ppm; Pistill at 500 or 1,000 ppm; or left untreated. Only Pistill delayed flowering of achillea while Bonzi and Cutless accelerated flowering of achillea. In 1998, B-Nine provided little growth suppression of achillea; however in 1999, when plants were pruned just prior to treatment and thus less reproductively developed, height at the most effective concentration of 7,500 ppm was reduced 33% compared to untreated plants over the duration of the experiment. At the most effective concentration of 99 ppm, Bonzi retarded growth 15% and 31%, over the duration of the experiment, while Cutless at 150 ppm suppressed growth 21% and 46% in 1998 and 1999, respectively, compared to an untreated control. Plants treated with the most effective concentration of Pistill were 13% and 21% shorter than non-treated plants over the duration of the experiment in 1998 and 1999, respectively. However, in 1998 quality ratings of Pistill-treated plants were lower than for control plants, and the duration of control was shorter than with B-Nine, Bonzi, or Cutless in 1999. Only Cutless provided consistent growth suppression of gaura; plants treated with the most effective concentration of 150 ppm were an average of 19% smaller at 60 days after treatment (DAT) in 1998 and 13% smaller than control plants from 28 to 70 DAT in 1999. B-Nine and Pistill provided more transitory control. In 1999, the most effective concentration of B-Nine suppressed growth 9% from 28 to 56 DAT. Plants treated with the most effective concentration of Pistill of 500 ppm averaged 23% smaller at 14 and 28 DAT than control plants. Application of Pistill delayed flowering 11 to 13 days in 1998.
Susceptibility of Crabapple Cultivars to Several Diseases in the Gulf Coast Region of Alabama
Authors: Hagan A. K. , Tilt K. M. , Williams J. D. , Akridge J. R.
Published: August 2020

The occurrence and severity of fireblight (Erwinia amylovora), apple scab (Venturia inequalis), cedar rust diseases (Gymnosporangium sp.), powdery mildew (Podosphaeria leucotricha) and frogeye leaf spot (Botryosphaeria obtusa) were assessed on 60 cultivars of flowering crabapple (Malus sp.) in Brewton, AL (Plant Hardiness Zone 8). Of these diseases, fireblight was the most widespread and damaging over the four-year test period. Noticeable and sometimes damaging levels of frogeye leaf spot and apple scab were seen on a few select crabapple cultivars. Surprisingly, none of the cedar rust diseases commonly found in Alabama on members of the apple family caused significant damage. The signs or symptoms of powdery mildew were never seen on any of the 60 crabapples. Of the crabapple cultivars screened, ‘Eleyi’, ‘Radiant’, ‘Adams’ dwarf, and ‘Velvet Pillar’ had the highest survival rates, as well as resistance to fireblight and frogeye leaf spot. However, ‘Radiant’ and, particularly, ‘Eleyi’ are sensitive to apple scab and may suffer considerable damage in landscape plantings where the climate is cooler. ‘Red Splendor’ dwarf and M. baccata cv. ‘Jackii’ were also highly disease resistant but did not have good rates of survival. Oxysporus root and collar rot (O. latemarginatus) killed many trees and was most prevalent in poorly drained areas found behind several low terraces. On the basis of the high risk of disease and poor overall survival rate, the majority of crabapples tested cannot be considered well adapted to the Gulf Coast region of Alabama nor to adjoining states.
Evaluation of Green Lacewings for Suppressing Azalea Lace Bug Populations in Nurseries
Authors: Shrewsbury Paula M. , Smith-Fiola Deborah C.
Published: August 2020

Greenhouse and nursery studies were conducted to determine an optimal release rate and efficacy of green lacewing (glw) larvae, Chrysoperla carnea (Stephens), for suppression of azalea lace bug (alb), Stephanitis pyrioides (Scott). In a greenhouse study, different densities of lace bugs (40 or 80 per plant) did not influence the percent mortality caused by green lacewings. However, greater numbers of green lacewing larvae released resulted in higher lace bug mortality (5 and 20 glw per plant resulted in an average lace bug mortality of 79% and 97%, respectively). Lacewing larvae released in a production nursery, at rates of 5/plant and 10/plant, and acephate (Orthene) significantly reduced lace bug populations, with green lacewings at 10/plant and acephate reducing lace bug densities more than green lacewings at 5/plant. In a second nursery trial, lacewing larvae released into production blocks of azaleas resulted in a 97% reduction in lace bugs. These studies suggest that augmentative release of green lacewing larvae may provide an alternative control tactic that can be integrated into lace bug pest management programs.
A Shoot-Tip Culture Micropropagation System for Chokecherry
Authors: Zhang Zhen , Dai Wenhao , Cheng Zong-Ming , Walla James A.
Published: August 2020

A micropropagation system was developed to clonally propagate juvenile and mature chokecherry plants. Establishment of shoot tips from seedling plants was best on Murashige and Skoog (MS) medium with 5 μM benzyladenine (BA) and 5 μM indolebutyric acid (IBA). Significantly more shoots proliferated on the MS or Driver and Kuniyuki Walnut (DKW) medium than on Woody Plant medium. Rooting of microshoots could be induced on medium with either IBA or naphthaleneacetic acid (NAA). The highest rooting percentage and the greatest number of roots occurred when shoots were placed in a medium with 0.5 or 2.5 μM IBA. More than 20 chokecherry plants shown to have a high level of field tolerance to X-disease were micropropagated for further X-disease resistance testing using the technique described here.
Tree Seedling Establishment with Protective Shelters and Irrigation Scheduling in Three Naturalized Landscapes in Utah
Authors: Kjelgren Roger , Chapman Neil , Rupp Larry
Published: August 2020

We investigated the effect of irrigation scheduling and tree shelters on survival and growth of nine tree species during first-year establishment in three naturalized Utah landscapes with divergent soil and climate. Seedlings of nine species were planted at high mountain [MTN; 2180 m (7150 ft)], mountain foothills [FTH; 1350 m (4430 ft)], and alkali desert [DES; 1320 m (4330 ft)] sites. Half the trees at each site were enclosed with transluscent plastic shelters after planting, and all trees were irrigated when water loss, estimated from local evapotranspiration, depleted plant-available soil water. Tree condition was rated through the growing season, water potential was measured once in late season to assess plant water status, and the number of surviving trees were counted. Despite irrigation, tree condition at the DES and FTH sites declined through the growing season but remained high at the MTN site, resulting in final survival of 35%, 25% and 80%, respectively. The effect of shelters on survival was minimal at all three sites. At the MTN site, however, sheltered trees were less water stressed despite receiving 60% less water than those without shelters. Protective shelters and irrigation scheduling can benefit tree establishment in a naturalized landscape by reducing water stress provided soil and climate conditions do not inherently limit tree growth.
Emergence and Shoot Growth of Cosmos and Marigold from Paclobutrazol-treated Seed
Authors: Pill Wallace G. , Gunter James A.
Published: August 2020

This study was conducted to determine whether treating seeds of ‘Sensation Mixed’ cosmos (Cosmos bipinnatus Cav.) and ‘Bonanza Gold’ marigold (Tagetes patula L.) with paclobutrazol (PB) could suppress seedling growth. Seeds were soaked in solutions of 0, 500 or 1000 mg PB/liter (ppm PB) for 16 hours at 25C (77F) or they were primed [−0.5 MPa (−5 bars) for 7 days at 20C (68F)] in Grade 5 exfoliated vermiculite moistened with 0, 500 or 1000 ppm PB solltuions. Soaked and primed seeds were dried for 1 day at 19C (65F) and 25% relative humidity. These seeds and control (non-treated) seeds were sown into plug cells containing peat-lite. Increasing PB concentration decreased cosmos shoot height at 32 days after planting (DAP), but decreased emergence percentage, responses that were more pronounced with priming than with soaking. A 1 ppm PB growth medium drench [30 ml/cell(0.2 mg PB/cell)] and, to a greater extent a 10 mg PB/liter (ppm PB) shoot spray [2 ml/shoot (0.02 mg PB/shoot)], both applied at 10 DAP, resulted in greater cosmos shoot height suppression at 32 DAP than treatment of seeds with 1000 ppm PB. Soaking marigold seeds in 1000 ppm PB failed to decrease shoot height below those of plants from non-treated seeds at 32 DAP. However, exposure to 1000 ppm PB during priming of marigold seeds resulted in a similar shoot height suppression (13%) as the growth medium drench, and similar shoot dry weight reduction (21%) as the shoot spray. Suppression of shoot growth by this seed treatment was short-term since by five weeks after transplanting into 15 cm (6 in) pots, only marigold plants that had received the growth medium drench or shoot spray were smaller than those of control plants. Treating marigold seeds with 1000 mg ppm PB used about one-fifth the PB used to drench the growth medium.
Evaluation of Dogwood and Birch Species and Cultivars for Resistance to Key Insect Pests and Diseases
Authors: Johnson Monte P. , Hartman John R. , McNiel Robert E. , Fountain William M.
Published: August 2020

Ten cultivars of dogwoods (Cornus spp.) were evaluated in multi-year trials for relative reisistance to the dogwood borer, Synanthedon scitula (Harris); cold injury; canker disease, Botryosphaeria dothidea; spot anthracnose, Elsinoe corni; and powdery mildew, Oidium sp., Microsphaera sp., and Phyllactinia sp. Similarly, eight cultivars of birch (Betula spp.) were evaluated for resistance to the birch leafminer, Fenusa pusilla (Lepeletier); Japanese beetle, Popillia japonica Newman; aphids, Hamamelistes spinosus Shimer; the bronze birch borer, Agrilus anxius Gory; and leaf-spot, Cryptocline betularum. All cultivars of C. florida, C. kousa and C. kousa x florida were susceptible to dogwood borer, although the C. florida cultivars were surviving better than the others. Cornus mas and C. kousa cultivars were relatively resistant to powdery mildew while C. florida x kousa hybrids and C. florida ‘Cherokee Brave’ were intermediately resistant. Betula platyphylla szechuanica ‘Purpurea’ was highly susceptible to the bronze birch borer, whereas B. nigra and B. n. ‘Heritage’ were the most susceptible birches to aphid damage. Betula jacquemontii was highly susceptible to Japanese beetle defoliation. Betula pendula, B. nigra, and B. n. ‘Heritage’ were most susceptible to defoliation by birch leaf spot. This study suggests that dogwood and birch cultivars vary in susceptibility to key insect pests and diseases. Planting relatively resistant cultivars may be useful in managing perennial pests in urban landscapes.
Evaluation of Eleven Newly Acquired Asian Elms for Their Suitability to Adult Elm Leaf Beetle (Coleoptera: Chrysomelidae)
Authors: Miller Fredric , Ware George
Published: August 2020

Eleven newly introduced Asian elm species and one reference species were evaluated in no-choice laboratory bioassays for their suitability to the adult elm leaf beetle, Xanthogaleruca (= Pyrrhalta) luteola Müller. Adult female beetles laid significantly more eggs on U. bergmanniana, U. bergmanniana var. lasiophylla, U. castaneifolia, U. gaussenii, U. lamellosa, and U. pumila, indicating these species were the most suitable for ELB. The least suitable species for adult beetle feeding and reproduction were U. chenmoui, U. elongata, U. glaucescens, U. propinqua, U. propinqua var. suberosa, and U. szechuanica. Adult female beetles laid eggs within 7–10 days, or 4 days earlier, on the most suitable elms compared with beetles feeding on the least suitable elms. Adult male and female longevity was significantly affected by host suitability with adult males and females living nearly twice as long on the most suitable elms compared to the less suitable elms. Least suitable species U. chenmoui, U. elongata, U. glaucescens, U. propinqua, and U. szechuanica offer resistance to elm leaf beetle and show promise for future elm breeding programs.
Fertilization of Container-Grown Baldcypress (Taxodium distichum (L.) Rich.)
Authors: Hinesley L. Eric , Smith Scott A. , Wicker A. M.
Published: August 2020

Two fertilization experiments were conducted with first-year seedlings of baldcypress [Taxodium distichum (L.) Rich.] in containers (substrate = composted pine bark). First, seedlings were subjected to factorial combinations of dolomitic lime, soluble fertilizer (SF), and incorporated controlled-release fertilizer (CRF) (19.0N–2.6P–8.8K; 8- to 9-month release). Lime decreased growth. Incorporated CRF [4.8 kg/m3 (8 lbs/yd3)] yielded more growth than a single weekly application of SF (N = 0.5 g/liter). In the second experiment, most of the potential height growth and total plant dry weight were realized with 2.4 kg/m3 (4 lbs/yd3) and 4.8 kg/m3 (8 lbs/yd3), respectively, of incorporated CRF. At optimal growth, foliar N concentrations were 3.0%.
Yard Waste Compost as a Landscape Soil Amendment for Azaleas
Authors: Beeson R.C. , Keller Karen G.
Published: August 2020

Azaleas, Rhododendron indicum L. ‘G.G. Gerbing’, were transplanted into landscape beds amended with yard waste compost at rates of 0, 5.1, 7.6, or 10.2 cm (0, 2, 3, or 4 in) incorporated into the top 18 cm (7 in) of a sandy soil. Plants were irrigated on alternate days (high irrigation rate) or on every third day (low irrigation rate), and shoot and root growth measurements were recorded at 0, 4, 8, 12, and 18 months after transplanting. Differences among compost treatments for plant quality and root elongation were observed after 8 months. By 18 months, incorporation of 7.6 or 10.2 cm (3 or 4 in) of compost resulted in plants with larger shoots, greater root, elongation, and larger root masses compared to the 0 and 5.1 cm (2 in) compost treatments. The larger azalea shoots and roots achieved with high rates of compost occurred under both irrigation regimes. Incorporating 7.6 or 10.2 cm (3 or 4 in) of compost increased root elongation, mostly between 4 and 8 months, and increased root mass after 12 months. Compost incorporation affected the quality of plants under high irrigation, with 10.2 cm (4 in) of compost producing the highest-quality plants.
Modification of Ponderosa Pine Root Systems in Containers
Authors: McDonald S.E. , Tinus R.W. , Reid C.P.P.
Published: August 2020

Coating the inside surfaces of containers with cupric carbonate (CuCO3) caused roots of ponderosa pine (Pinus ponderosa Laws.) to stop growth when they contacted the container wall. Higher order laterals then proliferated and were arrested when they, in turn, encountered the container wall. These roots resumed growth radially when the container was removed. Indolebutryic acid (IBA) caused a similar, but not as dramatic effect as CuCO3.
Influence of Ozone on the Severity of Phytophthora Root Rot of Azalea and Rhododendron Cultivars
Authors: Moore Laurence D. , Lambe Robert C. , Wills Wirt H.
Published: August 2020

The susceptibility of 21 azalea and rhododendron cultivars to colonization by Phytophthora cinnamomi and to injury caused by ozone was determined. Resistance to P. cinnamomi was lacking in most cultivars with only 3 rhododendron cultivars ‘Caroline,’ ‘Chionoides’ and ‘English Roseum’ and 3 azalea cultivars ‘Hinodegiri,’ ‘Sweetheard Supreme’ and ‘Tradition’ having resistance. All of the rhododendron cultivars, except ‘Nova Zembla,’ were highly resistant to ozone injury. Of the azalea cultivars, only ‘Delaware Valley White,’ ‘Roadrunner’ and ‘White Water’ exhibited injury following fumigation with 0.20 ppm ozone for 6 hours on 3 consecutive days. The fumigation of P. cinnamomi-inoculated plants with ozone significantly increased the severity of Phytophthora root rot only in ‘Hinodegiri’ plants, but a trend towards greater disease severity was evident in many cultivars.
Chemical Control of the Cypress Twig Gall Midge, Taxodiomyia cupressiananassa in Central Illinois
Authors: Chen C. , Appleby James E.
Published: August 2020

One to 4 foliar sprays of diazinon, dimethoate (Cygon), and malathion were made at 10 day intervals beginning May 16 to control the cypress twig gall midge on bald cypress trees in central Illinois. Three applications of dimethoate gave best control. All sprays were phytotoxic, with dimethoate causing the least noticeable injury.
Propagation of Southern Waxmyrtle by Stem Cuttings
Authors: Blazich Frank A. , Bonaminio Vincent P.
Published: August 2020

Southern waxmyrtle (Myrica cerifera L.) stem cuttings rooted in high percentages when taken in a transitional growth stage between a softwood and semi-hardwood condition and maintained under intermittent mist. Indolebutyric acid (IBA) treatments (1000 to 4000 ppm) had little effect on increasing percent rooting but greatly stimulated root number and length.
Making Plants a Way of Life2
Authors: Lumis Glen P.
Published: August 2020

Why do western Europeans have a greater appreciation of landscape plants and gardening than North Americans? This topic is explored by focusing on history and tradition, life styles, land area and climate. Can North Americans emulate the European awareness? The nursery industry is a part of our cultural maturity and should concentrate on leisure time activity, education, advertising and product improvement.
Rooting of Three Landscape Species in Gasifier Residue-Based Propagation Media
Authors: Regulski F.J.
Published: August 2020

The rooting of azalea (Rhododendron indicum L. ‘Prudence’), privet (Ligustrum sinensis L.), and boxwood (Buxus microphylla japonica L. ‘Richardii’) hardwood cuttings in 5 propagation media composed of combinations of gasifier residue (GR), Canadian sphagnum peat (P), and/or horticultural perlite (Per) indicated that superior root initiation and root development occurred in several GR:P media mixtures. Rooting of both azalea and privet was greater in the 3GR:1P medium than in 1P:1Per. Boxwood root development was superior in both the 1GR:1P and 3GR:1P media than the 1P:1Per medium. The percent air space of gasifier residue-based media did not change over 16 weeks of greenhouse exposure, however there was nearly a 50% reduction of air space in 1P:1Per medium.
Effect of Age and Handling on Subsequent Growth and Development of Areca Palm, Chrysalidocarpus lutescens, Seedlings
Authors: Murakami Paul K. , Rauch Fred D.
Published: August 2020

This study was initiated to determine the optimal stage to transplant Areca Palm, Chrysalidocarpus lutescens H. Wendl., seedlings and to determine their tolerance to adverse handling during transplanting. Best growth and less plant loss occurred when transplanting was done at an early developmental stage (spike or 1st-leaf stage compared to 2nd-leaf stage). Growth reduction and losses were minimized when minimum root disturbance and desiccation occurred.
Douglas Fir Seed Sources Tested for Christmas Trees in Connecticut
Authors: Jaynes R.A. , Stephens G.R. , Ahrens J.F.
Published: August 2020

Douglas fir, Pseudotsuga Menziesii (Mirb.) Franco, is a popular Christmas tree in the Northeast. In 1976 trees from 11 geographic sources ranging from British Columbia to southern Arizona and New Mexico were planted in a replicated design and managed as a commercial plantation. Information was also obtained on 10 seed sources grown on a commercial tree farm. All sources were hardy in the Connecticut plantings. In general, trees from southern Rocky Mountain sources were bluer, and grew faster than those from northern sources, but they were also more susceptible to attack by Cooley gall aphid, Adelges cooleyi (Gill), and rhabdocline needle cast fungus, Rhabdocline pseudotsugae (Syd.)
Efficacy and Phytotoxicity of Selected Pesticides for the Suppression of the Brown Garden Snail, Helix aspersa
Authors: Parrella Michael P. , Schultz Peter B.
Published: August 2020

Molluscicides for control of the brown garden snail (Helix aspersa) were evaluated and liquid formulations of Guthion (azinphosmethyl) and Zectran (mexacarbate) provided the most rapid and greatest kill. With granular formulations, snail mortality was highest (92%) using a 4% metaldehyde formulation at 67 kg ai/ha (60 lbs ai/acre). Applications of Guthion (azinphosmethyl), Zectran (mexacarbate) and Mesurol (methiocarb) at 4 g ai/l (equivalent to 4 lbs/100 gal) to 20 species of woody and herbaceous plant species resulted in no observed phytotoxicity.
Early Selection for Wound Compartmentalization Potential in Woody Plants
Authors: Santamour Frank S.
Published: August 2020

Young woody plants may be successfully screened for their genetically controlled potential to compartmentalize discolored and decayed wood associated with trunk wounds to small columns. To test woody plants for their compartmentalization potential, there should be a reasonable amount of xylem tissue, about 2 years' growth, interior to the experimentally inflicted wound and at least one full growing season should occur between the time of wounding and examination.
The Impact of Root Lesion Nematodes on Woody Plants
Authors: Walker J.T.
Published: August 2020

Lesion or meadow nematodes are not as well known to the plantsmen as common root-knot species, yet they do cause injury to fruit trees, woody landscape plants, and to some extent, forest (nursery) trees. Studies by numerous researchers have demonstrated that Pratylenchus species cause wilting, off-color foliage, fruit reduction, less root growth and general growth suppression. Research highlights of the past several decades are discussed in terms of the general effects these soil-inhabiting species have on plants and points are raised concerning the future research needed to better assess the impact of lesion nematodes on plants.
Root Pruning but not Irrigation in the Nursery Affects Live Oak Root Balls and Digging Survival
Authors: Gilman Edward F. , Stodola Ann , Marshall Michael D.
Published: August 2020

Irrigation placement and irrigation volume during field production of live oak (Quercus virginiana Mill.) in a sandy soil had no effect on trunk caliper [mean = 6.3 cm (2.5 in)] or tree height [mean = 3.8 m (12.4 ft)]. Root pruning had no impact on caliper and a slight (P < 0.06) impact on height. Irrigation placement and volume had little effect on number of cut roots at the edge of the root ball. Root pruning with a hand spade or in combination with root-pruning fabric placed under the liner at planting increased the number of roots at the edge of the root ball. Root pruning with fabric in combination with spade pruning increased the small-diameter (<5 mm) root weight: shoot ratio but reduced the total root weight: shoot ratio. Irrigation placement and volume during production did not affect summer nor winter digging survival. Trees that were not root pruned had poorer survival in the summer and winter digging seasons than those receiving either of the root-pruned treatments. In contrast, summer and winter survival was similar for root-pruned trees indicating that live oak can be dug in summer as well as the more traditional winter period as long as trees are root pruned during production. Trees pruned with fabric placed under the liner at planting in combination with spade pruning survived better than traditional spade root pruned trees.
Atrimmec Suppresses Shoot Length and Promotes Branching of Lonicera x heckrottii ‘Goldflame’ (Goldflame Honeysuckle)
Authors: Bruner L.L. , Keever G.J. , Kessler J.R. , Gilliam C.H.
Published: August 2020

Studies were conducted in 1999 and 2000 to determine effects of Atrimmec (dikegulac-sodium) applied at 0, 2340 or 4680 ppm and pruning just prior to Atrimmec application (1999 only) on shoot length and shoot number of Lonicera × heckrottii ‘Goldflame’ (Goldflame honeysuckle). When Atrimmec was applied in June 1999, shoot lengths were suppressed in non-pruned plants 21–24% 2 weeks after treatment (WAT), 16–19% 4 WAT, 16–17% 8 WAT, and 15–16% 10 WAT compared to control plants. Shoot length was suppressed 933% in pruned plants from 2 through 10 WAT, with increased suppression from concurrent pruning evident in control plants 2 WAT, and for plants treated with the higher Atrimmec rate 2 through 10 WAT. Following 10 WAT, increasing Atrimmec rate suppressed shoot length linearly and independent of pruning, 15–21% 12 WAT and 14–21% 14 WAT. When Atrimmec was applied in April 2000, shoot length of non-pruned plants was suppressed quadratically by increasing Atrimmec rate with suppression at the highest rate (4680 ppm) of 17% 2 WAT, 24% 4 WAT, 21% 6 WAT, 22% 8 WAT, and 20% 10 WAT. In 1999, Atrimmec and pruning affected shoot number independently. There was a linear and later a quadratic increase in shoot number with increasing Atrimmec rate of 44–122% 6 WAT, 18–68% 8 WAT, and up to 24% 10 WAT. Shoot number of non-pruned plants was greater than pruned with mean increases of 8 shoots 6 and 8 WAT and 5 shoots 10 WAT. Increasing rates of Atrimmec increased shoot number in the 2000 study up to 62% 2 WAT, 47–106% 4 WAT, 57–67% 6 WAT, and 9-27% 8 WAT.
Soybean Oil Controls Two-Spotted Spider Mites on Burning Bush
Authors: Lancaster Aaron L. , Deyton Dennis E. , Sams Carl E. , Cummins John C. , Pless Charles D. , Fare Donna C.
Published: August 2020

Summer sprays of soybean (Glycine max (L.) Merrill) oil were evaluated for efficacy against two spotted spider mites (Tetranychus urticae Koch) (TSSM) on burning bush (Euonymus alatus Thunb.). Single sprays of 1, 2, or 3% soybean oil or 1% SunSpray reduced TSSM populations by 97–99% compared to water-sprayed controls. Single sprays of 2 or 3% soybean oil were not phytotoxic but suppressed photosynthesis for a short time. In a second experiment, a single spray of 0.75, 1.0, or 1.5% soybean oil reduced the TSSM population by > 95%, compared to the water control. A second spraying of 0.25–1.5% soybean oil resulted in ≥ 93% control of TSSM compared to the water control. A third spray provided little additional TSSM control. Predaceous mites were not initially disrupted by a single spray of soybean oil or SunSpray Ultra-fine spray oil. A single spray of ≤ 1.5% soybean did not significantly reduce photosynthesis. Soybean oil had efficacy against TSSM similar to that of SunSpray and had similar effects on photosynthesis. Soybean oil was less phytotoxic and caused less defoliation of stressed plants than did SunSpray in one experiment but not in two other experiments. Results show that soybean oil could be used in an integrated pest management program for managing spider mites on ornamentals.