bluuebunny/crossref_metadata_2025 huggingface dataset:
Metolachlor and Simazine Leaching through Horticultural Substrates
Authors: Mahnken G.E. , Skroch W.A. , Sheets T.J. , Leidy R.B.
Published: August 2020

This study was designed to determine whether differences existed in the amount of Derby (metolachlor and simazine) leached through four substrates used in container production. Substrate compositions (by vol) used in this study were 3:1 redwood bark:sand, 2:1:1 redwood bark:Yolo loam:sand, 3:1 pine bark:sand, and 1:1 composted hardwood bark:pine bark. Substrates were packed into #3 containers, and 4.5 kg ai/ha (4 lb ai/A) of metolachlor and 1.1 kg ai/ha (1 lb ai/A) of simazine were applied to the containers as a granular formulation. Containers were leached with 2.7 cm (1.06 in) of water per day, and leachate samples were collected 0, 1, 2, 4, 8, and 16 days after herbicide application. Both herbicides were detected in the redwood bark:sand leachate on the day of herbicide application, and concentrations increased over time but appeared to level off between day 8 and day 16. Metolachlor and simazine were detected in the redwood bark:Yolo loam:sand leachate 4 days after application, and concentrations of both herbicides increased over time. Metolachlor and simazine were detected in a few leachate samples from the hardwood bark:pine bark and pine bark:sand substrates. Substrate ranking based on the amount of herbicide lost was 3:1 redwood bark:sand >2:1:1 redwood bark:Yolo loam:sand >1:1 hardwood bark:pine bark >3:1 pine bark:sand.
Influence of Irrigation Water Salinity on Optimal Nitrogen, Phosphorus, and Potassium Liquid Fertilizer Rates for Spathiphyllum ‘Petite’
Authors: Campos Ricardo , Reed David Wm.
Published: August 2020

The experiment was a 5 × 5 factorial composed of 5 fertilizer levels and 5 salinity levels applied to Spathiphyllum ‘Petite’. Fertilizer levels were 0, 125, 250, 375 and 500 mg/l (ppm) N from a 24N-3.4P-13.3K (24-8-16) soluble fertilizer. Salinity levels were 0, 500, 1000, 1500 and 2000 mg/l (ppm) from NaCl:CaCl2 in a 1:1 equivalent ratio. Maximum growth was observed at 250 mg/l N and no salts. At the highest salinity level tested (2000 mg/l), maximum growth was observed at 125 mg/l N. Generally, as salinity level increased the measured growth parameters decreased. Leaf calcium, sodium, and chloride increased with increasing levels of salinity in the irrigation water. Leaf nitrogen, phosphorus, and potassium generally increased with increasing levels of fertilizer, but were not affected by salinity levels. It is possible that high sodium and chloride concentration in leaves produced an ion toxicity.
The Contribution of Landscaping to the Price of Single Family Houses: A Study of Home Sales in Greenville, South Carolina
Authors: Henry Mark S.
Published: August 2020

The market for housing is often analyzed from the hedonic perspective where the characteristics of the house and its location together influence its market price. In this study, the contribution of the quality of landscaping to the house price is estimated. Using data from a sample of 288 recent home sales in Greenville, South Carolina, a linear in the logs regression of house price on house characteristics, location and landscape quality was estimated. A house that obtained an excellent landscaping rating from a local landscaping professional could expect a sales price of about 4 to 5 percentage points higher (depending on the size of the lot) than equivalent houses with good landscaping. Homes with landscaping appeal far below (fair or poor) neighboring homes with excellent landscapes can expect a sales price 8–10% below equivalent homes with good landscaping appeal.
Persistent Effects of Plant Growth Regulators on Landscape Performance of Seed Geraniums
Authors: Latimer Joyce G. , Baden Sherrod A.
Published: August 2020

In 1988, spray applications of 3.5 or 7 ppm paclobutrazol, 1500 ppm chlormequat, or 200 ppm ancymidol were applied to seed geraniums (Pelargonium x hortorum L. H. Bailey ‘Ringo White’ and ‘Ringo Rose’) to determine effects on growth in the greenhouse and the subsequent growth and performance of treated plants in the landscape. All growth retardants reduced stem length and shoot dry weight as well as time required for flowering, while branching was increased relative to the untreated plants. Flowering in the landscape was increased by all growth regulator treatments at 4 weeks after planting but was generally not different from the untreated plants at 6 weeks after planting. Plant height and width were reduced by all treatments for both cultivars, relative to untreated plants, at 4 weeks after planting. However, only 7 ppm paclobutrazol reduced height and width of ‘Ringo White’ plants at 6 weeks after planting. Plant height, but not width, was reduced by all treatments for ‘Ringo Rose’ at 6 weeks after planting.

In 1989, seedlings of ‘Ringo Rose’ were treated with 3.5, 7, 16, 40, or 80 ppm paclobutrazol or 1500 ppm chlormequat or 200 ppm ancymidol. Seedling growth was excessively reduced by 40 or 80 ppm paclobutrazol. Time required for flowering was not reduced by growth regulators in 1989. Landscape performance under conditions of excess rain was not improved by plant growth regulators and the height of plants treated with 16, 40 or 80 ppm paclobutrazol was still less than that of the untreated plants at 12 weeks after planting. Only chlormequat controlled plant growth in the greenhouse without delaying the resumption of growth in the landscape.
Cyclic Sprinkler Irrigation of Container Substrate Affects Water Distribution and Marigold Growth
Authors: Karam Nabila S. , Niemiera Alexander X. , Leda Carol E.
Published: August 2020

Two experiments were conducted to determine how cyclic sprinkler irrigation (daily water allotment applied in more than one application) influenced water distribution and leaching, and marigold growth in a pine bark (PB) or a PB:sand (S) substrate. Marigolds (Tagetes erecta L. ‘Apollo’), were grown in PB-filled 3.8 liter (1 gal) containers. Substrate was allowed to dry via evapotranspiration (ET) to targeted pre-irrigation substrate water contents (PSWC) and respective ET volumes were applied as a single application (continuous) or by multiple applications (cyclic irrigation) via a simulated sprinkler irrigation system; leachates were collected. In the first experiment, the influences of irrigation method, continuous and cyclic irrigation, on water distribution in the top, middle and bottom substrate (9: 1pine bark to sand, by vol) sections were investigated. Two hundred seventy five (275) ml were applied continuously or cyclically (three 92 ml allotments with 1 hr interval between applications) to containers at 84 % of container capacity (CC). In the second experiment, marigolds were grown in a growth chamber for three weeks and received 12 irrigations. In each irrigation, a complete nutrient solution was applied continuously or cyclically (three applications each of one-third of the total volume with 1 hr between applications). Substrate solution N concentration (via pour-through method), leachate N, and plant growth was measured. In the first experiment, gravimetric water contents of top and middle substrate sections were similar, whereas the water content of the bottom section was higher with cyclic than with continuous. In the second experiment, root dry weight was 43% higher, shoot fresh and dry weights were similar, and plant N concentration was 0.7% higher (absolute basis) with cyclic than with continuous irrigation. Irrigation method had no influence on substrate solution and leachate NO3-N and NH4-N concentrations. However, total N leached was 43% higher with continuous than with cyclic irrigation. These results demonstrate that cyclic irrigation increased root N concentration and root growth without a toxic accumulation of N in the substrate solution.
Micropropagation of Gas Plant (Dictamnus albus L.)
Authors: Jones Rodney O. , Geneve Robert L. , Kester Sharon T.
Published: August 2020

Gas plant.(Dictamnus albus L.) was successfully micropropagated from greenhouse-grown plants capable of flowering. Stems from initial spring growth were surface disinfested and two- node sections were placed horizontally on modified Murishige and Skoog medium with 1 μM (0.2, ppm) benzyladenine (BA). A dose response to BA at 1,5 and 10 μM (0.2, 1.1,2.3 ppm) indicated that the greatest number of usable microshoots was observed in cultures from horizontally placed explants treated with 1 μM (0.2 ppm) BA. These cultures initiated between 7.6 and 9.5 shoots per culture with approximately 70% of the shoots greater than 2 cm (0.8 in). Microcuttings rooted poorly in vitro even with indolebutyric acid in the medium. However, microcuttings rooted between 71 and 86 percent under ex vitro conditions. Microcuttings either untreated or treated with indolebutyric acid (5,000 or 10,000 ppm) as a quick dip produced 1.8 to 2.6 roots per rooted cutting after being directly stuck in a peat-lite medium (Metro-Mix or Promix) in cell packs under high humidity. Untreated microcuttings rooted at higher percentages (67 to 88%) in peat-lite media compared to perlite or vermitculite (25 to 58%). Rooted microcuttings were successfully acclimatized to greenhouse conditions by gradually reducing humidity.
Water Relations and Growth of Vinca Following Chemical Growth Regulation
Authors: Fuller Kim P. , Zajicek Jayne M.
Published: August 2020

Growth of vinca (Vinca major (L.)) was limited by either a medium drench application of uniconazole of 2 or 4 mg a.i. per pot or a foliar spray application of 2, 4, or 6.25 mg a.i. per plant, both applied in 25 ml (0.75 fl oz) of water. Shoot length, leaf number, leaf area, leaf dry weight and stem dry weight averaged over uniconazole treatments were 51%, 45%, 32%, 33%, and 38% less than control plants, respectively. When compared to control plants, water use of chemically treated plants was reduced by 35% due to the reduction of leaf area and also lower stomatal conductance readings. Stomatal conductance readings of chemically treated plants were 2 to 5 times less than control plants indicating the plant size was not the only factor affecting plant water use.
Landscape Installation Firms: II. Source of Plant Material
Authors: Garber M.P. , Bondari K.
Published: August 2020

The plant material purchasing patterns of landscape installers, which could help nurserymen develop marketing plans for this important segment of the green industry are identified in this study. Landscape installers revealed that approximately 97% of Georgia landscape installation firms purchased plants in-state and, in-state purchases were 73% of all plant material purchases. Most firms (91%) purchased directly from growers and obtained the largest percentage of plant material from this source (59.4%). The most important factors in selection of the production nursery where plants were purchased, as judged by the percent response for ‘very important’, were plant quality (85.3%), availability of plant material in desired sizes (62.7%) and, availability of plant varieties (60.0%). The quality of eight categories of plants grown in Georgia, relative to other states, was favorable. Landscape installation firms expected to purchase the same or greater quantities of plants over the next five years. The top three plant material trends likely to affect the type of plants purchased by landscape installers were decreased water availability (23.7%), increased demand for low maintenance landscapes (21.4%) and increased use of native or stress tolerant plants (17.6%). Across all size firms, the two most frequently listed opportunities for plant producers to help landscape installers were improved size and quality standards, and awareness of plant material specified by landscape architects so requested material is available. The results in this study varied by size of firm and provide valuable insight for development of marketing plans for growers serving the landscape installation industry.
Propagation of Pistacia chinensis by Mound Layering
Authors: Dunn Diane E. , Cole Janet C.
Published: August 2020

Chinese pistache (Pistacia chinensis, Bunge.) is a commonly recommended landscape shade tree in the nursery and landscape industry. Currently, Chinese pistache trees are propagated commercially from seed, which results in highly variable branch habit and fall color. Mature Chinese pistache, like other Pistacia have proven difficult to root, graft, or bud successfully. This study was initiated to investigate the potential of mound layering as an alternative vegetative propagation method for producing genetically identical clones of superior mature Chinese pistache trees. Results from a greenhouse pre-trial in which trees were cut at two different heights and at three different morphological stages showed that significantly more shoots were produced when stock plants were cut 5 cm (2 in) above the soil line compared to 1 cm (0.4 in), and when trees completely broke dormancy before cutting. Field trials during two consecutive years evaluated four treatments consisting of 1) wound; 2) 17,500 ppm IBA; 3) wound and 17,500 ppm IBA 4) no wound, no IBA. In 1993, 77% and in 1994, 75%of wounded shoots treated with IBA produced roots.
Growth Control of Asiatic Jasmine and Carolina Jessamine with Uniconazole
Authors: Keever Gary J. , Foster William J.
Published: August 2020

A single foliar spray of 75 to 300 ppm uniconazole suppressed runner elongation of Trachelospermum asiaticum (Siebold & Zucc.) Nakai (Asiatic or Japanese star jasmine) for 9 weeks. Uniconazole did not, however, affect number of runners exceeding 20.3 cm (8 in) in length or shoot dry weight. Two foliar sprays of 300 to 900 ppm uniconazole or two drench applications of 3 to 20 mg ai/pot, applied 6½ weeks apart, suppressed lengths of the longest runners for at least 19 and 6 weeks, respectively, and runner number exceeding 20.3 cm (8 in) and shoot dry weight for 46 weeks. Two foliar sprays of 75 to 300 ppm uniconazole or two drench applications of 1 to 5 mg ai/pot, applied 14 weeks apart, reduced shoot dry weight of Gelsemium sempervirens (L.) Ait. (Carolina jessamine) 38 and 59 weeks after initial treatment, but had no effect on shoot length as early as 14 weeks after initial treatment. Shoot length of jessamine was reduced 6 and 19 weeks after initial treatment with two foliar sprays of 300 to 900 ppm uniconazole or two drench applications of 3 to 20 mg ai/pot. Foliar rates of 600 or 900 ppm and drench rates of 10 to 20 mg ai/pot suppressed shoot growth of jessamine excessively and were considered unacceptable.
Turf Herbicide Injury to Landscape Trees as Influenced by Mulch
Authors: Smith L.J. , Skroch W.A.
Published: August 2020

A two year field study was conducted in 1991 and 1992 to evaluate the sensitivity of landscape trees to certain turf herbicides as affected by mulch. The study included four tree species (‘Bradford’ callery pear, crape myrtle, Eastern redbud, red maple), four mulch treatments (shredded hardwood bark, pine bark, pine needles, no mulch), and six herbicide treatments [Banvel (dicamba), BAS 514 OOH (quinclorac), Image (imazaquin), Redeem (triclopyr), Stinger (clopyralid)]. Herbicides were applied as directed sprays at the labeled rates for use on turf. Visual injury (%) ratings were measured at 30, 60, 90, 120, and 150 days after treatment. Trunk diameters and total plant fresh weights were measured at the conclusion of the study. In most cases, applying the herbicide over mulch decreased tree injury compared to applications to bare soil (Fig. 3). Red maples were most severely injured by Stinger (clopyralid) (27%) (60 DAT) and BAS 514 OOH (quinclorac) (33%) (60 DAT). Redbuds were most severely injured by the same two herbicides, but at 89% (120 DAT) and 73% (120 DAT), respectively. ‘Bradford’ pears were injured by Banvel (dicamba) (32%) (120 DAT), and crape myrtles by Image (imazaquin) (10%) (120 DAT).
Influence of Culture Age, Cytokinin Level, and Retipping on Growth and Incidence of Brooming in Micropropagated Rhododendrons
Authors: Keith Virginia M. , Brand Mark H.
Published: August 2020

Active shoot cultures of Rhododendron ‘Aglo’, ‘Molly Fordham’, and ‘Scintillation’ were maintained on four levels [10, 20, 30, and 40 μ M (2, 4, 6 and 8 ppm)] of N6-(2-isopentenyl)adenine (2iP) for five months. Growth characteristics were evaluated at three and nine months post-acclimatization (PA). Differences in height or width were no more than 4 cm (1.6 in), and differences in branching were five branches or less. R. ‘Molly Fordham’ plants exhibiting a dwarf, brooming nature were generated from all 2iP levels, and accounted for 3–5% of all plants grown. R. ‘Molly Fordham’ plants generated from 26-week-old cultures were initially 13% taller at three months PA, and then 6% wider at nine months PA when compared to plants generated from 240-week-old cultures. Leaf area for plants generated from 26-week-old cultures was 12 or 23% greater than for plants from 240-week-old cultures. Variant plants were generated from the 26- and the 240-week-old cultures at 9% and 5% respectively, although the difference was non-significant. Rooted microcuttings (bases) of R. ‘Aglo’, ‘Molly Fordham’, and ‘Scintillation’ were cut half-way up the stem, and the top half (retips) were rooted also. The retipping procedure produced bases that had an increased branching development (12 or 69%). The population of R. ‘Molly Fordham’ bases produced variants (9%), although the population of retips did not (0%).
Irrigation and Fertilizer Placement Affect Root and Canopy Growth of Trees Produced in In-ground Fabric Containers
Authors: Beeson R.C. , Gilman E.F.
Published: August 2020

Live oak (Quercus virginiana Mill.) and Chinese elm (Ulmus parvifolia Jacq. ‘Drake’) were transplanted from 3.8 liter (#1) containers into 35-cm (14 in) fabric containers in sandy soils. Irrigation or fertilizer was applied all inside, half-in half-out (50/50), or all outside the fabric container during a 2-year production cycle. For live oak, neither irrigation nor fertilizer placement increased fine root mass within the fabric container. Maximum trunk diameter was achieved by applying both irrigation and fertilizer inside the container. For Chinese elm, applying either fertilizer or irrigation inside or half-in half-outside the container increased fine root mass within the harvested root ball. Elm shoot growth was greatest with 50/50 placement of both irrigation and fertilizer. Field site influenced the effect of Irrigation on shoot growth, but not root mass. Greater fine root mass occurred in the heavier soil type
Effects of Shade Level and Fertilizer Rate on Yield and Vase Life of Aspidistra elatior ‘Variegata’ Leaves
Authors: Stamps Robert H.
Published: August 2020

Aspidistra elatior ‘Variegata’ plants were grown for 3.75 years in containers under 63% or 73% shade and fertilized with controlled release fertilizer at rates equivalent to 448, 896, 1344 or 1792 kg N/ha (400, 800, 1200 or 1600 lb N/A) per year. Yield of variegated, but not all-green, leaves was greater under 63% than under 73% shade. Combined yield of green and variegated leaves produced under 63% shade was 42% greater by weight and 47% greater by number than under 73% shade. Fertilizer rate did not affect total yield and neither fertilizer rate nor shade level affected the percent of total leaf production that was green. Leaves were harvested August 1990, January 1991, November 1991 and March 1993 for vase life determinations. Harvested leaves were stored for one week at 4C (40F) and evaluated under indoor conditions of 23 ± 2C. (74 ± 4F), 60 ± 16% relative humidity and 12-hour photoperiod at 17 μmol·m−2·S−2 (107 ft-candles). Treatments did not affect vase life except at a winter harvest when 63% shade-produced leaves lasted 14% longer than 73% shade-produced leaves. Average overall vase life for each of four harvests ranged from 22 to 34 days.
Development of Embryo Rescue and Shoot Regeneration Techniques in Ilex
Authors: Mattis Pamela R. , Swartz Harry Jan , Eisenbeiss Gene
Published: August 2020

Studies were conducted on embryo rescue and shoot regeneration from juvenile leaves to develop a system to improve Ilex using in vitro techniques. Unlike previous reports for Ilex, embryo germination and growth in the eight species tested was not consistently affected by light. Gibberellic acid had little effect on excised embryo germination in August through October; however, embryo germination was completely inhibited by 3 μM GA in November and December.

Shoot regeneration was obtained from juvenile leaves of Ilex myrtifolia and I. opaca, the two species tested. Thidiazuron, at concentrations from 5 to 50 μM, consistently resulted in the largest percentage shoot regeneration, when compared to benzyl adenine or a lower rate of thidiazuron. Indole butyric acid or pretreatment of source shoots with cytokinin or auxin did not increase regeneration percentages. Colchicine treatment of source shoots had an effect on regeneration; 100 μM was slightly stimulatory while 5 μM was significantly inhibitory. This protocol has resulted in regeneration rates that appear suitable for production of polyploid or transformed plants.
Water Conservation Potential and Quality of Non-turf Groundcovers versus Kentucky Bluegrass under Increasing Levels of Drought Stress
Authors: Staats David , Klett James E.
Published: August 2020

In June 1991, a 2-year field study was initiated to examine if three non-turf groundcovers require less irrigation than Kentucky bluegrass (KBG). Irrigation treatments were based on decreasing percentage of évapotranspiration (ET) (100%, 75%, 50%, 25% and 0%). ET was estimated by the modified Penman equation using alfalfa as a reference crop. Plants receiving the 0% irrigation treatment were not irrigated and relied on precipitation for survival. The groundcovers studied were Kentucky bluegrass ‘Challenger’ (Poa pratensis L.), creeping potentilla (Potentilla tabernaemontani Asch.), goldmoss (Sedum acre L.) and snow-in-summer (Cerastium tomentosum L.). Data were collected on visual ratings, growth, soil moisture and canopy temperature. Optimum irrigation for KBG was 50% ET. Cerastium required irrigation at 50%-75% of estimated ET during the initial season (1991) for optimum appearance and growth. During 1992, the plants were better established and 25% ET was optimum. Potentilla required irrigation at the 75% ET rate for optimum visual quality. Sedum maintained a good aesthetic appearance at irrigation rates as low as 25% ET and could be considered as a water-conserving alternative to KBG
Effect of Transplanting on Shoot Water Potential of Bareroot Washington Hawthorn and Norway Maple Trees
Authors: Bates Rick M. , Niemiera Alexander X.
Published: August 2020

Two-year-old Norway maple (Acer platanoides L.) and Washington hawthorn (Crataegus phaenopyrum Med.) trees were cold-stored for 2, 4, 6, 8, 10, and 12 weeks and stem water potentials were measured prior to and five days after transplanting. In a second experiment, a wax coating was applied to hawthorn trees at transplanting and shoot water potential was measured at two-day intervals for twelve days after transplanting; percent bud break was measured eight weeks after transplanting. In a third experiment, maple and hawthorn trees were stored for 2, 4, 6, 8, 10, and 12 weeks with the following tree covering treatments: whole plant covered, shoots exposed, roots exposed, and whole plant exposed, and root hydraulic conductivity was measured for each storage duration. For each storage duration, maple stem water potentials after transplanting were the same as or higher than the pre-transplant potential value; hawthorn water potentials after transplanting were generally lower than pre-transplant values. Six to eight days after transplanting, hawthorn water potentials of wax covered stems were higher than unwaxed stems. Bud break percentages were higher for trees with waxed stems than for trees without wax. Root hydraulic conductivity was the same for both species and decreased with increased storage duration and for treatments exposing roots.
Isoxaben and Isoxaben Combinations for Weed Control in Container-Grown Herbaceous Flowering Perennials
Authors: Porter Wayne C.
Published: August 2020

Gallery DF (isoxaben), Snapshot DF (isoxaben + oryzalin), and Snapshot TG (isoxaben + trifluralin) were applied to four species in 1991 and to nine species in 1992 of container-grown herbaceous flowering perennials to evaluate efficacy, phytotoxicity, and effect on plant growth. Surflan AS (oryzalin) and Treflan 5G (trifluralin) were used as standard herbicide checks. Gallery was applied at 0.56, 0.84, and 1.12 kg ai/ha (0.5, 0.75, and 1.0 lb ai/A). Snapshot DF and Snapshot TG were applied at 2.8, 4.2, and 5.6 kg ai/A (2.5, 3.75, and 5.0 lb ai/A). Coreopsis was not affected by any herbicide treatment either year. Painted daisy was injured by all treatments except Snapshot TG at 2.5 lb ai/A and Treflan. Gallery at 1.12 kg ai/ha (1.0 lb ai/A) and Snapshot DF at 5.6 kg ailha (5.0 lb ai/A), injured all species except coreopsis and hibiscus. Surflan injured gloriosa daisy (1991 only), chrysanthemumhollyhock, hibiscus, and painted daisy. Snapshot TG applied at 5.6 kg ai/A (5.0 lb ai/A) injured hollyhock. Height of coreopsis, shasta daisy, gloriosa daisy, and columbine was not affected or only slightly reduced by any treatment. Hollyhock, hibiscus, painted daisy, and chrysanthemum were generally shorter in containers treated with Snapshot DF at 4.2 kg/ha or higher rates.
Growth and Foliar Nutrient Concentrations of Crape Myrtle in Response to Disparate Climate and Fertilizer Placement in Large Nursery Containers
Authors: Martin Chris A. , Ruter John M.
Published: August 2020

A study was replicated in different climates [central Arizona (arid, Sonoran desert) and southwestern Georgia (humid, temperate)] to evaluate effects of controlled-release fertilizer placement in a bark-based container substrate on growth and foliar nutrient concentrations of Lagerstroemia indica L. × L. fauriei Koehne ‘Muskogee’ in large (#7) containers. Plants in Arizona were smaller with higher shoot-to-root ratios and higher levels of N, K, P, Fe, and Cu and lower levels ofCa and Zn in foliage compared with plants in Georgia. Differences in meteorological factors such as higher maximum and minimum temperatures and solar radiation, lower rainfall, and higher container root-zone temperatures, leachate electrical conductivity and nitrate concentrations were coincident with the smaller size and higher foliar nutrient concentration of Arizona plants. Fertilizer placed at the north exposure of container substrate increased plant size in Arizona. However, compared with growth of plants in Georgia, fertilizer placement at the north exposure in Arizona was not enough to entirely alleviate size inhibition caused by the arid Sonoran desert climate.
Identification and Control of Bacterial Contamination in Callus Cultures of Ulmus americana
Authors: Schreiber Lawrence R. , Domir Subhash C. , Gingas V.M.
Published: August 2020

Bacillus macerans Schardinger appeared on culture media and forceps used in serial transfers of Ulmus americana callus tissue after several contamination-free transfers and may have originated as an endophyte in the leaf tissue used as an explant. Bacteria remained viable on forceps stored for several weeks in 95% ethanol whether or not the excess was burned off in a flame from an alcohol lamp. Bacteria were eliminated from forceps treated similarily with 85% ethanol. The bacterium on artificially contaminated forceps remained viable after immersion up to 4 hr in either 95%, 85%, 80%, or 70% ethanol with or without flaming. Artificial contamination was eliminated, either by autoclaving for 20 min at 121C (185.8F) or exposure to a bunsen burner flame for 6-8 sec. Bacillus macerans remained viable in both naturally and artificially contaminated ethanol at dilutions of 95%, 85%, 80%, and 70%. Thus, forceps may be contaminated by latent bacteria in callus or contaminated ethanol. Ethanol may become contaminated by storage of nonsterile forceps and airborne spores introduced during routine, septic procedures.
Production Method Affects Tree Establishment in the Landscape
Authors: Gilman Edward F. , Beeson Richard C.
Published: August 2020

Trunk growth rates one year after transplanting 5 cm (2 in) caliper laurel oak (Quercus laurifolia Michx.) from above-ground plastic containers, from in-ground fabric containers or from the field (B&B) matched or exceeded growth rates before transplanting. Growth rates for all three treatments were similar seven months after transplanting. Shoots on field-grown trees grew more in the first year after transplanting than those from fabric or plastic containers. Roots removed at the time of digging were completely replaced on field and fabric container trees six months after transplanting. One year after transplanting, roots occupied the same soil volume as just prior to transplanting. Trees from plastic containers regenerated roots slower than B&B trees or those from fabric containers. When irrigation frequency was reduced 14 weeks after transplanting (WAT), trees from plastic containers were water stressed more (had more negative xylem potential) than B&B or fabric container trees. Growth rates of East Palatka holly (Ilex × attenuata Ashe. ‘East Palatka’) responded similarly to laurel oak; however hollies took longer to establish roots into landscape soil and took longer for the trunk growth rate to match that on trees prior to transplanting.
Composted Yard Waste as a Component of Container Substrates
Authors: Beeson R.C.
Published: August 2020

Rhododendron indicum (L.) Sweet ‘Due du Rohan’ and Pittosporum tobira variegata Ait. were produced in 10.2 liter (#3) containers in substrates consisting of 20, 40, 60, and 80% (v/v) composted yard waste mixed with pine bark and coarse sand. Plant growth, substrate physical properties, and N and P leachate were compared with a control substrate of pine bark fines:sledge peat:sand (3:1:1 by vol). Shoot growth of plants in compost substrates was similar or better than control plants and greater with daily irrigation compared to alternate day irrigation. Root growth and percent air porosity declined as compost composition and waterholding capacity increased. Total porosity was generally consistent throughout the study. Irrigation regime had no effect on root growth nor substrate physical properties. Ammonium, NO3-N, and P concentrations in leachates varied with substrate and time following topdressing with controlled release fertilizer. Both species grew best in the 40% compost, 50% pine bark, and 10% sand substrate.
Temperature Distribution in Large, Pot-in-Pot Nursery Containers
Authors: Young Roy E. , Bachman Gary R.
Published: August 2020

Container-grown landscape plants in the Mid-Atlantic and Southern states are exposed to wide, rapid fluctuations of temperatures, particularly during winter. Thermocouples were placed at three depths and four orientations in the soil mix of 2-year-old, Foster' hybrid holly (Ilex × attenuata ‘Fosteri’) to monitor temperature profiles of 57 liter (nominal 15 gal) containers. These containers were grown conventionally under three treatments: on a bare ground surface (control), inside plastic-film-covered hoop houses, and in the pot-in-pot (PIP) configuration below the ground surface. Temperatures were monitored during both the coldest and the warmest periods of the year in the Moncks Comer, SC, area. In the coldest period, soil temperatures averaged among depths and orientations were 3.6C (6.5F) warmer in the hoop houses than in the control, and 1.1C (2F) warmer in the PIP system than in the control. Although colder than the hoop houses, the average temperatures of the PIP container dropped below 0C (32F) only in the upper 7.6 cm (3 in). Below freezing averages were observed in the control containers, however, in all positions except the center. In the warmest period, the hoop houses were uncovered, becoming additional data points of the control treatments. The PIP system kept overall average soil temperatures 3.3C (6F) cooler than in control containers. Upon conclusion of the experiment, new (beyond transplanted root ball) root dry weights were significantly greater for PIP containers than for control containers.
Growth Response of Large, Established Shrubs to Cutless, Atrimmec, and Trim-cut
Authors: Banko Thomas J. , Stefani Marcia A.
Published: August 2020

Several species of large, established landscape shrubs were treated with different concentrations of Cutless (flurprimidol) or label concentrations of Atrimmec (dikegulac) or Trim-cut (mefluidide). Length of new shoots decreased with increasing rates of Cutless for ‘Convexa’ holly, ‘Hetzi’ juniper, Japanese cleyera, ‘Manhattan’ euonymus, thorny elaeagnus, and yaupon holly, but for most species the Cutless treatments were not as effective as Atrimmec. The 5000 ppm Cutless foliar spray was the most effective treatment for Manhattan euonymus but Atrimmec was more effective on thorny elaeagnus, ‘Convexa’ holly, yaupon holly, and Japanese cleyera. Trim-cut (1600 ppm) reduced growth of thorny elaeagnus and ‘Convexa’ holly, but not as much as Atrimmec (5000 ppm).
Styrene Lining and Container Size Affect Substrate Temperature
Authors: Brass Thomas J. , Keever Gary J. , Gilliam Charles H. , Eakes D. Joseph
Published: August 2020

The influence of container size and styrene lining on substrate temperature, and their relationship to ambient air temperature were evaluated. Maximum substrate temperatures adjacent to the west sidewall averaged 8C (14.4F) and 7C (12.6F) less in 2.7 liter (#1) and 10.3 liter (#3) containers with 2.6 mm (0.1 in) thick styrene, respectively, than in unlined containers during the summer. Maximum summer substrate temperatures in lined and unlined 10.3 liter (#3) containers were 4C (7.2F) and 5C (9F) lower, respectively, than in lined and unlined 2.7 liter (#1) containers. During diurnal periods of rapidly fluctuating winter temperatures, minimum substrate temperatures in 2.7 liter (#1) styrene-lined containers averaged 3C (5.4F) higher than in ones without styrene; styrene lining also reduced diurnal fluctuations in substrate temperatures in 2.7 liter (#1) and 10.3 liter (#3) containers by 11C (19.8F) and 7.5C (13.5), respectively, when compared to those in unlined containers. When ambient air temperature lacked wide fluctuations during winter diurnal cycles, extreme variations in substrate temperatures were not present. However, minimum substrate temperatures in styrene-lined 2.7 liter (#1) and 10.3 liter (#3) containers averaged over 2C (3.6F) and 3C (5.4F), respectively, higher than those in unlined containers.
Growth of Bedding Plants in Sphagnum Peat and Coir Dust-Based Substrates
Authors: Evans Michael R. , Stamps Robert H.
Published: August 2020

Water-holding capacity of substrates increased as the proportion of sphagnum peat and coir increased, and coir-based substrates had greater water-holding capacities than comparable peat-based substrates. There were no significant differences between coir and peat-based substrates with respect to bulk density, percent pore space and percent solids. Air-filled pore space and water-filled pore space decreased and increased, respectively, as the proportion of peat and coir increased. ‘Pink Elite’ geranium plants grown in coir-based substrates had greater root fresh weights than those grown in sphagnum-peat based substrates. Greatest root fresh weight occurred in an 80% coir and 20% perlite substrate. Days to flower, height, shoot fresh weight and number of axillary shoots were not significantly different between substrates. ‘Janie Bright Yellow’ marigold and ‘Blue Lace Carpet’ petunia plants had increased heights and shoot fresh weights when grown in coir-based substrates as compared with sphagnum peat-based substrates. Greatest heights and shoot fresh weights of petunia and marigold occurred in an 80% coir and 20% perlite substrate. Days to flower were reduced for marigold plants grown in coir-based substrates.
Reduced Leaching Fractions Improve Irrigation Use Efficiency and Nutrient Efficacy
Authors: Tyler Helen H. , Warren Stuart L. , Bilderback Ted E.
Published: August 2020

An experiment with two leaching fractions (LF = volume of water leached ÷ volume of water applied) and two fertilizer rates was conducted to evaluate the effects of reduced irrigation volume in combination with reduced fertility on irrigation use efficiency, nutrient efficacy (retention), and plant growth. Rooted cuttings of Cotoneaster dammeri Schneid. ‘Skogholm’ were potted into 3.8 liter (#1) containers in a pine bark: sand substrate (8:1 by vol). Osmocote 24N-1.7P-5.8K (24-4-7) was topdressed at 3.5 g N or 1.75 g N per container at treatment initiation. The experiment, a RCBD with four replications was conducted for 100 days on a container-grown plant production area subdivided into 16 separate plots that allowed for the collection of all irrigation water leaving each plot. Twenty containers were placed in each plot. Irrigation water was applied daily to attain either a high LF of 0.4 to 0.6 or a low LF of 0.0 to 0.2. Irrigation water was applied in two cycles with a two hour rest interval between each application via pressure compensated spray stakes at a rate of 200 ml/min (0.28 in/min). Volume of effluent from each plot was measured daily and analyzed for NO3, NH4, and P. Low LF decreased irrigation volume and effluent volume by 44% and 63%, respectively, compared to high LF. Irrigation use efficiency [total plant dry weight (volume applied-volume leached)] by plants irrigated with low LF was 29% greater than high LF. Compared to high LF, low LF decreased cumulative NO3 and NH4 contents in effluent by 66% and 62%, respectively, for containers fertilized with 3.5 g N. Low LF also reduced cumulative P content in the effluent by 57% compared to high LF. Shoot and total plant dry weights produced with low LF were reduced 8% and 10%, respectively, compared to plants grown with high LF. Root dry weight was not effected by LF. Shoot, root, and total plant dry weights with 1.75 g N were reduced by 26%, 26%, and 28%, respectively compared to 3.5 g N. Nitrogen efficiency was higher when plants were fertilized with 3.5 g N regardless of LF. To maximize N absorption and minimize N losses requires a combination of maintaining an adequate N supply which is this study was 3.5 g N per 3.8 liter container in combination with a low LF.
Benefits of Community Gardening on Quality-of-Life Issues
Authors: Waliczek Tina M. , Mattson Richard H. , Zajicek Jayne M.
Published: August 2020

A nationwide survey of community gardeners found differences in rankings of the importance of community gardens related to quality-of-life perceptions based on Maslow' hierarchy of human needs model. Race, gender, and city sizes affected perceptions. When comparisons were made among the four racial/ethnic divisions, responses to 18 of the 24 questions were found to be statistically different. Community gardens were especially important to African-American and Hispanic gardeners. Male and female gardeners rated quality-of-life benefits from gardens similarly in importance. However, women placed higher value on the importance of saving money and the beauty within the garden. Gardeners in small, medium, and large metropolitan cities had similar quality-of-life perceptions with only 4 of the 24 statement responses showing significant differences. Significant differences were found in 10 of the 24 statement responses between gardeners of the two large cities of Los Angeles and New York. In most cases, mean ratings were higher for gardeners in New York than those in Los Angeles.
Propagation of Quercus myrsinifolia and Quercus canbyi by Stem Cuttings
Authors: McGuigan Patrick J. , Blazich Frank A. , Ranney Thomas G.
Published: August 2020

Stem cuttings of two clones (clone 1 and 2) of Quercus myrsinifolia Bl. (Chinese evergreen oak), and one clone of Quercus canbyi Trel. (Canby's oak), of seedling origin and in the adult growth phase, were taken on various dates representing specific growth stages. Cuttings of clone 1 of Q. myrsinifolia were collected at the semi-hardwood, hardwood, or softwood stages in addition to a transitional stage between softwood and semi-hardwood. For clone 2, stem cuttings were taken only at the softwood and transitional softwood/semi-hardwood stages. Cuttings of Q. canbyi were collected at the semi-hardwood, hardwood, or softwood stages. Cuttings of both species were treated with 0, 1500 (0.15%), 3000 (0.3%), 6000 (0.6%), or 9000 ppm (0.9%) indolebutyric acid (IBA) in 50% isopropanol. All cuttings were placed in a raised greenhouse bench and rooted under intermittent mist. Semi-hardwood or hardwood cuttings of Q. myrsinifolia or Q. canbyi did not root. Responses of stem cuttings of Q. myrsinifolia to IBA treatment varied by growth stage. For softwood cuttings response to IBA was quadratic with the greatest rooting noted for clones 1 (56%) and 2 (72%) when treated with 1500 and 3000 ppm IBA, respectively. Treatment with IBA had no effect on percent rooting of softwood/semi-hardwood cuttings of clone 1, with rooting ranging from 47% to 58%. However, a linear decrease in rooting in response to IBA was observed fordone 2 with the greatest rooting occurring for the nontreated cuttings (89%). Softwood cuttings of Q. canbyi responded quadratically to IBA treatment, with maximum rooting of 33% noted for cuttings treated with 1500 ppm IBA.
Consumer Perceptions and Expectations of Garden Center Product and Service Quality
Authors: Hudson Jay T. , Behe Bridget K. , Ponder Harry G. , Barricks William E.
Published: August 2020

We compared consumers' product and service quality perceptions and expectations from five traditional garden centers (TGC) and three non-traditional garden center outlets (NTO) in Charlotte, NC. Customers from both outlets had similar expectations of service and product quality. However, TGCs better met customer expectations with higher perceptions scores and smaller gap scores. Service quality gaps were the difference between customer perceptions and expectations. Gaps were identified for both outlets on four of five service quality dimensions and for the single product quality dimension. TGC and NTO customers ranked assurance and responsiveness as the most important service quality dimensions. Empathy was more important than reliability to TGC customers but their importance was reversed for NTO customers. Both customer groups ranked tangibles as the least important service quality dimension and retailers did not have a gap on this dimension.
The Use of Electron Beam Analysis to Determine the Deposition of Chlorothalonil Smoke Particles in a Greenhouse
Authors: Tappan C. , Krause C.R. , Powell C.C.
Published: August 2020

Electron beam analysis (EBA) was used to measure chlorothalonil smoke particles on artificial target surfaces in greenhouses. Particles between 0.4 μm (0.000016 in) and 3.0 μm in diameter were found to vary significantly in number with location within a poinsettia canopy and with distance from the source of the smoke. Particles did not vary significantly in size either within the canopy or with distance from the source. No measurable residue was found when the greenhouse was not tightly sealed. EBA proved to be a viable method of investigating fungicide smoke deposition and can provide precise information about the environmental fate of pesticides related to application technology.
Evaluation of Biological and Chemical Applications for Control of Iris Borer
Authors: Gill Stanton A. , Raupp Michael J.
Published: August 2020

Two species of entomopathogenic nematodes, Steinernema carpocapsae and Heterorhabditis bacteriophora, and two synthetic chemicals, Dimetheoate and Imidachloprid, were evaluated for suppression of the iris borer, Macronoctua onusta, on bearded iris. Field trials were conducted in prepared planting beds of bearded iris established at the Central Maryland Research and Education Center in Ellicott City, MD. Examination of larval galleries in the rhizome and number of live larvae found were used to evaluate the effectiveness of each treatment. The applications of all rates of entomopathogenic nematodes and the systemic insecticide, Imidachloprid, gave control equal to that of Dimethoate. All treatments gave significant control of iris borer compared to the control. Imidachloprid reduced borer larvae by 87% reduction; S. carpocapsae (all rates and aerated and none aerated) provided 100% control; H. bacteriophora provided 87% control; as did Dimetheoate.
Using Tree Growth Rates to Evaluate Urban Tree Planting Specifications
Authors: Neal Barbara A. , Whitlow Thomas H.
Published: August 2020

Annual growth was measured from increment cores extracted from 105 willow oaks (Quercus phellos L.) growing in seven locations in the metropolitan Washington, DC, area. Sample sites were selected to represent a range of planting specifications. In general, annual incremental growth was least in the transplant year, followed by 3–6 years of increasing growth rates that met or exceeded growth rates in the nursery. Five of the sites supported growth rates similar to open-grown trees, in a semi-natural, park-like setting, while trees growing in an irrigated, fertilized tree lawn had substantially higher growth rates. Our findings suggest that planting specifications can overcome many of the limitations to tree growth imposed by the urban environment, at least during the first 15 years following installation.
Micropropagation of Stewartia pseudocamellia
Authors: McGuigan Patrick J. , Blazich Frank A. , Ranney Thomas G.
Published: August 2020

Single-node explants were excised from shoots of actively growing, 2-year-old seedlings of Stewartia pseudocamellia Maxim. (Japanese stewartia) on three dates associated with specific stock plant growth stages. Following surface sterilization, explants were placed on agar-solidified Woody Plant Medium (WPM) containing either no growth regulators or N-(3-methyl-2-butenyl)-1H-purin-6-amine (2iP) at 5.0 or 10.0 ppm (24.6 or 48.2 μM) or 0.025 or 0.05 ppm (0.11 or 0.23 μM) N-phenyl-N-1,2,3-thiadiazol-5-ylurea (TDZ). The most frequent budbreak was noted for explants placed on media containing 2iP at either concentration. Explants cultured at the softwood stage had less contamination and greater budbreak than explants taken from more mature stem tissue. In another study, the three distal, axillary nodes of each shoot were excised at 4-day intervals for 28 days beginning 52 days after stock plants were potted following cold storage at 7C (44F). Explants were surface sterilized and placed on WPM supplemented with 10 ppm (49.2 μM) 2iP either alone or in combination with 3 ppm (8.6 μM) gibberellic acid (GA3). Neither GA3 nor node position influenced budbreak frequency or shoot elongation. Days after potting (stock plant growth stage) influenced frequency of budbreak and shoot elongation with the optimal period for explant collection being 56 to 72 days after stock plants were potted. Elongated shoots (one microcutting per explant) were produced on both media. Microcuttings ≥10 mm (0.4 in) were rooted using ex vitro procedures and acclimatized to greenhouse conditions.
Production Method and Irrigation Affect Root Morphology of Live Oak
Authors: Marshall Michael D. , Gilman Edward F.
Published: August 2020

Trees of live oak (Quercus virginiana Mill.) were container-grown (CG) or field-grown (FG) to a mean trunk diameter of 9.4 cm (3.7 in), transplanted into sandy soil, and established with frequent or periodic irrigation. Three years after transplanting, trees were harvested with a 1.5 m (60 in) diameter tree spade. Root number and root cross-sectional area was evaluated for all roots at the periphery of the tree-spade-dug root ball. Despite similar increases in trunk diameter, FG trees had greater root number and root cross-sectional area than CG trees. The greater root cross-sectional area occurred in roots 5–20 mm (0.2–0.8 in) in diameter at soil depths of 0–25 cm (0–9.8 in) and 75–100 cm (29.5–39.3 in). Irrigation frequency after transplanting had no effect on root number in FG trees. However, root number in CG trees was lower without frequent irrigation.