bluuebunny/crossref_metadata_2025 huggingface dataset:
Accelerator™ Containers Alter Plant Growth and the Root-zone Environment
Authors: Arnold Michael A. , McDonald Garry V.
Published: August 2020

Five species of trees, Fraxinus velutina Torr., Pistacia chinensis Bunge, Platanus occidentalis L., Quercus virginiana Mill., and Ulmus parvifolia Jacq., were first grown in conventional black plastic liner containers (0.45 liter, 0.41 qt) then transplanted to black plastic containers filled with 25 liters (7 gal) of substrate and grown to marketable size. The same species were grown in Accelerator liners and then transplanted to open bottom, air-root pruning, cylindrical, aluminum (Accelerator) containers filled with equal volumes of substrate. Plant growth characteristics, root-zone temperatures, and substrate moisture status were measured. As with many container technologies, responses were species dependent. Growth of Q. virginiana was reduced in Accelerator liner containers compared to conventional black plastic liners. Root coverage on the periphery of the rootballs were reduced on U. parvifolia grown in 25 liter (7 gal) containers compared to those in black plastic containers. Growth of U. parvifolia, F. velutina, and Q. virginiana were similar in the larger black plastic and Accelerator containers. Growth of P. chinensis and P. occidentalis were greater in the larger Accelerator containers than in the larger conventional black plastic containers. Root-zone temperatures, particularly at the periphery of the rootball, were significantly reduced on warm days in Accelerator containers compared to those in black plastic containers. Substrate in Accelerator containers were slightly drier than that in black plastic containers.
School Gardening: Improving Environmental Attitudes of Children Through Hands-On Learning
Authors: Waliczek Tina M. , Zajicek Jayne M.
Published: August 2020

Project GREEN (Garden Resources for Environmental Education Now), a school garden program, was integrated into the curriculum of seven elementary and junior high schools in Kansas and Texas. The objective of the study was to evaluate whether students participating in garden activities were gaining more positive attitudes about environmental issues. Students' environmental attitudes were significantly more positive after participating in the school garden program with post-test mean scores 0.26 points higher than the pre-test mean scores. Demographic comparisons indicated that female and Caucasian students, as well as students from rural areas, had more positive environmental attitudes after participating in the garden program compared to other students within each respective group.
Effect of Reclaimed Wastewater on the Growth and Nutrient Content of Three Landscape Shrubs
Authors: Gori R. , Ferrini F. , Nicese F.P. , Lubello C.
Published: August 2020

An experiment was set up to determine the effects of treated municipal wastewater irrigation and fertilization on growth, leaf morphological characteristics, chlorophyll content, and ion uptake of three container-grown landscape shrubs characterized by different growth habits (Abutilon ‘Kentish Belle’, Viburnum tinus ‘French White’, Weigelia florida ‘Bouquet Rose’). The study was conducted in Tuscany (Central Italy) in a typical landscape plant production area. One-hundred plants per species were watered with treated sewage effluent from the nearby wastewater treatment facility (RW) and 100 with well water after ponding (WW) from the nursery where the research plots were located. Fifty plants per species and within each irrigation treatment received controlled-release fertilizer application at transplant and 50 received no fertilization. The experiment showed no major limitations to the use of sprinkle-irrigated wastewater for container-grown landscape plant production and a general, positive, influence on growth of the plants. However, the species under observation showed a different behavior in response to the effluent irrigation for all the parameters considered. Weigelia was the most responsive and Abutilon the least. The influence of fertilizer addition at transplanting was less evident and the combined effect of RW and fertilization was rarely found and seemed to be species-specific.
Priming Wildflower Seed Mixtures Increases Sod Production Rate
Authors: Pill Wallace G. , Veacock Erin E. , Polston Clinton E.
Published: August 2020

Wildflower sod was established in a greenhouse by sowing primed or non-primed seeds of two seed mixtures at 2× (2.44 g/m2, 0.5 lb/1000 ft2) or 10 × (12.20 g/m2, 2.5 lb/1000 ft2) the supplier's recommended field broadcast rate onto a 2.5 cm (1 in) settled depth of commercial peat-lite (ProMix BX) contained in 28 × 52 × 5 cm (11 × 20.5 × 2 in) flats. One seed mixture (NE, Northeast) contained 54% of the species as annuals, the remainder being biennial and perennial species. The other mixture (NEANN) was a 1:1 (weight) combination of NE with a 100% annual species mixture. Seeds were primed matrically in expanded, fine-grade vermiculite for four days at −0.5 MPa at 15C (59F) in darkness (vermiculite:water:seed, 5:5:1 by wgt). At five weeks after sowing, root rating (an estimate of rooting magnitude), sod stability (an estimate of resistance to sod separation), and shoot dry weights were increased as a result of sowing primed NEANN seeds at 10×. Sod netting with 2.8 cm (1.1 in) openings, whether placed at the bottom or top of the substrate, had no effect on these variables. Sod of a duplicate, concurrent experiment was transplanted in the field at five weeks after sowing. By 12 weeks after sowing, the 10 × seeding rate increased shoot dry weight, but the effect of seed priming on shoot dry weight had been lost.
Insecticide Dips for Control of Japanese Beetle and Other Soil-Infesting White Grubs in B&B Nursery Stock
Authors: Mannion Catharine M. , McLane Win , Klein Michael G. , Nielsen David G. , Herms Daniel A.
Published: August 2020

Studies conducted in 1996, 1998 and 1999 show that immersion of root balls in Dursban® (chlorpyrifos) significantly reduces the number of white grubs, particularly Japanese beetle, Popillia japonica Newman, in B&B (ball and burlap) nursery stock. In 1996, the influence of root ball size, soil type, and dip time on the efficacy of Dursban® 50WP, Dursban® 4E, and Oftanol® 2F (isofenphos) for white grub control in dipped B&B nursery stock was evaluated. The grubs found within the root balls were primarily oriental beetle, Exomala orientalis (Waterhouse), European chafer, Rhizotrogus majalis (Razoumowsky), Asiatic garden beetle, Maladera castanea (Arrow), northern masked chafer, Cyclocephala borealis Arrow and Japanese beetle. With one exception, all the insecticide treatments caused similar grub mortality (96–100%) in 61.0 and 81.3 cm (24 and 32 in) root balls, respectively, and in sand or clay soil. There were no significant differences in grub survival due to dip time (1, 2, and 5 min). However, there were consistently fewer live grubs recovered from the root balls dipped 2 or 5 min compared with the number of live grubs recovered from root balls dipped for 1 min. In 1998, trees with 30.5, 45.7 and 61.0 cm (12, 18 and 24 in) root balls were dipped in either 0.453 or 0.906 kg ai/378.5 liter (1 or 2 lbs ai/100 gal) of Dursban® 4E for 2 mins. Both rates of Dursban® provided 100% control of Japanese beetle grubs in all three root ball sizes. Five trees from each treatment were planted one week after dipping and were evaluated for phytotoxicity up to 12 months after dipping. Most of the trees with 30.5 cm (12 in) root balls dipped in Dursban® died. Three of five trees with 45.7 (18 in) root balls dipped in the low rate of Dursban® and all five root balls dipped in the high rate had small leaves. One tree dipped in the low rate and 2 trees dipped in the high rate died 12 months after dipping. All of the trees with 61.0 cm (24 in) root balls dipped in the low rate of Dursban® survived and showed no signs of phytotoxicity. Trees with the same root ball size dipped in the high rate of Dursban® exhibited smaller leaves in 3 of the 5 trees. In 1999, trees with 61.0 cm (24 in) root balls were dipped in either 0.453, 0.226 or 0.113 kg ai/378.5 liter (1, 0.5 or 0.25 lbs ai/100 gal) of Dursban® 4E for 2 mins. All rates of Dursban® provided 100% control of Japanese beetle grubs.
Economic Impact of Florida's Environmental Horticulture Industry
Authors: Hodges Alan W. , Haydu John J.
Published: August 2020

The economic impact of Florida's environmental horticulture industry in 1997 was estimated based on a telephone survey of wholesale plant nurseries, horticultural retailers, and landscape service firms. Sales of ornamental plants and related horticultural goods and services by the production, retail, and service sectors were estimated at $1.46 billion (B), $1.75B, and $2.70B, respectively. Domestic and international exports of horticultural products and services from Florida amounted to $659 million (M). Economic multiplier effects of commercial activity associated with purchased inputs from other industries and personal consumption expenditures by employees were estimated with an input-output model. Regional impacts of the wholesale nursery sector were also estimated separately for seven areas of the state. Economic impacts of Florida's environmental horticulture industry included total value added of $5.42B and employment of 187,000 people. These impacts are greater than for any other sector of agriculture and associated manufacturing in Florida, including the large fruit and vegetable industry.
Management of Blackspot on Three Rose Cultivars Using Antitranspirants in Combination with Chlorothalonil
Authors: Roark Roland S. , Bowen K.L. , Behe B.K.
Published: August 2020

The efficacy of reducing fungicide use, by combining chlorothalonil with film-forming antitranspirant products and lengthening intervals between applications, was evaluated for control of blackspot of rose. Antitranspirants included three highly refined pine oil (pinolene) products (Nu Film 17, Vapor Gard, and Wilt Pruf) and two latex products (Stressguard and Transfilm), each of which were applied in combination with chlorothalonil fungicide. Antitranspirant solutions were applied at 2- or 3-week intervals, depending on recommended use of the antitranspirant. Blackspot severity, based on proportion of symptomatic foliage, did not differ among treatments in either year of the study. In both study years, defoliation was lower on plants treated weekly with the fungicide alone, with Stressguard (applied at 0.25% in combination with chlorothalonil every 2 weeks), or with Vapor Gard (applied at 2% in solution with chlorothalonil every 3 weeks) compared to nontreated plants. Overall, the above fungicide and antitranspirant solutions reduced season-long fungicide use by 40-69%, without a decrease in disease control, compared to the weekly chlorothalonil treatment. Plant vigor and/or growth, however, was lower with the antitranspirant treatments compared to chlorothalonil alone.
Nitrogen Nutrition of Containerized Anemone x hybrida
Authors: Dubois Jean-Jacques B. , Warren Stuart L. , Blazich Frank A.
Published: August 2020

Uniform single crown plantlets of Anemone x hybrida Paxton ‘Margarete’ were grown in 3.8-liter (#1) containers filled with a substrate of composted pine bark:sand (8:1 by vol). Plants were fertilized three times weekly for 15 weeks with a complete nutrient solution at nitrogen application rates (NARs) of 10, 40, 80, 150 or 300 mg/liter (ppm) nitrogen (N), in a constant ratio of 1 ammonium:2 nitrate. All other nutrients were held constant. Leaf area, top dry weight, and root dry weight increased with increasing NAR until reaching a plateau at a NAR of 144 ± 21 mg/liter (ppm), 158 ± 28 mg/liter (ppm), and 119 ± 30 mg/liter (ppm), respectively. The proportion of fine roots to thick roots was unaffected, and production of propagation material (root cuttings) reached a plateau at a NAR of 108 ± 28 mg/liter (ppm). Leaf concentrations of N, P, and K at maximum leaf area were 4.7%, 0.5%, and 3.5%, respectively.
Growth Regulation of Canna x generalis ‘Florence Vaughan’
Authors: Bruner L. , Keever G.J. , Gilliam C.H. , Kessler J.R.
Published: August 2020

A study conducted in 1998 and 1999 determined the effects of B-Nine (daminozide) at rates of 2500 to 7500 ppm, Pistill (ethephon) at rates of 125 to 1000 ppm, Bonzi (paclobutrazol) at rates of 33 to 99 ppm, and Cutless (flurprimidol) at rates of 50 to 150 ppm on vegetative growth and flowering of Canna x generalis ‘Florence Vaughan’ during nursery container production and landscape establishment. Vegetative height 30 and 60 days after treatment (DAT), vegetative and inflorescence heights at first flower, and vegetative height at 30 days after planting (DAP) in the landscape were reduced by Cutless in 1998 and 1999. Vegetative height was suppressed quadratically by increasing rates of Cutless, an average of 46% and 42% (1998) and 19.5% and 30% (1999) at 30 and 60 DAT, respectively. In 1998, Cutless delayed flowering one to six days, while in 1999 flowering was accelerated one to eleven days compared to untreated plants. At 30 DAP, height suppression from the lowest rate of Cutless was 5% in 1998 and 14% in 1999; however the effect was not significant at 60 DAP. With increasing rates of Bonzi, vegetative heights at 30 DAT and at first flower were suppressed 16% to 29% and 12% to 25% in 1998, respectively, but not at all in 1999. In 1998, inflorescence height at first flower decreased linearly to a maximum of 20% as Bonzi rate increased, with no effect in 1999. B-Nine did not affect vegetative or inflorescence height or flowering in 1998 or 1999, except for a three-to eight-day delay in flowering in 1998 and an one-to six-day acceleration in flowering in 1999. The only observed treatment effect of Pistill was a 9% to 17% linear height reduction at 30 DAT in 1999. B-Nine and Pistill did not exhibit effective, consistent height suppression in the 1998 or 1999 experiment and do not appear useful in controlling canna lily height.
Toxicity of Pesticides Registered for Use in Landscape Nurseries to the Acarine Biological Control Agent, Neoseiulus fallacis
Authors: Pratt P.D. , Croft B.A.
Published: August 2020

The predatory mite Neoseiulus fallacis (Garman) is an important biological control agent of spider mites in landscape plants produced in the Pacific Northwest. Using pesticide toxicity information from the SELCTV database and recent literature reports, we estimated toxicity of several general pesticide classes to N. fallacis, compared susceptibility of N. fallacis to 3 other predatory mites and developed summary tables of pesticide toxicity to N. fallacis. Pesticide classes ranged from low or non-toxic to N. fallacis (i.e., organosulfur) to highly toxic (i.e., oxime carbamate). Pesticide susceptibility data for N. fallacis within or between chemical classes was similar to data for either of Typhlodromus pyri Scheuten, Galendromus occidentalis Nesbitt, or Phytoseiulus persimilis Athias-Henriot. While all pesticide types (i.e., insecticides, fungicides, herbicides, etc.) contained representatives that were highly toxic to N. fallacis, various compounds were rated low or non-toxic. On average, insecticides were most toxic to N. fallacis, fungicides least toxic and herbicides intermediate. Probability of exposure and integration of N. fallacis into current control practices are discussed.
Use of Compost as a Media Amendment for Containerized Production of Two Subtropical Perennials
Authors: Wilson S.B. , Stoffella P.J. , Graetz D.A.
Published: August 2020

Growth of Orthosiphon stamineus (cat whiskers) and Angelonia angustifolia Benth. (angelonia) was evaluated in media containing 0, 25, 50, 75, or 100% compost (biosolids and yard trimmings mixture, 1:1, by weight). Compost was added to a commercial coir-or peat-based medium. As % compost increased, pH, electrical conductivity (EC), % nitrogen (N), and % carbon (C) increased, and the initial moisture content decreased. Orthosiphon and Angelonia growth was reduced when grown in peat or coir-based media amended with high rates of compost (75 or 100%), but flowering time was generally not affected. All plants were considered visually acceptable, except Angelonia grown in 100% compost.
Resistance of Selected Cultivars of Indian Hawthorn to Entomosporium Leaf Spot, Fireblight, and Anthracnose in Alabama
Authors: Hagan A. K. , Akridge J. R. , Bowen K. L. , Olive J. W. , Tilt K. M.
Published: August 2020

Resistance of 19 cultivars of Indian hawthorn (R. umbellata and R. × delacourii) to the diseases Entomosporium leaf spot (Entomosporiummespili), fireblight (Erwinia amylovora), and anthracnose (Colletotrichium gloeosporioides) was evaluated in a simulated landscape planting in Brewton, AL. Although symptoms of Entomosporium leaf spot were observed each year on the foliage of all cultivars, significant differences in disease severity were noted. Over the four-year test period, the lowest level of leaf spotting and premature leaf shed was consistently seen on Indian Princess® and Olivia™. Significant differences in the susceptibility of Indian hawthorn cultivars to fireblight, particularly in 1997 and 1998, were also noted. ‘Janice’ and ‘Jack Evans’, which proved particularly susceptible to this disease, resulted in the death on nearly all plants. In those same years, minor fireblight damage was also seen on Olivia™. Noticeable anthracnose-induced leaf damage and premature defoliation was recorded in 1997 only on Majestic Beauty®. Among the cultivars of Indian hawthorn screened, Indian Princess® suffered the least damage due to Entomosporium leaf spot, fireblight, and anthracnose over the four-year trial period. Olivia™ has excellent resistance to Entomosporium leaf spot but may prove sensitive to fireblight.
Variation among American Elm Clones in Long-term Dieback, Growth, and Survival following Ophiostoma Inoculation
Authors: Townsend A.M. , Douglass L.W.
Published: August 2020

Rooted stem cuttings of eight American elm (Ulmus americana L.) cultivars or selections, in addition to rooted stem cuttings of two non-American elm cultivars, ‘Prospector’ (U. wilsoniana Schneid.) and ‘Frontier’ (U. carpinifolia Gleditsch x U. parvifolia Jacq.), all planted in a randomized block, split-plot design, were inoculated on either one of two dates in May 1992 with a mixed spore suspension of Ophiostoma ulmi (Buisman) C. Nannf. and Ophiostoma novo-ulmi Brasier, the causal fungi for Dutch elm disease (DED). Crown dieback and survival were recorded once yearly for 7 years following inoculations, and height growth was measured after the sixth growing season. Analyses of variance and regression showed significant differences in disease severity among all clones tested. Among the American elms, crown dieback and mortality over time were least for ‘Valley Forge,’ ‘Princeton,’ and ‘New Harmony; ’ intermediate for ‘Delaware’ and selection R18-2; and greatest for selections 57845 and 11 and the cultivar American Liberty. Dieback and survival of ‘Prospector’ and ‘Frontier,’ the non-American elms, were comparable to that of the more disease-tolerant American elm clones. Height growth on surviving American elms for six years after inoculation was greatest for ‘Valley Forge’ and ‘Princeton’ and least for 57845, 11, and ‘American Liberty.’ Results demonstrate the ability of certain American elm cultivars and selections to respond and then recover from heavy doses of the two fungi which cause DED.
Pansy Tolerance to Preemergence Herbicides
Authors: Altland James E. , Gilliam Charles H. , Kessler J. Raymond , Wallace Elizabeth M. , Riggs Amy M.
Published: August 2020

Three studies were conducted to determine tolerance of pansy cultivars to preemergence applied herbicides. In the first two studies, three cultivars were evaluated for tolerance. In the first study plants were small at the time of treatment [5 cm (2 in) in height]. Herbicides that caused no injury or shoot dry weight (SDW) reduction of ‘Crystal Bowl True Blue’ and ‘Maxim Orange’ were Corral (pendimethalin) and Pennant (metholachlor). With ‘Imperial Antique Shades’, only Pennant 5G caused no injury or SDW reduction. In the second study, with larger transplants [12 to 15 cm (5 to 6 in) in height], the same three pansy cultivars appeared more tolerant of applied herbicides. With ‘Crystal Bowl True Blue’ only Rout 3G and Pendulum 60WDG caused injury and reduced SDW, while with ‘Maxim Orange’ those two plus Ronstar caused injury or SDW reduction. ‘Imperial Antique Shades’ again was the most sensitive cultivar with five herbicides causing injury or SDW reduction. In the third study, two cultivars, ‘Bingo’ and ‘Majestic Giant’, were treated with 11 herbicides. Corral, Treflan, and Factor caused no injury to either cultivar.
Feeding and Ovipositional Responses of Adult Elm Leaf Beetle (Coleoptera: Chrysomelidae) to Simple and Complex Asian Elm Hybrid Selections
Authors: Miller Fredric , Ware George
Published: August 2020

Nine recently developed simple and complex Asian hybrids with Ulmus davidiana, U. japonica, U. parvifolia, U. pumila, U. szechuanica and/or U. wilsoniana parentage were evaluated in no-choice laboratory bioassays for their suitability for the adult elm leaf beetle, Xanthogaleruca luteola (Müller). Suitability of each biotype was defined by the mean percentage of leaf tissue removed, the mean percentage of females ovipositing, and the mean number of eggs laid per female. Adult female beetles laid significantly more eggs on U. pumila (control) and the complex hybrid U. ‘Morton Red Tip’-Danada Charm™ indicating their greater suitability for ELB. The least suitable single and complex hybrids for adult elm leaf beetles as indicated by feeding and reproduction were U. davidiana x U. ‘ Morton’ -Accolade™ and U. szechuanica x U. japonica. Females feeding on more suitable elms oviposited 3 days earlier than females feeding on less suitable elms. Adult beetle fecundity was correlated with the length of the preovipositional period but mean percentage of females ovipositing was not correlated with length of the preovipositional period. Adult males and females lived approximately 4 days longer on the more suitable elms than on less suitable elms but adult longevity was not correlated with suitability. The percentage of leaf tissue removed by adult beetles on the different biotypes was correlated with beetle fecundity. Less suitable selections of U. davidiana x U. ‘ Morton’ -Accolade™ and U. szechuanica x U. japonica seem promising for future elm breeding programs.
Response of Lagerstroemia x ‘Tuscarora’ to Pistill and Atrimmec
Authors: Fain Glenn B. , Gilliam Charles H. , Keever Gary J.
Published: August 2020

A study was conducted in 1997, 1998 and 1999 to determine the effect of Pistill (ethephon) at rates of 333, 667 or 1000 ppm and Atrimmec (dikegulac-sodium) at rates of 723, 1446 or 2176 ppm on flower abortion, fruit set and axillary shoot stimulation of Lagerstroemia x fauriei Koehne ‘Tuscarora’ when applied at full flower. Flower abortion increased from 16.7% (1998) and 2.1% (1999) for the control to 84.2% and 64.4% respectively for Pistill (1000 ppm) at 7 days after treatment (DAT). Pistill similarly caused a significant decrease in fruit set during all three experiments with fruit set as low as 2.2% at 14 DAT in 1997 compared to 69.4% for the control. Atrimmec had no effect on flower abortion at 7 DAT in any year except 1999 with 11.3% at the 2176 ppm rate vs 2.1% for the control. Atrimmec also had little effect on fruit set except during 1998 when fruit set at 14 DAT was approximately 40% for all rates of Atrimmec compared to 65% for the non-treated control. Pistill applications resulted in more new shoots than Atrimmec in 1997, and the control in all years. Applications of Pistill at full flower can be an effective tool to abort crapemyrtle flowers resulting in reduced fruit set and increased number of new shoots
Plant Growth Retardant and Initial Plant Height Affect Canna Lily Growth and Flowering
Authors: Bruner L.L. , Keever G.J. , Kessler J.R. , Gilliam C.H.
Published: August 2020

A study conducted in 2000 determined effects of two rates of Cutless and B-Nine/Cycocel tank mix and initial plant height on vegetative growth and flowering of Canna x generalis ‘Florence Vaughan’. Canna lily responded independently to plant growth retardant (PGR) treatment and initial plant height. Cutless suppressed vegetative height consistently up to 34% at the lower rate (25 ppm) and up to 41% at the higher rate (50 ppm) throughout the study, regardless of initial plant height. At first and second flower, increasing rates of Cutless suppressed vegetative height about 36% and 35–40%, respectively, and first and second flowering heights, 39–52% and 36–47%, respectively, with minimal effect on time to flower. Height suppression from B-Nine/Cycocel treatments was less than from Cutless with the greatest suppression, 12%, occurring at first flower. Differences in vegetative height among short, intermediate, and tall plants were most significant at treatment, decreased thereafter, and were not present 60 days after treatment (DAT). The number of days to first and second flower was affected by initial plant height with shorter plants flowering 10 to 15 days later than taller plants. At first flower, vegetative height of the initially tall plants was greatest, followed in succession by plants intermediate and short at treatment. However, by second flower, vegetative heights of plants, which were initially short and intermediate in height, were greatest, followed by tall plants. At first flower, flowering heights of all plants were similar and at second flower, flowering heights of the initially tall plants were slightly less [5–6 cm (1.9–2.3 in)] than those of intermediate and short plants.
Growth Regulators and Irrigation Mitigate Competition Between Intercropped Grass and Fraxinus nigra ‘Fallgold’
Authors: Gillman Jeffrey H. , Giblin Chad P.
Published: August 2020

Grass, intercropped with nursery stock, is beneficial to the long-term productivity of a field due to decreased erosion of topsoil and increased soil organic material. The primary disadvantage of using grass as an intercrop is supposedly due to a reduction in nutrients and water available to nursery stock. In the spring of 1999, Fraxinus nigra ‘Fallgold’ trees were planted in herbicide strips with no intercrop (cultivated soil), an intercrop of untreated ryegrass, an intercrop of mowed ryegrass or an intercrop of ryegrass treated with a growth regulator. Half of the trees in each treatment were irrigated and half were not. Growth measurements were taken over two, growing seasons. There were no significant increases in growth with the addition of irrigation with the exception of trees grown with an intercrop of growth regulated ryegrass where the addition of irrigation resulted in greater tree height. Trees grown with no intercrop had the greatest increase in both caliper and height. Trees grown with grass treated with a growth regulator and irrigated did not show significantly different growth from non-irrigated trees grown without intercrops. Trees grown with untreated or mowed grass had the lowest increase in caliper and height.
Aglaonema Cultivars Differ in Resistance to Chilling Temperatures
Authors: Chen Jianjun , Henley Richard W. , Henny Richard J. , Caldwell Russell D. , Robinson Cynthia A.
Published: August 2020

Aglaonema is considered one of the most chilling sensitive tropical ornamental foliage plants. However, information on resistance of the ever-increasing number of new cultivars to chilling temperatures is not available. In this study, the chilling response of 12 Aglaonema cultivars was evaluated after exposure to 1.7, 7.2, or 12.8C (35, 45, or 55F) for 24 hours. Results showed that a high degree of genetic variation existed among the cultivars. The cultivar ‘Silver Queen’ demonstrated the greatest sensitivity to chilling with 30% of leaves injured at 12.8C (55F). In contrast, three new cultivars, ‘Emerald Star’, ‘Stars’, and ‘Jewel of India’, were the most resistant, each showing no visible injury at 1.7C (35F). Data also indicated that chilling injury to young leaves was much less pronounced than in either mature or old leaves. Additionally, chilling sensitivity of the cultivars was reduced by pre-exposure to cooler temperatures that were slightly above the chilling range.
Shoot Suppression of Lonicera × heckrottii ‘Goldflame’ (Goldflame Honeysuckle) Using Growth Retardants
Authors: Bruner L.L. , Keever G.J. , Kessler J.R. , Gilliam C.H.
Published: August 2020

A study conducted in 1999 and 2000 determined the effects of B-Nine/Cycocel (daminozide/chlormequat chloride) tank mixes at 2500/1500, 5000/1500 (1999 only), and 7500/1500 parts per million (ppm) and Cutless (flurprimidol) at 50, 100, and 150 ppm on shoot length and shoot number of pruned and non-pruned Lonicera × heckrottii ‘Goldflame’ (Goldflame honeysuckle). In 1999, B-Nine/Cycocel suppressed shoot lengths of pruned plants linearly throughout the study 18–30% 2 weeks after treatment (WAT), 16–28% 4 WAT, 24–35% 6 WAT, 24–34% 10 WAT, and 19–33% 14 WAT compared to untreated controls. Similar shoot length suppression was observed in non-pruned plants from B-Nine/Cycocel treatments in 2000 with shoots 8–24% (2 WAT), 7–24% (4 WAT), 7–20% (6 WAT), 5–19% (10 WAT), and 5–20% (14 WAT) shorter than those of untreated controls. Cutless was ineffective in suppressing shoot length of Goldflame honeysuckle in either experiment, but did increase shoot number compared to controls 6 through 14 WAT in 1999. B-Nine/Cycocel treatments did not consistently increase shoot number in either study.
Shoot and Root Growth of Three Tree Species in Sidewalks
Authors: Grabosky Jason , Bassuk Nina , Irwin Lynne , Van Es Harold
Published: August 2020

Three tree species (Tilia cordata Mill. ‘Olympic’, Acer campestre L., and Malus sp. Mill. ‘Adirondack’) were grown in a standard sidewalk pavement profile, an experimental sidewalk profile (SSM), and in the field. Root systems in the paved treatments were harvested after three years to analyze root length, root density, and profile distribution. SSM tree foliage quality (measured by SPAD 502) and shoot extension measured in the second and third years were not different than those of the field control trees. Tree foliage quality and shoot extension were reduced in the standard sidewalk profile. There was an increase in root length of Acer and Tilia in the SSM profile versus the standard sidewalk profile and an increase in depth of the root zone for all species. The results indicate several advantages in root and canopy growth for street trees grown in the experimental profile compared to the standard sidewalk pavement profile.
Seed Source Effects on Growth and Flowering of Coreopsis lanceolata and Salvia lyrata
Authors: Norcini Jeffrey G. , Aldrich James H. , Martin Frank G.
Published: August 2020

Coreopsis lanceolata L. and Salvia lyrata L. from local (Monticello, FL) and nonlocal seed sources were transplanted into a field and maintained under low input, noncompetitive landscape conditions for 2 years. Plants of both species from local seed sources began flowering and were in full bloom earlier than plants from the nonlocal seed sources. Nonlocal C. lanceolata were larger throughout the study. Local S. lyrata were taller than nonlocal plants only when local plants were in flower and nonlocal plants were not. Survival percentage of C. lanceolata was equivalent from both seed sources, but higher for local S. lyrata compared to nonlocal, at the conclusion of the study.
Seasonal Variations of Foliar Nutrients in Green and Chlorotic Red Maples
Authors: Steven Messenger A.
Published: August 2020

Foliar samples from green and chlorotic red maple trees (Acer rubrum L.) were collected during each of three periods of the growing season, and analyzed for nutrient element concentrations. Compared to green leaf nutrient concentrations, those in chlorotic leaves were statistically different as follows: high P and K, and low Mn in late spring; high N, P, K, Fe, and Zn, and low Mn in mid-summer; high K and Mg, and low Mn in late summer. Considering lowest individual nutrient concentrations per period in green leaves as critical values, most chlorotic leaves were deficient in Mn, a few were deficient in Cu or Zn, and none was deficient in Fe. Using a similar method for identifying excesses, most chlorotic leaves contained excessive K, accompanied by excessive P in mid-summer. Chlorotic leaves with no apparent micronutrient deficiencies were excessively high in some individual or combination of macronutrients, primarily K, but consistently accompanied by P in mid-summer.
Growth Response of Acer grandidentatum Nutt. to Chilling Treatments
Authors: Sorenson E. , Williams C.F. , Walser R.H. , Davis T.D. , Barker P.
Published: August 2020

The response of dormant canyon maple (Acer grandidentatum Nutt.) seedlings to chilling was investigated. The most rapid, uniform bud break occurred after the plants were chilled for 1,000 or 1,500 hours at 5°C (41 °F). Plant height and caliper were also greater for chilled plants than unchilled controls. These results suggest that A. grandidentatum production can be accelerated by alternately growing the plants in a greenhouse until growth ceases and then chilling them for at least 1,000 hours to overcome rest.
Effect of Incorporating Controlled-release Fertilizer on Adventitious Rooting and Growth of Artemisia, Gaura, and Nepeta
Authors: Rowe D. Bradley , Cregg Bert M.
Published: August 2020

Controlled-release fertilizer was incorporated into the rooting substrate to determine its effect on adventitious rooting and subsequent growth of three herbaceous perennials: Artemisia ludoviciana ‘Valerie Finnis,’ Gaura lindheimeri ‘Whirling Butterflies,’ and Nepeta x faassenii ‘Six Hills Giant.’ Nutrient treatments consisted of a control, and four treatments each of Nutricote® 13–13–13 Type 180 and 18–6–8 Type 180 at 3, 6, 9, and 12 g/liter (5, 10, 15, and 20 lbs/cu yd) incorporated into the rooting substrate. These treatments equate to N rates of 0, 0.38, 0.77, 1.16, 1.54, 0.53, 1.07, 1.6, and 2.13 g/liter (N at 0, 0.65, 1.3, 1.95, 2.6, 0.9, 1.8, 2.7, and 3.6 lbs/cu yd), respectively. Incorporating controlled-release fertilizer into the rooting substrate at levels equal to or greater than 0.77 g/liter (1.3 lbs/cu yd) increased shoot dry weights, but had no effect on adventitious rooting and little influence on root number or root dry weight. This in turn influenced shoot:root ratios and potentially plant quality. There was no difference between the two formulations.
Photosynthesis and Shoot Health of Five Birch and Four Alder Taxa After Drought and Flooding
Authors: Graves William R. , Kroggel Mark A. , Widrlechner Mark P.
Published: August 2020

Selection of under-used taxa of birches (Betula L.) and alders (Alnus Miller) for use in managed landscapes can be guided by information on their responses to moisture extremes in the root zone. Our objective was to compare the photosynthesis, leaf surface area, and subjective health ratings of eight relatively obscure birches and alders when treated with drought and flooding in a greenhouse. We also treated ‘Whitespire Sr.’ birch (Betula populifolia) to demonstrate responses of a cultivar common in the nursery trade. Plants used as controls were irrigated daily, whereas pots of flooded plants were immersed. All water was withheld from the drought-treated taxon that showed the least evapotranspiration each day, while amounts of water less than that lost to evapotranspiration each day were added to plants of the other taxa subjected to drought. After three cycles of drought that induced wilting and a reduction in photosynthetic rate, leaf surface area of A. hirsuta had decreased the least, 12%, among the alders. While drought reduced the photosynthesis of all birches during the study, mean photosynthetic rate of drought-treated B. uber was higher than that of B. albosinensis and B. davurica subjected to drought. Flooding for 7 days did not influence photosynthetic rate of any alder but reduced photosynthesis of all the birches except B. davurica. After 21 days of flooding, only plants of B. albosinensis and B. costata were killed, and A. maritima was the only alder that fully sustained photosynthesis. While our data support the idea that most alders and birches are adapted to wet and well-drained sites, respectively, responses to drought varied among the four alders, and the four uncommon birches we grew responded differently to flooding. Specifically, additional evaluations under field conditions should be done to confirm the resilience of A. hirsuta and A. maritima to recurrent drought and to verify whether the comparatively promising (B. davurica and B. uber) and poor (B. albosinensis and B. costata) flood resistance we observed among the birches is meaningful in the landscape.
Use of Fluorescent-Amplified Fragment Length Polymorphism for Species Identification in the Genus Pulmonaria
Authors: Zhou Suping , Sauve Roger J.
Published: August 2020

The species identity of ‘Roy Davidson’, a popular commercial cultivar in the genus Pulmonaria, is uncertain. To determine to which species ‘Roy Davidson’ is related to, we used fifteen primer combinations for Fluorescent-Amplified Fragment Length Polymorphism (F-AFLP) analysis. UPGMA dendrograms generated from AFLP markers obtained from the primer combinations showed that ‘Roy Davidson’ shares more genetic information with P. longifolia than with P. saccharata. Several factors that can affect F-AFLP profiles (DNA isolation from leaf tissue, optimization of F-AFLP procedures, and the use of this method for genotyping pulmonarias) were also evaluated; the results are discussed in this paper.
Tolerance of Supina Bluegrass to Pre and Post-Emergence Herbicides
Authors: Steinke Kurt , Stier John
Published: August 2020

Supina bluegrass (Poa supina) is being increasingly used for shaded lawns and golf course tees due to its excellent shade tolerance. The herbicide tolerance, however, is undocumented because herbicide use on amenity turfs is banned in the European countries where supina bluegrass has been used for over 30 years. Several commonly used turf and ornamental herbicides are capable of harming or eradicating close relatives of supina bluegrass. In particular, Prograss (Ethofumesate) is used to selectively remove annual bluegrass (Poa annua) from mixed turf stands. Supina bluegrass is a putative ancestor of annual bluegrass and may have similar susceptibilities to chemicals. Fifteen pre and postemergence turf and ornamental herbicides were tested for their potential to damage or kill a mature stand of supina bluegrass. Field trials were conducted twice over two growing seasons. Herbicides with the active ingredients triclopyr, MCPP, quinclorac, and ethofumesate caused temporary phytotoxicity in at least one of the two years. Fall applications of Prograss (Ethofumesate) and Turflon Ester (Triclopyr) caused phytotoxicity the spring following autumn application in both years, while Strike 3 (Dicamba, MCPP, 2,4-D) and Confront (Triclopyr + Clopyralid) caused phytotoxicity in one year only. None of the compounds showed potential for selectively removing supina bluegrass from a mixed turf stand.
Abundance of Beneficial Arthropods on Woody Landscape Plants at Professionally-Managed Landscape Sites
Authors: Stewart Colin D. , Braman S. Kristine , Sparks Beverly L.
Published: August 2020

Eight 0.2–0.4 ha (0.5–1.0 A) sites managed by landscape professionals were monitored biweekly for beneficial arthropod activity. More than 30 generalist predator taxa were identified. Spiders and green lacewings were the most numerous taxa and both were found on all plant taxa sampled. Green lacewings, especially the egg stage, were the most numerous natural enemies detected on birch, crape myrtle, cherry, and oak trees accounting for 52.5, 49.9, 43.5, and 38.1%, respectively. Spiders accounted for 56.2% of the insectivorous arthropods observed on magnolia and were the most abundant predatory arthropod on azaleas comprising 46.5% of all arthropod predators/parasites across all properties. The most abundant predatory arthropods on junipers were spiders accounting for 75.5% of the beneficials encountered with ants (associated with an early season aphid outbreak), green lacewing larvae, lady beetles, harvestmen, and parasitic wasps comprising 15.8, 0.4, 4.3, 0.4, and 1.2%, respectively. Spiders were the most abundant predators on boxwood accounting for 70.6% of the natural enemies.
Suitability and Feeding Preference of Selected North American, European, and Asian Elm (Ulmus spp.) Biotypes to Elm Leaf Beetle (Coleoptera: Chrysomelidae)
Authors: Miller Fredric , Ware George
Published: August 2020

Recently introduced North American elm cultivars, simple and complex elm hybrids of European and Asian parentage, and simple Asian hybrids of U. pumila and U. japonica parentage growing at The Morton Arboretum, Lisle, IL, were evaluated in laboratory bioassays for ovipositional response, and feeding preference and suitability for larvae and adults of the elm leaf beetle, Xanthogaleruca luteola (Muller). Larval and adult no-choice and adult multiple-choice feeding studies revealed that the North American cultivars of U. americana ‘Jefferson’ and U. americana ‘Valley Forge’, U. americana (diploid form), and U. americana were the least preferred for feeding and reproduction by the elm leaf beetle. Among simple and complex European hybrids, ‘Homestead’, ‘Patriot’, and ‘Prospector’ were least preferred and least suitable for larval development, feeding, and reproduction by adult elm leaf beetles. Hybrids of ‘Frontier’, ‘Pioneer’, and ‘Regal’; the simple Asian hybrids of ‘Cathedral’ and ‘New Horizon’; and U. pumila were more highly preferred for feeding and suitable for reproduction. The least preferred and least suitable North American biotypes of U. x americana ‘Jefferson’, U. americana ‘Valley Forge’, and U. americana (diploid form), simple and complex European hybrids of ‘Homestead’, ‘Patriot’, and ‘Prospector’, show promise for use in areas where the elm leaf beetle is persistent and for future elm breeding programs.
Cold Hardiness Potential of Ten Hydrangea Taxa
Authors: Adkins Jeffrey A. , Dirr Michael A. , Lindstrom Orville M.
Published: August 2020

Nine Hydrangea macrophylla (Thunb.) Ser. and one H. serrata (Thunb. ex J.A. Murr.) Ser. cultivars were evaluated for midwinter cold hardiness, acclimation, and deacclimation to identify cultivars with increased cold tolerance. Hydrangea macrophylla ‘Endless Summer’, ‘Mariesii Variegata’, and ‘Veitchii’ acclimated later than all other cultivars. ‘Générale Vicomtesse de Vibraye’ acclimated first, and was cold hardy to −6C (21F) by September 28, 2000. The greatest cold hardiness in all cultivars occurred on January 5, 2001. Maximum cold tolerance in all cultivars was within a 6C (11F) range with ‘Endless Summer’ being the least cold hardy [−18C (0F)], while ‘Dooley’, ‘Générale Vicomtesse de Vibraye’, ‘Mme. Emile Mouillère’, and H. serrata ‘Bluebird’ possessed the greatest cold hardiness [−24C (−11F)] on January 5. Deacclimation in all cultivars began after the January 5 collection date as indicated by the February 1, 2001, data. On March 1,2001, ‘Ayesha’ and ‘Mariesii Variegata’ survived only 4C (39F) while all other cultivars survived at least −6C (21F).
Propagation Time Affects Winter Survival and Finishing Date for Ornamental Grasses
Authors: Cunliffe Bruce A. , Meyer Mary Hockenberry
Published: August 2020

Five grasses: little bluestem, Schizachyrium scoparium (Michx.) Nash; prairie dropseed, Sporobolus heterolepis (A. Gray) A. Gray; feather reedgrass, Calamagrostis x acutiflora (Schrad.) DC. ‘Karl Foerster’; redflame miscanthus, Miscanthus Anderss. ‘Purpurascens’; and variegated Japanese silvergrass, Miscanthus sinensis Anderss. ‘Variegatus’; were propagated in fall and spring by plugs or field divisions into 480 ml (4 in round), 2.7 liter (#1), or 6.2 liter (#2) nursery containers. Plants were evaluated for finish date and winter survival. Three fall handled species consistently finished as a salable plant within one year: Schizachyrium scoparium plugs, Calamagrostis xacutiflora ‘Karl Foerster’ divisions, and Miscanthus ‘Purpurascens’ divisions. Sporobolus heterolepis and Miscanthus sinensis ‘Variegatus’ grew faster and finished with significantly higher survival rates from spring divisions. Spring planted plugs of S. heterolepis and S. scoparium finished within 9 weeks. The two smaller container sizes finished significantly ahead of the larger size.
Compost Effects on Soil Chemical Properties and Field Nursery Production
Authors: Gonzalez Ronald F. , Cooperband Leslie R.
Published: August 2020

Field production of ornamental shrubs results in significant topsoil removal and degradation of soil chemical properties. We amended field soils with compost to evaluate effects on soil chemical properties and shrub biomass production. We applied either duck manure-sawdust (DM), potato cull-sawdust-dairy manure (PC) or paper mill sludge-bark (PMB) composts to a silt loam soil as a) incorporated 2.5 cm (1 in) of compost tilled into the top 15 cm (6 in) of soil or b) incorporated + mulched 2.5 cm (1 in) tilled into soil + 2.5 cm (1 in) applied over the soil surface. We grew Spirea japonicum ‘Gumball’, Juniper chinensis ‘Pfitzeriana’ and Berberis thunbergia ‘Atropurpurea’ seedlings and measured total and plant available nutrients and shrub biomass production and nutrient contents over two growing seasons. Total soil C was 15–21% higher in all mulched treatments compared to incorporated-only and no-amendment control treatments. Total soil N, P and Cu, available P, S, Ca, Mg, K, pH and EC increased with increasing TC. Mulched DM compost produced significantly higher DTPA-extractable Zn relative to other treatments. In the second growing season, mulched DM compost produced 39–42% greater total barberry biomass than all other treatments. Among all shrub species, the best soil chemical predictors of plant growth were TC, TS, soluble P, exchangeable Ca and K and DTPA-Zn. The best tissue nutrient-content predictors of plant growth were total shoot N, P and Zn and root Zn. The unique growth response of barberry to mulched DM compost suggests that all shrubs may not respond to compost amendments, particularly over the short term.
Effect of Seed Scarification and Gibberellic Acid Treatment on Seedling Emergence of Sky-Blue Lupine (Lupinus diffusus)
Authors: Dehgan Bijan , Norcini Jeffrey G , Kabat Steven M. , Pérez Hector E.
Published: August 2020

The efficacy of various scarification treatments and gibberellic acid (GA3) treatment on seedling emergence of Lupinus diffusus Nutt. (sky-blue lupine) was evaluated. Seed scarified in concentrated sulfuric acid for 90 min followed by immersion in water for 24 hr resulted in the best emergence of viable seed (≈ 41%). Mechanical scarification with sandpaper for up to 30 min did not improve seedling emergence. Immersing seed in 90C (194F) water which was then allowed to cool for 24 hr apparently killed or severely injured the embryos as no seedlings emerged from seeds treated with hot water. There was only 5% seedling emergence for nonscarified seed that were soaked in water at room temperature for 24 hr. Emergence was not improved by soaking scarified seed in 1000 mg/liter (ppm) GA3 for 24 hr prior to sowing the seeds.