bluuebunny/crossref_metadata_2025_split huggingface dataset:
Screening Potential New Tropical Ornamentals for Alkalinity, Salinity, and Irradiance Tolerances
Authors: Arnold Michael A. , McDonald Garry V. , Denny Geoffrey C. , Carver Sean T. , King Andrew R. 
Published: August 2020

Abstract
With the rapid introduction of new herbaceous or woody perennial tropical and subtropical taxa to the U.S. nursery trade for use as summer annuals, methods for quickly assessing their tolerances to various environmental stresses will be needed. Three screening methods, one each for substrate alkalinity, soil salinity, and varied irradiance levels, were tested on four tropical taxa, Rotheca myricoides (Hochst.) Steane & Mabb. (blue butterfly bush), Graptophyllum pictum (L.) Griff, (caricature plant), Jatropha integerrima Jacq. (firecracker jatropha), and Chrysothemis pulchella (Don. ex J. Sims) Desc. (dozakie), with potential for use as summer annuals. Specialized portable structures for testing irradiance levels were developed which minimized confounding of restricted air movement often associated with imposing shade treatments. Irradiance and salinity screening procedures were deemed successful, while further refinement is needed with the alkalinity screening method tested. Decreased irradiance levels suppressed flowering of R. myricoides, while full sun exposure decreased foliar appearance and growth of C. pulchella. Only J. integerrima showed adverse responses to elevated substrate alkalinity. Jatropha integerrima and G. pictum exhibited adaptation to a wide range of light exposures and salinity levels while maintaining attractive foliage. Although flowering of J. integerrima was reduced with heavy shade (66%), some flowering continued.
Fresh Recycled Mushroom Compost Suppresses Artillery Fungi Sporulation: A 4-Year Field Study
Authors: Davis Donald D. , Fidanza Michael A. 
Published: August 2020

Abstract
Artillery fungi (Sphaerobolus spp.) have recently emerged from an interesting mycological curiosity that grow in landscape mulch, to a problem of emotional stress and financial concern to homeowners, as well as insurance companies, mulch producers, and landscape contractors. Artillery fungi shoot their spore masses (gleba) towards sunlight and/or reflective objects such as light-colored house siding or automobiles, peppering the surface with small sticky tar-like black specks. Once dry, gleba are very difficult to remove from surfaces such as vinyl siding. If they can be removed, gleba usually leave a brown stain that is extremely difficult to clean. We previously reported that aged (weathered or composted outside) mushroom compost (MC), when blended with landscape mulch at ≥ 40% by volume, suppressed artillery fungi sporulation in the mulch. In this paper, we report that fresh MC, taken directly from the mushroom house and blended with landscape mulch without aging, also reduces artillery fungi sporulation as follows: 0% MC (control = 0% reduction), 10% MC (62%), 20% MC (80%), 40% MC (95%), and 100% MC (97% reduction in sporulation). Landscape companies using fresh MC, rather than aged MC, need not invest time and money in additional MC aging, composting, and processing.
Susceptibility of Eastern Ninebark (Physocarpus opulifolius (L.) Maxim.) Cultivars to Powdery Mildew
Authors: Lubell J.D. , Brand M.H. , Lehrer J.M. 
Published: August 2020

Abstract
Powdery mildew disease severity was assessed on ten eastern ninebark (Physocarpus opulifolius (L.) Maxim.) cultivars. The green foliage cultivar ‘Nanus’ was resistant to powdery mildew. Among the deep purple foliage cultivars, ‘ Seward’ Summer Wine® exhibited better resistance than ‘Monlo’ Diablo® and was nearly as resistant as ‘Nanus’. ‘Seward’ Summer Wine® is a hybrid between ‘Nanus’ and ‘Monlo’ Diablo® and probably derives its mildew resistance from ‘Nanus’. ‘Monlo’ Diablo® had reasonably good mildew resistance. Yellow foliage cultivars ‘Dart's Gold’, ‘Morning Star’ and ‘Nugget’, which were highly susceptible to powdery mildew, were unattractive due to substantial leaf drop, leaf disfigurement and shoot brooming. ‘Luteus’ exhibited better powdery mildew resistance than the other yellow foliage cultivars. ‘Mindia’ Coppertina® and ‘Center Glow’, two recent purple foliage introductions with orange-copper new foliage, exhibited levels of mildew intermediate between purple and yellow foliage cultivars. These ‘Monlo’ Diablo® × ‘Dart's Gold’ hybrids probably owe their reduced mildew resistance to their ‘Dart's Gold’ lineage.
Influencing Public Perception of Sustainable Roadside Vegetation Management Strategies
Authors: Lucey Anne , Barton Susan 
Published: August 2020

Abstract
Sustainably managed roadsides limit non-native turf grass and include meadows of native warm season grasses and flowering perennials, native shrubs, and trees. Implementation of sustainable strategies result in cost savings, better water quality and infiltration, increased diversity of insect life and benefits to the socioeconomic health of the state. Lacking an awareness of associated benefits, the public is often hesitant to accept sustainable, but less manicured roadsides, causing many Departments of Transportation to revert to traditional management regimes. This research assessed perception and determined that acceptance could be increased with an awareness of associated benefits. An Internet survey was administered to three groups of participants. A control group rated eleven roadside images from least to most desirable and completed a brief survey. An experimental group read a list of information about traditional and sustainable strategies of roadside vegetation management before rating the images and completing the survey. Another experimental group viewed a 6½ minute video that delivered the same information as the list, but engaged the respondent differently. This group then rated the images and completed the survey, as did the previous two groups. Among those who read the list, a significant change in perception occurred for three of the images when compared to those in the control group. Among those who viewed the video, a significant change in perception occurred for four of the images when compared to those in the control group. When all images were compared to the baseline image (mown turf), Delaware's current default vegetation management strategy, each response distribution was significantly different than that of mown turf. Respondents rated images of flowering meadows, meadow with a mown turf margin, turf with a wooded edge, shrubs and trees more desirable than mown turf and images with grassy meadows less desirable. When strategies were grouped according to similar attributes and compared to mown turf, respondents rated images with flowers (flowering meadows, shrubs and trees), and images with a mown turf margin more desirable than turf and grass meadows less desirable.
Reduced Use of Pesticides for Effective Controls of Arthropod Pests and Plant Diseases
Authors: Zhu Heping , Zondag Randall H. , Krause Charles R. , Merrick Jim , Daley Jay 
Published: August 2020

Abstract
Current label recommendations of pesticides for arthropod pests and plant diseases in the nursery and green industry are vague and frequently result in excessive pesticide use. The objective of this research was to demonstrate that modifications of spray application techniques with current spray equipment in ornamental nursery production could reduce pesticide use. The efficacy of half rates and full rates of both active ingredients and carrier was investigated in commercial nurseries with air-assisted sprayers in two tests and a state inspector survey for the control of arthropod pests and plant diseases. Sprayers were optimized with properly sized nozzles and properly calibrated operating parameters. In Test 1, treatments were conducted in approximately 0.5 ha (1.2 A) plot each in three commercial nurseries for control of arthropod pests and diseases, and in Test 2, the same treatment for aphid control was evaluated in a birch tree plot. The survey was a compilation of the pests and diseases that were diagnosed by state inspectors in over 2,800 plant varieties and species from two commercial nursery fields [total about 280 ha (692 A)] after the spray treatments in six growing seasons. Crop damage by 49 insects and 40 diseases were surveyed for different application rates. The studies revealed that insect and disease control using 50% of the label rates was as effective as full rates when quality spray coverage on targets was achieved, resulting in real cost benefits to producers, consumers and the environment.
Low-Value Trees as Alternative Substrates in Greenhouse Production of Three Annual Species
Authors: Murphy Anna-Marie , Gilliam Charles H. , Fain Glenn B. , Allen Torbert H. , Gallagher Thomas V. , Sibley Jeff L. , Boyer Cheryl R. 
Published: August 2020

Abstract
Peat and perlite have served as industry standards in greenhouse substrates for over 50 years. The continued availability of peat, paralleled with its inert characteristics, as well as its ability to stay generally pathogen-free have all contributed to its success in the horticulture industry. Expanded perlite has long been used as an amendment in container mediums to provide air space to container substrates without adding to bulk density or affecting substrate pH and EC. However, due to increased restrictions on the harvesting of peat, as well as fluctuations in fuel prices necessary for shipping, the future availability of peat is a largely unknown factor in greenhouse production. Additionally, growers consider perlite to be a general nuisance due to the lung and eye irritation problems. Because of these problems, researchers have focused on identifying and evaluating possible alternatives to standard substrates. These studies evaluated three possible substrate alternatives for use in greenhouse production, including fresh sweetgum (SG), hickory (H), and eastern redcedar (RC), in addition to WholeTree (WT) substrate. Three greenhouse annual crops (petunia, impatiens, and vinca) were planted in varying ratios of these species mixed with peat. Plants grown with SG and H as amendments did not perform as well as a traditional peat:perlite mix with respect to flower number, growth indices, and plant dry weight. However, plants grown in RC tended to be equivalent to those grown in a traditional mix. Data showed that greenhouse producers could amend their standard greenhouse substrate with up to 50% eastern redcedar with little to no differences in plant growth.
Using Simple Sequence Repeats (SSRs) to Measure Pollen Flow in a Flowering Dogwood Orchard
Authors: Rhoades Paul , Wadl Phillip A. , Klingeman William E. , Trigiano Robert N. , Skinner John 
Published: August 2020

Abstract
Dispersal of flowering dogwood pollen in an orchard was evaluated by performing parentage analyses on open pollinated seedlings collected from a single maternal tree. Pollen sources for 45 seedling trees were established using three polymorphic simple sequence repeat (SSR) loci. Previous data suggest that Cornus florida pollen is typically limited to travel between closely situated trees. If this is true, breeding may be simplified by crossing trees through open pollination rather than more laborious current methods involving pollination cages. However, the expected leptokurtic distribution, in which the likelihood that pollen transfer will occur between trees decreases quickly as distance increases, was not seen. Although the majority of paternal trees were located within the 12 m (39.4 ft) radius of the study area, the trees most likely to have donated pollen were some of those located the greatest distance from the mother tree. Unusual pollen movement may be explained, in part, by asynchronous flowering times of trees within the study or by genetic similarities exhibited between the mother tree and potential pollen donors in the area. Additionally, andrenid and halictid bees, which were the predominant pollinators observed at this site, may have moved pollen farther than expected.
Management of Powdery Mildew on Flowering Dogwood with Soybean Oil
Authors: Deyton Dennis E. , Sams Carl E. , Cannon Adrianna L. , Cummins John C. , Windham Mark T. 
Published: August 2020

Abstract
Soybean oil formulations developed in our laboratory were evaluated for control of powdery mildew on flowering dogwood Cornus florida. In a preliminary trial in a field nursery, two formulations, TNsoy1 and TNsoy2 [0, 1 or 2% (v/v)], were applied to field-grown flowering dogwood at 2 wk intervals from June 10 until August 19. Soy oil-treated trees had less powdery mildew, higher net photosynthetic rate and growth rate than unsprayed trees, without apparent phytotoxicity. Leaves sprayed with Banner MAXX had less powdery mildew and higher photosynthetic rates than oil treated leaves. These same treatments applied the next year under more frequent rain showers did not provide satisfactory control. Newer soybean oil formulations using natural or food grade emulsifiers, were compared to three commercial botanical oil formulations and to SunSpray Ultra Fine Oil in greenhouse trials. All oil formulations provided some protective and eradicative control of powdery mildew. Photosynthesis of oil treated leaves was usually depressed, compared to controls, for several days but recovered. In greenhouse trials where the oil was not washed off by rain or irrigation, the oil residue was visible on leaves, reduced powdery mildew severity, and depressed photosynthesis for several weeks. In a second greenhouse trial, soybean oil formulations provided greater control if applied after rather than before initial inoculation.
Nitrogen Form Affects pH and EC of Whole Pine Tree Substrate and Growth of Petunia
Authors: Witcher Anthony L. , Fain Glenn B. , Blythe Eugene K. , Pounders Cecil T. 
Published: August 2020

Abstract
Wood-based substrates are potential alternatives or amendments to traditional peat-based and pine bark substrates. Undesirable changes in substrate pH may result from the application of supplemental fertilizer required by some crops grown in wood-based substrates. Experiments were conducted to evaluate petunia growth and substrate pH in response to nitrogen (N) treatments applied as a nutrient solution to whole pine tree (WPT) and peat-lite (PL) substrates. Nitrogen treatments were applied as 100% ammonium (NH4+ N), 100% nitrate (NO3−N), or a combination of both in various proportions. The pH range of WPT substrate widened considerably over time among the N treatments, while a change in substrate pH was minimal for PL substrate during the same period. Generally, 100% NO3−N and 100% NH4+ N resulted in the highest and lowest substrate pH, respectively, regardless of substrate. Greater shoot dry mass was obtained in PL substrates compared with WPT substrates. Maximum shoot dry mass and flower count with ‘Celebrity Rose’ petunia were obtained with the mixed N-form treatments in both substrates. Greater substrate air space and total porosity was associated with WPT substrates compared with PL substrates, the latter having greater container capacity.
Landscape Establishment for Baldcypress, Red Maple, and Chaste tree is Delayed for Trees Transplanted from Larger Containers1
Authors: Chance Lauren M. Garcia , Arnold Michael A. , Lombardini Leonardo , Watson W. Todd , Carver Sean T. , King Andrew R. 
Published: August 2020

Abstract
With container-grown trees offered to the public in an increasing array of sizes, it is important to determine the effects of different sizes of container stock on transplant establishment. Clonal replicates of Vitex agnus-castus, Acer rubrum var. drummondii, and Taxodium distichum grown under common nursery conditions in five container sizes, 3.5, 11.7, 23.3, 97.8, or 175.0 L (#1, #3, #7, #25, or #45, respectively), were transplanted to a sandy clay loam field. Physiological stress was measured using xylem water potential and photosynthetic gas exchange rates. Height, trunk diameter, and canopy spread were monitored post-transplant for three growing seasons and root growth was sampled for the first two growing seasons. Trees of all three species from smaller-sized containers, 23.3 L (#7) or less, exhibited reduced transplant shock, decreased establishment time and increased growth rates in comparison to larger-sized containers, apart from increased mortality in 3.5 L (#1) A. rubrum and slower growth in 3.5 L (#1) T. distichum compared to those transplanted from 11.7 L (#3) or 23.3 L (#7) containers Reduced stress levels and increased growth rates corresponded in timing with greater change in root extension of smaller container-grown trees. At the end of three growing seasons, no statistical differences in height or trunk diameter were present for V. agnus-castus container sizes. With a modest wait, consumers may find that smaller container-grown trees will overcome transplant stress more quickly and exhibit growth rates that surpass those of larger container-grown trees.
Index words: Acer rubrum, Taxodium distichum, Vitex agnus-castus, container-grown trees, transplant shock, transplant establishment, photosynthesis, transpiration, water stress.
Species used in this study: Chaste tree (Vitex agnus-castus L. [an unnamed white flowering clone]); red maple (Acer rubrum L. var. dummondii [Hook. & Arn. ex Nutt.] Sarg. ‘Maroon'); bald cypress (Taxodium distichum (L.) Rich. [test clone TX8DD38]).
Evaluating Impacts of Brown Marmorated Stink Bug on Non-fruiting Nursery Crops1
Authors: Skillman Victoria P. , Lee Jana C. 
Published: August 2020

Abstract
Halyomorpha halys (Stål), the brown marmorated stink bug or BMSB, has become a major pest and nuisance since it arrived in the U.S. in 1996. This insect can feed on approximately 200 different plant species, many of which are important ornamental crops. BMSB's preference for fruits and the damage they cause is known, but it is not known how their presence on non-fruiting woody ornamentals can impact vegetative growth. The first study confined adult BMSB to branches of established stock block trees of five plant species for one month. Four measurements were taken to assess plant growth: branch length, leaf area, number of leaves, and dry weight. The second study confined adult BMSB on seedlings of eight plant species for one or two months. In this study, the same four measurements were taken as well as the change in trunk diameter. Overall, there were no significant differences in plant growth and only some marginal differences between branches or seedlings caged with BMSB versus no BMSB (control) after one or two months. Adults laid eggs on all plants species in both trials, and nymphs were observed to develop to the 2nd instar stage in the seedling trial on all the plant species except for maple. Confinement of BMSB on branches of well-established nursery plants or on newly planted seedlings had little or no impact on growth over a two month exposure.
Index words: Halyomorpha halys, Hemiptera, ornamentals, seedling, vegetative growth.
Species used in this study: Brown marmorated stink bug (Halyomorpha halys Stål); Dolgo crabapple (Malus sp.); Yoshino cherry (Prunus yedoensis Matsum.); Japanese elm (Ulmus davidiana Planch.); Siberian elm (Ulmus pumila L.); Ginkgo (Ginkgo biloba L.); Washington hawthorn (Crataegus phaenopyrum (L.f.) Medik); lsquo;Ivory Silk' lilac (Syringa reticulata Blume); ‘Green Mountain' silver linden (Tilia tomentosa Moench); ‘Crimson Sunset' maple (Acer truncatum Bunge); ‘Franksred' maple (Acer rubrum L.)
Effects of a Nonionic Surfactant on Growth, Photosynthesis, and Transpiration of New Guinea Impatiens in the Greenhouse1
Authors: Sibley Jeff L. , Yang Xiaomei , Lu Wenliang , Eakes D. Joseph , Gilliam Charles H. , Foshee Wheeler G. , Pickens Jeremy M. , Zinner Bertram 
Published: August 2020

AbstractProduction of quality greenhouse and nursery crops is dependent on high quality and quantities of water. At present, in some regions, insufficient water supply is a growing concern. This study was conducted to evaluate growth of New Guinea impatiens (Impatiens hawkerii 'Celebrate Salmon'), when watered with a polyoxyethylenesorbitan monolaurate (C58H114O26) solution commercially known as Tween 20, at differing irrigation levels compared with a conventional water regimen without the surfactant, and also to determine how Tween 20 would affect photosynthesis and transpiration. The treatment design was a 3 by 6 complete factorial design plus a control. The two factors were irrigation and Tween 20. Irrigation levels of 20%, 40%, or 60% of the full crop evapotranspiration (ET) requirements were used in combination with Tween 20 concentrations of either 0, 25, 50, 75, 100, or 125 mg·L−1 (0, 0.003338, 0.00668, 0.0100145, 0.01335, or 0.01669 oz per gallon). The control group was watered with tap water to container capacity with about 30% leachate. Evapotranspiration was determined as the difference of the applied water amount minus the leachate of the control. Plants irrigated with Tween 20 from 25 to 125 mg·L−1 (0.003338 to 0.01669 oz per gallon) at the 40% or 60% irrigation level had the same height and growth index as plants in the control after three months of growth. Plant fresh and dry weights were not different between the control and the treatments of Tween 20 from 50 to 125 mg·L−1 (0.00668 to 0.01669 oz per gallon) at the 60% irrigation level or the treatment of Tween 20 at 100 mg·L−1 (0.01335 oz per gallon) at the 40% irrigation level. Tween 20 had no effect on net photosynthetic rate. Tween 20 decreased the amount of transpired water of New Guinea impatiens 'Celebrate Salmon'. When the Tween 20 concentration increased from 0 to 100 mg·L−1 (0 to 0.01335 oz per gallon) at the 60% irrigation level, the transpiration rate and stomatal conductance decreased markedly by 43% and 47%, respectively, and water use efficiency was increased by 47%. Results from this study suggest that Tween 20 is able to increase plant water use efficiency through regulation of stomatal conductance or transpiration under deficit irrigation.Index words: irrigation management, chemigation, source-sink physiology, deficit irrigation, wetting agent, Tween 20, adjuvant.Species used in this study: New Guinea Impatiens (Impatiens hawkerii W. Bull. 'Celebrate Salmon').Chemicals used in this study: Tween 20 (polyoxyethylenesorbitan monolaurate). (aka: polysorbate 20, polyoxyethylene (20) sorbitan monolaurate)
Transpiration and Drought Stress Recovery of Three Zinnia Cultivars1
Authors: Roberts Bruce R. , Wolverton Chris 
Published: August 2020

Abstract
Transpiration and drought stress recovery were investigated in three container-grown zinnia cultivars [Zinnia elegans Jacq. (‘Lilliput' and ‘Thumbelina') and Z. haageana Reger (‘Persian Carpet')] by measuring daily changes in the normalized transpiration ratio (NTR) of well-watered (control), water-stressed, and water-stressed/re-watered plants. Transpiration of plants grown in gradually drying substrate did not decline until the fraction of transpirable substrate water (FTSW) reached 0.16 to 0.12. Symptoms of plant-water stress (i.e. foliar wilt) were first observed on the leaves of ‘Persian Carpet', which was also the cultivar with the highest average daily transpiration rate. By comparison, the remaining two cultivars (‘Lilliput' and ‘Thumbelina') exhibited lower average daily transpiration rates and took significantly longer to reach the same dry-down endpoint (NTR ≤0.15). Drought stress recovery was assessed by comparing xylem water potential and root and shoot dry weight in well-watered and in drought-stressed plants following a 7-day stress amelioration period. Xylem water potential of all three drought-stressed cultivars increased (i.e. became less negative) one week after re-watering. Root biomass and root:shoot ratio were both significantly greater in water-stressed plants than in well-watered plants of the same cultivar, a finding that suggests the likelihood of osmotic adjustment in response to drought.
Index words: normalized transpiration ratio, fraction of transpirable substrate water, foliar wilt, containerized horticultural crops.
Species used in this study: ‘Lilliput' and ‘Thumbelina' zinnia (Zinnia elegans Jacq.), ‘Persian Carpet' zinnia (Zinnia haageana Reger).