bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of Soil Compaction and Flooding on the Growth of 12 Willow (Salix L.) Species
Authors: Kuzovkina Yulia A. , Knee Michael , Quigley Martin F. 
Published: August 2020

Abstract
Responses to soil compaction and flooding by 12 Salix species were studied in small mesocosms in a greenhouse over a period of 8 weeks. Two independent experiments were conducted: response of rooted cuttings to soil compaction and response of the same species to three weeks of flooding. Soil atmosphere was analyzed in all treatments. Regardless of level of compaction, oxygen levels were stable and close to atmospheric proportions. However, concentration of carbon dioxide gradually increased in compacted treatments and was the highest in the most compacted soil. Concentration of ethylene remained more or less stable in the compaction treatments. In the flooding treatments a significant decrease of oxygen concentration (9.1%), and significant increases of carbon dioxide (2.15%) and ethylene (1.57μl/liter) took place. All species except S. amygdaloides produced equal or higher biomass in compacted soil compared to a control. Flooding had little effect on the growth of above or below ground parts for most species. Anaerobic conditions triggered a wide range of morphological adaptations: lenticel hypertrophy, formation of adventitious roots (including roots with enhanced aerenchyma), roots growing along the water surface, and roots exhibiting negative gravitropism. Our principal finding was that neither soil compaction nor flooding caused significant reduction in growth of willows.
Height Control of Picea spp. and Chamaecyparis lawsoniana with Uniconazole and 6-Benzyladenine
Authors: Duck M.W. , Cregg B.M. , Fernandez R.T. , Heins R.D. , Cardoso F.F. 
Published: August 2020

Abstract
The use of plant growth retardants (PGRs) could benefit conifer growers by enabling them to produce more uniform, live tabletop Christmas tree specimens. We applied two PGRs to determine effectiveness on height control and terminal bud density for the following species of conifer seedlings: Black Hills spruce (Picea glauca var. densata), Serbian spruce (P. omorika), Colorado blue spruce (P. pungens), and Port Orford cedar (Chamaecyparis lawsoniana). The chemicals were applied at 2-week intervals throughout an 8-week period for a total of four applications. Uniconazole was applied as a foliar spray and soil drench (5 and 1 ppm, respectively), 6-benzyladenine (BA) was applied as a foliar spray (500 and 1000 ppm), and the control did not receive a PGR application. Uniconazole was generally effective on the spruces but not on Port Orford cedar, whereas BA reduced height of all species and increased spruce bud densities. However, BA treatments were phytotoxic in all species tested. The drench of uniconazole caused minor phytotoxicity in Black Hills spruce, whereas foliar applications to Port Orford cedar had minor phytotoxic effects.
Evaluation of Twelve Genotypes of Hibiscus for Resistance to Hibiscus Sawfly, Atomacera decepta Rohwer (Hymenoptera: Argidae)
Authors: Boyd David W. , Cheatham Christopher L. 
Published: August 2020

Abstract
Twelve genotypes of hibiscus were evaluated for resistance to hibiscus sawfly, a minor pest of hibiscus. Evaluations were conducted by counting eggs deposited on the hibiscus and larvae feeding on the hibiscus. Plants were evaluated at the end of the study with a damage rating. Three genotypes demonstrated resistance or tolerance to sawfly feeding: Hibiscus acetosella, H. aculeatus, and H. grandiflora. All three of these genotypes had few, if any, eggs or larvae and were given the lowest damage rating among the genotypes evaluated.
Growing Pinus nigra Seedlings in Spinout™-Treated Containers Reduces Root Malformation and Increases Growth After Transplanting
Authors: Zahreddine Hala G. , Struve Daniel K. , Quigley Martin 
Published: August 2020

Abstract
Root malformation originating during container production causes mechanical instability and plant mortality when those seedlings are transplanted. We investigated the effects of chemical (interior container surfaces treated with Spinout™ or not) or mechanical container modifications (vertical slits or no vertical slits), and the effects of substrate bulk density on the growth of Pinus nigra (Arnold) seedlings during plug production and after transplanting. Seedlings grown in compacted substrate had the greatest shoot, root and total plant dry weights five months after seeding in plug trays. However the incidence of root malformation was also greatest when seedlings were grown in compacted substrate. Unless root pruned, root malformations were retained after transplanting. Seedlings with unpruned roots grown in Spinout™-treated containers had higher regenerated root dry weight than those grown in untreated containers four months after transplanting. Root pruning before transplanting reduced growth of the seedlings regardless of container configuration and of substrate bulk density. Root regrowth and seedling quality after transplanting were greatest for seedlings grown in the treatment combination of no Spinout™, compacted substrate and no slits. Seedlings produced under natural photoperiods formed a resting bud when the seedlings were approximately 2.5 cm (1 in) tall in spring season. Within two weeks shoot elongation resumed, which resulted in branched seedlings. Root malformation can be induced during plug production and is retained after transplanting unless corrected by root pruning.
Provenance and Production Location Affects Growth and Quality of Quercus phellos and Q. shumardii Seedlings
Authors: Pounders Cecil , Fare Donna C. , Cheatham Christopher 
Published: August 2020

Abstract
Seed origin is an important part of oak production that is often ignored by many shade tree growers when selecting material for production. Results of this study indicate interactions between seed sources and production environments have a marked effect on growth and quality of seedlings of willow (Quercus phellos L.) and shumard (Q. shumardii Buckl.) oak in the first two years of production. Seedlings from selected provenances, grown in different hardiness zones, varied more in plant height than trunk caliper and quality. Seedlings from the southern part of the native range of the two species generally grew better in both climates the first growing season. After the second season, total height growth for the various provenances indicated provenance genotype was more important than where seeds were collected. Provenances from the southern native range did not out perform those collected from the central and northern sectors. Exposing seedlings from various provenances to four environmental regiments at two production locations (MS-TN, TN-MS, MS-MS, and TN-TN; referring to year1-year 2, respectively) was more effective at detecting seedlings from provenances with broad environmental adaptation than simply comparing growth at the two locations.
A Comparison of Subcanopy Versus Overhead Application of Constructed Wetland Treated Nursery Runoff on Short and Long Rotation Nursery Crops
Authors: Arnold Michael A. , Lesikar Bruce J. , McDonald Garry V. , Wilkerson Don C. 
Published: August 2020

Abstract
The nursery/greenhouse industry is the fastest growing segment of U.S. agriculture. Consumer demand for excellent product quality requires luxury applications of water and agricultural chemicals. These cultural practices tend to yield significant volumes of runoff rich in nutrients and pesticides. A capture and recycle system at the Nursery/Floral Crops Research and Education Center at Texas A&M University was fitted with 12 gravel filtration sub-surface flow (SSF) and 12 bog-like free-surface flow (FSF) wetland cells. Three cells of each type were planted with Canna x generalis Bailey ‘Cherry Red’, Iris L. x ‘Clyde Redmond’, both species, or no wetland plants. Runoff was continually collected from the nursery and recycled through wetland cells prior to application via overhead impact sprinklers or subcanopy microsprinklers. Short-term (10 wk) differential effects between overhead and subcanopy irrigation during production of Fraxinus pennsylvanica, Pistacia chinensis von Bunge, Quercus virginiana P. Miller, and Taxodium distichum (L.) Richard in 9.4 liter (#3) containers or Ilex vomitoria W. Aiton ‘Nana’ and Catharanthus roseus G. Don in 5.8 liter (#2) containers were limited in magnitude. However, overhead irrigation reduced height and caliper growth or injured the foliage compared to plants irrigated with subcanopy microsprinklers during longer-term (14 months) production in large 87.9 liter (#27) containers. The extent of reduction was species dependent with Pinus elliottii Englemann being minimally impacted, Pyrus calleryana Descaisne ‘Bradford’ intermediate, and Lagerstroemia L. x ‘Basham's Party Pink’ (purportedly a Lagerstroemia indica L. x Lagerstroemia fauriei B. Koehne hybrid) and T. distichum exhibiting more pronounced effects. Damage appeared to be largely a result of high dissolved salt concentrations in irrigation water contacting the foliage. Recycling of runoff through the FSF cells concentrated soluble salts more so than passing the water through the SSF cells. Efficacy of nitrate nitrogen removal varied with species, season, loading rate, and wetland type. However, the constructed wetlands were generally effective under our test conditions at maintaining effluent nitrate levels at ≤10 mg/liter (10 ppm) when loading rates were ≤50 mg/liter (50 ppm). Presence of emergent wetland plants (those with roots imbedded in the substrate and shoots extending above the water surface, rather than floating or submerged plants) in the system was more important for effectively reducing nitrate levels in effluent from SSF than from FSF cells.
Plant Regeneration of Chokecherry (Prunus virginiana L.) from in vitro Leaf Tissues
Authors: Dai Wenhao , Jacques Victoria , Walla James A. , Cheng Zong-Ming 
Published: August 2020

Abstract
An effective plant regeneration system was developed for chokecherry (Prunus virginiana L.) by using in vitro leaf tissues. Adventitious shoots regenerated from in vitro leaf tissues only when cultured on Woody Plant Medium (WPM), but not on Murashige and Skoog medium, supplemented with benzyladenine (BA) or thidiazuron (TDZ). Three chokecherry clones (NN, 10, and 17) responded differently to types and concentrations of cytokinins, ranging from 16.7 to 91.7% leaf explants regenerating shoots. A mean of four shoots was produced from each explant, with the most shoots (&gt; 10) from clone NN on media with 5–10 μM BA. Higher concentrations of TDZ (&gt; 8 μM) caused serious vitrification and eventual death of newly induced shoots. Regenerated shoots (&gt; 1.5 cm) produced roots in vitro in half strength MS medium or ex vitro in Cellular Rooting Sponge (CRS) rooting plugs with or without auxin (NAA or IBA) treatments. Rooting was affected by auxin, genotypes, and the rooting methods.
Effect of Nickel Applications for the Control of Mouse Ear Disorder on River Birch
Authors: Ruter John M. 
Published: August 2020

Abstract
Mouse ear (leaf curl, little leaf, squirrel ear) disorder has been a problem in container-grown river birch (Betula nigra L.) for several decades. The disorder is easy to detect in nurseries as the plants appear stunted due to shortened internodes which give the appearance of a witches-broom. The leaves are small, wrinkled, are often darker green in color, are commonly cupped and have necrotic margins. Plants grown in soil rarely express the disorder. A trial was initiated in June 2003 to determine if a deficiency of nickel was the cause of mouse-ear on river birch. Symptomatic river birch trees (Betula nigra ‘BNMTF’ Dura-Heat™) in their second growing season in #15 containers were selected for uniformity of size and mouse ear. Treatments included a 1) control, 2) 789 ppm Ni sprays, 3) 394 ppm Ni sprays, 4) 0.005 lbs Ni/yd3 as a drench, 5) 26 g/pot triple superphosphate (0–46–0), and 6) 130 g/pot Milorganite. Nickel was applied as nickel sulfate, whereas triple superphosphate and Milorganite contain trace amounts of nickel. At 16 days after treatment, up to 5 cm of new growth was evident on plants sprayed with nickel. Thirty days after treatment shoot length increased up to 60%, leaf area increased 80 to 83%, and leaf dry mass increased 76 to 81% for plants sprayed or drenched with nickel sulfate. Plants treated with triple superphosphate or Milorganite did not resume normal growth. All plants treated with nickel sulfate in 2003 did not show symptoms of mouse ear after initiation of growth in 2004. Based on this research mouse ear disorder of river birch is caused by a deficiency of nickel which can be corrected by foliar or drench applications of nickel sulfate.
Seed Germination of Seabeach Amaranth (Amaranthus pumilus) as Influenced by Stratification, Temperature, and Light
Authors: Blazich Frank A. , Warren Stuart L. , Nash David L. , Reece William M. 
Published: August 2020

Abstract
Freshly harvested seeds of seabeach amaranth (Amaranthus pumilus Raf.) were stratified (moist-prechilled) for 0, 30, 60, 90, or 120 days. Following stratification, seeds were germinated at 25C (77F) or an 8/16 hr thermoperiod of 30/20C (86/68F) with daily photoperiods at each temperature of 0 (total darkness) or 16 hr. Germination was recorded every 3 days for 30 days. Regardless of photoperiod or duration of stratification, germination at 25C (77F) was negligible. After 120 days of stratification, total (30-day) germination at 25C (77F) with photoperiods of 0 or 16 hr was 4 and 3%, respectively, whereas considerable germination occurred at 30/20C (86/68F). Germination increased linearily with increasing durations of stratification for both photoperiods when seeds were germinated at 30/20F (86/68F). In addition, germination increased when seeds were exposed to light. After stratification of 30 days and germination in the dark at 30/20C (86/68F), germination of 20% was observed by day 12 and increased to 27% by day 30, whereas for seeds exposed to a 16-hr photoperiod, 16% germination was noted by day 12 increasing to 38% by day 30. Following stratification of 120 days and germination in the dark at 30/20C (86/68F), germination of 49% was observed by day 12 increasing to 50% by day 30, whereas for seeds exposed to light, 82% germination was realized by day 12 increasing to 85% by day 30.
BA Application Frequency and Concentration Effects on Two Indian Hawthorn Cultivars
Authors: Oates Jayme M. , Keever Gary J. , Kessler J. Raymond 
Published: August 2020

Abstract
Benzyladenine (BA) is a synthetic cytokinin that promotes lateral shoot development in herbaceous and woody ornamentals and may be a viable alternative to mechanical pruning in nursery production. A study was conducted to determine the effects of BA application number, interval and concentration on two Indian hawthorn [Rhaphiolepis Lindl. Cor. Poir. indica (L.) Lindl. (Crataegus indica L.)] cultivars. In spring 2002, actively growing ‘Olivia’ and ‘Eleanor Taber’ received three applications of 2500 or 5000 ppm BA at a one-, two-, or three-week interval. Data collected four weeks after initial treatment (WAT) reflected the effects of one, two, or three BA applications at each concentration. At this time new shoot counts in both cultivars and foliar injury in ‘Olivia’, but not in ‘Eleanor Taber’, increased with increasing number of applications and BA concentration. Data collected 12 WAT reflected the effects of BA application interval and concentration. At this time new shoot counts increased with decreasing application interval in ‘Olivia’, while ‘Eleanor Taber’ formed the most new shoots when BA was applied at a two-week interval. All treated plants sustained minimal to moderate injury to immature foliage. The experiment was repeated in 2003 using 1750 ppm and 3500 ppm BA on ‘Olivia’ Indian hawthorn. Applications were halted at the first sign of foliar injury resulting in plants treated at one, two, and three-week intervals receiving three, two, and two applications, respectively. New shoot counts on ‘Olivia’ treated at the three application intervals were similar, but greater than those on untreated plants. Control plants had a foliar injury rating similar to that of plants treated at a two or three-week interval, but less than that of plants treated at a one-week interval. Growth index was not affected by treatment in either year.
DNA Fingerprinting of Clones and Hybrids of American Elm and Other Elm Species with AFLP Markers
Authors: Pooler Margaret R. , Townsend A.M. 
Published: August 2020

Abstract
The elms represent a diverse group of widely distributed temperate trees that are valued for forest products as well as landscape plants. Genetic diversity was examined among 43 Ulmus accessions, including 19 accessions of American elm and representatives of seven other species. Data from 135 markers from five AFLP primer pairs were used to estimate genetic similarity among accessions and to construct a UPGMA-derived dendrogram. While the species clusters were generally well-resolved, the relationships among clones and hybrids of American elm were less distinct. Our data provides some evidence to support the hybrid origin of two previously unverified U. parvifolia × U. americana clones, and provides evidence that the new clone N3487 (‘Jefferson’), an elm whose origin has been questioned, is an American elm.
Efficacy and Costs Associated with the Manual Removal of Bagworms, Thyridopteryx ephemeraeformis, from Leyland Cypress
Authors: Lemke Hans D. , Raupp Michael J. , Shrewsbury Paula M. 
Published: August 2020

Abstract
Bagworms (Thyridopteryx ephemeraeformis) are a common pest of landscape plants. The efficacy and costs were determined for the manual removal (handpicking) of bagworms from a single Leyland cypress (X Cupressocyparis leylandii) and estimated for a planting of 40 trees. Manual removal costs were compared to the estimated costs of spraying trees with the insect growth regulator tebufenozide. Handpicking the bags provided 92% control and required 160 minutes for one tree and an estimated 6,400 minutes for 40 trees. Labor costs for manual removal were estimated at $44 for one tree and $1764 for 40 trees. Estimated time required to spray a single tree was 71 minutes while 40 trees required an estimated 251 minutes. Estimated cost to spray one tree was about $28 and the cost for 40 trees was estimated to be $105. The time spent and costs of control are similar for handpicking and spraying single trees. Handpicking may be acceptable on single or small numbers of short trees that may be safely handpicked. However, as the number of trees increases, time and costs associated with handpicking increase dramatically, while costs to spray increase only slightly.
Landscape Plant Material, Size, and Design Sophistication Increase Perceived Home Value
Authors: Behe B. , Hardy J. , Barton S. , Brooker J. , Fernandez T. , Hall C. , Hicks J. , Hinson R. , Knight P. , McNiel R. , Page T. , Rowe B. , Safley C. , Schutzki R. 
Published: August 2020

Abstract
Little consumer research is available to help landscape design and installation businesses develop service marketing strategies. We investigated the effect of three components of a landscape design on the perceived value of a home. This information would be useful in marketing lawn and landscape services to prospective clients. Our objective was to provide a consumer perspective on the value of the components in a ‘good’ landscape and determine which attributes of a landscape consumers valued most. Using conjoint design, 1323 volunteer participants in seven states viewed 16 photographs that depicted the front of a landscaped residence. Landscapes were constructed using various levels of three attributes: plant material type, design sophistication, and plant size. Results showed that the relative importance increased from plant material type to plant size to design sophistication. Across all seven markets, study participants perceived that home value increased from 5% to 11% for homes with a good landscape.
Sumagic (Uniconazole) Promotes Flower Bud Set on Camellia japonica
Authors: Banko Thomas J. , Landon Amelia L. 
Published: August 2020

Abstract
Three-year-old container-grown plants of Camellia japonica ‘Grace Albritton’, ‘Paulette Goddard’, and ‘Sea Foam’ were sprayed with a water control, B-Nine (daminozide) at 5000 ppm, Bonzi (paclobutrazol) at 80, 120, 160, 200, and 240 ppm, or Sumagic (uniconazole) at 30, 45, 60, 75, and 90 ppm in June. B-Nine and Bonzi treatments provided no increase in flower bud set but Sumagic treatments increased bud set for ‘Grace Albritten’ by up to 370% and ‘Paulette Goddard’ by 200%. In another experiment, Sumagic at 0, 45, 60, 75, and 90 ppm was applied to ‘Grace Albritton’, ‘Paulette Goddard’, and ‘Blood of China’ at three different spring growth stages: Bud swell, partial new shoot growth, and new shoots fully extended. Significant linear or quadratic increases in flower bud set occurred for all cultivars depending on application timing. Application at the two earlier stages resulted in more flowers than application at the latest (full shoot growth) stage. Sumagic decreased plant heights by 10 to 30%, depending on cultivar and application rate but this reduced the need for shearing to maintain form and compactness and made flowers more visible over the surface of the plants.
Effects of K-IBA on the Rooting of Stem Cuttings of 15 Taxa of Snowbells (Styrax spp.)
Authors: Griffin Jason J. , Lasseigne F. Todd 
Published: August 2020

Abstract
Currently, information regarding asexual propagation of Styrax L (snowbells) is lacking in the literature. In this study, the influence of K-IBA treatment on root production was investigated on stem cuttings of 15 different taxa of Styrax. Softwood or semi-hardwood stem cuttings dipped in 0, 3000, or 8000 ppm (0, 0.3, or 0.8%) K-IBA were evaluated for percent rooting and root number per rooted cutting. Cuttings were allowed to root under intermittent mist in a perlite:peat (3:1 by vol) rooting substrate for 9 weeks. Percent rooting and the response to K-IBA varied by species and by cultivar within a species. All 15 taxa rooted to some extent. Auxin application improved percent rooting for S. dasyanthus, S. japonicus ‘Carillon’, S. japonicus ‘Pink Chimes’, S. japonicus ‘Snowfall’, and S. tonkinensis, and decreased percent rooting for S. formosanus, S. japonicus ‘Issai’, S. japonicus ‘Pink Cascade’, and S. serrulatus (clone B). Application of K-IBA increased the number of roots produced per rooted cutting on S. calvescens, S. confusus, S. japonicus ‘Pink Chimes’, S. serrulatus (clone A), and S. tonkinensis.
Evaluation of Herbaceous Perennials as Weed Suppressive Groundcovers for Use Along Roadsides or in Landscapes
Authors: Eom Seok Hyun , Senesac Andrew F. , Tsontakis-Bradley Irene , Weston Leslie A. 
Published: August 2020

Abstract
Fifteen herbaceous perennials were evaluated in field experiments in two New York State locations to determine their utility in roadside and landscape areas as weed suppressive groundcovers. Four species, Alchemilla mollis, Nepeta x faassenii, Phlox subulata, and Solidago sphacelata were strongly weed suppressive in both managed (weeds removed) plots and unmanaged (weeds not removed) plots. Weed suppressivity of perennial groundcovers was significantly increased in year two in both locations when perennials were well established. The most suppressive perennials showed several similar characteristics likely associated with their successful establishment. Successful groundcovers possessed dense foliage which strongly reduced light transmittance at the soil surface and emerged relatively early in spring. Lamiastrum galeobdolon and Thymus praecox proved to be more successful over a 2-year period when managed by weed removal in early spring. Although Leymus arenarius, a relatively tall monocot, also inhibited weed growth, this species demonstrated invasive characteristics due to its spread outside plots by fast-growing rhizomes.