bluuebunny/crossref_metadata_2025_split huggingface dataset:
Growth Response of Crapemyrtle to Coppicing and Production Light Level
Authors: Brooks K.M. , Keever G.J. , Sibley J.L. , Altland J.E. 
Published: August 2020

Abstract
The effects of production light level on coppicing and coppice timing were evaluated as means of accelerating the development of tree-form crapemyrtles. By the end of the growing season, ‘Fantasy’ and ‘Tuscarora’ coppiced in March and grown under 80% shade were 23 and 18% taller, respectively, than coppiced plants in full sun, but similar in height to plants under 50% shade. Coppiced Dynamite™ under 80% shade and coppiced ‘Carolina Beauty’ under 50% shade were 11 and 26% taller than coppiced plants in full sun, respectively, by the end of the growing season. Height of ‘Fantasy’ and ‘Tuscarora’, but not ‘Natchez’, at the end of the growing season decreased as coppicing was delayed from January to June. ‘Natchez’ coppiced in March were taller than plants coppiced in January or February and 68% taller than plants coppiced in June by the end of the growing season. Cross-sectional stem area of coppiced Dynamite™ and ‘Fantasy’ grown in full sun was greater than that of plants under 50 or 80% shade. Stem area of coppiced ‘Tuscarora’ under 50% shade was greater than that under 80% shade, but similar to that of coppiced plants in full sun. Stem area of coppiced ‘Carolina Beauty’ was greatest when grown in full sun, followed by growth under 50% shade, and least in plants grown under 80% shade. Stem area of ‘Fantasy’, ‘Natchez’, and ‘Tuscarora’ at the end of the growing season decreased linearly as coppicing was delayed from January to June. Visually, coppiced plants had straighter shoots, more uniform shoot diameters, and less branching off the main trunks than non-coppiced plants.
Controlling Height and Seedling Emergence of French Marigold and Celosia Plugs with Plant Growth Regulators
Authors: Magnitskiy Stanislav V. , Pasian Claudio C. , Bennett Mark A. , Metzger James D. 
Published: August 2020

Abstract
Soaking French marigold seeds in growth regulator solutions produced larger reductions in seedling height than foliar sprays. Seeds soaked in 1 to 5 ppm uniconazole solutions for 0.15, 5, or 45 min resulted in plants that were up to 23% shorter than controls at 30 DAS, whereas foliar applications of 10 to 20 ppm uniconazole solutions resulted in plants 18% shorter than controls at 14 DAS. French marigold seedlings from seeds soaked in 60 pm ancymidol for 5 or 45 min were 5 or 6%, respectively, shorter than controls. Foliar spray applications of 25 or 100 ppm ancymidol to French marigold seedlings resulted in plants 8% shorter than controls. Chlormequat solutions applied either as a seed soak (1000–5000 ppm) or foliar spray (500–3000 ppm) did not reduce French marigold seedling height. Emergence of French marigold seedlings from seeds soaked in uniconazole, ancymidol, or chlormequat solutions was not different from that of control seeds. No effect on seedling height or emergence was found when soaking celosia seeds in uniconazole, ancymidol, or chlormequat solutions. Spraying celosia seedlings with uniconazole, ancymidol, or chlormequat solutions did not reduce seedling height.
Ground Pine Chips as a Substrate for Container-grown Woody Nursery Crops
Authors: Wright Robert D. , Browder Jake F. , Jackson Brian E. 
Published: August 2020

Abstract
The objective was to compare pine wood chips (PC) to pine bark (PB) for use as a container substrate for the production of a wide range of woody species. The PC substrate was prepared by grinding coarsely ground [approximately 2.5 cm × 2.4 cm × 0.6 cm (1 in × 1 in × ¼ in)] debarked pine logs (Pinus taeda L.) in a hammer mill to pass a 6.35 mm (0.25 in) screen. Plants of several woody taxa were potted on two different dates (April 4 and May 18, 2005) in each of the two substrates in 3.8 liter (1 gal) containers and grown in a glass house or on outdoor beds in Blacksburg, VA, until late August. Shoot dry weight (SDW) of 13 of 18 species in the April planting was not different between PB and PC, with SDW of four species in this planting being higher when grown in PB and one being higher when grown in PC. Shoot dry weight for 6 of 10 species in the May planting was higher in PB compared to PC. Instances of reduced growth with PC compared to PB were attributed to reduced nutrient availability in PC compared to PB. Results suggest that with adjustments to fertility, PC can be a suitable substrate for container production of woody ornamental plants.
Evaluating a Line Source Irrigation System for Determining Water Requirements of Herbaceous Perennials
Authors: Kjelgren Roger , Cerny-Koenig Teresa 
Published: August 2020

Abstract
We investigated wind effects on the water distribution pattern of a line source irrigation system experimental design that creates a decreasing linear moisture gradient and the growth of twelve perennial wildflower species. Species were randomly assigned to rows perpendicular to a main line of spray irrigation heads, parallel to the decreasing irrigation rates, and irrigated at 110% of evapotranspiration at the heads. At low wind speed (0.44 m/s, 1.4 ft/s), application rates decreased linearly from 50 mm/hr (2 in/hr) for positions closest to the irrigation line to zero at 4 m (12 ft) from the irrigation line. Application rates at positions farthest from the irrigation line were affected by wind speeds as low as 1 m/s (3.3 ft/s). At high wind speeds (3.8 m/s, 12.5 ft/s), application rates at all positions averaged the same across all positions but with extremely high variability. We detected a water stress response in several species known to be drought sensitive. A line source irrigation design offers a potential way to efficiently assess the response of a large number of perennial species to varying irrigation rates by creating a linear moisture gradient, but only when applied under low wind speeds.
Effectiveness of Copper Sulfate Pentahydrate, Mancozeb, and Hydrogen Dioxide in Controlling Anthracnose on Wintercreeper Euonymus
Authors: Boyer Cheryl R. , Cole Janet C. , Conway Kenneth E. 
Published: August 2020

Abstract
Plants of three cultivars of wintercreeper euonymus (Euonymus fortunei (Turcz.) Hand.-Mazz. ‘Emerald Gaiety’, ‘Emerald ‘n Gold’ and ‘Canadale Gold’) were sprayed to runoff weekly with one of three fungicide treatments in 2003 or one of four fungicide treatments in 2004 or water (control) to determine fungicide effectiveness in controlling anthracnose caused by Colletotrichum gloeosporioides (Penz.) Penz. & Sacc. Copper sulfate pentahydrate was applied at 0.4 or 0.6 g ai/liter (0.05 or 0.08 oz/gal) or mancozeb was applied at 1.8 g ai/liter (0.2 oz/gal) in 2003 and 2004 while hydrogen dioxide was applied at 1.1 mL ai/liter (0.1 fl oz/gal) in 2004. Plants were rated for disease symptoms monthly. Cultivars differed at every rating date at both sites in both years with ‘Emerald ‘n Gold’ typically having the highest (worst) disease ratings. ‘Canadale Gold’ usually had the lowest (best) disease ratings while ‘Emerald Gaiety’ was intermediate in disease ratings. No differences in disease rating occurred among fungicide treatments in 2003, but plants treated with mancozeb had the lowest disease ratings in 2004. Inhibition of mycelial growth of two isolates of C. gloeosporioides from wintercreeper euonymus by mancozeb or copper sulfate pentahydrate was tested in vitro at 0, 1, 3.2, 10, 31.6, 100, 316, and 1000 ppm ai. Mycelial growth inhibition of both isolates increased curvilinearly as mancozeb or copper sulfate pentahydrate log10 concentration increased. Copper sulfate pentahydrate caused less than 50% inhibition of mycelial growth at all rates tested. The effective concentration to provide 50% inhibition (EC50) of mancozeb on isolate 415 was 645.7 ppm and on isolate 423 was 602.6 ppm.
Management of Poplar Twiggall Fly on Nursery-grown Aspen
Authors: Cranshaw Whitney , Camper Matthew 
Published: August 2020

Abstract
The poplar twiggall fly (PTGF), Hexomyza schineri (Giraud) (Diptera: Agromyzidae), makes smoothly rounded galls on current season twigs of aspen that persist and continue to expand into large swellings years after insect emergence. Early season observations noted that adults make feeding puncture wounds in foliage with their ovipositor that are good indicators of early season activity. Oviposition in twigs results in an observable swelling of tissues within days. However, full development of galls does not occur until approximately two months following oviposition. Adults typically were active for a period of about two to three weeks subsequent to bud break and its primary parasitoid, the eurytomid Eurytoma contractura Bugbee, was trapped at the end of the PTGF flight period. Efforts to prevent adult emergence by painting galls two weeks prior to adult emergence with either sealants (shellac, polyurethane) or insecticides (imidacloprid, abamectin) did not reduce adult emergence. Soil drench treatments of imidacloprid prior to and immediately following bud break significantly reduced PTGF gall production. High rates of thiamethoxam also provided suppression of galling. Foliar applications tested were ineffective in control of gall production by this insect.
Effects of Kaolin Particle Film on the Viburnum Leaf Beetle During Container Production of Viburnum dentatum under Different Levels of Nitrogen Fertilization
Authors: Schultz Hillary S. , Manley Reeser , Halteman William , Susan Erich M. , Schwintzer Christa R. , Stubbs Constance 
Published: August 2020

Abstract
We investigated two pest management strategies for Pyrrhalta viburni (Paykull), a non-native leaf beetle that has invaded New England and is defoliating susceptible wild and cultivated species of Viburnum. SurroundWP (kaolin wettable powder) was tested as a barrier spray during container production of V. dentatum, to determine if it would affect P. viburni leaf damage, oviposition and plant growth. The effect of added N (nitrogen) was also tested. SurroundWP significantly lowered leaf damage and numbers of egg masses in amended plants, without a negative effect on plant growth. Nitrogen use significantly increased leaf damage by adults, numbers of egg masses, and plant growth. These results suggest that commercial growers of susceptible Viburnum species in areas where P. viburni is found could benefit from the use of SurroundWP, and that N amendment should be kept to a minimum.
Residual Toxicity of Imidacloprid to Hawthorn Lace Bug, Corythuca cydoniae, Feeding on Cotoneasters in Landscapes and Containers
Authors: Szczepaniec Adrianna , Raupp Michael J. 
Published: August 2020

Abstract
Cotoneasters are important and valuable landscape plants. They are severely attacked by hawthorn lace bug (Corythuca cydoniae) in landscapes and nurseries. Imidacloprid has a wide range of activity against many kinds of insect pests. We were interested in determining if cotoneasters treated with soil applications of imidacloprid in landscapes and containers remained toxic to hawthorn lace bugs for more than one growing season. Cotoneasters planted in landscapes were less damaged by lace bugs in the year that imidacloprid was applied and in the following year. We suspect that residual toxicity of leaves of cotoneasters particularly to the nymphs of lace bugs as the cause. Cotoneasters grown in containers demonstrated toxicity to lace bugs for almost 800 days after the application of imidacloprid to the soil. These data greatly extend the known period of efficacy for imidacloprid in controlling hawthorn lace bug on cotoneasters. Clearly, lace bugs are controlled for a minimum of two years. By reducing the need for repetitive applications, a single application of imidacloprid can reduce time, labor and material costs associated with managing this important pest of cotoneasters.
Nodulation and Nitrogen-fixing Capacity of Rhizobial Isolates from China in Symbiosis with Maackia amurensis
Authors: Schrader James A. , Kroggel Mark , Graves William R. 
Published: August 2020

Abstract
Maackia amurensis Rupr. & Maxim (Amur maackia) is a leguminous Asian tree capable of forming N2-fixing symbioses with soil-borne Bradyrhizobium spp. This trait sets Amur maackia apart from many legumes now produced in North American nurseries. Two determinants of N2-fixing capacity in legumes are the compatibility of the host plant and its bacterial microsymbiont and the metabolic efficiency of compatible bacteria. Our objectives were to isolate numerous rhizobia from the root zones of indigenous Amur maackia in China and to select isolates that form superior N2-fixing relationships with inoculated seedlings. Soil samples collected in the Heilongjiang Province of China were used as inocula to establish nodules on seedlings. Putative rhizobia were isolated from these nodules and cultured. Inoculation of additional seedlings with 170 of these isolates evoked nodulation, confirming their identity as rhizobia. Isolates that induced the most nodules were evaluated further. All selected isolates increased growth and total N content of Amur maackia compared to uninoculated controls. Three of the isolates induced more root nodules, and four evoked a higher total N content in plants than did isolate USDA 4349, a previously characterized strain of Bradyrhizobium selected for Amur maackia. Our results demonstrate marked variation among rhizobia compatible with Amur maackia and illustrate the potential to inoculate plants in nurseries and landscapes with superior bacteria, a practice that could reduce fertilizer use and improve performance of trees in N-deficient soils.
Seed Germination of Seabeach Amaranth (Amaranthus pumilus) in Response to Temperature, Light, and Gibberellin A3 Treatments
Authors: Norden Daniel S. , Blazich Frank A. , Warren Stuart L. , Nash David L. 
Published: August 2020

Abstract
Seeds of seabeach amaranth (Amaranthus pumilus Raf.) stored at 4C (39F) for approximately 1 year (harvested September 2003) and freshly harvested seeds (October 2004) were soaked in November 2004 in solutions of the potassium (K) salt (K-salt) of gibberellin A3 (K-GA3) at 0, 100, 500, or 1000 mg/liter (ppm) for 24 hr in darkness. After treatment, seeds were germinated at 25C (77F) or at 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. Stored and fresh seeds responded similarly. However, the 2003 seeds had greater viability (percent germination) and vigor (germinated faster) and these data are presented. Regardless of germination temperature and photoperiod, nontreated seeds [0 mg/liter (ppm) K-GA3] did not germinate. When germinated at 25C (77F) the response of seeds to K-GA3 treatment was linear for both photoperiods with significantly greater total (30-day) germination occurring in the dark for seeds treated with 100, 500, or 1000 mg/liter (ppm) K-GA3. At 25C (77F), the greatest total germination (84%) was observed for seeds treated with 1000 mg/liter (ppm) K-GA3 and maintained in darkness, whereas for seeds exposed to a 16-hr photoperiod, maximum germination was 72%. At 30/20C (86/68F) the response to K-GA3 was quadratic with maximum germination at predicted rates of 882 and 875 mg/liter (ppm) KGA3 (88 and 92%, respectively) for photoperiods of 0 and 16 hr, respectively. Treatment of nonstratified seeds of seabeach amaranth with K-GA3 removed physiological (embryo) dormancy and eliminates the need for stratification (moist-prechilling). Treatment also reduced sensitivity of the seeds to light, and appeared to broaden the range of temperatures for germination.
Single Cyclanilide Applications Promote Branching of Woody Ornamentals
Authors: Holland A.S. , Keever G.J. , Kessler J.R. , Dane F. 
Published: August 2020

Abstract
Single applications of 0 to 200 ppm cyclanilide (CYC), an experimental bioregulator effective in stimulating lateral branching in fruit trees, were applied to the foliage of 19 species or cultivars of woody landscape shrubs over the 2004 and 2005 seasons, 12 of which exhibited increased branching in response to treatment. New shoot increases were concentration and species dependent. Compared to untreated controls at 30 days after treatment (DAT) in 2004, new shoots increased from 14 to 317% across Florida anise, ‘Elizabeth Ann’ Japanese camellia, ‘Nigra’ inkberry holly, ‘Chinsan’ azalea, ‘Red Slippers’ azalea, ‘Watchet’ azalea, ‘Ellen Huff’ oakleaf hydrangea, ‘Brandy's Temper’ sasanqua camellia, and Eleanor Taber™ Indian hawthorn following CYC application. In 2005, shoot increases at 60 DAT ranged from 32 to 240% across ‘Ellen Huff’ oakleaf hydrangea, ‘Brandy's Temper’ sasanqua camellia, Eleanor Taber™ Indian hawthorn, Olivia™ Indian hawthorn, ‘Sky Pencil’ holly, and ‘Foster’ holly. Plant size decreased, increased, or was unaffected by increasing CYC concentration. Foliage of ‘Ellen Huff’ oakleaf hydrangea in 2004 and Eleanor Taber™ and Olivia™ Indian hawthorn in 2005 was injured by CYC application, however symptoms were no longer evident by the end of the growing season. Quality of treated responsive plants at the end of the growing season in 2004, but not in 2005, was usually higher than that of untreated plants and generally increased with increasing CYC concentration.
Nodulation and Growth of Alnus nitida and Alnus maritima Inoculated with Species-specific and Nonspecific Frankia
Authors: Schrader James A. , Graves William R. 
Published: August 2020

Abstract
Actinorhizal plants form N2-fixing symbioses with soil-borne bacteria of the genus Frankia. Potential exists for development of sustainable, actinorhizal nursery crops that obtain most of their required N through N2 fixation, but information on host-symbiont specificity, presence of compatible Frankia in soils, and techniques to inoculate during plant production is lacking. Our objectives were to determine the effect of inoculum type and source and the effect of supplemental N on nodulation, growth, and N content of two actinorhizal species, Alnus nitida (Spach) Endl. and Alnus maritima (Marsh.) Muhl. ex Nutt. Plants of both species were subjected to one of four inoculum treatments (two crushed-nodule inocula: species-specific and cross inoculation, and two soil inocula: soil collected beneath native Alnus rubra Bong. in Washington state and native prairie soil from Iowa), were supplied fertilizer with or without N, and were grown in a greenhouse for 22 weeks. Inoculated plants nodulated, grew larger and faster, and accrued greater N content than uninoculated controls in both fertilizer treatments. Plants that received species-specific inoculum grew larger, acquired more dry weight from symbioses, and accumulated higher N content than cross-inoculated plants. Plants of A. nitida inoculated with soil from Washington state grew larger and accumulated more dry weight from symbioses than those inoculated with prairie soil, but A. maritima grew similarly with soil inoculum from both sources. Our results demonstrate that A. nitida and A. maritima can benefit from N2-fixing symbiosis during production and that potential exists for development of superior inocula and inoculation techniques.
Soil pH and Fertility Affect Growth of Leyland Cypress Christmas Trees
Authors: Hinesley L. Eric , Hardy David , Cleveland Brenda , Myers Jeana 
Published: August 2020

Abstract
Containerized liners of Leyland cypress [Callitropis × leylandii (syn. Cupressus leylandii, × Cupressocyparis leylandii)] were treated with two fertilizer rates [0.6 and 2.4 kg/m3 (1 lb/yd and 4 lb/yd3) of 15N–4.0P–10.0K (15N–9P2O5–12K2O) Osmocote] in Norfolk loamy sand topsoil amended with three rates of dolomitic limestone to obtain target pH values of 4.1, 5.1, and 6.1. Soil pH and fertility both affected plant growth, with negligible interaction. Averaged over both fertilizer rates, total dry weight, which increased linearly with pH, was 24 to 30% higher at the highest pH level (pH 5.9 to 6.5) than in the lowest (pH 4.7 to 4.8). After one growing season, differences among the treatment extremes (low fertility, low pH vs. high fertility, high pH) for height, shoot dry weight, root dry weight, and total dry weight were 19, 71, 44, and 64% respectively.
Drip Chemigation with Imidacloprid and Nematodes for Control of Scarab Larvae in Nursery Crops
Authors: Reding Michael E. , Zhu Heping , Derksen Richard 
Published: August 2020

Abstract
Larvae of scarabs, also known as white grubs, are subterranean insects that damage ornamental nursery crops when they feed on roots. Management is generally based on application of chemical insecticides to the soil surface, followed by supplemental water to leach the toxicants into the soil. Drip irrigation systems have the potential to deliver insecticides and insect pathogens to the root zones of crops to control subterranean insects. From 2004 through 2006, we tested the efficacy of imidacloprid (2004–2006), clothianidin (2006), or entomopathogenic nematodes (EPN) + imidacloprid (2005) applied through drip irrigation to control white grubs in an ornamental nursery. Insecticides (imidacloprid or clothianidin) or EPN + imidacloprid were injected into drip irrigation lines at the upstream end of rows in a commercial nursery. EPN + imidacloprid was also injected into the root zone of trees or applied as a surface drench. In 2004 and 2005, imidacloprid applied at a preventive timing through drip irrigation lines significantly reduced the numbers of white grubs in the root zones of Kousa dogwood (Cornus kousa Hance) trees. In 2006, variation in the data resulted in no significant differences at the P = 0.05 level, although, the percentage reductions of grubs by imidacloprid and clothianidin applied through drip irrigation were similar to trials in 2004 and 2005. EPN + imidacloprid applied through drip irrigation, injected into the soil, and surface drenched at a curative timing all significantly reduced the numbers of grubs compared to untreated trees. These data indicate drip irrigation is a viable delivery system for controls of white grubs in nursery crops.
Root and Shoot Growth Response of Balled-and-Burlapped and Pot-in-Pot Sugar Maple to Transplanting at Five Phenological Growth Stages
Authors: Richardson-Calfee Lisa E. , Harris J. Roger , Fanelli Jody K. 
Published: August 2020

Abstract
The combined effects of phenological growth stage of a tree (e.g., bud break or bud set) and production method on plant response to transplanting are not well documented. This experiment therefore examined shoot extension, trunk diameter increase, and new root length production in balled-and-burlapped (B&B) and pot-in-pot (PIP) sugar maples (Acer saccharum Marsh.) transplanted at five different phenological stages between fall 2000 and early summer 2001 (leaf drop, root quiescence, root activation, bud break, or bud set). Growth measurements were made at bud set and root quiescence in 2001 at bud set in 2002. For B&B trees, total new root length on rhizotron windows was generally greatest for trees planted at bud break and lowest for trees planted at leaf drop. Trees transplanted at leaf drop or root quiescence had the greatest trunk diameter increase, and there was no strong effect of phenological stage at planting on shoot extension. For PIP trees, evidence was weak for a phenological stage effect on post-transplant root length production and trunk diameter increase. Trees transplanted at leaf drop or bud break had the greatest shoot extension. Overall, under the well-irrigated conditions of this study, planting at bud break resulted in the most favorable transplant response for B&B trees, and PIP trees appeared to transplant with equal success at all phenological stages, including after bud set in July.