bluuebunny/crossref_metadata_2025 huggingface dataset:
Pruning Method Affects Flowering and Sprouting on Crapemyrtle
Authors: Gilman Edward F. , Knox Gary W. , Gomez-Zlatar Patricia
Published: August 2020

‘Natchez’ (Lagerstroemia indica × fauriei) and ‘Carolina Beauty’ (Lagerstroemia indica L.) crapemyrtle were pruned in three manners including topping, pollarding, and pencil-pruning plus a non-pruned control for four years to determine influence on flowering and sprouting. The topping and pollarding of ‘Natchez’ delayed appearance of the first flower up to one month compared to non-pruned trees for the first two years following initial pruning. In contrast, topping and pollarding ‘Carolina Beauty’ induced flowering by as much as one week sooner one and three years following initial pruning with no effect in years two and four. Topping both cultivars delayed peak flowering date compared to non-pruned trees. Topping ‘Natchez’ the first and second year following initial pruning and pollarding in the second year reduced duration of flowering period compared to the non-pruned trees. Flower effect (panicle number × panicle volume) was not influenced by pruning method on ‘Carolina Beauty’ for any year. Flower effect for topped ‘Natchez’ was significantly smaller than for pollarded and pencil-pruned trees the first year after pruning; flower effect on non-pruned ‘Natchez’ was no different from any of the pruning treatments. Pruning cut diameter was inversely correlated with number of days ‘Natchez’ trees were in flower, number of flower panicles, and date of flowering; however, cut diameter influence on flower effect was not predictable for ‘Carolina Beauty’. Sprouting along the trunk and from the roots increased with diameter of the pruning cut. Topping took less time to complete than other pruning methods in all but the last year which probably accounts for its popularity. Topped trees grew in height following pruning faster than pollarded trees, which grew faster than pencil-pruned trees, which grew faster than non-pruned trees for both cultivars.
Limited Inductive Photoperiod Affects Herbaceous Perennials Grown Under Nursery Conditions in the Southern United States
Authors: Keever Gary J. , Kessler J. Raymond , Stephenson James C.
Published: August 2020

A study was conducted to determine if limited inductive photoperiod (LIP) initiated in late winter could be used to control stem elongation in ‘Goldsturm’ coneflower (Rudbeckia fulgida ‘Goldsturm’), ‘Moonbeam’ coreopsis (Coreopsis verticillata ‘Moonbeam’), or ‘Early Sunrise’ coreopsis (Coreopsis grandiflora ‘Early Sunrise’), grown outdoors under nursery conditions in the southern United States, without negating the benefits of earlier flowering from night-interrupted lighting (NIL). Treatments were NIL beginning on February 1 and ending on February 15, March 1, March 15, or April 1,2002, plus a natural photoperiod (NP) treatment. The experiment was repeated in 2003 with the inclusion of an additional NIL treatment ending on April 15. LIPs of at least 15 to 30 days, 30 to 45 days, and 30 to 45 days promoted earlier flowering of ‘Early Sunrise’ coreopsis, ‘Moonbeam’ coreopsis, and ‘Goldsturm’ coneflower, respectively. Flower counts and quality ratings of the three cultivars that received LIPs were similar to or higher than those of plants under a NP, except for a reduction in flowering and quality ratings of ‘Goldsturm’ coneflower exposed to LIPs ending on March 1 and March 15, 2002, and on March 1, 2003, and later. LIP effects on plant height were mixed, although there was at least one duration of LIP that resulted in earlier flowering of the three cultivars and plants similar to or shorter than plants under a NP.
Online Gardening Search Activities and Purchases
Authors: Behe Bridget K. , Harte Brittany , Yue Chengyan
Published: August 2020

Consumers have readily adopted personal computers and Internet technology with many seeking information and/or make purchases online. However, the extent to which horticultural consumers seek information and make purchases online is not well documented. A survey of 1588 consumers, representative of the United States on average, was conducted in 2004 to provide baseline information about online gardening search and purchase activities. Nearly 28% searched for gardening information at least once; of those, more than 50% of the participants searched for information at least weekly. There were differences in gardening-related searches by age and marital status, but not by region of residence, income, or gender. Nearly 50% of the study respondents made an online purchase in the year prior to the survey but only 7.4% made a gardening related purchase online. Over 50% had made a gardening-related purchase in-person. The same respondents who made in-person purchases were the individuals who made the online gardening purchases, so the Internet provided a supplemental shopping venue. There were demographic differences between those who made online gardening purchases and solely in-person gardening purchases. More males, younger and slightly less affluent participants were more likely to make online purchases than solely in-person purchases for gardening products, supplies, and services while more females who were slightly older and more affluent were more likely to make in-person gardening-related purchases.
Propagation of Selected Clones of Eastern Redbud (Cercis canadensis) by Stem Cuttings
Authors: Wooldridge John M. , Blazich Frank A. , Warren Stuart L.
Published: August 2020

Two experiments, one utilizing softwood cuttings and the other semi-hardwood cuttings, were conducted to investigate the influence of growth stage and auxin treatment on rooting four related clones of eastern redbud (Cercis canadensis L.). The four clones were ‘Flame’ (C. canadensis L. ‘Flame’), dwarf white, and two selections (NC99-6-1 and NC99-6-2) of an F1 generation derived from a cross of ‘Flame’ and dwarf white. At each growth stage, rooting responses of the clones varied and were influenced greatly by auxin treatment, demonstrating the variable rooting potential of the genotypes. In both studies, ‘Flame’ rooted well [63% rooting in the softwood study when treated with the potassium (K) salt (K-salt) of indolebutyric acid (IBA) at 5000 mg·L−1 (ppm), 83% rooting when treated in the semi-hardwood study with K-IBA at 10,000 mg·L−1], indicating stem cuttings may be a commercially feasible means of propagation for ‘Flame.’ Softwood cuttings of dwarf white (46%) and NC99-6-2 (75%) rooted best when treated with K-IBA at 15,000 mg·L−1, whereas softwood cuttings of NC99-6-1 rooted best (46%) when treated with K-IBA at 10,000 mg·L−1. Dwarf white and the F1s rooted poorly in the semi-hardwood study.
Impact of Improved Landscape Quality and Tree Cover on the Price of Single-Family Homes
Authors: Stigarll Andrea , Elam Emmett
Published: August 2020

Impacts of the quality of landscaping and percentage of tree cover on home prices were estimated from a sample of 75 home sales within the Melonie Park neighborhood in Lubbock, TX, from 2003 to 2005. Estimates were derived using a regression of house sale price on house characteristics, landscape quality, and tree cover. Homes that improved landscaping from average quality to good or excellent quality increased selling price by 5.7 and 10.8%, respectively. Approximately 30% of the increase in sale value was accounted for by added tree cover. The results show that each $1.00 invested in upgrading an average landscape to excellent quality returns $1.35 in added property value.
Pruning Roots Affects Tree Quality in Container-Grown Oaks
Authors: Gilman Edward F. , Harchick C. , Wiese C.
Published: August 2020

Height and trunk growth of Quercus virginiana ‘SDLN’ Cathedral Oak® tops was not affected by root pruning that occurred each time trees were potted into a larger container, beginning when rooted cuttings were planted into #3 containers. All trees produced in air root-pruning Accelerator® containers without mechanical root pruning produced enough circling roots to make them culls according to Florida and California standards for nursery stock. Removing root defects by pruning roots when trees are potted to the next larger size reduced culls from 100% to 40% of the crop and is recommended for quality tree production. Root pruning when trees were potted from one container size to the next size had no influence on the number of primary structural roots that grew directly from the trunk base. Root pruning had no impact on the number of roots that were deflected down. Waiting to root prune until #3 containers were potted into #15 containers did not increase the number of straight roots compared to non-pruned controls. Slicing the root ball edges vertically from top to bottom in several places appears to reduce circling roots capable of forming stem girdling roots. But slicing in the manner described in this study did little to reduce the descending root defects.
Anthracnose on Wintercreeper Euonymus is not Reduced with Polyethylene Sheeting or Sodium Hypochlorite
Authors: Cole Janet C. , Boyer Cheryl R. , Payton Mark E. , Conway Kenneth E.
Published: August 2020

Wintercreeper euonymus (Euonymus fortunei (Turcz.) Hand.-Mazz. ‘Emerald ‘n Gold’) plants were grown in containers on gravel beds that were covered or not covered with black polyethylene sheeting. Half of the beds in each bed treatment were sprayed with a 0.6% sodium hypochlorite (10% bleach) solution immediately after rating plants or performing needed cultural practices such as shearing and weeding (about monthly) to attempt to suppress anthracnose caused by Colletotrichum gloeosporioides (Penz.) Penz. & Sacc. Plants were rated for disease severity monthly from May through September at one site in 2005 and at two sites in 2006. Presence or absence of polyethylene sheeting or sodium hypochlorite did not affect disease ratings. Disease ratings increased curvilinearly as the growing season progressed. In vitro tests showed that sodium hypochlorite did not inhibit mycelia growth of C. gloeosporioides but eliminated conidial germination.
Preemergence Herbicide Applications to Six Containerized Woody Ornamental Rootstocks do not Affect Winter Grafting Success
Authors: LeBude Anthony V. , Upchurch Brian L. , Neal Joe
Published: August 2020

Five common preemergence herbicides [Scotts OH2 (oxy fluorfen and pendimethalin), Snapshot TG (trifluralin and isoxaben), Ronstar (oxadiazon), SureGuard (flumioxazin), or BroadStar (flumioxazin)] were each applied at the highest labeled rates at 6 to 8 week intervals over the growing season to six species of container-grown seedling rootstocks. Dormant scions were bench-grafted to their respective rootstocks the following winter. Research was conducted in 2006–2007 and repeated in 2007–2008. Treatment effects were compared to non-treated control plants. Preemergence herbicide treatments had no effect on grafting success for any of the cultivars. Data indicate that these preemergence herbicides, labeled for use in container-grown nursery crops, can be used in accordance with label recommendations to control weeds in containerized rootstocks without affecting subsequent grafting success.
Degradation and Nitrogen Release of Zein-based Bioplastic Containers
Authors: Helgeson Matthew S. , Graves William R. , Grewell David , Srinivasan Gowrishankar
Published: August 2020

Environmental problems caused by petroleum-based plastics have led to interest in alternatives made from biodegradable polymers (bioplastics), but little effort has been made to evaluate horticultural containers made from these materials. We hypothesized the stability and longevity of containers made from polymers of the hydrophobic corn (Zea mays L.) protein, zein, is sufficient to make commercial use of zein-based containers feasible. Our objectives were to fabricate containers from zein, to determine longevity under conditions typical of horticultural production, and to identify limitations of the containers that might be overcome by further research. Zein-based, bioplastic containers of two wall thicknesses were filled with either a peat-based, soilless potting substrate or with coarse perlite and irrigated every 2 or 4 days. After 10 weeks, weight loss of containers was determined as a measure of their degradation. Containers filled previously with soilless substrate lost nearly twice as much weight as containers filled with perlite, and irrigation every 4 days led to greater weight loss than irrigation every 2 days. The containers released nitrogen (N) as they degraded; as much as 208 mg N·kg−1 was present in leachate after irrigation with water. In a second experiment, to simulate the potential practice of installing plants in the landscape without container removal, bioplastic containers of two sidewall thicknesses were filled with the soilless potting substrate and planted in either drained or saturated field soil, and the two substrates were either sterilized (autoclaved) or nonsterilized. After 12 weeks, containers in drained soils had greater weight loss than containers in saturated soils regardless of substrate sterilization treatment. Zein-based, bioplastic containers appear suitable for crops having production cycles of ≤ 3 months, and the containers will decompose and release N if installed with plants in the landscape. Further research is needed to increase the longevity of zein-based containers for crops with longer production cycles. In addition, the influence of containers made from zein on plant growth needs to be determined, and potential effects of degrading containers installed in the landscape on the establishment of transplants warrant investigation.
Implementing and Assessing an Onsite Bilingual Educational Program for Hispanic Nursery Workers in Ohio
Authors: Acuna Alejandra , Mathers Hannah
Published: August 2020

Technical training plays a significant role in job retention, advancement and increased remuneration potential. Bilingual content has been shown to improve Hispanics understanding of the subject matter and English skills. Family income is a major stabilization or destabilization force in families. We hypothesized that by providing a series of three bilingual training sessions to Hispanic nursery workers related to American culture/life skills (LS) and/or horticulture skills (HS) that could potentially lead to job advancement opportunities, we could improve workers' self-esteem, work motivation and family-relations. There were three main objectives to this study: 1) to assess the validity of a Spanish translated version of The Index of Family Relations (IFR) and the Rosenberg Self-Esteem Scale (RSE) to evaluate family adjustment problems and self-esteem, respectively, when administered to 97 adult Hispanic nursery employees in seven Ohio nurseries in 2005 and 2006; 2) to determine if nurseries differed in their training needs; and, 3) to define which type of training LS or HS (without LS) could improve family adjustment and/or self-esteem. Ninety seven (43% female, 57% male) of 150 employees originally contacted (35%), completed all three trainings and both pre-and post-testing, which were requirements for inclusion in the analyses. The 35% attrition rate (26% with males, 8% with females, averaged over 7 nurseries) indicates the difficulties in offering even a free, on-farm training program for Hispanic nursery employees. The results of the Chronbach's alpha for the IFR and RSE were 0.8 and 0.68 before and 0.86 and 0.7 after the training, respectively, indicating that the IFR and RSE (> 0.6 required validity) tests were valid and marginally valid, respectively, for this audience. Differences in RSE (p < 0.0078) and IFR (p < 0.0625) scores were detected using before and after scores across nurseries with non-opposing or identical distributions. The results indicate that self-esteem and to a lesser extent family relations can be improved by providing nursery need specific training and LS training having the greatest effect across nurseries. At one nursery IFR scores above 30 were observed with only LS lowering scores to non-critical. At some sites basic LS trainings seemed critical before successful HS training discharge. This study seems to identify problem employers and could be fundamental in improving employer/worker relationships within the nursery industry.
Effects of Irrigation Volume and Frequency on Shrub Establishment in Florida
Authors: Gilman E.F. , Wiese C.L. , Paz M. , Shober A.L. , Scheiber S.M. , Moore K.A. , Brennan M.
Published: August 2020

Irrigation frequency and volume effects were evaluated on recently installed #3 container grown shrubs of three taxa, Ilex cornuta Lindl. & Paxt. ‘Burfordii Nana’, Pittosporum tobira Thunb. ‘Variegata’, and Viburnum odorotissimum Ker Gawl. Irrigation frequency and volume had no effect on Pittosporum at any time for any measured root or shoot parameter. Irrigation frequency and volume had no effect on Ilex and Viburnum canopy biomass, root biomass, root dry weight:canopy dry weight ratio, and stem water potential at any time after planting. Canopy growth was affected by irrigation treatment only for Viburnum plants installed in May 2004, and growth response to more frequent irrigation only occurred while plants were irrigated, with no lasting impact on growth once irrigation ceased. Root spread and root spread:canopy spread ratio for only one species, Ilex, were influenced by irrigation treatment. Applying excessive irrigation volume (in this case 9L) reduced root dry weight: shoot dry weight ratio for Ilex and could increase the time needed for plants to grow enough roots to survive without irrigation. Our study found only slight influences on shrub growth from the tested values of irrigation frequency and volume regardless of the time of year when data was collected. This indicates that these shrubs can be established with 3 liters irrigation applied every 4 days until roots reach the edge of the canopy under the mostly above normal rainfall conditions of this study. Applying more volume or irrigating more frequently did not increase survival or growth. Canopy growth and plant quality data combined with past research suggest that establishment of these shrub species may be more influenced by environmental conditions such as rainfall than by the irrigation frequency and volume used in this test.
Cutting Back Stock Plants Promotes Adventitious Rooting of Stems of Quercus bicolor and Quercus macrocarpa
Authors: Naalamle Amissah J. , Bassuk Nina
Published: August 2020

Studies were conducted to investigate the severity of cutting back stock plants on adventitious rooting of layered stems and stem cuttings of Quercus bicolor Willd. (swamp white oak) and Quercus macrocarpa Michx. (bur oak). Rooting averaged 77% in Q. bicolor and 70% in Q. macrocarpa layered stems from the cutback stock plant group, compared to air layered stems from intact plants which averaged 1% in Q. bicolor and 0% in Q. macrocarpa. In another experiment cuttings were taken from three stock plant heights [4 cm (1.6 in), or 100 cm (39.4 in) stumps and intact plants ∼ 170 cm (66.9 in)] which were either etiolated or grown in natural light and rooted under mist. The best rooting (59%) and average number of roots (9.3) were found in etiolated Q. bicolor cuttings taken from 4 cm (1.6 in) stumps. Q. macrocarpa cuttings rooted poorly with only 7% of the cuttings rooting. By taking cuttings a week earlier for rooting (2 weeks, at the softwood stage), rooting in Q. macrocarpa was possible, with the best rooting (46%) found in etiolated cuttings taken from 4 cm (1.6 in) stumps. Overall, the highest rooting and greatest number of roots occurred in etiolated layers and cuttings from the 4 cm cutback group. Rooting generally increased with increasing extent of stock plant cutback
Effect of Landscape Mulches and Drip Irrigation on Transplant Establishment and Growth of Three North American Desert Native Plants
Authors: Singer Catherine K. , Martin Chris A.
Published: August 2020

A two-year experiment was conducted to determine growth responses of three North American desert native plants, brittle bush (Encelia farinosa), four wing salt bush (Atriplex canescens), and Santa Rita prickly pear cactus (Opuntia santa rita) to four landscape mulch treatments (shredded landscape tree trimmings, composted ponderosa pine residue, decomposing granite, or a no mulch control). In addition, brittle bush and four wing salt bush plants were drip irrigated with either 1275 liters (337 gal) or 2550 liters (674 gal) of water-plant−1year−1. Santa Rita prickly pear cacti were not irrigated. Transplant survivability of brittle bush was differentially affected by mulch treatment. In contrast, mulch treatments had no impact on survivability of four wing salt bush or Santa Rita prickly pear. Mulch treatments also had no effect on growth indices of all plants. Compared to the no mulch control treatment, shredded tree trimming mulch increased relative water content of Santa Rita prickly pear padded stems. Shoot dry weights were greatest for non-irrigated four wing salt bush and brittle bush. These findings suggest that supplemental drip irrigation and inorganic mulches might not be needed to grow some North American desert plants in southwest urban landscapes.
Vegetative Propagation of Gordonieae Trees by Stem Cuttings
Authors: Meyer Elisabeth M. , LeBude Anthony V. , Ranney Thomas G.
Published: August 2020

The Theaceae tribe Gordonieae contains trees with desirable ornamental characteristics and adaptability to a broad range of environmental conditions. To develop an effective protocol for vegetative propagation of five taxa in the tribe, terminal softwood, semi-hardwood, and hardwood cuttings were collected from these trees and treated with either 0, 2500, 5000, 7500, or 10000 ppm of the potassium salt of indolebutyric acid (K-IBA). The concentration of K-IBA only affected rooting percentage of hardwood cuttings of Franklinia alatamaha, Gordonia lasianthus, and Schima remotiserrata and had varying effects on root number and length of longest root amongst the taxa and cutting types. Franklinia alatamaha and G. lasianthus were rooted at high percentages (> 50%) from hardwood, semihardwood, and softwood cuttings, and S. khasiana rooted at high percentages (72%) from softwood cuttings. Despite poor rooting from all types of stem cuttings (< 23%), Schima remotiserrata and S. wallichii exhibited the highest rooting percentages from hardwood cuttings. Rooting percentage, root number, and length of longest root differed greatly in response to K-IBA concentration amongst the five taxa observed and the cutting types within each taxa.
Exogenous Abscisic Acid Application Effects on Stomatal Closure, Water Use, and Shelf Life of Hydrangea (Hydrangea macrophylla)
Authors: van Iersel Marc W. , Seader Kate , Dove Sue
Published: August 2020

A lack of adequate watering reduces the shelf life of many ornamental plants during retail. Our goals were to determine whether sprays or drenches with abscisic acid (ABA) can reduce transpiration and extend the shelf life of hydrangea (Hydrangea macrophylla). During the first 5 days after treatment, ABA drenches of 125 to 1000 ppm reduced stomatal conductance (gs) by 50 to 80% as compared to water. ABA-induced stomatal closure reduced plant water uptake from the substrate; control plants took up half of the plant-available water during the first 7 days after treatment, while it took 14 days for plants drenched with 1000 ppm to take up half of the available water. Control plants wilted after 12 days and time to wilting of drenched plants increased with increasing ABA concentrations, up to 23 days in the 1000 ppm treatment. Spray treatments had little effect on gs and no detectable effect on water uptake or time to wilting. Some yellowing of older leaves was seen with ABA drenches of 500 or 1000 ppm. Despite this side effect, ABA drenches have potential to extend the shelf life of hydrangeas in retail environments.
Recycled Mushroom Compost Suppresses Bird's Nest Fungi in Landscape Mulch
Authors: Fidanza Michael A. , Davis Donald D.
Published: August 2020

Mushroom compost blended into landscape mulch has been reported to suppress sporulation of artillery fungi (Sphaerobolus spp). In this paper, mushroom compost is also shown to inhibit growth and sporulation of a common bird's nest fungus in landscape mulch. Field plots containing 0, 10, 20, 40, or 100% (by volume) mushroom compost blended with a common landscape mulch were naturally infested with a bird's nest fungus (Cyathus stercoreus (Schweinitz) de Toni). Compost at percentages ≥ 40% significantly reduced growth and sporulation of the bird's nest fungus. It is likely that mushroom compost contains populations of beneficial microbes that are antagonistic to, or feed on, various species of fungi.
Preemergence Control of Doveweed (Murdannia nudiflora) in Container-Grown Nursery Crops
Authors: Walker Lela C. , Neal Joseph C. , Derr Jeffrey F.
Published: August 2020

Preemergence herbicides were evaluated for control of doveweed (Murdannia nudiflora), a summer annual weed of increasing importance in nurseries of the southeastern United States. In the first experiments, broad-spectrum nursery herbicides OH2 (oxyfluorfen + pendimethalin), Snapshot TG (isoxaben + trifluralin), and BroadStar (flumioxazin) were compared. OH2 and Snapshot provided poor and variable control whereas BroadStar controlled doveweed 82 to 100%. In the second set of experiments, recommended rates of all major active ingredients labeled for use in container nursery crops and landscape plantings were compared for control of doveweed. Doveweed was controlled ≥ 95% by BroadStar, Pennant Magnum (s-metolachlor), and Tower (dimethenamid-p). Barricade (prodiamine), Dimension (dithiopyr), Gallery (isoxaben), OH2, Pendulum (pendimethalin), Regal O-O (oxyfluorfen + oxadiazon), Ronstar (oxadiazon), Rout (oxyfluorfen + oryzalin), Showcase (trifluralin + isoxaben + oxyfluorfen), Snapshot TG, and Surflan (oryzalin) did not control doveweed.
Application Rate and Treatment Interval Influence the Efficacy of Heritage Fungicide for the Control of Alternaria Leaf Spot on Marigold
Authors: Hagan A.K. , Akridge J.R. , Bowen K.L.
Published: August 2020

Efficacy of Heritage 50WG (azoxystrobin) over a range of application rates and treatment intervals was compared with Daconil Weather Stik 6F (chlorothalonil) and Eagle 40W (myclobutanil) for the control of Alternaria leaf spot (Alternaria tagetica) in a simulated landscape planting of marigold in southwest Alabama. When applied at 2-week intervals, all rates of Heritage 50WG gave better disease control in all four years than Daconil Weather Stik 6F or Eagle 40W, applied on the same schedule. In two of three years, weekly applications of Daconil Weather Stik 6F decreased Alternaria leaf spot severity compared with the non-fungicide treated control, but when applied at 2-week intervals, disease levels were similar to the non-fungicide treated control in two of four years. Typically, Alternaria leaf spot intensified when Heritage 50WG application rates declined from 0.16 to 0.04 g ai·liter−1 and treatment intervals increased from 2-to 4-weeks. At the 0.04 g ai·liter−1 rate of Heritage 50WG, disease control was usually better at the 2-than at the 3-and, particularly, 4-week treatment schedule. Regardless of the level of disease pressure, Heritage 50WG at 0.08 and 0.16 g ai·liter−1 when applied at 3-week intervals consistently gave effective control of Alternaria leaf spot on marigold.
Monitoring Flight Activity of Ambrosia Beetles in Ornamental Nurseries with Ethanol-Baited Traps: Influence of Trap Height on Captures
Authors: Reding Michael , Oliver Jason , Schultz Peter , Ranger Chris
Published: August 2020

Ethanol-baited bottle traps were used to monitor spring flight activity of the ambrosia beetles Xylosandrus crassiusculus and Xylosandrus germanus in Ohio, Tennessee, and Virginia. The traps were deployed at three different heights to determine if height influenced captures. X. germanus was captured in all three states, while X. crassiusculus was captured in TN and VA only. Traps 0.5 m above the ground captured more X. germanus than traps at 1.7 or 3.0 m. Traps 0.5 or 1.7 m above the ground captured more X. crassiusculus than traps at 3.0 m. In TN and VA, first activity of X. crassiusculus and X. germanus occurred from mid-March to early April. In OH, first activity of X. germanus occurred early to mid-April. Analysis of attacks by X. germanus on Cornus florida revealed that more than 90% of the attacks occurred on the main trunk within 1 m (3 ft) of the ground. Monitoring will be most effective when traps are suspended 0.5 or < 1.7 m above the ground for X. germanus or X. crassiusculus, respectively. To detect first flight of X. crassiusculus or X. germanus, traps should be deployed by early to mid-March in TN and VA and late March in OH.
Use of Processed Biofuel Crops for Nursery Substrates
Authors: Altland James
Published: August 2020

Loblolly pine (Pinus taeda) bark availability has decreased, causing shortages in inventory and increased prices for pine bark substrates. One potential alternative to pine bark is the use of biofuel or biomass crops that can be grown locally, harvested, and processed into a suitable substrate. The objective of this research was to assess the suitability of several biofuel crops as alternatives to pine bark in nursery substrates using annual vinca (Catharanthus roseus) as a model crop. Across two experiments, switchgrass (Panicum virgatum), willow (Salix spp.), corn (Zea mays) stover, and giant miscanthus (Miscanthus ×giganteus) were processed through a hammermill equipped with a 0.95 cm (0.375 in) screen. Pine bark was used as a control. Substrate materials were used either alone, amended with 20% (v/v) sphagnum peat moss, or amended with 20% (v/v) sphagnum peat moss and 10% (v/v) municipal solid waste compost. Biofuel-based substrates tended to have greater air space and less container capacity than pine bark substrate. Amending with peat moss, or peat moss and municipal solid waste compost reduced air space and increased container capacity of all substrates. Substrate pH of biofuel-based substrates was higher than pine bark substrates, and was neutral to slightly alkaline. Amending with peat moss reduced pH of biofuel substrates to levels considered more ideal for annual vinca growth. Foliar calcium, magnesium, and iron levels were low across all treatments, although visual foliar deficiency symptoms were not apparent. Shoot growth was greatest in switchgrass and pine bark substrates. Plant growth differed among biofuel and pine bark substrates; however, all plants were considered marketable at the conclusion of the experiment. Modification of chemical and physical properties for each substrate type will be necessary.
Evaluation of a Single Application of Neonicotinoid and Multi-Application Contact Insecticides for Flatheaded Borer Management in Field Grown Red Maple Cultivars
Authors: Oliver J.B. , Fare D.C , Youssef N. , Scholl S.S. , Reding M.E. , Ranger C.M. , Moyseenko J.J. , Halcomb M.A.
Published: August 2020

Two trials evaluated insecticides for flatheaded borer control and effect on red maple (Acer rubrum L.) cultivar growth over 4 years. Chrysobothris femorata (Olivier) was the only species reared from borer damaged maples during the study. Soil-applied systemic insecticides (acephate, imidacloprid, clothianidin, dinotefuran, and thiamethoxam) and trunk-applied contact insecticides (chlorpyrifos and bifenthrin) were tested. In the 2005 trial, a one-time drench of Allectus (imidacloprid + bifenthrin) or Discus (imidacloprid + cyfluthrin) provided 2 to 4 years of protection with ‘Autumn Flame’ and ‘Franksred’ from C. femorata. Soil-applied experimental imidacloprid tablets prevented borer damage in the third and fourth post-treatment years, but were not as effective as imidacloprid drenches in the first two years. Soil applied acephate tablets, chlorpyrifos (Dursban 4E) trunk sprays, or untreated control plants had borer damage each year, which totaled up to 41.7% damage by year 4 in ‘Autumn Flame’. Trunk diameter growth and tree canopy size was greater with Discus drench or imidacloprid tablet treatments than other treatments. In the 2006 trial, drenches of Allectus, Discus, or Safari 20SG (dinotefuran) applied in May and Discus or Arena 50WDG (clothianidin) drenches applied in March provided complete protection from C. femorata the first year in ‘Fairview Flame’, ‘Franksred’, and ‘October Glory’. Discus (March) drench provided four years of complete protection among the three cultivars, while other neonicotinoid drenches had 3.7–6.3% (Arena March), 3.7–12.5% (Arena May), 0–6.3% (Discus May), 0–10.3% (Safari), and 12.5–20.5% (Flagship) total damage. Ineffective treatments included an experimental imidacloprid gel (7.4–18.8% damage), acephate tablets (18.5–75.0%), Onyx Pro Insecticide (5.1–18.8%), Dursban 2E (11.1–31.3%), one imidacloprid tablet (15.4–43.8%), or untreated plants (32.1–41.0%). This study demonstrates a single application of some neonicotinoid treatments can provide multi-year C. femorata prevention, increased maple trunk growth, and provide borer protection superior to trunk sprays.
Prevalence, Distribution and Identification of Phytophthora Species from Bleeding Canker on European Beech
Authors: Nelson Angela H. , Weiland Jerry E. , Hudler George W.
Published: August 2020

While bleeding canker of European beech trees (Fagus sylvatica) has long been recognized as a problem in Europe and North America, the cause in the northeastern United States has not been clear. To resolve this, we surveyed for disease prevalence on European beech, identified the pathogens involved, proved their pathogenicity, compared protocols for pathogen detection, and conducted a soil assay to determine pathogen presence in soil surrounding established trees in residential and commercial landscapes in New York, Pennsylvania, Maryland, Connecticut and Massachusetts. Approximately 40% of surveyed trees had bleeding cankers. While Phytophthora cactorum, P. gonapodyides, P. cambivora and two newly described species, P. citricola I and P. plurivora, were recovered from symptomatic tissue, P. citricola I and P. cactorum were most prevalent. All caused disease when artificially inoculated into European beech sapling stems, although P. cambivora and P. gonapodyides produced significantly smaller lesions. Recovery of the pathogen from symptomatic tissue using selective media, the preferred method of diagnosis, was significantly higher in the fall. ELISA detection was more successful and worked regardless of season, but did not allow identification to the species level. All five Phytophthora species were found in soil surveys; P. cambivora was most common, followed by P. cactorum and P. citricola I. These results provide a foundation for building management strategies to protect valuable specimens of European beech.
Seed Germination of Five Populations of Rhododendron vaseyi: Influence of Light and Temperature
Authors: Hebert Cary J. , Blazich Frank A. , LeBude Anthony V.
Published: August 2020

Seeds from five populations of Rhododendron vaseyi A. Gray (pinkshell azalea), representing the entire distribution of the species, 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), 8, 12, or 24-hr (continuous light). Germination was recorded every 3 days for 30 days. Responses to light and temperature of all populations were similar. Light was required for germination regardless of temperature. As photoperiod increased, germination increased for all populations with the alternating temperature partially compensating for the light requirement. The highest cumulative germination for all populations ranged from 51 to 67% and was achieved at 30/20C with a 24-hr photoperiod. These germination percentages, although at a moderate level, were due in part to rigorous cleaning and grading of seeds collected across a broad range of plants and growing conditions prior to initiation of the study, suggesting seed viability of R. vaseyi is inherently low.
Purple-leaved Japanese Barberry (var. atropurpurea) Genotypes Become Visually Indistinguishable from Greenleaved Genotypes (Berberis thunbergii DC.) at Low Light Levels
Authors: Lehrer Jonathan M. , Brand Mark H.
Published: August 2020

Japanese barberry (Berberis thunbergii DC.) is a popular nursery plant that has escaped from cultivation to establish invasive populations across the United States. Previous studies demonstrate that green-leaved feral plants adapt successfully to low light levels. The leaf color phenotype of purple-leaved Japanese barberry (Berberis thunbergii var. atropurpurea) seedlings grown under shaded conditions was studied to determine their appearance under low light conditions typical of wooded areas often invaded by barberry. Seedlings from B. thunbergii var. atropurpurea were grown in full sunlight and under three shade treatments (36, 50 and 72%). Seedlings were also grown in full sunlight and under two higher shade treatments (85 and 95%) in a second study. The hue angle of purple seedlings increased from a mean of 22.3 in full sun to 86.9 at 72% shade, reflecting a color change from violet-purple to green-umber. Foliage color also became more vivid and lighter as shading increased. All purple genotype seedlings appeared green when grown at 95% shade due to lack of anthocyanin production at this light exposure. Escaped barberry seedlings originating from landscape plants of var. atropurpurea may not be recognized as purple-leaved forms when they invade densely shaded woodland environments.
Susceptibility of Viburnum Species and Cultivars to Phytophthora ramorum
Authors: Widmer Timothy L.
Published: August 2020

Phytophthora ramorum causes ramorum blight on Viburnum species, which are commonly grown as ornamentals. This study evaluated 24 different species or cultivars for susceptibility to P. ramorum. Whole plants were inoculated with an NA1 isolate of P. ramorum and placed in dew chambers at 20C (68F). After 5 days, the percentage of necrotic leaves for each plant and the percentage of necrotic area for each leaf were calculated. The percentage of necrotic leaves per plant ranged from 96.1% (V. tinus) to 7.9% (V. opulus ‘Notcutt’) and the percentage of necrotic leaf area ranged from 73.0% (V. × carlcephalum ‘Cayuga’) to 2.4% (V. trilobum ‘Wentworth’). In addition, six species or cultivars were evaluated for their susceptibility to a EU1 isolate of P. ramorum. The isolate had a significant effect on three of the six species or cultivars tested, although one isolate did not always yield the greatest necrosis. Evergreen species and cultivars had a higher percentage of necrotic leaves and higher percentage of necrotic leaf area than semi-evergreen or deciduous species and cultivars. All Viburnum species and cultivars showed some degree of susceptibility to P ramorum.
Effect of Fall Fertilization on Freeze Resistance of Deciduous Versus Evergreen Azaleas
Authors: Henning Frank P. , Smalley Timothy J. , Lindstrom Orville M. , Ruter John M.
Published: August 2020

Plants that maintain their leaves throughout winter may respond differently to fall fertilization than deciduous plants. The effects of fall fertilization on cold hardiness, nutrient uptake, growth and flower production of evergreen versus deciduous azaleas were studied. Rhododendron canescens (Michx.) Sweet and R. × satsuki ‘Wakaebisu’ were grown in containers, outdoors in Athens, GA, under three fall fertigation regimes applied daily as 0.5 liter (0.13 gal) solutions containing: 1) 75 mg·liter−1 N from August 1 through September 29, 2) 75 mg·liter−1 N from August 1 through November 28, and 3) 125 mg·liter−1 N from August 1 through November 28. Stem freeze resistance was analyzed monthly November through March. Growth of azaleas that received 120 days of extended fertigation (August 1 through November 28) was not increased compared to azaleas that received 60 days of extended fertigation (August 1 through September 29). Growth of the two taxa did not differ in their response to fertilization treatments. The high rate of extended fertilization 125 mg·liter−1 N (from August 1 through November 28) reduced stem freeze resistance November through February, while the moderate rate of extended fertilization (75 mg·liter−1 N from August 1 through November 28) reduced azalea freeze resistance in December. Fall fertilization regimes did not produce differences in the timing of cold acclimation, or deacclimation of R. canescens and R. × satsuki. The high rate of extended fertilization promoted early budbreak of R. × satsuki and postponed flower budbreak of R. canescens. Flower production of R. canescens was not affected by fall fertilization, but the high rate of extended fertilization increased flower production of R. × satsuki compared to plants that received the moderate rate of fertilization 75 mg·liter−1 N from August 1 through September 29.
Investigating Consumer Preference for Biodegradable Containers
Authors: Yue Chengyan , Hall Charles R. , Behe Bridget K. , Campbell Benjamin L. , Lopez Roberto G. , Dennis Jennifer H.
Published: August 2020

Instead of virgin plastic, some growers are now using containers manufactured with alternative materials that can be planted directly in the soil and will degrade over time, thus eliminating the waste of disposing the pot into landfills. While previous studies have addressed certain aspects of consumer willingness to pay issue for biodegradable containers, this study specifically addresses consumer's perceived value for the containers themselves; that is, without the influence of the plant in the container. Analysis of the confidence intervals for wheat starch pots, rice hull pots, straw pots, coir pots, and peat pots reveal that they are overlapped, which indicates the price premiums participants are willing to pay for these five types of biodegradable containers do not significantly differ from each other. Consumers express a positive willingness to pay for several types of biodegradable containers relative to the standard virgin plastic container. There are two distinct levels or tiers that emerged with the first tier including coconut coir and peat pots, which received ratings in the same range as rice hull, straw, and wheat pots. A second, lower tier of similarly rated containers included the poultry feather, cow manure, and recycled plastic pots (relative to virgin plastic).
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

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

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

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.