bluuebunny/crossref_metadata_2025_split huggingface dataset:
Seed Germination of Two Populations of Rhododendron vaseyi: Influence of Light and Temperature
Authors: LeBude Anthony V. , Blazich Frank A. , Walker Lela C. , Robinson Sonya M. 
Published: August 2020

Abstract
Seeds of two populations of Rhododendron vaseyi A. Gray (pinkshell azalea) 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), ½, 1, 2, 4, 8, 12, or 24 hr. Germination was recorded every 3 days for 30 days. Light was required for germination regardless of population or temperature. As photoperiod increased, germination increased. The highest cumulative (30-day) germination percentages were realized at 30/20C with a 24-hr photoperiod; germination percentages for populations 1 and 2 were 45 and 50%, respectively. Temperature and photoperiod requirements for germination did not generally differ between the two populations.
Total Phenolic Content of Asian Elm Leaves and Host Plant Suitability for Gypsy Moth
Authors: Paluch Gretchen , Miller Fredric , Zhu Junwei , Coats Joel 
Published: August 2020

Abstract
The total phenolic content of foliage from 11 elm species and 2 cultivars was measured, and the relationship to gypsy moth developmental studies was determined. The 13 elms, Ulmus wilsoniana (Schneid.), U. japonica (Rehd.), U. glaucesens (Franch), ‘Accolade’, ‘Triumph’, U. davidiana (Planch), U. parvifolia (Jacq.), U. szechuanica (Fang), U. macrocarpa (Hance), U. chenmoui (Cheng), U. lamellosa (C. Wang et S.L. Chang, ex L.K. Fu), U. castaneifolia (Hemsl.), and U. gaussenii (Cheng), were grown at the Morton Arboretum, Lisle, IL and analyzed at the Pesticide Toxicology Laboratory, Iowa State University, Ames, IA. Significant differences were found in the phenolic content of the 13 elms surveyed. No significant differences were identified between gypsy moth larval longevity, pupal fresh weight, or percentage adult emergence with respect to total leaf phenolic content.
Influence of Irrigation Regime on Growth of Select Field-grown Tree Species in a Semi-arid Climate
Authors: Fox Lindsey , Montague Thayne 
Published: August 2020

Abstract
Over three growing seasons (2003 through 2005) we investigated stem area increase and shoot growth of field-grown (FG) trident maple (Acer buergeranum), hedge maple (A. campestre), autumn blaze maple (A. × freemanii ‘Autumn Blaze’), shantung maple (A. truncatum), Mexican redbud (Cercis canadensis mexicana), Texas redbud (C. canadensis texensis), white Texas redbud (C. canadensis texensis ‘Alba’), Oklahoma redbud (C. canadensis texensis ‘Oklahoma’), Washington hawthorn (Crataegus phaenopyrum), Arizona ash (Fraxinus velutina coriacea ‘Bonita’), Mexican plum (Prunus mexicana), chinquapin oak (Quercus muehlenbergii), English oak (Q. robur) trees subjected to three reference evapotranspiration (ETo) based irrigation regimes (100, 60, and 30% ETo). For maple trees, stem area increase did not differ between irrigation treatments. However, except for trident maple shoot elongation varied with irrigation level and species. Stem area did not differ between irrigation regimes for redbud trees, and shoot elongation was generally greatest for trees that received lower irrigation treatments. Depending upon species, oak stem area increase did not differ, or was greatest for trees that received greater irrigation. For each oak species, shoot elongation was influenced by irrigation level. For two of the three remaining species, stem area increase and shoot elongation differed according to irrigation volume. Despite three differing irrigation volumes, greatest growth was not always associated with increased irrigation volume. In addition, each species appears to be suited for regions with low precipitation and high pH soils.
Evaluation of Composted Poultry Litter as a Substrate Amendment for WholeTree, Clean Chip Residual, and Pinebark for Container Grown Woody Nursery Crops
Authors: Marble Stephen C. , Gilliam Charles H. , Sibley Jeff L. , Fain Glenn B. , Allen Torbert H. , Gallagher Tom V. , Olive John W. 
Published: August 2020

Abstract
WholeTree (WT) and clean chip residual (CCR) are potential new nursery substrates that are by-products of the forestry industry containing high wood content. Initial immobilization of nitrogen is one concern when using these new substrates; however the addition of composted poultry litter (CPL) to substrates containing high wood content could balance initial nitrogen immobilization and provide an inexpensive fertilizer source for growers. This study evaluated five woody nursery species being grown in WT, CCR, and pinebark (PB) with the addition of CPL or peat as a substrate amendment. Results indicate that these species can be grown successfully in WT and CCR substrates 6: 1 (by vol) with CPL. Use of CPL in WT and CCR substrates may provide an alternative to traditional PB plus peat based combinations in container plant production while providing poultry producers an environmentally sound means of waste disposal.
Vegetative Propagation of Oconee Azalea (Rhododendron flammeum) by Stem Cuttings and Mound Layering
Authors: Jones Jeff R. , LeBude Anthony V. , Ranney Thomas G. 
Published: August 2020

Abstract
Deciduous azaleas (Rhododendron L.) offer a range of desirable ornamental characteristics and can be valuable nursery crops. Availability in the nursery trade, however, can be limited by the lack of effective propagation protocols. Therefore, the objectives of this research were to develop and optimize vegetative propagation protocols for Oconee azalea, Rhododendron flammeum (Michx.) Sarg., utilizing stem cuttings or in-field mound layering. An optimal method for producing rooted stem cuttings with large root systems (&gt; 20 cm2) was to collect softwood stem cuttings from hedged stock plants followed by treatment with 10,000 ppm of the potassium salt (K-salt) of indolebutyric acid (K-IBA). Mound layering was also effective. Fifty percent of the stems on each mound resulted in rooted layers and approximately six layers were produced per mound regardless of mounding season (March or June), with or without wounding, or application of 5000 ppm K-IBA to stems prior to mounding in June. Both softwood cuttings and mound layering can be utilized to produce high quality plants.
Growth Retardant Use on Herbaceous Perennials Grown Under Night-Interrupted Lighting Outdoors in the Southern United States
Authors: Keever Gary J. , Kessler J. Raymond , Stephenson James C. 
Published: August 2020

Abstract
A study was conducted in 2002 and 2003 to determine if growth retardants could be used to suppress stem elongation of ‘Moonbeam’ coreopsis (Coreopsis verticillata L. ‘Moonbeam’) and ‘Goldsturm’ coneflower (Rudbeckia fulgida Aiton ‘Goldsturm’) when grown outdoors under nursery conditions in the southern United States without negating the benefits of earlier flowering from night-interrupted lighting (NIL). Night-interrupted lighting accelerated flowering of both cultivars without adversely affecting flower and flower bud counts or plant quality. However, plants grown under NIL generally were taller than plants grown under natural photoperiod (NP). When several PGRs [Cutless, B-Nine, B-Nine/Cycocel, Bonzi (2002 only), and Sumagic (2003 only)] were applied to plants under NIL, results varied with PGR type and concentration and year. Height of ‘Moonbeam’ coreopsis was effectively suppressed by 5000 or 7500 ppm B-Nine + 1500 ppm Cycocel in both years of the study and with 40 or 60 ppm Sumagic in the one year it was tested. Higher concentrations of Cutless and B-Nine suppressed height growth in 1 of 2 years, while Bonzi was ineffective. None of the PGR types or concentrations suppressed height growth of ‘Goldsturm’ coneflower to the level of the NP control in 2002. However, in 2003 when an additional application of Cutless and B-Nine were made, and Bonzi was replaced with Sumagic, applications of Cutless, B-Nine, B-Nine/Cycocel, and Sumagic all resulted in heights similar to or less than that of plants under NP with minimal effects on time to flower or flower and flower bud counts.
Response of Five Hydrangea Species to Foliar Salt Spray
Authors: Barbara Conolly N. , Bassuk Nina L. , MacRae Patrick F. 
Published: August 2020

Abstract
Hydrangeas are popular seaside plants; however, other than in anecdotal reports, there are no studies measuring their relative tolerance to salt spray. We examined response of ten cultivars and one subspecies of Hydrangea representing five species to foliar-applied salt solutions to recommend selections for seaside landscapes. Objectives were to determine whether there are differences in responses to salt spray among cultivars and species, and to determine whether varying concentrations of sodium chloride differentially damaged the plants. Plants were treated with a full-strength (ion concentration approximate to seawater) salt solution, a half-strength salt solution, or a control of tap water. Plants were rated after seven once-weekly applications based on percentage necrotic leaf area, an aesthetically and physiologically important symptom of damage. Cultivars of Hydrangea macrophylla and Hydrangea serrata were more tolerant of full-strength salt spray than cultivars of H. paniculata, H. anomala and H. arborescens. At half strength but not full strength, H. anomala ssp. petiolaris was most tolerant. Hydrangea macrophylla and H. serrata were the second most tolerant of half-strength applications. Hydrangea macrophylla or Hydrangea serrata should be planted where maritime salt spray will occur.
Cyclanilide Differentially Affects Branching in Red Maple Cultivars and Hybrids
Authors: Mickelbart Michael V. 
Published: August 2020

Abstract
Development of the canopy is an important aspect of ornamental shade tree production. Branching can be induced by pruning the apical meristem, but this process is time consuming and costly to growers. Cyclanilide is an auxin transport inhibitor that has been successfully used to eliminate apical dominance and increase branching in a number of tree species. In this study, we tested the effects of cyclanilide application in two years on branching, canopy form, and trunk diameter. Cyclanilide did not cause phytotoxicity symptoms in any cultivar at any rate. Two cultivars, Celebration® (Acer × freemanii A.E. Murray ‘Celzam’) and Sienna Glen® (Acer × freemanii ‘Sienna’) Freeman maples responded to cyclanilide treatments with increased primary and secondary shoots, whereas Red Sunset® red maple (Acer rubrum L. ‘Franksred’) and Autumn Blaze® Freeman maple (Acer × freemanii A.E. Murray ‘Jeffersred’) did not respond to any treatments. Responsive cultivars had approximately double the number of growing points and larger total branch length after second year applications, but this did not result in an increase in trunk caliper. Despite the increased number of shoots produced, overall canopy ratings did not differ among treatments. Cyclanilide had a limited affect on branching in red and Freeman maple whips. Furthermore, if growers choose to utilize this product, they should be aware that cultivar response is likely to vary, and initial testing should be done before making large-scale applications.
Host Plant Relationships of Leptodictya plana (Hemiptera: Tingidae)
Authors: Carr E. R. , Braman S. K. , Hanna W. W. 
Published: August 2020

Abstract
Leptodictya plana Heidemann is an emerging pest on ornamental grasses in the southern United States. Thirty-two selections of commercially available ornamental grasses and sedges and five trial accessions of Pennisetum purpureum were evaluated for susceptibility to L. plana feeding and oviposition. No-choice studies were conducted in a greenhouse by securing four lace bugs to leaf blades of each plant using clip cages. Lace bugs stayed attached for five days. Damage and number eggs were recorded. Choice studies were conducted in the laboratory by placing leaf blades from each genus of plant species into a large petri dish in a spoke pattern. There were no plants tested that consistently received zero percent damage in either trial. Plants that sustained the least damage included Acorus spp., Cordyline spp., and Panicum spp. Pennisetum spp. entries exhibited the highest overall percent damage and were the only genera of plants that supported oviposition.
Late Fall and Early Spring Application of Granular Preemergence Herbicide on a Fertilizer Carrier for Season-Long Crabgrass Control
Authors: Reicher Zachary J. , Weisenberger Daniel V. , Melichar Michael W. , Loughner Daniel L. , Borger Jeffrey A. , Naedel Matthew B. 
Published: August 2020

Abstract
Though sprayable preemergence herbicides will provide season-long control of crabgrass when applied in fall or early spring in the northern states, little work has been done with the now popular granular formulations of preemergence herbicide on a fertilizer carrier. Dimension (dithiopyr) or Barricade (prodiamine) on a fertilizer carrier were applied in October, November, March, April, May, or June in three trials and crabgrass control was monitored the summer following application. A single granular application of 0.56 kg ai·ha−1 (0.5 lb ai·A−1) of Dimension in November or March can provide control equivalent to that expected from typical mid-April applications. Barricade at 0.72 kg ai·ha−1 (0.65 lb ai·A−1) applied in November or March provided season-long crabgrass control equivalent to traditional mid-April application timing, though season-long crabgrass control from a November application of Barricade at 0.72 kg ai·ha−1 (0.65 lb ai·A−1) can be improved by a sequential May application of 0.28 kg ai·ha−1 (0.25 lb ai·A−1). Adding a sequential May application of Dimension at 0.28 kg ai·ha−1 (0.25 lb ai·A−1) only minimally improved crabgrass control over a November Dimension application at 0.56 kg ai·ha−1 (0.5 lb ai·A−1). Granular formulations of preemergence herbicide on a fertilizer carrier applied in November or March can provide season-long control similar to when applied at the traditional timing in mid-April in the Midwest and Mid-Atlantic regions of the United States. However, it is important for season-long crabgrass control to use the high label rate or follow with a sequential application in early summer if lower rates are used in the fall.
Impact of Overseeded Grass Species, Seeding Rate and Seeding Time on Establishment and Persistence in Bermudagrass
Authors: Serensits Thomas , Cutulle Matthew , Derr Jeffrey F. 
Published: August 2020

Abstract
Cool-season grass species are often overseeded into bermudagrass turf for both aesthetics and functionality during the winter months. When the overseeded grass persists beyond the spring, however, it becomes a weed. Experiments were conducted to evaluate overseeded grass species and seeding rate on turf cover during the fall, spring, and summer. The ability of perennial ryegrass, Italian ryegrass, and hybrid bluegrass to then persist in bermudagrass one year after seeding was determined. Both perennial ryegrass and Italian ryegrass produced acceptable ground cover in the spring after fall seeding. Hybrid bluegrass did not establish well, resulting in unacceptable cover. Perennial ryegrass generally had the most persistence one year after seeding, either because of the survival of plants through the summer or because of new germination the following fall. The highest cover seen one year after seeding was 24% with perennial ryegrass in the 2005 trial. Maximum cover seen with Italian ryegrass and hybrid bluegrass 12 months after seeding was 19 and 8%, respectively. Seeding perennial or Italian ryegrass in February achieved acceptable cover in spring in the first trial but not the second. Persistence the following fall, however, was greater in the second trial, suggesting new germination. Percent cover 12 months after seeding tended to increase as the seeding rate increased, also suggesting new germination the following fall. Although quality is lower with Italian ryegrass compared to perennial ryegrass, it transitions out easier than perennial ryegrass, resulting in fewer surviving plants one year after fall seeding.
The impact of substrate and irrigation interval on the post-transplant root growth of container-grown zinnia and tomato1
Authors: Roberts Bruce R. , Wolverton Chris , Janowicz Lauren 
Published: August 2020

Abstract
Substrate type and irrigation interval were studied to determine their impact on the post-transplant root growth of ‘Thumbelina' zinnia (Zinnis elegans Jacq.) and ‘Celebrity Hybrid' tomato (Lycopersicon esculentum Mill.). Seeds of both species were planted in 80 cm3 (2.7 fl oz) plug cells containing either Metromix 360™ (MM360) or Ball Professional Growing Mix™ (BPGM) and, following germination, the seedlings were transplanted into 450 cm3 (27.5 in3) plastic pots containing the same substrate. Evapotranspiration (ETO) was measured gravimetrically each day and the water lost via ETO added back to the substrate at intervals of 24, 48 or 96hr. For zinnia, root growth was consistently better for seedlings grown in BPGM, a substrate with greater water holding capacity and air-filled porosity. For plants grown in BPGM and irrigated every 48hr, root dry weight was significantly greater than it was for any of the remaining treatments. For tomato, root growth was greater for seedlings grown in BPGM and for transplants irrigated at 96 hr intervals; but, unlike zinnia, no significant interactions between substrate type and irrigation interval were observed. The results of this study show that root growth of plug-grown transplants can be improved by selecting a substrate with high porosity that allows for optimum oxygen and water exchange, and by extending the irrigation cycle to 48 hr (zinnia) or 96 hr (tomato).
Index words: irrigation scheduling, moisture stress, plant establishment, soilless growing media, transplant production
Species used in this study: ‘Thumbelina' zinnia (Zinnia elegans Jacq.); ‘Celebrity Hybrid' (Lycopersicon esculentum Mill.).
Decision Support Systems for Plant Disease and Insect Management in Commercial Nurseries in the Midwest: A Perspective Review1
Authors: Wallhead Matthew , Zhu Heping 
Published: August 2020

Abstract
Decision-support systems (DSS) are techniques that help decision makers utilize models to solve problems under complex and uncertain conditions. Predicting conditions that warrant intervention is a key tenet of the concept of integrated pest management (IPM) with the use of expert systems and pest models being characteristics of higher-level IPM. In this paper, potentials of four DSS including Ag-Radar, NEWA, RIMpro and Skybit to be used for ornamental nursery production are discussed. These systems were previously developed for orchard growers to effectively manage plant diseases and insects. Their development was based on the input of historical disease, insect pest and weather information. It will be an instrumental management aid to control insects and diseases in a timely manner if nursery growers can adaptively implement these orchard DSS into their production practices. In order to maximize effectiveness, however, next-generation DSS should consider the addition of consensus forecast models into user interfaces by combining the information generated from multiple independent models into a single spray-decision recommendation.
Index words: expert system, DSS, model prediction, forecast, insect, disease.
Poultry Litter Ash Rate and Placement Affect Phosphorus Dissolution in a Horticultural Substrate1
Authors: Wells Daniel E. , Beasley Jeffrey S. , Bush Edward W. , Gaston Lewis. A. 
Published: August 2020

AbstractPoultry litter ash (PLA) is a byproduct of bioenergy production and an effective P source for horticultural crops since it reduces P losses from container production due to its low P solubility. Experiments were conducted to determine effects of rate and placement of PLA on P loss from greenhouse crop production and growth and quality of two commonly-grown greenhouse crops, Verbena canadensis Britton ‘Homestead Purple' and Lantana camara L. ‘New Gold', by comparing two rates (140 and 280 g·m−3 P or 0.4 and 0.8 lb·yd−3) and two application methods (post-plant topdressed and pre-plant incorporated). Leachate-dissolved reactive phosphorus (DRP) concentrations were reduced by an average of 24% as P rate was reduced from 280 to 140 g·m−3, but were 134% less on average when PLA was topdressed instead of incorporated. Foliar P concentrations were less 33% and 44% for verbena and lantana, respectively when plants were topdressed compared to incorporated. Shoot biomass of verbena and lantana was 9% and 24% greater, respectively, when incorporating instead of topdressing PLA. As a P source, PLA should be pre-plant incorporated within the substrate at a total P rate between 140 g·m−3 (0.4 lb·yd−3) and 280 g·m−3 (0.8 lb·yd−3).Index words: phosphorus, poultry litter ash, Verbena canadensis Britton ‘Homestead Purple', Lantana camara L. ‘New Gold', dissolved reactive phosphorus.Species used in this study: ‘Homestead Purple' verbena (Verbena canadensis Britton); ‘New Gold' lantana (Lantana camara L.).
Comparing Closed Chamber Measures of Ammonia Volatilization from Kentucky Bluegrass Fertilized by Granular Urea1
Authors: Schlossberg Maxim J. , McGraw Benjamin A. , Hivner Kyle R. 
Published: August 2020

Abstract
Easy handling and low unit N cost make prilled urea (46-0-0) a popular fertilizer. While incomplete recovery of granular urea applications by turfgrass is documented, practical guidance for small-plot field assessment of ammonia (NH3) volatilization remains limited. Our objectives were to (i) develop a method for field-implementation of closed flux/dynamic chambers to measure ammonia emission over a 3-day period following granular urea application to turfgrass, and (ii) infer the significance of said measures to levels arising from simultaneous static-chamber measures. A Kentucky bluegrass (Poa pratensis L. ‘Midnight’) lawn was treated with granular urea-N at a rate of 0 or 43 kg.ha−1 (38 lb/A) twice in both 2014 and 2015. Flux chamber measures of mean ammonia volatilization from urea-N fertilizer applied 3 days previous exceeded simultaneous static chamber measures by a factor of 17. Relative to static, the closed dynamic/flux chamber system described affords a more precise and efficient method for measuring ammonia volatilization from small field plots. Furthermore, over a 3-day period of dry conditions and ambient temperatures fluctuating between 10 and 31 C (50 and 88 F), as much as 23.1% of a granular urea application broadcast over a Kentucky bluegrass lawn can be volatilized as ammonia.
Index words: flux, gaseous emissions, methods, nitrogen, static, turfgrass.
Species used in this study: ‘Midnight' Kentucky bluegrass (Poa pratensis L.).