Kennett Square, PA, United States
Kennett Square, PA, United States

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Evans M.R.,University of Arkansas | Taylor M.,Longwood Gardens Inc. | Kuehny J.,Louisiana State University
HortTechnology | Year: 2010

The vertical dry strength of rice hull containers was the highest of all containers tested. Plastic containers and paper containers had similar vertical dry strengths. Containers composed of 80% cedar fiber and 20% peat (Fertil), composted dairy manure (Cowpot), and peat had lower dry vertical dry strengths than the aforementioned containers but had higher vertical dry strengths than those composed of bioplastic (OP47), coconut fiber, and rice straw. Rice hull containers and paper containers had the highest lateral dry strengths. Rice straw, Cowpot, and plastic containers had similar dry lateral strengths, which were significantly higher than those of OP47, Fertil, coconut fiber, and peat containers. Highest dry punch strengths occurred with traditional plastic and Cowpot containers, while the lowest dry punch strengths occurred with OP47, Fertil, coconut fiber, peat, and rice straw containers. Plastic, rice hull, and paper containers had the highest wet vertical and lateral strengths. Plastic containers had the highest wet punch strength, while Fertil, Cowpot, and peat containers had the lowest wet punch strengths. When saturated substrate was placed into containers and the substrate surface and drainage holes were sealed with wax, plastic, OP47, and rice hull containers had the lowest rates of water loss per unit of container surface area, while peat, Fertil, and rice straw containers had the highest rates of water loss per unit of container surface area. The amounts of water required to produce a geranium (Pelargonium × hortorum) crop were significantly higher and the average irrigation intervals were shorter for peat, Fertil, coconut fiber, Cowpot, and rice straw containers than for traditional plastic containers. The amounts of water required to produce a geranium crop and the average irrigation intervals were similar among plastic, rice hull, and OP47 containers. Algal and fungal coverage on the outside container walls averaged 47% and 26% for peat and Fertil containers, respectively, and was higher than for all other containers tested, which had 4% or less algal and fungal coverage. After 8 weeks in the field, Cowpot containers had decomposed 62% and 48% in the Pennsylvania and Louisiana locations, respectively. Peat, rice straw, and Fertil containers decomposed 32%, 28%, and 24%, respectively, in Pennsylvania, and 10%, 9%, and 2%, respectively, in Louisiana. Coconut fiber containers had the lowest level of decomposition at 4% and 1.5% in Pennsylvania and Louisiana, respectively.

Taylor M.D.,Longwood Gardens Inc. | Kreis R.,Cornell University | Rejto L.,University of Delaware
HortScience | Year: 2016

The pH of peat moss generally ranges from 3.0 to 4.0 and limestone is typically added to raise pH to a suitable range. Compost is also used as a substrate component and typically has a high pH of 6.0 to 8.0. When using compost, lime rates must be reduced or eliminated. The two objectives of this study were to determine the resulting pH of substrates created with varying amounts of limestone and compost and assess the impact of the various amounts of limestone and compost on pH buffering capacity. Compost was created from a 1:1:1 weight ratio of a mixture of green plant material and restaurant food waste: horse manure: wood chips. The first experiment was a factorial design with five compost rates (0%, 10%, 20%, 30%, and 40% by volume), four limestone rates (0, 1.2, 2.4, and 3.6 g·L-1 substrate) with five replications. The experiment was conducted three times, each with a different batch of compost. With 0 lime, initial substrate pH increased from 4.5 to 6.7 as compost rate increased. This trend occurred at all other lime rates, which had pH ranges of 5.2–6.9, 5.6–7.0, and 6.1–7.1 for rates of 1.2, 2.4, and 3.6 g·L-1 substrate, respectively. Substrate pH increased significantly as either compost or lime rates increased. The second experiment was a factorial design with four compost rates by volume (0%, 10%, 20%, and 30%), the same four limestone rates as Expt. 1, and five replications. Each substrate treatment was titrated through incubations with six sulfuric acid rates (0, 0.1, 0.2, 0.4, or 0.7 mol of H+ per gram of dry substrate). Substrates with a similar initial pH had very similar buffering capacities regardless of the compost or limestone rate. These results indicate compost can be used to establish growing substrate pH similar to limestone, and this change will have little to no effect on pH buffering capacity. © 2016, American Society for Horticultural Science. All Rights Reserved.

Amberger-Ochsenbauer S.,Staatliche Forschungsanstalt fur Gartenbau | Taylor M.,Longwood Gardens Inc. | Lohr D.,Staatliche Forschungsanstalt fur Gartenbau | Meinken E.,Weihenstephan-Triesdorf University of Applied Sciences
Acta Horticulturae | Year: 2012

Fertilizers containing urea-N are recommended for horticultural crops because of the lower EC of the nutrient solution compared to solutions with ammonium or nitrate fertilizers, but high supply of urea raises the risk of plant damage and of gaseous N loss. Plants of Pelargonium × hortorum 'Merkur' were potted in partially decomposed peat with low nutrient supply from a complete water soluble fertilizer (0.75 g L-1, N+P 2O5+K2O = 14+16+18). Plants were fertigated in an ebb-flow-system with nutrient solutions containing (mg L-1): 100 N, 16 P, 83 K, 8 Mg plus micro-nutrients. Nitrogen was applied as urea and ammonium nitrate at ratios of 0+100, 33+67, 67+33 and 100+0 per cent. The experiment was a factorial design with deionized water and tap water (electrical conductivity 0.7 dS m-1, acid capacity 5.8 mmol L-1, equivalent to 290 mg CaCO3 per litre) used with each fertilizer treatment. Increasing ratios of urea caused pH to increase and EC to decrease in the nutrient solutions. There was only a small effect (with tap water) or no effect (with deionized water) of urea on salt content and pH of the growing medium. Even with 100% urea in the nutrient solution, urea was rapidly decomposed in the growing medium. The fresh mass of plants was significantly impaired with increasing ratios of urea, if deionized water was used for fertigation. Even with 33% urea, plant growth was reduced compared to plants fertilized with 100% ammonium nitrate. In the tap water treatments urea only had a small negative effect on plant growth. Although the use of urea is an effective way to reduce EC in nutrient solutions, there is little or no influence on the content of soluble salts in the growing medium and even small amounts of urea may have a negative effect on growth of pelargonium.

North Carolina Aroboretum Society Inc. and Longwood Gardens Inc. | Date: 2010-12-07

Paper, cardboard, and goods made from these materials, namely, stationery, hand towels of paper, table napkins and table linens of paper, filter paper, paper handkerchiefs, toilet paper, paper banners, paper boxes, placards of paper or cardboard, mats, namely, paper place mats, paper mats, paper table mats, coin mats, paper floor mats, table mats of paper; packaging containers of paper, paper bags for packaging, gift bags, wrapping paper, calendars, paper for use in the manufacture of plant containers; treated paper for wrapping flowers, plants or floral displays; printed matter, namely, books, booklets, pamphlets, guides, newspapers, periodicals, brochures, leaflets, magazines or trade journals or articles therein, featuring test research or consumer information for children or adults, all in the field of horticulture, gardening and/or perfumes and fragrances; address books; posters, postcards; artists materials, namely, modeling clay, canvas panels, sketch-pads; paintbrushes; binders, paper embossers, printed instructional and teaching material in the field of education for children and/or adults, and further education in the field of horticulture, gardening and/or perfumes; plastic envelopes for notebooks and booklets, namely, protective plastic covers for books; plastic book or notebook covers, plastic booklet covers; paper schedules, namely, date books; books containing poetry; plastic materials for packaging, namely, sleeves in the nature of bags, bags, foils, paper tags, plant sleeve tags and labels of paper, cardboard or coated cardboard; advertising material, namely, models for advertisements being advertising signs of cardboard or paper.

Zale P.J.,Ornamental Plant Germplasm Center | Zale P.J.,Ohio State University | Zale P.J.,Longwood Gardens Inc. | Jourdan P.,Ornamental Plant Germplasm Center | And 2 more authors.
Journal of the American Society for Horticultural Science | Year: 2015

Phlox is an important genus of herbaceous ornamental plants previously targeted for germplasm development, characterization, and enhancement by the U.S. Department of Agriculture, National Plant Germplasm System. Among Phlox in cultivation, Phlox paniculata is the most widely grown and intensively bred species, but little is known about variation in genome size and ploidy of this species or of related taxa that may be used for germplasm enhancement. The objective of this study was to assess cytotype variation in a diverse collection of cultivars and wild germplasm of P. paniculata (subsection Paniculatae) and of related taxa in subsections Paniculatae and Phlox. The collection included 138 accessions from seven species and two interspecific hybrids. Flow cytometry was used to estimate holoploid (2C) genome sizes and to infer ploidy levels. Chromosome counts were made to calibrate ploidy with genome size for a subset of taxa. Most cultivars were diploid (2n = 2x = 14) and had mean genome sizes that did not vary between subsections Paniculatae (14.33 pg) and Phlox (14.23 pg) although size variation was greater among cultivars within subsection Phlox. Triploid cultivars of P. paniculata, with a mean genome size of 21.36 pg and mitotic chromosome counts of 2n = 3x = 21, were identified. Such triploids suggests previous interploid hybridization within this taxon. Five tetraploid (2n = 4x = 28) cultivars were found in subsection Phlox; all were selections of P. glaberrima ssp. triflora, and had a mean genome size of 25.44 pg; chromosome counts in one of these confirmed they were tetraploid. The putative hybrid Phlox Suffruticosa Group ‘Miss Lingard’ showed an intermediate genome size of 21.21 pg supporting a triploid, hybrid origin of this taxon. Mean 2C genome sizes among wild-collected accessions were similar to values reported for cultivars (Paniculatae = 14.59 pg, Phlox = 14.23 pg), but taxa in subsection Phlox exhibited greater variation that included two tetraploids identified among wild-collected accessions; one, of P. pulchra, had a mean genome size of 26.17 pg, representing the first report of polyploidy in the taxon. This is the first report on genome size for the majority of species in the study. Although genome size could not be used to differentiate taxa in subsections Paniculatae and Phlox, the data provide further insights into cytotype variation of Phlox germplasm useful for plant breeders and systematists. © 2015 American Society for Horticultural Science. All rights reserved.

Zale P.J.,Longwood Gardens Inc. | Robarts D.W.H.,Ornamental Plant Germplasm Center | Robarts D.W.H.,Ohio State University | Jourdan P.,Ornamental Plant Germplasm Center | Jourdan P.,Ohio State University
Scientia Horticulturae | Year: 2016

The eastern North American creeping phlox (Phlox subulata L.) is a widely cultivated flowering groundcover with a history of breeding and selection. Little is known about genome size variation and ploidy of P. subulata and related taxa. Mean holoploid (2C) and monoploid (1Cx) genome sizes and ploidy were analyzed with flow cytometry for a germplasm collection (n = 53) of 11 morphologically similar creeping phlox taxa from natural plant populations, cultivars and hybrids obtained from nursery sources, and the related Microsteris gracilis. Holoploid genome sizes of accessions from natural populations were more variable than cultivated taxa and ranged from 7.47 to 22.86 pg and corresponded to diploid (2n = 2x = 14) tetraploid (2n = 4x = 28), and hexaploid (2n = 6x = 42) levels, but most accessions were diploid and genome size ranged from 7.60 to 8.47 pg. Two tetraploid accessions were discovered, but hexaploids were limited to one population of P. subulata. Most accessions consisted of a single cytotype, but intrapopulation differences in holoploid genome size were found among P. subulata and P. nivalis. The monoploid genome size of M. gracilis differed significantly from all Phlox, supporting separation of the genera. All cultivar accessions were diploid with genome sizes similar to wild diploid P. subulata, however Phlox × procumbens had a mean genome size (8.73 pg) intermediate to parental taxa, P. stolonifera × P. subulata, supporting hybrid origin. Knowledge of cytotype variation in Phlox germplasm will be useful for plant breeders, systematists, and conservationists. © 2016 Elsevier B.V.

Perera D.,Mississippi State University | Trader B.W.,Longwood Gardens Inc.
HortScience | Year: 2010

Slow growth rate of plantlets, few micro-shoots per explant, and slow root growth rate are restrictions of in vitro propagation of poinsettia (Euphorbia pulcherrima Willd. ex Koltz). The purpose of this research was to develop an efficient in vitro proliferation technique for poinsettia 'Prestige™ Red'.Explants (apical buds and axillary buds) placed on Murashige and Skoog (MS) basal medium containing only 6-benzylaminopurine (BA) and combinations of BA and indole-3-acetic acid (IAA) mostly produced red callus, which is productive and some white and gray-green calluses at the base of plantlets after 1 month, whereas explants in amedium without plant growth regulators (PGRs) produced no callus. Addition of IAA into the rooting medium increased rooting efficiency; plantlets grown in half-strengthMS salts and vitamins with 28.5 μMIAA initiated rooting 11 days earlier than the plantlets grown with no PGRs. Optimization of PGR concentrations during poinsettia micropropagation helped resolve previous restrictions of in vitro poinsettia proliferation. Chemical names used: 6-benzylaminopurine (BA); indole-3-acetic acid (IAA).

Gajanayake B.,Mississippi State University | Trader B.W.,Longwood Gardens Inc. | Reddy K.R.,Mississippi State University | Harkess R.L.,Mississippi State University
HortScience | Year: 2011

Temperature affects reproductive potential, aesthetic, and commercial value of ornamental peppers (Capsicum annuum L.). Limited information is available on cultivar tolerance to temperature stress. An experiment was conducted using pollen and physiological parameters to assess high and low temperature tolerance in ornamental peppers. In vitro pollen germination (PG) and pollen tube length (PTL) of 12 morphologically diverse ornamental pepper cultivars were measured at a range of temperatures, 10 to 45 °C with 5 °C increments. Cell membrane thermostability (CMT), chlorophyll stability index (CSI), canopy temperature depression (CTD), and pollen viability (PV)were measured during flowering. From the modified bilinear temperature-PG and PTL response functions, cardinal temperatures (Tmin, Topt, and Tmax) for PG and PTL and maximum PG (PGmax) and PTL (PTLmax) were estimated. Cultivars varied significantly for PG, PTL, cardinal temperatures for PG and PTL, and all three physiological parameters. Cumulative temperature response index (CTRI) of each cultivar, calculated as the sumof 12 individual temperature responses derived fromPV, PGmax, PTLmax, Tmin, Topt, and Tmax for PG and PTL, CMT, CTD, and CSI were used to distinguish differences among the cultivars and classify for high (heat) and low (cold) temperature tolerance. Based on CTRI-heat, cultivars were classified as heat-sensitive ('Black Pearl', 'Red Missile', and 'Salsa Yellow'), intermediate ('Calico', 'Purple Flash', 'Sangria', and 'Variegata'), and heat-tolerant ('Chilly Chili', 'Medusa', 'Thai Hot', 'Explosive Ember', and 'Treasures Red'). Similarly, cultivars were classified for cold tolerance as coldsensitive, moderately cold-sensitive, moderately cold-tolerant, and cold-tolerant based on CTRI-cold. 'Red Missile' and 'Salsa Yellow' were classified as cold-tolerant. Cultivar screening using pollen parameters will be ideal for reproductive temperature tolerance, whereas physiological parameters will be suitable for screening vegetative temperature tolerance. The identified heat-and cold-tolerant cultivars are potential candidates in breeding programs to develop new ornamental and vegetable pepper genotypes for high and low temperature tolerance.

At least three major gardens or arboreta in the USA have experienced periods of significant decline and death of mature Taxus (yews) in the landscape. The symptoms displayed on declining plants are described as chlorosis of the needles, partial defoliation, and death of some of the branches. Eventually, the entire plant may die, but they are typically removed before reaching this stage. Information on managing mature Taxus in the landscape is limited. The objective of this article is to review the literature on Taxus cultural practices and use the information to develop best management practices for Taxus in the landscape. Soil moisture is the most critical factor for health of plants in the landscape. Saturated soils create anaerobic conditions for roots and create an environment ideal for root infection by Phytophthora cinnamomi, the major root pathogen affecting Taxus. During planting, proper site selection and well-drained soil are crucial for the long-term survival of plants. After planting, irrigation should be managed to avoid saturated soil. Management from a nutritional standpoint is poorly understood. Maintaining an appropriate pH of 6.0 to 7.0 and fertilizing plants based on soil and tissue testing is recommended. More research needs to be done to determine optimal fertilization rates and appropriate nutrient concentration in tissue and in soil. When plants become symptomatic, soil should be tested for P. cinnamomi. If the fungus is present, appropriate chemical controls should be used. ©2014 International Society of Arboriculture

Longwood Gardens Inc. | Date: 2010-09-07


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