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Publications (73)
Natural swimming pools (NSPs) rely on the interaction of bog vegetation, bacteria, and substrate to maintain water quality. Nitrogen (N) and phosphorus (P) levels in NSPs are critical due to their involvement in eutrophication. We conducted a 15-week greenhouse study to address the significant literature gap on nutrient removal capabilities of subs...
The use of plastics has revolutionized the greenhouse industry. Plastic is used for everything from the exterior greenhouse coverings, or claddings, to structural components, to nearly all aspects of the interior production systems, including pots, trays, irrigation systems and almost everything else. It is safe to say that without the use of plast...
Green roof construction is constrained by cost of labor to install the plant material. Optimizing seed germination and establishment could significantly reduce installation costs but would require specific growing conditions that are difficult to provide during installation. Plants of the stonecrop (Sedum) genus are commonly used for the roof top b...
Experiments were performed from June 2014 to May 2015 at Penn State University’s greenhouse facilities in order to understand the production capacities and financial viability of an innovative growing system referred to as the Rotating Living Wall produced by GreenTowers, a student innovation/entrepreneurship team. The system is a six-foot vertical...
Green roof technology has been adopted in the United States as a specialized roofing system and as a sustainable technology capable of saving energy. Most of the previous thermal performance models for green roofs have had the main goal of quantifying these energy savings. However, until recently, none of the models had been fully validated with la...
Plants suitable for extensive green roofs must tolerate extreme rooftop conditions, and the substrates in which they grow must fulfill horticultural and structural requirements. Deeper substrates may retain more water for plants during dry periods, but will also weigh more, especially when near saturation. A study in central Pennsylvania was conduc...
This project evaluated green roofs as a stormwater management tool. Specifically, runoff quantity and quality from green and flat asphalt roofs were compared. Evapotranspiration from planted green roofs and evaporation from unplanted media roofs were also compared. The influence of media type, media depth and drought during plant establishment on p...
This project evaluated green roofs as a stormwater management tool. Specifically, runoff quantity and quality from green and flat asphalt roofs were compared. Evapotranspiration from planted green roofs and evaporation from unplanted media roofs were also compared. The influence of media type, media depth and drought during plant establishment on p...
The departments of Agricultural and Biological Engineering and Horticulture at the Pennsylvania State University have combined efforts to quantify the stormwater attenuation capabilities of extensive green-roof systems. This green-roof system consisted of a roof with a conventional flat-roof covering, a 0.5-in thick Enka-drainage layer, 3.5 in of p...
Green roofs are a best management practice for urban areas where land for traditional stormwater practices is unavailable. The two primary research objectives are the following: (1) To develop an effective media for green roofs that will improve roof runoff quality while maintaining the known water retention benefits of green roofs, and (2) To demo...
The focus of this research is the impact of green roofs on urban stormwater quality and builds on a laboratory study that evaluated several potential green roof media to produce a mix that produced the "best" overall reduction in pollutants from simulated rainwater. Because of the limitations of the laboratory testing, this second phase (field test...
Two separate studies using intercept survey methodology were conducted to define the components of a state plant promotional program - Pennsylvania Gardener Selects (PGS) - based on consumer preference and appeal. The first study, conducted 6 and 7 Mar. 2003 at the Philadelphia Flower Show in Philadelphia, Pa., involved 243 Pennsylvanians. Objectiv...
The postharvest quality of green chile fruit was compared after storage in 3 types of packages at 2 temperatures (24C and 8C). Package types were corrugated cardboard boxes, pressed cardboard trays overwrapped with VF-71 polyethylene, or low-density polyethylene (LDPE) bags. Fruit packaged in boxes or overwrapped trays had 24.8% and 10.1% weight lo...
Green roofing is a best management practice for urban areas where land for traditional stormwater practices is unavailable. However, it is unknown how effective they are at treating stormwater. The two primary research objectives are the following: 1. To develop an effective media for green roofs that will improve roof runoff quality while maintain...
Stormwater is a leading cause of water quality impairment in estuaries like the Chesapeake Bay. Green roofs are a potential best management practice for urban areas where land for traditional stormwater practices is unavailable. They are aesthetically pleasing, with excellent water retention ability. However, it is unknown how effective they are at...
The Penn State and North Carolina State University have combined efforts to
quantify the stormwater attenuation capabilities of extensive green-roof systems. The Annual Model
was applied to 28 years (1976-2003) of rainfall data in State College, PA and Raleigh, NC and
showed that 45 to 55% of the annual rainfall volume (depth) can be retained on th...
Green roofs on small 1.8 by 2.4 m buildings consisting of a conventional flat roof covering, a root barrier, a 12 mm thick Enka drainage layer, 89 mm of growth medium, 25 mm of porous expanded polypropylene (PEPP), and Sedum spurium planted 76 mm on center were evaluated to determine their potential to reduce stormwater impacts and roof surface tem...
A consumer-research study was conducted in two locations in Pennsylvania utilizing two survey methods: intercept and telephone. This study was designed to assess: 1) what national brand name plant material participants purchased in the past; 2) the consumer's awareness of the Pennsylvania Gardener Selects (PGS) program; and 3) the gardening habits...
Green roofs have been shown to reduce the stormwater runoff from buildings. In order to
model the reduced stormwater effect of green roofs, reliable estimates of ET from the CAM plants is
required. Greenhouse controlled environmental conditions were used to measure and predict ET
from CAM plants during winter and fall/spring regimes, along with cli...
Gardeners can provide the best insight to their gardening experiences and interests. In order to identify potential buyers of the state plant promotional program, Pennsylvania Gardener Selects (PGS), an intercept survey with 243 participants was conducted at the Philadelphia Flower Show on 6-7 Mar. 2003. Objectives were to better understand Pennsyl...
The Pennsylvania State University Medieval Garden (PSMG) showcases varieties of medieval plants used as ornamentals, food crops, medicinal ingredients, and for household purposes in a stylized setting representing a medieval garden. Since its installation, various colleges within the university as well as community groups have used the garden as an...
. In a previous study, three insect growth regulators, difl uben-zuron, pyriproxyfen, and fenoxycarb, were shown to reduce the emergence of western fl ower thrips (Frankliniella occidentalis) from potting medium under experimental conditions. Our objective was to evaluate the impact of potting medium applications of fenoxy-carb, difl ubenzuron, and...
With growing urbanization comes increased impervious areas and decreased open land for stormwater BMPs. Urbanization also increases stormwater runoff volumes and peak flow rates while decreasing infiltration and evapotranspiration. Green roofs consist of layers of specially designed and selected materials combined with shallow-rooted living plants...
The departments of Agricultural and Biological Engineering and Horticulture at the Pennsylvania State University have combined efforts to quantify the stormwater attenuation capabilities of a specific green-roof system. This green-roof system consisted of a 1:12 sloped roof with a conventional flat-roof covering, a 12- mm thick Enka-drainage layer,...
With growing urbanization comes increased impervious areas and decreased open
land for stormwater BMPs. Urbanization also increases stormwater runoff volumes and peak flow
rates while decreasing infiltration and evapotranspiration. Green roofs, sometimes called vegetated
roofs or eco-roofs, consist of layers of specially designed and selected mater...
Easter lily plants (Lilium longiflorum Thunb.), derived from tissue culture and grown continuously, were subjected to various photoperiod and chilling treatments. Lilies grown with daylength extended either with high-intensity discharge (HID) or incandescent lights flowered in the same number of days, but had more flower buds with HID lamps. Flower...
Anecdotal evidence suggests that constructed wetlands can remove odors from veal, dairy, and swine wastes (Murphy and George, 1997; McCaskey, 1995). However, the use of constructed wetlands as an odor control treatment will be more successful after malodor reduction in wetland systems has been quantified. This study quantified odor removal from swi...
The New Guinea Impatiens ( I. hawkeri Bull.) has become one of the most important spring crops for many growers. Rapid and continuous development of new and improved cultivars have lead to tremendous diversity in flower color, leaf color, plant size, and growth rate. Penn State has conducted large-scale garden evaluations of New Guinea Impatiens si...
Potential consumers were surveyed in the spring of 1996 to gain insight into preferences for flower and leaf color in New Guinea impatiens (Impatiens hawkeri Bull.). Survey participants indicated a preference for bright solid colors, and bicolor flowers. The most preferred solid flower colors were red-violet, and red. The least preferred solid flow...
In Spring 2000, a series of trials was initiated to determine if the fiber pots with holes can be planted, and how this technology might be used by nurserymen and landscapers. The experiment compared untreated (without copper amendment) containers with coppter treated pots containing only drainage holes, circular holes, or vertical slits. Hemerocal...
Constructed wetlands may be used for removal of high nutrient loads in greenhouse wastewater prior to discharge into the environment. Temperature affects both the physical and biological activities in wetland systems. Since nitrification and denitrification are temperature-dependent processes, effluent nitrate concentrations will fluctuate due to c...
Data obtained to date suggest that biological filtration using constructed wetlands is an alternative for treating greenhouse and nursery waste and irrigation water. Both planted and unplanted wetlands can effectively remove organic contaminants, reducing the potential for environmental contamination, chemical carryover from one crop to the next, o...
Temperature management has emerged as an important tool for plant height control in greenhouse production systems. This is particularly important in vegetable transplant production where chemical controls for plant height are limited or not legal. Plant height is a function of the number of nodes and the length of each internode, and both are stron...
Utilizing a combination of above-canopy and intracanopy lighting may prove highly beneficial in a Lunar Controlled Ecological Life Support System (LCELSS) as a means of increasing volumetric efficiency of plant growth. Intracanopy lighting was not found to be detrimental to plant tissue and production per plant when cowpeas were grown using sand cu...
The mycorrhiza is probably the most common symbiosis in which higher plants engage. More than 80% of higher terrestrial plants may be mycorrhizal.1 This may make the mycorrhiza the most common symbiosis in all of nature! Mycorrhizal fungi, those fungi that participate in the mycorrhizal symbiosis, are important and sometimes essential to their host...
Greenhouse operators are sensitive to energy costs related to heating, so operators are looking to alternative sources of energy like geothermal resources. The Rincon/Radium Springs and the Las Cruces-East Mesa geothermal areas of New Mexico offer a proven, environmentally benign, energy source that give substantial energy cost savings compared to...
Studies were conducted with raspberry fruit to isolate and identify naturally occurring yeasts for possible biological control activity against postharvest fungi. The yeasts identified were heterothallic or asexual Ascomycetes and Basidiomycetes. Biocontrol activity was compared with an isolate of Pichia guillermondi and a water-treated control. Af...
Poor post-production handling of bedding and seedling plants by mass-market outlets causes substantial quality reductions and product losses. Modified atmosphere packaging (MAP) may be a means to extend postharvest longevity and ease bedding plant handling. MAP, using heat sealed polyethylene bags, was tested with pansy, marigold, geranium, impatie...
Writing is an integral part of a career in horticulture. Most successful horticulturists write not only in communicating with peers, but also in keeping extensive journals or records of their activities. These tasks use different writing skills. Writing in horticulture classes should reflect, encourage, and provide practice in both types of writing...
Studies were conducted to determine postharvest longevity of field grown Desert Marigold ( Baileya multiradiata ) and perennial Aster (Aster bigelovii ) cut flowers. Flower stems were cut and placed into storage at 4, 7, 15 and 24C in the dark. Storage treatments included DI water, citric acid (CA), floralife (F), silver thiosulfate (STS) and modif...
Elongation characteristics of each internode on a lateral shoot of poinsettia (Euphorbia pulcherrima Klotz) `Annette Hegg Dark Red' were determined from pinching through anthesis for plants grown with 36 day/night temperature (DT/NT) combinations between 16 and 30C. The Richards function was used to describe the elongation of each internode. The fi...
Previous work has shown that container grown landscape plants use, and likely need, much less water than is typically applied. Therefore, studies were conducted to quantify the relationships between water loss and water stress responses using several drought tolerant (Cassia corymbosa, Leucophyllum frutescens, Salvia greggii) and traditional landsc...
Previous work has shown that container grown landscape plants use, and likely need, much less water than is typically applied. Therefore, studies were conducted to quantify the relationships between water loss and water stress responses using several drought tolerant (Cassia corymbosa, Leucophyllum frutescens, Salvia greggii) and traditional landsc...
Nephrolepis exaltata (L.) Schott 'Dallas Jewel' plants were grown for 92 days under 16 day/night temperature (DT/NT) regimes and two photoperiods for a total of 32 environments. Temperatures ranged from 15 to 30 ± 1.5C. Photoperiod was either 9 hours (short days) or 9 hours plus a 4-hour night interruption (long days) using incandescent lamps. Phot...
Lateral shoot growth and plant morphology of poinsettia ( Euphorbia pulcherrima Willd.) were influenced by the pinching technique used for apical meristem removal. Plants were pinched in one of four ways: 1) soft (removal of the apical meristem plus stem and leaf tissue associated with leaves ≤2 cm long); 2) medium (removal of the apical meristem p...
The effects of day temperature (DT), night temperature (NT) and photosynthetic photon flux (PPF), on rate of development and flower size were studied in chrysanthemum (Dendranthema grandiflora Tzvelev. cultivar ‘Bright Golden Anne’). DT and NT ranged from 10 to 30°C and PPF from 1.8 to 21.6 mol day−1m−2. Flower initiation did not occur after 100 sh...
Time required to complete four developmental phases in chrysanthemum ‘Bright Golden Anne’ ( Dendranthema grandiflora Tzvelev.) was determined under greenhouse conditions at constant temperature setpoints of 10, 15, 20, 25, 30, or 20 day/16C night. The four developmental phases were: I—start of short days to visible bud (2-mm-diameter terminal flowe...
The effects of photosynthetic photon flux (PPF), day temperature (DT) and night temperature (NT) on leaf number, leaf unfolding rate and shoot length were determined for chrysanthemum ( Dendranthema grandiflora Tzvelev. ‘Bright Golden Anne’) grown under short day (SD) conditions. A functional relationship was first developed to predict if flower bu...
Using saturation extract procedures, fifteen extractants were evaluated for their ability to remove B, Fe, Mn, and Zn from a peat and vermiculite (50:50% by volume) medium amended with three levels of micronutrients. A modified saturated media extract test procedure was developed in which 30 ml of .005M DTPA was added per 100 cc of sample to be ext...
Thesis (M.S.)--Michigan State University. Dept. of Horticulture, 1986. Includes bibliographies.
