bluuebunny/crossref_metadata_2025 huggingface dataset:
In Vitro Effects of Formaldehyde on Douglas Fir Pollen
Authors: Shirazi A.M. , Muir P.S.
Published: February 2019

There is increasing interest in using methanol and other alcohol fuels as an alternative energy source in the United States and developing nations. However, methanol-fueled vehicles have higher direct emissions of formaldehyde (HCHO) than gasoline-fueled vehicles, which has led to concern about increases in atmospheric concentration of HCHO. Formaldehyde at concentrations of 300, 600, 900, and 1200 μM reduced germination of hydrated Douglas-fir (Pseudotsuga menziesii) pollen in vitro. HCHO concentrations and pH in media containing pollen decreased during the 25-h incubation, with decreases proportional to HCHO concentration. This effect was not seen with heat-killed pollen, which suggests a detoxification mechanism. Ion leakage (measured as electrical conductivity) of pollen increased within 20 h in all HCHO treatments compared to controls. Stress also was indicated by TTC staining, which also decreased after HCHO treatment compared to controls.
Influence of Ambient UV-A and UV-B on Growth, Chlorosis, and Flavonoid Content of Cucumber
Authors: Krizek Donald T. , Mirecki Roman M. , Britz Steven J.
Published: February 2019

The influence of ambient UV radiation on growth, chlorosis, and flavonoid content was examined in four cultivars of cucumber (`Ashley', `Poinsett', `Marketmore', and `Salad Bush'). Plants were grown from seed in UV exclusion chambers consisting of UV transmitting plexiglass (10% T, 285 nm), lined with 3- or 5-mil Llumar (10% T, 399 or 404 nm) to exclude UV-A and UV-B, 5-mil polyester (10%T, 319 nm) to exclude UVB, or cellulose acetate (10% T, 291 nm) to transmit UV-A and UV-B. Plants were grown in 15 cm plastic pots containing vermiculite and were fertilized daily with nutrient solution. Despite their differential sensitivity to supplemental UV-B radiation, all four cultivars responded similarly to the exclusion treatments. After 19 to 21 days, plants grown under ambient UV-A and UV-B generally had less stem, leaf, and root biomass and less total height and total leaf area than those grown under conditions in which UV-A and UV-B or only UV-B was excluded. Flavonoid content, leaf number, and floral development were unaffected by UV. These findings demonstrate the extreme sensitivity of cucumber to current levels of solar UV radiation.
Chill-responsive Proteins in Blueberry: Are They Associated with Dormancy or Cold Acclimation?
Authors: Arora Rajeev , Rowland Lisa J.
Published: February 2019

To survive winters, woody perennials of temperate zone must enter into endodormancy. Resuming spring growth requires sufficient exposure to low temperature or chill units (CUs) in winter, referred to as chilling requirement (CR), which also plays a role in the development of freezing tolerance (cold acclimation; CA). Physiological studies on the breaking of dormancy have focused on identifying markers, such as appearance or disappearance of proteins in response to varying degrees of CU accumulation. However, whether these changes are associated with breaking dormancy or CA is not clear. We conducted a study, using greenhouse blueberry (Vaccinium section Cyanococcus) plants, to address this question Three blueberry cultivars (`Bluecrop', `Tifblue', and `Gulfcoast'), having CRs of ≈1200, 600, and 400 CUs, respectively, first were exposed to 4° for long enough to provide CUs equivalent to one-half of their respective CRs. This treatment resulted in CA. Plants were then transferred to 15C for 2 weeks (a treatment which should not negate CU accumulation but did result in deacclimation). Before and after each treatment cold hardiness (using a controlled freezing bath) and dormancy status (observe budbreak after placing shoots in water at 20C for 2 to 3 weeks) of floral buds were determined. Proteins were extracted from buds collected, simultaneously and separated by SDS-PAGE. To determine the association of dehydrin-like proteins with dormancy or CA, electroblots were probed with anti-dehydrin antibody. The relationship of protein and western blots data to cold acclimation and dormancy are presented.
The Effects of Salinity on Hibiscus syriacus and H. hamabo Seed Germination
Authors: Huh Moo R. , Kwack Beyoung H. , Perry Leonard P.
Published: February 2019

In this experiment, the effects of salinity from 0.0%, 0.5%, 1.0%, and 5.0 % NaCl on Hibiscus syriacus L. and Hibiscus hamabo Sieb. & Zucc. seed germination with various temperature and Ca treatments was investigated in petri dishes with 10 ml of distilled water or with the appropriate saline solution. At 11 days after treatment, the highest germination rate was obtained at 20C with H. syriacus and 25C with H. hamabo without NaCl and Ca treatments. At 25C, only H. hamabo seeds germinated with 1% NaCl, with dry and fresh weight increasing as Ca concentration increased. With 0.5% NaCl treatment, the germination rate of H. hamabo and H. syriacus increased as Ca concentrations (0.0, 13.35, and 133.5 mM) increased. Without NaCl treatments, hypocotyl and leaf length and width of H. syriacus were longer than those of H. hamabo; with NaCl treatments, the inverse was true.
Student Software Usage Patterns in a Computer-based Interactive Program for Woody Landscape Plant Instruction
Authors: Lindsey Christopher , Kling Gary , Zampardo Mark
Published: February 2019

UIPLANTS is a program developed under Microsoft Windows to help students in woody plant materials courses. Its many options include an encyclopedic format that displays 256-color high-resolution images of plant identification characteristics and ornamental features coupled with text, side by side image comparisons, “book markers” to return to selected screens, and a slide show that runs a display of images in a user-defined format. The system is being used to study how students learn information presented to them through computers and which program features are most effective in improving plant knowledge. Through computer logging of all student activity within the program and surveys given to the test groups, some basic usage patterns were derived. Students using the program with no incentive tended to use the program in a more comprehensive manner, switching back and forth between the slide show and encyclopedic entries with equal time spent in each. The comparison and “bookmark” features were used but less frequently. Half of the students, given an extra credit incentive based on time, followed this same usage pattern, but the other half simply used the slide show with minimal student–computer interaction.
The Influence of Plant Form on Human Health and Well Being
Authors: Lohr Virginia I. , Pearson-Mims Caroline H.
Published: February 2019

Research has shown that people respond physiologically and psychologically to scenes of urban and natural landscapes. Viewing nature has been associated with improvements in health, and there is evidence that people have a preference for certain tree forms. Human responses to different tree forms (spreading, columnar, and rounded) and nonliving urban elements were examined. Blood pressure, skin temperature, and emotional states of participants were measured while viewing computer-enhanced slides of urban and residential settings. Respondents were calmer when viewing trees than when viewing nonliving urban elements, and they expressed strong preferences for some tree scenes
Pesticides and the Baby Food Industry: A Case Study
Authors: Herner R.C. , Uebersax M. , Kabelka E. , Mazzucchelli R.
Published: February 2019

We present the decision case titled “One Size Does Not Fit All” developed for use in a capstone experience in the College of Agriculture and Natural Resources. The decision case requires an oral and written presentation of a solution to a problem posed in the case. Students work in small groups comprised of students with many majors within the college. The case study is based on the recent NRC report titled “Pesticides in the Diets of Infants and Children,” and the perceptions of the public concerning pesticides, baby food, and children. We outline how this case study was developed, the support material supplied to the students, and the experiences and observations that we have made as a result of using this case study. In addition, we outline how this case study could be modified to address other questions related to pesticides and food safety in a classroom setting.
Synergy between a Gerontology Program and a 4-H Informal Horticulture Education Program
Authors: Tennessen D.J. , Lalli V.A.
Published: February 2019

Youth interest in horticulture may be improved with the help of the elderly. The percentage of elderly people in the United States is growing at a greater rate than any other age group. The loss of life decision-making capabilities and the control of retirement home environments can lead to stress and depression. To counteract this problem, some institutions have used horticulture or pet therapy as tools to improve the quality of life for the elderly. We describe a 4-H horticulture education program that depends on mentoring skills of older adults to deliver hands-on, experiential-based 4-H program. In Project Exploring Aging through Shared Experiences (EASE), Pillemer et al. (1994) used as a framework for an intergenerational gardening experience. Students learn basic horticulture concepts from and with senior citizens though hands-on activities in a setting that is similar to the well-established SERIES program. Projects range from single-event terrariums to on-going summer gardens.
Characterization of Leca Clay Pebbles as a Growing Medium for Geranium (Pelargonium hortorum) Stock Plant Production
Authors: Libran Mana , Williams David J.
Published: February 2019

Leca clay pebbles were characterized and tested as a possible growing-medium for use in floriculture production systems that recycle irrigation water. Leca clay pebbles are light porous particles made by heating clay. X-ray diffraction tests indicate that high manufacturing temperatures (1100C) result in final particles composed primarily of quartz. Water-holding capacity was determined by pressure plate apparatus at eight pressures. Leca particles that were 4 to 8 mm retained more water than particles sized 12 to 18 mm. The bulk density of the particles were 0.43 and 0.37 g/cc for the 48-mm and the 12- to 18-mm particles, respectively. The pH of the leca particles was 7.77. The cation exchange capacity of the leca particles was relatively low compared to a standard soilless growing medium of 1 pine bark: 1 peat: 1 perlite (by volume). Leca particles have a CEC of o.82 me/100 g Ca and 6.36 me/100 g K, where the CEC of the previously mentioned soilless.medium was 24.21 me/100g Ca and 30.08 me/100 g K. Leca clay pebbles were tested as growing medium for the production of geraniums (Pelargonium hortorum) stock plants.
Developing a Model System for Cost-effective Floriculture Extension Program Delivery through Greenhouse Crop Management Associations
Authors: Berghage Robert D. , Michael Alan , Orzolek Mike
Published: February 2019

Current and future plans for reductions in federal and state funding suggest that government supported programs must find ways to reduce costs while maintaining or expanding programs. The current model of extension, with an agent for each commodity in every county is not likely to survive. Furthermore, the days when university-based specialists could afford to make house calls also are probably limited. Yet, the need for extension support in the floriculture industry is as great as ever. Increased chemical costs and regulatory pressure are restricting grower options and making it increasingly important that information dissemination and technology transfer occur in timely and appropriate ways. To try to meet the needs of the floriculture industry in Pennsylvania, we have begun a program to help develop independent greenhouse crop management associations to work with milti-county and university-based extension specialists to improve program delivery to the member greenhouses. The first of these associations has been established in the Capital Region in central Pennsylvania and is providing IPM scouting and crop management services to member greenhouses. Development of associations and linkages with and the role of extension are discussed.
Trial Gardening in Cyberspace
Authors: Berghage Robert D. , Wolnick Dennis J. , Holcomb E. Jay , Erwin John E.
Published: February 2019

The Internet offers many new and unique opportunities to disseminate information. The development of the World Wide Web (WWW) and information browsers like Netscap, Mosaic, and simple-to-use server software like MacHTTP provides means to allow low-cost access to information, including pictures and graphics previously unavailable to most people. The Pennsylvania State Univ. variety trial garden annually tests >1000 plants. Information is gathered on garden and pack performance, and photos of superior plants and varieties are taken. To provide wider access to this information, we have begun development of a Cyberspace trial garden on the internet. This server contains a wide variety of garden trial information developed from trials conducted in State College and Dauphin, Pa.. This server and a similar effort at Univ. of Minnesota are being constructed cooperatively. Hot links are provided between the server in Pennsylvania and the one in Minnesota, providing users with seamless access to information from both servers.
Our Experience on the Effect of Gene Stability and Expression on Development of Virus-resistant Fruits and Vegetables Expressing Genes from Different Viruses
Authors: Gonsalves Dennis
Published: February 2019

Our laboratory has focused on the development of virus-resistant plants through the use of pathogen-derived resistance. We have analyzed transgenic plants, including tobacco, cucumbers, melons, squash, chrysanthemum, tomato, papaya, and lettuce, that contain the coat protein genes of viruses belonging to the potyvirus, tospovirus, nepovirus, cucumovirus, and comovirus groups. Field and greenhouse trials have generally shown that resistance is not correlated to the expression level of the coat protein gene—in a number of cases, plants that expressed low amounts of coat protein showed excellent resistance. However, we have found that transgenic progenies from a particular plant often vary in their resistance to virus infection. These observations will be discussed as they relate to gene stability.
The Strengths and Weaknesses of Scheduling Irrigations Based on Soil Water Content Measurements and ET Models
Authors: Swietlik Dariusz
Published: February 2019

Several soil moisture measuring sensors are used to schedule irrigation of horticultural crops. However, without precise knowledge on root distribution, these devices may not provide accurate data on soil moisture conditions around the majority of roots. Also, some devices are expensive and/or require a tedious calibration and careful maintenance, limiting their use by growers. ET models have been successfully used for many crops grown in arid climates; however some models are not very precise and do not account for seasonal differences in plant water needs. Moreover, in humid regions it is difficult to assess the magnitude of rainfall contribution to the plant water needs particularly when only a part of the root system is irrigated. Research is needed to characterize plant variables which are useful for scheduling irrigation.
The Wild and the Beautiful: Exotic Sources for Improving Capsicum (Pepper)
Authors: Bosland Paul W.
Published: February 2019

The genus Capsicum provides a bountiful source of extraordinary genetic diversity with which to improve the cultivated species. Approximately 23 species are recognized within the genus. Five major cultivated species are derived from different ancestral stocks found in three distinct centers of origin. Mexico is the primary center for C. annuum, with Guatemala a secondary center; Amazonian for C. chinense and C. frutescens, and Peru and Bolivia for C. baccatum and C. pubescens. Several wild species are crossable to C. annuum, the most commercialized species. Capsicum inhabits a vast array of ecological zones. The wild species furnish a variation of mating systems, plant–animal interaction, patterns of speciation, and other intriguing biological features. However, their potential value for improvement of Capsicum cultivars is under-exploited. Such genetic resources clearly deserve more intensive investigation.
Organic Production of Angelica
Authors: Tremblay Nicolas , LaFlamme Lucette , Gosselin André
Published: February 2019

Angelica (Angelica archangelica) is a tall biennial grown for its root-bound active ingredients. A research was conducted to adapt conventional angelica production methods to organic principles and nordic growing conditions. Seeds should be stratified for 7 to 8 weeks before sowing and transplant production done in multicellular trays filled with compost-peat media and supplemented with organic soluble fertilization. A sequential sampling program was conducted to better-understand the dry matter and active ingredients accumulation patterns over the growing seasons. In light of these results, the recommended production schedule consists of a fall planting and a harvest the following fall. In this manner, both dry matter yield and active ingredient concentration in the root are improved. Root yields increase linearly with planting densities up to 111,111 plants/ha. After 5 years of research, most of the limiting factors have been studied and the problems solved. Our research clearly shows how much yield, quality, and profitability of a newly introduced crop can be improved when a comprehensive research program is implemented.
Organic Cultivation of Camomile in North America
Authors: Letchamo W. , Gosselin A.
Published: February 2019

Camomile (Chamomilla recutita Rauschert) is an annual plant from the Asteraceae. Camomile is one of the most frequently used medicinal plants, and has a commanding place in the world market. The flower heads are used in pharmaceutical preparations, and the cosmetic and beverage industries. The extracts from camomile flowers, to mention some, are known to have the most-effective sedative (3.29× compared to papaverin), antidepressive, tumor -protective, antiinflammatory, and accelerative properties in the regeneration of skin tissues. It is considered a panecia, due to its strong effects among many others, in the treatment of gastric ulcers, stomatology, respiratory complications, nephritis and nephrolithiasis (dilution of the kidney stones), and urinary bladder stones (cystolithiasis). Recently, successful research programs have been carried out to develop new camomile varieties with higher flower yield and better content of the active substances, suitable for mechanical harvesting under conventional cultivation. Apart from growing consumer demand for organically grown herbal products, the use of some herbicides and insecticides has resulted in the shifts of the content of active substances. The yield stability, content, and composition of the active substances under organic cultivation, particularly in areas with extreme climatic conditions, such as northern North America, should be investigated. We identified and introduced new camomile varieties and studied their suitability for organic field cultivation in Quebec, Canada. We studied over-wintering ability, yield potentials, and the content and composition of essential oil, flavonoids, and coumarins under field conditions. The physiology of the new varieties, particularly the relationship between photosynthesis and yield formation, and the accumulation of the active substances under different cultivation conditions remain to be studied.
Pest and Weed Control in Crops, A Non-chemical Approach
Authors: Csizinszky A.A.
Published: February 2019

Crops that are produced without manufactured fertilizers and protected from plant pests and weeds without manufactured chemicals are gaining in popularity among consumers. Non-chemical methods of plant protection, such as the development of biocides from plants, would be desirable for environmental and economic reasons and because of pesticide tolerance of some plant pathogens and insects. Extracts and their individual ingredients from several plant species have been used experimentally against plant pathogenic bacteria, insects, and weeds. There are problems, however, that make the use of biocides difficult: low concentration of active ingredients in the plants; purification of active ingredients from dozens of secondary compounds; instability of the active ingredients when exposed to light and air; and the mode of action is little understood or unknown. The technological and scientific advances that could allow the use of non-chemical based plant protection systems and the problems with such systems will be considered and discussed.
Computer Classification of Roots from Digitized Video Images
Authors: Stutte Gary W. , Stryjewski Elizabeth C.
Published: February 2019

Manual methods for estimating root length are tedious and time-consuming. Image capture and analysis systems can be used to obtain precise measurements of root length and growth angle. Root activity can also be determined through analysis of the mean pixel intensity of a digitized image. Both commercial (the IBM-compatible ICAS System) and public domain (the Macintosh-based NIH Image) image capture and analysis software have been used to analyze intact root systems. Examples of ICAS classification of hydroponic and soil-grown root systems will be presented. Advantages of the NIH Image software for analysis of micro-gravity experiments aboard the Space Shuttle will be discussed.
Use of Core Subsets in Developing Germplasm Collections of Clonally Propagated Crops
Authors: Grauke L.J. , Thompson T.E. , Forsline Philip , Hummer Kim
Published: February 2019

Core subsets have been formed in several clonally propagated crops; for pear (Pyrus), strawberry (Fragaria), mint (Mentha), currant (Ribes), blackberry (Rubus), blueberry (Vaccinium), apple (Malus), and pecan [Carya illinoinensis (Wangenh.) K. Koch]. Criteria for selecting entries into each core varies, as does the use each core receives. Core subsets have been selected for each of the major collections maintained at NCGR-Corvallis (pear, strawberry, mint, currant, blackberry, and blueberry). In general, core subsets include 10% of the full collection. Entries were selected on the basis of horticultural characteristics and species representation. Management of the collection is facilitated by recognition of core entries, which are frequently distributed. The 2500 accessions of the Malus collection are represented in a core subset of 200 accessions. Of those, 100 represent the 35 known species, while 100 accessions were selected from elite clones on the basis of horticultural characteristics. The core has been successfully used to find a superior virus indicator. Entries have been propagated in test orchards in five states. The core strategy was used to compare the pecan cultivar collection to seedlings from native populations throughout the species range. The analysis revealed gaps in the ex situ collection, and may have implications for in situ conservation. A core subset (26 cultivars) was selected by stratified sampling within the geographic regions to mirror the allele frequency of the cultivar collection, consciously including extreme expressions of each horticultural trait evaluated. The availability of the diverse subset has effected management and distribution.
Quantification of Dormancy—Physiological and Biochemical Approaches
Authors: Khan Anwar A.
Published: February 2019

Quantification of seed dormancy has been achieved by measuring physiological, biochemical, and molecular changes accompanying dormancy release, as well as dormancy development. At the physiological level, dormancy is quantified in terms of stratification time, strength of embryo covering structures, embryo growth potential, responsiveness to light, and to temperatures and other changes. At the biochemical level, dormancy has been related to hormone (abscisic acid, gibberellin, etc.) levels, respiratory activity, and other metabolic functions. At the molecular and cellular level, dormancy has been associated with RNA and protein synthesizing ability and with gene expression. Our recent studies with lettuce seeds using gibberellin biosynthesis inhibitors indicate that the amount of gibberellin produced during seed soak may mediate dormancy release and is quantitatively related to the level of dormancy. Examples of quantifiable changes associated with dormancy will be described. Whether a quantifiable change reflects a causal relationship with dormancy release or development, or is a consequence thereof, will be discussed.
Quantification of Seed Dormancy of Deciduous Orchard Species
Authors: Seeley Schuyler D.
Published: February 2019

Forcing plant material has long been used to determine dormancy intensity (DI) in woody species. Forcing with growth regulators may enhance this ability. Some forcing with naturally occurring hormones may be showing us the actual DI of certain materials. But, measurements of DI that use caustic, near-lethal treatments, or metabolic agents may be all or nothing breaking indicators acting on mechanisms other than the dormancy mechanism and thus not as useful in determining DI. It is possible to cause a meristem to break without completely breaking dormancy. Measurement of normal post-dormancy growth is necessary to determine the effect of a DI agent. DI breaking treatments that act on the dormancy mechanism can cause a temporary growth flush, but, unless the extent of that growth flush is measured and compared with the growth flush of the same normally broken plant material, its true effect remains unknown. In some plant material, the safest way to determine DI is to determine the chilling required to produce normal growth. This assumes that the vernalization requirement and temperature response curves are known for the plant in question. In peach, for instance, vernalization at 2C will cause seeds to germinate, but the resulting seedlings will be physiologically dwarfed. Vernalization at 6C or at 2C cycled with higher temperatures within the vernalization range results in normal seedlings. This indicates that, for chilling to progress normally, vernalization per se must be interspersed or concomitant with growth heat units. Vernalization, therefore, has a low temperature driven component and a heat requiring development and/or growth component. Vernalization driving conditions are slowly being elucidated. Each clarification requires modification of dormancy models. DI does not equal dormancy status!
Testing Petiole Sap for Nitrate and Potassium: A Comparison of Different Analytical Techniques
Authors: Rosen Carl J. , Errebhi Mohamed , Wenshan Wang
Published: February 2019

An important aspect of establishing critical sap nutrient concentrations for diagnostic purposes is to determine the accuracy and precision of the analytical method used. We compared a Cardy flat membrane NO3 electrode, a Hach portable NO3 electrode, and a Wescan N analyzer for their ability to determine NO3 concentrations in sap of potato petioles. The Hach and Wescan instruments require diluted sap, while nondiluted sap can be used with the Cardy. Nitrate-N concentrations in nondiluted petiole sap measured with the Cardy electrode were 100 to 200 mg·liter–1 higher than the other two methods. Using sap diluted with 0.15 M Al2(SO4)3 tended to lower Cardy NO3 readings to concentrations closer to the other methods, but made the procedure more complicated for practical use. We also compared a Cardy K electrode with flame emission spectroscopy for determining K concentrations in sap. Using nondiluted sap with the Cardy procedure resulted in K concentrations 1000 to 1700 mg·liter–1 lower than those determined by flame emission. Diluting sap with 0.15 M Al2(SO4)3 for use with the Cardy electrode resulted K concentrations similar to those determined by flame emission. Implications for using the electrodes for diagnostic purposes will be discussed.
Research and Field Experiences with Petiole Sap Testing of Vegetables and Strawberries in Florida
Authors: Hochmuth George J.
Published: February 2019

Vegetable producers are under increasing pressure to minimize production inputs such as water and fertilizers. Research on fertilizer placement and scheduling, soil testing, and drip irrigation fertigation has provided technologies to enable vegetable growers to produce profitable yields of high-quality vegetables while reducing nutrient inputs. Plant tissue testing has been an integral part of nutrient management on the farm. Although plant sap testing has been evaluated for more than 70 years, only recently has testing technology been developed to the point where farm use is facilitated. Researchers in several states, including Florida, have evaluated various methods for determining nitrate-N and K concentrations in petiole sap. Researchers in Florida have developed petiole sap sufficiency ranges for the major vegetable crops and strawberries, and these guidelines are widely used by vegetable growers and crop consultants as an aid for making informed fertilization decisions. In this workshop, research results and field experiences with fresh sap testing for N and K will be discussed, including field test equipment, testing methods, and current test applications.
Using Adobe Photoshop and CD-ROM to Enhance and Store a Greenhouse Slide Collection
Authors: Walter Virginia R.
Published: February 2019

Presenting slides as part of any horticulture course can be time-consuming and often does not allow students independent viewing. A CD-ROM format can store enough digitized images and text to allow students to systematically view images at their own pace and enhance the classroom instructors ability to communicate desired information rapidly. A Macintosh-formatted model using greenhouse images created from scanned slides will be demonstrated and methods of implementation will be discussed.
Utilizing Digital Images in Extension and Instructional Materials and Their Dissemination using Internet
Authors: McConnell James
Published: February 2019

Options for acquiring digital images are explored. Photo CDs, scanned images, and video capture are the most common sources of images. Photo CDs produce the highest-quality images, but require more time to get the digitized images due to commercial processing. For Photo CDs, the images are photographed with a 35-mm camera and sent for processing and digitizing. Slide and flat bed scanning is time consuming when working with bulk quantities of images. With live video capture, a video camera is directly connected to a computer and images are digitized in real time. Tape-recorded images can be also be used, but the image quality is less than live video. VWeb server allows rapid dissemination of the materials. This procedure greatly reduces the production time to a finished product, gives flexibility in revising publications and allows a greater variety of materials to be produced.
CD-ROM Delivers an Extensive Library of Plant Data
Authors: Gilman Edward F. , Davis Gregory L.
Published: February 2019

Horticulturists can access an extensive library of data, text, photographs, line drawings, and landscape designs from CD-ROM. In tests conducted in Florida, classroom students successfully accessed this library in a computer lab to study plant identification. This made it unnecessary to duplicate slides for student self-learning. It also builds confidence in students' ability to use computers. The Cooperative Extension Service and Divisions of Forestry in the southern states also have enjoyed access to this technology. Customers of their services have been pleased with the quick access to reliable information. Most are pleased with the information received over the telephone or during their visit to the office. Information generated by the computer programs on CD-ROM has been faxed, mailed. or hand-delivered to customers. Cooperative Extension employees and Master Gardeners are pleased with the quick, easy access to information. Many report that the programs have replaced the need to page through a large number of books to gain access to plant information. This saves time and gives employees a renewed sense of pride in their work.
Incorporating Hypertext Applications into Horticulture Educational Programs
Authors: Newman Steven E.
Published: February 2019

Hypertext applications have grown from highlighted index referencing tools used in “help” windows to sophisticated file sharing between many computers linked via the World Wide Web (WWW). Software such as Mosaic makes this link easy and convenient by using “Hypertext Markup Language” (HTML). Most universities and many companies have installed WWW servers and have provided disk space for general use. Horticulture departments and many botanical gardens across the country and all over the world are adapting to this technology by providing access to extension information sheets, newsletters, and selected manuscripts. Pesticide chemical manufacturers are also establishing WWW servers with the intent on providing rapid access to pesticide labels and material safety data sheets (MSDS). For local classroom use, HTML using a WWW server can provide an innovative and alternative means for delivering lecture material.
Water Status of Seeds
Authors: Taylor A.G.
Published: February 2019

Four topics are presented on the status of water in seeds; 1) methods to express moisture content (MC), 2) methods to determine MC, 3) relationship between relative humidity (RH) and MC, and 4) utility of water activity measurements in seeds. Seed MC is expressed on a fresh-weight basis in commerce and seed technology, while dry weight basis is used in physiological or biophysical literature. Conversion equations are available for the fresh and dry weight measurements. Moisture testing methods are grouped as primary and secondary. Primary methods are direct methods in which the water is removed and determined, while the secondary methods are indirect methods that rely on a chemical or physical characteristic that changes with MC. The oven method is the most common primary technique and the electronic moisture meter is widely used as a nondestructive secondary technique. The relation between RH and MC is known as an isotherm, and three zones of water binding are observed. The RH and the seed composition, in particular the lipid content, determines the MC. Seeds with low lipid content have a greater equilibrium MC than seeds with high lipid content. Water activity, defined as the ratio of water vapor of the seed over the water vapor of pure water at a particular temperature, is related to water potential in a log-linear relationship. Water activity (aw) can be used to define the water status of any species, regardless of composition.
Seed Storage—The Short and Long of It
Authors: Roos Eric E. , Vertucci C.W.
Published: February 2019

Practical experience has generally been the source of guidance for seed storage from one season to the next. Our ancestors soon realized that avoiding moist warm conditions and protecting seeds from predators was necessary if seeds were to survive till the next planting season. Simple experiments, using different combinations of temperature and seed moisture content and/or relative humidity, showed that much longer storage periods could be attained by lowering one or both of these factors. Drying seeds and storing them in air-tight containers, or even under vacuum, at subambient temperatures could produce longevities of years or even decades. Many myths were recorded in the popular literature about longevities of centuries or even millennia. Recent research on the biochemistry and biophysics of deterioration have led to new theories on longevity that have turned our thinking upside down. A discussion of both practicalities of storage and theoretical aspects will be presented. Simplified recommendations are proposed for determining the most cost-effective approach for seed storage under various environmental and economic conditions.
High-permeability Experimental Polyethylene Polymers for Modified-atmosphere Packaging
Authors: Gay Eric W. , Beaudry Randolph M.
Published: February 2019

O2 and CO2 permeabilities were determined for experimental polyethylene polymers (Dow Plastics, Freeport, Texas) in relation to low-density polyethylene (LDPE) films for the packaging of horticultural commodities. A stainless steel flow-through permeability cell was used to determine O2 and CO2 permeabilities at 0, 5, 10, 15, 20 and 25C for the polymers. Data were fitted to the Arrhenius' relationship and the Arrhenius' constant and energy of activation were determined. In addition, flow-through containers of sealed cherry tomatoes at room temperature were used to determine ethylene permeability of the polymers. The new polymers were several times more permeable than LDPE to O2, CO2, and ethylene. The results were incorporated into a model for predicting O2 concentrations over a temperature range for sliced apple fruit. The greater permeability of the new polymers will improve control of O2 and CO2 in modified atmosphere packages and enhance flexibility of package design.
The Impact of White-tailed Deer Browsing on Wisconsin Native Landscapes and Croplands
Authors: Weiss Laura
Published: February 2019

This research was done to examine the damage to vegetation due to white-tailed deer (Odocoileus virginianus). Deer damage is an alarming problem in the agricultural setting, but a growing concern is the “browsing damage” to the natural habitat. Forests and their undergrowth are not able to regenerate under the heavy browsing pressure. This is posing serious problems that are in the progress of being remedied.
Fertilizers and irrigation Techniques for Container Nursery Stock Production
Authors: Robinson-Hipple Laurie , Propsam Faye , Calkins James B. , Swanson Bert T.
Published: February 2019

Media fertility, plant nutrient availability, and subsequent plant nutrition are critical factors in the production of quality landscape plant materials. The method of mixing slow-release fertilizers into the media prior to planting is becoming more widespread. This study evaluates different controlled-release fertilizers, their rates of release, and three methods of irrigation regarding water-use efficiency and effects on plant growth performance. The combined effects of fertility and irrigation practices on nutrient loss to the environment are also being monitored. Although the ranking of fertility treatments, based on plant quality, varied among species, Woodace 21–4–10, Sierra 17–6–10, Sierra High N (24–4–6, Scotts 20–7–10, (270–26.67 lb/yd3), Woodace 20–5–10, Polyon 25–4–12, Nutricote 18–6–8 (270–30 lb/yd3), and Nutricote 18–6–8 (270–20 lb/yd3) produced high-quality plants for most of the species evaluated. The control and Nutri-Pak 18–6–12 treatments resulted in relatively poor-quality plants across the board. The effects of irrigation techniques on leachate analysis are being completed.
Promoting the Residential Habitat Garden through Education
Authors: Johnson James
Published: February 2019

As the need to design residential landscapes in an environmentally sensitive manner becomes more apparent, the demand for educational materials and activities that promote the habitat garden is growing. In response to this need, an educational plan, ranging from the publication of a booklet to the implementation of a demonstration garden, has been undertaken. The booklet should serve both the homeowner and the professional designer interested in wildlife-sensitive designs. Horticultural faculty and students are being organized to implement one of my designs on the Clemson Univ. campus to demonstrate the habitat garden concepts found in the booklet. Working with local homeowners by designing and having their yards certified by the National Wildlife Federation as “Backyard Wildlife Habitats” has also served to promote the habitat garden. I am also working with the Dept. of Horticulture and senior citizen volunteers to raise money to build a demonstration garden in the South Carolina State Botanical Garden. The incorporation of written materials, designs, certifications, and demonstration gardens into an educational package has resulted in a community effort to promote the habitat garden.
Growth and Economic Assessments of Kenaf Core as the Major Component in Greenhouse Potting Media
Authors: Williams R. Dudley , Baldwin Brian S. , Reichert Nancy A.
Published: February 2019

Two types of ground kenaf core (fresh and aged) were used in concentrations from 70% to 100% (v/v) in combination with peat for use as greenhouse potting media, and were compared to two commercial mixes in completely randomized-block designs. Greenhouse crops of Boston fern (Nephrolepis), Impatiens, and pansies (Viola) were grown in the different mixes. Irrigation was conducted regularly, based primarily on the average need of all the plants. Kenaf-based media did not retain water as well as the commercial mixes; consequently, impatiens and pansies displayed slower growth rates. However, no differences were noted for fern growth in 70% kenaf compared to commercial mixes. A second study on plants that were grouped by media type and watered as needed provided different results. Ferns grew equally well in all media, but Impatiens grew best in 70% fresh kenaf. Kenaf-based media were less costly than the commercial mixes, and the cost decreased steadily as the kenaf proportion increased. The lower cost of kenaf, coupled with the decreasing availability of peat, should make kenaf-based media an attractive alternative to conventional greenhouse potting media.
Response of Wetland Taro Yield and Weeds to Preplant Establishment of Azolla in Hawaii
Authors: DeFrank Joseph
Published: February 2019

Azolla (Azolla filiculoides) is a floating fern that maintains a symbiotic relationship with an N-fixing blue-green algae. In many parts of Asia, azolla is used as a green manure in flooded rice cultivation. Taro (Colocasia esculenta) grown under flooded conditions is used to produce a traditional Hawaiian staple, poi. Azolla has been present in Hawaii for many years, but is not used in a controlled way for either nutrient augmentation of production sites or weed suppression. In this experiment, azolla was removed from a stream on the island of Kauai and multiplied in a nursery pond. Phosphoric acid was added to the nursery pond as a nutrient (P = 5 ppm) at 5-day intervals to accelerate azolla growth. Azolla was moved from the nursery pond and added to taro production plots at a seeding rate of 488 kg·m–2. Phosphoric acid was used in production plots to hasten coverage of the water surface by azolla. Ten days after azolla inoculation, production plots were covered and taro seed pieces were planted. Weed dry weights from conventional and azolla covered plots were recorded 91 days after taro planting. Taro corms were harvested 315 days after planting. Weed dry weight in azolla plots was 86% less than conventional plots. Azolla delayed taro maturity, causing a 41% reduction in marketable corm yield.
The Effect of Bud Thinning on Yield Compensation in `Kotata' and `Marion' Trailing Blackberry
Authors: Mann Juliet , Strik Bernadine C.
Published: February 2019

Mature `Kotata' and `Marion' trailing blackberry plants were studied in 1994. In `Kotata', canes were subjected to 0%, 25%, 50%, 75%, or 100% primary bud removal in Feb. 1994. In `Marion' 0, 55, or 100 primary buds were removed per dm2 from fruiting sections (panels). Primary bud removal did not subsequently affect yield per cane or per dm2 in either cultivar. Yield compensation occurred through production of secondary laterals, which were as fruitful as primary laterals.
The Effect of a Competitor Species on the Seedling Development of Lythrum salicaria
Authors: Snider Anna , Nimani Visar , McEntee Kerry , Percival Scott
Published: February 2019

Purple loosestrife (Lythrum salicaria) is a plant that was originally introduced to the United States as an ornamental, but was soon found to be invasive in wetland habitats. Lythrum reduces plant and wildlife diversity in these areas and causes the extinction of rare species. Our research was conducted to determine if another species planted along with Lythrum would act as a competitor and reduce the invasive characteristics of the plant. We also compared this with its invasiveness in different types of media (peatmoss and sand) to determine if its ability to take over was related to the media in which it was growing. The competitor species we chose was cordgrass (Spartina pectinata) because it is a typical grass native to wetlands. We varied the planting times of the Lythrum and Spartina in different pots and recorded germination rates and the final dry weights of both species. We found significant differences among the plants at each planting time and between the plants in the peatmoss and sand.
Agrobacterium rhizogenes Influences in Vitro Morphogenesis in Stem Segments of Woody Plants
Authors: Pope Torin O. , Beyl Caula A.
Published: February 2019

Agrobacterium rhizogenes is a valuable new tool for inducing adventitious roots in difficult-to-root ornamentals To evaluate species and strain interactions, three ornamental species were chosen: Hydrangea quercifolia, Pyrus calleryana, and Photinia × fraserii. Terminal shoots (2.5 cm long) were collected at bud swelling and then immersed in bleach (20% v/v) for 10 min with stirring. They were rinsed three times in sterile distilled water and cultured individually in test tubes containing 15 ml of Murashige and Skoog medium. After 3 weeks, the uncontaminated shoots were divided into five groups: four strains of A. rhizogenes and a control. There was a significant effect of strain and species in the production of callus and organs from the shoot tips. The presence of strain by host interaction was observed In the morphogenic response of explants.
Can Designers Work Horticulture Education into the Process of Public Horticulture?
Authors: Badertscher Kerrie B.
Published: February 2019

A 5-acre neighborhood park in Longmont, Colo., was designed for a senior design class. A series of town meetings coordinated with special interest groups was used to develop the design. The first goal of the town meetings was to provide the community with a sense of ownership of the park. Park requirements included a protected wetland, recreational needs, and circulation to other parks and open space. The design integrated facilities placement, recreational equipment, bird viewing areas, a wetland interpretive walk, and ease of maintenance and accessibility. Input from the town meetings led to several design manipulations. Native vegetation was reclaimed with native forbs and grasses. The use of native plantings integrated into the design will be reviewed as will the input from the several groups. This will focus on the educational process and impact on the final document without a loss of integrity of the design.
Genotype and Fertilization Effects on Trypsin Inhibitor Activity in Sweetpotato
Authors: Zhang Dapeng , Collins Wanda W. , Andrade Maria
Published: February 2019

Sweetpotato [Ipomoea batatas (L.) Lam.] is intensively used as an animal feed in many developing countries. Information about trypsin inhibitor activity (TIA), an antinutritional component in this crop, will be useful for breeding sweetpotato as animal feed. Nine sweetpotato lines were grown at two locations and fertilized or nonfertilized conditions at each location. Samples were analyzed for TIA using a substrate-specific colorimetric method. Soybean [Glycine max (L.) Merr.] seeds were used to compare the levels of TIA in sweetpotato and soybean. Activity in roots ranged from 29.5 to 55.0 units in the nine lines. The mean TIA in roots was 40.7 units averaged over lines and environments, which was ≈28% of the mean for the five soybean cultivars. Activity in sweetpotato vines was only ≈14.6% of that in the roots, and TIA in fertilized plots was 150% and 67% higher than that in nonfertilized plots in the two locations, respectively. There was a small but significant positive correlation between TIA and crude protein in roots. These results suggested that TIA in sweetpotato storage roots may be high enough to have a substantial nutritional impact on animals, whereas TIA in vines is very low and should be of less nutritional concern.