Papers by Linda Chalker-Scott
Physiologia Plantarum, Nov 1, 1994
The change in the cold hardiness of Rhododendron (cv. English Roseum) following chronic exposure ... more The change in the cold hardiness of Rhododendron (cv. English Roseum) following chronic exposure to ultraviolet‐B (UV‐B) radiation (280–320 nm) was studied. Leaf disks removed from UV‐B‐exposed plants exbibited a greater tolerance to freezing temperatures than plants that received no UV‐B exposure. Visual browning and percent phenolic leakage indicated that UV‐B‐exposed leaf disks were killed al ‐11°C. while control disks were killed at ‐8°C. Ultraviolet‐induced production of phenolic compounds may be involved in increasing cold hardiness of Rhododendron leaf tissues.
Gardeners have heard that black walnut trees (Juglans nigra) contain a toxic chemical called jugl... more Gardeners have heard that black walnut trees (Juglans nigra) contain a toxic chemical called juglone that will kill any other plants growing nearby. This phenomenon is called allelopathy, and, in recent years, many other possible allelopathic chemicals have been identified. This publication will review the current research into black walnut allelopathy and discuss the practical significance of gardening in the presence of black walnut trees
Journal of the NACAA, Dec 3, 2017
Marine Biology, Oct 1, 1995
ABSTRACT The marine harpacticoid copepod, Tigriopus californicus (Baker), is a successful coloniz... more ABSTRACT The marine harpacticoid copepod, Tigriopus californicus (Baker), is a successful colonizer of supralittoral splash pools from Torch Bay, Alaska, to Baja California, Mexico. As these pools are subject to abundant amounts of direct solar radiation, it was of interest to determine the sensitivity of T. californicus to ultraviolet-B (UV-B, 290 to 320 nm) radiation. During 1980, copepods were raised under diurnal conditions in the laboratory and fed a mixture of unicellular algae and bacteria. Larval and adult stages were irradiated for 0 to 26 h on a rotating turntable under enhanced ultraviolet radiation. Following irradiation, the copepods were maintained in the culture area and checked daily for survival. All life stages of T. californicus tolerated enhanced UV-B radiation irrespective of exposure period; in contrast, survival of an irradiated planktonic copepod, Acartia clausii (Giesbrecht), was significantly lower. Additionally, there appeared to be asex ratio shift in adults that developed from the youngest naupliar stages (N1/N2) of T. californicus that were irradiated. Extraction and tentative identification of the pigment(s) responsible for the bright orange color of the carapace of T. californicus were performed. These pigments may function to absorb UV radiation and protect internal structures from photochemically induced damage.
Residential gardeners often collect rainwater to supplement summer irrigation. They may also use ... more Residential gardeners often collect rainwater to supplement summer irrigation. They may also use rainwater as an unchlorinated water source for aquatic plants and animals. However, rooftop runoff can be contaminated with chemical and biological pollutants. This publication will examine the research behind residential rain barrel water safety in North America over the last 20 years. It will also provide science-based suggestions for using rain barrel water in ways that protect people, pets, and the environment
Epsom salt is a popular soil amendment for home gardeners with anecdotally-reported value as a fe... more Epsom salt is a popular soil amendment for home gardeners with anecdotally-reported value as a fertilizer and pesticide. However, it is not registered as a pesticide, nor should it ever be used as a pesticide. This publication will review the scientific evidence behind the use of Epsom salt in home gardens and provide readers with a set of guidelines designed to improve soil nutrient conditions and promote plant health
Most popular website for free PDF. Platform is a high quality resource for free eBooks books.Give... more Most popular website for free PDF. Platform is a high quality resource for free eBooks books.Give books away. Get books you want. You have the option to browse by most popular titles, recent reviews, authors, titles, genres, languages and more.Open library is a volunteer effort to create and share e-books online. No registration or fee is required, and books are available in ePub, Kindle, HTML and simple text formats.The deeharga.com is home to thousands of free audiobooks, including classics and out-of-print books. No registration or fee is required, and books are available in ePub, Kindle, HTML and simple text formats.
Marine Biology, 1995
ABSTRACT The marine harpacticoid copepod, Tigriopus californicus (Baker), is a successful coloniz... more ABSTRACT The marine harpacticoid copepod, Tigriopus californicus (Baker), is a successful colonizer of supralittoral splash pools from Torch Bay, Alaska, to Baja California, Mexico. As these pools are subject to abundant amounts of direct solar radiation, it was of interest to determine the sensitivity of T. californicus to ultraviolet-B (UV-B, 290 to 320 nm) radiation. During 1980, copepods were raised under diurnal conditions in the laboratory and fed a mixture of unicellular algae and bacteria. Larval and adult stages were irradiated for 0 to 26 h on a rotating turntable under enhanced ultraviolet radiation. Following irradiation, the copepods were maintained in the culture area and checked daily for survival. All life stages of T. californicus tolerated enhanced UV-B radiation irrespective of exposure period; in contrast, survival of an irradiated planktonic copepod, Acartia clausii (Giesbrecht), was significantly lower. Additionally, there appeared to be asex ratio shift in adults that developed from the youngest naupliar stages (N1/N2) of T. californicus that were irradiated. Extraction and tentative identification of the pigment(s) responsible for the bright orange color of the carapace of T. californicus were performed. These pigments may function to absorb UV radiation and protect internal structures from photochemically induced damage.
Journal of the NACAA, Dec 2, 2018
Home gardeners and landscape professionals are a rapidly growing audience for extension educators... more Home gardeners and landscape professionals are a rapidly growing audience for extension educators as they seek science-based information to support their activities. However, many are not familiar with current research and cannot assess whether the information they find in print, on the internet, or through social media is accurate. In addition, some products and practices are meant for agricultural production, not for maintaining home gardens and landscapes. The combination of misinformation and misapplied information means that this audience risks damaging their plants and soils through overuse of fertilizers, misuse of pesticides, and poor management practices. The field of urban horticulture, including arboriculture, is expanding with new insights about plants and soils in residential and public landscapes. However, there are few Extension educators who have an academic background in environmental horticulture and may be as confused as the public about what constitutes sound, science-based recommendations. The authors of this article are state Cooperative Extension educators and researchers with many years of experience in translating science for use by home gardeners and landscape professionals. Our goal is to assist other Extension educators by providing reliable information for them to share with the gardening and landscaping public. The purposes of this literature review article are: • to identify some common beliefs homeowners and landscape professionals have about managing landscape plants and soils; • to provide a brief, science-based explanation on why these beliefs are not accurate; • to provide links to published, peer-reviewed information that supports the explanation and can be distributed to clientele; and • to suggest strategies based on current and relevant applied plant and soil sciences for managed landscapes. Myth #1: "Native trees and shrubs are superior to introduced species for wildlife habitat" Many landscapes are overrun by exotic species deliberately introduced for ornamental or revegetation purposes. Research documents how exotic, invasive species can outcompete native plants and decrease the ecological and aesthetic value of landscapes (Figure 1; Reichard and White 2001). As a result, homeowner associations, communities and entire cities have adopted "native only" planting specifications. Such policies have the unfortunate side effect of eliminating any exotic, noninvasive species from planting consideration. The rationale for native-only policies has centered on the belief that native plants have coevolved with native animals and are uniquely suited to providing food and shelter for them. What believers fail to consider is that urbanized landscapes are no longer natural (Figure 2).
Journal of Environmental Horticulture
Despite global concerns regarding climate change, one thing remains constant: homeowners want gar... more Despite global concerns regarding climate change, one thing remains constant: homeowners want gardens and landscapes that serve them functionally and aesthetically. The strong affinity homeowners have for their land can lead to excessive use of water and fertilizer. This literature review explores the relationships between homeowners and their residential landscapes and the efforts that can be made to address misuse and overuse of resources. Governmental organizations should work together with community groups, nursery and landscape associations, and university Extension faculty to understand homeowner desires and behaviors before instituting policies regarding resource use that are unpopular, resented, and ignored. Networking between the nursery industry and university Extension faculty and Master Gardener volunteers can provide educational opportunities for homeowners to understand and implement more sustainable landscape practices as well as showcasing ornamental landscape plants...
Horticultural oils are manufactured from either petroleum or vegetable oils, to be used as a pest... more Horticultural oils are manufactured from either petroleum or vegetable oils, to be used as a pesticide on plants. Regardless of the source, these oils kill eggs, larvae, and nymphs of insects and mites by smothering them.This publication explains the types of oils, how they can be used as pesticides, and what drawbacks there are to their use
Dust mulching is a soil-water conservation practice recommended by some popular gardening books a... more Dust mulching is a soil-water conservation practice recommended by some popular gardening books and websites for home gardeners. While dust mulching may be an effective practice for dryland agricultural production, there is little scientific support for its use in home gardens. This publication reviews the science behind dust mulching and will guide home gardeners to more appropriate mulch materials for their gardens and landscapes.
Pullman, Washington : Washington State University Extension, Sep 1, 2019
Processed seaweeds, especially kelps, are heavily marketed to gardeners as biostimulants, fertili... more Processed seaweeds, especially kelps, are heavily marketed to gardeners as biostimulants, fertilizers, soil conditioners, disease suppressants, and environmental stress reducers. This publication reviews the published research on seaweed products regarding their effectiveness in home gardens and landscapes. It also discusses the ecological and environmental consequences of using wild-harvested kelps
Cornmeal and corn gluten meal, both products from corn milling, are readily available to home gar... more Cornmeal and corn gluten meal, both products from corn milling, are readily available to home gardeners. This fact sheet reviews the horticultural science behind each of these products and explains whether they have a legal and practical use in home gardens and landscapes. Alternative strategies are suggested for situations where neither product should be applied
All gardeners in Washington State are aware of seasonal changes in leaf color. Many deciduous lea... more All gardeners in Washington State are aware of seasonal changes in leaf color. Many deciduous leaves turn some shade of red before they fall during the autumn months. The red coloration is due to the production of leaf pigments called anthocyanins, which are also found in red, blue, and purple flowers and fruits. But leaves can also turn red for reasons unrelated to autumn color development. This fact sheet will outline those reasons and explain when red leaves indicate the need for corrective action by gardener
The objective of the study was to determine whether Washington State Department of Transportation... more The objective of the study was to determine whether Washington State Department of Transportation's (WSDOT's) winter use of road anti-icer compounds on Highway 2 in Chelan County, Washington, is having an impact on the federally endangered plant species Hackelia venusta. A controlled study was performed in the outdoor facilities at the Center for Urban Horticulture-University of Washington. This study evaluated two road anti-icer formulae available to WSDOT in the 2000-2002 winter seasons by testing the effects of different anti-icer dilutions on plant and soil parameters. Since it was not feasible to use H. venusta in a controlled study during the time of implementation, two other species were used. One species, Mertensia platyphylla, is a phylogenetic relative and the other, Eriophyllym lanatum, is a non-related ecosystem associate. From the analysis, the authors were able to conclude that both road anti-icers begin to have detrimental effects by causing a decrease in abov...
Uploads
Papers by Linda Chalker-Scott