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Multifunctionality In U.S. Rice Production: A Logit Analysis In Farmers Participation, Juan Tur Cardona

Graduate Theses and Dissertations

Multifunctional agriculture is particularly fundamental to some working lands conservation policies and programs, such as the Environmental Quality Incentive Program (EQIP), Conservation Security Program (CSP) and Wildlife Habitat Incentive Program (WHIP). Farmers can also be engaged in providing recreational and agri-tourism services such as hunting, fishing, bird-watching, farm tours, petting zoos and hospitality services. Using the Agricultural Resource Management Survey (ARMS) we analyze factors associated with participation in conservation, recreation and agri-tourism activities as a function of farm structure, farm financial measures, production practices, and socio-demographic characteristics of the farm operator. To estimate the functional relationships we estimate a binary …

The Ecological Roles Of Podostemum Ceratophyllum And Cladophora In The Habitat And Dietary Preferences Of The Riverine Caddisfly Hydropsyche Simulans, Brenna Tinsley

Mahurin Honors College Capstone Experience/Thesis Projects

The net-spinning caddisfly Hydropsyche simulans can be a common inhabitant of shallow reaches in riverine systems, and is easily the most common hydropsychid in the upper Green River, Kentucky. This study was performed in summer 2011 and focused on two main questions: 1. Do the larvae of the riverine caddisflies H. simulans and Cheumatopsyche preferentially inhabit dense patches of P. ceratophyllum compared to bare substrates in the upper Green River?, and 2. Do larvae of H. simulans and Cheumatopsyche consume the filamentous alga Cladophora during the annual late summer algal bloom in the upper Green River? Densities of both hydropsychid …

The Effect Of Phosphite On Mycorrhiza Formation In American Chestnut (Castanea Dentata), Matthew T. Perkins

Honors Theses

One of the primary hindrances to Castanea dentata restoration in the Southeast is the root rot disease caused by the fungus-like microorganism Phytophthora cinnamomi. Root rot can be combated by the application of mono- and di-potassium salts of phosphorous acid, which are marketed as phosphite fungicides. Despite its value in preventing infection by P. cinnamomi it is also thought that phosphite may impede root colonization by beneficial, ectomycorrhizal fungi. I hypothesized that plants given a routine application of phosphite will display fewer mycorrhizas in the root tips than those plants that were not treated with potassium phosphite. Therefore I attempted …

Ecology And Integrated Pest Management Of Western Bean Cutworm Striacosta Albicosta (Smith) (Lepidoptera: Noctuidae) In Field Corn, Silvana L. Vieira De Paula Moraes

Department of Entomology: Dissertations, Theses, and Student Research

Western bean cutworm, Striacosta albicosta (Smith) (Lepidoptera: Noctuidae), is a native pest of dry beans (Phaseolus vulgaris L.) and corn (Zea mays L.), and historically distributed in the western United States. The insect’s recent expansion eastward is documented since 1999. The species is univoltine, the adults typically emerge in the middle of July, lay eggs on corn leaves, and the larvae feed on different corn tissues. In the fourth instar, larvae start colonization of the ear where they feed on kernels. There is a narrow window for management and early detection of the pest in the field is …

Nest And Brood Site Selection And Survival Of Greater Prairie-Chickens In The Eastern Sandhills Of Nebraska, Lars Anderson

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Greater prairie-chickens (Tympanuchus cupido pinnata) are a grassland bird species of conservation concern. Although greater prairie-chickens have declined over much of their range, the Nebraska Sandhills has the largest population in North America. However, the responses of nest and brood site selection and survival to vegetation characteristics are unknown. I studied prairie-chickens on private rangelands in Rock and Brown Counties from 2009-2011. I fitted 139 females with radio collars to locate nest and brood sites and to determine nest and brood survival rates. Females were trapped on leks during the breeding season and I monitored them throughout the …

Assessment Of Oxidative Stress Gene Expression In Brassicaceae Plant Species Using A Real-Time Pcr Method, Florestella Ruiz

Theses and Dissertations - UTB/UTPA

Many plant species in the Brassicaceae plant family possess the ability to accumulate heavy metals. One challenge in using these hyperaccumulator plants for phytoremediation is that they are slow growing and often have a low biomass. This is a limitation should they be utilized for phytoremediation. However, the mechanisms by which hyperaccumulators tolerate heavy metals are of interest as these characteristics can be engineered into a plant species that is more suited for use in phytoremediation. Therefore, modification of oxidative stress response (OSR) gene expression in Brassicaceae species has become of great interest. Oxidative stress gene induction in both non-accumulator …

Insecticidal Control Of Bemisia Tabaci (Hemiptera: Aleyrodidae) Transmitting Carlavirus On Soybeans And Detection Of The Virus In Alternate Hosts, Difabachew K. Belay, Randy M. Huckaba, Axel M. Ramirez, Jose C. V. Rodrigues, John E. Foster

Department of Entomology: Faculty Publications

A Carlavirus transmitted by Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is an important disease of soybean nurseries in Puerto Rico causing substantial germplasm losses. Insecticide bioassay experiments were conducted at Dow AgroSciences (DAS) Research Station, Santa Isabel, Puerto Rico, either by spraying insecticides on B. tabaci infested soybean leaves or introducing B. tabaci adults onto insecticide-sprayed soybean leaves. Moreover, host plants were surveyed to detect the virus in overwintering hosts that serve as a source of inoculums. The direct spray experiment showed that Nuprid 2F (Imidacloprid), Capture 2 EC (Bifenthrin), Thionex (Endosulfan), Lannate LV (Methomyl), and Dimethoate gave good level ( …

Host Plant Use By Competing Acacia-Ants: Mutualists Monopolize While Parasites Share Hosts, Stefanie Kautz, Daniel J. Ballhorn, Johannes Kroiss, Steffen U. Pauls, Corrie S. Moreau, Sascha Eilmus, Erhard Strohm, Martin Heil

Biology Faculty Publications and Presentations

Protective ant-plant mutualisms that are exploited by non-defending parasitic ants represent prominent model systems for ecology and evolutionary biology. The mutualist Pseudomyrmex ferrugineus is an obligate plant-ant and fully depends on acacias for nesting space and food. The parasite Pseudomyrmex gracilis facultatively nests on acacias and uses host-derived food rewards but also external food sources. Integrative analyses of genetic microsatellite data, cuticular hydrocarbons and behavioral assays showed that an individual acacia might be inhabited by the workers of several P. gracilis queens, whereas one P. ferrugineus colony monopolizes one or more host trees. Despite these differences in social organization, neither …

Enabling Marker-Assisted Breeding (Mab) For Blush In Peach [Prunus Persica (L.) Batsch], Terrence Frett

All Theses

ABSTRACT
Phenotyping is a crucial component for using DNA-based tools in gene discovery and marker development. Phenotypic and genotypic data are essential for linking genetic variation with biological function, thus documenting gene function. However, phenotypic data gathering is not keeping pace with the immensely increasing amount of available genomic information, brought forth by current Next Generation Sequencing technologies. Standardized phenotyping protocols for peach [Prunus persica (L.) Batsch] have been developed for 6 productivity traits (on the tree) and 16 fruit quality traits. Documentation of fruit quality phenotypes has been performed applying developed standardized phenotyping protocol in two seasons, at nine …

Understanding The Importance Of The Zinc Binding Domain In Cesa Protein Interaction: Some Assembly Required, Alfred Schupp Iii

Senior Honors Projects

Understanding the Importance of the zinc binding domain in the cellulose synthase complex: Some Assembly Required

Alfred Schupp

Sponsor: Alison Roberts, Biological Sciences

Cellulose microfibrils are vital components of the cell wall. A microfibril is made up of multiple strands of glucose chains, and these cellulose microfibrils are produced by protein complexes in the plasma membrane called cellulose synthase complexes, or CSCs for short. Each complex is made up of 36 subunits called Cellulose Synthase proteins, or CESAs. Each CESA produces a glucose polymer made from beta-1,4 glucan linkages. It is known that CESA proteins aggregate to form CSCs, and …

Investigating Three Decades Of Vegetation Change In A Mojave Desert Mountain Range, Chris Lee Roberts

UNLV Theses, Dissertations, Professional Papers, and Capstones

This project is a vegetation change study spanning 29 years in the Newberry Mountains of Southern Nevada. Long term monitoring data are crucial for understanding the effects of climate change on vegetation dynamics. Successful management intervention in vegetation change will require identification of early indicator plant species and their responses to climatic cues. This project is one of the oldest comparisons of resurveyed Mojave vegetation community plots with repeatable methodology and the longest survey interval reported for the southeastern Mojave Desert. 103 plots were relocated and resurveyed based on data methods in Jim Holland's thesis titled "A Vegetative Analysis of …

The Foliar Nematode Aphelenchoides Fragariae: Studies On Facultative Feeding And Desiccation Tolerance, Zhen Fu

All Dissertations

The foliar nematode Aphelenchoides fragariae is an economically important and frequent pest of ornamental crops. In nurseries and landscapes in the United States, foliar nematodes can be a serious problem affecting hostas (Hosta spp.), a common perennial ornamental plant that thrives in shady environments. Fundamental research on the biology and ecology of this nematode provides the basis for development of sound management strategies. The general objective of this dissertation was to study two behaviors that make foliar nematodes very successful as plant pests: desiccation tolerance and alternative feeding on fungi (or facultative feeding on the plant). To study the molecular …

Biology, Histopathology, And Improvements In Axenic Culture Of Labyrinthula Terrestris, Causal Agent Of Rapid Blight Of Cool-Season Turfgrasses, Kirthi Kiran Yadagiri

All Dissertations

Rapid blight is a disease of cool-season turfgrasses caused by Labyrinthula terrestris. Disease symptoms include water-soaked lesions, yellowing and browning of foliage, and coalescing patches of dead turf. L. terrestris belongs to a group of marine microorganisms in the kingdom Chromista (also known as Stramenopila). Morphological characteristics of Labyrinthula spp. include spindle-shaped vegetative cells that move in an ectoplasmic network. The biology and pathology of L. terrestris is not clearly understood; therefore, the ultrastructure, life cycle, and histopathology of L. terrestris were investigated. In addition, improvements in axenic culture and long-term storage methods were made to better culture L. terrestris. …

Early Season Population Dynamics And Residual Insecticide Effects On Bird Cherry-Oat Aphid, Rhopalosiphum Padi In Arkansas Winter Wheat, Beven Mcwilliams

Graduate Theses and Dissertations

Bird cherry-oat aphid is a common pest of Arkansas winter wheat. This aphid vectors barley yellow dwarf virus which may cause extensive crop damage and yield loss when wheat is infested by virulent aphids in the fall. Some suggest this damage may be avoided using insecticide seed treatments if growers are unable to delay planting, as is recommended. Field population dynamics of bird cherry-oat aphid during fall 2009 and 2010 was assessed through random sampling of whole plants and pan trapping methods to evaluate aphid immigration. The field plots were divided into four subplots treated with a systemic insecticide seed …

Distribution And Control Of Herbicide-Resistant Italian Ryegrass (Lolium Perenne L. Ssp. Multiflorum Lam. Husnot) In Arkansas, James Walker Dickson

Graduate Theses and Dissertations

Italian ryegrass populations have evolved resistance to herbicides that producers rely on for weed control both in wheat and burn-down. The objectives of this research were to: test populations of Italian ryegrass from across Arkansas for resistance to glyphosate, diclofop, pinoxaden, and pyroxsulam; determine if there were any differences in control of 12 glyphosate-resistant populations in relation to glyphosate rate or application timing; determine the level of glyphosate resistance in one selected population versus a susceptible standard and a previously discovered glyphosate-resistant population; and determine the best options for controlling Italian ryegrass prior to planting crops. A total of 215 …

Herbicide Resistance Mechanism(S) In Italian Ryegrass (Lolium Perenne Ssp. Multiflorum) Populations In The Southern United States, Reiofeli Algodon Salas

Graduate Theses and Dissertations

Italian ryegrass is a principal weed problem in wheat production fields in the Southern US. Resistance to herbicides diclofop, mesosulfuron, and pinoxaden among ryegrass populations has been reported. Glyphosate-resistant Italian ryegrass populations were identified in Desha County, Arkansas. This research aimed to 1) determine resistance patterns to ACCase (diclofop and pinoxaden) and ALS (imazamox, mesosulfuron, and pyroxsulam) herbicides among Italian ryegrass populations from the southern US; 2) determine if cytochrome P450-mediated enhanced herbicide metabolism contributed to resistance; and 3) elucidate the resistance mechanism to glyphosate in four Arkansas populations (Des03, Des05, Des14, and D8). For objective 1, 30 accessions from …

Cotton Response To High Temperature Stress During Reproductive Development, Justin B. Phillips

Graduate Theses and Dissertations

Temperature is a primary controller of the rate of plant growth, developmental events, and fruit maturation. Increased temperatures from global climate change are projected to cause substantial losses in crop productivity by the end of the twenty-first century. Elevated temperatures affect all stages of cotton development, but the crop seems to be particularly sensitive to adverse temperatures during reproductive development. In Arkansas, temperature stress is considered to be one of the main factors affecting cotton yield. Environmental stress during floral development is a major reason for the disparity between actual and potential yields. Field and growth chamber studies were conducted …

Determining Compost Carryover For Optimal Use In An Organic Corn Squash Rotation, Davey J.R. Olsen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In 2008–2011 a graduate project was undertaken by Davey Olsen under the supervision of Utah State University (USU) Plant, Soils and Climate professors, Drs. Jennifer Reeve, Dan Drost, and Astrid Jacobson. The project investigated a new way of measuring the benefits of applying compost to organically certified horticultural crops. In particular, the carryover of these benefits in the three years following a one-time application was studied. A field trial at the USU Organic Farm modeled the carryover of nitrogen and phosphorus in a corn and squash rotation, while laboratory analysis investigated aspects of nitrogen availability and compost decomposition over time. …

Root-Knot Nematodes In Golf Course Greens Of The Western United States, Claudia Nischwitz

All Current Publications

No abstract provided.

Edaphic Adaptation Maintains The Coexistence Of Two Cryptic Species On Serpentine Soils, Jenn M. Yost, Teri Barry, Kathleen M. Kay, Nishanta Rajakaruna

Biological Sciences

• Premise of the study: Divergent edaphic adaptation can contribute to reproductive isolation and coexistence between closely related species, yet we know little about how small-scale continuous edaphic gradients contribute to this phenomenon. We investigated edaphic adaptation between two cryptic species of California wildflower, Lasthenia californica and L. gracilis (Asteraceae), which grow in close parapatry on serpentine soil.

• Methods: We reciprocally transplanted both species into the center of each species’ habitat and the transition zone between species. We quantified multiple components of fitness and used aster models to predict fitness based on environmental variables. We sampled soil across the …

Herbaceous 2012 (April 21), Amy L. Myers, Julia I. Chapman, Ryan W. Mcewan

Data Files: Drew Woods Permanent Plots

Herbaceous vegetation data collected in 2012 at Drew Woods State Nature Preserve in Darke County, OH. Data key is provided in a supplemental file.

Traversing Swanton Road, 7th Ed., James A. West

Academic, Government & Associated Organizational Research Resources

Situated at the northwest end of Santa Cruz County and occupying circa 30 square miles of sharply contrasted terrain, the Scott Creek Watershed concentrates within its geomorphological boundaries, at least 10-12% of California's flora, both native and introduced. Paradoxically, the use/abuse that the watershed has sustained over the past 140+ years, has not necessarily diminished the biodiversity and perhaps parallels the naturally disruptive but biologically energizing processes (fire, flooding, landslides and erosion), which have also been historically documented for the area for +60 years. This is an early edition of an extensive document by James A. West. Please visit the …

Maple Syrup: St. John’S Sweetest Springtime Tradition, Stephen G. Saupe

Biology Faculty Publications

St. John’s is the home of one of Minnesota’s oldest maple syrup operations. The monks began making syrup in 1942 and have continued roughly every other spring until the present. Currently, the operation is jointly run by the Abbey and St. John’s Arboretum and it is one of the few maple syrup operations associated with a Minnesota college or university. The process by which maple syrup is made at St. John’s differs little from the procedures begun more than 60 years ago. In spring, sugar maple trees are tapped, sap is collected, and then it is boiled in the sugar …

Seed Mucilage Improves Seedling Emergence Of A Sand Desert Shrub, Xuejun Yang, Carol C. Baskin, Jerry M. Baskin, Guangzheng Liu, Zhenying Huang

Biology Faculty Publications

The success of seedling establishment of desert plants is determined by seedling emergence response to an unpredictable precipitation regime. Sand burial is a crucial and frequent environmental stress that impacts seedling establishment on sand dunes. However, little is known about the ecological role of seed mucilage in seedling emergence in arid sandy environments. We hypothesized that seed mucilage enhances seedling emergence in a low precipitation regime and under conditions of sand burial. In a greenhouse experiment, two types of Artemisia sphaerocephala achenes (intact and demucilaged) were exposed to different combinations of burial depth (0, 5, 10, 20, 40 and 60 …

Herbaceous 2012 (April 9), Amy L. Myers, Julia I. Chapman, Ryan W. Mcewan

Data Files: Drew Woods Permanent Plots

Herbaceous vegetation data collected in 2012 at Drew Woods State Nature Preserve in Darke County, OH. Data key is provided in a supplemental file.

Diversification Of Organic Cropping Systems With Cover Crop Mixtures: Influence On Weed Communities, Soil Microbial Community Structure, Soil Moisture And Nitrogen, And Crop Yield, Samuel E. Wortman

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Organic grain cropping systems typically depend on intensive mechanical cultivation for weed control and manure or compost applications to meet plant nutrient demands. However, cover crops may contribute to weed suppression and soil fertility, potentially increasing crop yield and sustainability of the system. The utility of individual cover crop species have been well documented, but the agronomic benefits of diverse cover crop mixtures have received less attention. Cover crop mixtures are an appealing option for farmers, as increasing species diversity has been shown to increase resource-use efficiency, stability, resiliency, and productivity of plant communities. Despite the growing interest in cover …

High-Tech Tactic May Newly Expose Stealthy Salmonella, Marcia Wood, Bosoon Park

Agricultural Research Magazine

At laboratories of the future, even the smallest quantity of Salmonella bacteria may be easily detected with a technology known as “SERS,” short for “surface-enhanced Raman scattering.”

Agricultural engineer Bosoon Park, in the Agricultural Research Service’s Quality and Safety Assessment Research Unit in Athens, Georgia, is leading exploratory studies of this analytical technique’s potential for quick, easy, and reliable detection of Salmonella and other foodborne pathogens.

According to the U.S. Centers for Disease Control and Prevention, Salmonella causes more than 1 million cases of illness in this country every year.

Protein Biomarkers: Identify Disease-Carrying Aphids, Dennis O’Brien

Agricultural Research Magazine

Aphids can transmit viruses that cause crop diseases and reduce the quality and quantity of fresh foods. Spraying insecticides can control aphids and reduce the spread of viruses, but spraying is expensive and can harm the environment. Additionally, not all aphids transmit viruses. So a key question for growers is knowing when and what to spray to control viral diseases.

Agricultural Research Service scientists Michelle Cilia and Stewart Gray, in the Biological Integrated Pest Management Unit at the Robert W. Holley Center for Agriculture and Health in Ithaca, New York, have found a way to distinguish aphids that spread viruses …

Metagenomics Offers Insight Into Poultry Diseases, Sandra Avant

Agricultural Research Magazine

Less than 10 years ago, the world marveled at the completion of the human genome project, which involved traditional technology to identify all the genes in a single organism—the human. Today, a more powerful technology is being used to detect thousands of organisms in an entire community.

Unlike traditional gene sequencing, the new molecular technique—metagenomics— eliminates the need to cultivate and isolate individual microbial species. Scientists can apply genomic analysis to mixed communities of microbes instead of to just one organism.

For example, researchers examining viral enteric (intestinal) diseases in poultry can take intestinal samples from different poultry flocks. The …

What's In Your Blood? The Ongoing Hunt For Metabolites, Marcia Wood, John W. Newman

Agricultural Research Magazine

At any given time, blood circulating through your body carries thousands of small molecules known as “metabolites.” Medical and nutrition researchers are eager to discover more about these compounds—amino acids, sugars, fats, and more—that are formed in and by our bodies.

Metabolites are of interest because the presence and concentrations of some of them can provide meaningful profiles, sometimes referred to as “metabolic signatures” or “fingerprints.”

In the future, for instance, yourmetabolic fingerprint—detected in a small sample of blood taken for your annual physical examination—might prove to be a reliable indicator of your health and a predictor of certain diseases. …