Digital Commons Network^™

Autism In Agricultural Education: A Case Study Of An Adolescent With Autism Spectrum Disorder And Their Parent On Career And Technical Education, Grace Miller

Theses and Dissertations--Community & Leadership Development

Autism spectrum disorder (ASD) is a unique and often misunderstood diagnosis. Little is known about the experiences of adolescents with ASD. As students with ASD graduate high school, many are under- and unemployed. Career and technical education (CTE) in U.S. schools is intended to prepare all students for careers post-secondary. Agricultural education is one of the predominate career clusters within CTE. This qualitative single case study sought to create a platform for both a student and their parent to share their experiences in agricultural education and CTE. Participants were an adolescent with ASD who had taken at least one year …

Assessing Endophyte Frequency Distributions And The Effect Of Epichloë Brachyelytri In The Chemotypic And Genotypic Diversity Of Brachyelytrum Erectum, Rachel Ann Sneed

Theses and Dissertations--Plant Pathology

Seed-transmissible epichloid fungal endophytes are best known for their roles as defensive mutualists in cool-season grasses. Historically, the discovery of fungal endophytes was driven by investigations of plant toxicity to livestock, followed by extensive study of their alkaloids and protection against insects and nematodes. Epichloae can produce four classes of alkaloids: ergot alkaloids, lolines (saturated aminopyrrolizidines), indole–diterpenes, and peramine. It is increasingly evident that these hereditary symbionts have much more diverse chemical profiles both in individual populations and between them. To this end, differences in chemotypic profiles of these symbionts may translate to different evolutionary and environmental advantages across plant …

Evaluation Of Winter Cereal Cover Crops Across Nitrogen Management Strategies In No-Till Corn Production, Robert Nalley

Theses and Dissertations--Plant and Soil Sciences

Rye (Secale cereale L.) is the most popular winter cereal cover crop utilized before corn, but wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) may provide a comparable value due to their similar fibrous root systems. Despite the benefits associated with winter cereal cover crops, drawbacks are possible for the subsequent corn crop. A field study was conducted with three site-years in Kentucky to measure the impact of the three winter cereals across nitrogen (N) management strategies. Wheat produced the most biomass compared with barley or rye cover crops. Wheat and rye needed approximately 100 more …

Indoor Pests And Human Health: Characterizing Contaminants And Improving Mitigation, Johnalyn Gordon

Theses and Dissertations--Entomology

Much of the United States population spends the majority of their time indoors and within the home. Not only are indoor arthropod pests an unsightly nuisance in our homes, but they can have serious impacts on human health, especially with chronic exposure. In addition to negative health impacts, costs associated with these medical impacts can be tremendous. For these reasons, it is critical to develop comprehensive strategies for pest reduction and mitigation of associated health impacts. The work outlined in this dissertation represent examination of the distribution of a hypothesized bed bug allergen within the indoor environment, identification of a …

Practical Challenges In Delivering Dsrna For Woody Plant Protection, Zachary Bragg

Theses and Dissertations--Entomology

Unprecedented weather events associated with climate change, coupled with extensive anthropogenic stresses, have reduced the effectiveness of traditional forest pest management approaches, which can no longer keep pace with invasive species overwhelming naïve landscapes and native pests experiencing eruptive and expansive outbreaks. Double-stranded RNA-(dsRNA) mediated gene silencing, a type of RNA interference (RNAi), has been coopted for use as a biopesticide against a multitude of agricultural and horticultural pests and could serve as a powerful tool for woody plant protection. While effective initiation of gene silencing and subsequent mortality have been demonstrated in multiple tree pests, effective and efficient methods …

Polymorphism And Plasticity In The Termite Caste System, Austin Merchant

Theses and Dissertations--Entomology

Developmental plasticity, manifested as a caste system, is integral to the success of eusocial insects because of the way in which it decouples the various tasks that a single, solitary organism would normally be responsible for, allowing individuals to specialize towards their given roles while keeping vulnerable members of the colony, such as those responsible for reproduction, safe from harm. Termites exhibit particularly complex caste systems that can be divided into three types of castes: workers perform manual labor, such as foraging and brood care; soldiers defend the nest; and reproductives lay eggs. Each of these castes, as well as …

Addressing The Trade-Offs Of Pest Protective Row Covers For Integrated Pest Management In Vegetable Production, Kathleen Fiske

Theses and Dissertations--Entomology

The success of many integrated pest management (IPM) strategies is limited by trade-offs with economic, cultural, and environmental factors. While some IPM strategies reduce pests, they may harm pollinators, reduce the efficiency of weed or disease management, or may increase costs relative to revenue. Pest protective row covers, in the form of fine-mesh netting (referred to as mesotunnels), are an effective alternative to pesticide use, but they are not without their challenges. While row covers exclude insect pests and the pathogens they vector, it is unknown how well non-vectored diseases can be managed underneath the row cover. The exclusion of …

Increasing Efficiency Of Finishing Beef Production: Strategies To Optimize Starch Digestion, Improve Flake Quality, And Reduce Methane Emissions, Ronald J. Trotta

Theses and Dissertations--Animal and Food Sciences

To continue to meet the demands of increasing food production and environmental sustainability, new strategies are needed to enhance the efficiency of finishing cattle production. A review of the literature identified several nutritional and physiological constraints that limit the ability for cattle to digest starch and absorb glucose from the small intestine. Comparative sequencing analyses revealed a missing region of the sucrase-isomaltase protein which could affect the capacity for starch digestion in cattle. Post-flaking sampling and handling recommendations were generated based on a series of experiments to improve estimates of starch availability and flaking consistency for commercial feedlots and laboratories. …

Management And Characterization Of Root-Knot Nematode (Meloidogyne Spp.) In Kentucky High Tunnels, Victoria Bajek

Theses and Dissertations--Plant and Soil Sciences

Kentucky is one of the most active adopters of high tunnels in the United States. Across the state, high tunnel growers have reaped the benefits of greater marketable yields, season extension, and protection from harsh weather. However, the high tunnel environment has increased soil temperatures and intensive crop production which has the potential to encourage root-knot nematode (RKN; Meloidogyne spp.) infestations. The extent and distribution of RKN in Kentucky were previously unknown. Two on-farm trials in infested high tunnels were conducted to determine whether grafting with RKN-resistant tomato rootstock is a viable management strategy. A statewide soil census to determine …

Personality Traits Of Dairy Calves And Their Relationship With Feeding Behavior, Activity, And Performance, Emily A. Michalski

Theses and Dissertations--Animal and Food Sciences

Detection of individual differences in personality traits of animals may prove beneficial for producers to help tailor management for individuals and to make selection decisions. Therefore, the objectives of this thesis were to

1) review and evaluate literature on relationships between individual cattle personality traits and feeding behavior, activity, and performance; and

2) evaluate and develop tests suitable for characterizing crossbred dairy-beef calves’ personalities and associations with behavioral patterns and performance.

The existing literature indicates that growth, intake, activity, and milk production measures from precision technologies have associations with cattle personality traits and behaviors identifiable through standardized tests. This indicates …

Improving Baking Quality Of Soft Red Winter Wheat In Kentucky Through Breeding And Sulfur-Nitrogen Fertility Management, Maria Paula Castellari

Theses and Dissertations--Plant and Soil Sciences

Soft Red Winter (SRW) wheat is an important crop grown on about 400,000 acres in Kentucky as a pivotal cash crop in the 3-crops-in-2-years rotation of corn, wheat, and soybean. The humid environment of Kentucky generates a high yielding wheat crop, with low protein concentration and weak gluten strength. This wheat is mainly sold to millers and used by the industry for cakes, pastries, cookies, and crackers. Conversely, there is a rapidly growing interest in identifying other value-added markets for this wheat different to commodity commercialization, such as artisan-baked goods and craft-distilled beverages. Evaluating the quality characteristics of wheat grown …

Ecological Risk Assessment Of Transgenic Conditional Lethality Systems For Genetic Biocontrol Strategies, Fernan Rodrigo Perez-Galvez

Theses and Dissertations--Entomology

Genetic strategies of insect pest control are receiving increased interest due to recent advances in genetic engineering. By introducing alleles that make males functionally sterile, genetically modified (GM) insects can be used in area-wide pest management programs similar to the Sterile Insect Technique (SIT). Genetic control strategies carry several potential benefits, including improved efficacy and specificity, lower operation costs, and reduced dependence on chemical insecticides, but their use is still controversial despite extensive technical documentation indicating their innocuity to humans and the environment. This hesitation is likely due to the novel nature of the approach.

While the first field applications …

Plant Cell Wall Composition And In Vitro Fermentation Characteristics Of Cool-Season Forage Grasses From Two Growing Seasons In Central Kentucky, Sophia Danielle Newhuis

Theses and Dissertations--Animal and Food Sciences

Grass cell walls are rich in cellulose, hemicellulosic arabinoxylan (AX) polysaccharides, and lignin. AX structural differences such as degree and pattern of branching and the ester-linked phenolic acid content could affect plants’ digestibility when used as forage for livestock. However, there is little information about how these structural elements change over the growing season in the vegetative tissue of cool-season perennial grasses. Enhanced information about the cell wall composition and carbohydrate structure of forage material will provide a foundation for expanding our knowledge of how forage cell wall carbohydrate structures are utilized by ruminants. The objectives of this study were …

Effects Of Fungicide Programs And Lower Leaf Removal On Wrapper Leaf Production In Connecticut Broadleaf Cigar Wrapper Tobacco, Caleb Haygan Perkins

Theses and Dissertations--Plant and Soil Sciences

In recent years, there has been increased demand for natural leaf cigar wrappers. Kentucky and Tennessee have been of recent interest as a new area for Connecticut Broadleaf production. Initial production experiences have shown that late-season frogeye leaf spot caused by the pathogen Cercospora nicotianae Ellis & Everh. may result in ‘green spot’ in cured leaf and cause a significant problem for producers of Connecticut Broadleaf cigar wrapper tobacco. Field trials were established in 2021 at Princeton, KY and 2022 in Mayfield, KY and Springfield, TN to evaluate effects of fungicide programs and lower leaf removal on wrapper production and …

Evaluation Of Chemical Control Options, Environmental Factors, And Management Practices Associated With Angular Leaf Spot (Pseudomonas Syringae Pv. Tabaci), Andrea Brooke Webb

Theses and Dissertations--Plant and Soil Sciences

Pseudomonas syringae pv. tabaci tox^- is the causal agent of angular leaf spot in dark tobacco. Since 2015, angular leaf spot has become the most significant foliar disease in dark tobacco production in Kentucky and Tennessee. Dark tobacco producers utilize one main tool, streptomycin sulfate, for the management of this bacterial disease. Resistance to streptomycin sulfate in P. syringae pv. tabaci isolates from dark tobacco fields in western Kentucky was first observed in 2015.

Field spray trials were developed to evaluate the efficacy of alternative active ingredients compared to the grower’s standard, streptomycin sulfate. Two separate field trials were …

Comparison Of Botanical Composition Methods And Change Over Time In Kentucky Pastures, Echo Elizabeth Gotsick

Theses and Dissertations--Plant and Soil Sciences

Botanical composition of pastures has been measured with numerous methods over the last century, but there have been limited direct comparisons between methods. The objective of this study was to compare botanical composition methods, to determine the most accurate and efficient method, and to access pasture composition change over time. Six farms with two pastures each were monitored across the state of Kentucky. Sampling occurred fall 2020 through fall 2022, three times a year using the following methods: step point, visual estimation, occupancy grid, and point quadrat (used as a reference method). The occupancy grid showed the highest similarity to …

Three Essays On The U.S. Beef Supply Chain: Production, Marketing, And Price Dynamics, Erdal Erol

Theses and Dissertations--Agricultural Economics

This dissertation contains three essays on select economic components of the U.S. beef industry. The first and second essays concentrate on the different economic problems in beef cattle production. The third essay evaluates the price dynamics and the impact of COVID-19 along the beef supply chain.

The first essay explores the economics of culling decisions in cow-calf operations in the U.S. with a novel application of a dynamic mathematical programming model. The results provide an optimal culling strategy under the base model and a range of optimal strategies that vary with respect to different components such as fertility probabilities, market …

Surveillance For Ticks And Tick-Borne Pathogens In Kentucky, Anna Rosalee Pasternak

Theses and Dissertations--Entomology

Tick-borne diseases are an emerging threat to human and animal health. In Kentucky, tick-borne disease surveillance has identified rising incidences of spotted fever rickettsiosis, ehrlichiosis, and Lyme disease. Since these diseases occur through the bites of infected ticks, effective prevention efforts are reliant upon knowing where the risk of exposure to tick bites exists. Historical data on tick distribution in Kentucky is variable, with very little reported on a statewide scale, leaving vector control workers, public health personnel, physicians, veterinarians, and others to rely on outdated, intermittent, or out-of-state information. In my dissertation, I surveyed ticks and select tick-borne pathogens …

Landscape Influences And Preventive Management For Drosophila Suzukii In Small Fruit Crops, Ryan William Kuesel

Theses and Dissertations--Entomology

Small fruit production has been greatly challenged by the repeated invasion of non-native arthropod pests, impacting economic feasibility, and increasing the need for insecticides. Spotted wing drosophila (Drosophila suzukii (Matsumura)) is the most recent invasive pest of small fruits. It causes damage by ovipositing beneath the skin of ripening fruits. Its wide-spread distribution and development of resistance to insecticides has resulted in the need for improved alternative management strategies for small fruit growers.

My surveys of D. suzukii at thirteen blackberry (Rubus fruticosus L.) and raspberry (Rubus idaeus L.) fields found that while D. suzukii was present …

Costs And Benefits Of Integrating Poultry Into Cover Crop - Vegetable Rotations, Viktor Halmos

Theses and Dissertations--Entomology

Integrated livestock systems were once common leading up to the 20th century where livestock generated manure that was then used to fertilizer crop production in a closed- or semi-closed system. However, with the industrialization of agriculture in the mid to late 20th century, specialization drove simplified systems that segregated livestock from cropping systems. This segregation led to nutrient surpluses occurring in livestock operations, and nutrient demands in cropping systems creating a plethora of environmental issues. With the increased awareness of environmental issues, a renewed interest in integration has driven producers and researchers to experiment with integration again. For research, the …

Linking Previous Experiences To Behavior And Health In The Honey Bee (Apis Mellifera), Rebecca R. Westwick

Theses and Dissertations--Entomology

An organism’s ability to respond to changing conditions can be vital to its success. Indeed, plasticity is a common feature of living organisms. Much of the research in this area, though, has focused on effects caused by environmental conditions. What has received relatively less attention is how social experiences and broader features of an organism’s social environment can lead to long-lasting changes in health and behavior. This knowledge gap exists despite the well-documented existence of health and behavioral effects after social interactions in certain taxa such as humans.

Social insects such as honey bees provide an excellent opportunity to better …

Understanding The Effects Of Age, Environmental Conditions, And Placement On Cockroach Gel Bait Performance, Isabelle Lucero

Theses and Dissertations--Entomology

Cockroach baits are one of the most effective tools used for German cockroach (Blattella germanica L.) control. This is due in part to the number of cockroach baits on the market with various matrix compositions and active ingredients, aiding in the control of resistant (physiologically and behaviorally) cockroach populations through bait rotation. However, it remains unclear how cockroach gel baits perform over time and under different environmental conditions. Therefore, we aged six cockroach gel baits for varying times (24 hours, one month, three months, six months) and at three relative humidities (15%, 40%, and 80%), and tested their performance …

Community Supported Agriculture Values: A Comparison Across Groups, Thomas B. Pierce

Theses and Dissertations--Agricultural Economics

Community Supported Agriculture (CSA) programs offer consumers the chance to share the risk with farming operations while gaining access to fresh, local foods. While research on CSA shareholder values such as share affordability or the local impact of participation has been conducted in the past decade and beyond, less attention has been paid to direct value-mapping of the shareholders themselves. This research seeks to determine consumer values around the CSA purchasing decision using the Best-Worst Scaling Approach. Based on a focus group discussion with CSA shareholders in a university wellness voucher program, we used affinity diagramming to develop a list …

Manipulating Species Diversity: Environmental Impacts In Row Crop, Livestock, And Grassland Agroecosystems, Alayna A. Jacobs

Theses and Dissertations--Plant and Soil Sciences

The diversity of living species in an agroecosystem affects both natural resources and agricultural production efficiency. The rise of managed plant monocultures has allowed agricultural yields to increase over time. However, simplifying agroecosystems affects the capacity of the system to sustainably provide clean air, water, and productive soils essential for continued food and fiber production. This dissertation manipulates species diversity in row crop and forage agroecosystems prevalent in the Eastern United States and tracks the associated environmental and agricultural production consequences.

In row crop agroecosystems, increasing plant diversity with winter cover crops has been suggested as a strategy to increase …

Farmers’ Market Incentive Program As An Intervention For Improving Behavior Regarding Fruit And Vegetable Consumption In Children And Adolescents, Madison Blades

Theses and Dissertations--Nutrition and Food Systems

Background: Previous research shows that there is low consumption of fruits and vegetables in children and adolescents, specifically those residing in the state of Kentucky which is ranked the lowest of all states in fruit and vegetable (F/V) consumption. The lack of F/V in a diet of someone during their developmental ages can result in negative health outcomes in the future.

Objective: To determine if the use of a farmers’ market incentive program as a nutritional intervention affects the consumption of F/V in children and adolescents.

Methods: 261 children and adolescents, ages 3-14, from 160 families participated in a 10-week …

Understanding The Cellular And Physiological Mechanisms Of Fertilization And Early-Stage Seed Development, Mohammad Foteh Ali

Theses and Dissertations--Plant and Soil Sciences

Flowering plants have evolved a unique double-fertilization process. Two sperm cells fuse with two female gametophytic cells, the egg and central cells within the ovule, giving rise to the embryo and endosperm, respectively. Sperm cells in flowering plants are nonmotile and delivered in close proximity to the egg and central cells by the pollen tube. Flowering plants have established filamentous actin (F-actin) based sperm nuclear migration system for successful fertilization. Prior to fertilization, the female gamete forms a mesh-like structure of F-actin that shows constant inward movement from the plasma membrane periphery to the center of the cell where the …

Survey Of Herbicide Resistance And Seed Fate Of Italian Ryegrass (Lolium Perenne Ssp. Multiflorum) In Kentucky, Amber Lynn Herman

Theses and Dissertations--Plant and Soil Sciences

Herbicide resistance is not a new problem for farmers in Kentucky, although the identification of herbicide resistant weed species continues to increase. Italian ryegrass (Lolium perenne ssp. multiflorum) is a problematic weed in Kentucky’s soft red winter wheat that has historically been documented as herbicide resistant in isolated locations. A greenhouse herbicide screen was conducted to further understand the level of glyphosate, pinoxaden, and pinoxaden plus fenoxaprop resistance in Kentucky Italian ryegrass populations. The preliminary screen and dose responses indicate there is one Italian ryegrass population resistant to glyphosate and two populations resistant to pinoxaden along with pinoxaden …

Mechanisms Of Programmed Nutrition In Finishing Cattle In Vivo And Ruminal Parameters Of Amaize Supplementation In Vitro, Amanda Pesqueira Schiff

Theses and Dissertations--Animal and Food Sciences

Programmed Nutrition Beef Program (Alltech Inc.) is a dietary supplement that contains Aspergillus oryzae fermentation extract with α-amylase activity that could reduce the use of feed additives such as monensin and tylosin in conventional feedlot diets. This study examines the changes in rumen fermentation resulting from feeding monensin/tylosin and Programmed Nutrition Beef Finisher. The goal was to determine if these shifts in rumen fermentation contribute to the Programmed Nutrition response observed in vivo. This study also analyzes how different levels of α-amylase (Amaize)supplementation impacts feedstuff degradation and utilization in vitro. In vivo experiment used eight steers in a replicated …

Use Of Heterothallic Mat Deletion Strains Of Fusarium Graminearum As Test Mates In Crosses To Evaluate The Genetics Of Pathogenicity And Fitness, Gabdiel Emmanuel Yulfo-Soto

Theses and Dissertations--Plant Pathology

Fusarium Head Blight (FHB), caused by Fusarium graminearum sensu stricto and other members of the F. graminearum species complex (FGSC), is a plant disease that occurs on cereal crops worldwide. FHB causes yield losses not only by reducing grain weight, but also by contaminating the kernels with dangerous trichothecene mycotoxins, especially deoxynivalenol (DON). There is a high degree of genotypic and phenotypic variation among pathogen species and strains, but current FHB risk assessment models and treatments do not account for pathogen diversity. Therefore, it is difficult to predict what will happen if a new, potentially more aggressive variant is introduced, …

An Improved Understanding Of Diplodia Ear Rot In Kentucky Corn, Nolan Ryan Anderson

Theses and Dissertations--Plant Pathology

Stenocarpella maydis and Stenocarpella macrospora are both causal agents of Diplodia ear rot (DER) of corn in the U.S. The current prevalence and distribution of each is unknown worldwide. Signs and symptoms of DER include white mold on and between kernels, bleached husks, and pycnidia visible in the cob pith. The term hidden Diplodia describes when no mycelia or bleached husk is present, but pycnidia are still visible inside the cob. This phenomenon is reported to be caused by late infections of Stenocarpella spp. New fungicide nozzle technology has been promoted to increase spray coverage in the lower canopy, which …