Agriculture Commons^™

Recombinant Promoter (Muascsv8cp) Driven Totiviral Killer Protein 4 (Kp4) Imparts Resistance Against Fungal Pathogens In Transgenic Tobacco, Debasish Deb, Ankita Shrestha, Indu B. Maiti, Nrisingha Dey

Kentucky Tobacco Research and Development Center Faculty Publications

Development of disease-resistant plant varieties achieved by engineering anti-microbial transgenes under the control of strong promoters can suffice the inhibition of pathogen growth and simultaneously ensure enhanced crop production. For evaluating the prospect of such strong promoters, we comprehensively characterized the full-length transcript promoter of Cassava Vein Mosaic Virus (CsVMV; -565 to +166) and identified CsVMV8 (-215 to +166) as the highest expressing fragment in both transient and transgenic assays. Further, we designed a new chimeric promoter ‘MUASCsV8CP’ through inter-molecular hybridization among the upstream activation sequence (UAS) of Mirabilis Mosaic Virus (MMV; -297 to -38) and CsVMV8, as the core …

Determinants Of Weanling Thoroughbred Auction Prices, Charlotte R. Hansen, C. Jill Stowe

Agricultural Economics Faculty Publications

Determinants of prices of 1,302 weanling Thoroughbreds sold at the 2010 Keeneland November Breeding Stock Sale are investigated. A hedonic pricing model is adopted to identify price determinants, and the corresponding marginal values of those determinants are estimated. Prices were responsive to pedigree quality variables, including the sire's stud fee, the stage of the sire's breeding career, and whether the dam or the dam's progeny had earned “black type.” In addition, individual weanling characteristics such as gender, age, state of birth, and sale placement influenced price. Results can be used as a decision tool by both buyers and sellers.

Cover Crops And Fertilization Alter Nitrogen Loss In Organic And Conventional Conservation Agriculture Systems, Rebecca E. Shelton, Krista L. Jacobsen, Rebecca L. Mcculley

Horticulture Faculty Publications

Agroecosystem nitrogen (N) loss produces greenhouse gases, induces eutrophication, and is costly for farmers; therefore, conservation agricultural management practices aimed at reducing N loss are increasingly adopted. However, the ecosystem consequences of these practices have not been well-studied. We quantified N loss via leaching, NH₃ volatilization, N₂O emissions, and N retention in plant and soil pools of corn conservation agroecosystems in Kentucky, USA. Three systems were evaluated: (1) an unfertilized, organic system with cover crops hairy vetch (Vicia villosa), winter wheat (Triticum aestivum), or a mix of the two (bi-culture); (2) an organic …

Missed Work Due To Occupational Illness Among Hispanic Horse Workers, Ashley M. Bush, Susan C. Westneat, Steven R. Browning, Jennifer Swanberg

Kentucky Injury Prevention and Research Center Faculty Publications

Occupational illnesses are inadequately reported for agriculture, an industry dominated by a vulnerable Hispanic population and high fatal and nonfatal injury rates. Work-related illnesses can contribute to missed work, caused by a combination of personal and work factors, with costs to the individual, employer, and society. To better understand agricultural occupational illnesses, 225 Hispanic horse workers were interviewed via community-based convenience sampling. Descriptive statistics, bivariate analyses, and log binomial regression modeling were used to: (1) describe the prevalence of missed work due to work-related illnesses among Hispanic horse workers, (2) examine work-related and personal factors associated with missed work, and …

Asymmetric Price Volatility Transmission Between U.S. Biofuel, Corn, And Oil Markets, Sayed Saghaian, Mehdi Nemati, Cory Walters, Bo Chen

Agricultural Economics Faculty Publications

Linkages between agricultural commodity and energy prices have become more complex with increased ethanol production. The concern is whether the new corn–ethanol links lead to volatility-spillover transmission between food and energy prices. We investigate asymmetric volatility spillovers between oil, corn, and ethanol prices using a BEKK-multivariate-GARCH approach. Additionally, we use daily, weekly, and monthly futures prices to examine whether the use of different-frequency data leads to inconsistent results. The results support the existence of asymmetric volatility transmission between corn and ethanol prices. Furthermore, the volatility-spillover effects are different for the different-frequency prices, and positive and negative price changes generate inconsistent …

Coffee Market In China, Ran Zhu

Theses and Dissertations--Agricultural Economics

Although China is generally known as a tea-consuming country, both the production and consumption of coffee in China has seen double-digit growth in the last decade. This upward trend is projected to continue as long as investment is sustained and levels of disposable income continue to increase. In this rapidly expanding market, it is important for coffee producers and retailers in China to understand the preferences of emerging Chinese coffee consumers. Using survey data from Hubei and Zhejiang, China, we apply a Tobit regression model to analyze Chinese coffee consumers. Results show that the length of time consumers have been …

Emerald Ash Borer (Coleoptera: Buprestidae) Host Expansion; Trading An Optimal Host For Enemy Free Space?, David G. Olson

Theses and Dissertations--Entomology

Emerald ash borer (EAB), Agrilus planipennis (Coleoptera: Buprestidae), is an aggressive invader from Asia that has killed millions of trees in North America. Recently EAB has been documented developing in a novel host, white fringetree, Chionanthus virginicus. I evaluated larval performance in two common ash species and white fringetree by infesting excised bolts with emerald ash borer eggs. In addition I evaluated several plant characteristics to determine which most influence larval development. I also conducted choice and no choice assays using the classical biological control agent, Tetrastichus planipennisi (Hymenoptera: Eulophidae), to assess its ability to locate larval EAB in …

Dna Barcoding As A Tool For Species Discovery And Documentation In The Superfamily Ichneumonoidea, Sarah Meierotto

Theses and Dissertations--Entomology

Changes to traditional taxonomic methods to incorporate new technologies and methods have already improved the quality of species hypotheses, but more work can be done to improve the speed of new species documentation. The mitochondrial COI DNA barcode has been successfully used to identify species with high accuracy since the early 2000s, and has been used in conjunction with morphological examinations and other DNA markers to discover and delimit new species. This thesis explores the application of DNA barcodes as the primary data for delimitation and diagnosis of new species of ichneumonoids.

The genera Zelomorpha and Hemichoma are revised and …

The Influence Of Transformational Middle Leaders On Work-Life Balance, Timothy D. Tanner

Theses and Dissertations--Education Sciences

Work-life balance is a key indicator of employee satisfaction, retention, and social health as well as organizational creativity and productivity. These dual benefits for employee and employer have generated interest in promoting work-life balance. Supervisors who operate from a transformational leadership framework have been linked to greater work-life balance among employees (Lamm, 2011; (Kutilek, Conklin, & Gunderson, 2002). The role of a supportive organizational culture is also central (Lewis, 2001).

In this study, Cooperative Extension Service agents (N = 1390) participated in a nationwide survey exploring the relationship between rated levels of transformational leadership among district directors, work-life balance, …

Assessing Intra-Event Phosphorus Dynamics In Drainage Water Using Phosphate Stable Oxygen Isotopes, William Ford Iii, Mark R. Williams, Megan B. Young, Kevin W. King, Eric Fischer

Biosystems and Agricultural Engineering Faculty Publications

Quantifying fluxes and pathways of dissolved reactive phosphorus (DRP) in tile-drained landscapes has been hampered by a lack of measurements that are sensitive to P fate and transport processes. One potential tool to help understand these dynamics is the oxygen isotope signature of phosphate (δ¹⁸O_PO4); however, its potential benefits and limitations are not well understood for intra-event dynamics at the field scale. The objectives of this study were to quantify intra-event variability of δ¹⁸O_PO4 signatures in tile drainage water and assess the efficacy of δ¹⁸O_PO4 to elucidate mechanisms and flow …

Influence Of Kernel Shape And Size On The Packing Ratio And Compressibility Of Hard Red Winter Wheat, Marvin C. Petingco, Mark E. Casada, Ronaldo G. Maghirang, Sidney A. Thompson, Samuel G. Mcneill, Michael D. Montross, Aaron P. Turner

Research and Education Center at Princeton Faculty Publications

Grain compaction occurs during bin storage, and its determination is important for the grain mass estimation needed for inventory and auditing. The degree of compaction is dependent on grain type, bin type, moisture content, amount of grain, initial grain bulk density, coefficients of friction, lateral-to-vertical pressure coefficient, and variation in kernel size. Previous studies have correlated several of these parameters, such as bulk density and grain packing, with moisture content. This study investigated the influence of wheat kernel shape and size distribution on packing ratio and compressibility. Two dockage-free hard red winter (HRW) wheat samples, with no shrunken or broken …

On-Farm Utilization Of Precision Dairy Monitoring: Usefulness, Accuracy, And Affordability, Elizabeth A. Eckelkamp

Theses and Dissertations--Animal and Food Sciences

Precision dairy monitoring is used to supplement or replace human observation of dairy cattle. This study examined the value dairy producers placed on disease alerts generated from a precision dairy monitoring technology. A secondary objective was calculating the accuracy of technology-generated disease alerts compared against observed disease events. A final objective was determining the economic viability of investing in a precision dairy monitoring technology for detecting estrus and diseases.

A year-long observational study was conducted on four Kentucky dairy farms. All lactating dairy cows were equipped with a neck and leg tri-axial accelerometer. Technologies measured eating time, lying time, standing …

The Impacts Of Honey Bee Queen Stress On Worker Behavior And Health, Sarah R. Preston

Theses and Dissertations--Entomology

Pesticides, poor nutrition, parasites and diseases work synergistically to contribute to the decline of the honey bee. Heritable sub-lethal behavior/immune effects may also contribute to the decline. Maternal stress is a common source of heritable immune/behavior deficits in many species. A stressed honey bee queen has the potential to pass such deficits on to worker bees. Using a repeated measures design, this study will determine whether the health of worker bee is reduced by a cold stress on the queen by analyzing egg hatch rate and protein content, emergence rate, and adult aggression and immune function for offspring laid before …

The Impact Of Biofuel Policies On Overshooting Of Agricultural Prices, Mahdi Asgari

Theses and Dissertations--Agricultural Economics

The Federal Reserve has increased nominal interest rates since early 2016. It is expected that commodity prices will drop in response to this monetary intervention. The overshooting hypothesis explains that commodity prices are more flexible than manufacturing prices and therefore are more volatile. In this situation, it is expected that agricultural commodities decline significantly (i.e., overshoot) and gradually return to their long-run equilibrium. This adjustment behavior has implications for income stability and financial viability of farmers.

This research contributes to the overshooting literature by including the energy sector in the overshooting model. The interlinks between energy and other sectors in …

Two Essays On Whole Farm Modeling And Crop Marketing In Western Kentucky, Benjamin A. Martin

Theses and Dissertations--Agricultural Economics

This thesis is composed of two essays that investigate whole farm planning and crop marketing in western Kentucky. In the first essay, contracting decisions between food corn producers and a mill are analyzed to observe factors affecting the bushel amount farmers contract. Unbalanced panel data containing seven years’ worth of pricing and contract information are used with a fixed-effects model to generate parameter estimates and quantify their effect on bushels contracted. It was found that contract attributes, market condition, and relationship-specific assets had a significant effect on producers’ food corn contracting decisions. The second essay utilizes mixed-integer programming to optimize …

Influence Of Dietary Ractopamine And Supranutritional Supplementation Of Vitamin E On Proteome Profile Of Postmortem Beef Longissimus Lumborum Muscle, Hyun Mok Kim

Theses and Dissertations--Animal and Food Sciences

The effects of dietary ingredients on the proteome profile of postmortem beef longissimus lumborum (LL) muscle were evaluated. In the first experiment, the influence of dietary ractopamine on the whole-muscle proteome of beef LL was examined. Five proteins were differentially abundant between ractopamine-fed (RAC) and non-ractopamine fed (CON) groups. The differentially abundant proteins were over-abundant in RAC and were related to muscle structure development (F-actin-capping protein subunit beta-2 and PDZ and LIM domain protein-3), chaperone (heat shock protein beta-1), oxygen transportation (myoglobin), and glycolysis (L-lactate dehydrogenase A chain). These findings indicated that ractopamine influences the abundance of proteins associated with …

Leadership Styles Of State Extension Specialists, K. Amy Lawyer

Theses and Dissertations--Education Sciences

Cooperative extension is one of three components, along with teaching and research that form the mission of land grant universities. The focus of extension work is to take knowledge gained through research conducted at the university, and disseminate the information, in a practical manner to the end user. In most instances, extension work revolves around agriculture. Within the extension system are personnel that help to foster this program of educating clientele who work in the agricultural industry. County level agents are in place to teach and address the needs of local constituents, specialists are generally housed at the university campus …

Factors Contributing To Job Satisfaction, Retention, And Attrition Of Agricultural Educators: A Synthesis Of Research, Lee Nolan Thomsen

Theses and Dissertations--Community & Leadership Development

In recent years, School-Based Agricultural Education has been facing a shortage of secondary teachers, due in part to low retention rates of these valuable educators. In light of this shortage, a multitude of research has been conducted throughout the country on challenges faced by agricultural educators, some as indicators of intent to leave the profession. This thesis sought to synthesize the research conducted on job satisfaction, retention, and attrition of School-Based Agricultural Educators order to identify prevalent problems facing these teachers which may contribute to the decision to leave the classroom. From the research, seven themes emerged as job-related factors …

Identifying Mechanisms Of Host Plant Specialization In Aphis Craccivora And Its Bacterial Symbionts, Thorsten Hansen

Theses and Dissertations--Entomology

Many insects form close relationships with microbial symbionts. Insect symbionts can provide novel phenotypes to their hosts, including influencing dietary breadth. In the polyphagous cowpea aphid, Aphis craccivora, the facultative symbiont Arsenophonus improves aphid performance on one host plant (locust), but decreases performance on other plants. The goal of my thesis was to investigate the mechanism by which Arsenophonus facilitates use of locust. First, I assembled an Aphis craccivora-Arsenophonus-Buchnera reference transcriptome to conduct RNAseq analysis, comparing gene expression in aphids feeding on locust and fava, with and without Arsenophonus infection. Overall, few transcripts were differentially …

Impact Of Selected Integrated Pest Management Techniques On Arthropods In Cucurbit Production Systems, Amanda R. Skidmore

Theses and Dissertations--Entomology

Cucurbits (i.e. squash, melons, pumpkins, gourds) are high value crops of global importance. Insect pests in these systems are often controlled by chemical insecticides, which are not always effective and can be damaging to the environment. Many integrated pest management (IPM) techniques have been developed for the control of pests in these systems, with a goal of improving system stability and reducing chemical inputs. The overarching goal of my research was to investigate the impact of select IPM techniques on arthropod populations and yield in organic and conventional cucurbit systems.

This dissertation can be divided into three major projects which …

The Mechanism Of Rna Interference In Arthropods, June-Sun Yoon

Theses and Dissertations--Entomology

RNA interference (RNAi) is a useful reverse genetics tool for investigation of gene function as well as for practical applications in many fields including medicine and agriculture. Due to the variability in RNAi efficiency, RNAi-based methods are currently being developed for controlling only coleopteran insects which are known to be amenable to RNAi. The first chapter of my thesis includes findings from research to investigate what are the factors that make coleopteran insects relatively more efficient in RNAi. I used Colorado potato beetle (CPB), Leptinotarsa decemlineata and its cell line (Lepd-SL1) as study models to identify genes that play key …

Bee Conservation In Urban Landscapes: Assessing Bee Assemblages, Bee–Attractiveness, And Nutritritional Value Of Woody Landscape Plants And Mitigating Potential Bee Hazard From Neonicotinoid Insecticides, Bernadette Maria Mach

Theses and Dissertations--Entomology

Public awareness of declining pollinator populations has increased interest in creating “bee–friendly” urban landscapes. I quantified bee visitation and assemblages of 72 species of flowering woody plants common in urban landscapes. I found strong plant species effects and variation in seasonal activity of particular bee taxa but no overall differences in bee visitation or genus diversity between native versus nonnative species or trees versus shrubs. Analysis of pollen from a subset of these plants revealed small but statistically significant differences in total and essential amino acids between native and nonnative species and trees and shrubs, although each group had species …

Corn Grain Yield Components And Nutrient Accumulation In Response To Nitrogen, Plant Density And Hybrid, Maria Julia Santoro

Theses and Dissertations--Plant and Soil Sciences

Modern maize hybrids exhibit higher yields, increased biomass production, stress tolerance and greater nitrogen (N) use efficiency. Increased biomass accumulation can influence nutrient uptake and lead to increased nutrient removal. Hybrids were tested at seeding rates (SR) of 74000 (low) and 148000 (supraoptimal) plants ha^-1 and at N rates of 0 (deficient) and 390 (non-limiting) kg N ha^-1. Plants were sampled at V7, V14, R3, R5 and R6 and separated into vegetative and reproductive fractions for determination of dry matter and N accumulation. Grain yield was harvested at R6.

The high SR and high N treatment combination …

Evaluating Hemp (Cannabis Sativa) As A Forage Based On Yield, Nutritive Analysis, And Morphological Composition, Carol Elizabeth Stringer

Theses and Dissertations--Plant and Soil Sciences

This experiment examined the forage potential of hemp (Cannabis sativa) and kenaf (Hibiscus cannabinus). The objectives were to evaluate yield and forage nutritive value (i.e. NDF, ADF, ADL, IVTD, and CP) fluctuations over the course of a growing season based on planting date, morphological composition, and management. Three types of hemp (grain, fiber, and a dual- purpose type) and kenaf were planted on two dates and were sampled approximately every two weeks throughout the growing season at the University of Kentucky (UK) Research Farm in Lexington, KY. Subsamples were separated into morphological components (i.e. leaf, flowers, stem, core fiber, and …

Measured Soil Hydraulic Properties As Rzwqm2 Input To Simulate Soil Water Dynamics And Crop Evapotranspiration, Saadi Sattar Shahadha

Theses and Dissertations--Plant and Soil Sciences

Agricultural system models integrate many different processes that cannot all be measured in field experiments and help quantify soil water dynamics, crop evapotranspiration, and crop growth with high temporal resolution. Understanding soil water dynamics and crop evapotranspiration is essential to improve agricultural management of field crops. For example, the interaction between nitrogen application rate and water dynamics is not sufficiently understood. In most cases, model simulations deviate from field measurements, especially when model input parameters are indirectly and unspecifically derived. The extent to which measured soil hydraulic property inputs decrease the discrepancy between measured and simulated soil water status is …

Establishing Growing Degree Day Estimates To Predict Critical Growth Stages In Soft Red Winter Wheat, Ethan J. Snyder

Theses and Dissertations--Plant and Soil Sciences

Predicting developmental growth stages in soft red winter wheat (Triticum aestivum L.) (SRWW) could improve agronomic management in Kentucky. However, predicting SRWW development is complex due to vernalization requirement and photoperiod sensitivity differences of cultivars. The objectives of this study are to (1) determine ability of Kompetitive Allele Specific PCR (KASP) genotyping to predict phenotype; (2) determine the relative vernalization requirement (RVR) of 50 SRWW cultivars in a greenhouse (GH) assay; and (3) measure growing degree-days (GDD) required by cultivars to reach eight growth stages in a field assay. Fifty SRWW cultivars were characterized with 14 KASP markers for …

Bacterial Inoculants, Endophytic Bacteria And Their Influence On Nicotiana Physiology, Development And Microbiome, Andrea Marisa Sanchez Barrios

Theses and Dissertations--Plant and Soil Sciences

Soil and root microbial communities have been studied for decades, and the incorporation of high-throughput techniques and analysis has allowed the identification of endophytic/non-culturable organisms. This has helped characterize and establish the core microbiome of many model plant species which include underground and aboveground organs. Unfortunately, the information obtained from some of these model plants is not always transferable to other agronomic species. In this project, we decided to study the microbiome of the Nicotiana genus because of its importance in plant physiological and plant-microbe interactions studies. The data obtained was used as baseline information that allowed us to better …

Chemical Topping Burley Tobacco, Mitchell D. Richmond

Theses and Dissertations--Plant and Soil Sciences

The act of topping tobacco (Nicotiana tabacum L.) involves the removal of the terminal bud or inflorescence of the tobacco plant. This practice ordinarily is accomplished by manually removing the top of each tobacco plant in an entire field which is labor intensive and costly. Chemical topping utilizes sucker control products to inhibit the terminal bud and axillary bud growth without manually removing the top of the tobacco plant. There were several research objectives in order to determine the utility of a chemical topping system: 1) determine if burley tobacco could be chemically topped with currently registered suckercide products …

Can Increasing Grass-Fungal Endophyte Symbiotic Diversity Enhance Grassland Ecosystem Functioning?, Mahtaab Bagherzadeh

Theses and Dissertations--Plant and Soil Sciences

The relationship between biodiversity and ecosystem functioning is important in maintaining agroecosystem sustainability. Plant-microbe symbioses, such as exists between the grass tall fescue (Schedonorus arundinaceum) and the asexual fungal endophyte Epichloë coenophiala, can be utilized to enhance agroecosystem functions, such as herbivore resistance. “Novel” E. coenophiala strains that vary in the production of mammal- and insect-toxic compounds have been identified, inserted into tall fescue cultivars, and are planted in pastures globally. Novel fungal endophyte-tall fescue associations may have divergent ecosystem function effects. This study assessed effects of different fescue-endophyte symbiotic combinations on pasture ecosystem function, including aboveground …

Engineering Zinc Oxide Nanoparticles To Be Used As Nanofertilizers, Zeinah Elhaj Baddar

Theses and Dissertations--Plant and Soil Sciences

Zinc deficient soils, or soils with low Zn bioavailability, are widespread, which exacerbates Zn deficiency in human as crops grown on these soils have low Zn content. Often crop yields are also compromised. Fertilizers based on soluble Zn salts often have limited efficacy in such soils. In this research, we evaluate the performance of polymer coated and bare ZnO nanoparticles (NPs) in an attempt to overcome limitations of soluble Zn salts in alkaline soils. We first synthesized 20-30 nm bare ZnO NPs with different surface chemistries to impart colloidal stability to the particles. Bare ZnO were treated in phosphate solution …