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A Hedonic Analysis Of Factors Impacting The Value Of Planters On The Used Machinery Market, John Allison Jr., Tyler B. Mark, Kenneth H. Burdine, Jordan M. Shockley

Agricultural Economics Faculty Publications

A hedonic model was employed to examine factors that influence the resale price of row crop planters on the used machinery market. Planter sale data from 2016 to 2018 were utilized to conduct the analysis. Results suggested that the primary factors impacting planter resale prices were make, age, condition, planter configuration, row number, and row spacing. As a function of age (depreciation), planter values were generally determined to decrease at a decreasing rate. Finally, it was determined that there was a significant interaction between the variables make and age, suggesting that different planter makes depreciate differently.

Functional Antagonism Of Wri1 And Tcp20 Modulates Gh3.3 Expression To Maintain Auxin Homeostasis In Roots, Que Kong, Pui Man Low, Audrey R. Q. Lim, Yuzhou Yang, Ling Yuan, Wei Ma

Kentucky Tobacco Research and Development Center Faculty Publications

Auxin is a well-studied phytohormone, vital for diverse plant developmental processes. The GH3 genes are one of the major auxin responsive genes, whose expression changes lead to modulation of plant development and auxin homeostasis. However, the transcriptional regulation of these GH3 genes remains largely unknown. WRI1 is an essential transcriptional regulator governing plant fatty acid biosynthesis. Recently, we identified that the expression of GH3.3 is increased in the roots of wri1-1 mutant. Nevertheless, in this study we found that AtWRI1 did not activate or repress the promoter of GH3.3 (proGH3.3) despite of its binding to proGH3.3. Cross-family …

Net Effects Of Wild And Managed Birds In Agroecosystems, Karina Garcia

Theses and Dissertations--Entomology

Agricultural intensification and expansion have reduced biodiversity in agroecosystems, jeopardizing the ecosystem services that nature provides to humans in these landscapes including wildlife-mediated pest control. Among these purveyors of ecosystem services are birds, who can provide services to agroecosystems by consuming arthropod pests. Yet some bird species also act as pests by consuming crops. Herein, I use molecular diet analysis through high-throughput sequencing on DNA extracted from bird fecal samples to examine birds’ diet and classify bird species as consumers of major strawberry pests (Lygus spp.). Additionally, I use targeted PCR approaches to determine which bird species consumed strawberries. …

A Functional Genomics Approach To Overwintering Mechanisms In Insects, Emily Allison Wheeler Nadeau

Theses and Dissertations--Entomology

Insects living in temperate and polar environments have developed numerous adaptations to increase survival at low temperatures. A majority of insects are freeze-intolerant and die from internal ice formation, but some are freeze-tolerant and can survive ice formation in extracellular spaces. Both categories of insects prepare for winter with a combination of seasonal and rapid acclimation responses, which differ both in time course and in underlying mechanisms. In this dissertation, I examine adaptations for winter survival in several insect species with a specific focus on molecular mechanisms. To better understand the underpinning mechanisms of these adaptations, I leverage functional genomics …

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 …

Epidemiology And Management Of Frogeye Leaf Spot Of Soybean: Damage Thresholds, Efficacy And Profitability Of Foliar Fungicides, Jhonatan Paulo Barro

Theses and Dissertations--Plant Pathology

Frogeye leaf spot (FLS), caused by Cercospora sojina, is an economically important disease of soybean in many parts of the world where soybean is grown, including the United States. A meta-analytic approach was used to summarize a data set of 66 uniform field research trials conducted to evaluate fungicide efficacy against FLS on soybean. The dataset spanned 10 years (2012 to 2021) of experiments conducted across eight states in the U.S., including Alabama, Arkansas, Illinois, Iowa, Kentucky, Louisiana, Mississippi and Tennessee. First, the relationship between FLS severity and soybean yield was investigated. A significant negative slope obtained through random …

Application Of Mass Spectrometry For Characterization Of Plant-Based Phenolics And Alkaloids, Masoumeh Dorrani

Theses and Dissertations--Chemistry

Plant-derived compounds have the potential to produce value-added compounds with a variety of applications. For example, the lignin part of the lignocellulosic biomass, produced in large quantities as waste from the paper and pulp industries, is a rich source of phenolics with potential applications in the renewable energy sector, pharmaceutical, and chemical industries. On the other hand, plant alkaloids are the primary source for developing plant-derived therapeutics. Unfortunately, the recalcitrant nature of plant cell walls, low extraction yields of small secondary metabolites, and the lack of effective analytical methods for a rapid and accurate identification of plant-based compounds and plant’s …

Building Capacity For Cool Season Vegetable Production In Kentucky: Strengthening Supply Chains Through Crop Model Development And Analysis Of A Farm-To-Institution Market, Chelsea Jo Maupin

Theses and Dissertations--Plant and Soil Sciences

Cool season vegetable crops are suitable for both direct-to-consumer (DTC) and farm-to-institution (FTI) markets in central Kentucky. However, crop planning for predictable harvest is challenging. Seasonality issues can be detrimental to FTI markets wherein institutions require consistent, large volumes of product. This research investigates both production and market aspects of salad crops in central Kentucky, through development of growing degree day (GDD) crop models for loose-leaf lettuce (Latuca sativa), carrots (Daucus carota subsp. sativus), and spinach (Spinacia oleracea), and through a case study analysis for a FTI initiative called the Salad Bar Program. Simple …

Effects Of Physiological Stage And Diet On Drosophila Suzukii Olfaction, Aerianna Shindindowi Littler

Theses and Dissertations--Entomology

Massive economic damage by spotted-wing drosophila (SWD), Drosophila suzukii, results from their unique egg laying behavior. Gravid SWD flies employ a complex suite of behaviors to find fruit with the optimum firmness and chemistry. We tested for SWD attraction to various fruits and found overripe raspberries to be most attractive to gravid flies which was unexpected since they oviposit in ripe fruit. We next tested the same choice assay in a T-maze and found that the results were comparable. We also found discrete odor profiles among the ripening stages. When testing for sugars and CO2 concentrations from field-collections, overripe …

Gene Silencing Provides Insights Into Bark Beetle Biology And Creates Potential For Broad Scale Forest Protection, Beth R. Kyre

Theses and Dissertations--Entomology

Dendroctonus bark beetles are among the most economically and ecologically significant forest pests in North America and play a critical role in the overall health of conifer forest ecosystems. Dendroctonus bark beetles influence ecosystem benefits and biodiversity and drive forest succession, and adversely affect timber production, forest management, and recreation. As temperatures surge and climatic fluctuations become more extreme, catastrophic bark beetle outbreaks are increasing in frequency, escalating pressures on highly vulnerable conifer forests already compromised by heat and drought. Eruptive outbreaks of Dendroctonus beetles are largely unhindered by traditional silvicultural management; these practices further disrupt forest ecosystem services, including …

An Evaluation Of Eragrostis Tef For Future Cultivar Development, Eric Wayne Luteyn

Theses and Dissertations--Plant and Soil Sciences

The many benefits of utilizing teff (Eragrostis tef) as small grain is well documented in journal publications. Over time the domestication of this species has become essential to the diets of the local population and the livestock living in the African highlands. Current research points to a high diversity of trait characteristics found in many teff populations and the potential utilization of these traits to increase desirable characteristics in both grain and forage varieties. With the overarching goal of adding to what is already known about teff, this study evaluates the different traits that are of interest to …

Remote Sensing For Quantifying C3 And C4 Grass Ratios In Pastures, Jordyn Alyssa Bush

Theses and Dissertations--Plant and Soil Sciences

The following studies investigate the accuracy and practicality of exploiting the color dichotomy present between C₃ and C₄ grass species to estimate their respective proportions from drone or camera captured imagery. Understanding the proportions of C₃ and C₄ grasses in pastures is vital to sound decision making for livestock production. The ability to monitor these proportions remotely will also allow for large scale monitoring as well as detection of changes in botanical composition over time and in response to weather events, management, or climate change. A free green canopy cover (GCC) analyzing software, Canopeo, was used …

Quantifying Crop Phenology For Food Sustainability Under Climate Change: Integration Of Remote Sensing, Machine Learning, And Ecosystem Modeling, Yanjun Yang

Theses and Dissertations--Plant and Soil Sciences

Climate change is projected to continue and accelerate significantly in the future if global greenhouse gas emissions are not curbed. Previous studies have shown that crop growth and production in agroecosystems are primarily determined by the weather conditions over the growing season. Crop phenology represents one of the most critical indicators in determining crop yield and adjusting the adaptation of crops to climate change. It provides essential information for monitoring and modeling crop growth dynamics and productivity. Therefore, understanding and quantifying the impacts of climate change on crop phenology and then agricultural production is crucial to formulate feasible climatic adaptation …