Plant Sciences Commons^™

The Effects Of Living Mulches On Organic, Reduced-Till Broccoli Growth And Management, Sarah Elizabeth Broughton

Masters Theses

Conservation tillage programs have been successfully implemented for many agronomic cropping systems, but adoption of reduced tillage for vegetable crops has been slow. As many conventionally managed conservation tillage programs rely on synthetic herbicides for clean cultivation, alternative methods must be devised to suppress weed pressure and reduce reliance on mechanical cultivation to aid in the development of reduced tillage programs for organic cropping system. Strip tillage is a reduced tillage method that is well suited to vegetable crop production, and the utilization of cover crops and living mulches between rows provides a viable weed management option for organic systems. …

Control Of Glyphosate Resistant Horseweed (Conyza Canadensis) With Saflufenacil And Tank-Mixture Partners., Brock Steven Waggoner

Masters Theses

Field and labratory studies were conducted to determine the efficacy of saflufenacil alone and with mixture partners for burndown. Field studies were conducted in 2009 and 2010 to evaluate saflufenacil in mixtures with glyphosate, glufosinate, or paraquat for control of glyphosate-resistant (GR) horseweed prior to planting cotton. Saflufenacil and saflufenacil mixtures were applied 7 days before planting (DBP). Saflufenacil at 25 and 50 g ai ha-1 in mixture with all three non-selective herbicides provided similar GR horseweed control when compared to the current standard of glyphosate plus dicamba. Control of GR horseweed was also not different at the 25 and …

Effect Of Mica Content On Surface Infiltration Of Soils In Northwestern Kern County, California, Steven Keyes Stakland

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A soils infiltration rate (IR) is the measured rate that soil is able to absorb water, either from precipitation or irrigation. A low IR can cause damage to crops if the necessary amount of water cannot penetrate to the plant roots in the time needed. The damage can be common in permanent plantings such as almond and pistachio orchards where regular tillage is avoided. This indicates a physical aspect to the problem because tillage increases IR. However, there is also an electrochemical side to infiltration problems because certain calcium surfactant treatments can increase IR. Various other methods have been used …

A Characterization Of Maine Blueberry Growers In 2010, Anya Rose

Electronic Theses and Dissertations

A survey was sent to 343 lowbush blueberry growers in Maine with a response rate of 29%. Growers were asked questions about their management practices, pesticide use, priorities, decision-making influences, and beliefs about pesticide safety. Respondents categorized themselves into one of four categories: Integrated Pest Management (IPM), Conventional, Organic, and No-Spray. Analyses were conducted to examine factors that were linked to these four categories. A major goal of this study was to determine differences and similarities between growers of different management styles, and to define each category by the practices and beliefs of its members. Toxicity ratings were also calculated …

Investigating Cold Hardiness And Management Practices Of Warm-Season Putting Green Species In The Transition Zone, John M. Kauffman

Doctoral Dissertations

Warm-season turf species are becoming increasingly popular for putting green use in the transition zone. Ultradwarf bermudagrass (Cynodon dactylon (L.)  C. transvaalensis Burtt-Davy) is the prevalent warm-season putting green species, but seashore paspalum (Paspalum vaginatum Swartz) and ‘Diamond’ zoysiagrass [Zoysia matrella (L.) Merr.] may also be grown in the transition zone. Warm-season species are susceptible to winter injury and may require different management regimes than cool-season species. Therefore, the objectives of this research were to assess the impacts of various management practices on warm-season putting green species and characterize the physiological basis for differences in freeze tolerance of various …

Effects Of No-Tillage On Crop Yields And Net Returns Across The United States, Dustin Kevin Toliver

Masters Theses

Farmers are always looking for ways to increase yields and profits and no-tillage may be a way to achieve this goal. However, a comprehensive study of the performance of no-tillage yields relative to conventional tillage yields and their net returns is lacking. This study evaluated the potential factors that influence differences in conventional tillage and no-tillage yields and net returns as explained by such factors as time, crop, precipitation, soil texture and geographic region. Data were collected from 442 paired tillage experiments growing corn, soybeans, cotton, oats, wheat and sorghum published in three refereed journals. Data were evaluated using a …

Taxonomy, Biogeography And Pest Status Of Marmara Sp. In Northern Mexico And California Citrus Production, Paul Semet

Master's Theses

A novel lepidopteran sex pheromone lure which was thought to be species-specific to the citrus pest Marmara gulosa (Lepidoptera: Gracillariidae) Guillén (McElfresh et al. 2009) has attracted male moths exhibiting two distinct morphologies. The morphological features examined were the sclerotized parts that make up the male genitalia; which include the valvular lobes, costal lobes, cucullar lobes, and the aedeagus. The sclerotized parts were methodically dissected and mounted on microscope slides. Digital images captured of the slide-mounted specimens proved to be inconsistent with the illustrations provided in the original Marmara gulosa species description (Guillén et al. 2001).

The morphologies of all …

Influence Of Irrigation Strategies On The Photosynthetic Rate Of Syrah, Daniel Michael Rodrigues

Master's Theses

Regulated deficit irrigation (RDI) is a common and useful practice for water conservation and improving grape quality. To attain better grape characteristics and wine quality, a substantial degree of irrigation stress is intentionally allowed to occur during the first part of berry formation and can continue until later into veraison. Understanding the effects of deficit irrigation on photosynthetic rates could be helpful in determining at what degree and duration a grower should perform this irrigation practice. The focus of this study was to determine the effects of using differing degrees of RDI in a vineyard located in Paso Robles, California …

Environmental Variables Influencing The Severity Of Pierce's Disease In California Grapevines, Christopher James Boisseranc

Master's Theses

This project was designed to correlate environmental variables with the development of Pierce’s Disease (PD), an infection caused by the gram negative bacterium Xylella fastidiosa (Xf), in grapes (Hopkins et al. 2002). PD is one of the most difficult crop pathogens to manage because it is vectored by insects and its continued presence in the vine is usually fatal. PD is influenced by the interaction of host, disease and vector, and probably many other environmental variables. The general objective was to study and identify the most important variables involved in the expression of Pierce’s Disease.

Over a two year period, …

Lifespan Of Prokaryote Model Organism Escherichia Coli K-12, Hyrum Gillespie

Undergraduate Honors Capstone Projects

Bacteria are amazingly resilient organisms, in that they have evolved and adapted to the many extreme environments of Earth (from salt, to pH, to temperature extremes etc.). The bacterial lifespan and death rates are as important as its growth rates in these extreme environments. Bacteria would be useful to determine the effects of age on single cells, but because bacteria reproduce asexually by binary cell fission (clonal replication), calculating the lifespan has proven elusive. Without the determination of a lifespan, age studies using bacteria have limited application. Further, it has been proposed that organisms whose somatic cell line is not …

Classification And Fertility Of Soils In The Big South Fork National River And Recreation Area Based On Landscape Position And Geology, Ryan H. Blair

Masters Theses

The Big South Fork National River and Recreation Area encompasses more than 50,585 hectares (125,000 acres) of the Cumberland Plateau along the border of Tennessee and Kentucky. Highly dissected and steep terrain have made accessibility to much of the park limited, thus little work has been done to investigate the formation of these soils. Seven native soil profiles were selected for chemical and physical analysis representing Pennsylvanian-aged acidic sandstone and shale geology and landforms. The objectives of this study included the characterization of selected native profiles by physical and chemical analysis, as well as classification using US Soil Taxonomy, to …

Effects Of Trinexapac-Ethyl And Winter Overseeding On The Morphological Characteristics And Traffic Tolerance Of Bermudagrass Cultivars, William D. Haselbauer

Masters Theses

Common bermudagrass [Cynodon dactylon (L.) Pers.] and hybrid bermudagrass [C. dactylon (L.) Pers. X C. transvaalensis Burtt-Davy] are some of the most common turfgrasses used on athletic fields. Subsequently, the traffic tolerance of commercially available cultivars and the effects of trinexapac-ethyl (TE) on bermudagrass athletic fields with or without perennial ryegrass are often limited. A two year study at the University of Tennessee was conducted under simulated athletic field traffic to evaluate the performance of bermudagrass cultivars as affected by TE and overseeding. Bermudagrass cultivars evaluated were Tifway, Riviera, Patriot, and Celebration. TE treatments consisted of an untreated …

Optimizing The Physical And Nutritional Environment Of Unleached Root-Zones, Curtis B. Adams

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Unleached root-zones represent an environmental ideal by eliminating wasteful leaching of nutrients and water. NASA grows plants in space in unleached root-zones, incorporating polymer-coated fertilizer (PCF) into a ceramic media (Turface or Profile). However, lack of growth productivity in space has led to the need for research to improve the nutritional and physical environment of the root-zone, which is the objective of this research. PCF types are diverse in release characteristics and the effects of temperature and substrate water content have not been well characterized. In spite of widespread use, studies on chemical properties and applied studies to verify soil …

The Influence Of Collective Action And Policy In The Development Of Local Food Systems, Lori Porreca

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The modern global agrifood system has had significant negative impacts on consumers and producers. This has precipitated the rise of local food systems that are purported to improve the health and livelihoods of consumers and producers. High expectations have led to significant public and private resources dedicated to the development of local food systems. Despite this, there has been little systematic research exploring the social and institutional conditions that facilitate or frustrate local food system development.

Using a comparative case study approach, this study explored the ways local structural conditions, collective action, food system policies, and the political context affect …

Comparative Performance Of Fluorometry And High Performance Liquid Chromatography In The Detection Of Aflatoxin M1 In Two Commercial Cheeses, Gustavo Peña

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Aflatoxin M1 (AFM₁) is frequently found in milk and dairy products. It is a metabolite formed in cows from aflatoxin B1 (AFB₁), contained in animal feeds. In cheese production AFM₁ distributes between curds and whey. In this study, cows were fed 64 µg/AFB₁/d for the high treatment, and 5 µg/AFB₁/d for the low treatment, to obtain milk contaminated with AFM1 over the 0.5 µg/L and under 0.05 µg/L restrictions, respectively. Cheese was manufactured with milk contaminated with AFM₁ at 0.8 and 0.03 ìg/kg by the higher and lower …

Evapotranspiration Of Kentucky Bluegrass, Lynda L. Fenton

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Rapid population growth in arid regions of the western US is placing increased demand on water resources. Variability in precipitation and common occurrence of drought have promoted scrutiny of water use in urban lawns and gardens. However, few reliable measurements of water use of these landscapes exist. Quantifying the amount of water used vs. required by landscapes such as turfgrass would allow significant water conservation. Evapotranspiration (ET) is affected by biophysical factors such as: available energy, turbulent mixing, saturation deficit, soil water, and stomatal conductance. In order to simulate the water use by turfgrass, the relative importance of these processes …

Phylloplanins: Novel Antifungal Proteins On Plant Leaf Surfaces, Ryan William Shepherd

University of Kentucky Doctoral Dissertations

Secreted surface proteins are an innate immune defense component employed by animals to inhibit invading microbes. Surface proteins have not been documented in plants, even though the aerial leaf surface, or phylloplane, is a major site of pathogen ingress. We have discovered novel proteins, termed phylloplanins, which accumulate on leaf surfaces of Nicotiana tabacum, and we have isolated the gene Phylloplanin that is unique in gene databases. Natural and E. coli-expressed phylloplanins inhibit spore germination and limit leaf infection by the oomycete pathogen Peronospora tabacina.

We investigated the site of phylloplanin biosynthesis using biochemical techniques. These techniques …

Efecto Del Biofertilizante Agroplux® Sobre La Producción De Biomasa Y La Calidad De Un Cultivo De Pasto De Corte Maralfalfa Pennisetum Sp. En El Municipio De Montenegro Quindío, Maria Fernanda Escudero Sierra, Juan Manuel Hernandez Patiño

Zootecnia

El estudio se realizó en la finca el Mirador ubicada en el municipio de Montenegro, Quindío, con el fin de analizar el efecto que tiene el Agroplux® asociado con bovinaza sobre el pasto Maralfalfa (Pennisetum sp.), utilizando tres tratamientos denominados: Testigo (TO), Agroplux® (AP) y Agroplux® + Bovinaza (APB). Cada uno de los tratamientos tuvo cuatro parcelas, divididas a su vez en cuatro subparcelas para los cuatro cortes realizados a los días 40, 60, 80 y 100. Para esto diariamente se realizó el conteo de hojas, macollos, medición de altura de las plantas y se tomó la temperatura máxima y …

Grazing Evaluation Of A Novel Endophyte Tall Fescue Developed For The Upper Transition Zone, Jennifer Michelle Johnson

University of Kentucky Doctoral Dissertations

A wild-type endophyte (Neotyphodium coenophialum [(Morgan-Jones & Gams) Glen Bacon & Hanlin]) that infects tall fescue [Lolium arundinaceum (Schreb.) Darbysh. = Schedonorous arundinaceum (Schreb.) Dumort.] imparts tolerances to moisture, heat, and grazing stresses, but also produces ergot alkaloids that adversely affect performance and physiology of cattle. Novel endophytes, developed by AgResearch Ltd. NZ, can sustain fescue persistence and productivity, but do not produce toxic ergot alkaloids. University of Kentucky Plant Breeder, T. D. Phillips Ph.D, developed a tall fescue experimental population (KYFA9301) for the upper transition zone. A 2-yr grazing experiment was conducted with steers to evaluate steer …

Agronomic Performance Of Five Varieties Of Forage Grasses Inroduced In Carmen Pampa, Province Of Nor Yungas, La Paz, Joel Eliseo Bautista Vargas

Theses and Dissertations

This study was done with the objective of evaluating the agronomic performance of five varieties of forage grasses introduced to the community of Carmen Pampa in the province of Nor Yungas, La Paz from 2005-2006. The average temperature during the study was 11.93ºC and the average precipitation was 801.75 mm. The trial was done with a design of randomized blocks having five species and six repetitions. The species studied were: Panicum virgatum, Sorghastrum nutans, Andropogon gerardii, Tripsacum dactyloides, and Eragrostis curvula. Variables evaluated were: plant height (cm), coverage (%), number of plants, bunches of florets, and dry matter yield (kg/ha). …