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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 …

Incorporation Of Summer Annual Mixtures Into Grazing Systems In Kentucky, Kelly Marie Mercier

Theses and Dissertations--Plant and Soil Sciences

Utilizing summer annual grass-legume forage mixtures has the potential to improve forage yield and nutritive characteristics, and/or animal performance during times when cool-season pasture growth is limited by high temperatures. Legumes can utilize atmospheric nitrogen, which can increase crude protein and forage digestibility in mixtures. As nitrogen application generally improves both the yield and nutritive characteristics of summer annual forages, but can have a negative effect on legume competitiveness, nitrogen fertilizer recommendations for legume-containing summer annual mixtures are not well established.

Two experiments were conducted to determine the feasibility of utilizing summer annual mixtures in Kentucky, USA. The first experiment …

Arthropod Resistant Tomatoes: Screening Tools, Yield And Nutritional Quality Of Interspecific Hybrids, Mohammad Hasan Salman Ali Dawood

Theses and Dissertations--Plant and Soil Sciences

Tomato (Solanum lycopersicum) is one of the most economically important vegetable crops grown around globe but is a host for numerous pests and pathogens. In the future, tomato breeders will have to focus on increasing fruit quantity and on enhancing pest resistance. Many accessions of the wild relative of tomato, S. habrochaites display high levels of resistance towards arthropods such as spider mites. The presence of the sesquiterpene hydrocarbon, 7-epi-zingiberene, found in S. habrochaites type IV trichomes has been associated with arthropod resistance. However, the presence of other compounds in its trichome secretions may also be related …

El Fríjol (Vigna Unguiculata Y Phaseolus Vulgaris) Como Alternativa Para La Diversificación Agrícola En Yopal, Casanare, Duber Alejandro Pinto Ramírez

Ingeniería Agronómica

El proyecto implementó una parcela demostrativa de 1.200 m², que incluyó manejo agronómico (plagas, enfermedades, arvenses, fertilización), la transformación de 2.270 kg del material vegetal en silo, y la comercialización del mismo con precio de referencia de 350 $ / kg, como alternativa de agronegocio a una Unidad Agrícola Familiar (UAF). Por otra parte, el objetivo del componente investigativo fue evaluar el efecto de tres densidades de siembra del fríjol rojo cuarentano (Phaseolus vulgaris) en la producción de grano, a través de la medición de parámetros de rendimiento; número de vainas por planta, número semillas por vaina, masa de 100 …

Biology And Management Of The Soybean Stem Borer, Dectes Texanus Leconte, In Kentucky, Izabela Gomes

Theses and Dissertations--Entomology

Dectes texanus LeConte (Coleoptera: Cerambycidae) is a longhorn beetle species endemic to eastern United States. Originally described as a pest of weeds from the family Asteraceae, D. texanus has expanded its host range and is found infesting the stems of soybeans, Glycine max (L.) through the southwestern and middle United States. Female D. texanus chews a hole in the epidermis of a petiole and oviposits on it. Then, the D. texanus larva depletes all the pith of the stem making a tunnel down to the base of the plant and girdle the stem about 5 cm above the …

Establecimiento De Un Sistema De Producción De 1 Hectárea De Maíz Amarillo (Zea Mays L.) Con Fines Comerciales En Popayán – Cauca, Liceth Viviana Tosne Chacón

Ingeniería Agronómica

Actualmente el maíz se ha convertido en uno de los cereales más utilizados para la alimentación animal y en una menor cantidad para el consumo humano (Zua Quetzal, 2014), encontrándose a nivel mundial según la Federación Nacional de Cultivadores de Cereales y Leguminosas (2018) como el primer cereal con mayor área cultivada. En Colombia, según datos de FENALCE (2018), el cultivo de maíz abarca un área de 210.241 hectáreas nacionales, postulándose como uno de los países con potencial para la producción, incentivando a los productores de diferentes regiones a instaurar la plantación con el fin de obtener ingresos económicos estables …

Sunflower Pollinators In South Dakota: An Evaluation Of Species Composition, Abundance And Influence On Yield, Mackenzie Mattern

Electronic Theses and Dissertations

In 2017 and 2018, South Dakota was the largest producer of sunflowers, Helianthus annuus L. (Asterales: Asteraceae) in the US, grossing approximately $178 million per year. In South Dakota, both confection and oilseed sunflower cultivars are grown. Despite breeding efforts to increase sunflower's ability to self-pollinate there is evidence that pollinator visitation results in increased sunflower yields. In addition, there is evidence that sunflower pollen is beneficial for pathogen resistance in various bee species, suggesting the importance of a mutualistic relationship between pollinators and sunflowers. In some areas, observed increases in sunflower yield is attributed to the presence of Apis …

Maximizing Ecosystem Services Provided To The New Oil Crop Brassica Carinata Through Landscape And Arthropod Diversity, Shane Stiles

Electronic Theses and Dissertations

Prairies, once spanning the Upper Midwest, have now largely been replaced by agriculture. The lack of resources available to pollinators in agricultural fields and the practices employed by farmers to maximize yield has led to a decline in insect and pollinator diversity. There is a need to better understand how ecosystem services provided by a diverse insect community scale to current farming practices as they relate to crop yield. We sought to explain how landscape heterogeneity relates to insect and pollinator diversity, as well as how insect diversity relates to crop yield across common farming practices. To evaluate how farming …

Effects Of Potassium Source And Rate On Yield, Quality, And Leaf Chemistry Of Dark And Burley Tobacco, And Residual Effects Of Soil K Levels, Andrea Brooke Keeney

Theses and Dissertations--Plant and Soil Sciences

Field trials were conducted in 2016, 2017 and 2018 with dark fire-cured, dark air-cured, and burley tobacco at Princeton, Murray and Lexington Kentucky. Tobacco variety used in 2016 was a low converter (LC) variety, varieties used in 2017 and 2018 were LC and higher converter (HC) varieties. Potassium sources used at all locations and in all years were potassium sulfate (K₂SO₄) and potassium chloride (KCl). Application rates used at all locations and in all years were 93, 186, 279 kg K ha^-1along with an untreated control that received no potassium. In all trials, tobacco …

Integrating Cover Crop Mixtures And No-Till For Sustainable Sweet Corn Production In The Northeast, Julie S. Fine

Masters Theses

Fall-planted forage radish (Raphanus sativus L. longipinnatus) cover crops have shown successful weed suppression and recycling of fall-captured nutrients. This research evaluated the nutrient cycling and weed suppressive benefits of forage radish cover crop mixtures to develop an integrated system for no-till sweet corn (Zea mays L. var rugosa) production that improves crop yield and soil health. Treatments included forage radish (FR), oats (Avena sativa L.) and forage radish (OFR), a mixture of peas (Pisum sativum subsp arvense L.), oats and forage radish (POFR), and no cover crop control (NCC). Subplots were assigned to …

The Effects Of Foliar Nutrient Applications On Split, Yield, And Internal Fruit Quality Of 'Wonderful' Pomegranate (Punica Granatum L.), John Matthew Chater

Master's Theses

Fruit split is the most important physiological disorder in pomegranate production, causing devastating crop losses worldwide. Foliar nutrient applications have been used experimentally to mitigate pomegranate fruit split but none have been conducted using the industry standard cultivar, Wonderful, and little is known about the effects of foliar nutrient applications on pomegranate. Additionally, investigations into putative health benefits of pomegranate fruit have increased interest in its production but limited evidence exists regarding effects of agricultural practices such as foliar fertilizer applications on internal fruit quality. ‘Wonderful’ pomegranate trees at 2 commercial orchards were treated with foliar applications of ZnSO_{4 …}

Physiological And Nutritional Characterization Of High Yield Soybean, Ryan John Van Roekel

Graduate Theses and Dissertations

Soybean [Glycine max (L.) Merr.] grain yields greater than three times the national average have been reported in yield contests. Characterization of soybean in a maximum yield environment is necessary to provide empirical data to support those yield claims and to provide an understanding of the physiological processes at that yield level. From 2011 to 2013, research characterized biomass and N accumulation rates, radiation use efficiency (RUE), leaf N dynamics, the rate of harvest index increase (dry matter allocation coefficient, DMAC), seedfill period (SFP), and grain yield components from Mr. Kip Cullers' contest fields and in small plots at the …

Switchgrass Yield And Quality With Multiple Fertilizer Applications And Harvest Dates, Thomas Clarkson Keene

Theses and Dissertations--Plant and Soil Sciences

Switchgrass (Panicum virgatum L.) is an important native warm-season grass for biomass and forage production in the U.S. This research determined the effect of fertilizer type (conventional, manure, and biosolids) and rate on switchgrass biomass yield and forage quality. Fertilizers were added at 0, 33, 67, 100, and 134 kg N ha^-1 on established stands of ‘Kanlow’ switchgrass in three northeastern Kentucky counties. Soils across sites ranged from recently cleared forestland (low pH, P, and K) to productive cropland (high pH, P and K). Stands were sampled for forage nutritive value in June, simulating a hay harvest. Nutritive …

The Effects Of Planting Techniques On Maize Grain Yield And Silage Production, Tyler D. Kaufman

Theses and Dissertations

This thesis is a comprehensive analysis of the effects of seed orientation, row direction and planting population on grain yield, kernel composition, and silage yield and composition. Producers are striving to increase profit by efficiently using their available land area to maximize crop production. However, little research is available testing the effect of seed orientation on grain or silage production. Quantifying the impacts of seed orientation and row direction on grain and silage is essential for maximum crop production. Dissemination of the results should benefit grain and silage producer.

Two experiments were conducted to evaluate the effects of manipulating seed …

Effects Of Leaflet Orientation And Root Morphology On Physiological Traits And Yield In Soybeans., Richard Dewayne Johnson

Doctoral Dissertations

Drought is the most important abiotic stress adversely affecting soybean (Glycine max (L.) Merr.) yield. Leaflet orientation has been shown to reduce leaflet temperatures and transpiration while root morphology has been related to slower wilting phenotypes. The objective of this study was to investigate effects of leaflet orientation and rooting morphology on whole plant transpiration, yield, water use efficiency, and other physiological traits in soybeans using grafting techniques, population lines, near-isogenic lines, and restrained leaf canopy experiments. Experiments were conducted in Knoxville, TN with additional yield trial plots at Springfield, Spring Hill, and Milan, TN. Data were collected on …

Using The Ceres-Maize Model To Create A Geographically Explicit Grid Based Estimate Of Corn Yield Under Climate Change Scenarios, Ryan Zachary Johnston

Graduate Theses and Dissertations

The CERES-Maize model was evaluated in its capacity to predict both regional maize yield and water use within the United States Department of Agriculture (USDA) Economic Research Service (ERS) Region 1 between the years 1997-2007. A grid based, geospatially explicit method was developed to express the various rainfed and irrigated maize cultivars grown across the region. Overall, the calibrated model compared well for both physiological and yield parameters, producing significant linear relationships (p

The calibrated and validated CERES-Maize model was used to predict potential evapotranspiration and yield under three IPCC weather scenarios for the year 2050 to evaluate crop production …

The Influence Of Chilling And Heat Accumulation On Bloom Timing, Bloom Length And Crop Yield In Almonds (Prunus Dulcis (Mill.)), Melanie M. Covert

Master's Theses

Almonds are one of the first commercial nut trees to bloom in early spring and thus are susceptible to temperature patterns prior to and during bloom which affect bloom timing, bloom length, pollination and nut set. Data used in this project include yearly dates of 90% bloom from 1996-2006, bloom length in days and final crop yields in pounds per tree for Nonpareil and Mission varieties. Data were collected from the University of California Cooperative Extension reports on the 1993-2006 Regional Almond Variety Trials in Butte, San Joaquin and Kern Counties. Temperature pattern models in the form of Chill Hours …

Stochastic Trends In Crop Yield Density Estimation, David I. Maradiaga

LSU Master's Theses

The search for improved methods of estimating crop yield density functions has been a theme of recurrent research interest in agricultural economics. Crop yield density functions are the statistical instrument that generates probability estimates of yield risk, and risk is an important decision variable in production agriculture. Recent research in crop yield density estimation suggests that yield probability estimates can be sensitive to the way yield data are filtered, and if true, then the search for an “adequate filter” is warranted. Such a quest is pursued in this study. It is proposed that unit-root tests can be used to identify …

The Effect Of Salinity Level Upon The Yield, Root Growth, And Water Extraction Of Contrasting Rooting Subpopulations Of Alfalfa (Medicago Sativa) Under Conditions Of Zero Leaching, Laura A. Vincent

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A major problem in irrigated agriculture in the Western U.S. is the gradual accumulation of salinity in the plant root zone. These nonuniformly saline soils contain increasing amounts of salinity with depth, and salt accumulation is accelerated in situations where leaching is minimized. Root growth and thus plant yield is limited in these soils due to decreased water uptake. We studied the root growth of two subpopulations of alfalfa differing in their ability to produce fibrous roots to determine if altering root morphology would increase plant yield and water extraction, in an irrigated saline soil.

Soil profiles for a control …

The Effect Of 2 Soil Fertility Levels On 5 Potato Varieties In Relation To Yield, Specific Gravity And Chipping Quality, Gayland D. Robison

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The potato enterprise is important in Utah as it provides a cash crop and also a means of diversifying and intensifying the operations on many irrigated farms. It is of particular value in the sections of the state that have a short growing season where other crops cannot feasibly be produced. The potato chip industry supplies a demand for large quantities of potatoes. The usage by this industry makes it a major factor in potato farming economy.

The making of chips originated over a hundred years ago as the result of an accident. A silver of potato fell into a …

The Yield And Thiamine, Riboflavin And Niacin Content Of Alfalfa Hay As Related To Fertilizer Treatment Of Soil, Rasik L. Pathak

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Alfalfa has long been recognized as an outstanding hay plant in terms of both yield and feeding value. It is high in digestible protein, minerals, and vitamins. Because of its long life it can be economically produced. It is of exceptional value in maintaining soil fertility by helping to control erosion, by improving the physical condition of the soil, and by accumulating large amounts of nitrogen.

The great importance of alfalfa growing in the United States is attested by its rapid and continued expansion. It is one of the most important forage crops and is grown on a greater acreage …