Index Catalog // ScholarsArchive@OSU

Continued exploration of barley genotype contribution to beer flavor and the application of this knowledge to variety development and release

Creator:: Morrissy, Campbell P.
Abstract:: Investigation on barley genotype contribution to beer flavor is a relatively new area of research but has interest from members of the malting barley supply chain. This body of work builds upon previous studies by approaching it from new angles that further supports the malting and brewing industries’ interests around...
Resource Type:: Dissertation

Mechanisms of Organic Matter Accumulation and Feedbacks on Pore Space in Ferralsols/Oxisols Containing High Carbon Stocks

Creator:: Martinez, Pedro
Abstract:: Deeply weathered soils in tropical rainforests and savannas are classified as Ferralsols according to the World References Bases for Soil Resources (WRB). Ferralsols are most nearly akin to the Oxisols order defined in the US Soil Taxonomy. The acidity, low cation exchange capacity, and strong phosphorus retention by the oxidic...
Resource Type:: Dissertation

The Impact of Freeze-Thaw Cycles to the Physical and Biogeochemical Properties of Alaskan Permafrost Soils

Creator:: Rooney, Erin C.
Abstract:: Arctic warming is exposing thawing permafrost to repeated freeze-thaw, a disruptive process that can alter soil biogeochemistry and physical structure. To investigate the impact of permafrost exposure to freeze-thaw, soil response was tested across three scales: 2.5 cm³ aggregates, a forested hillslope, and two sites at contrasting latitudes. XCT imaging...
Resource Type:: Dissertation

Spring Nitrogen, Plant Growth Regulator, and Defoliation Effects on Seed Production in Two Fine Fescue (Festuca rubra L.) Species

Creator:: Anderson, Nicole P.
Abstract:: One important cool-season perennial grass seed crop grown in Oregon is fine fescue (Festuca rubra L.). Open-field burning has been used for many decades to manage pests, cycle nutrients, and stabilize yield, in fine fescue seed fields, especially as stands age. Legislative restrictions currently limit open-field burning to 6,070 hectares...
Resource Type:: Dissertation

Identifying Quantitative Trait Loci for Resistance Against Stripe Rust and Septoria tritici blotch in Soft White Winter Wheat

Creator:: Cobertera, David
Abstract:: Stripe rust (Puccinia striiformis f. sp. tritici) and Septoria tritici blotch (Zymoseptoria tritici) are a constant and significant threat to wheat production, significantly reducing wheat quality and yield. Wheat is responsible for 20% of the world’s human calorie intake, and wheat production must increase to supply the demand of the...
Resource Type:: Dissertation

Topometric Analysis for High-throughput Phenotyping of Seed Shattering in Perennial Ryegrass (Lolium perenne L.)

Creator:: Tubbs, Travis B.
Abstract:: Seed shattering is a constraint to improvement of seed yield in Lolium perenne L. and as a result, seed retention is an essential trait for this valuable crop. Field studies were conducted near Corvallis, OR in two years (2017-2018 and 2018-2019) to identify genetic variation for seed retention and to...
Resource Type:: Dissertation

Seed Development in Orchardgrass (Dactylis glomerata L.) in Relation to Plant Growth Regulators and Spring Nitrogen

Creator:: Morad, Mohammed M.
Abstract:: Orchardgrass (Dactylis glomerata L.) is an important seed crop, but unlike other cool-season perennial grass seed crops such as perennial ryegrass (Lolium perenne L.) and tall fescue [Schedonorus arundinaceus (Schreb.) Dumort.], seed yields have not increased over time so there is considerable room for improvement. Research suggests that plant growth...
Resource Type:: Dissertation

Impact of Dairy Manure Digestate on Microbial Activities in Soil

Creator:: Waggoner, Ashley L
Abstract:: Amendments and fertilizers applied to optimize crop production and improve soil health also supply inputs of soil organic matter (SOM) and nutrients that affect soil microorganisms. In the dairy-intensive Pacific Northwest, dairy manure is stored as slurry mixtures until conditions are appropriate for soil application. During storage, the manure begins...
Resource Type:: Dissertation

Detrital Influences on Soil Carbon Stabilization in Wet Temperate Forest Soils

Creator:: Pierson, Derek N.
Abstract:: Soils, with their potential to store and stabilize carbon (C), are an essential resource for sustaining forest productivity, as well as for efforts to reduce atmospheric C concentrations. Protecting existing soil C and harnessing the sequestration potential of our soils require an improved understanding of the processes through which soil...
Resource Type:: Dissertation

Genome Wide Association Mapping for Abiotic and Biotic Stresses in Barley (Hordeum vulgare L.) Using Diverse Arrays of Doubled Haploids Derived From Intercrossing Exotic and Adapted Germplasm

Creator:: Hernandez, Javier
Abstract:: The following dissertation consists of six sections: a general introduction, three manuscripts, a general conclusion, and an overall bibliography. The three manuscripts report on: (1) identifying genetic interactions in diverse germplasm developed during introgression of a major gene conferring resistance to stem rust (Puccinia graminis f. sp. tritici), (2) mapping...
Resource Type:: Dissertation

Wheat (Triticum aestivum) Kernel Polymers as Breeding Targets for Improved End-Use Quality

Creator:: Trittinger, Susanne
Abstract:: Wheat is a staple food crop with many applications. The composition and quantity of major and minor flour components greatly influence functional dough properties, processing quality, and end-use suitability. Seven to 15% of the weight of wheat flour is protein and the gluten proteins comprise 80-85% of that. The gluten...
Resource Type:: Dissertation

Modern Wheat Breeding: Next Generation Sequencing and CRISPR Transformation

Creator:: Brandt, Kali M.
Abstract:: Wheat (Tritium aestivum) is an extremely important crop worldwide. It accounts for almost one quarter of the calories consumed each day by more than one third of the world’s population, and is grown over more land area than any other crop. Wheat breeding programs constantly strive to increase or maintain...
Resource Type:: Dissertation

Decomposition of Brassicaceae Residue in the Willamette Valley

Creator:: Berry, Pete A.
Abstract:: An important inoculum source of Leptosphaeria maculans and L. biglobosa (syn Plenodomus spp.), the pathogens that cause black leg in Brassicaceae crops, is infected plant residues. The general acceptance of conservation tillage in the Willamette Valley, Oregon, USA, has enabled a build-up in the amount of residue on or near...
Resource Type:: Dissertation

Brassicaceae Seed Persistence and Dormancy in the Willamette Valley

Creator:: Flick, Gabriel D.
Abstract:: Producers in the Willamette Valley of Oregon are interested in growing canola as a rotational crop in grass seed and cereal rotations. Many other Brassicaceae seed crops also are produced within the valley. Concerns of seed persistence and volunteer contamination of Brassicaceae seed crops prompted the investigation of seed persistence...
Resource Type:: Dissertation

Diversity and Activity of Microbial Extracellular Peptidases in Soil

Creator:: Nguyen, Trang T. H.
Abstract:: Soil nitrogen exists largely as organic matter, including plant liter, dead animal matter, and microbial necromass. About 90% of soil organic nitrogen is proteinaceous material that is too large for plants and microorganisms to assimilate directly. Protein depolymerization therefore plays a critical role in mobilizing this organic source of nitrogen,...
Resource Type:: Dissertation

Using Algal Biomass as a Fertilizer

Creator:: Cappellazzi, Shannon B.
Abstract:: Algae can be used in a variety of wastewater systems to capture nutrients while fixing carbon dioxide from the atmosphere. I conducted field trials at three locations in Oregon with both corn and potato crops to assess the agronomic value and environmental impact of using the resulting algal biomass as...
Resource Type:: Dissertation

Mineral Surfaces as Agents of Environmental Proteolysis: Mechanisms and Controls

Creator:: Chacon, Stephany S.
Abstract:: The bottleneck in the turnover of soil organic matter (SOM) is the conversion of large molecular compounds into smaller compounds that can be transported through a cell membrane of a microbe for processing. Once inside the cell, organic compounds can be converted into biomass or be respired. The microbial depolymerization...
Resource Type:: Dissertation

Long-term Impacts of Nitrogen Fertilizer, Tillage and Crop Residue on Soil and Plant Nutrients in Winter Wheat Cropping Systems Under Dryland Conditions

Creator:: Shiwakoti, Santosh
Abstract:: Agricultural practices influence the nutrient dynamics of soil and plants, which may take more than a decade to be expressed in the drylands. The nutrient supplying capacity of soil is a crucial component of sustainable agriculture, and hence, this study can play an important role in policy making for the...
Resource Type:: Dissertation

Merging Field Work with Machine Learning : Exploring Andic Soil Development in the Cascade Range

Creator:: Osterloh, Kristopher Richard
Abstract:: Andic soils (aka Andisols) have unique properties that are important to society. For soil scientists, the genesis and taxonomy of Andisols is often confused because they can form in both volcanic and non-volcanic material. This dissertation seeks to address such confusion by looking at andic soil development in the Cascade...
Resource Type:: Dissertation

Scaling, ash-driven bistability, and other agents of soilscape genesis discovered while digitally mapping soils of the Blue Mountains, Oregon

Creator:: Almquist, Vance Warner
Abstract:: This dissertation reports on four related, though separate projects. The first project details the process of carrying out a digitally augmented soil mapping (DSM) effort alongside an ongoing survey in Oregon's Ochoco National Forest (ONF) using a Random Forest algorithm. The second chapter describes a initial soil survey in Oregon's...
Resource Type:: Dissertation

Breeding qualitative and quantitative traits for potatoes in the Columbia Basin

Creator:: Graebner, Ryan C.
Abstract:: The cultivated potato (Solanum tuberosum L.) is one of the world’s most important staple crops, ranked fourth after maize, rice, and wheat. While the potato’s success is due largely to its high yield, it also benefits from its broad global acceptance, and its ability to be used by the consumer...
Resource Type:: Dissertation

Effect of Plant Growth Regulator and Irrigation on Physiological and Harvest Maturity of Red Clover in Relation to Seed Quality

Creator:: Angsumalee, Duangporn
Abstract:: Red clover (Trifolium pratense L.) seed yield can be affected by plant growth regulators (PGR) and irrigation; however, the effects of these factors on physiological maturity (PM), harvest maturity (HM), and seed quality are unknown. The objectives of this study were to: 1) determine how irrigation and trinexapac-ethyl (TE, a...
Resource Type:: Dissertation

Developing Flavorful and Sustainable Barley (Hordeum vulgare L.): Integrating Malting Quality and Barley Contributions to Beer Flavor within the Framework of Facultative Growth Habit

Creator:: Herb, Dustin Walker
Abstract:: This dissertation consists of a general introduction, three manuscripts, and general conclusions. The research integrates research on (1) the effects of barley genetics and production environment on the contribution of barley to beer flavor, (2) the effects of degree of malt modification on barley contributions to beer flavor and (3)...
Resource Type:: Dissertation

An Examination of Factors Controlling the Activity of Ammonia- and Nitrite-oxidizers in Diverse Soils

Creator:: Giguere, Andrew T.
Abstract:: Nitrification is a critical step in the global nitrogen cycle involving the biological oxidation of ammonia (NH₃) to nitrite (NO₂⁻ ) and then to nitrate (NO₃⁻). The first step in nitrification is carried out by NH₃-oxidizing bacteria (AOB) and archaea (AOA), and the second by NO₂⁻-oxidizing bacteria (NOB). In addition...
Resource Type:: Dissertation

Physiological, Chemical and Genetic Studies in Meadowfoam (Limnanthes alba)

Creator:: Zhang, Jun
Abstract:: Meadowfoam (Limnanthes alba) is an oilseed crop with unique chemical characteristics. The ability to identify physiological maturity (PM) and harvest maturity HM of the crop would permit timely harvest of high quality seeds. However, changes of oil contents, fatty acid profile and glucosinolate contents, as well as seed quality during...
Resource Type:: Dissertation

Response of Roughstalk Bluegrass (Poa trivialis L.) to Waterlogging Stress

Creator:: Liu, Mingyang
Abstract:: Roughstalk bluegrass (Poa trivialis L.) (RB) is a weed species that increased very quickly in grass seed production fields of the Willamette Valley. The invasion of RB in grass seed crops often occurs in waterlogged soils. In waterlogged areas, RB exhibited better competitiveness and had greater population densities than other...
Resource Type:: Dissertation

Identifying QTLs for Sustainability Traits (Disease Resistance and Malt Quality) in the Facultative/Winter 6-rowed Elite Malting Barley GWAS Panel, the TCAP FAC-WIN6

Creator:: Belcher, Araby Ruth
Abstract:: This dissertation consists of a general introduction, three research manuscripts, and general conclusions regarding the mapping of quantitative trait loci (QTLs) for sustainability traits in the Triticeae Coordinated Agricultural Project (TCAP) facultative/winter 6-rowed elite malting barley genome-wide association studies (GWAS) mapping panel, the TCAP FAC-WIN6. The first research manuscript, a...
Resource Type:: Dissertation

Modeling Survival of Soilborne Phytophthora spp. and Characterizing Microbial Communities in Response to Soil Solarization and Biocontrol Amendment in Container Nursery Beds

Creator:: Funahashi, Fumiaki
Abstract:: In horticultural nurseries for container-grown plants, production and sales have been threatened by the presence of a quarantined plant pathogen, Phytophthora ramorum (causal agent of sudden oak death). Infested nursery beds are an important source of P. ramorum, which can initiate disease through movement with surface water to infect roots...
Resource Type:: Dissertation

Cultural controls for suppressing Phytophthora cinnamomi root rot of blueberry

Creator:: Yeo, John R.
Abstract:: Phytophthora cinnamomi is a soilborne pathogen that causes root rot disease of highbush blueberry (Vaccinium corymbosum L.). When new installations of susceptible blueberry cultivars are infected with P. cinnamomi, plants often fail to grow significant new tissue, greatly reducing yields over the life of the planting. Chemical fungicides are available...
Resource Type:: Dissertation

Multi-location analysis for the identification of quantitative trait loci underlying disease resistance against Cephalosporium gramineum and Puccinia striiformis f. sp. tritici by linkage mapping in wheat (Triticum aestivum L.)

Creator:: Vazquez, Maria Dolores
Abstract:: Wheat (Triticum aestivum L.) is one of the major crops produced in the U.S. Pacific Northwest, a region known for its wheat production for international export. Wheat production in the region is threatened by diseases such as Cephalosporium stripe and stripe rust. Cephalosporium stripe is a vascular wilt disease of...
Resource Type:: Dissertation

Hybridization between imidazolinone-resistant wheat (Triticum aestivum L.) and jointed goatgrass (Aegilops cylindrical Host.) and selection pressure impacts on proportion of resistance alleles

Creator:: Martins, Bianca Asssis Barbosa
Abstract:: Imazamox-resistant wheat (Clearfield®) cultivars carry the Imi1 gene, which confers resistance to the imidazolinone (IMI) herbicide imazamox. Imazamox provides selective control of jointed goatgrass and other weeds in IMI-resistant wheat. Imi1 gene flow between IMI-resistant wheat and jointed goatgrass may occur via hybridization and backcross events. In 2009 and 2010,...
Resource Type:: Dissertation

Assessing the role of reactive metal species in soil organic matter cycling using chemical imaging

Creator:: Keiluweit, Marco
Abstract:: Intimate associations with reactive metal species permanently protect soil organic matter (SOM) from microbial access and oxidation, contributing to the build-up of organic carbon (C) stocks in soils. It is increasingly recognized, however, that such associations can be reversible and that reactive metal species might even facilitate the oxidation of...
Resource Type:: Dissertation

Bioherbicide use of plant defensive compounds in meadowfoam seed meal

Creator:: Intanon, Suphannika
Abstract:: Meadowfoam (Limnanthes alba Hartw. ex Benth) seed meal (MSM), a by-product of meadowfoam oil extraction, has a plant defensive compound known as glucosinolate glucolimnanthin (GLN). Myrosinase enzymes present in soil microbes and meadowfoam seeds can convert GLN to glucosinolate breakdown products (GBPs), which demonstrate herbicidal activity and have the potential...
Resource Type:: Dissertation

Seed quality and plant establishment studies of seashore paspalum (Paspalum vaginatum Sw.)

Creator:: Baker, Stanley D.
Abstract:: Seashore paspalum (Paspalum vaginatum Sw.) is an important warm-season perennial turfgrass, known for its tolerance to salinity. Turfgrass is used for homes, municipalities, sod farms, resorts, and sports fields. Seashore paspalum has historically been planted in sub-tropical and tropical climates because of its heat tolerance. Seashore paspalum could become an...
Resource Type:: Dissertation

Nitrogen and dry matter relationships for winter wheats produced in western Oregon

Creator:: Locke, Kerry A.
Resource Type:: Dissertation

Water relations in red and white clover seed crops

Creator:: Oliva, Ruben N.
Abstract:: Both red (Trifolium pratense L.) and white (Trifolium repens L.) clover seed yields can be highly variable and low in western Oregon. The objectives of this study were to: i) determine crop water requirements and supplemental irrigation timing, and ii) quantify the effects of soil and water status on inflorescence...
Resource Type:: Dissertation

Genetics of partial incompatibility and improvement of haploid production in Hordeum vulgare L. x H. bulbosum L. crosses

Creator:: Chen, Fu-chiang and Chen, Fuqiang
Abstract:: The production of barley (Hordeum vulgare L.) haploids by crossing with H. bulbosum is a widely used tool in breeding and genetics. Certain barley genotypes have low seed set in this interspecific cross, a phenomenon known as partial incompatibility. Haploid production efficiency and gamete sampling are important issues with the...
Resource Type:: Dissertation

Effect of density, proportion, and spatial arrangement on the competition of winter wheat and Italian ryegrass (Lolium multiflorum Lam)

Creator:: Hashem, Abul, 1956-
Resource Type:: Dissertation

Differential sensitivity of Italian ryegrass and rice cultivars to fenoxaprop

Creator:: Hassan, Gul
Resource Type:: Dissertation

Hydrological consequences of two native shrubs in semi-arid Senegal : patterns, processes, concepts and methods

Creator:: Kizito, Fred
Abstract:: Water availability is a critical limiting element in semi-arid ecosystem productivity and presents particular challenges in Sahelian countries such as Senegal. The landscapes are characterized by the presence of two common semi-arid shrubs (Piliostigma reticulatum and Guiera senegalensis), both of which may be important hydraulic regulators in these water-limited ecosystems....
Resource Type:: Dissertation

Geostatistical applications to salinity mapping and simulated reclamation

Creator:: Al-Taher, Mohamad A.
Abstract:: Geostatistical methods were used to find efficient and accurate means for salinity assessment using regionalized random variables and limited sampling. The random variables selected, sodium absorption ratio (SAR), electrical conductivity (EC), and clay content were measured on samples taken over an area of fifteen square miles. Ordinary kriging and co-kriging...
Resource Type:: Dissertation

Effect of nitrogen and water stresses during tillering and grain- filling in wheat

Creator:: Ashraf, Muhammad, 1952-
Abstract:: The CERES-Wheat Crop Growth and Development model treats temperature, nitrogen and water stresses as limiting factors. For each day the model calculates a stress index for temperature, N and water, compares the magnitude of the indices, and then adjusts the calculated daily potential growth using the index of the most...
Resource Type:: Dissertation

Water and solute transport : modeling and application to water conservation in layered soil

Creator:: Mohammed, Fareed H. A. N.
Abstract:: Sandy soils are among the least productive soils because of their inability to store adequate water for plant growth. Their high percolation rate not only allows water to move quickly beyond the root zone, but also washes nutrients below the reach of plant roots. High evaporation occurs from the soil...
Resource Type:: Dissertation

Duration and rate of grain filling and subsequent grain protein content in selected winter wheat populations

Creator:: Mou, Beiquan
Abstract:: The lack of information regarding the inheritance of the duration and rate of grain filling, and the possible relationship between grain fill and grain protein content in wheat prompted this study. Early maturing Chinese cultivars, 'AI Feng 2' and 'CB 83-52', and late maturing cultivars adapted to Oregon, 'Stephens' and...
Resource Type:: Dissertation

The effect of preplant nitrogen fertilization and soil temperature on biological nitrogen fixation and yield of alfalfa (Medicago sativa L.)

Creator:: Shuler, Philip E.
Abstract:: The usefulness of preplant nitrogen (N) in establishing alfalfa in colder production areas has not been well characterized. This study was conducted to determine the effect of preplant N and soil temperature on yield, percent N derived from biological nitrogen fixation (PBNF), and shoot N concentration in alfalfa (Medicago sativa...
Resource Type:: Dissertation

Rattail fescue (Vulpia myuros) control in Italian ryegrass (Lolium multiflorum) grown for seed

Creator:: Reyes, Carlos C.
Abstract:: Italian ryegrass growth and production from positionally selective applications and sublethal rates of a nonselective herbicide were compared to growth and production when treated with diuron applied preemergence as a broadcast treatment and safened by activated carbon applied over the crop row. In the positionally selective treatments, herbicide spray was...
Resource Type:: Dissertation