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MIXING DYNAMICS OF INHOMOGENEOUS ANISOTROPIC TURBULENCE : AN EXPERIMENTAL STUDY OF SINGLE-STREAM SHEAR LAYERS
No full textThesis (Ph.D.)--Michigan State University. Mechanical Engineering - Doctor of Philosophy, 2025Shear-driven mixing flows are canonical configurations of both scientific and engineering relevance, occurring widely in natural and industrial flow systems. Broadly classified into two-stream shear layers (TSSLs) and single-stream shear layers (SSSLs), the latter is often considered as a limiting case of the former. While TSSLs have been extensively studied, SSSLs remain comparatively underexplored, particularly through high-resolution volumetric measurements capable of resolving their full turbulence dynamics. This dissertation addresses this gap by employing high-speed optical flow diagnostics in a custom-built, high- Reynolds-number water tunnel facility (Re\u3c4 up to 481700) to investigate SSSL development from separation to self-similarity, including detailed characterization of the upstream wall boundary layer (BL) to establish initial conditions. High-speed 4D Particle Tracking Velocimetry (PTV) and planar 2D Particle Image Velocimetry (PIV) are used to capture velocity fields in both the BL and the SSSL.Sparse time-resolved PTV data are assimilated using an adaptive Gaussian weighting method to reconstruct instantaneous velocity fields and higher-order turbulence quantities, including turbulent kinetic energy (TKE) budget terms. The resulting mean fields matched the accuracy of leading data assimilation techniques and enabled quantification of SSSL growth, coherent structure dynamics, and TKE distribution. Phase-averaged analysis revealed localized zones of energy production and dissipation with distinct spatial separation between their peaks.A comparative analysis of SSSL mean growth revealed inconsistencies in reported rates. This study shows that the initial boundary-layer Reynolds number governs these variations, leading to a unified empirical scaling that collapses growth rates, and extends to peak turbulent kinetic energy and Reynolds stress magnitudes, for both SSSLs and TSSLs.Lagrangian particle tracks are used to quantify single- and pair-particle dispersion, intermittency, and velocity-gradient tensor dynamics in the SSSL. Dispersion statistics revealed ballistic short-time behavior, with near-homogeneous turbulence in the core region and increasing anisotropy and external intermittency toward the outer edge. Invariant dynamics showed preferential evolution toward stable focus\u2013stretching topologies, while joint enstrophy\u2013strain statistics highlighted spatially varying intermittency, most homogeneous at the center and amplified near the edges. Conditional scaling indicated non-unity enstrophy\u2013 strain relations, weaker amplification than in isotropic turbulence, and local isotropy within the core.The Eulerian data is further analyzed using a novel Mori\u2013Zwanzig Modal Decomposition (MZMD) framework that incorporates past-state memory effects to model periodic coherent motions in the SSSL. MZMD outperformed standard Dynamic Mode Decomposition in capturing nonlinear dynamics and coherent oscillations, and it shows strong potential for modeling higher-order effects, such as production, dissipation, and modal energy-transfer coupling.The study concludes with a discussion of facility modifications enabling variable-viscosity SSSL experiments involving fluid streams of widely differing viscosities. It also provides practical guidelines for fluorescent particle and dye selection and refractive-index matching. During the multi-fluid mixing assessments, ultra-low-cost fluorescent particles were developed for simultaneous velocimetry and concentration measurements via Laser-Induced Fluorescence. Furthermore, a single-camera imaging strategy is proposed to extract both velocity and scalar fields from a single intensity map.In conclusion, this dissertation presents a comprehensive experimental characterization of single-stream shear layer growth, and associated coherent motions further examined through data-driven modeling of their periodic dynamics. It reconciles growth-rate scaling across free-shear layers, thereby advancing the prospects for improved computational modeling. Moreover, it offers new insights into the Lagrangian dynamics of inhomogeneous anisotropic turbulence. Collectively, the methodological, physical, and practical contributions of this work position it as a valuable reference for future investigations of complex turbulent flows in both fundamental and applied contexts.Description based on online resource. Title from PDF t.p. (Michigan State University Fedora Repository, viewed ).Includes bibliographical references
Gamma-Ray Spectroscopy of 46Ar and Linear Polarization Analysis with Fast Beams
No full textThesis (Ph.D.)--Michigan State University. Physics - Doctor of Philosophy, 2025The isotope 46Ar is a key transition point along the N=28 shell evolution from doubly magic 48Ca to the highly collective 42Si. Despite the justified attention this isotope has received, much of the 46Ar energy level structure beyond the 2+1 state is either controversial or unknown. This work presents a study of the 46Ar level scheme via gamma-ray spectroscopy, where the nucleus was produced using the one-proton pickup reaction 12C(45Cl, 46Ar + \u3b3)X. This experiment utilized the state-of-the-art gamma-ray tracking detector GRETINA (Gamma-Ray Energy Tracking In-beam Nuclear Array) and was conducted at the National Superconducting Laboratory (NSCL). A total of 39 gamma ray transitions were identified in the 46Ar spectrum. Gamma-gamma coincidences and gamma-ray intensities were used to assemble a 46Ar level scheme. A total of 18 excited states were identified in 46Ar, and 28 gamma-ray transitions were placed in the level scheme.Additionally, the production reaction was chosen because it was previously demonstrated to populate excited states with significant alignment. This alignment makes angular distribution and linear polarization measurements possible, which are used to determine or constrain the gamma-ray multipolarity and parity, respectively. This work discusses the unique challenges of performing linear polarization measurements with fast beam data (v/c 73 0.15) and details the analysis methods used to overcome these challenges. This work presents, for the first time, statistically significant linear polarization results from the analysis of fast beam data. Angular distributions are also analyzed to determine or constrain gamma-ray transition multipolarities. Linear polarization and angular distribution measurements were benchmarked with the well-known 2+1 \u2192 0+1 transition, and were used to directly confirm the suspected 4+ spin-parity of the 46Ar state near 3865 keV.Description based on online resource. Title from PDF t.p. (Michigan State University Fedora Repository, viewed ).Includes bibliographical references
ECONOMIC ANALYSIS OF CONTROVERSIES IN THE U.S. AGRI-FOOD SYSTEM : MISINFORMATION, FOREIGN FARMLAND OWNERSHIP, AND FOOD PRICE INFLATION
No full textThesis (Ph.D.)--Michigan State University. Agricultural, Food and Resource Economics - Doctor of Philosophy, 2025This dissertation explores three enduring and controversial challenges in the U.S. agri-food system: misinformation, foreign farmland ownership, and food price inflation. Essay one examines how misinformation about food biotechnology affects consumers\u2019 food choices and proposes evidence-based countermeasures. Essay two investigates the drivers behind state-level legislative restrictions on foreign farmland ownership. Essay three analyzes how supply chain positioning relates to corporate financial performance amid recent economic shocks. Collectively, these studies offer a holistic view of the interdependent economic agents shaping the U.S. agri-food system and carry broad implications for its resilience and governance. Given that technological advancement, geopolitical conflicts, and inflationary pressures are persistent features of the global landscape, this dissertation provides a valuable foundation for future work to help agribusiness leaders, consumers, and policymakers make better-informed decisions during uncertain times.The first essay examines the effect of misinformation about genetically modified food on consumer demand and policy attitudes, and tests the effectiveness of pre-bunking and debunking mitigation strategies. While food biotechnology can contribute to agricultural sustainability and food security, prevalent misinformation risks enlarging the public-scientist knowledge gap and precluding the adoption of potentially beneficial technologies. Using data from a sample of 1,270 U.S. consumers, I find that exposure to misinformation has a significant effect on consumers\u2019 food choices and policy attitudes. I also find that pre-bunking is an effective mitigating strategy, while debunking by itself is not sufficient. This suggests that preemptively warning consumers about misinformation and the tactics used to spread it is more effective than merely correcting the misinformation afterwards. The second essay investigates the drivers of state-level legislative restrictions on foreign farmland ownership, a topic actively debated in the Congress and state legislatures. Foreign holdings of U.S. agricultural land have raised national and food security concerns, reflected in the growing amount of state legislative actions that seek to restrict foreign holdings of U.S. agricultural land in recent years. While there has not been clear evidence of the negative impacts of such foreign holdings, these restrictive legislations could lead to unintended economic consequences. Using uniquely constructed legislator- and state-level data, I find that while protecting state agricultural assets is part of the consideration, these state legislative actions are also responding to national security concerns raised by China-related incidents in recent years. The third essay explores how corporate profitability across U.S. agri-food supply chain segments responded to major economic shocks. U.S. retail food prices have surged rapidly to historic highs following COVID-19 and the Russia-Ukraine conflict, raising concerns about profit-driven inflation, although the evidence remains mixed. Because higher food prices can reduce affordability, identifying the key drivers of inflation is essential for designing effective policies. Using firm-level panel data of publicly listed companies from 2015 to 2024, I find heterogeneity in profitability across segments. I also find limited evidence of profit-driven food price inflation in the post-shock periods; overall, gross profits increased, but margins remained stable. Combined with analysis of corporate filings, the results suggest that rising costs and fiscal policies, rather than inflated markups, may be more important drivers of accelerating retail food prices.Description based on online resource. Title from PDF t.p. (Michigan State University Fedora Repository, viewed ).Includes bibliographical references
OPTIMIZING MILK FAT SYNTHESIS IN DAIRY COWS THROUGH DE NOVO AND PREFORMED FATTY ACID SUPPLY
No full textThesis (M.S.)--Michigan State University. Animal Science - Master of Science, 2025In mammary epithelial cells, milk fatty acids (FA) originate from two sources. De novo FA, including 4- to 14-carbon and part of 16-carbon, are synthesized in the mammary gland, whereas preformed FA, including >16-carbon and part of 16-carbon, originate from dietary sources or lipid mobilization. De novo FA synthesis relies primarily on acetate and beta-hydroxybutyrate (BHB) generated in the rumen during carbohydrate fermentation, as well as BHB produced in the liver. Both sources contribute to 16-carbon FA, with their relative contribution influenced by dietary fat levels, FA profile, and available rumen fermentative substrates. Importantly, both sources are interdependent: de novo and preformed FA stimulate the synthesis of one another. The first study evaluates the effect of replacing dietary starch with sugar on milk yield and composition in high-producing dairy cows. Changing the dietary carbohydrate source may alter fermentation, leading to increased acetate and butyrate concentrations and thereby increasing substrate supply for de novo FA synthesis. The second study determines the effect of high-oleic soybean oil (HOSBO) inclusion on milk yield and composition in high-producing dairy cows. The study aims to evaluate optimal dietary inclusion of HOSBO in high-producing dairy cows. Dietary HOSBO inclusion might increase energy density and improve mammary uptake of preformed FA. The results of these two studies emphasize the importance of optimizing the substrate supply of de novo and preformed FA sources to improve milk fat yield. Additionally, these findings will provide dairy farmers, consultants, and nutritionists with science-based tools to improve herd performance and profitability in an increasingly demanding production environment.Description based on online resource. Title from PDF t.p. (Michigan State University Fedora Repository, viewed ).Includes bibliographical references
IMMERSIVE VIRTUAL REALITY EXERCISE TO IMPROVE DEPRESSIVE SYMPTOMS IN YOUNG ADULTS WITH AUTISM SPECTRUM DISORDER
No full textThesis (Ph.D.)--Michigan State University. Kinesiology - Doctor of Philosophy, 2025Depression is a common co-occurring issue for people with Autism Spectrum Disorder (ASD), and it often emerges or intensifies in young adulthood, a time of heightened social expectations and diminished support structures. Traditional interventions for improving mood, such as cognitive behavioral therapy and pharmacotherapy, have had limited reach and retention for autistic populations due to differences in social communication, sensory processing, and intrinsic motivation. Physical activity (PA) may offer a low-stress, engaging, and enjoyable pathway to both better fitness and mood. Immersive virtual reality (VR) exercise can provide compelling and structured experiences that help address sensory and motivational barriers to PA. Self-Determination Theory (SDT) posits that supporting basic psychological needs for autonomy, competence, and relatedness is key to cultivating intrinsic motivation, which is itself essential to long-term exercise adherence and mental-health benefits. This dissertation sought to investigate whether VR-based exercise can improve depressive symptoms and motivation among young adults with ASD. It does so by presenting evidence from three linked studies that together examined the feasibility, acceptability, and preliminary efficacy of a technology-mediated, theory-driven exercise intervention for mental health. Study 1 is a systematic review and meta-synthesis of eight empirical studies published to date in which people with a range of developmental disabilities engaged in immersive VR exergames. I found that exergames improved physical activity, locomotor performance, attention, and emotion regulation, and I identified critical gaps in the existing literature, including the need for more robust experimental designs and larger sample sizes. Study 2 is a six-week randomized controlled trial (RCT) with a neurotypical sample (N = 30; ages 18-24; VR exercise n = 15, control n = 15) that tested the immediate feasibility and acceptability of an immersive VR boxing exercise intervention in the Supernatural application and was designed to inform power and feasibility calculations for Study 3. Results showed that the VR exercise group exhibited reductions in depressive symptoms on the Patient Health Questionnaire-9 (PHQ-9) at the end of the trial with medium effect sizes (t(28) = -2.16, p = .039, g = 0.65). Study 3 was a four-week mixed-methods RCT that further developed and tested the VR exercise intervention among young adults with ASD (N = 20; ages 18-27; VR exercise n = 6, control n = 8, 6 dropouts). Quantitative results showed a significant improvement in depressive symptoms (t(28) = \u20132.16, p = .039, g = 0.87) and strong behavioral engagement (session adherence = 94%, total exercise 48 255 min [4 h 15 min], ~35 min/session, mean %HR 48 73%, punch accuracy \u2191 68 \u2192 84%). Qualitative data suggested that the intervention supported users\u2019 basic psychological needs by fostering feelings of autonomy, competence, and relatedness during interactions with the virtual coach. These studies collectively demonstrate the feasibility, acceptability, and preliminary efficacy of immersive VR exercise in enhancing depression and promoting motivation for mental health among young adults on the spectrum. Taken together, this dissertation supports the use of a technology-mediated, theory-driven, and highly immersive exercise intervention to promote mental health in ASD, and it provides novel evidence for exercise to improve depression and PA among young adults with ASD. By demonstrating that VR exercise can be an enjoyable and scalable approach to addressing mental health and PA disparities among neurodivergent populations, this body of work provides a critical first step towards long-term intervention trials.Description based on online resource. Title from PDF t.p. (Michigan State University Fedora Repository, viewed ).Includes bibliographical references
PRESUPPOSITION, COMPETITION, AND COHERENCE : A UNIFIED APPROACH TO PARTIAL RESOLUTION AND DE RE PRESUPPOSITION
No full textThesis (Ph.D.)--Michigan State University. Linguistics - Doctor of Philosophy, 2025This dissertation investigates two underexplored puzzles in presupposition: partial resolution and de re presuppositions. The former challenges the canonical felicity condition by showing that certain presupposition triggers remain felicitous even when their presuppositions are only partially entailed by the context. The latter involves cases where presuppositions embedded under attitude verbs are interpreted with respect to information entailed in the common ground, independent of the attitude holder\u2019s beliefs. Focusing on a range of Mandarin Chinese triggers, ye (\u4e5f \u2018also\u2019), you (\u53c8 \u2018again\u2019), reng (\u4ecd \u2018still\u2019), jiu (\u5c31 \u2018only\u2019), zhidao (\u77e5\u9053 \u2018know\u2019), buzai (\u4e0d\u518d \u2018no longer\u2019), and kaishi (\u5f00\u59cb \u2018start\u2019), this study reveals a systematic correlation: triggers that permit partial resolution also allow de re interpretations. To account for this, I propose an Alternative Competition framework governed by a ranked set of pragmatic constraints: Internal Coherence >> Felicity Presupposition >> Maximize Presupposition. This framework explains why presuppositional forms may be preferred even in contexts that do not fully support their presuppositions, namely, to maintain discourse consistency and avoid contradictions. By examining the interplay between presuppositional meaning, structural alternatives, and pragmatic constraints, this study offers a novel perspective on how speakers strategically optimize their linguistic choices. To account for de re presuppositions, I introduce the Weak Commitment Assumption, whereby presuppositions are locally accommodated within the agent\u2019s attitude contexts without requiring belief attribution. I argue that de re interpretations of various expressions do not arise from a single mechanism such as substitution or movement, but rather through distinct strategies. Additionally, an exploration of postsuppositional phenomena, particularly in Mandarin A-TOO B-TOO and A-AGAIN B-AGAIN constructions, reveals how Alternative Competition shapes discourse-level interpretation.Description based on online resource. Title from PDF t.p. (Michigan State University Fedora Repository, viewed ).Includes bibliographical references
COMPARATIVE ANALYSIS OF DRYING METHODS FOR BLUEBERRIES : EFFECTS ON PHYSIOCHEMICAL ATTRIBUTES
No full textThesis (M.S.)--Michigan State University. Food Science - Master of Science, 2025Blueberries (Vaccinium corymbosum) are renowned for their high content of bioactive compounds, particularly anthocyanins and antioxidants, which contribute to their health-promoting properties. This study evaluated the effects of three drying methods\u2014freeze drying, infrared (IR) drying, and hot air drying\u2014on the retention of these compounds and the physical quality of blueberries. Chemical analyses quantified total phenolics, anthocyanins, and antioxidant capacity, while physical analyses assessed color (L*, a*, b*). Results showed that freeze-drying had best-preserved anthocyanins and antioxidant activity, maintaining superior color quality with minimal decreases in a and b values. In contrast, IR drying caused the greatest losses in bioactive compounds and color degradation, while hot air drying produced intermediate results. Overall, freeze drying demonstrated the least degradation of key quality attributes, highlighting its effectiveness for preserving bioactive compounds in blueberries. These findings provide valuable insights for the food processing industry in optimizing drying techniques to retain nutritional and sensory quality in value-added blueberry products.Description based on online resource. Title from PDF t.p. (Michigan State University Fedora Repository, viewed ).Includes bibliographical references
RIGID POLYURETHANE AND POLYISOCYANURATE FOAMS MADE WITH LIQUID LIGNIN POLYOLS
Get PDFThesis (M.S.)--Michigan State University. Forestry - Master of Science, 2025Lignin is a complex, abundant natural polymer that has attracted significant attention as an alternative to petroleum-based polyols in rigid polyurethane foams, owing to its aromatic structure, high functionality, and high hydroxyl (OH) value. However, the limited reactivity of its sterically hindered phenolic hydroxyl groups towards isocyanates has limited the utilization of solid lignin to approximately 50% polyol substitution, with a noticeable decline in properties beyond that point. Oxyalkylation with cyclic carbonates has emerged as a green and effective method for improving lignin reactivity by converting the phenolic hydroxyl groups into more reactive aliphatic OH groups. This thesis focuses on the development of rigid polyurethane and polyisocyanurate foams using oxypropylated lignin polyols. First, a simple yet novel method was employed to increase the hydroxyl value of lignin polyols by the in-situ generation of propylene glycol. Then, rigid polyurethane (PU) foams were produced by fully replacing petroleum-based polyols with synthesized lignin polyols. The developed lignin polyols had very high reactivity, necessitating the addition of a delayed-action catalyst to control foaming. The lignin-based foams also met most of the standard specifications for type II spray-applied rigid cellular polyurethane thermal insulation and had superior mechanical properties compared to the foam made with conventional fossil fuel-based polyol. The biobased foams, however, had slightly lower thermal stability due to the presence of propylene glycol and other oligomers of propylene carbonate. Finally, urethane-modified polyisocyanurate (PUR/PIR) foams were prepared with oxypropylated lignin polyols. These foams exhibited improved flame retardancy, with significantly shorter burn times than the control, even without the addition of flame retardant, and showed less shrinkage compared to the petrochemical-based foams.Description based on online resource. Title from PDF t.p. (Michigan State University Fedora Repository, viewed ).Includes bibliographical references
CONSTRAINING ELECTRON-CAPTURE RATES USING (He) REACTION IN INVERSE KINEMATICS
Get PDFThesis (Ph.D.)--Michigan State University. Physics - Doctor of Philosophy, 2025This thesis describes the use of the reaction in inverse kinematics with rare-isotope beams to constrain electron-capture rates, which are important for accurately simulating the heating and cooling processes in neutron star crusts. Electron-capture rates are calculated from Gamow-Teller (GT) strengths, which can be extracted experimentally in a model-independent way using charge-exchange reactions at intermediate energies. Following a successful pilot study with the and reactions in inverse kinematics using the Active-Target Time Projection Chamber with the S800 spectrometer at the Facility of Rare Isotope Beam, a second experiment was performed to investigate the and reactions using an identical setup.The nuclei and are located in or near the "island of inversion," a region where shell evolution leads to the inversion of the and shells. These nuclei play an important role in understanding the Urca mechanism in neutron star crusts, where rapid cycles between electron capture and decay result in significant cooling due to strong neutrino emission. This thesis presents the experimental setup, data analysis, and results for the extracted GT strengths from these reactions. GT strengths were extracted for one state in the reaction and two states in the reaction. The results provide evidence that the assumption of a closed-shell structure is invalid for and . Although the uncertainties in the extracted GT strengths are large, there is reasonable agreement with shell-model calculations that include contributions from both the - and -shell configurations.In addition to the experimental work, weak interaction rates and their impact on neutron star crusts were examined for nuclei in the and shells, for which precise shell-model calculations are already established. Neutron star crust simulations utilized three different sets of weak interaction rates: (1) rates derived solely from Quasiparticle Random Phase Approximation (QRPA) calculations, (2) shell-model rates for and shell nuclei, combined with QRPA rates for all other nuclei, and (3) experimental data for and shells when available, supplemented by shell-model calculations, with QRPA rates used for all other nuclei. The inclusion of experimental data for weak interaction rates leads to a suppression of both heating and cooling effects, and the results align more closely with the rates from shell-model calculations than with those from QRPA calculations.The results from this work underscore the importance of precise weak interaction rates for realistic neutron star modeling and demonstrate the effectiveness of the reaction in inverse kinematics as a tool for extracting essential nuclear data.Description based on online resource. Title from PDF t.p. (Michigan State University Fedora Repository, viewed ).Includes bibliographical references
ADVANCING INTEGRATED FIELD CROP DISEASE MANAGEMENT THROUGH EPIDEMIOLOGICAL INSIGHTS INTO PHYLLACHORA MAYDIS AND SCLEROTINIA SCLEROTIORUM
Get PDFThesis (Ph.D.)--Michigan State University. Plant Pathology - Doctor of Philosophy, 2025Due to the humid continental climate of Michigan, field crops suffer from a plethora of fungal pathogens causing infections of roots, stems, foliage and reproductive structures. In 2022, corn, soybean, potatoes and dry beans accounted for 6.2 million acres in Michigan, approximately 65% of the state\u2019s agricultural production land. Phyllachora maydis is a fungal pathogen of corn that is emerging in the region, causing tar spot of corn. Sclerotinia sclerotiorum is a long-established fungal pathogen across many economically important hosts produced in Michigan, including leguminous and vegetable crops. Both P. maydis and S. sclerotiorum are highly influenced by their environment, resulting in erratic and unpredictable year-to-year economic impacts due to the prevailing weather conditions regionally. Therefore, the focus of this dissertation was to improve our understanding of these pathogens\u2019 interactions with their environment to create new disease management recommendations and tools. In chapter 1, I provide a review of the current literature on P. maydis and S. sclerotiorum biology, infection strategy and the management of their respective diseases. I also briefly discuss the use of spore traps in plant pathogen epidemiology research and disease management, as well as the history and current state of predictive modeling for white mold management. In chapter 2, I conducted a field trial to address key questions about cultural management of tar spot of corn. This study established that neither high nor low nitrogen application rate influences tar spot development and that low planting density increases tar spot severity. However, an economic analysis of the optimal planting density revealed that increasing planting density to reduce tar spot severity was not a viable management strategy. Therefore, other disease management strategies, such as planting partially resistant hybrids, should be employed rather than altering established agronomic practices. In chapter 3, I used a previously developed P. maydis qPCR assay, Burkard and rotating-arm spore traps to quantify spore capture in tar spot-infested fields. Using data collected from 6 different environments, logistic regression modeling showed that spore release was negatively related to maximum precipitation rate, minimum and mean temperature, and maximum relative humidity, and positively related to minimum wind speed. The best performing logistic regression model used mean temperature and maximum relative humidity to predict the capture of P. maydis spores, achieving a balanced accuracy of 85%. As the spore traps were used in this study, they were not able to detect spores prior to the onset of visible disease symptoms but were able to detect spores prior to tar spot incidence reaching 100%. With future improvement of spore trap deployment and qPCR sensitivity, Michigan farmers could benefit from an early tar spot warning system to aid in expediting disease management decision making. In chapter 4, I used on-site weather monitoring systems and supervised machine learning to predict S. sclerotiorum apothecia presence in irrigated environments. Apothecia monitoring was conducted in soybean, dry bean and potato fields representing 20 site-years to develop a multi-crop apothecia prediction model. Decision tree (DT) models performed best, with an accuracy of 77% when developed using gridded weather data and 89% after incorporating soil weather data collected on-site. Interpretability of models did not have to be sacrificed to achieve a high prediction accuracy, as the DT developed using untransformed features performed comparably to the DT developed using principal components. Through this study, a robust framework for developing multi-crop S. sclerotiorum apothecia prediction models was demonstrated, but future model validation will be required to assess the value of the prediction models for SSR disease control. Lastly, in chapter 5, I discuss the conclusions and impacts from the work described herein. Overall, these studies contribute to the current understanding of P. maydis and S. sclerotiorum epidemiology and the management of their associated diseases on Michigan field crops.Description based on online resource. Title from PDF t.p. (Michigan State University Fedora Repository, viewed ).Includes bibliographical references