Digital Commons Network^™

Anaerobic Soil Disinfestation As A Non-Chemical Management Option Against Fungi And Heterotrophic Bacteria In Organic Sweetpotato Production, Meredith Tucker

All Theses

North Carolina is the largest producer of sweetpotatoes in the United States, with South Carolina increasing farming acreage to 2,501 in 2022 compared to 1,300 in 2017. Growers producing conventional and organic sweetpotatoes are equally challenged with managing fungal pathogens due to fungicide resistance or fungicides being unavailable due to environmental regulations, leading many to shift to growing organic crops. Anaerobic soil disinfestation (ASD) is a non-chemical pre-plant management option that uses a carbon amendment, irrigation, and plasticulture to establish an anaerobic environment in soils, killing soil microbes. A greenhouse study was conducted to assess ASD on fungal pathogens and …

Chromosome Evolution Model Reveals Hidden Variation In Karyotype-Driven Speciation In Ferns, Thomas Buchloh

All Theses

Because karyotype change commonly generates reproductive isolation between diverging species, rapid karyotype evolution, like that seen in plants, may increase the total rate of diversification. However, few studies have investigated this predicted relationship. Tests of this prediction have identified a positive correlation between the rate of karyotype change (specifically whole genome duplications) and diversification, but tests have been restricted to relatively small and young clades. Fortunately, novel macroevolutionary models have recently become available to investigate patterns of karyotype evolution in large phylogenies, providing new opportunity to investigate variation in karyotype driven diversification. Ferns are one of the most karyotype rich …

The Impacts Of Management Practices On Industrial Hemp Chemistry, Physiology, And Microbiome Ecology., Allison Marie Rietman

Electronic Theses and Dissertations

Agroecology incorporates ecology and agronomy to inform crop management. Industrial hemp (Cannabis sativa L.) is a prime system to investigate agroecological questions because it has only recently been authorized for commercial cultivation and its sensitivity to biotic and abiotic stressors is unresolved. Here, I investigate how some conventional management choices, including the application of fungicide, plastic mulch, and irrigation, impact the physiology, chemistry, and microbial ecology of industrial hemp. Overall, I found that industrial hemp can be both resilient and resistant to these stressors, an important development for the industry. In Chapter II, I tested the impacts of fungicide application …

Investigation Into Mycorrhizae Associated With Native Venus' Flytrap Root Tissue, Anna Carnaggio

Electronic Theses and Dissertations

Dionaea muscipula, a plant commonly known as the Venus' flytrap, is found native to the southeast corner of North Carolina and the northeast corner of South Carolina. Several populations of native Venus' flytraps are known to exist in the nutrient-poor peat bog conditions in and around Lewis Ocean Bay Heritage Preserve (LOBHP) in Northeastern South Carolina. Anthropogenic pressures in Horry County, specifically surrounding LOBHP, have resulted in a loss of habitat for several native and endangered species. As a result, conservation efforts are focused on relocating native Venus' flytraps into adjacent habitats to ensure survival. This is only a temporary …

Understanding The Impact Of Fall Armyworm (Spodoptera Frugiperda) Feeding, And Drought Stress On Drought-Tolerant And Drought-Resistant Soybean (Glycine Max)., Adriana G. Peissel

Crop, Soil and Environmental Sciences Undergraduate Honors Theses

Drought and insect herbivory are two major stressors on high-value crops like soybean (Glycine max). However, few studies have explored how these stressors interact, despite their presence in tandem under field conditions. We investigated how drought stress and fall armyworm (Spodoptera frugiperda) caterpillar herbivory impact Magellan (drought-tolerant) and Blackhawk (drought-susceptible) soybean cultivars. The soybean plants were subject to four treatment groups (1. Drought 2. Herbivory 3. Drought + Herbivory 4. Well-Watered) during a treatment period of 7 days in a greenhouse. We then measured plant height, physiological traits, trichome density, soil moisture, and larval mass gain. …

Identification And Characterization Of Intermediate Phenotypes To Decipher Genetic Architecture Of Stalk Lodging Resistance In Maize (Zea Mays L.), Bharath Kunduru

All Dissertations

Maize is a key contributor to global food security and incurs severe yield losses due to stalk lodging, the permanent displacement of plants from an upright growth habit due to mechanical damage to the stem (stalk). Stalk lodging resistance, an indicator of the stalk ability to resist lodging, is a complex trait and determined by several structural, geometric, and material properties of stalks, collectively referred to as intermediate phenotypes, whose identity and genetic framework are poorly understood. Therefore, progress in resolving the genetic architecture of stalk lodging resistance was impeded by a lack of standardized phenotyping methodologies and a poor …

Understanding The Genetic And Metabolic Underpinnings Of Complex Traits In C4 Grasses, Manwinder Singh Brar

All Dissertations

Maize (Zea mays L.) and sorghum (Sorghum bicolor (L.) Moench) are two important cereal crops cultivated worldwide for food, animal feed, and industrial products. Productivity of these crops is significantly impacted by various biotic and abiotic stresses, such as diseases, insect pests, drought, salinity, and heat. Among factors influencing crop performance under stress, the regulation of leaf longevity plays a critical role in determining yield. Leaf senescence is a highly regulated process essential for nutrient remobilization through the degradation of cellular components in aging leaves, but premature or accelerated senescence reduces photosynthetic efficiency and yield. Staygreen, a phenotype …

Investigate The Use Of Nucleic Acids As Pesticides To Manage Major Pests And Pathogens Of Crops In South Carolina, Prasanna Valavanur Shekar

All Dissertations

The sugarcane aphid (SCA, Melanaphis sorghi), first discovered on grain sorghum in late 2013, has gradually become a major insect pest of sorghum. It inflicts significant damage to the crop year after year, causing millions of dollars in losses throughout the sorghum-producing regions of the United States. Similarly, Armillaria root rot—also referred to as oak root rot—is a major cause of decline in peach (Prunus persica) production in the southeastern United States. This disease is caused by Armillaria mellea and Armillaria tabescens. Current management practices for controlling M. sorghi include the use of synthetic pesticides, resistant varieties, and regular scouting. …

Repair Through Recycling, Emma Murdock, Karl Aspelund

Senior Honors Projects

Repair Through Recycling is an instructional website I developed to encourage people to mend their garments rather than throw them away.I see this as a way to help address the growing issue of textile waste, where millions of garments are discarded each year. Many of these are made from synthetic materials that do not break down, contributing significantly to environmental pollution. This project features step-by-step instructional videos I created to teach the basics of mending, skills that are no longer commonly taught. These tutorials cover foundational techniques such as threading a needle and hand-stitching torn seams. The website also includes …

Long-Term Cropping System And Manure Effects On Soil Health Parameters And Associated Soil-Borne Pathogens, Joyce Mutai, Beth Medvecky, Steven J. Vanek, John Ojiem, Peter Bolo, Job Kihara, Steven J. Fonte

All Peer-Reviewed Publications

Soil-borne pathogens reduce the performance of key food crops in sub-Saharan Africa. Diversified cropping and nutrient management can enhance soil and plant health, limiting pathogen damage. To examine how management and soil health changes influence soil-borne pathogens, we leveraged an 18-year field trial in western Kenya, evaluating cropping systems typical of smallholder farms. We considered three cropping systems and two organic matter management strategies: continuous maize monocrop (M–M), Tephrosia in rotation with maize (T–M), maize intercropped with soybean (M–S), application or not of farmyard manure, and retention or removal of crop residues. We assessed soil physical and chemical properties and …

Improved Management Strategies For Botrytis Fruit Rot, Macrophomina Root Rot, And Verticillium Wilt In California Strawberry Production, Joseph A. Ramirez

Master's Theses

Strawberry production in California is limited by plant diseases such as Macrophomina root rot (MRR) caused by Macrophomina phaseolina, Verticillium wilt (VW) caused by Verticillium dahliae, and Botrytis fruit rot (BFR) caused by Botrytis cinerea. Current disease management strategies are compromised due to fumigant regulations or ineffective disease management practices. This thesis investigated methods to potentially improve the management of these three diseases. Two host plant resistance evaluations for MRR and VW were conducted for the 2022-2023 and 2023-2024 growing seasons. Sixty-three strawberry genotypes were screened in both years. All plants were exposed to the pathogen via artificial …

Optimizing Nutrient Recycling To Achieve Zero–Discharge Management For Controlled Environment Agriculture, Noah James Langenfeld

All Graduate Theses and Dissertations, Fall 2023 to Present

Controlled environment agriculture (CEA) allows for human control of one or more environmental factors affecting crop production. Optimizing nutrient management in such systems allows for translation and predictions of sustainable management strategies in the field. These systems will be used to supply fresh food as public and private space agencies are planning to send humans to the Moon and Mars in the near future. Food resupply becomes increasingly difficult as the distance from Earth increases. Plants can be grown off-Earth as a food source, but their growth must be carefully managed to ensure long-term sustainability. I describe a model used …

Effects Of Plant Biostimulants On Onion Growth And Production Under Greenhouse And Field Conditions, Prakriti Nepal

All Graduate Theses and Dissertations, Fall 2023 to Present

The escalating impact of climate change on agricultural production underscores the need to investigate sustainable crop enhancement methods. This research explores the use of plant biostimulants to grow onion (Allium cepa L.) under varying environmental conditions. In the initial germination and greenhouse screening, seven biostimulants were tested on ‘Vaquero’ onion seeds: three bacterial products (Continuum, Spectrum DS, and Tribus Original), two mycorrhizal products (Mighty Mycorrhizae and Myco Apply), one seaweed extract product (Seaweed), and one product containing humic acid (Huma Pro 16). Mighty Mycorrhizae, Continuum, and Myco Apply supported faster germination, while seeds treated with Spectrum and Seaweed took …

Seeding Rate, Planting Date, And Herbicides For Dormant Seeded Safflower In Utah, Rodney Daniel Nelson

All Graduate Theses and Dissertations, Fall 2023 to Present

Dryland crop production in the Intermountain West is largely limited by the amount of precipitation received. Increasing dryland safflower (Carthamus tinctorius L.) production yields in a semi-arid climate is possible with a dormant planting but is not well understood. A two-year (2020-22) project was designed to gain an understanding of the effects of variety, seeding rate, and planting date, on dormant seeded safflower. Chemical weed control options for safflower were also evaluated. One study, conducted at three Utah State University research farms near Blue Creek, Clarkston, and Kaysville, UT, evaluated four varieties, S-208, S-333, 7325 and Hybrid-446, seeded at …

Novel Horticultural Approaches For Reduced Gravity And Controlled Environment Agriculture, Sarah Elizabeth Schreck

All Graduate Theses and Dissertations, Fall 2023 to Present

On July 16, 1969, Apollo 11 achieved the first successful moon landing, marking a significant milestone in human space exploration. This historic moment effectively ended the space race between the United States and the Soviet Union, and since then, countries around the world have continued to advance their space programs. While the space race has evolved, the next major challenge lies in sending humans to Mars—a journey that could take 6 to 9 months each way, presenting numerous challenges, including the critical issue of nutritional sustainment for the crew.

This thesis addresses key aspects of a broader effort to support …

Plant Diversity Dynamics Over Space And Time In A Warming Arctic, Mariana García Criado, Isla H. Myers-Smith, Anne D. Bjorkman, Sarah C. Elmendorf, Signe Normand, Peter Aastrup, Rien Aerts, Juha M. Alatalo, Lander Baeten, Robert G. Björk, Mats P. Björkman, Noémie Boulanger‐Lapointe, Ethan E. Butler, Elisabeth J. Cooper, J. Hans C. Cornelissen, Gergana N. Daskalova, Belen Fadrique, Bruce C. Forbes, Greg H. R. Henry, Robert D. Hollister, Toke Thomas Høye, Ida Bomholt Dyrholm Jacobsen, Annika K. Jägerbrand, Ingibjörg S. Jónsdóttir, Elina Kaarlejärvi, Olga Khitun, Kari Klanderud, Tiina H. M. Kolari, Simone I. Lang, Nicolas Lecomte, Jonathan Lenoir, Petr Macek, Julie Messier, Anders Michelsen, Ulf Molau, Robert Muscarella, Marie-Louise Nielsen, Matteo Petit Bon, Eric Post, Katrine Raundrup, Riikka Rinnan, Christian Rixen, Ingvild Ryde, Josep M. Serra‐Diaz, Gabriela Schaepman‐Strub, Niels M. Schmidt, Franziska Schrodt, Sofie Sjögersten, Manuel J. Steinbauer, Lærke Stewart, Beate Strandberg, Anne Tolvanen, Craig E. Tweedie, Mark Vellend

Wildland Resources Faculty Publications

The Arctic is warming four times faster than the global average¹ and plant communities are responding through shifts in species abundance, composition and distribution^2,3,4. However, the direction and magnitude of local changes in plant diversity in the Arctic have not been quantified. Using a compilation of 42,234 records of 490 vascular plant species from 2,174 plots across the Arctic, here we quantified temporal changes in species richness and composition through repeat surveys between 1981 and 2022. We also identified the geographical, climatic and biotic drivers behind these changes. We found greater species richness …

Raíces Y Recuerdos: Plantas Ornamentales Para Entornos Saludables, Adriana Hernández Bustos, María Janeth Camargo Garzón, María Victoria Rojas Martínez, Segundo Leonardo Cortes López

Ciencias de la Salud

El reino vegetal es un universo lleno de vida, colores, texturas, aromas y beneficios que trascienden a través del tiempo. Es un aliado perfecto para el trabajo conjunto e intergeneracional; para este caso, las plantas no solo embellecen los paisajes y espacios, sino que tienen además el poder de mejorar nuestra calidad de vida, especialmente cuando se integran en actividades terapéuticas y sociales con personas mayores.

Investigating Silicon As A Candidate For Plant Synthetic Biology, Stephanie N. Nelms, Kai Herring, Luke Hanke, William Foley

ATU Scholars Symposium

The physicochemical properties of silicon are closely related to carbon. Certain species of plants accumulate high amount of silicon, however, their physiological role and molecular mechanism of sequestration and distribution in plant tissues are poorly understood. The bonding potential of silicon is analogous to carbon and silicon is a key element propelling nanotechnology and digital revolution. Recent discoveries of silicon in Mars and the Moon along with metabolic engineering of enzymes that can incorporate and cleave silicon from organic compounds have consolidated the idea of silicon-based synthetic cellular lifeforms. Bibliometric analysis was used to evaluate the trend of research in …

Della Protein And Cbl-Cipk Signaling Pathway As Candidates For Genetic Engineering, Nathan F. Surles

ATU Scholars Symposium

No abstract provided.

Below-Ground Carbon Gradients Surrounding Saskatchewan's Native Agricultural Copses, Andrea V. Cline, Colin P. Laroque

Aspen Bibliography

As carbon markets develop, understanding the carbon storage capabilities of agricultural land is imperative to maximizing carbon storage. Ecosystems store two-thirds of their carbon below ground. Shrubland and shelterbelt carbon storage have been well documented in agricultural settings, yet little is known about the carbon stored under the native woody vegetation scattered across the Prairies. This study aims to be the first to quantify the below-ground carbon under and around these native trembling aspen (Populus tremuloides) copses in the Canadian Prairies. For this study, the leaf, fibric, humic layer (LFH) and soil samples up to 60cm were collected …

Effects Of Gibberellin On Mutant Dwarf Setaria Viridis Height, Myles Petty, Breslin Clark, Caden Post, Shai Steineger, Hailey Moore, Andrew Thompson, Callie Demarest, Peyton Willeford

2025 Student Academic Showcase

Over the course of 16 weeks, three genotypes of Setaria viridis, two of which display dwarfism and one wildtype, were subjected to 100 micromole solution of gibberellic acid. This was done in order to identify how the height of dwarf mutant millets would change in reaction to gibberellic acid. A total of 216 plants were looked at. 72 of each genotype were used and split between two different treatments, one with gibberellic acid and one without.

The Application Of Gibberellin On Dwarf Mutant Millet Plant (Setaria Viridis), Catherine Philipps, Desirae Snyder, Elizabeth Dill, Joselyn Wood, Kaneez Moughal, Katherine Kellner, Rachel Wilson

2025 Student Academic Showcase

Gibberellin is a hormone found in many plants whose purpose is to promote the growth of stems and leaves. The application of gibberellin in differing concentrations was applied to different strains of dwarf mutant millet plants and was compared to a control of nonmutant wild-type millet plants. After the initial sprouting of each seed, 4 different concentrations of gibberellin: 0g gibberellin/1L water, 0.02g/L, 0.05g/L, and 0.15g/L, were applied to the stem of each plant. A regression analysis was performed on the heights of each plant to determine the effectiveness of the varying gibberellin concentrations on the growth of millet plants. …

Gibberlin In Millet Physiology, Torrie Ens, Bella Reaka, Claire Albrecht, Hannah Smallwood, Will Graham, Adam Staley, Garrett Steger, Erin Strong

2025 Student Academic Showcase

Gibberellin is a hormone in plants that affects growth. Gibberellin works to begin germination in grass seeds by stimulating amylase production. It may be possible to use gibberellin to understand why different millet variants exhibit dwarf growth. We grew and treated 4 different dwarf variants with a gibberellic acid solution to identify the ability of each plant to utilize gibberellin. We compared the growth in millet grown both with and without the solution to see the effects of gibberellin on each variant. Dwarf millets may not produce their own gibberellin, or they may lack the receptors to utilize gibberellin. Our …

Functional And Comparative Genomics Of The C.Sojina- Soybean Interaction, Alejandra Maria Vargas Oyuela

LSU Master's Theses

Frogeye leaf spot (FLS), caused by Cercospora sojina, is a significant foliar disease of soybean (Glycine max) and is responsible for substantial yield losses worldwide. While management strategies rely on host resistance and fungicide applications, the emergence of new virulent races and fungicide-resistant isolates necessitates a deeper understanding of C. sojina host interactions and genomic variability. Here, we employed comparative and functional genomic approaches to decipher the molecular mechanisms underlying the C. sojina-soybean interaction. A dual RNA sequencing approach was used to identify transcriptomic changes in G. max cultivars Blackhawk (susceptible) and Davis (resistant) across multiple …

Trenching And Compost Sustain Grain Yield Increases Over Nine Years On Deep Sands But At A Cost, David J.M. Hall, Tom J. Edwards

Grain and Other Field Crops Research Articles

Context. Crops grown on deep sands on the south coast of WA are limited by soil physical and chemical properties including compaction and poor nutrition. Aims. Crops grown on deep sands on the south coast of Western Australia are limited by soil physical and chemical properties including compaction and poor nutrition. Our aim was to determine what effects deep-placed organic amendments have on soil properties and crop production in a deep sand and whether such amendments are profitable. Methods. A long-term field trial was conducted over nine years (2015–2023) to investigate soil amendments including lime (0 and …

Restoring Exotic Cool-Season Grass Dominated Landscapes With Clethodim And Glyphosate, Eleanor J. Muzzy, Joshua D. Wiese, Abraham J. Kanz

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

A major threat to grasslands around the world is the spread of exotic cool-season grasses (ECSG). ECSG dominate vegetative communities and degrade critical habitats. One of the most common methods to treat ECSG is herbicide. To compare how the widely-used, non-specific herbicide glyphosate compared to the grass-specific herbicide clethodim, we conducted a fall spray in November 2023 at two different sites located in the Central Platte River Valley of Nebraska. The following June, we used a modified Daubenmire frame sampling method to gather data on relative cover, species richness, and community composition. After analysis, glyphosate appeared to be more effective …

Field Calibration Of A Time Domain Reflectometry Sensor For Water Content Measurement In Soils With Low Content Of Coarse Fragments, Rehnuma Maisha, Dean Steele, Aaron L. M. Daigh, Derek M. Heeren, Trenton E. Franz

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Comparison of soil water sensors for irrigation scheduling requires an accurate reference measurement. An Acclima TDR-310H soil water content sensor was calibrated and validated for sand, loamy sand, clay loam, sandy clay loam, and sandy loam soils. In 2021, sensor readings and soil samples were collected in the same sensor volume at depths of 15 and 46 cm at three irrigated field sites with five stations each. Gravimetric water content, bulk density, and volumetric water content (θv) were determined in the lab. The root mean square error was 0.032 cm³ cm⁻³, which was within acceptable limits. The …

Life After Death: Investigating The Resistance And Recovery Of Fungal Communities To Foundation Tree Mortality, Jessie F. Marlenee

Biology ETDs

Tree mortality can have cascading effects on the composition and resilience of interacting fungal communities. Yet, little is known about the impact tree mortality, distinct from abiotic drivers (i.e., drought), has on these communities. This dissertation focuses on the resilience of fungal communities to experimental tree mortality in a piñon-juniper woodland. In chapter one, I found that piñon mortality reduced piñon fine root biomass and piñon mycorrhizal fungal diversity, whereas juniper mycorrhizal fungi were unaffected by juniper mortality. In chapter two, I revealed that piñon mortality altered the composition and spatial structure of mycorrhizal and saprotrophic fungi in the soil, …

Effectiveness Of Silvicultural Options In Renewal Of Trembling Aspen–Jack Pine Mixedwood Stands, 21 Years After Treatment, Rongzhou Man

Aspen Bibliography

Regenerating conifers after harvest through planting and postharvest broadcast application of herbicide is effective in ensuring the survival and growth of seedlings, but faces challenges in meeting broad social and ecological objectives of forest management. This study reports the effectiveness of alternative options in regenerating jack pine (Pinus banksiana Lamb.), 21 years after harvest of trembling aspen (Populus tremuloides Michx.)-dominated boreal mixedwood stands. The treatment options included (i) preharvest spray—aerial broadcast spray prior to harvest, (ii) postharvest partial spray—ground herbicide application in strips, (iii) partial harvest in strips, (iv) postharvest aerial broadcast, and (v) uncut reference. Twenty-one years …

The Effect Of Topping And Various Cytokinin-Based Plant Growth Regulators Applications On Immature Liberica Coffee Growth, Yudithia Maxiselly, Joshua Samuel, Cucu Suherman

Jurnal Kultivasi

The growth of Liberica coffee in the 2-year immature plant phase can be improved by applying cytokinin-based plant growth regulators (PGRs) and topping. Toppings applied to plants can inhibit apical dominance, while cytokinin PGRs such as 6-Benzylaminopurine (BAP) and coconut water can stimulate plant shoot growth. This research aims to determine the effect of topping and PGR application on the vegetative growth of Liberica coffee plants. This experiment was carried out at the Ciparanje experimental field, Universitas Padjadjaran, West Java, with an elevation of ± 750 meters above sea level from March to June 2024. The experimental design used a …