Digital Commons Network^™

Determining The Origin Of An Isolated Great Lakes Plant Species, Agoseris Glauca (Asteraceae), Seth Paul Hiers

Masters Theses

Small, isolated populations often have low genetic diversity and low potential for adaptation in response to environmental changes. Alternatively, isolated communities are often more likely to display local adaptations and over time speciate. The Great Lakes Region is home to over 50 vascular plant species that are disjunct from the species’ core populations. Agoseris glauca (Asteraceae) is a Great Lakes disjunct and Michigan state threatened species geographically isolated from its core range by 900 km. This study uses Genotyping by Sequencing to assess the population genetics of A. glauca for two Michigan disjunct populations and five western populations in the …

Agricultural Biotechnology In The Courts: Judicial Opinions And Commentary, Drew L. Kershen

Faculty Articles

Seven jurisdictions from around the world have issued judicial opinions that address fundamental issues about the governance and regulatory systems of agricultural biotechnology. This article summarizes these legal proceedings and describes their impact upon agricultural biotechnology. The article then provides a commentary and critique of the legal proceedings and resulting judicial opinions.

High Temperature In Potato: Plant Responses And Adaptive Cultivation Strategies To Increase Production, Siska Rahmayani Gultom, Jajang Sauman Hamdani, Kusumiyati

Jurnal Kultivasi

Climate change, with global temperatures rising by 1.09°C from 1850–1900 to 2011–2020, threatens potato production, a critical staple crop, by exceeding the optimal temperature range of 15–20°C. This review synthesizes over 45 peer-reviewed studies published between 2015 and 2025 from Google Scholar and ScienceDirect to evaluate the physiological, morphological, and tuber quality responses of potatoes to high temperatures and to identify adaptive cultivation strategies for sustainable production. High temperatures reduce photosynthetic efficiency through chlorophyll degradation and stomatal closure, increase respiration, and divert photosynthates to vegetative growth, leading to 18–32% yield losses globally by the 2050s. Heat-tolerant varieties, such as Atlantic …

Optimization Of Rabbit Urine Liquid Organic Fertilizer And Reduced Npk Fertilizer Doses For Improving Growth And Physiology Of Shallot (Allium Ascalonicum L.), Etik Wukir Tini, Rifqi Raditya Kurniawan

Jurnal Kultivasi

Rabbit urine liquid organic fertilizer (LOF) can be used as an alternative fertilizer to reduce the use of inorganic fertilizers, especially for shallots, as a national food commodity. This study aims to determine the best concentration of rabbit urine LOF, the best dose of NPK fertilizer dose reduction, and a combination of rabbit urine LOF and NPK fertilizer dose reduction on the physiological characters of shallot plants. The observed variables consisted of net assimilation rate, crop growth rate, stomatal density, stomatal aperture, and chlorophyll content. The experimental results showed that a concentration of 200 mL L-1 of rabbit urine LOF …

The Effect Of Melatonin And 6-Benzylaminopurine Application On The Post-Harvest Quality Of Cut Roses (Rosa X Alba), Azizah Tiara Putri, Syariful Mubarok, Rahmat Budiarto

Jurnal Kultivasi

Roses are known as a high-value commodity frequently used in various important events. However, they are susceptible to postharvest quality deterioration, which can affect their vase life and appearance. In this study, roses with a blooming stage of approximately 25–50% were immersed in melatonin and 6-benzylaminopurine (BAP) solutions at different concentrations. This research aims to analyze the effect of melatonin and BAP application on the freshness of cut roses. The parameters observed included flower vase life, flower wilting angle, increase in flower diameter, fresh weight, solution uptake, and chlorophyll content. The results showed that melatonin and BAP, applied individually or …

Challenges In Modelling The Impact Of Frost And Heat Stress On The Yield Of Cool-Season Annual Grain Crops, Jonathan Richetti, Victor Oscar Sadra, Di He, Brenton Leske, Pengcheng Hu, Yacob Beletse, C. Mariano Cossani, Ha Nguyen, Bangyou Zheng, David Matthews Deery, M. Fernanda Dreccer, Jeremy Whish, Julianne Lilley

Grain and Other Field Crops Research Articles

Frost and heat events at critical growth stages could cause large yield losses. These temperature extremes are increasing in frequency and intensity due to climate change in many parts of the broadacre cropping regions globally, presenting challenges to food production. For cool-season grain-growing regions, where summers are already too hot, heat and frost risks can limit adaptation options. Capturing these stresses in crop models accurately is increasingly important for evaluating the timing, severity, and yield consequences of extreme events. However, most existing process-based models were not designed to simulate short-duration temperature extremes, limiting their ability to assess climate risk and …

Northern Arizona Ecological Conservation: Assessing Quaking Aspen Health In Northern Arizona Using Earth Observations, Ikram Morso, Luke Collins, Margaret Cox, Melissa Schwan

Aspen Bibliography

Quaking aspen (Populus tremuloides) forests in Northern Arizona provide critical habitat for endangered bird species and support regional tourism and recreation. However, aspen populations are declining due to a combination of abiotic and biotic stressors. In response, land managers implemented strategies, such as ungulate exclusion fencing, prescribed burns, and stand thinning, but efforts are constrained by limited data on where and when to intervene. This project worked in collaboration with the U.S. Forest Service, the National Park Service, the Arizona Department of Forestry and Fire Management, and Northern Arizona University School of Forestry. The team utilized Earth observations …

Growth And Yield Of Curly Red Chili (Capsicum Annum L.) In Response To Mulching And Chicken Manure Application In The Erosion-Prone Area Of Loto, Ternate Island, Tri Mulya Hartati, Lily Ishak, Krishna Aji, Chumidach Roini

Jurnal Kultivasi

Information on soil resources in volcanic landscapes presents a high potential for agricultural land development, but its development is always faced with the potential for continuous land degradation. This study aims to reduce the rate of land degradation through the application of vegetative conservation in erosion-prone Loto agrotourism area, Ternate Island. The research location is focused on erosion-prone areas. The research consisted of a soil resource inventory and a vegetative conservation application. The vegetative conservation application method used a Randomized Block Design (RBD) pattern, composed of 2 factors. The first factor is mulching, namely: no mulching (M0) and mulching (M1), …

Effect Of Preharvest Paclobutrazol And Nitrogen Fertilizers On The Sprouting Performance Of ‘Median’ Potato Seed G0 Tuber, Jajang Sauman Hamdani, Rahmat Budiarto, Anne Nuraini, Selika Fitrian Ramadani

Jurnal Kultivasi

Various intensifications of potato cultivation, such as the provision of paclobutrazol and nitrogen (N) fertilizer, are thought to impact the quality of the seeds produced. This study aims to evaluate the effects of different N fertilizer doses and paclobutrazol concentrations applied in the preharvest period on the sprouting performance of G0 potato tuber seeds after storage. Nine treatment combinations, each repeated three times, were tested, using 50%, 100%, and 150% of the recommended N dose and paclobutrazol concentrations of 50, 100, and 150 part per million (ppm), applied at 30 and 45 days after planting, respectively. The interaction effect between …

Rice (Oryza Sativa L.) Production, Productivity, And Harvested Area In Karawang Regency Under Extreme Weather From 1991-2023, Adine Syabina Buswar, Ruminta, Fiky Yulianto Wicaksono

Jurnal Kultivasi

Climate change occurred in Karawang Regency due to extreme weather events, which are included in the El Nino climate anomaly phenomenon. The existence of extreme weather events in Karawang Regency has decreased rice production, which is a climate-dependent crop. Based on this problem, a study was conducted to analyze the identification of extreme weather changes and correlation analysis of rice crops in Karawang Regency to see the magnitude of extreme weather changes and the influence of extreme weather elements on rice crops. The method used is a quantitative descriptive method by analyzing extreme weather changes, correlation analysis of extreme weather …

Farm Management Practice For The Prevention Of Soil Erosion In The Carnarvon Horticultural Area, Kehinde O. Erinle

Horticulture research reports

The Carnarvon horticultural area has suffered considerable erosion damage following flooding of the Gascoyne River.

The purpose of this report is to describe the factors that contribute to soil erosion in the Carnarvon horticultural area (Section 1), provide guidelines for good soil management (Sections 2) and provide floodway hazard classes and associated soil management recommendations (Section 3).

This report:

• Provides detailed information on soil management for intensive irrigated cropping.
• Details cropping alternatives to better manage the soil erosion risk.
• Identifies appropriate plants for soil stabilisation in a range of situations.
• Promotes the concept of property management plans.
• Takes account of …

Modeling U.S. Corn Production Archetypes In The Agricultural Policy/Environmental Extender Model To Generate Life Cycle Assessment Inventory Data, Brandon Taylor

Graduate Theses and Dissertations

Corn (Zea mays) is an important crop grown across the US for many uses such as grain for animal feed, bio-ethanol production, food products, and industrial products. Corn is produced in almost every state in the US, but most corn production is concentrated in the Corn Belt Region including Iowa, Illinois, Ohio, Indiana, Minnesota, and Nebraska. Although technologies and production practices are improving corn production efficiency primarily through increased yields (improved land use), corn production at this scale greatly impacts the environment through emissions from fertilizer and pesticide runoff and leaching, soil degradation due to improper field practices, as well …

Large Scale Deletion And Rebalancing Within The K1c Kafirin Family In Sorghum, Tyler W. Ferris

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Sorghum bicolor (L.) Monech (sorghum) is cultivated as food for humans and livestock and is valued for its low input requirements. However, sorghum grain protein is deficient in the essential amino acid lysine and has poor protein digestibility because of the abundance of proline-rich kafirins that constitute >70% of proteins that form low-digestibility protein bodies. To reduce kafirin expression in the endosperm, and elicit wholesale proteome rebalancing to increase non-kafirin proteins, a single-guide RNA (sgRNA) Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR/Cas9) construct was previously used to target members of the highly-repetitive alpha-kafirin family, k1C in RTx430 sorghum. The …

Plant Nutrient Interactions In High-Yielding Soybean Environments, Victoria Inklman

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Plant nutrient demands and limitations are usually studied individually by nutrient. Here, we investigated how nitrogen (N) limitation in high-yielding soybean environments affects the uptake, removal, and residual of other plant macro- and micronutrients. The objective of this study was to quantify the uptake, removal, and residual levels of soybean macro- and micronutrients under N-limited conditions and to identify nutrient priorities for high-yielding soybean systems. Aboveground plant samples at physiological maturity were collected in 19 high-yielding soybean fields with N limitation across the state of Nebraska. Reference plots with ample N supply were included within each field to compare macro- …

Crop, Soil Nutrient, And Soil Health Responses Within Integrated Crop And Livestock Systems, Alyssa K. Hall

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

We evaluated the influences of grazing livestock on crop production, soil nutrients, and soil health indicators of integrated crop livestock systems using three experiments during a seven-yr. period. Objectives were to (1) determine livestock grazing and cropping system effects on crop yield and soil properties across six yr. in corn-soybean (C-S) and wheat-corn-soybean (W-C-S) systems with and without periodic composted manure application, (2) explore seasonal variation in soil nutrient patterns over two yr., and (3) measure residual responses for corn grain yield plus soil health indicators in yr. seven following a six-yr. study. In experiment 1, neither livestock grazing ( …

Assessing Grafted Triploid Watermelon And Yellow Nutsedge Growth In Saline Agroecosystems, Joseph F. Bazzle

All Theses

In an effort to better understand how saltwater intrusion events will impact watermelon growers a field trial was conducted to study how saline irrigation water will impact weed growth and seedless watermelon productivity at a joint Clemson University and USDA ARS facility. Weed management has always been a hurdle in vegetable crop production systems, requiring extensive labor even in a conventional setup. For organic growers, often the only economical approach is a combination of mechanical weed control techniques, including plastic mulches, tarps, and hand weeding. For watermelon growers, plastic mulch remains the most effective form of organic weed control available. …

Elucidating The Mechanisms Underlying A Functional Plant-Arbuscular Mycorrhizal Symbiosis Using Omics Approaches, Jasmine Gill

All Dissertations

Arbuscular mycorrhizal fungi (AMF) are obligate biotrophs forming symbiotic association with plants. The plant-AMF symbiosis has gained much attention due to its ability to improve plant nutrient uptake, especially phosphorus, which is often inadequately available to plants due to its limited mobility and complex formation in many soils. Phosphorus (P) is a crucial nutrient for plants, and most phosphate fertilizers are derived from phosphate rock, a finite natural resource. Thus, optimizing P uptake is vital for sustaining crop yields and addressing the needs of a growing global population. Plant-AMF symbioses are significant in this context, as AMF can acquire P …

Stand Strucuture Of Planted Stands In Storm-Water Retention Basins, Jason Lanza

Electronic Theses and Dissertations

Trees assist in stormwater retention basin functionality as efficient sources of water removal, and determining stand structure and leaf area of forests can be a measure of their effectiveness. The structure of forest stands on these basins managed for runoff mitigation has received little attention. We investigated the structure and species composition/diversity (tree and herbaceous) of planted, managed stands and naturally regenerated stands on stormwater retention basins managed by Harris County Flood Control District in Harris County, Texas. We determined stand structure variables (trees per hectare, basal area per hectare, quadratic mean diameter, relative density, average tree height, and percent …

Assessment Of Floral Resources From Three Tamaulipan Thornscrub Communities Of The Lower Rio Grande Valley, Gracie Makenna Granados

Theses and Dissertations

The Tamaulipan thornscrub is a transition zone between the neotropics and the temperate regions, harboring high biodiversity. This habitat supports a diverse insect community, including many pollinators of native and cultivated plants in Texas and northeastern Mexico. This ecosystem has been extensively degraded and lost; only 5% of its original cover remains north of the Rio Grande. Restoration of the Tamaulipan thornscrub has been ongoing for over three decades, but the important roles of pollinators in the success of such efforts and the functioning of the restored ecosystem have rarely been considered in restoration efforts. The purpose of this study …

Exploring Transcriptional Stress Responses In Sorghum And Evolutionary Insights Into Yth Domain Proteins Across Plants, Shikha Bharti

Theses and Dissertations

Understanding how plants respond to abiotic stress is crucial for enhancing crop resilience in the face of climate change. This thesis explores plant stress adaptation mechanisms through two interlinked studies that address different aspects of gene regulation. The first study investigates the transcriptional dynamics of Sorghum bicolor under drought and heat stress at 1-hour and 6-hour time points. By employing 3'-end RNA sequencing, this study provides a comprehensive temporal view of gene expression changes, revealing stress-responsive transcription factors, hormone-associated pathways, and chromatin regulators. The comparative analysis highlights both common and distinct molecular responses between drought and heat stress, providing insights …

Factors Underlying A Latitudinal Gradient In The S/G Lignin Monomer Ratio In Natural Poplar Variants, Jin Zhang, Pradeep Kumar Prabhakar, Yen On Chan, Rachel A. Weber, Mengjun Shu, Ganesh Panzade, Connor J. Cooper, Russell B. Davidson, Jin-Gui Chen, Sara S. Jawdy, Jerry M. Parks, Breeanna R. Urbanowicz, Gerald A. Tuskan, Trupti Joshi, Richard A. Dixon, Wellington Muchero, Jaime Barros

Biomedical Sciences

The chemical composition of wood plays a pivotal role in the adaptability and structural integrity of trees. However, few studies have investigated the environmental factors that determine lignin composition and its biological significance in plants. Here, we examined the lignin syringyl-to-guaiacyl (S/G) ratio in members of a Populus trichocarpa population sourced from their native habitat and conducted a genome wide association study to identify genes linked to lignin formation. Our results revealed many significant associations, suggesting that lignin biosynthesis is a complex polygenic trait. Additionally, we found an increase in the S/G ratio from northern to southern geographic origin of …

Assessment Of A Muscadine Grape (Vitis Rotundifolia) Mapping Population For Tolerance To Pierce’S Disease Pathogen Xylella Fastidiosa And Resistance To Black Rot Disease Pathogen Guignardia Bidwellii, Anushka Tennakoon

Master's Theses

Pierce’s disease (PD) and black rot disease cause severe economic losses for grape production under humid and warm conditions. Identifying resistance genes is crucial for controlling these disease by developing resistant cultivars. Muscadine grape (Vitis rotundifolia) cultivar ‘Pam’ has been identified to possess a high level of resistance to diseases. To elucidate the genetic basis of the resistance to the causal pathogens Xylella fastidiosa and Guignardia bidwellii in this cultivar, parents and 141 F1 individuals developed from open pollinated ‘Pam’ were evaluated for two seasons under natural disease pressure. The mapping population was genotyped using genotyping-by-sequencing (GBS) and …

Temperature Effects On Fruit Doubling And Bloom Prediction In Tart Cherry, Josette M. Moon

All Graduate Theses and Dissertations, Fall 2023 to Present

Tart cherry (Prunus cerasus) is a key horticultural crop in Utah. Extreme summer heat and cold weather in late spring are challenges to tart cherry production causing economic losses. These problematic weather conditions are influenced by the local landscape and are exacerbated by changing climate. This research explores (1) the impact of summer heat stress on fruit deformities, and (2) the accuracy of temperature-based predictions of spring bud development. High temperatures and water stress after harvest are known to cause a deformity known as twin or double fruits, resulting in unmarketable fruit. This disorder has been studied in …

Investigating The Impact Of Psychoactive Plant Alkaloids On Bumblebee Behavior, Skylar Mathieson

Electronic Theses and Dissertations

The relationship between plants and their pollinators is often framed as a food-for-service exchange in which plants provide pollinators with nutrients in exchange for transport of their gametes. However, in addition to essential nutrients, many floral rewards (nectar, pollen) also contain defensive toxins such as alkaloids, with largely unexplored consequences for plant-pollinator interactions. I investigated how three psychoactive and addictive plant alkaloids — caffeine, nicotine, and morphine — affect foraging behavior in generalist bumblebees (Bombus impatiens) using robotic flowers. Each of these chemicals affected pollinator foraging behavior, influencing the number and duration of their visits to flowers in …

Development Of A Machine Learning Framework For An Irrigation Decision Support System, Eric Wilkening, Derek M. Heeren, Yeyin Shi, Laila A. Puntel, Guillermo R. Balboa, Abia Katimbo, Kuan Zhang, Precious Nneka Amori, Bruno Lena

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Currently used irrigation scheduling techniques often require significant human intervention and are time consuming, particularly for variable rate irrigation. This research aimed to develop a conceptual framework that incorporates disparate data sources leveraging both mechanistic and machine learning (ML) approaches. The overarching objective is to utilize the growing availability of data and technology to manage irrigation more precisely, which will minimize negative impacts of irrigation on our water resources. An initial irrigation machine learning model was proposed and tested in this study as a key component of an edge-cloud computing and federated learning decision-making framework. The specific objectives were (1) …

Interactions Of Biorational And Synthetic Dmi Fungicides For Control Of Fruit Diseases, Johanna Wesche

All Dissertations

Biological fungicides are increasingly investigated as sustainable alternatives to synthetic fungicides in fruit crop protection. This dissertation examines the interactions between two commercial biological fungicides, Bacillus subtilis AFS032321 (Theia) and metabolites of Pseudomonas chlororaphis AFS009 (Howler EVO); and demethylation inhibitor (DMI) fungicides, with a focus on compatibility, synergistic potential, and resistance implications. In vitro assays revealed that commonly used DMI fungicides difenoconazole, metconazole, tebuconazole, and propiconazole inhibited vegetative growth of B. subtilis at concentrations above 50 µg/ml, whereas mefentrifluconazole promoted colony expansion. Under controlled conditions, lesion development on detached fruit was inhibited synergistically when Theia was combined with the growth-promoting …

Authentication And Message Integrity Verification For Emerging Wireless Networks, Ebuka Philip Oguchi

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

This dissertation presents a comprehensive body of research on authentication and message integrity verification for emerging wireless networks, focusing on secret-free and physical layer security techniques across diverse, challenging, and unconventional environments.

It comprises four first-author contributions that span underground wireless systems, over-the-air (OTA) channels, vehicular communications, and nanoscale molecular networks.

The first contribution, Soil-Assisted Trust Establishment for Underground Wireless Networks (STUN), introduces a physical-layer trust bootstrapping protocol that achieves authentication and message integrity without pre-shared secrets. Leveraging underground-to-air propagation laws and trusted relay nodes, STUN resists active signal injection attacks and demonstrates security comparable to the unbalanced oil and …

Impacts Of 4r Nitrogen Management And Water Optimization On Soil Health, Kamaldeep Kamaldeep

All Graduate Theses and Dissertations, Fall 2023 to Present

Farmers in Utah and Idaho are facing growing challenges due to high fertilizer costs, limited irrigation water, and pressure to improve long-term soil health. To better understand current practices and grower attitudes, a survey was conducted in 2020 targeting 5,000 producers of small grains, corn, and potatoes. Although the response rate was low, 146 growers representing over 25,000 hectares of cropland participated. Survey results showed that most growers are open to improving nitrogen and irrigation practices and care about their soil health, even if not all are fully using 4R or precision agriculture methods.

This thesis includes two field studies …

Soil Health On Utah's Farms And Ranches, Jenae Dean

All Graduate Theses and Dissertations, Fall 2023 to Present

The term soil health has gained popularity in agriculture due to prolonged droughts, rising food costs, and the growing public concern for sustainable and organic practices. Soil health practices can offer solutions to all of these pressures. This thesis provides Utah's farmers and ranchers with quantifiable data on implementing soil health practices in Utah's unique climate. It presents the first two years of on-farm trial results on yield and quality after implementing various soil health practices on five categories of crops: corn, mixed hay, alfalfa, produce, and dryland grain. Over a two-year period, none of the soil health practices resulted …

Water Conservation Strategies For Growing Ornamental Plants In Utah Landscapes, Jenny L. Koller

All Graduate Theses and Dissertations, Fall 2023 to Present

When early pioneers settled in Utah, they faced challenges living in a dry region with limited water. They built dams, canals, and irrigation systems by working together as a community to manage their water needs. However, adoption of European landscaping methods, farming and rapidly growing population increased water need while climate change and frequent drought reduced water supply.

Today, Utah is one of the driest states and uses more water per person than most other states in the nation. If things don't change, the state could run out of water by 2060. To address Utah's growing water challenges, this research …