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Modifying The Comb, Rethinking The Install: Integrated Approaches To Honey Bee Colony Establishment And Winter Survival, Shelby A. Kittle

Department of Entomology: Dissertations, Theses, and Student Research

The European, or Western honey bee (Apis mellifera L.) plays a vital role in global ecosystems and agriculture, providing essential pollination services and producing valuable hive products. However, honey bee colony losses have escalated worldwide, but particularly across the United States due to various stressors, including biotic and abiotic factors, mismanagement, and environmental challenges. This thesis investigates key challenges in honey bee management and explores solutions aimed at improving colony health and productivity.

Chapter 1 provides an overview of the beekeeping industry, detailing its economic importance, services, and products, as well as the many challenges faced by beekeepers. It …

Leveraging Historical Data For Estimating Genetic Gain And Implementing Genomic Selection In A Student Led Barley Breeding Program, Sydney Graham

Department of Statistics: Dissertations, Theses, and Student Research

In Nebraska, winter feed barley presents an emerging market for producers and an opportunity to diversify cropping systems. The University of Nebraska Barley Breeding Program aims to develop high-yielding, winter-hardy varieties. A unique aspect of this program is that doctoral students serve as barley breeders and are responsible for crossing, data collection, and advancement decisions. While this provides hands-on experience for the students, the impact of student leadership has not been examined.

This study used a historical data set to evaluate the realized genetic gain of the breeding program, and as a training population for genomic selection. The dataset consisted …

Advancing Mitochondrial Dna Visualization And Dynamics In Plants: Application Of The Mt-Hi-Ness Fluorescent Marker, Madeleine H. Faber

Honors Program: Senior Projects (Public)

Mitochondrial DNA (mtDNA) plays a crucial role in cellular energy production and inheritance, yet its dynamics and exchange remain poorly understood in plant systems due to limitations in visualization techniques. Traditional visualization methods such as exogenous DNA stains and fluorescent protein markers present challenges in specificity and live-cell imaging. To address this challenge, we adapted the MT-HI-NESS fluorescent marker, originally developed for mammalian cells, for use in plant mitochondrial studies. Using Arabidopsis thaliana as a model system, we employed mitochondrial targeting sequences (IVD and AOX) to ensure accurate localization and to confirm mtDNA binding specificity. The validation process included fluorescence-based …

Maximizing Crop Production And Profitability Through Double Cropping Corn And Soybean Systems In South Carolina, Bennett Harrelson

All Dissertations

Profitability is critical for farm sustainability, efficiency, and longevity. Over the last decade, corn and soybean commodity prices have fluctuated considerably, and more recently, extreme increases in input prices have narrowed profit margins. Non-traditional cropping systems that can boost profit are becoming of interest to farmers in South Carolina, specifically double cropping soybean behind corn. In this scenario, corn is harvested at high moisture contents and followed by ultra-late planted soybean. However, prior research related to the agronomic production practices of double cropping corn and soybean is minimal. To develop best management practices for growers interested in double cropping corn …

Speed Breeding And Fungal Blight Testing Of The Darling 54 American Chestnut (Castanea Dentata), Virginia G. May

All Theses And Dissertations

The American chestnut (Castanea dentata) was a dominant, foundational forest canopy species in eastern North America until an imported chestnut blight (caused by Cryphonectria parasitica) rendered it functionally extinct across its native range. Biotechnological approaches, like the Darling 54 transgenic line, have potential for future restoration, but need both lab and field evaluations of their breeding and blight tolerance. This thesis adds to the body of knowledge on the Darling 54 American chestnut. This research reports three novel advancements made through indoor breeding and the first systematic field test for blight tolerance of transgenic American chestnuts.

Historically, …

A Case Study On Readiness Of Engineers In Agricultural Technology Start-Ups, Katie Marie Mowat

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

This dissertation explores the perceptions of practicing engineers regarding the skills necessary to be workforce-ready at agricultural technology (ag-tech) start-ups in the Midwestern United States. A qualitative case study methodology is leveraged, combining both interview and job description data. Given their uniqueness, the study divides the ag-tech start-up industry into two subcases: livestock and cropping systems. The Work Readiness Integrated Competence Model (WRICM) is used as the theoretical framework for this study and informs the conceptual framework and analysis processes. The study identified skills that fit into thirteen distinct categories, which are further grouped into four overarching resource groups. Skills …

Gene Editing Approaches To Improving Grain Amino Acid Profiles In Maize And Sorghum, Joseph Preston Hurst

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

Maize grain is deficient in lysine. While the opaque2 mutation increases grain lysine, o2 is a transcription factor that regulates a wide network of genes beyond zeins, which leads to pleiotropic and often negative effects. Additionally, the drastic reduction in 19kDa and 22kDa alpha-zeins causes a floury kernel, unsuitable for agricultural use. Sorghum, closely related to maize, has a similar lack of lysine that can be corrected with prolamin alteration and also subject to the same deleterious kernel texture. CRISPR/cas9 gives researchers the ability to directly target genes of interest. In this research, gene editing was used to specifically target …

Assessing Phenotypic Variation Across Generations Of Iberodes Littoralis Under Climate Change, Mariangel M. Fernandez Silva

Electronic Theses, Projects, and Dissertations

The consequences of climate change and anthropogenic activity have decreased wildlife biodiversity. Plants are particularly vulnerable to climate change due to their large biomass on the planet and sessile nature. A particularly useful method for plants to cope with environmental changes is phenotypic plasticity. Adjusting morphological traits through plasticity can help plants cope with environmental changes. Furthermore, plastic responses can be passed down through methods such as changes in DNA sequence or epigenetic modifications.

Our research project focuses on an herb, Iberodes littoralis, a species of concern native to the Siberian Peninsula with approximately thirteen extant populations. The data that …

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. …

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 …

International Rice Outlook: International Rice Baseline Projections 2024–2034, A. Durand-Morat, W. Mulimbi

AAES Research Reports and Research Bulletins

• Global rice consumption is projected to exceed global rice production for most of the coming decade, with stocks playing a crucial role in balancing the global market over the projected period.

• The projected growth in production is almost exclusively due to productivity gains.

• The projected global rice consumption is growing, driven mainly by population growth. However, the average global per capita rice consumption is estimated to increase slowly in the coming decade due to a regain in per capita consumption in Asia, the largest rice-consuming region worldwide.

• The international prices of long-grain and medium-grain rice are …

High-Throughput Phenotyping Of Early Generation Small Grains Breeding Lines To Indirectly Select For Grain Yield, Dalton Jones

All Graduate Theses and Dissertations, Fall 2023 to Present

In small grains breeding programs, breeders aim to develop better varieties by selecting for important traits like grain yield. However, it takes many years before yield can be measured because several generations of selection are required to fix lines and increase sufficient seed for yield measurements. This process can be slow and expensive

High-throughput phenotyping (HTP) is a modern approach that can increase breeding efficiency by leveraging technology to quickly measure secondary traits which can be used to indirectly select for important traits in crop plants. For example, researchers can use cameras on unmanned aerial vehicles (UAVs, i.e., drones) to …

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 …

Screening Of A Diversity Of Legumes And Non-Legumes Forb Species At Five Strategic Locations Across Utah For The Development Of Smart Foodscapes, Surbhi Verma

All Graduate Theses and Dissertations, Fall 2023 to Present

Grass-dominated rangelands in the Western United States often lack sufficient protein for pregnant cows after grasses mature in mid- summer, leading ranchers to rely on expensive feed supplements such as protein cubes or alfalfa hay. The goal of this study was to screen 27 perennial legume and forb species with the potential to remain green into late summer and provide sufficient protein to supplement cows on grass-dominated rangeland. Three experiments were carried out to understand germination of species, plant establishment and persistence at five Utah locations, and agronomic characteristics. The seed of five hard-to-germinate species were studied for the ability …

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 …

Initial Impacts Of Different Fertilizers On Improved East Texas Equine Pastures, Carolina De Leon, Brian Oswald, Leland Thompson, Candis Scallan

Electronic Theses and Dissertations

ABSTRACT

In Texas, approximately 1.6 million acres support an equine population exceeding 748,000 horses. This study assessed the effects of organic and inorganic fertilizer treatments on improved Bermudagrass (BG) and other vegetation (OTH) in overgrazed equine pastures at the Stephen F. Austin State University Equine Center. Treatments included equine manure (H), broiler poultry litter (P), and a commercial 13-13-13 fertilizer (C), with application rates based on pasture requirements.

Initial vegetation cover was evaluated using the Daubenmire cover class method in September 2024, followed by a 60-day undisturbed growing period. Final biomass (g/2ft² converted to lbs/ac) and percent cover measurements were …

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

ATU Scholars Symposium

No abstract provided.

Floating And Submerged Plants Of Utah: Pocket Field Guide, Kate Sinnott, Karin M. Kettenring

All Current Publications

This is a field guide to identifying floating and submerged plants of Utah. We include a page for each species and also a dichotomous key at the end for the pondweeds. Submerged and floating plant species play critical roles in aquatic ecosystems. They provide habitat to aquatic organisms, improve water clarity by trapping sediment, and absorb excess nutrients from the water column, among other vital services. However, they have been threatened and degraded by pollution, land conversion, and introductions of harmful species. Identifying native and non-native plants is an important component of tackling this degradation and promoting the conservation 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 …

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, …

Grassland For Our World, F Riveros

IGC Proceedings (1977-2023)

The present-day role of grasslands and fodder is reviewed with respect agriculture, animal production and environmental concerns. The world 's grazing lands are a finite resource nnd, overall, are being badly mnnaEed; in most developing countries action is required now, before it is too lnte. They will continue to be a major source of animal feed for the foreseeable future; encroachment from cropping will con

Effect Of Irrigation On Vegetation Succession And Forage Regerneration, Fu Jing-Yan

IGC Proceedings (1977-2023)

No abstract provided.

On The Cultivation And Utilization Of Floret Silvergrass (Miscanthus Floridulus) In The Southern Area Of China, Zhu Bangchang

IGC Proceedings (1977-2023)

The plant genus Miscanthus (silvergrass) includes eight species and one variety in China. In the tropical and subtropi­cal area of south China, the silvergrass distributed widely includes the following seven species : Floret silvergrass ( Miscanthus floridulus), Chinese silvergrass ( M. sinensis), Sugary silvergrass ( M. sacchariflorus), Short-hair silvergrass ( M. brevipilus j, Eulalia silver grass ( M. eulalioides), Szechuan silvcrgrass ( M. szechuanensis), Nepal silvergrass ( M. nepalen�� sis). One of them, Floret silvergrass, is the widest in distri­bution and the highest in economical value, and plays a most important role in …

Herbage Dynamics And Plant-Animal Performance On Altered Northern Great Plains Rangelands, P O. Currie, D C. Adams, J D. Volesky

IGC Proceedings (1977-2023)

Mechanical, chemical, and seeding treatments have been used on rangeland to increase herbage production (Griffith et al., 1985). These treatments are generally applied to rangelands in a low serial stage of succession. Improving these rangelands is of major economic importance to livestock producers attempting lo increase the efficiency of their operations. Our study evaluated 5 range improvement treatments for improving herbage and ani­mal production efficiency

Methodology To Determine Planting Time In King Grass (Pennisetum Sp.) Using Historical Climatic Indices, J R. Ayala, M Sistachs, R S. Herrera

IGC Proceedings (1977-2023)

The determination of planting time by field trials has various disadvantages. These trials should be repeated at least for 3 years comparing different months and the extension of the results is limited. The analysis of the climatic effects would allow a greater generalization with correlations between cli­matic and establishment indices. The season of the year in which the highest number of correlations with monthly histori­cal climatic values are fulfilled is required so as to determine planting time. The objective of the present methodology is to select planting time by using correlations between climatic and establishment indices and the monthly characterization …

Methods For The Establishment Of Leucaena Leucocoephala In Cuba, T E. Ruiz, G Febles, N Sistachs, L E. Diaz, G Bernal, J J. Leon

IGC Proceedings (1977-2023)

Studies in tropical and sub-tropical regions of the world on the factors influencing the establishment and early manage­ment of legume swards as pure cultures have not been carried out integrally. Thus, the objective of the present study was to define the best options of the main components so as to develop a technology for establishing Leucaena leucocephala under our conditions.

Studies On Seed Storage And Sowing Time Of Leucaena Leucocphala In Cuba, T E. Ruiz, G Febles

IGC Proceedings (1977-2023)

Germination of stored seeds and sowing time are essential factors that must be known when a technology for pasture utili­zation is required (Febles and Ruiz, 1986; Ruiz and Febles, 1986). Thus, these experiments were set out to learn the per­formance of the seed quality of Leucaena leucocephala cv Peru stored under different conditions and to determine the influence of the sowing time of this species during the rainy season.

Factors Influencing Pasture Establishment And Persistence In The Mid-Altitude Zone, Yunnan, Southern China, Kui Jia-Xiang, R N. Glencross, Ai Hongxin, Chen Xiong

IGC Proceedings (1977-2023)

The mid-altitude zone in Yunnan Province of SW China ranges from 1500-2500 m in altitude and has a climate inter­grading between sub-tropical and temperate with a mean temp. of 7-10°C in the coldest month and 19-22 °C in the hottest month. The annual rainfall ranges from 800-1200 mm with 80 % falling in the monsoon period, May to September. About 80 % of the total 39.4 m ha of the province is in this very hilly mid-altitude zone. (He et al., 1982) Native grassland vegetation is dominated by Themeda trianda, Arundinella radoli, Imperata cylindrica and some other grasses such as …

Obtention Of King Grass (Pennisetum Purpureum) Clones From Tissue Culture. Selection And Evaluation Of Mutants, R O. Martinez, M Monzote, R S. Herraera, R Cruz, V Torres

IGC Proceedings (1977-2023)

King grass (2n = 28) is widely used in Cuba for forage pro­duction. The increase in the variability of this species is there­fore of special interest in agriculture. Tissue culture as a tech­nique to produce and select somaclones from the king grass donor was used to obtain variability. These were obtained when the apical meristems were cultivated in MS medium with 3 mg/I of 2,4 D to regenerate the plants with different hormonal combinations. Those of 0.1 mg/! of kinetine (Martinez, 1986) were prominent. The variability in the selection and evaluation processes is exposed in this paper.