Digital Commons Network^™

The Usu Tree Inventory Website: A Case Study Of An Interactive Online Woody Plant Education Resource, Benjamin W. Harris

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

The USU tree inventory website is an interactive, online tree education resource that I developed to allow students and community members to locate, identify and learn about trees on the USU campus. Students in two USU courses that teach woody plant material used the website during one semester and were surveyed about their experience. Less than half of the students accessed the website, but those that did found it useful as a supplement to traditional instruction. Most students were likely to recommend the website to another person and to use the website in the future.

Selecting And Propagating Clones Of Bigtooth Maple (Acer Grandidentatum Nutt.), Melody Reed Richards

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Numerous wild bigtooth maple (Acer grandidentatum Nutt.) specimens in northern Utah have potential for use in landscapes, but improvements in selection and propagation need to be developed before these specimens can be introduced to the green industry. Criteria-based evaluations centered on aesthetics, function, and fall color were performed to objectively select superior bigtooth maple specimens. Out of 56 trees initially selected for red fall color, six were selected for propagation based on all three criteria. Five of the six selected trees yielded viable bud take via chip budding. Optimum time for chip budding propagation was determined by four experiments. …

Enhancing Out-Of-Season Production Of Tomatoes And Lettuce Using High Tunnels, Britney L. Hunter

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The growing season for vegetable crops is limited by freezing temperatures in arid high elevation climates such as northern Utah. Logan, Utah (41.73 N, 111.83 W, 1382 m elevation) has a short, variable growing season with an average frost-free period of 135 days. Extending the growing season provides growers with an opportunity to extend revenue into a normally unproductive period and benefit from out-of-season price premiums. High tunnels have been used to effectively extend the growing season for numerous crops by providing cold temperature protection. However, limited high tunnel research has been performed in arid high elevation regions that experience …

Phenotypic And Genetic Characterization Of Wildland Collections Of Western And Searls Prairie Clovers For Rangeland Revegetation In The Western Usa, Kishor Bhattarai

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Western prairie clover [Dalea ornata (Douglas ex Hook.) Eaton & J. Wright] is a perennial legume that occurs in the northern Great Basin, Snake River Basin, and southern Columbia Plateau, whereas Searls prairie clover [Dalea searlsiae (A. Gray) Barneby], also a perennial legume, occurs in the southern Great Basin and surrounding areas. Understanding the genetic and ecotypic variation of these prairie clovers is a prerequisite for developing populations suitable for rangeland revegetation in the western USA. DNA sequences of internal transcribed spacer (ITS/5.8S) and trnK/matK were used to study the phylogeny of these species. The species were distinguished …

An Investigation Of The Utilization Of Soil Water And Nitrogen Among Diverse Forage Plant Species And Mixtures, Sallee Reynolds

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Species diversity achieved by adding novel functional groups (warm-season grasses and non-leguminous forbs) to pasture land, along with traditional grasses and legumes, could aid in the capture of nutrients and water in pasture systems by offering complementary rooting architecture to aid in water and nitrogen uptake and decrease nitrogen leaching. Because these species may differ from commonly used grasses and legumes in their seasonal pattern of productivity, they could also extend or enhance growing-season productivity. The goal of this project is to better understand the role of plant diversity in 1) nitrogen use and 2) distribution of rooting dynamics and …

Effect Of Mica Content On Surface Infiltration Of Soils In Northwestern Kern County, California, Steven Keyes Stakland

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A soils infiltration rate (IR) is the measured rate that soil is able to absorb water, either from precipitation or irrigation. A low IR can cause damage to crops if the necessary amount of water cannot penetrate to the plant roots in the time needed. The damage can be common in permanent plantings such as almond and pistachio orchards where regular tillage is avoided. This indicates a physical aspect to the problem because tillage increases IR. However, there is also an electrochemical side to infiltration problems because certain calcium surfactant treatments can increase IR. Various other methods have been used …

Interclonal Variation Of Primary And Secondary Chemistry In Western Quaking Aspen And Its Influence On Ungulate Selection, Damon A. Winter

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Quaking aspen (Populus tremuloides) clones within close proximity to one another can exhibit drastically different levels of browsing by ungulates. The objectives of this study were to (1) determine interclonal differences in plant chemistry between adjacent clones exhibiting different degrees of herbivory which may influence the browsing behavior and patterns of ungulates, and (2) determine if correlation exists in the levels of salicortin and tremulacin between current year's suckers and current year's growth on older trees. This second objective was meant to indicate a protocol for land managers for identifying clones meriting increased protection from herbivory after treatment …

Season Extension Of Strawberry And Raspberry Production Using High Tunnels, Daniel R. Rowley

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

High tunnels have been used successfully in many areas of the world to extend the growing season for numerous crops. However, very little research has been conducted to evaluate the season extension benefits offered by high tunnels to small fruit crops in high elevation growing areas such as the Intermountain West region of the United States. The use of high tunnels was investigated in North Logan, Utah (41.766 N latitude, 1405 m elevation, 119 freeze free days) to extend the growing season for both strawberries and raspberries. June-bearing 'Chandler' strawberries in a fall-planted annual hill system were evaluated for early …

Evapotranspiration Of Kentucky Bluegrass, Lynda L. Fenton

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Rapid population growth in arid regions of the western US is placing increased demand on water resources. Variability in precipitation and common occurrence of drought have promoted scrutiny of water use in urban lawns and gardens. However, few reliable measurements of water use of these landscapes exist. Quantifying the amount of water used vs. required by landscapes such as turfgrass would allow significant water conservation. Evapotranspiration (ET) is affected by biophysical factors such as: available energy, turbulent mixing, saturation deficit, soil water, and stomatal conductance. In order to simulate the water use by turfgrass, the relative importance of these processes …

Optimizing The Physical And Nutritional Environment Of Unleached Root-Zones, Curtis B. Adams

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Unleached root-zones represent an environmental ideal by eliminating wasteful leaching of nutrients and water. NASA grows plants in space in unleached root-zones, incorporating polymer-coated fertilizer (PCF) into a ceramic media (Turface or Profile). However, lack of growth productivity in space has led to the need for research to improve the nutritional and physical environment of the root-zone, which is the objective of this research. PCF types are diverse in release characteristics and the effects of temperature and substrate water content have not been well characterized. In spite of widespread use, studies on chemical properties and applied studies to verify soil …

Biological And Mechanical Approaches To Sunscald Management In Bell Pepper Production, Samuel D. Day

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Producing red bell peppers in high temperature and light environments can be challenging because many new semi-indeterminate varieties produce small plant canopies that leave fruit exposed to damage (sunscald) caused by solar radiation. Pepper production in Utah coincides with high air temperatures and solar radiation levels during July, August, and September. Increasing plant canopy size is one way to protect fruit from solar radiation. Low tunnels optimize plant growth by increasing air and soil temperatures. Growing plants under low tunnels early in the season could increase fruit shading later in the season. Another way to protect fruit is by using …

Comparative Performance Of Fluorometry And High Performance Liquid Chromatography In The Detection Of Aflatoxin M1 In Two Commercial Cheeses, Gustavo Peña

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Aflatoxin M1 (AFM₁) is frequently found in milk and dairy products. It is a metabolite formed in cows from aflatoxin B1 (AFB₁), contained in animal feeds. In cheese production AFM₁ distributes between curds and whey. In this study, cows were fed 64 µg/AFB₁/d for the high treatment, and 5 µg/AFB₁/d for the low treatment, to obtain milk contaminated with AFM1 over the 0.5 µg/L and under 0.05 µg/L restrictions, respectively. Cheese was manufactured with milk contaminated with AFM₁ at 0.8 and 0.03 ìg/kg by the higher and lower …

Regulated Deficit Irrigation Of 'Montmorency' Tart Cherry, Kylara A. Papenfuss

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Regulated deficit irrigation (RDI) is the strategy of reducing irrigation rates during a specific period of growth and development, with the objective of conserving water and managing plant growth while maintaining or improving yield and fruit quality. Mature tart cherry (Prunus cerasus L. 'Montmorency') trees in a commercial orchard were subjected to a range of irrigation deficits from pit hardening to harvest during the 2007 and 2008 seasons. Irrigation treatments replaced from 62% to 96% of ETc, during that period. Midday stem water potential measurements were significantly different among treatments before harvest. However, fresh weight yield at harvest did not …

Reproductive Ecology Of Astragalus Filipes, A Great Basin Restoration Legume, Kristal M. Watrous

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Astragalus filipes Torrey ex. A. Gray (Fabaceae) is being studied and propagated for use in rangeland restoration projects throughout the Great Basin. Restoration forbs often require sufficient pollination services for seed production and persistence in restoration sites. Knowledge of a plant's breeding biology is important in providing pollination for maximal seed set.

Reproductive output from four manual pollination treatments (autogamy, geitonogamy, xenogamy, and distant xenogamy) was examined in a common garden. Pod set, seed set, and seed germination were quantified for each of the treatments. Seed set from four wild populations was compared to that of an openly visited common …

Evaluating Native Wheatgrasses For Restoration Of Sagebrush Steppes, Jayanti Ray Mukherjee

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Pseudoroegneria spicata and Elymus wawawaiensis are two native perennial bunchgrasses of North America's Intermountain West. Frequent drought, past overgrazing practices, subsequent weed invasions, and increased wildfire frequency have combined to severely degrade natural landscapes in the region, leading to a decline in the abundance of native vegetation. Being formerly widespread throughout the region, P. spicata is a favorite for restoration purposes in the Intermountain West. Elymus wawawaiensis, which occupies a more restricted distribution in the Intermountain West, is often used as a restoration surrogate for P. spicata. However, since most restoration sites are outside the native range of …

Genomic Perspectives On Evolution In Bracken Fern, Joshua P. Der

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The fern genus Pteridium comprises a number of closely related species distributed throughout the world. Collectively they are called bracken ferns and have historically been treated as a single species, Pteridium aquilinum. Bracken is notorious as a toxic weed that colonizes open fields and poisons livestock. Bracken is also easily cultured and has become one of the most intensively studied ferns. Bracken has been used as a model system for the study of the fern life cycle, fern gametophyte development, the pheromonal mechanism of sex determination, toxicology, invasion ecology, and climate change. This dissertation places bracken within a global …

The Influence Of Collective Action And Policy In The Development Of Local Food Systems, Lori Porreca

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The modern global agrifood system has had significant negative impacts on consumers and producers. This has precipitated the rise of local food systems that are purported to improve the health and livelihoods of consumers and producers. High expectations have led to significant public and private resources dedicated to the development of local food systems. Despite this, there has been little systematic research exploring the social and institutional conditions that facilitate or frustrate local food system development.

Using a comparative case study approach, this study explored the ways local structural conditions, collective action, food system policies, and the political context affect …

Lifespan Of Prokaryote Model Organism Escherichia Coli K-12, Hyrum Gillespie

Undergraduate Honors Capstone Projects

Bacteria are amazingly resilient organisms, in that they have evolved and adapted to the many extreme environments of Earth (from salt, to pH, to temperature extremes etc.). The bacterial lifespan and death rates are as important as its growth rates in these extreme environments. Bacteria would be useful to determine the effects of age on single cells, but because bacteria reproduce asexually by binary cell fission (clonal replication), calculating the lifespan has proven elusive. Without the determination of a lifespan, age studies using bacteria have limited application. Further, it has been proposed that organisms whose somatic cell line is not …