Life Sciences Commons^™

Soil Health Monitoring And Management In Corn And Soybean Agroecosystems Of The Midwestern U.S., Bradley S. Crookston

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Soil health is a concept and condition of the soil where measurable soil properties represent the capacity of a soil fulfilling its intended use, such as producing crops, without constraint to its agro-ecological quality. Soil health assessments are used to estimate the health of a soil by assessing soil biological, chemical, and physical attributes, called soil health indicators, and scoring them on a scale, usually 0 to 100, to guide soil and crop management. However, there are few large-scale analyses of soil health assessment scores and their relationships with crop yield. Understanding how soil health assessments relate to crop yield …

Season Advancement Of Cool Season Cut Flower Crops Snapdragon And Peony, Maegen A. Lewis

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Demand and production of specialty cut flowers is growing across the U.S., but research is lacking in the U.S. Intermountain West, where the semi-arid and high elevation climate offers unique challenges for growers. The goal of this study was to evaluate the stem quality, harvest timing, and yield of snapdragon (Antirrhinum majus) ‘Chantilly’, ‘Potomac’, and ‘Rocket’ and peony (Paeonia lactiflora) ‘Coral Charm’ as cool-season cut flower crops under high tunnel and field production in North Logan, Utah. Snapdragons were transplanted at three-week intervals beginning in early-February in high tunnels and ending in late-May in the field. …

Seeding Rate, Herbicide, And Irrigation Effects On Spring-Seeded Oat-Alfalfa Companion Crops, Carson D. Roberts

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Small grain companion crop seeding rate recommendations for alfalfa (Medicago sativa L.) establishment are dated and inconsistent, and how a small grain companion crop seeding rates should be adjusted at different moisture levels is unknown. A study was conducted to provide clarity about oat (Avena sativa L.) companion crop seeding rates that maximize weed suppression and forage yield and minimize the effect on alfalfa stand establishment. This experiment considered oat companion crop seeding rates at various irrigation levels. Companion crop treatments consisted of oats sown at 89, 45, 22, 10, and 0 (with and without herbicide) kg ha …

Mechanisms Of Overyielding And Coexistence In Diverse Tallgrass Prairie Communities, Leslie E. Forero

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Plants compete for the same basic nutrient and water resources. According to the competitive exclusion principle, when a substantial overlap in resource pools exists, the best competitor for resources should drive all other species to extinction. The ability for plants to coexist in violation of the competitive exclusion principle is the “biodiversity paradox”. Coexistence is actually beneficial for plants: as species diversity increases, you typically see increases in plant biomass production (known as the biodiversity-productivity relationship). The mechanisms behind coexistence and the biodiversity-productivity relationship remain an ecological mystery. One hypothesis is that plants obtain water and nutrients from different places …

Soil Health, Phosphorus And Carbon Dynamics In Response To A One-Time Compost Application And Cover Crops In Organic Dryland Winter Wheat, Idowu Ademola Atoloye

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Organic dryland winter wheat (Triticum aestivum) growers in the U.S. are faced with high interannual variability in yields. This is related to the low annual precipitation and low soil fertility on the cultivated soils. Improving soil health is the key to increasing and maintaining crop yields. In this study, we compared the effects of different rates (0, 12.5, 25 and 50 Mg DW ha^-1 compost and 2 Mg ha manure^-1) of large quantities of steer manure compost and the inclusion of cover crops versus fallow on soil health and on carbon and phosphorus dynamics in …

Untangling The Economic And Social Impediments To Producer Adoption Of Organic Wheat, Donya L. Ralph-Quarnstrom

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Consumer demand for organic products has shown double-digit growth in recent years encouraging the development of a wider range of goods (Greene, 2017). Americans with an annual household income under $30,000 actively purchase organic foods at nearly the same rate as households with over $75,000 in annual incomes, 42% versus 49% (Greene et al., 2017). Previous research observed the adoption of organic farming practices on a combination of different grains, fruits and vegetables, meat, and dairy products from across the globe. However, this is the first study to examine the adoption of organic wheat in the Western U.S. By addressing …

A Simple Metabolic Switch May Activate Apomixis In Arabidopsis Thaliana, David Alan Sherwood

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Apomixis, asexual or clonal seed production in plants, can decrease the cost of producing hybrid seed and enable currently open pollinated crops to be converted to more vigorous and higher yielding hybrids that can reproduce themselves through their own seed. Sexual reproduction may be triggered by a programmed stress signaling event that occurs in both the meiocyte, just prior to meiosis, and later in the egg just prior to embryo sac maturation. The prevention of stress signaling and the activation of a pro-growth signal prior to meiosis triggered apomeiosis, the first half of apomixis. The same approach was used prior …

Precision Drought Stress In Orchards: Rootstock Evaluation, Trunk Hydration And Canopy Temperature, Lance V. Stott

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Tree fruit crops are of high value, but use a lot of water. Precision irrigation has the potential to save water while simultaneously improving crop quality. The timing and method of precision water stress in various tree fruit crops has been widely studied. However, in order to successfully employ precision irrigation methods in orchards, an accurate measurement of tree water status is required. Currently, stem water potential is the preferred indicator. However, this measurement is tedious and cannot be automated. Because measurements must be taken near solar noon (approximately 1:30 PM MDT in the summer in northern Utah), the number …

Postharvest Degradation Of Microalgae: Effect Of Temperature And Water Activity, Jacob A. Nelson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Though usually a nuisance in swimming pools and ponds, algae has the potential to be a valuable commodity for use as food and fuel. But before algae butter and biofuel become commonplace, issues with harvesting and storing this new crop need to be overcome. Though there has been ample research into how to grow and use algae, scientists have spent little time figuring out what to do after you pull it out of the water and before you eat it (or turn it into biodiesel). Algae, like all food products, starts to spoil as soon as it is harvested.

This …

Determining Compost Carryover For Optimal Use In An Organic Corn Squash Rotation, Davey J.R. Olsen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In 2008–2011 a graduate project was undertaken by Davey Olsen under the supervision of Utah State University (USU) Plant, Soils and Climate professors, Drs. Jennifer Reeve, Dan Drost, and Astrid Jacobson. The project investigated a new way of measuring the benefits of applying compost to organically certified horticultural crops. In particular, the carryover of these benefits in the three years following a one-time application was studied. A field trial at the USU Organic Farm modeled the carryover of nitrogen and phosphorus in a corn and squash rotation, while laboratory analysis investigated aspects of nitrogen availability and compost decomposition over time. …

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 …

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 …

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 …

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 …

Herbicide, Salinity, And Flooding Tolerance Of Foxtail Barley (Hordeum Jubatum L.) And Desirable Pasture Grasses, Karl R. Israelsen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Research trials performed in the greenhouse compared the tolerance and response of Hordeum jubatum and desirable pasture grass species to herbicides, salinity, and flooding. Desirable grass species used in this study included: 'Fawn' tall fescue (Festuca arundinaceae), 'Garrison' creeping foxtail (Alopecurus arundinaceus), 'Palaton' reed canarygrass (Phalaris arundinacea), 'Climax' timothy (Phleum pratense), 'Alkar' tall wheatgrass (Thinopyrum ponticum), 'Potomac' orchardgrass (Dactylis glomerata), and 'Mustang' altai wildrye (Leymus angustus). Tolerance to herbicides, salinity, and flooding varied significantly among grass species. Herbicide tolerance was tested using four herbicides at five …

Growing Wild: Crested Wheatgrass And The Landscape Of Belonging, Lafe Gerald Conner

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Crested wheatgrass arrived in North America at the turn of the twentieth century through the foreign plant exploration missions sponsored by the United States Department of Agriculture. During the first two decades of the new century, scientists tested the grass at agricultural experiment stations. They determined it was useful for grazing and particularly valuable because it could grow in drought conditions with little or no care and would continue to produce high quality feed even after several years of heavy use. Beginning in the 1930s federally sponsored land utilization and agricultural adjustment programs sponsored the use of crested wheatgrass for …

Ethylene Synthesis And Sensitivity In Crop Plants, Joseph F. Romagnano

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The gaseous plant hormone ethylene is a small molecule that regulates developmental change. Research was conducted in three areas: sensitivity, synthesis, and alterations to synthesis. Vegetative pea plants were more sensitive than radish plants to atmospheric ethylene. Light intensity did not affect ethylene sensitivity. Ethylene synthesis rates were measured for unstressed cotton, corn, soybean, and tomato plants. The per-plant ethylene synthesis rate ranged from 0.1-80 pmol plant^-1 s^-1. However, when normalized to net photosynthetic rate, this range was 1-4 µmol of ethylene synthesis per mol of CO₂ uptake. Diurnal cycles in ethylene synthesis were present in …

Origins Of The Y Genome In Elymus, Pungu Okito

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Triticeae tribe DUMORTER in the grass family (Poaceae) includes the most important cereal crops such as wheat, barley, and rye. They are also economically important forage grasses. Elymus is the largest and most complex genus with approximately 150 species occurring worldwide. Asia is an important centre for the origin and diversity of perennial species in the Triticeae tribe, and more than half of the Elymus are known to occur in the Asia. Cytologically, Elymus species have a genomic formula of StH, StP, StY, StStY, StHY, StPY, and StWY. About 40% of Elymus …

Cattle As Grazing Management And Seed Dispersal Tools For Increasing Native Species Diversity On Great Basin Rangelands, Marina K. Whitacre

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A series of experiments evaluated: 1) the influence of seed intake and gut retention time on seed passage, recovery, and germinability; 2) fecal seeding and broadcast /trampling as techniques to incorporate seeds into a well-established Agropyron desertorum (Fisch.) Schult. stand in Skull Valley , Utah; 3) intensive grazing as a means to reduce Agropyron biomass and increase establishment and survival of seeded species; and 4) the recovery and germinability of seed extracted from dung collected from the field. Two shrubs (Artemisia tridentata Nutt. ssp. wyomingensis Beetle & Young and Atriplex confertifolia Torr. & Frem.), a grass (Elymus elymoides (Raf.) …

Evapotranspiration Using A Satellite-Based Surface Energy Balance With Standardized Ground Control, Ricardo Trezza

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study evaluated the potential of using the Surface Energy Balance Algorithm for Land (SEBAL) as a means for estimating evapotranspiration (ET) for local and regional scales in Southern Idaho. The original SEBAL model was refined during this study to provide better estimation of ET in agricultural areas and to make more reliable estimates of ET from other surfaces as well, including mountainous terrain. The modified version of SEBAL used in this study, termed as SEBAL_ID (lD stands for Idaho) includes standardization of the two SEBAL "anchor" pixels, the use of a water balance …

Uptake And Transformation Of Trichloroethylene By Hybrid Poplar: Laboratory Studies, Julie K. Chard

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Trichloroethylene (TCE) was widely used as an industrial solvent and degreasing agent for most of the twentieth century. It is now a widespread groundwater contaminant. Phytoremediation may be a cost-effective cleanup method for TCE-contaminated soils and groundwater. Studies of environmental TCE fate are complicated by its volatility. The literature reports both significant and insignificant plant uptake of TCE. Conflicting findings may be due to differences in exposure level, conditions, and duration of the studies, or to experimental artifacts from laboratory systems.

This research quantified plant uptake and volatilization of TCE using a unique laboratory system. Hybrid poplar trees were exposed …

Effects Of Phosphorus On No-Till, Minimum-Till, And Conventional Till Irrigated Field Corn, John A. Mckay

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This investigation involved three tillage treatments, fall plowed (conventional) (moldboard IS-centimeter depth), fall chiseled (ripped) (25-centimeter depth), and no-tillage (zero tillage) replicated four times on an established alfalfa field. Rye was planted in the fall and harvested prior to planting the corn. Soil samples contained an average of 5.9 ppm phosphorus in the 0-30 centimeter soil layer, indicating the need for additional phosphorus. Within each tillage treatment, six rows received 11 kilograms/hectare phosphorus with the seed and 34 kilograms/hectare phosphorus side-dressed. Six rows received 45 kilograms/hectare phosphorus side-dressed, and four rows received 0 phosphorus. All 16 rows received 64 kilograms/hectare …

Seedling Rust Of Safflower -- Its Influence On The Performance Of Selected Varieties And Partial Hybrids, Jon James Jensen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Rust-infested and uninfested seedlots of 14 safflower (Carthamus tinctorius) entries (4 resistant lines, 4 moderately or fully susceptible lines, and six F₁ hybrids from crosses between rust-susceptible females and rust-resistant males), were planted in replicated field trials. The four infested entries resistant to seedling rust incited by Puccinia carthami Cda. exhibited average stand losses of 2.4, 8.4, 18.4, and 27.7%. Stand reduction in the resistant entries was not greater than the inherent compensating ability of the surviving plants; consequently, the yield of these entries was not significantly reduced. Plots from the rusted seedlots of the moderately and …

Formation And Control Of Chlorophyll, Solanine Alkaloids, And Sprouts Of Potato (Solanum Tuberosum L.) Tubers And Carbonyl Compound Of Tomato (Lycopersicon Esculentum Mill.) Fruits, S. J. Jadhav

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Part I. Formation and control of chlorophyll, solanine alkaloids, and sprouts of potato (Solanum tuberosum L.) tubers

Incorporation of radioactive carbon from acetic acid-2-¹⁴C (sodium salt), β-hydroxy-β-methylglutaric acid (HMG)-3-¹⁴C, L-leucine-U-¹⁴C, L-alanine-U-¹⁴C, and D-glucose-U-¹⁴C into the predominant glycosidic steroidal alkaloids, ⍺-solanine and ⍺-chaconine of potato sprouts was 4.88, 9.0, 15, 24, and 20 times less than that of mevalonic acid (MVA)=2-¹⁴C (DBED salt), respectively. The efficiency ratio revealed that β-hydroxy-β-methylglutaric acid (HMG)-3-¹⁴C was incorporated via acetate or acetoacetate. The distribution of radioactivity originated from D-glucose-U-^{14 …}

Effects Of Soil Fumigations With Telone And Nemagon On Physio-Chemical And Ultrastructural Changes In Carrot Roots And Sweet Corn Seeds, Maureen Mei-Chu Chen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Carrots (Daucus carota L. cv. Royal Chantenay) and sweet corn (Zea mays L. cv. Iochief) were grown on the Utah State University's Greenville farm in 1969 and 1970. The soil was fumigated with Telone (a mixture of 1, 3-dichloropropene and other chlorinated hydrocarbons) at the rates of 10, 20, and 30 gal/acre and Nemagon (1, 2-dibromo-3-chloropropane) at the rates of 1, 2, and 3 gal/acre one week before planting. Samples of uniformly mature carrot roots were taken for the studies of total carotenes, β-carotene, total and reducing sugars, respiration, and ultrastructural changes; and those of sweet corn seeds for the …

Effects Of Controlled Atmosphere Storage On Quality And Certain Physiological Characteristics Of Lettuce (Lactuca Sativa L., Cultivar "Great Lakes"), Christopher Chi-Chuen Yang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Lettuce heads (Cultivar "Great Lakes") were stored in different concentrations of O₂ and CO₂, including 1 percent O₂ and 1 percent CO₂, 2.5 percent O₂ and 2.5 percent CO₂, 5 percent O₂ and 0 percent CO₂, and 5 percent O₂ and 5 percent CO₂; temperatures of 35 and 70 F; and with or without microbe- and senescence-inhibiting chemicals and packaging. The samples were taken on the twentieth and fortieth days in the first series of experiments; and in the subsequent experiments, on the fifteenth, thirtieth, …

Effect Of Fluoride On Respiratory Enzymes In Soybean Leaves, Arthur Chiu-Eng Lee

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

There are many reports relating the effects of fluorides on plant respiration. Fluoride has been regarded as an inhibitor of respiration. Warburg et al. (1942) demonstrated that fluoride inhibited enolase activity, therefore, decreased the respiration rate of yeast. Miller (1958), found a similar inhibition of enolase from pea seed. Bonner (1948), Bonner and Wildman (1946), and Laties (1949) reported that the fluoride ion in culture solutions reduced the respiration rate in Avena Coleoptile, spinach leaves and barley roots. Since the inhibition was reversed by the addition of pyruvate, they concluded that the inhibition of respiration was due to the inactivation …

Estimation Of Optimum Plot Size And Shape For Use In Safflower Yield Trials, Alfred Max Wiedemann

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

One of the big problems encountered in experimental yield trials of field crops is the variation that occurs in yield estimates regardless of how the trial is handled with respect to variety or treatment. This so-called "natural" variation is the result of such factors as heredity, human error, and environment.

The Use Of Tetrazolium As A Measure Of The Salt Tolerance Of Alfalfa, Daryl A. Freter

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The task of obtaining and selecting plants which may not only survive under salty conditions, but grow and produce satisfactory yields is varied and complex. It is becoming necessary to select and breed crops for salt tolerance. Plants can be grown in artificially constructed salt basins to test their individual salt tolerance, but this takes time, at least one year. It would be desirable to develop a rapid test to determine the salt tolerance of a given plant. The use of a dye in conjunction with a series of salt solutions has been suggested for determining the salt tolerance of …