Plant Sciences Commons^™

Investigating Nectar Rhythms In Squash (Cucurbita Pepo): Effects On Honey Bee (Apis Mellifera) Foraging Behavior., Samuel David Boyd

Electronic Theses and Dissertations

Experiments were performed to investigate the influence of water availability on the diel patterns of nectar secretion (volume, concentration, sugar production) in male squash flowers as well as to discover what physical component of nectar honey bees use to trigger their time-memory. Squash plants were grown in the greenhouse and in the field under both constant and variable watering regimes. Throughout anthesis, nectar volume and sugar concentration were recorded. In the field, the temporal distribution of arrivals to squash was observed with and without blossoms present. In the greenhouse and in the field, squash flowers exhibit a consistent diel pattern …

Morphological And Molecular Systematics Of Psychodidae (Diptera), Gregory Russel Curler

Doctoral Dissertations

A general overview of family Psychodidae is given. Genus Eurygarka Quate is revised to include three species. Genus Gondwanoscurus Jezek is revised to include seven species. The status of genus Stupkaiella Vaillant is revised. Eight new Nearctic species: Eurygarka cyphostylus sp. nov., E. nelderi sp. nov., Stupkaiella lasiostyla sp. nov., S. robinsoni sp. nov., S. capricorna sp. nov., Trichomyia rostrata sp. nov., Australopericoma delta sp. nov., and Threticus thelyceratus sp. nov., and two new Oriental species: Gondwanoscurus cruciferus sp. nov. and G. ornithostylus sp. nov. are described. Two Nearctic species: Eurygarka helicis (Dyar) and Stupkaiella bipunctata (Kincaid), and four Oriental …

Nontarget Host Utilization Of Thistle Species By Introduced Biological Control Agents And Spatial Prediction Of Non-Target Feeding Habitats, Gregory J. Wiggins

Doctoral Dissertations

Rhinocyllus conicus Fröelich and Trichosirocalus horridus (Panzer) were introduced from Europe into North America as biological control agents of the exotic weed species Carduus nutans L. Concern exists over the feeding of these weevils on at least 25 species of native Cirsium thistles. Research was conducted to 1) estimate phenological synchrony of the eight thistle species in Tennessee with R. conicus and T. horridus, 2) investigate naturally-occurring populations of the five native Cirsium thistle species for non-target activity by R. conicus and T. horridus, 3) quantify the impacts to plants of each thistle species to feeding of R. …

The Malawi Project: From Conventional To Holistic Decision Making, Grace Wetmore

Animal Science

How the Cal Poly Malawi Appropriate Technologies Team, and other development groups, can use Holistic Management to aid developing countries in an effort towards a sustainable future.

Impacts Of American Student Teachers On Twelve Community Members In A Rural New South Wales Community Australia: A Qualitative Study, Tera Shenae Bunch

Masters Theses

The purpose of this study was to evaluate the influences of American student teachers on a rural community in New South Wales, Australia. The study analyzed interviews with twelve participants of the American student teacher program in A Rural New South Wales community, Australia. Two researchers worked together to complete this study. Both researchers were student teachers with the New South Wales community for ten weeks and taught Agriculture in one the community‟s two high schools. After allowing one year to pass, researcher one returned to the community to interview twelve individuals involved with the program. The interviewed participants were …

Light-Related Photosynthetic Gene Expression And Enzyme Activity In The Heterokont Alga Vaucheria Litorea And Its Symbiotic Partner The Sacoglossan Mollusc Elysia Chlorotica, Kara M. Soule

Electronic Theses and Dissertations

Photosynthesis is comprised of tightly coupled reactions and therefore requires strict matrices of regulation, particularly involving alterations in gene expression and enzyme activity within the nucleus and plastid. Extensive research has been carried out on these light-regulated mechanisms in plants and green algae, however, much less is known in the red algal lineage, including heterokonts. The goal of this study was to investigate the influence of light on photosynthetic gene expression and select enzyme activity in the heterokont alga Vaucheria litorea and its symbiotic partner Elysia chlorotica, a photosynthetic sacoglossan mollusc (sea slug). Elysia chlorotica harbors V. litorea plastids …

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 …

Discovering Metabolic Networks Of Bovine Fertilization, Erin Lynn Young

Undergraduate Honors Capstone Projects

At the time of fertilization, a dramatic change occurs in the oocyte that transforms this cell from a metaphase arrested state into a metabolically active and dynamic state. The view of the flow of biological processes within organisms has recently shifted from that of a linear path to a more complex network. Biological processes are no longer thought of in the simple terms of DNA to RNA, RNA to proteins, and proteins to final activity. It is now known that many biological processes involve interconnected networks and feedback loops in which DNA, RNA, proteins, and metabolites perform specific roles. We …

A Study Of The Effects Of Applying Flue Gas Desulphurization Gypsum To Various Agronomic Crops, Jordan Ryan Combs

Masters Theses

Flue Gas Desulfurization (FGD) gypsum is a potential soil amendment for agricultural use in the state of Tennessee. FGD gypsum is a potential source of calcium and sulfur that may improve the soil both chemically and physically. FGD gypsum has the potential to raise pH, improve soil structure, increase infiltration rates, ameliorate subsoil acidity and improve crop yields. However, the addition of gypsum can also lower pH in some circumstances and cause magnesium and potassium losses in soil. In this study FGD gypsum was applied at a single rate to fields on thirteen farms located on the northern and southern …

The Effects Of Ultraviolet Radiation On Pigment Production, Growth, And Photochemical Efficiency In Allium Spp, Kristin Renee Abney

Masters Theses

In the 1970s, a push for research on the effects of ultraviolet (UV) radiation on food crops began. Since that time, multiple agricultural and horticultural crops have been studied with results showing that the morphological and physical reactions are species dependent. The purpose of these studies to determine how increasing UV radiation affects Allium fistulosum L. (scallion onions) and Allium tuberosum Rottl. (garlic chives), and how UV radiation affects 16 cultigens of A. fistulosum. The effects of UV radiation were determined by shoot height, fresh weight, carotenoid and chlorophyll pigment concentrations, and photochemical efficiency (F_v/F_m). …

Effect Of Selenium On Glucosinolate And Isothiocyanate Concentrations In Arabidopsis Thaliana And Rapid-Cycling Brassica Oleracea, Thomas Casey Barickman

Masters Theses

Brassica vegetables play a unique nutritional and sensory role in human diets around the world. Their characteristic flavors come from the break down products of glucosinolate (GS) compounds, a large group of nitrogen (N) and sulfur (S) containing glucosides. Glucosinolates are hydrolyzed by myrosinase to isothiocyanates (ITCs) which are biologically active. Mounting evidence of this process is of scientific interest due to the potential for high consumption of Brassica vegetables containing several GSs and their respective hydrolysis products that are associated with cancer chemoprevention. Glucosinolates are sulfur-rich hydrophilic, nonvolatile plant secondary metabolites; and. over the past few decades, their importance …

Remote Sensing Of Harmful Algal Blooms In The Mississippi Sound And Mobile Bay: Modelling And Algorithm Formation, Dan Martin Holiday

Dissertations

The incidence and severity of harmful algal blooms have increased in recent decades, as have the economic effects of their occurrence./The diatom Pseudo-nitzschia spp. caused fisheries closures in Mobile Bay during 2005 due to elevated levels of domoic acid. In the previous 4 years Karenia brevis counts of >5,000 cells L"1 have occurred in Mobile Bay and the Mississippi Sound. Population levels of this magnitude had previously been recorded only in 1996. Increases in human populations, urban sprawl, development of shoreline properties, sewage effluent and resultant changes in NP ratios of discharge waters, and decline in forest and marsh lands, …

Techniques For Triggering Germination Of Adenostoma Fasciculatum In Revegetation Projects At Rocky Canyon Quarry, Stephanie B. Scolari

Master's Theses

Rocky Canyon Quarry is a granite mine located in the Santa Lucia Mountains about 5 miles southeast of the city of Atascadero. The Surface Mining and Reclamation Act (SMARA), which passed in 1975, dictates that California mines must rehabilitate lands disturbed by mining operations. Dr. V. L. Holland and his students in the Biological Sciences Department at California Polytechnic State University, San Luis Obispo (Cal Poly) have been working on restoration and revegetation of the Rocky Canyon Quarry since the early 1990’s.

Adenostoma fasciculatum (chamise) dominates the chaparral communities (chamisal chaparral) found in Rocky Canyon. Chamise is the most common …

Biological Control Of Purple Loosestrife (Lythrum Salicaria): Factors Affecting Galerucella Pusilla And Galerucella Calmariensis Establishment In Tidal Areas, Lynda Kathryn Moore

Dissertations and Theses

Galerucella pusilla and G. calmariensis have provided successful biological control of purple loosestrife (Lythrum salicaria L.) in non-tidal areas but only marginal control in areas of tidal influence. While a previous study identified mechanical scour by tidal waters as the main cause of establishment failure, purple loosestrife stem density explained more than 80% of the variability in presence and absence of Galerucella at my study sites in the Columbia River Estuary. A logistic regression model using purple loosestrife stem density, elevation, and their interaction as predictors accurately predicted 92.5% of Galerucella presence or absence observations of a test data …

No-Till Tomato Production, Bradley L. Booker

Master's Theses

Tillage increases erosion rates and diminishes the quality of soils but has traditionally been a way to manage weeds and prepare a seedbed. No-till vegetable production can ameliorate the ill-effects of tillage in an economically effective way but has not been studied much in California. The objective of this thesis was to determine the viability of no-till vegetable cropping on the Central Coast of California. Tomatoes were grown in no-till and conventionally tilled treatments. Total yield, fruit weight, weed emergence, soil bulk density, soil aggregate stability, and soil organic carbon content were measured and compared. Yields and soil tests in …

Effect Of Water On Micronutrient Content And Yield In Rice (Oryza Sativa L.), Sheila Lorraine Baker

Master's Theses

Rice (Oryza sativa L.) is an important crop in many countries. According to the IRRI, more than 2 billion people globally depend on rice as a staple food (Dawe, et al. 2003). Studies on micronutrient content in rice and the effect of water in availability of the nutrients may aid in decreasing global nutrient deficiencies. Rice is grown under different water regimes such as AWD and intermittent flooding, sprinkler and furrow irrigation. A greenhouse pot experiment of rice utilizing a split plot design under different water regimes was conducted to assess the affect of water on (1) DTPA extractable soil …

Impact Of Weed Management Practices On Grapevine Growth, Yield Components, Plant And Arthropod Abundance, And Carabid Seed Predation In Paso Robles Vineyard, Paolo Sanguankeo

Master's Theses

In the Central Coast of California, USA, wine grape growers are making efforts to identify weed control practices that promote biodiversity in their vineyards while maintaining yields. A field study was conducted in Paso Robles, CA in 2006 and 2007 evaluating the effect on Zinfandel grape-vine growth and production, groundcover plant, and ground dwelling arthropod communities of five weed control practices: 1) flumioxazin, 2) simazine, 3) cultivation, 4) cover crop, and 5) untreated control.

The herbicide treatments had the lowest weed biomass followed by the cultivation, being approximately 10 and 2 times lower than the weed biomass of either the …

Nitrogen And Phosphorus Remediation Of Aquatic Garden Plants In Laboratory-Scale Constructed Wetlands., Robert Polomski

All Dissertations

This research investigated the potential of growing marketable aquatic garden plants that also remediate nursery and greenhouse runoff in a subsurface-flow constructed wetland. The cost of wastewater treatment is offset by the production of revenue-generating horticultural crops. Aquatic garden plants that offer the dual benefits of nutrient remediation and aesthetic value may also be planted in bioretention basins, rain gardens, buffer zones, and filter strips.
Fifteen commercially available aquatic garden plants were grown for 8 weeks in a laboratory scale subsurface wetland in a greenhouse and received nitrogen (N) and phosphorus (P) from Hoagland's nutrient solution every two days for …

Diseases Of Floriculture Crops In South Carolina: Evaluation Of A Pre-Plant Sanitation Treatment And Identification Of Species Of Phytophthora, Ernesto Robayo Camacho

All Theses

This project was composed of two separate studies. In one study, the species of Phytophthora that have been found associated with diseased floriculture crops in South Carolina and four other states were characterized and identified using molecular (RFLP fingerprints and DNA sequences for ITS regions and cox I and II genes), morphological (sporangia, oogonia, antheridia, oospores, and chlamydospores), and physiological (mating behavior and cardinal temperatures) characters. In addition, sensitivity to the fungicide mefenoxam was determined. In all, 87 isolates from 63 host plants that were collected over a 13-year period (1996 through 2008) were examined. Host plants came from 46 …

Influence Of Silvicultural Treatment, Site Characteristics, And Land Use History On Native And Nonnative Forest Understory Plant Composition On The Penobscot Experimental Forest In Maine, Elizabeth Bryce

Electronic Theses and Dissertations

This study investigates forest understory plant diversity and composition in managed and unmanaged stands within the context of a long-term silvicultural experiment in the Acadian Forest of Maine. I examined the effects of silvicultural intensity and past land use on understory plant species diversity and composition. Silvicultural treatments include three variants of the selection system, three variants of the shelterwood system, modified and fixed diameter-limit cutting, and an unregulated harvest. Two types of unmanaged stands were studied: a continuously forested natural area and secondary forest stands on old fields. Chapter 1 presents analysis of understory plant diversity and composition in …

“Growing Up Green: A Study Focusing On Environmental Attitudes, Knowledge And Focusing On Environmental Attitudes, Knowledge And Behaviors Of Elementary Children.”, Sarah Elizabeth Smith

Masters Theses

“Growing Up Green,” is a research based environmental education program that teaches children about recycling, energy conservation, and composting. This program was taught to fourth grade students at H.B. Williams Elementary School, in White House, Tennessee. The children were given a pre-test before the program and a post-test two weeks after the program. The pre and post-test was composed of three parts. The three parts tested their environmental attitudes, knowledge, and behaviors. The study found that most of the children already had positive attitudes toward the environment. While, their attitudes decreased minimally after the program, they still remained very positive. …

Soybean Enhancement For Improved Biodiesel Production, Benjamin David Fallen

Masters Theses

As energy prices continue to rise, concern grows about the economy and about petroleum supplies. On January 1, 2009 The Energy Independence and Security Act of 2009 was enacted. It states that 500 million gallons of biomass-based biodiesel must be produced in 2009 and 1 billion gallons by 2012. In the United States 90 % of the biodiesel is produced from soybean oil, despite its shortcomings. The biggest problem facing the soy diesel industry is the American Society of Testing and Materials (ASTM) specifications for Biodiesel and Biodiesel Blends. The two categories that are in need of immediate improvement to …

Genetic And Phenotypic Characterization Of Plant Pathogen Inhibitory Streptomyces Isolates, Uylissa A. Rodriguez

Theses and Dissertations - UTB/UTPA

Streptomyces are Gram-positive, filamentous bacteria that are readily isolated from soil and produce diverse secondary metabolites such as pigments and antibiotics. A survey of indigenous soil microbes from Rio Grande Valley agricultural soils revealed several isolates with broad inhibitory abilities against a range of soil-borne plant pathogens. The goal of this study was to characterize eleven of these potential biocontrol isolates both biochemically and genetically. Nutrient utilization profiles, 16S rDNA sequencing, and the presence of genes involved in antibiotic biosynthesis pathways (strBl, strR, strF, strN, strS and KS) on plasmids or the chromosome were investigated. Nutrient utilization profiling revealed that …

Plant Growth Regulator Sprays And Girdling: Potential Horticultural Techniques To Increase Fruit Retention And Yield Of Longan (Dimocarpus Longan Lour.) Trees In California, Leila Anne Graves

Master's Theses

Abstract Plant Growth Regulator Sprays and Girdling: Potential Horticultural Techniques to Increase Fruit Retention and Yield of Longan (Dimocarpus longan Lour.) Trees in California Leila Graves June 2009 The longan is a subtropical fruit tree whose popularity is growing quickly among American consumers, and thus, could become a lucrative niche market for California growers. Trees planted as part of an initial variety trial conducted in commercial California orchards are beginning to bear fruit. However, fruit retention and yields are low due to excessive abscission during early fruit set. Horticultural techniques, such as plant growth regulator (PGR) sprays and girdling, often …

An Examination Of The Correlation Between Shoot Apical Meristem Size And Leaf Heterophylly In Pisum Sativum, Cynthia Mary Halfman

Undergraduate Honors Thesis Collection

This study is a quantitative examination of the ramifications of leaf development as influenced by the size of the shoot apical meristem. I wish not to delve into a genetic examination of the shoot apical meristem but rather into the possible correlation between the apical meristem size and leaf heterophylly. If changes in shoot apical meristem size influence heterophylly in leaves, then as shoot apical meristem changes, leaf characteristics will change. This change may result from two different relationships.

Goatsrue (Galega Officinalis) Seed Biology, Control, And Toxicity, Michelle Oldham

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Goatsrue is an introduced perennial plant that has proven to have great invasive potential, leading to its classification as a noxious weed in many states and at the federal level. This research focused on seed biology, herbicide control, and toxic dynamics of goatsrue. Physical dormancy of mature goatsrue seed was tested through scarification using sulfuric acid with exposures of up to 60 minutes resulting in 100% germination. Comparison of dormancy for 26-year-old and 6-month-old goatsrue seed indicated aged seeds had reduced dormancy levels compared to newly harvested seeds, but had similar viability. Goatsrue seedling emergence was inversely related to burial …

Overseeded Bermudagrass Spring Trasition Response To Mowing Height, Nitrogen Rate, Sulfonylurea Herbicide, And Allelopathy, Raymond Mccauley

All Theses

Hybrid bermudagrass [Cynodon transvaalensis Burtt-Davey x C. dactylon (L.)
Pers.] is the preferred turf for golf courses and athletic fields across the southern United
States because of its dark green color, fine texture, good wear and drought tolerance, and
excellent recuperative rate. Despite its many attributes, bermudagrass goes dormant and
turns an unsightly brown color when soil temperatures fall below 10-13oC (50-55super>oF).
Perennial ryegrass (Lolium perenne L.) is often overseeded into bermudagrass in the fall
to sustain acceptable turf quality through the spring months. However, perennial ryegrass
aggressively competes with the bermudagrass for resources in the spring and potentially …

Evaluation Of Herbicide Efficacy As Influenced By Adjuvant And Nozzle Type, Catherine L. (Grissom) Ansolabehere

Master's Theses

White clover (Trifolium repens) is a common and difficult weed to control in turfgrass as it is a highly visible and unsightly weed that disrupts the uniformity of the turfgrass surface. This weed is a serious problem in the turfgrass industry in California and there is a need for better methods of control. With more regulations on pesticides and less information about efficient application techniques, controlling white clover with available herbicides can be difficult.

Compatibility trials were conducted during the summer of 2005 to determine the compatibility of the herbicides and adjuvants planned for use in subsequent greenhouse and field …

Biology And Ecology Of Wild Radish (Raphanus Raphanistrum), Mayank Malik

All Dissertations

Wild radish ( L.), a facultative winter annual is a troublesome weed in small grain crops of the Southeastern United States. Besides being a weed, it may also be used as a cover crop for weed management due to its production of glucosinolates. Studies were conducted to evaluate the biology and ecology of wild radish as well as its glucosinolate production and its weed management possibilities.
Wild radish emerging in fall months formed a rosette of leaves which aided its winter survival. Plants emerging from December through March that did not form a rosette had minimal survival. Wild radish life …

Investigation Of Plant Water Use In The Great Basin, Nv, Benjamin Conrad

UNLV Theses, Dissertations, Professional Papers, and Capstones

Global climate change in addition to a growing population can have a strong impact on our natural resources. In particular, cities in the semi-arid and arid southwestern US are currently faced with the challenge of providing sustainable fresh water to a growing population. In Las Vegas, dwindling water levels in Lake Mead have forced water managers to seek water resources from Spring Valley and Snake Valley, NV, which are located 402 km north of the city. The goals of this research were to investigate the water use of shrubs located in these valleys by using a large aperture scintillometer (LAS) …