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Light Intensity Control For Plc-Based Hydroponic Demonstration System, Christian Hitt

Biological and Agricultural Engineering Undergraduate Honors Theses

In order to demonstrate a skill set obtained through the University of Arkansas Biological Engineering, a group of students and I developed a hydroponic system where plants could be grown in a chamber. System parameters such as air quality, irrigation, and lighting were controlled by a Programmable Logic Computer (PLC) and an array of sensors and actuators. Each student focused on a certain aspect of this system, mine being the lighting. Developing this system involved researching the relationship between light intensity and plant growth, designing a system to suspend the lights above the growth chamber, and develop a system to …

An Analysis Of The Pollinators Of Echinacea Purpurea In Relation To Their Perceived Efficiency And Color Preferences, Carmen Black

Honors Theses

This study aimed to better understand how insects interacted with species of Echinacea in Tennessee and specifically their preference to floral color. Based on previous studies I expected the main visitors to be composed of various bees, beetles and butterflies. Based on previous studies, I hypothesized that most bees (especially social bees) would most likely pollinate the purple/violet morphs of the flower versus the white morph. I also expected the bees would have the most visits to the coneflowers versus any other taxonomic group. I believe bees to be the majority of pollinators based upon the results of Stucky, Gadd, …

Examining The Invasion Of A Bush Honeysuckle Using Climate Analysis, Andrew Palmer

Biological Sciences Undergraduate Honors Theses

Within the study of invasive plants, particular importance is placed on elucidating the mechanisms by which these plants proliferate and dominate within their introduced ranges. Several theories have been advanced to explain these invasions, each with different implications for the predicted range of invasive plants. Recent studies have provided support for the application of several invasion theories to Lonicera maackii, or what is more commonly referred to as bush honeysuckle. This species provides a unique opportunity to examine the efficacy of these theories in explaining the range expansion of invasive plants. L. maackii is endemic to eastern Asia, but …

Winners And Losers In Reforestation Efforts In The Lower Rio Grande Valley Of Texas, And The Predictive Power Of Xylem Anatomy On Long-Term Growth And Survival, Clifton F. Albrecht

Theses and Dissertations

Reforestation has been ongoing in the Lower Rio Grande Valley annually since the 1980s, and to date over 6400 ha of land has been reforested in this area. However, there has been little subsequent study of the change and development of those forests as they mature. This thesis consists of two, interrelated, studies: (1) surveys of a five-site chronosequence of restored forests and (2) quantification of xylem anatomical traits of a subset of species present at the reforestation sites. Surveys showed a consistent reduction in species diversity and stem number density on the landscape, and identified a suite of species …

Understanding The Ecological Role, Population Dynamics, And Geographic Distribution Of Manihot Walkerae, Gisel Garza

Theses and Dissertations

Walker’s Manihot, Manihot walkerae Croizat (Euphorbiaceae), is an endangered plant that is endemic to the Tamaulipan thornscrub ecoregion. Understanding M. walkerae’s geographic distribution, populations, and species interactions can provide essential information for the development of sound conservation strategies. To this aim, I asked the following questions: 1) What is the potential geographic distribution for M. walkerae? and, will it be affected by climate change? 2) Using global and regional extinction risk assessments, what is the extinction risk category for M. walkerae after incorporating species distribution models? 3) What do natural history observations reveal about M. walkerae’s population …

Physical And Chemical Defense Mechanisms In Aloe Barbadensis Against Insect Herbivores, Zachary Johnson

Theses and Dissertations

Chapter 1: This chapter provides an overview of insect herbivore impacts on plants and plant defense mechanisms to combat them. I particularly focused on physical and chemical defenses in the broader sense.

Chapter 2: This chapter describes the experiments that showed the effects of extracts from Aloe barbadensis on the growth and development of tobacco hornworm (Manduca sexta) and fall armyworm (Spodoptera frugiperda), model herbivores used to understand herbivore growth and plant defenses. This study shows that extracts from the Aloe differentially affected the growth and development of M. sexta and S. frugiperda. This chapter …

Unravelling The Role Of Pgpr "Pseudomonas Fluorescens" In Semi- Arid Soils Of The Rio Grande Valley, Mandip Tamang

Theses and Dissertations

Chapter 1: In this chapter, we have provided a review on the components of rhizosphere engineering and the potential use of PGPR and its challenges to serve as an efficient component for sustainable agriculture.

Chapter 2: In this chapter, we isolated 35 different strains of a PGPR, Pseudmonas fluorescens and characterized various plant growth promoting traits such as production of ammonia, protease, Indole acitic acid (IAA), 1-aminocyclopropane-1-carboxylate deaminase (ACC) deaminase, ammonia, hydrogen cyanide (HCN), and souliblization of zinc and phosphate.

Chapter 3: In this chapter, we tested the influence of plant beneficial soil microbe, P. fluorescens, on the growth and …

Not All Pollinator Gardens Are Created Equally: Determining Factors Pertinent To Improving Pollinator Garden Effectiveness, Travis Watson

Electronic Theses and Dissertations

Increasing evidence documenting the decline of insect populations, resulting from increasing human disturbances has resulted in efforts to establish pollinator gardens to provide additional resources for insect populations. However, our understanding of biotic and abiotic garden characteristics important for attracting and sustaining pollinator diversity is limited. Here, we evaluated 17 pollinator gardens to evaluate the effect of five biotic and three abiotic garden characteristics on pollinator species richness, abundance, and proportional representation of four pollinator functional groups. Plant species richness positively influenced pollinator richness and negatively influenced flower visitation. Bombus proportional abundance responded to several variables (distance to vegetation, plant …

Economic Feasibility Of Sub-Surfaced Poultry Litter, James Timothy Stults

Graduate Theses and Dissertations

Livestock producers routinely spread fertilizer or broadcast poultry litter to improve forage production. With poultry litter widely available across the Southeastern United States and a cheaper source of plant nutrition than fertilizer when proximal to application sites, the novel application of litter below the soil surface, while costly, allows for greater nutrient retention than broadcasting. Since quantifying costs and benefits of sub-surface litter application (SSLA) is complex, we develop and present a spreadsheet tool for automated comparison between SSLA, fertilizer, and broadcasted litter for user-specific scenarios involving equipment choices (new, used, custom), desired nutrient needs for crops grown, litter nutrient …

The Importance Of A Multidisciplinary Approach To Public Health: Addressing Food Insecurity Through A Biological And Sociological Lens, Chloe Grant

Honors Theses

Plants can sense the change of 1 ^oC in their growth environment and thus global climate change has a great impact on plant growth and development. The phenomenon that warm non-stress temperatures promote stem and petiole elongation, as well as leaf hyponastic growth, is collectively known as thermomorphogenesis. While it is known that the basic helix-loop-helix (bHLH) transcription factor PIF4 is highly inducible by temperature elevations and controls thermomorphogenesis in dicots (e.g., Arabidopsis thaliana), the molecular mechanism underlying thermomorphogenetic growth in monocots is not clear. In this study, I identify PIF4 orthologs in several economically important monocotyledonous species and …

Fatty Acid Composition Of Forages And Their Effect On The Fatty Acid Composition In Beef Cattle, Britney G. Allen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study focused on how diet changes the rumen microbiome in the cattle and the effects of that on the long chain fatty acids (LCFA) by microbes in the rumen, and on the short chain fatty acids (SCFA) these microbes produce from feed carbohydrates like fiber and starch. The abundance of bacteria belonging to the phyla Tenericutes and Proteobacteria increased in response to high-fiber or high-starch diets, respectively. The production of two SCFA was positively correlated with the presence of increased Tenericutes (acetate) and Proteobacteria (propionate). A greater acetate to propionate ratio is associated with elevated production of enteric methane …

The Influence Of Singlet Oxygen And Loss Of Function Of Fatty Acid Desaturase 7 In The Chloroplast On Aphid Resistance In Arabidopsis Thaliana, Hillary Donna Fischer

Graduate Theses and Dissertations

Fatty Acid Desaturase 7 (FAD7) is a chloroplast-localized enzyme that alters the fatty acid content of photosynthetic membranes, and that negatively regulates plant defenses against aphids. Previous studies in the model organism Arabidopsis (Arabidopsis thaliana) have shown that loss-of-function mutations in FAD7 decrease population growth of the green peach aphid (GPA; Myzus persicae Sulzer). This study further characterized the effects of a fad7 null mutant on aphids, and investigated the role of reactive oxygen species (ROS), including singlet oxygen (1O2), in plant responses to aphid resistance in fad7 as well as in wild type plants and a mutant with heightened …

Evaluation Of Nutrient Solutions Produced From Aqueous Extracts And Decomposition Products Of Organic Waste Materials On The Plant Growth Performance In Hydroponics, Noura Said Al Nuaimi

Theses

Hydroponic plant production involves the cultivation of plants in absence of soil. In this system, the supply of the plant root with water and nutritional elements occurs via a nutrient solution made of inorganic salts. Hydroponic plant cultivation often achieves higher yields, water use efficiencies and quality of crops compared with soil production. In addition, it renders the farming system independent from soil properties. However, the currently available systems rely on the steady input of non-renewable inorganic salts. Unlike soil-based systems, hydroponics, so far, do not offer feasible opportunities for recycling nutritional elements from within crop residues or organic waste …

Suppression Of Erecta Signaling Impacts Agronomic Performance Of Soybean (Glycine Max (L) Merril) In The Greenhouse, Yasmin Vasques Berchembrock, Flavia Barbosa Silva Botelho, Vibha Srivastava

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

The ERECTA (ER) family of genes, encoding leucine-rich repeat receptor-like kinase (RLK), influences complex morphological and physiological aspects of plants. Modulation of ER signaling leads to abiotic stress tolerance in diverse plant species. However, whether the gain in stress tolerance is accompanied with desirable agronomic performance is not clearly known. In this study, soybean plants potentially suppressed in ER signaling were evaluated for the phenotypic performance and drought response in the greenhouse. These plants expressed a dominant-negative Arabidopsis thaliana ER (AtER) called ΔKinase to suppress ER signaling, which has previously been linked with the tolerance to water …

Interactive Effects Of Soil And Browsing On Big Sagebrush: Implications For Restoration Success, Kyle Nehring

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

Heterogeneity in landscape conditions (e.g., soil types) precludes a “one size fits all” management strategy across large landscapes. New management approaches that explicitly account for heterogeneous landscapes (and the variable conditions therein) will be required to maintain habitat quality. In particular, we require an improved mechanistic understanding of how the outcomes of conservation and restoration actions are contingent upon a) contextual abiotic factors (e.g., moisture availability mediated by soils and precipitation) and b) their interactions with biotic factors (e.g., browsing wildlife).

We propose to answer fundamental questions about how big sagebrush (Artemisia tridentata), the foundational species for sagebrush …

Short-Term Effects Of Winter Cover Crops On Soil Properties, Yield, And Partial Returns In A No-Tillage Soybean Rotation, Drew Dillon Kirkpatrick

Graduate Theses and Dissertations

Cover crops have the potential to provide many benefits including weed suppression, erosion control, and improvements to soil quality. These benefits can be affected by species, biomass accumulation, and management practices. Although large amounts of biomass are good for maximizing benefits, it can result in problems for establishing the subsequent crop. Soybean [Glycine max (L.) Merr.] accounts for over 50% of Arkansas crop hectares annually; therefore, understanding the effect that a cover crop can have on the following soybean crop is crucial to the successful implementation of cover crops within the state. A study was established to evaluate winter cover …

Screening And Breeding Soybean For Flood Tolerance, Maria Roberta De Oliveira

Graduate Theses and Dissertations

Waterlogging can be detrimental to soybean [Glycine max (L.) Merr.] growth and development, with effects ranging from chlorosis and stunting to yield loss and plant death. Soybean responses to, and the effects of, waterlogging are dependent on the growth stage of the plant at the initiation of waterlogging. The objectives of this study were: (1) to assess the effectiveness of Genomic Selection (GS), Marker Assisted Selection (MAS) and Phenotypic Selection for flood tolerance at the progeny row stage as compared to random selection, for the development of high-yielding flood-tolerant lines; and (2) to compare field-screening and hydroponic greenhouse screening methodologies …

Spore Dispersal Of Slime Molds And Higher Fungi Via Animal Vectors, Courtney Trimble

Graduate Theses and Dissertations

Myxomycetes and dictyostelids are Amoebozoans that are cosmopolitan inhabitants of a variety of habitats, particularly forest environments. Both groups reproduce using spores which are primarily dispersed via wind in myxomycetes but this characteristic poses a problem for dictyostelids. The spores of dictyostelids are incased in a mucilaginous matrix that makes wind ineffective except in exceptional cases. It has been suggested that animals such as birds may play an important yet understudied role in the dispersal of these organisms. This study investigated how animals could potentially serve as vectors for spore dispersal of dictyostelids and myxomycetes with some limited data obtained …

Crop Response To Low-Dose Dicamba, Mason Castner

Graduate Theses and Dissertations

The introduction of dicamba-resistant (DR) soybean [Glycine max (L.) Merr.] and cotton (Gossypium hirsutum L.) followed by a label allowing over-the-top applications of dicamba in the 2017 provided growers an additional option for broadleaf weed control. Because non-DR soybean is sensitive to low concentrations of dicamba, postemergence dicamba applications present growers choosing to plant non-DR soybean with concerns of damage from off-target movement through physical drift and volatilization of the herbicide as well as tank-contamination from prior dicamba application. Consequences of low-dose dicamba exposure on sensitive vegetative and reproductive soybean have been well researched, but little is known regarding the …

Transcriptional Activation Of Phytochrome-Interacting Factor 4 Is A Conserved Mechanism Of Thermomorphogenesis In Dicotyledenous Plants, Caroline Clutton

Honors Theses

In the model dicotyledonous plant Arabidopsis thaliana, the basic helix-loop-helix (bHLH) transcription factor Phytochrome-Interacting Factor 4 (AtPIF4) plays a central role in regulating the ambient temperature-regulated hypocotyl growth response. Warm temperatures induce AtPIF4 transcription and the accumulated AtPIF4 promotes thermomorphogenesis by enhancing the expression of a group of growth-related genes. However, whether this thermo-induced growth response is universal, and more importantly, whether there is a conserved thermomorphogenetic mechanism shared in dicots is largely unknown. Here we show that higher ambient temperatures promote the hypocotyl growth in four other dicotyledonous plants, including Brassica rapa, Camelina sativa, Nicotiana benthamiana …

A Baseline Documentation Report For The Delta Wind Birds Sky Lake Nature Reserve, James Dubberly

Honors Theses

The purpose of this baseline documentation is to conduct a report on our subject property and discuss the findings. A conservation easement is established by upholding a certain standard of a property’s current condition which makes a baseline documentation necessary for an easement to be enacted. Baseline documentation reports are used as a resource to monitor and enforce the legal agreements of the conservation easement. The subject property is currently owned by the Delta Wind Birds organization. In our scenario, this documentation report will serve to aid in the conversion of our subject property into a conservation easement in which …

The Flowering Dynamics And Seedset Of Cichorium Intybus L. Cv. Puna, Yongfeng Han, Chengbin Tang, Mouqiong

IGC Proceedings (1977-2023)

No abstract provided.

The Effects Of Time Of Application Of Nitrogen On Seed Yield, Efficiency Of N Fertilizer Use And Apparent N Fertilizer Recovery Of Russian Wildrye [Psathyrostachys Juncea (Fisch.) Nevski], Jianguo Han, Yunwen Wang, Shengquan Jiang, Bo Liu

IGC Proceedings (1977-2023)

No abstract provided.

Seed Yield Formation Of Festulolium And Lolium X Boucheanum Under Climatic Condition Of Latvia, Iveta Gutmane, Aleksandr Adamovich

IGC Proceedings (1977-2023)

No abstract provided.

Callus Induction And Plant Regeneration Of Poa Pratensis 'Nasu' Seeds Carried By China Recoverable Satellite Shijian‐8, Yinghua Guo, Lei Han, Guansheng Ju, Zhenyuan Sun

IGC Proceedings (1977-2023)

No abstract provided.

Detection Of European Aspen (Populus Tremula L.) Based On An Unmanned Aerial Vehicle Approach In Boreal Forests, Anton Kuzmin, Lauri Korhonen, Sonja Kivinen, Pekka Hurskainen, Pasi Korpelainen, Topi Tanhuanpää, Matti Maltamo, Petteri Vihervaara, Timo Kumpula

Aspen Bibliography

European aspen (Populus tremula L.) is a keystone species for biodiversity of boreal forests. Large-diameter aspens maintain the diversity of hundreds of species, many of which are threatened in Fennoscandia. Due to a low economic value and relatively sparse and scattered occurrence of aspen in boreal forests, there is a lack of information of the spatial and temporal distribution of aspen, which hampers efficient planning and implementation of sustainable forest management practices and conservation efforts. Our objective was to assess identification of European aspen at the individual tree level in a southern boreal forest using high-resolution photogrammetric point cloud …

Tannin Contents Of Sainfoin (Onobrycyhis Viciifolia Scop) Grown With Or Without Irrigation And Harvested At Different Growth Stages, Y. Wang, T. A. Mcallister, S. N. Acharya, K. H. Ominski, D. O. Krause

IGC Proceedings (1977-2023)

No abstract provided.

Implications Of Excess Nitrogen For Intake, Diet Choice And Production Of Sheep Fed Temperate Pastures, Garry C. Waghorn, G. P. Cosgrove

IGC Proceedings (1977-2023)

No abstract provided.

Sample Preparation Affects Non Structural Carbohydrates In Alfalfa, Gaëtan F. Tremblay, Annick Bertrand, Yves Castonguay, Gilles Bélanger, Sophie Pelletier, Réal Michaud

IGC Proceedings (1977-2023)

No abstract provided.

Nitrogen Intake And Utilisation Pattern In The Digestive Tract Of Sheep Grazing Four Subtropical Foggages, Willem A. Van Niekerk, Abubeker Hassen

IGC Proceedings (1977-2023)

No abstract provided.