Digital Commons Network^™

The Influence Of At-Planting Insecticide Treatments On Tobacco Thrips, (Thysanoptera:Thripidae), And Reniform Nematode, (Tylenchida:Hoplolaimidae), In Conventional And Thryvon Cotton Systems, Walker Brett Farmer

Theses and Dissertations

One of the objectives of this research was to evaluate the need for an additional imidacloprid seed treatment on ThryvOn^® (Bayer Crop Science^®, St. Louis, MO) cotton to effectively manage tobacco thrips, Frankliniella fusca (Hinds). While evaluating thrips densities and damage ratings, ThryvOn cotton continued to display reduced damage and thrips populations than non-ThryvOn. Thrips populations and damage ratings were consistently reduced when incorporating a higher rate of imidacloprid, but they were not reduced enough to justify the higher rates of imidacloprid. Another objective of this research was to evaluate the impact of aldicarb (AgLogic Chemical^{® …}

Insights Into The Challenges Posed By Climate Change And Land Competition To Brazil’S Midwest Pulpwood Market, Roberto Hajime Sant Anna Kimura

Theses and Dissertations

I investigated the effect of climate change in one of the few expanding markets in the world in Brazil. In the last decades the demand for pulpwood increased from zero to 11 million tons, leading to an expansion of 700 thousand hectares of Eucalyptus plantation. In 2024, a new mill will start operating increasing the consumption of wood fiber by 8.2 million tons (+49%). I used mathematical programming to investigate how different scenarios of productivity and land will affect the market. My results showed that around 946,000 hectares (+124%) of additional timberland will be necessary in the upcoming decades. The …

Isolation And Culture Of Epichloё For Reinfection Of Endophyte-Free Southeastern Wildrye (Elymus Glabriflorus), Bryna Joann Haile

Theses and Dissertations

Mutualistic relationships between endophytic fungi and grasses have shown to improve the hardiness of the host. This relationship is common in grasses, including North American native grasses that are important in both forage and grassland ecosystems. Elymus species, such as Canada wildrye (CWR), commonly host the endophytic fungi, Epichloё, while southeastern wildrye (SEWR) may not. In this study, seed of CWR and seed and leaves from local SEWR were assessed for endophyte infection. Infection status was confirmed via histological analysis of seed squashes and leaf peels. Presence/absence of endophyte was determined by scanning for mycelia within seed and between leaf …

Pre-Emergence Herbicide Programs For Weed Control In Soybean (Glycine Max) And The Effect Of Rainfall Amount On Herbicide Activity, Caleb Knox Meyer

Theses and Dissertations

Preemergence (PRE) herbicides are used to control weeds and reduce pressure on postemergence (POST) herbicides. However, knowledge of length of control each herbicide provides, as well as the amount of activation rainfall required for adequate weed control, is unknown in Mississippi soybean production. Twenty-one PRE applied soybean herbicides were evaluated for their duration of residual control for five weeks over twelve site years on three weed species from 2021-2022. Some differences in control following herbicide application used on certain weed species were observed at different times. However, most PRE herbicides resulted in adequate (greater than or equal to 90%) control …

Evaluating The Role Of The Bovine Vaginal Microbiome In Neonatal And Maternal Health Outcomes, Riley D. Messman

Theses and Dissertations

The dam vaginal microbiota is the first major microbial inoculating community within the neonate. The composition of the dam vaginal microbiota has implications in calf commensal microbiota development. Alterations of the dam microbial community prior to parturition could alter inoculating communities and immune responses in both the dam and calf. Thus, authors aimed to elucidate the microbial community composition of the bovine dam vaginal and calf nasal microbiota post-partum after utilizing betadine lavages (BL). The dam vaginal and calf nasal microbial communities and immune responses were evaluated at 0-, 15-, 30- and 60-day post-partum. Microbiota composition of the dam haircoat, …

Integrating Weed-Suppressive Cotton Chromosome Substitution Lines And Cover Crops For Sustainable Weed Management In Cotton Production Systems., Alyssa Lea Miller

Theses and Dissertations

Weeds pose a challenge to cotton production, and herbicides have been the primary means of control. However, there is growing concern over weed resistance to herbicides. To address this issue, we evaluated three cover crop species and six cotton accessions for weed suppression. The study found that hairy vetch, wheat, and B16 cotton CS line effectively suppressed Amaranthus species, while MNTN 4-15, B16, hairy vetch, and wheat were correlated with the highest cotton yield. Cover crops were also analyzed for chlorogenic acid content, with wheat, MNTN 4-15, and hairy vetch producing the highest amounts. The greenhouse tray study showed that …

Upland Cotton And Nematodes: An Analysis Of Historical Resistance, Upcoming Threats, And Co-Inoculation Effects, Amanda Gaudin

Theses and Dissertations

Upland cotton (Gossypium hirsutum ) is an important fiber crop grown throughout the southern United States. Plant-pathogenic nematodes are worm-like animals that feed on the roots of most agronomic crops, including cotton. The southern root-knot nematode (Meloidogyne incognita, RKN) and the reniform nematode (Rotylenchulus reniformis, RN) cause significant yield losses in cotton every year. Current sources of resistance are effective but limited, therefore historical screenings of cotton accessions were revisited in search for novel resistance sources. None were identified but many of the screened accessions possessed markers of known root-knot nematode and reniform nematode resistance. …

Evaluation Of Italian Ryegrass And Palmer Amaranth Control In Mississippi, Johnson Harris Hughes

Theses and Dissertations

Italian ryegrass is a problematic weed in Mississippi corn production due to the development and proliferation of glyphosate resistance. Studies were conducted to assess Italian ryegrass control prior to planting using herbicides. Effects of fall and spring applied burndown herbicide applications for Italian ryegrass control and subsequent corn grain yield were investigated at the R.R. Foil PSRC in Starkville, MS, at the Coastal Plain Experiment Station in Newton, MS, and the Black Belt Experiment Station in Brooksville, MS on soil textures ranging from sandy loam to silt clay loam. A fall preemergence (PRE) application of S-metolachlor + metribuzin followed …

Genome-Wide Association Study For Agronomic Traits In Bermudagrass (Cynodon Spp.), Lovepreet Singh

Theses and Dissertations

Bermudagrass (Cynodon spp.) breeding and cultivar development is hampered by limited information regarding its genetic and phenotypic diversity. A germplasm collection of 206 bermudagrass accessions from 29 countries was genotyped with high-throughput genotyping-by-sequencing technique. Genomic diversity in this diverse germplasm panel was assessed with multifaceted approaches including population structure, phylogenetic analysis, principal component analysis, and genetic diversity parameters. This study revealed substantial genetic variation in the Cynodon accessions, demonstrating the potential of this germplasm panel for further genetic studies and cultivar development in breeding programs. Another critical issue in turfgrass breeding is the lack of information regarding the genetic …

Marginal Agricultural Land Identification In The Lower Mississippi Alluvial Valley, Prakash Tiwari

Theses and Dissertations

This study identified marginal agricultural lands in the Lower Mississippi Alluvial Valley using crop yield predicting models. The Random Forest Regression (RFR) and Multiple Linear Regression (MLR) models were trained and validated using county-level crop yield data, climate data, soil properties, and Normalized Difference Vegetation Index (NDVI). The RFR model outperformed MLR model in estimating soybean and corn yields, with an index of agreement (d) of 0.98 and 0.96, Nash-Sutcliffe model efficiency (NSE) of 0.88 and 0.93, and root mean square error (RMSE) of 9.34% and 5.84%, respectively. Marginal agricultural lands were estimated to 26,366 hectares using cost and sales …

Activity Level Of Helicoverpa Armigera Nucleopolyhedrovirus (Hearnpv) And Feeding Habits Of Helicoverpa Zea Larvae After Ingestion Of Hearnpv In Mississippi Soybean, Judge Tyler Fortenberry

Theses and Dissertations

HearNPV was applied to a soybean field and evaluated for residual efficacy at different time intervals (0, 12, 24, 36, 48, and 72 hours) after application in laboratory bioassays with treated leaves. Larval mortality was rated at five, seven and twelve days after larval infestation. Larval mortality increased as the number of days after infestation increased. To evaluate the feeding habits of Helicoverpa zea at the 2^nd and 3^rd instar, HearNPV exposed larvae and untreated larvae were weighed at zero (before diet exposure), four, and seven days. At four days after exposure, larval weight gain of …

Evaluation Of Warm Season Vegetables Using Sustainable Production Practices, Jacob Arthur

Theses and Dissertations

Sustainable practices were evaluated for the production of two warm season vegetable crops, tomato and chile peppers. The first study investigated the plant vegetative growth, fruit production timing, yield components and fruit quality of three hybrid and three heirloom tomato cultivars grown in a high tunnel using grafted and non-grafted plants. Grafting the selected tomato cultivars with the two rootstock types did not alter total marketable yield of any cultivar, but affected overall stem diameter, fruit color, and β-carotene concentrations of tested tomato cultivars. The second study evaluated the plant growth, yield, and fruit quality of nine heirloom chile pepper …

Metagenomic Analysis Of Root-Associated Microbiome Of Healthy And Taproot Decline-Affected Soybeans And Identification Of Healthy Soybean Root Endophytes With Protective Activity Against The Causal Agent, Xylaria Necrophora, Uyen Wesser

Theses and Dissertations

Plant roots are associated with a diverse microbial community of bacteria and fungi. The root microbiome communities associate with the root surface or penetrate the superficial layers of root tissues. It is of high agronomic interest to characterize root microbiomes and identify microbes with beneficial effects on plant defense against pathogens. Soybean taproot decline (TRD) is an emerging soil-borne disease caused by a fungus classified as Xylaria necrophora, challenging to control and with devastating effects on yield. Our group has initiated a study of the soybean root microbiome with three primary experiments: (I) perform a comparative study of root …

United We Stand? Investigating The Impact Of Unified Dues Agreements Between State And National Career & Technical Education (Cte) Professional Organizations On Cte Funding In The Southern States, Justin Ryan Hall

Theses and Dissertations

Career and Technical Education (CTE) teachers have long been active in lobbying the federal and state governments in support of CTE through their professional organizations, but these are not traditionally considered interest groups. This study sought to determine if the formal relationships—dues agreements—between the two largest national professional organizations, and their state affiliates had an impact on state funding for CTE. The impacts of professional organization unity, membership rates, and lobbying expenses on state-level CTE funding were analyzed through the lens of interest group theory, a subfield of political science. Within this population (N = 13), 1) a link …

The Effects Of Glyphosate Salts And Volatility-Reducing Agents (Vra) On Dicamba Volatility, Nicole Glenn

Theses and Dissertations

Dicamba is often tank mixed with glyphosate to increase herbicidal efficacy but may contribute to off-target movement (OTM). In recent years, volatilization has become problematic for dicamba-containing herbicides, resulting in increased regulatory requirements necessitating the use of volatility-reducing agents (VRA) for application. Research was conducted in 2021 and 2022 using low tunnels in a field environment and humidomes in a greenhouse environment to further assess how glyphosate salts and VRAs affect dicamba volatility. Our data indicate that the inclusion of glyphosate to dicamba can increase dicamba volatility, depending on the glyphosate salt used. The inclusion of the evaluated VRAs will …

Evaluation Of Novel Litter Amendments For Use In The Commercial Broiler Industry, Jorge A. Urrutia

Theses and Dissertations

Poultry litter amendments (LA) are commonly used to maintain good litter quality; the most common ones; are acidifiers. However, concern over the lifespan of LA acidifiers (d) and corrosive nature revealed a need for alternative LA. Products of interest include biochar (BC), superabsorbent polymers (SAPs), and alum mud (AM). Experiment 1 was a screening study (n=17 treatments, no birds) conducted to determine the optimal application rate/method of BC, SAPs, and AM vs.commercial LA and a control. Most SAPs treatments measured metrics may be similar (i.e., bacteria, water activity) or better (pH) vs. commercial LA (PLT). High inclusions of novel LA …

The Employability Of State Ffa Degree Recipients In Alabama, Kailee D. Johnson

Theses and Dissertations

Many high schools have shifted from comprehensive graduation exams to a focus on College and Career Readiness. A common method used to determine when a student is college and career ready is a Career Readiness Indicator (CRI). Many CRIs demonstrate a benchmark learning goal for students. Among academic-based CRIs are Career and Technical Education (CTE) industry credentials. Credentials are just one way that agriculture classrooms contribute to student success. This study compiled existing research on CRIs and employability skills in CTE students to determine how the State FFA Degree could potentially fit into this category as well as highlight specific …

Effects Of The In Ovo Administration Of The Poulvac E. Coli Vaccine In Layer Hatching Eggs On Hatchability, Hatchling Characteristics, And Early Posthatch Chick Performance, Lauren L. Lindsey

Theses and Dissertations

Avian Pathogenic E. coli can lead to infections in laying hens and wide-spread economic problems in the table egg industry. A vaccine widely used to combat APEC is the Poulvac E. coli vaccine, which is normally applied via spray vaccination. Application of this vaccine via in ovo injection has not been examined. The purpose of this series of studies was to determine the effects of injecting 50 μL of different dosages of the PECV into Hy-Line W-36 layer hatching eggs on the hatchability and characteristics of the hatchlings, and on the livability and characteristics of the chicks through 21 d …

The Relationship Between Leadership Preference Of County Level Personnel Within University Of Missouri Extension And Their Level Of Employee Engagement, Jason C. Morris

Theses and Dissertations

The purpose of this study was to describe the perceived leadership style of the University of Missouri Extension Service county staff and their level of engagement and study the relationship between variables. Administrators with University of Missouri Extension Service can utilize this information to better serve Extension Staff and ultimately people throughout the state of Missouri.

The Vannsimpco Leadership Survey was used to measure the perceived leadership style of county level staff. The Utrecht Work Engagement Scale (UWES) was used to measure work engagement on three constructs: vigor, absorption, and dedication engagement. Demographic characterizes of county level staff was also …

Sustainable Sidedress Nitrogen Applications For Early Corn And Cotton Crops Using Small Unmanned Aerial Systems, James Nolan Parker

Theses and Dissertations

Nitrogen run-off from agriculture have been linked to human health problems on a global level. Large-scale conventional producers struggle to redefine themselves as sustainable because reducing nitrogen (N) inputs without justification or validation may lead to severe profit losses. Small unmanned aerial systems (sUAS) sensing may allow for decreased N runoff. Failure to address this problem will exacerbate already excessive N runoff into the Mississippi River and beyond. The purpose of this study was to reduce fertilizer N input using sUAS technology to assess crop canopy needs. In 2020 and 2021, variable rate nitrogen (VRN) side-dress N application maps were …

The Impacts Of The Covid-19 Pandemic On The Food Security Of Mississippians, Hannah Noel Irwin

Theses and Dissertations

Mississippi leads the United States in food insecurity, with 15.3% of Mississippians experiencing food insecurity in a given year. To determine the impacts of the COVID-19 pandemic on the food insecurity of Mississippians, a survey containing the USDA Household Food Security Questionnaire was distributed to adult Mississippi residents. By employing the USDA Household Food Security Scale and the Foster-Greer-Thorbecke Methodology, this study finds that the food insecurity rate, food insecurity gap, and squared food insecurity gap have worsened in Mississippi since the beginning of the COVID-19 pandemic. Additionally, this study finds that households which were food insecure prior to March …

Assessing Virtual Free-Choice Agricultural Learning: A Mixed Methods Approach, Richard John Kennedy

Theses and Dissertations

Since the mid-19th century, agricultural museums and living history sites, first in Scandinavia and then in the United States and Canada, have provided historical, cultural, and, sometimes, scientific information about farming to visitors. Many of these visitors have been school children on field trips. Assessment of this learning, however, has been scant, particularly within the free-choice style inherent in these types of educational venues. At the same time, assessment of free-choice learning, often analyzed through the Contextual Model of Learning (Falk & Dierking 2000), has taken place at educational sites like zoos, natural history museums, and science centers. This study, …

Determining Residual Control And Systemic Activity Of Commonly Used Insecticides In Soybean And Cotton, Jacob H. Smith

Theses and Dissertations

Chemical control is a critical component of integrated pest management in cotton and soybean production. Residual efficacy of foliar insecticides can be highly variable and difficult to quantify due to several factors. The purpose of this research was to determine residual control and concentrations in flowering structures of commonly used insecticides. This research focused on the concentrations of active ingredient within the plant as well as efficacy over time. Previous research suggested chlorantraniliprole had a long residual and was highly lethal on corn earworm up to 28 days after treatment (DAT) in soybean; however, the results found in cotton were …

Evaluating Soil Health Changes Following Cover Crop And No-Till Integration Into A Soybean (Glycine Max) Cropping System In The Mississippi Alluvial Valley, Alexandra Gwin Firth

Theses and Dissertations

The transition of natural landscapes to intensive agricultural uses has resulted in severe loss of soil organic carbon (SOC), increased CO₂ emissions, river depletion, and groundwater overdraft. Despite negative documented effects of agricultural land use (i.e., soil erosion, nutrient runoff) on critical natural resources (i.e., water, soil), food production must increase to meet the demands of a rising human population. Given the environmental and agricultural productivity concerns of intensely managed soils, it is critical to implement conservation practices that mitigate the negative effects of crop production and enhance environmental integrity. In the Mississippi Alluvial Valley (MAV) region of Mississippi, USA, …

Is Agriculture Being Implemented In Private School Classrooms? The Impact Of Teacher Willingness And Availability Of Resources., Casey Moss

Theses and Dissertations

Agricultural literacy has been a topic of concern as most of the population have little to no understanding of agriculture, and the impact it has on society. Agricultural literacy can be defined as “having knowledge and understanding of agriculturally related scientific and technologically based concepts and processes required for personal decision making” (Meischen & Trexler, 2003, p.44). Numerous studies have been conducted to determine the significance of agricultural literacy beginning with elementary aged children and continuing through high school. The majority of studies conducted focus on public school students and teachers. This has led to a gap in the knowledge …

Evaluating Cover Crops To Determine The Best Management Practice For The Suppression Of Tall Waterhemp And Italian Ryegrass, Samuel R. Reeves

Theses and Dissertations

To combat herbicide resistance among weeds, non-herbicide methods of control, such as cover crops, are becoming widely adapted. Experiments were conducted to determine how to effectively establish and manage cover crops in order to suppress tall waterhemp and Italian ryegrass and to assess their overall impact on soybean growth and yield. Various cover crop establishment methods were evaluated, and it was determined that interseeding at the R7 growth stage of soybean was the least effective method for proper cover crop establishment. Biomass data demonstrated that interseeding created the least amountof cover crop biomass, with no differences found among the other …

Plugging Into A New Age: The Impact Of Social Media Use On Undergraduate Students’ Perceptions Of Production Agriculture And Consumer Decisions, Shannon K. Allen

Theses and Dissertations

Today, 84% of young adults between the ages of 18-29 use at least one social media site (Pew Research Center, 2020) and are in the stages of emerging adulthood where they are making independent decisions for the first time (Arnett, 2000). As society becomes more technologically advanced, we become further removed from agriculture (Powell & Agnew, 2011; Dale et al., 2017). Thus, resulting in a separation between consumer and producer (Wilson & Lusk, 2020; Holt & Cartmell, 2013). This leaves the opportunity for society to turn to social media for agriculture information leading to negative perceptions of agriculture (Eyck, 2000; …

The Guatemala Rabbit Project: A Household Agricultural Intervention Program Evaluation Using The Re-Aim Framework, Jessica Martin Graves

Theses and Dissertations

Amongst the breathtaking and mountainous landscapes of the Western Highlands is a highly indigenous Mayan population stricken with challenges of food insecurity and extreme poverty. Despite efforts by governmental and non-governmental organizations alike to combat these challenges, the results of chronic malnutrition have led to some of the highest child stunting rates in all of Guatemala, particularly in the department of Totonicapán, where this study took place. To date, information is limited regarding agricultural programs that utilize the rabbit as a model to reduce food insecurity in Guatemala. Thus, a novel agricultural education program, Guatemala Rabbit Project (GRP), was developed …

Quantifying The Effects Of Abiotic Stress On Early Season Growth, Development, And Physiological Characteristics In Corn, Charles Hunt Walne

Theses and Dissertations

Corn is one of American agriculture's greatest success stories, where we have witnessed incredible increases in yield potential over the last half-century. However, abiotic stress is still the primary limiting factor preventing plants from reaching their true yield potential. In addition, agriculture is not exempt from the deleterious effects of changing weather patterns and the altered climate our world will face as time progresses. Thus, increasing our understanding of how crops interact with their environment both above and below the soil will be crucial to increasing production on a global scale while maximizing profitability at a local level. Five studies …

Perceptions Of Middle School Students On Gardening, Julie B. White

Theses and Dissertations

The purpose of this study was to describe the perceptions middle school students had about agriculture and gardening as part of the GrOW (Gardening and Overall Wellness) Program. This included multiple constructs, including students’ gardening efficacy, perceptions of those who had already completed the GrOW Program, perceptions of those who had not completed the GrOW Program, and students’ future interests in gardening. The population for this study was sixth-grade students at the Partnership Middle School in Starkville, Mississippi. A quantitative instrument was used to assess the perceptions of the students (n = 222).

Overall, students had positive perceptions about the …