Agriculture Commons^™

Oystershell Scale: An Invasive Threat To Aspen Conservation, Amanda M. Grady, Connor D. Crouch, Nicholas P. Wilhelmi, Richard W. Hofstetter, Kristen M. Waring

Aspen Bibliography

Aspen decline is an acute and chronic problem in Arizona, where high levels of overstory mortality and a lack of recruitment continue to be observed. Oystershell scale (Lepidosaphes ulmi; OSS), an invasive sapsucking insect, has recently become widespread in native aspen stands in the southwestern U.S., further contributing to aspen mortality. Damage is severe in lower elevation stands and within ungulate exclosures created to conserve aspen. Young recruiting aspen that are rare on the landscape incur high levels of OSS-caused mortality when infested (Fig. 1). OSS has only recently become a pest of concern in the Southwest and …

Economic Viability Of Weed Management Strategies In High-Tunnel Tomato, Gracie Morrison

Crop, Soil and Environmental Sciences Undergraduate Honors Theses

Cost-effective weed suppression is an important consideration for tomato growers. Growers often choose methods which minimize hand labor, as hand weeding can be prohibitively expensive. This project determined economic viability of high tunnel tomatoes treated with several methods of weed control, both organic and chemical. These methods included: 2-week hand weeding, 1-week hand weeding, preemergent, straw, landscape fabric, and untreated weedy control plots. These treatments were applied to randomized blocks in a high-tunnel. Weeding, planting, and harvest were all timed to determine labor and material costs of weed management strategy implementation. After harvest, marketable yield was weighed to determine revenue. …

Consumer Preferences For Lab Grown Meat: The Effect Of Information On Consumer Choice, Aryn Blumenberg

Food Science Undergraduate Honors Theses

Global population growth and increased meat demand present challenges for the agricultural industry to produce meat sustainably. In-vitro meat (IVM) is an alternative that could reduce negative impacts associated with livestock production. The goal of this study was to examine consumers’ preferences for IVM. A choice experiment was created with twelve choice tasks that varied across five attributes: production method (IVM or conventional), carbon trust label, organic label, animal welfare label, and price. 1,120 US consumers were randomly assigned to one of four information treatments, differing by information presented regarding IVM: 1) neutral (baseline), 2) positive, 3) negative, and 4) …

Pasture Biomass Estimation Using Crop Surface Modeling And Vegetation Indices, Brendan Macinnis

All Theses

Biomass estimations are a critical function of any grazing or haylage system. Determination of ideal harvesting or grazing times help optimize the quality and quantity of above-ground biomass (AGB). The objective of this study was to evaluate the use of unmanned aerial vehicles (UAVs) for Alfalfa and Tall Fescue biomass estimations. Using a DJI Mavic Pro, RGB and NDVI images were taken and used to create orthomosaic images. Structure-from-motion (SfM) techniques were used to developed digital elevation models to evaluate the change in canopy height (∆H) between pre- and post-harvests. Change in canopy height (∆H) was shown to provide the …

Unraveling The Genetic Architecture Of Somatic Embryogenesis In Upland Cotton, Adam M. Canal

All Theses

Somatic embryogenesis is the de novo development of asexual embryos because of the plasticity of the plant cell. In tissue culture, the biochemical and genetic mechanisms of dedifferentiated callus tissues can be reprogrammed to transdifferentiate into developed, polarized embryos, which can ultimately regenerate into whole plants. Although this rarely occurs in nature, scientists have exploited this process for decades to regenerate whole plants following gene transformation or for micropropagation. While some species are amenable to in vitro regeneration, upland cotton is particularly recalcitrant, with regenerative potential being confined to only several genotypes. The lack of elite, regenerable genotypes greatly restricts …

First Line Of Defense: Role Of Surface Waxes In Sorghum Defense Against Aphids, Juan David Betancurt Cardona

Department of Entomology: Dissertations, Theses, and Student Research

Since 2013, the sugarcane aphid (SCA; Melanaphis sacchari) has become a devastating pest in sorghum (Sorghum bicolor) in the United States. Efforts to mitigate this pest and contain its rapid population growth have increased recently. Host plant resistance (HPR) is an effective and environmentally friendly strategy to reduce aphid populations in this crop. Many factors make SCA a challenging pest to control. For example, SCA can overcome drastic climatic changes, which allows them to successfully colonize sorghum plants at different developmental stages.

Epicuticular waxes (EW) constitute the first point of contact between plants and their environment. EW …

Interactions Between Resistance Genes In Wheat Triticum Aestivum L. And Wheat Curl Mite Populations Aceria Tosichella Keifer (Eriophyidae), Tran Kim Ngan Luong

Department of Entomology: Dissertations, Theses, and Student Research

Wheat curl mite (WCM) (Aceria tosichella Keifer) is a major pest of winter wheat (Triticum aestivum L.), being the only known vector of three damaging plant viruses, Wheat streak mosaic virus, Triticum mosaic virus, and High Plains wheat mosaic virus. This wheat-mite-virus complex causes significant yield loss globally. Management has been mostly through cultural practices to reduce mite build up in volunteer wheat, thereby reducing the spread of viruses. Host plant resistance to WCM has also been used as an important management strategy for this wheat-mite-virus complex. However, WCM is a cryptic species complex, resulting …

Teaching Programmable Microcontrollers To Novice Users In A College Of Agriculture: Effects On Attitude, Self-Efficacy, And Knowledge, Grant T. Hood

Graduate Theses and Dissertations

This thesis consists of two articles that examined an instructional treatment based on the use of Arduino UNO R3 programmable microcontrollers in a fundamentals of agriculture systems technology course at the University of Arkansas. The first article examined students’ breadboarding and programming self-efficacy and knowledge of Arduino. The treatment consisted of a three-class-period instructional treatment, starting with a pretest before instruction to measure students’ baseline interest, knowledge, and self-efficacy of breadboarding and programming Arduino. This was followed with a short 30-minute instructional video explaining basic Arduino programming and breadboarding. Next a hands-on laboratory activity requiring students to breadboard and program …

Exploration Of Genes Controlling Grain Yield Heterosis In Hybrid Wheat (Triticum Aestivum L.) Utilizing 3ʹ Rna Sequencing, Nichole Lynn Miller

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

The implementation and future success of hybrid wheat (Triticum aestivum L.) is impacted by breeders’ inability to create consistent high yielding, high heterosis hybrids. This research addresses this problem by conducting an exploration of transcriptomes from hybrids and parent lines to determine what genes are active in heterotic or non-heterotic hybrids and how their level of expression can explain the phenotype of grain yield heterosis. Using hybrids that showed positive mid-parent heterosis (MPH), classified as heterotic in our study, and negative or no difference MPH hybrids, classified as non-heterotic, differentially expressed genes (DEGs) potentially related to heterosis and hybrid …

Chromosome-Level Thlaspi Arvense Genome Provides New Tools For Translational Research And For A Newly Domesticated Cash Cover Crop Of The Cooler Climates, Adam Nunn, Isaac Rodríguez-Arévalo, Zenith Tandukar, Katherine Anna Frels, Adrián Contreras-Garrido, Pablo Carbonell-Bejerano, Panpan Zhang, Daniela Ramos Cruz, Katharina Jandrasits, Christa Lanz, Anthony Brusa, Marie Mirouze, Kevin Dorn, David W. Galbraith, Brice A. Jarvis, John C. Sedbrook, Donald L. Wyse, Christian Otto, David Langenberger, Peter F. Stadler, Detlef Weigel, M. David Marks, James A. Anderson, Claude Becker, Ratan Chopra

Department of Agronomy and Horticulture: Faculty Publications

Thlaspi arvense (field pennycress) is being domesticated as a winter annual oilseed crop capable of improving ecosystems and intensifying agricultural productivity without increasing land use. It is a selfing diploid with a short life cycle and is amenable to genetic manipulations, making it an accessible field-based model species for genetics and epigenetics. The availability of a high-quality reference genome is vital for understanding pennycress physiology and for clarifying its evolutionary history within the Brassicaceae. Here, we present a chromosome-level genome assembly of var. MN106-Ref with improved gene annotation and use it to investigate gene structure differences between two accessions (MN108 …

Pestfacts Wa Issue 03 - May 2022, Svetlana Micic, Dustin Severtson, Jean Galloway, Cindy L. Webster

PestFacts WA

PestFacts WA Issue 03 - May 2022 contents:

• Seeing chewing damage in sprayed canola crops but can’t find the culprit?
• Mites and lucerne flea are active
• Slaters
• Meet PestFacts WA team member – Svetlana Micic
• Field pea blackspot forecasts for WA are available online
• PestFacts WA podcast

The Work Of La Via Campesina Regarding The Intersection Of Land Occupation And Food Sovereignty, Josephine Drydale

International and Global Studies Undergraduate Honors Theses

La Via Campesina (LVC), a global movement that supports small and local farmers and their communities, is one of the world’s largest food and agricultural rights movements and advocates for agricultural rights in terms of land, ecology, human rights, and more. LVC is known for its establishment of food sovereignty, defined as the right to control one’s production and consumption of food. This new concept placed them on the map, accompanied by their aggressive editorial and advocacy work against ideals they view as neoliberal and food policies that benefit large food moguls while disenfranchising the small farmer. The concept of …

The Last Leg: A Social Sustainability Assessment Of Ovine Agriculture, Sydney Golding

International and Global Studies Undergraduate Honors Theses

Post-war agricultural transformations and the rise of Sustainability discourses have dictated the trajectory of sector industries. The implications of agriculture in lateral policy schemes have neglected the careful consideration of the social health of farmers in decision-making processes, creating a greater divide between the interests of the state and our once revered providers. This study aims to capture the complexity of social matters in agriculture within the specific context of sheep farming in the United Kingdom and the United States and how the concurrent systems have adapted considering the impacts of relevant contemporary historical contexts. The principles of Janker, Mann, …

Bumpers College Of Agricultural, Food And Life Sciences Professional Development Opportunities And Their Impact On Perceptions Of Career Preparedness, Jessica L. Wesson

Graduate Theses and Dissertations

A student’s undergraduate education is an imperative part of developing career skills that will prepare them to transition from academia to the professional world. Experience outside of the classroom and course material taught in a formal class experience are both important. Their experiences and classes, in college, allow them to develop skills and increase their chances of being successful in the workplace (Suvedi et al., 2016).

Chickering’s Seven Vectors of Student Development were used to help explain the process of student development. A quantitative survey was sent to DBCALFS faculty, staff, and administrators, and a different quantitative survey was sent …

Wayne E. Sabbe Arkansas Soil Fertility Studies 2021, Nathan A. Slaton

Arkansas Agricultural Experiment Station Research Series

Rapid technological changes in crop management and production require that the research efforts be presented in an expeditious manner. The contributions of soil fertility and fertilizers are major production factors in all Arkansas crops. The studies described within will allow producers to compare their practices with the university’s research efforts. Additionally, soil-test data and fertilizer sales are presented to allow comparisons among years, crops, and other areas within Arkansas.

Oestrogenic Subterranean Clover Guide. Identification And Remediation, Kevin J. Foster, Megan H. Ryan, Daniel R. Kidd

Bulletins 4000 -

Subterranean clover (subclover, Trifolium subterraneum L.) is an annual pasture legume that provides high quality feed for livestock. It is estimated to be sown over 30 million hectares across southern Australia, with cultivars developed for the low, medium and high rainfall zones. Unfortunately, some older cultivars contain high levels of phytoestrogen which can affect the reproductive system of sheep and cause other health issues. This became a significant issue for sheep producers from the 1940s as new land was cleared and sheep grazed subclover-dominant pastures. There was a collection of livestock issues observed and these were grouped together under the …

Linking Soil Microbial Community Structure To Potential Carbon Mineralization: A Continental Scale Assessment Of Reduced Tillage, Elizabeth L. Rieke, Shannon B. Cappellazzi, Michael Cope, Daniel Liptzin, G. Mac Bean, Kelsey L.H. Greub, Charlotte E. Norris, Paul W. Tracy, Ezra Aberle, Amanda Ashworth, Oscar Bañuelos Tavarez, Andy I. Bary, R. L. Baumhardt, Alberto Borbón Gracia, Daniel C. Brainard, Jameson R. Brennan, Dolores Briones Reyes, Darren Bruhjell, Cameron N. Carlyle, James J.W. Crawford, Cody F. Creech, Steve W. Culman, Bill Deen, Curtis J. Dell, Justin D. Derner, Thomas F. Ducey, Sjoerd W. Duiker, Miles F. Dyck, Benjamin H. Ellert, Avelino Espinosa Solorio, Steven J. Fonte, Simon Fonteyne, Ann Marie Fortuna, Jamie L. Foster, Lisa M. Fultz, Audrey V. Gamble, Charles M. Geddes, Deirdre Griffin-Lahue, John H. Grove, Stephen K. Hamilton

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Potential carbon mineralization (Cmin) is a commonly used indicator of soil health, with greater Cmin values interpreted as healthier soil. While Cmin values are typically greater in agricultural soils managed with minimal physical disturbance, the mechanisms driving the increases remain poorly understood. This study assessed bacterial and archaeal community structure and potential microbial drivers of Cmin in soils maintained under various degrees of physical disturbance. Potential carbon mineralization, 16S rRNA sequences, and soil characterization data were collected as part of the North American Project to Evaluate Soil Health Measurements (NAPESHM). Results showed that type of cropping system, intensity of physical …

Winners And Losers In Dryland Reforestation: Species Survival, Growth, And Recruitment Along A 33-Year Planting Chronosequence, Clifton Albrecht, Zarek Contreras, Kimberly Wahl-Villarreal, Mitch Sternberg, Bradley O. Christoffersen

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

Reforestation in the Lower Rio Grande Valley (LRGV) of Texas began in the 1960s and to date over 6,475 ha of land has been reforested. However, there has been minimal assessment to understand differential species success, compositional trends, and the aboveground C sequestration potential of these developing forests. We coupled quantitative planting information of >50 native woody tree and shrub species with surveys of 5,223 stems of 4,606 individuals in a chronosequence of restored forests ranging in age from 1 to 33 years to estimate species-specific mortality rates, biomass accumulation and recruitment, as well as compositional trends in the herbaceous …

Teaching For Career Success: An Agricultural Industry Perspective Of Preparedness Needs For Diverse Workforce Development, Madelaine Giebler

Graduate Theses and Dissertations

This research examined agricultural graduate preparedness needs through the lens of agricultural industry professionals. In the rapidly changing industry environment, continual review of agricultural curriculum needs provides relevant curriculum recommendations for academic programs. This study came at a time when agricultural curriculum was in need of review. Methodology for this study involved a qualitative mixed methods approach employing survey and interview responses. A total of 121 industry professionals, identified through the University of Arkansas Bumpers College Career Development Center, were contacted with the survey link. A total of eighteen individuals completed the surveys, and of those eighteen survey respondents, eight …

Targeting Inflammation In Heat-Stressed Wethers Improves Growth And Efficiency And Alters Body Composition: A Brief Exploration And Application Of Extension Principles, Micah Samuel Most

Department of Animal Science: Dissertations, Theses, and Student Research

The objective of our first study was to determine how administering anti-inflammatory dexamethasone and ω-3 polyunsaturated fatty acid (PUFA)-rich fish oil affects growth efficiency and body composition in heat-stressed finishing lambs. Commercial wethers were randomly assigned to be fed under heat stress (35-40 ℃) or thermoneutral (19 ℃, n = 10) conditions for 30 d, and controls were pair-fed to eliminate differential feed intake. Heat-stressed wethers were randomly assigned to receive clinical-dose dexamethasone IM injections every 72 h, twice daily fish oil capsule oral boluses, or placebos. Heat stress decreased (P < 0.05) growth and efficiency, but dexamethasone and fish oil supplementation recovered these performance measures. Heat stress also decreased (P < 0.05) predictive body composition metrics that were at least partially improved by administration of dexamethasone and fish oil. Proximate analyses of muscles showed that heat stress decreased (P < 0.05) percentage of protein and increased (P < 0.05) percentage of intramuscular fat, neither of which was improved by dexamethasone or fish oil. Immunohistochemistry revealed that heat stress decreased (P < 0.05) myoblast differentiation and muscle fiber size, but anti-inflammatory supplementation recovered differentiation only. Plasma IGF-1 concentrations were not different among groups throughout the study. These findings demonstrate how heat stress-induced inflammation contributes to impaired growth, efficiency, and body composition observed in heat-stressed feeder lambs. However, targeting inflammation with dexamethasone or fish oil recovers many of these deficits.

The Cooperative …