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Electronic Theses and Dissertations

2019

Articles 1 - 16 of 16

Full-Text Articles in Agriculture

The Potential For Dickeya Dianthicola To Be Vectored By Two Common Insect Pests Of Potatoes, Jonas K. Insinga Dec 2019

The Potential For Dickeya Dianthicola To Be Vectored By Two Common Insect Pests Of Potatoes, Jonas K. Insinga

Electronic Theses and Dissertations

Dickeya dianthicola (Samson) causing blackleg and soft rot was first detected in potatoes grown in Maine in 2014. Previous work has suggested that insects, particularly aphids, may be able to vector bacteria in this genus between plants, but no conclusive work has been done to confirm this theory. In order to determine whether insect-mediated transmission is likely to occur in potato fields, two model potato pests common in Maine were used: the Colorado potato beetle (Leptinotarsa decimlineata Say) and the green peach aphids (Myzus persicae Sulzer). Olfactometry and recruitment experiments evaluated if either insect discriminates between infected and …

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Landscape Pattern And Wild Bee Communities In Maine, Brianne Du Clos May 2019

Landscape Pattern And Wild Bee Communities In Maine, Brianne Du Clos

Electronic Theses and Dissertations

Commercial production of lowbush blueberry (Vaccinium angustifolium Aiton) in Maine relies primarily on managed honeybee hives; however, naturally occurring wild bees are more efficient pollinators of the crop. Wild bees have short foraging distances and must nest near crop fields to provide pollination services. After crop bloom, the surrounding landscape must provide sufficient forage to maintain wild bee populations for the remainder of the growing season. Lowbush blueberries in Maine are produced in a mixed-use landscape with two distinct landscape contexts. Here, we document bee communities and habitat resources (nesting and floral) in power line rights-of-way and eight land …

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Eyes In The Field, A Seat At The Table, A Voice At The Ranch : A Study On Optimal Farm Labor Conditions., Christine Wiggins-Romesburg May 2019

Eyes In The Field, A Seat At The Table, A Voice At The Ranch : A Study On Optimal Farm Labor Conditions., Christine Wiggins-Romesburg

Electronic Theses and Dissertations

The field of human resource development has twin obligations to promote the performance of organizations and the satisfaction and welfare of all workers. Nevertheless, agriculture appears to be an understudied industry in the field, despite this obligation and the potential for suffering experienced by workers performing crop work. This case study sought to understand the process through which a single agricultural operation fosters optimal conditions for workers engaged in labor-intensive crop production. This study found employees experienced better treatment compared to other agricultural operations, and that conditions were rich in both intrinsic and extrinsic factors. Intrinsic factors were marked by …

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Development Of Enhanced Weed Detection System With Adaptive Thresholding, K-Means And Support Vector Machine, Dheeman Saha Jan 2019

Development Of Enhanced Weed Detection System With Adaptive Thresholding, K-Means And Support Vector Machine, Dheeman Saha

Electronic Theses and Dissertations

This paper proposes a sophisticated classification process to segment the leaves of carrots from weeds (mostly Chamomile). In the early stages, of the plants’ development, both weeds and carrot leaves are intermixed with each other and have similar color texture. This makes it difficult to identify without the help of the domain experts. Therefore, it is essential to remove the weed regions so that the carrot plants can grow without any interruptions. The process of identifying the weeds become more challenging when both plant and weed regions overlap (inter-leaves). The proposed system addresses this problem by creating a sophisticated means …

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Preservice Agricultural Education Majors’ Perceptions Of Integrating Science Into Agriculture, Kasey Trocke Jan 2019

Preservice Agricultural Education Majors’ Perceptions Of Integrating Science Into Agriculture, Kasey Trocke

Electronic Theses and Dissertations

Agricultural science has seen a rise in secondary agricultural classrooms and many studies have been done with regards to integrating science into agriculture. Several recommendations have been to assist preservice agriculture education majors with science integration. Preservice agricultural education majors could influence the future of agricultural science due to their perceptions of integrating science into agriculture into the classroom. The purpose of the study was to assess preservice teachers’ perceptions of integrating science into agriculture curriculum based on the theory of planned behavior. An online survey was administered to the population of agricultural education majors at South Dakota State University. …

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Augmenting Land Cover/Land Use Classification By Incorporating Information From Land Surface Phenology: An Application To Quantify Recent Cropland Expansion In South Dakota, Lan Hoang Nguyen Jan 2019

Augmenting Land Cover/Land Use Classification By Incorporating Information From Land Surface Phenology: An Application To Quantify Recent Cropland Expansion In South Dakota, Lan Hoang Nguyen

Electronic Theses and Dissertations

Understanding rapid land change in the U.S. NGP region is not only critical for management and conservation of prairie habitats and ecosystem services, but also for projecting production of crops and biofuels and the impacts of land conversion on water quality and rural transportation infrastructure. Hence, it raises the need for an LCLU dataset with good spatiotemporal coverage as well as consistent accuracy through time to enable change analysis. This dissertation aims (1) to develop a novel classification method, which utilizes time series images from comparable sensors, from the perspective of land surface phenology, and (2) to apply the land …

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Interactions Of Arbuscular Mychorrhizal Fungi And Bacterial Endophytes On Disease Resistance Of Common Root Pathogens In Wheat, Janice L. Eibensteiner Jan 2019

Interactions Of Arbuscular Mychorrhizal Fungi And Bacterial Endophytes On Disease Resistance Of Common Root Pathogens In Wheat, Janice L. Eibensteiner

Electronic Theses and Dissertations

Arbuscular mycorrhiza, a symbiosis between plants and fungi, help plants to capture nutrients such as phosphorus (P), nitrogen (N) and other micronutrients from the aggre in exchange for up to 20% of the fixed carbon (C) from the plant. In addition, arbuscular mycorrhizal (AM) fungi can improve the resistance against abiotic (drought, salinity), and also biotic (pathogen) stresses. Bacterial endophytes promote plant growth and yield by fixing N2 from the atmosphere, assimilating N and transfer it to the plant. Bacterial endophytes can also solubilize phosphate and stimulate plant defense responses, suppressing pathogens. The host plant provides sucrose and a favorable …

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Identification And Characterization Of Stress Responsive Genes In Soybean And Sunflower, Surendra Neupane Jan 2019

Identification And Characterization Of Stress Responsive Genes In Soybean And Sunflower, Surendra Neupane

Electronic Theses and Dissertations

Stress responsive genes encode proteins involved in plants’ response to abiotic and biotic stresses. Among such stress responsive proteins, proteins encoded by resistance genes (R genes) or nucleotide binding site-leucine-rich repeats (NBS-LRRs) and mitogen-activated protein kinases (MAPKs) are the major groups of proteins regulating biotic and abiotic stresses, respectively. Previous studies in Nepal’s lab at SDSU identified and characterized coiled coil (CC)-NBS-LRRs (CNLs), resistance to powdery mildew8 (RPW8)-NBS-LRRs (RNLs), NBS-LRR (NLs), and MAPK proteins in soybean. This study focuses on R and MAPK genes in the recently sequenced genome of sunflower as well as the toll-interleukin-1 receptor-like nucleotide-binding site leucine-rich …

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Perceptions Of Wyoming Agriculture Teachers About The Importance Of Sae’S, Casey Styvar Jan 2019

Perceptions Of Wyoming Agriculture Teachers About The Importance Of Sae’S, Casey Styvar

Electronic Theses and Dissertations

Agricultural education in the United States after the Smith Hughes Act has always included a component of the home-based project method, which now is known as a supervised agricultural experience program (SAEP). This method of instruction teaches and provides students with a hands-on learning experience inside and outside of the classroom. The benefits that students receive with this form of the curriculum are second to none. Agriculture educators realize the benefits of SAE programs and how their students expand and grow in their education and skills from having an SAE. Due to changes in student and teacher culture, it is …

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Sunflower Pollinators In South Dakota: An Evaluation Of Species Composition, Abundance And Influence On Yield, Mackenzie Mattern Jan 2019

Sunflower Pollinators In South Dakota: An Evaluation Of Species Composition, Abundance And Influence On Yield, Mackenzie Mattern

Electronic Theses and Dissertations

In 2017 and 2018, South Dakota was the largest producer of sunflowers, Helianthus annuus L. (Asterales: Asteraceae) in the US, grossing approximately $178 million per year. In South Dakota, both confection and oilseed sunflower cultivars are grown. Despite breeding efforts to increase sunflower's ability to self-pollinate there is evidence that pollinator visitation results in increased sunflower yields. In addition, there is evidence that sunflower pollen is beneficial for pathogen resistance in various bee species, suggesting the importance of a mutualistic relationship between pollinators and sunflowers. In some areas, observed increases in sunflower yield is attributed to the presence of Apis …

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Agronomic And Quality Response Of Hard Red Spring Wheat Genotypes To Management Systems In South Dakota, Jonathan Kleinjan Jan 2019

Agronomic And Quality Response Of Hard Red Spring Wheat Genotypes To Management Systems In South Dakota, Jonathan Kleinjan

Electronic Theses and Dissertations

Intensive cereals management techniques such as multiple fungicide applications and in-season split N applications have been used to successfully improve wheat yields in Europe and in some winter wheat production areas of the USA. However, research on the effects of these management practices and their interaction with genotypes is limited in the hard red spring wheat (HRSW) production areas of the USA. The objectives of this study were to: (i) compare management treatments and (ii) quantify any interaction effects between management and genotype on the agronomic characteristics and relevant flour and dough properties of locally-adapted HRSW genotypes. A randomized complete …

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Maximizing Ecosystem Services Provided To The New Oil Crop Brassica Carinata Through Landscape And Arthropod Diversity, Shane Stiles Jan 2019

Maximizing Ecosystem Services Provided To The New Oil Crop Brassica Carinata Through Landscape And Arthropod Diversity, Shane Stiles

Electronic Theses and Dissertations

Prairies, once spanning the Upper Midwest, have now largely been replaced by agriculture. The lack of resources available to pollinators in agricultural fields and the practices employed by farmers to maximize yield has led to a decline in insect and pollinator diversity. There is a need to better understand how ecosystem services provided by a diverse insect community scale to current farming practices as they relate to crop yield. We sought to explain how landscape heterogeneity relates to insect and pollinator diversity, as well as how insect diversity relates to crop yield across common farming practices. To evaluate how farming …

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Parents In Urbanized Areas And Their Perception Of 4-H Youth Development Programs, Matthew Ryan Olson Jan 2019

Parents In Urbanized Areas And Their Perception Of 4-H Youth Development Programs, Matthew Ryan Olson

Electronic Theses and Dissertations

This study examined the perceptions held by parents living in the urbanized area of Rapid City, South Dakota, to determine if artificial barriers to joining 4-H PYD programs existed. Through snowball sampling methods, nine participants were recruited to engage in semi-structured interviews. Transcripts from the interviews were coded utilizing in vivo and axial coding methods. Four themes emerged from the interviews: characteristics of youth development programs, program promotion through school flyers, barriers to joining youth development programs, and 4-H and its connection to agriculture. The major recommendation for 4-H professionals is to focus on leadership, life skills, and character development …

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Undoing Gender: An Analysis Of How Women Communicate Within The Agricultural Industry, Shala R. Larson Jan 2019

Undoing Gender: An Analysis Of How Women Communicate Within The Agricultural Industry, Shala R. Larson

Electronic Theses and Dissertations

In recent history, women have entered more business-like positions in the agricultural industry. This thesis seeks to understand how women in agriculture describe their workplace communication and whether they feel they are part of a muted group. Twelve women were interviewed regarding their experiences as women in agriculture and were asked whether they feel valued in their positions and how they communicate with their male co-workers. Specifically, interviewees were asked if they ever felt the need to alter their communication to complement, emulate, or otherwise adjust to masculine communication styles. The majority of women interviewed reported having to strategically choose …

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Diversifying Cornfields By Interseeding Cover Crops: Practical Implications And The Response Of Invertebrate Communities, Michael Bredeson Jan 2019

Diversifying Cornfields By Interseeding Cover Crops: Practical Implications And The Response Of Invertebrate Communities, Michael Bredeson

Electronic Theses and Dissertations

The lack of suitable habitat conditions for beneficial organisms in simplified agroecosystems leads to unstable invertebrate communities and overreliance on chemical control of herbivores. It is possible to manage pest populations without agrichemicals by manipulating farmland so that herbivores are impaired by plant-driven bottom-up and enemy-driven top-down antagonisms. Interseeding cover crops between established crop rows is a method used by farmers to improve habitat suitability for natural enemies and hinder host-finding, feeding and movement by herbivores. Here I address three important research gaps related to interseeding cover crops. A calcium carbonate seed coating, used to improve seed-broadcasting efficiency, was tested …

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Hydrodynamic Cavitation As In-Line Process To Control Common Dairy Sporeformers, Pratibha Chaudhary Jan 2019

Hydrodynamic Cavitation As In-Line Process To Control Common Dairy Sporeformers, Pratibha Chaudhary

Electronic Theses and Dissertations

Sporeforming bacteria and their endospores have the ability to survive thermal treatments and proliferate in the milk and dairy products to cause spoilages. We applied the effect of hydrodynamic cavitation in controlling these bacteria and their spores at pilot scale level. Our aim was to investigate a technology that would improve the microbial quality of milk and dairy products, and is capable of being scaled up to be adapted at industrial level. Cavitation damages the cell walls of the bacteria and their endospores (releasing dipicolinic acid, responsible for endospore resistance to extreme conditions), thereby making them susceptible to thermal treatments …

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