Open Access. Powered by Scholars. Published by Universities.®

Agronomy and Crop Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 30 of 289

Full-Text Articles in Agronomy and Crop Sciences

Establishment Of Native Warm-Season Forages Using Organic Practices, Kolten Ray Wright Dec 2025

Establishment Of Native Warm-Season Forages Using Organic Practices, Kolten Ray Wright

Graduate Theses and Dissertations

Abstract Grassland agriculture is seen as a particularly sustainable form of agriculture. Many opportunities are known to use organic production methods or incorporate native warm-season grasses (NWSG) to accomplish both production goals and environmental or social outcomes. Environmental concerns have led some practitioners to question the use of organic methods to establish NWSG. As limited work has been accomplished in the northern bermudagrass belt, this project sought to compare organic establishment strategies for common NWSG species. A field trial conducted at the USDA ARS Dale Bumpers Small Farms Research Center in Booneville, AR found that NWSG establishment success in the …


Understanding Glufosinate Resistance In Palmer Amaranth And Examination Of Additives For Improved Weed Control, Pamela Carvalho-Moore Sep 2025

Understanding Glufosinate Resistance In Palmer Amaranth And Examination Of Additives For Improved Weed Control, Pamela Carvalho-Moore

Graduate Theses and Dissertations

The aim of this dissertation was to: 1) provide an in-depth review about the potential use of natural and synthetic glutathione S-transferase (GST) inhibitors to enhance herbicidal activity or induce crop safety; 2) determine if the addition of metabolic inhibitors to glufosinate is an effective approach to enhance weed control; 3) investigate the mechanism conferring resistance to glufosinate in a highly-resistant Palmer amaranth accession; 4) characterize the genomic rearrangement involved in glutamine synthetase 2 amplification in a Palmer amaranth accession resistant to both glufosinate and glyphosate; 5) quantify the distribution of glufosinate resistance among Palmer amaranth accessions within a 15-km …


Modeling U.S. Corn Production Archetypes In The Agricultural Policy/Environmental Extender Model To Generate Life Cycle Assessment Inventory Data, Brandon Taylor Aug 2025

Modeling U.S. Corn Production Archetypes In The Agricultural Policy/Environmental Extender Model To Generate Life Cycle Assessment Inventory Data, Brandon Taylor

Graduate Theses and Dissertations

Corn (Zea mays) is an important crop grown across the US for many uses such as grain for animal feed, bio-ethanol production, food products, and industrial products. Corn is produced in almost every state in the US, but most corn production is concentrated in the Corn Belt Region including Iowa, Illinois, Ohio, Indiana, Minnesota, and Nebraska. Although technologies and production practices are improving corn production efficiency primarily through increased yields (improved land use), corn production at this scale greatly impacts the environment through emissions from fertilizer and pesticide runoff and leaching, soil degradation due to improper field practices, as well …


Heterogeneous Yield Effects Of Cover Crop Adoption In U.S. Corn And Soybean Systems, Ethan Kendall Aug 2025

Heterogeneous Yield Effects Of Cover Crop Adoption In U.S. Corn And Soybean Systems, Ethan Kendall

Graduate Theses and Dissertations

Identifying the conditions where cover crops will succeed or fail is crucial for advancing conservation agriculture. Cover crops have been widely accepted as a conservation practice that can improve soil health and might improve or stabilize crop yields, though these benefits are not consistent across different regions. This study examines how heterogeneous factors can shape the effectiveness of cover crops on corn and soybean yields across the United States. Using the National Commodity Crop Productivity Index (Index) to measure soil productivity, this study examines how cover crop impacts vary across different levels of soil quality. A county level, 16- year …


Enhancing Selection Intensity With High-Throughput Phenotyping Data In Plant Breeding, Ashmita Upadhyay Dec 2024

Enhancing Selection Intensity With High-Throughput Phenotyping Data In Plant Breeding, Ashmita Upadhyay

Graduate Theses and Dissertations

Genomic prediction (GP) has proven to be an essential tool to accelerate the cultivar development pipeline by predicting the performance of un-phenotyped lines in the field of plant breeding. However, the prediction accuracy is bounded by the heritability of the target trait, limiting the efficiency of the single-trait GP model. To overcome the limitation, a multi-trait genomic prediction model using high-throughput phenotyping (HTP) data can be used to leverage secondary traits to boost the predictive ability of the target trait. This study aimed to assess the efficiency of the multi-trait (MT)- GP model powered by HTP derived secondary traits in …


Detection Of Fungicide Resistance In Population Of Corynespora Cassiicola From Arkansas Soybean And Cotton Fields, Rafael Zaia Aug 2024

Detection Of Fungicide Resistance In Population Of Corynespora Cassiicola From Arkansas Soybean And Cotton Fields, Rafael Zaia

Graduate Theses and Dissertations

Target spot, caused by the fungus Corynespora cassiicola, has reemerged since 2016 as an economically important disease on soybean and cotton across the Southern U.S. The quinone outside inhibitors (QoI) and succinate dehydrogenase inhibitors (SDHI) are important fungicide classes used to control foliar diseases in soybean and cotton. The efficacy of these products is rapidly decreasing, impacting control, and causing significant yield losses. The overall objective of this study was to determine the risks associated with chemical control by screening fungicide sensitivity, evaluating target site alterations, and analysis of disease control efficacy and yield response of fungicides for soybean in …


Assessment Of The Drivers Of Adoption Of Climate Smart Agriculture Practices Among Field Crop Farmers In Zambia, Faindani Nyirenda Aug 2024

Assessment Of The Drivers Of Adoption Of Climate Smart Agriculture Practices Among Field Crop Farmers In Zambia, Faindani Nyirenda

Graduate Theses and Dissertations

Climate smart agriculture (CSA) practiced has been promoted in Zambia since the 1980s to address the declining crop productivity due to increased occurrence of drought or dry spells caused by climate change. Despite considerable research indicating that CSA practices have many potential benefits such as increased yield and income, the adoption rate in southern Africa is still low especially where farmers have stable off farm income. This might be because most of the research and promotion has been directed to the main staple crop maize and other context specific impacts related to agroecological and socioeconomic heterogeneity. In this study we …


The Effects Of Cover Crop Adoption On Yield Distributions Under Extreme Drought, Emory Johnson Aug 2024

The Effects Of Cover Crop Adoption On Yield Distributions Under Extreme Drought, Emory Johnson

Graduate Theses and Dissertations

Increased frequency and severity of extreme weather events due to climate change negatively impact agriculture output. Of particular concern is the adverse impact of droughts on corn and soybean yields, as these crops represent a significant portion of cash crop receipts in the United States. Cover crops are one practice that has gained attention due to their agronomic benefits and their potential to reduce downside production risk for producers. This study focuses on the impact of cover crop adoption on corn and soybean yields during drought conditions. We use cover crop adoption data from the Operational Tillage Information System, RMA …


Use Of Herbicides Coated Onto Fertilizer And Applied Over-The-Top Of Cotton, Summer Linn Aug 2024

Use Of Herbicides Coated Onto Fertilizer And Applied Over-The-Top Of Cotton, Summer Linn

Graduate Theses and Dissertations

Cotton (Gossypium hirsutum L.) production faces numerous challenges, many related to weed management. A herbicide application method that focuses on combing resources that producers already have access to, such as herbicide-coated fertilizers, could be a practical approach for addressing late-season control of Palmer amaranth (Amaranthus palmeri S. Wats) and other problematic weed species. Two main factors would potentially impact the efficiency of utilizing this method: cotton tolerance to the application and weed control provided by the herbicide-coated fertilizers. Some considerations could affect the efficacy of these applications, such as when the treatments are applied and when they are activated by …


Evaluation Of A Diflufenican:Metribuzin:Flufenacet Premixture For Soybean Tolerance And Weed Control, Matthew Coleman Woolard Aug 2024

Evaluation Of A Diflufenican:Metribuzin:Flufenacet Premixture For Soybean Tolerance And Weed Control, Matthew Coleman Woolard

Graduate Theses and Dissertations

Palmer amaranth [Amaranthus palmeri (S.) Wats.] and waterhemp [Amaranthus tuberculatus (Moq.) Sauer] ranks among the most troublesome weeds of soybean [Glycine max (L.) Merr.], having evolved resistance to multiple herbicide sites of action. Bayer CropScience has announced its intentions to launch Convintro™ brand herbicides, one being a three-way premixture for use preplant until 3 d after planting in soybean. The premixture will include diflufenican (WSSA Group 12), metribuzin (WSSA Group 5), and flufenacet (WSSA Group 15) (DFF-containing premixture), adding a new site of action for use in soybean throughout the United States. In 2022 and 2023, field trials were conducted …


Approaches To Controlling Palmer Amaranth And Its Interference In Furrow-Irrigated Rice, Tanner Austin King Aug 2024

Approaches To Controlling Palmer Amaranth And Its Interference In Furrow-Irrigated Rice, Tanner Austin King

Graduate Theses and Dissertations

Palmer amaranth (Amaranthus palmeri S. Wats) is the most troublesome and problematic weed in most mid-southern U.S. row crop production systems. With the increased adoption of furrow-irrigated rice (Oryza sativa L.), there is a greater occurrence of Palmer amaranth due to sustained moist conditions allowing continual emergence of the weed throughout the growing season. Palmer amaranth has previously been shown to negatively affect crop yields when left unmanaged. Therefore, there is a high potential for rice yield loss due to the weed’s ability to emerge over an extended period and interfere with crop development. However, there is a lack of …


Evaluation Of A Capsule Suspension Formulation Of S-Metolachlor For Use In Fenclorim-Treated Rice And Wheat, Samuel Charles Noe Aug 2024

Evaluation Of A Capsule Suspension Formulation Of S-Metolachlor For Use In Fenclorim-Treated Rice And Wheat, Samuel Charles Noe

Graduate Theses and Dissertations

The continued evolution of herbicide resistance is one of the primary concerns facing Arkansas growers today. Problematic weeds such as barnyardgrass [Echinochloa crus-galli (L.) Beauv.] and Italian ryegrass [Lolium perenne L. ssp. multiflorum (Lam.) Husnot] have evolved resistance to some of the most used herbicides in rice (Oryza sativa L.) and wheat (Triticum aestivum L.). To counteract this resistance, alternative herbicide sites of action should be explored. S-metolachlor is a very-long-chain fatty acid (VLCFA)-inhibiting herbicide [Herbicide Resistance Action Committee (HRAC)/Weed Science Society of America (WSSA) Group 15] commonly used in U.S. row crops to control grasses and small-seeded broadleaf weeds. …


Evaluation Of Late Season Potassium Applications To Arkansas Soybean, Carrie Ortel May 2024

Evaluation Of Late Season Potassium Applications To Arkansas Soybean, Carrie Ortel

Graduate Theses and Dissertations

Potassium (K) deficiency is one of the most important yield limiting factors in Arkansas soybean (Glycine max (L.) Merr.) production, although there are recently improved diagnostic and management opportunities available. However, several questions regarding the successful implementation of in-season K management in soybean production remain. Therefore, the research objectives were to (a) delineate the relationship between drought stress and K deficiency on soybean vigor, (b) identify the spatial dependencies of leaf-K concentrations at the production scale, (c) develop a leaf sampling protocol, (d) calibrate the fertilizer-K rate needed to correct varying levels of K deficiency at 15, 30, and …


Development Of Genomic Resources And Group Specific Markers For Evaluation Of Genetic Diversity Of Pathogenic Rhizoctonia Species, Juanita Gil Bedoya Dec 2023

Development Of Genomic Resources And Group Specific Markers For Evaluation Of Genetic Diversity Of Pathogenic Rhizoctonia Species, Juanita Gil Bedoya

Graduate Theses and Dissertations

Rhizoctonia is a complex genus in the phylum Basidiomycota comprised of several taxa distributed across different families in the order Cantharellales. Many species in the genus have been identified as plant pathogens, saprobes, or beneficial mycorrhizal symbionts of orchids. Rhizoctonia isolates are divided into binucleate and multinucleate and then classified into anastomosis groups (AGs) based on the ability of compatible hyphae to fuse. Binucleate Rhizoctonia species (Ceratobasidium spp.) are classified into 21 AGs identified with letters (AG-A to AG-U). Multinucleate Rhizoctonia species (Thanatephorus spp.) are identified with numbers and classified into 14 anastomosis groups (AG-1 to AG-13, and bridging group …


Assessing The Evaporation Method For Soil-Water Retention Curve Development And Comparison Of Soil-Water Characteristics Across Different Tillage Practices In A Furrow-Irrigated Corn (Zea Mays L.) System, Jeferson Prass Pimentel Dec 2023

Assessing The Evaporation Method For Soil-Water Retention Curve Development And Comparison Of Soil-Water Characteristics Across Different Tillage Practices In A Furrow-Irrigated Corn (Zea Mays L.) System, Jeferson Prass Pimentel

Graduate Theses and Dissertations

The thesis comprises three studies. The first study in this thesis (Chapter I) focused on a six-year corn field experiment to assess the influence of conservation agricultural practices on soil properties and their long-term effects on water-use efficiency and yield. Non-tillage management did not significantly reduce soil bulk density compared to conventional tillage, as no differences were observed between non-tillage and tillage systems throughout the 6-year experiment. There was no difference in total water-use efficiency among soil management practices in 2018, 2019, 2020, and 2021. Even though in one year of the study, a significant 24 kg ha-1 mm-1 improvement …


Cellular Control Of Proteostasis, Cytoskeleton Organization, And Polarity Remodeling During Infection-Related Development By The Rice Blast Fungus, Audra Rogers Dec 2023

Cellular Control Of Proteostasis, Cytoskeleton Organization, And Polarity Remodeling During Infection-Related Development By The Rice Blast Fungus, Audra Rogers

Graduate Theses and Dissertations

Understanding the intricate processes underlying fungal infection-related development is crucial for combating plant pathogens. In this study, we investigate the coordination of morphogenetic transitions during plant infection by Magnaporthe oryzae, the blast fungus. We focus on three key aspects: protein quality control, cytoplasmic microtubule organization, and cell-end marker proteins. M. oryzae forms a specialized infection cell known as an appressorium. The proper formation of this cell is crucial for the pathogen to infect a susceptible host. First, we investigate protein quality control mechanisms during infection-related development. Our findings demonstrate that aggregated proteins are sequestered into quality control compartments within conidia …


Environmental And Agronomic Evaluation Of Struvite In Rice Production Systems, Diego Della Lunga Dec 2023

Environmental And Agronomic Evaluation Of Struvite In Rice Production Systems, Diego Della Lunga

Graduate Theses and Dissertations

Furrow-irrigation constitutes an alternative water regime that has been increasingly adopted in Arkansas. Among the management of nutrients in furrow-irrigated systems, phosphorus (P) represents a substantial challenge. The environmental sustainability of rice (Oryza sativa) production systems needs to be evaluated across different water regimes and fertilizer-P sources. Therefore, the objectives of the following studies were to: i) evaluate season-long carbon dioxide (CO2) and methane (CH4) emissions and global warming potential (GWP) under different tillage treatments [i.e., conventional tillage (CT) and no-tillage (NT)] and at different site positions (i.e., up-, mid-, down-slope) along the predominant slope of a production-scale, furrow-irrigated rice …


Evaluation Of Water Hardness And Ph On Soybean And Cotton Insecticide Efficacy, Taylor Davis Dec 2023

Evaluation Of Water Hardness And Ph On Soybean And Cotton Insecticide Efficacy, Taylor Davis

Graduate Theses and Dissertations

Insecticide efficacy often varies by location and year. Many factors can influence an insecticide’s efficacy, but an often-overlooked factor is the quality of water in a carrier solution. Water quality includes many parameters, but two important ones are water hardness and pH. Research has shown that water hardness and pH can affect some pesticides. Multiple experiments were conducted to evaluate the impact of water hardness and pH on insecticide efficacy. Experiments were conducted to evaluate the impact of water hardness and pH on the efficacy and residual control of chlorantraniliprole for the control of corn earworm, Helicoverpa zea (Boddie). Leaf …


Evaluation Of Oxyfluorfen For Use In Roxy Rice, Casey Hunter Arnold Dec 2023

Evaluation Of Oxyfluorfen For Use In Roxy Rice, Casey Hunter Arnold

Graduate Theses and Dissertations

Mid-southern U.S. rice (Oryza sativa L.) producers are challenged every year to control problematic barnyardgrass [Echinochloa crus-galli (L.) Beauv.] and weedy rice (Oryza sativa L.) because they have evolved resistance to most labeled herbicides. Oxyfluorfen is a Herbicide Resistance Action Committee (HRAC)/Weed Science Society of America (WSSA) Group 14 herbicide that inhibits protoporphyrinogen oxidase within the plant. Currently, there are no HRAC/WSSA Group 14 herbicides labeled for barnyardgrass or weedy rice control in midsouthern rice production. Therefore, oxyfluorfen is being evaluated for barnyardgrass and weedy rice control. Plant breeders at the University of California – Davis were able to breed …


Economic Analysis Of Sod-Seeded Summer Annuals For Forage And Grazing, Ivanelle Meyer Dec 2023

Economic Analysis Of Sod-Seeded Summer Annuals For Forage And Grazing, Ivanelle Meyer

Graduate Theses and Dissertations

Forage and pasture trials were conducted over the summers of 2021 and 2022 to assess how forage production and nutritive value of sorghum sudangrass, cowpea, and sorghum sudangrass-cowpea mixtures, sod-seeded to bermudagrass pasture would impact stocker cattle performance. The forage trials compared forage production and quality when poultry litter was surface or sub-surface applied biennially in comparison to a no poultry litter control. Poultry litter is a nutrient dense fertilizer utilized on pastures in the mid-southern United States to increase forage nutritive value and yield. Broadcasting poultry litter results in more nutrient losses due to runoff and nitrogen volatilization compared …


Management Zone Delineation For Variable-Rate Seeding In Production Soybeans, Ujjwal Sigdel Dec 2023

Management Zone Delineation For Variable-Rate Seeding In Production Soybeans, Ujjwal Sigdel

Graduate Theses and Dissertations

Soybean seeding rate (SR) is selected according to planting date, maturity group, soil properties, and yield goal. Even though one SR is applied in most fields, site-specific adjustments with variable-rate seeding (VRS) technology can help optimize production. The project goal was to determine if VRS could be beneficial to soybean producers in Arkansas. The project objectives were to i) assess planter performance and soybean yield response to five seeding rate treatments, ii) characterize the drivers of yield variability, and iii) create a-posteriori prescription maps for VRS. Five SR treatments (185,000, 247,000, 309,000, 370,000 and 432,000 seeds ha-1) were applied using …


Evaluation Of Weed Control Efficacy And Crop Tolerance To Florpyrauxifen-Benzyl Coated Onto Urea, Bodie Lyn Cotter Dec 2023

Evaluation Of Weed Control Efficacy And Crop Tolerance To Florpyrauxifen-Benzyl Coated Onto Urea, Bodie Lyn Cotter

Graduate Theses and Dissertations

Frequent off-target movement occurrences to soybean [Glycine max (L.) Merr.], rice (Oryza sativa L.) injury, and a lack of barnyardgrass [Echinochloa crus-galli (L.) P. Beauv.] control followed the commercial launch of florpyrauxifen-benzyl in 2018. Florpyrauxifen-benzyl is a synthetic auxin, Herbicide Resistance Action Committee (HRAC)/Weed Science Society of America (WSSA) Group 4 herbicide used for postemergence weed control in rice and labeled for application at 30 g ae ha-1. Previous research documented that soybean was susceptible to injury following spray applications of florpyrauxifen-benzyl at less-than-labeled rates, and certain varieties of rice are less tolerant to spray-applied florpyrauxifen-benzyl at 30 g ae …


Effect Of Cultural Strategies And Application Technologies On Weed Control In Flooded And Furrow-Irrigated Rice, Noah Hunter Reed Dec 2023

Effect Of Cultural Strategies And Application Technologies On Weed Control In Flooded And Furrow-Irrigated Rice, Noah Hunter Reed

Graduate Theses and Dissertations

Weed control is a major problem that rice (Oryza sativa L.) producers face in the Mid-south every growing season. Restricted use of some rice herbicides has also highlighted the need for more research to be conducted on cultural weed control strategies and application technologies in rice. The aim of these studies was to evaluate rice weed control using various rice row widths, bed widths (irrigation-furrow spacing), rice cultivar selection, and nozzle type selection. Three field experiments were conducted in 2021 and 2022 across four sites at Lonoke, AR, Pine Tree, AR, Rohwer, AR, and Stoneville, MS. In experiment one, as …


Electrochemically Precipitated Struvite Effects On Soil Property And Crop Response, Tatum Simms Aug 2023

Electrochemically Precipitated Struvite Effects On Soil Property And Crop Response, Tatum Simms

Graduate Theses and Dissertations

Phosphorus (P) is a vital resource that is finite and only mineable in raw-material form in a few countries worldwide. Struvite (MgNH4PO4·6H2O) is a mineral that can be produced from wastewater that may provide a promising alternative source of fertilizer-P for crop production, but comprehensive characterizations of struvite behavior in various soils and responses of various crops are necessary. This study aimed to determine the (1) leaching potential, (2) vertical soil profile-P distribution, (3) wheat (Triticum aestivum), corn (Zea mays), and soybean (Glycine max) response, and (4) soil property changes over time of electrochemically precipitated struvite (ECST) compared to that …


Effect Of Nanobubble-Oxygenated Water For Irrigation Of Sand-Based Golf Course Putting Greens, Eric Deboer May 2023

Effect Of Nanobubble-Oxygenated Water For Irrigation Of Sand-Based Golf Course Putting Greens, Eric Deboer

Graduate Theses and Dissertations

Nanobubbles (NBs) are sub-micron, stable cavities of gas. The properties of NBs theoretically allow long bubble residence times and high gas dissolution rates resulting in the supersaturation of oxygen in water. Adequate soil aeration is a constant concern for producers of agricultural and horticultural crops. Because of their unique properties, NBs have been investigated for oxygenating water used in the irrigation of various agricultural and horticultural crops to increase soil oxygen concentration. Creeping bentgrass (Agrostis stolonifera L.) is the most widely used turfgrass for golf course putting green surfaces. Golf course superintendents use various methods to increase soil oxygen in …


Investigating Effect Of Seed Source And Developing Germination Protocols To Improve Success In Restoration Of Arkansas Tallgrass Prairies, Rhiannon Spencerosa May 2023

Investigating Effect Of Seed Source And Developing Germination Protocols To Improve Success In Restoration Of Arkansas Tallgrass Prairies, Rhiannon Spencerosa

Graduate Theses and Dissertations

American tallgrass prairie has faced losses estimated at 87-98% of original land area since European settlement. Native seeds are often used to supplement struggling or extinct plant populations in tallgrass prairie restoration and establishment sites. Two main considerations in restoration and establishment are from where to source seed and how to obtain high germination rates. In order to determine the effect of seed source, a common garden experiment was performed in Fayetteville, Arkansas in 2022 with five prairie species: Andropogon gerardii (big bluestem), Bouteloua curtipendula (sideoats grama), Panicum virgatum (switchgrass), Schizachyrium scoparium (little bluestem), and Sorghastrum nutans (Indiangrass). Seed was …


Biology, Monitoring, Sampling, And Management Of Rice Billbug, Sphenophorus Pertinax, In Furrow-Irrigated Rice, Chase Alan Floyd Dec 2022

Biology, Monitoring, Sampling, And Management Of Rice Billbug, Sphenophorus Pertinax, In Furrow-Irrigated Rice, Chase Alan Floyd

Graduate Theses and Dissertations

Furrow-irrigated rice hectares have increased annually for the last five years in the predominant long-grain rice producing states. Initial implementation of the system began in the 1980’s, but lack of rice blast (Magnaporthe grisea, Hebert) resistant cultivars made the system a nonviable option for rice producers. Hybridization of rice cultivars with less susceptibility has begun to increase the interest of producers to implement a furrow-irrigated rice production system due to the cost saving opportunities that it may provide. Elimination of the flood from large sections of the rice fields in a furrow-irrigated system alters management strategies and pest complexes compared …


Evaluation Of Biological And Chemical Seed Treatments For Management Of Rice Diseases, Sherif Adam Sharfadine Dec 2022

Evaluation Of Biological And Chemical Seed Treatments For Management Of Rice Diseases, Sherif Adam Sharfadine

Graduate Theses and Dissertations

Rice is the primary staple for more than half of the global population and is the second most important cereal worldwide. In the US, rice is primarily grown in the southern states, with Arkansas leading production and responsible for 47% of the total rice production in the country. Diseases cause significant yield losses in rice. Sheath blight, rice blast and bacterial panicle blight are the main diseases in rice and cause significant yield losses. Sheath blight alone could cause up 50% yield loss in heavily damaged fields with highly susceptible cultivars. Additionally, rice seed and seedling diseases primarily caused by …


Nitrogen Management In Rice Under Suboptimal Soil Conditions, Payton Suzanne Rhea Dec 2022

Nitrogen Management In Rice Under Suboptimal Soil Conditions, Payton Suzanne Rhea

Graduate Theses and Dissertations

In Mid-South rice (Oryza sativa, L.) production, nitrogen (N) fertilizer management for pureline varieties is most often recommended as a single preflood (SPF) or two-way split (2WS) application in a direct-seeded, delayed-flood system. Most of the N fertilizer is typically applied at the four- to six-leaf stage onto dry soil, and the second application, if necessary, into the floodwater during early reproductive growth stages (referred to as midseason). Environmental factors frequently prohibit growers from applying early N fertilizer under optimal dry soil conditions. A study was conducted to determine the best N fertilization management practices to utilize in rice when …


Applying A Material Science Approach To Improve Rice Processing Performance, Michelle Oppong Siaw Dec 2022

Applying A Material Science Approach To Improve Rice Processing Performance, Michelle Oppong Siaw

Graduate Theses and Dissertations

Rice is typically consumed as whole kernel, which makes the economic value of whole kernels twice that of brokens. Macro-structural defects such as fissures and chalkiness have been recognized to weaken kernel mechanical strength, and thereby increase breakage during milling. However, high percentages of brokens are sometimes recorded even though these defects are controlled prior to milling. It was hypothesized that rice milling characteristics are influenced by endosperm porosity from the structural arrangement of chemical components and by bran thickness and composition. Thus, this study aimed to modify chemical components by applying treatments to alter rice porosity and its associated …