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The Fight For Rice: Understanding How Monte Cristi Will Respond To Dr-Cafta And Climate Change, Scarlette G. Flores

Environmental Studies Senior Theses

The Dominican Republic and Central American Free Trade Agreement, or DR-CAFTA, was signed on March 1, 2007 by the United States, the Dominican Republic and six other countries in Central America. The United States set specific tariff schedules to be phased in after twenty years for certain crops, one of which is rice. Rice is one of the most important crops in the Dominican Republic and produced in the northwestern province of Monte Cristi. This area is affected by climate change due to droughts and water shortages. In my research, I investigate how rice farmers and agrochemical companies, two important …

An Economic Analysis In Relation To Aspects Of Kale And Rice Agricultural Production In South Carolina And The Broader Southeastern U.S., Shane Behler

All Theses

Agriculture has been crucial to the economic and cultural well-being of South Carolina throughout the state’s storied history. This importance has not diminished in our contemporary world. Agribusiness, which includes the agriculture and forestry sectors, is the largest industry in the state, providing nearly 260,000 jobs and 51.8 billion in annual economic impact. Almost 25,000 working farms encompass 4.8 million acres of land in South Carolina .

It is no stretch to claim that South Carolina’s agricultural industry affects almost every individual in the state. If not directly involved in the agriculture industry, it is nearly certain all residents have …

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 …

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 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 …

Representativeness Evaluation Of Delta-Flux Eddy Covariance Towers For Assessing Greenhouse Gas Emissions From Rice Fields In The Mid-South Region, Katherine Skiles

Biological and Agricultural Engineering Undergraduate Honors Theses

Rice grown in 5 states across the Mid-South (AR, LA, MS, TX, and MO) account for nearly 80% of all domestic U.S. rice production. Methane emissions produced during rice farming and the large seasonal water demand to maintain flooded fields have created a need for alternative irrigation research that can reduce methane emissions and conserve water. Structures called eddy covariance towers (ECTs) can observe methane and other flux responses to changing irrigation styles, and their data is shared across flux tower networks such as Delta-Flux in the Mid-South. The Delta-Flux network is relatively new, and its data-sharing capacity is not …

Examining The Benefits Of Using Rainfall To Supplement Alternate Wetting And Drying Irrigation In Zero-Grade Rice Fields In Central Arkansas, Leo Black

Biological and Agricultural Engineering Undergraduate Honors Theses

Arkansas farmers account for more than 50% of United States production of rice, a crop that requires 3 to 5 times as much water as other regional crops. Methods of reducing water use and increasing its efficiency are being explored throughout the rice production industry, including irrigation management, better land grading, and precipitation capture. This project investigates the combination of these methods. The objectives of this project were to assess field-level water inputs, identify relationships between rice growth and water input, and analyze weather patterns in zero-grade fields in central Arkansas. Subsequent results were used to determine if there is …

Phenotypic And Genotypic Characterization Of Grain Quality In Rice And Implications For Breeding, Raul A. Guerra-Lacayo

LSU Doctoral Dissertations

Rice will continue to be a staple food for the foreseeable future, and plant breeding can foment the resilience of this crop. Applied breeding programs with clear objectives can effectively develop varieties that satisfy stakeholder needs. The majority of U.S.-produced rice is destined to export markets, and Latin America is the largest importer of U.S. rice, receiving 59% of total exports in 2021. Since 2010, Latin American importers voiced concerns about the quality of U.S. rice, mainly the high chalk content of milled rice and the stickiness of cooked rice. To address these issues, the objectives of this project were: …

From Grain To Main And Following Fish, Nathan Huynh

Standard Theses

Two story maps. One is about the rice-to-shrimp agricultural transition in Vietnam from the 1970s-1990s. The other is about Senegalese fishermen climate migrants and their impact on Spain.

Targeted Mapping Of Oryza Sativa Chilling Tolerance Candidate Genes Using Multiple Stress-Relevant Quantitative Traits, Naoki Simon Shimoyama

Dissertations (1934 -)

Developing chilling tolerant accessions of domesticated Asian rice is a potential source of significant crop improvement to address the needs of a growing global population. The uniquely chilling sensitive nature of the tropically originating Oryza sativa make it the most important staple crop that could gain the maximum benefit from improved tolerance to low temperature stress. However, mechanisms underlying this complex trait are not fully understood. Oryza sativa has two major varietal groups with different levels of chilling tolerance, JAPONICA and INDICA, providing an ideal tool to investigate mechanistic differences in the chilling stress tolerance responses within this important crop …

Exploring The Effects Of Environmental Factors On Rice Blast Disease, April Ellen Lamb

Theses and Dissertations--Plant Pathology

Rice blast disease, caused by the ascomycete fungus Magnaporthe oryzae, occurs in over 85 countries and results in an annual crop loss of 10-30%, a corresponding nutrient value of meals for 60 million people. As a result, it is listed as a critical plant disease by the United Nations. Understanding factors affecting disease severity is of critical concern for food security. M. oryzae has been used as a model system for studying effector-triggered immunity (ETI) by understanding that ETI is primarily a plant response. M. oryzae has been used as a model to study fungal pathogenicity, host specificity, genome …

Expanding The Use Of High-Performance Liquid Chromatography For Varietal Identification Or Verification Of Selected Cereal Crops, Johnna Jorgensen

Electronic Theses and Dissertations

High-performance liquid chromatography (HPLC) is a form of analytical chemistry where adsorption is a key factor in which the purpose is to separate, identify and quantify each component in a mixture. It is the optimal separation technique of chemical and biological compounds that are non-volatile including proteins and natural products (i.e., plant extracts). As each sample component interacts differently with the absorbent material within the column, the flow rates change leading to the separation of peaks, which are plotted via computer software. Most commonly HPLC analysis has been used for chemical manufacturing and pharmaceutical purposes. When using HPLC for crop …

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 …

Diagnosing Excess Nitrogen In Rice Using Post-Season Tissue Samples, Kyle Hoegenauer

Graduate Theses and Dissertations

Proper nitrogen (N) management in rice production can be difficult to achieve without the aid of tools such as soil and tissue tests. There are no tests currently available to rice producers that determine whether N has been managed properly throughout the season or that detect instances of over fertilization. Rice stalk samples were collected from N response trials within 3 days of harvest from the primary Arkansas rice growing region in 2016-2018. Stalk samples were analyzed for N concentration through a KCl extraction and spectrofluorometric quantification. Samples analyzed with leaf material intact contained statistically different N concentrations than samples …

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 …

Role Of Plasma Membrane Intrinsic Proteins (Pips) Subfamily And Sulfur Nanoparticle Interactions In Metalloids Transport And Tolerance/Sensitivity In Rice, Ahmed Gm Ali

Doctoral Dissertations

Plasma membrane intrinsic proteins (PIPs) are major intrinsic proteins (MIPs) with the ability to permeate water and small uncharged solutes as well as metalloids including arsenic (As), through the cell membranes. Arsenic is a highly toxic element that occurs naturally in the earth's crust or from anthropogenic activities with a severe poisonous effect on most living organisms. Rice, as the daily staple food for more than half of the world population, accumulates higher As contents than any other economic crop due to its growing conditions in flooded paddy fields. Members from the NOD26-like intrinsic proteins (NIP) subfamily of MIP were …

The Effect Of Water Management And Ratoon Rice Cropping On Methane Emissions And Harvest Yield In Arkansas, Marguerita Leavitt

Graduate Theses and Dissertations

Sustainable intensification of rice farming is crucial to meeting human food needs while reducing environmental impacts. Rice produces 8% of all anthropogenic CH4, which is a potent greenhouse gas. CH4 emissions can potentially be reduced by cultivation practices that minimize the number of days the fields are saturated, such as dry-seeding instead of water-seeding and irrigation using the alternate wetting and drying (AWD) technique instead of delayed, continuous flooding (DF). Ratoon cropping, wherein a second crop of rice is grown from the harvested stubble of the first crop, can be used to produce additional yield with minimal labor, but may …

Genetic Dissection And Qtl Pyramiding To Enhance Salinity Tolerance In Rice (Oryza Sativa L.), Sandeep Chapagain

LSU Doctoral Dissertations

Salinity is emerging as a major threat to rice production worldwide due to climate change and anthropogenic sources. We performed three different population development approaches using exotic salt tolerant donors in US rice backgrounds to identify the salt tolerant QTLs/genes and tolerant breeding lines. First approach involved development of a biparental introgression lines (ILs) population by utilizing a salinity tolerant donor ‘TCCP’ in an elite rice cultivar ‘Cheniere’ background and mapping of QTLs at germination, seedling, and reproductive stages A total of seven QTLs for five germination traits, 16 QTLs for seven seedling stage traits, and 30 QTLs for ten …

Evaluation Of Benzobicyclon In Midsouth Rice (Oryza Sativa) Production Systems, Jake Patterson

Graduate Theses and Dissertations

Controlling weedy rice postemergence is challenging for rice producers in the United States because of the lack of herbicide options. Weedy rice is genetically similar to cultivated rice, thus making it difficult to control with mid-season postemergence herbicide applications without also damaging the crop. Hence, there is a need for a new effective postemergence weedy rice control herbicide. Findings from this research indicate that the use of benzobicyclon in current standard quizalofop- and imidazolinone-resistant rice herbicide programs provides tremendous utility for Midsouth rice producers. In both of these production systems, the addition of benzobicyclon to the respective standard herbicide programs …

Impact Of New Technologies On Weed Control In Louisiana Rice Production, David C. Walker

LSU Doctoral Dissertations

Field studies were conducted in 2018-2021 at the LSU Agricultural Center’s H.R. Caffey Rice Research Station (RRS) near Crowley, LA, and the Dean Lee Research and Extension Center (DLREC) near Alexandria, LA to evaluate off-target florpyrauxifen movement on soybean. Soybean was treated with florpyrauxifen at the V4-V5 or R1-R2 growth stages. Soybean injury was evaluated at 1, 7, 14, and 28 days after treatment (DAT) and soybean plant height (cm) was recorded at 7, 14, and 28 DAT. At soybean maturity, yield and individual yield components were subjected to regression analysis to describe the relationship between florpyrauxifen rate and soybean …

The Three-Way Interplay Among Early Life Exposures, The Gut Microbiome, And Outcomes In Infancy, Yuka Moroishi

Dartmouth College Ph.D Dissertations

The bidirectional relationship between the gut microbiome and immune system plays an important role in host immune status: the immune system provides the gut microbiome the optimal environment to thrive in, and the gut microbiome helps regulate the immune system. This relationship is especially important in infants, whose immune system is still premature and rely on innate immunity.

We investigated the three-way interplay among early-life exposures, the developing gut microbiome, and outcomes in infancy from the general population in New Hampshire, US. We used prospective cohort data from the New Hampshire Birth Cohort study to 1) determine whether timing of …

Evaluation Of Alternate Wetting And Drying Irrigation Management In Rice, Richard Lee Atwill Ii

Theses and Dissertations

Water level declines in the Mississippi River Valley Alluvial Aquifer (MRVAA) are attributed largely to withdrawals for rice (Oryza sativa L.) irrigation. This study was performed to determine if alternative irrigation strategies for rice could reduce withdrawal from the MRVAA without having an adverse effect on grain yield, grain quality, control of barnyardgrass, and profitability. Research was conducted in Stoneville, MS and 19 on-farm locations across the Delta region of Mississippi from 2014 through 2017 to determine the irrigation threshold for alternate wetting and drying (AWD) rice irrigation, the effect of AWD management on barnyardgrass control, and effects of …

Evapotranspiration In Mid-South Rice Production, Colby Wade Reavis

Graduate Theses and Dissertations

Rice provides much needed sustenance to a large portion of the global population, particularly in the developing world. With stress placed on food production systems under the reality of climate change and an increasing global population, rice production systems require solutions to a number of issues, including a limited water supply. As producers explore new strategies for conserving local water resources to continue to maintain yields, new irrigation strategies and technologies are being developed and validated for use at commercial production scales. Alternate wetting and drying (AWD) is an irrigation practice that provides water savings through the capture of rainfall …

Data Analytics For Sustainable Food And Agriculture Systems, Megan Lord Reavis

Graduate Theses and Dissertations

The increasing concentration of anthropogenic greenhouse gases in the atmosphere is altering the climate, posing a serious threat to global agriculture and food security. Agriculture and food production contribute a quarter of all GHG emissions produced, so there is a critical need to limit emissions in this area while increasing food production to feed the anticipated 10 billion people by 2050. To address the needs of the future, data-driven solutions are needed to guide decision-making and provide support for actionable climate mitigation and survival strategies. Research efforts must be focused on analyzing problems on multiple scales, identifying new ways to …

Mitigating Rice Injury Caused By Florpyrauxifen-Benzyl And Optimizing Florpyrauxifen-Benzyl Rate And Timing For Use In Furrow-Irrigated Rice, James Winston Beesinger

Graduate Theses and Dissertations

Florpyrauxifen-benzyl (synthetic auxin, WSSA Group 4) is a postemergence, broad-spectrum herbicide labeled for use in Mid-South rice (Oryza sativa L.) production. Introduction of florpyrauxifen-benzyl to Arkansas rice production led to observations of varying levels of injury caused by the herbicide across cultivars and environments. Findings from previous research indicated hybrid long-grain rice and medium-grain rice were more susceptible to florpyrauxifen-benzyl and hypotheses were formed using this research regarding the impact of environmental conditions on the amount of injury observed. Concerns of yield loss, delay in maturity and loss of groundcover as well as questions regarding the ability of florpyrauxifen-benzyl to …

Impact Of Planting Arrangement And Drill Row Spacing For Direct-Seeded, Delayed Flood Rice, Mary Jane Lytle

Graduate Theses and Dissertations

Direct-seeding is the most frequently utilized planting practice in Arkansas and Mid-South rice (Oryza sativa L.) production. Enhanced plant density and more rapid rice canopy formation may result from the implementation of innovative plant arrangements and spacings. Studies were initiated in 2019 and continued into 2020 to examine different cultural management practice experiments, including evaluating the impacts of planting arrangement, row spacing, and seeding rates on rice stand density, canopy coverage, grain yield, and milling yield. These small-plot trials were conducted at two locations, a silt loam site and a clay site, representative of soils produced to rice in eastern …

Precise Nitrogen Recommendations Improve Economic And Environmental Outcomes In Arkansas Rice Production, Cristin Roberts

Graduate Theses and Dissertations

Soil testing has become an increasingly important tool in making agronomically efficient production management decisions. N-STaR is a N test used in rice production and is unique in its ability to selectively quantify soil organic-N compounds which are readily mineralizable for plant N uptake and contribute to growth and yield. This study uses historical (2002–2018) adoption rates of N-STaR, which is funded through Rice Checkoff funds, to calculate the total cost savings from N-STaR adoption. These cost savings alone would be the “typical” benefits used in a benefit-cost ratio of a public ally funded research program like N-STaR. However, we …

Understanding The Influence Of Zinc On Grain Cadmium Accumulation And Bioaccessibility In Rice, Michael A. Tavarez

Dissertations, Theses, and Capstone Projects

The effect of cadmium and zinc on mineral concentrations in three cultivars of rice

Interactions between the essential mineral zinc (Zn) and the toxic heavy metal cadmium (Cd) play an important role in regulating transport of both minerals to rice grains. Understanding these interactions is crucial for limiting cadmium and increasing zinc transfer to the food chain. Previous studies on the matter have had conflicting results suggesting synergistic and antagonistic relationships between the minerals. The goal of this work was to identify the effect of external cadmium and zinc on the uptake and translocation of both minerals from roots to …

Weedy Rice (Oryza Sativa Ssp.): An Untapped Genetic Resource For Abiotic Stress Tolerant Traits For Rice Improvement, Shandrea D. Stallworth

Theses and Dissertations

Rice (Oryza sativa) is the staple food for more than 3.5 billion people worldwide. As the population continues to grow, rice yield will need to increase by 1% every year for the next 30 years to keep up with the growth. In the US, Arkansas accounts for more than 50% of rice production. Over the last 68 years, rice production has continued to grow in Mississippi, placing it in fourth place after Arkansas, Louisiana, and California. Due to increasing rice acreage, regionally and worldwide, the need to develop abiotic stress-tolerant rice has increased. Unfortunately, current rice breeding programs lack genetic …

The Rainforest Is Burning: Trials And Triumphs Working Towards Conservation In Rural Madagascar, Kathryn Alessi

Dissertations, Theses, and Capstone Projects

In late 2019, I spent almost four months in Ranomafana, Madagascar, a region in the southeast that houses tropical rainforest. The research I conducted is not analyzed in this capstone. Instead, I decided to write about my personal experience through a series of reflections that explore the difficulties I faced, as well as the moments of joy. Much of the information presented in this capstone and white paper come from my own experience and copious conversations I had with other people in Madagascar. Several of these conversations were recorded in my diary and fieldnotes, but most were recounted from my …