Digital Commons Network^™

The Role Of African Leafy Vegetables In Food Security, Marcia M. Croft

Open Access Dissertations

African leafy vegetables (ALVs) are a diverse set of crops grown across sub-Saharan Africa. They have been a staple of traditional diets and contain many critical micronutrients but their importance has been largely ignored by researchers and policymakers at the expense of imported crops. Availability, accessibility, and utilization of ALVs are limited by factors across the supply chain. This research investigated seed systems, drought tolerance, hydroponic production, market barriers, consumer preference, and the impact of gender as related to ALVs. We found that ALVs play an important role in food security and that critical differences exist between formal and informal …

Managing Bacterial Wilt, Caused By Erwinia Tracheiphila, On Muskmelon With Early Control Of Striped Cucumber Beetle ( Acalymma Vittatum (F)), And Through Varietal Selection, Ahmad Shah Mohammadi

Open Access Dissertations

Muskmelon (Cucumis melo L), is an important vegetable crop in the United States. It is grown throughout the US, and Indiana ranked 4th in production after California, Arizona and Georgia with 12.4 thousand metric tons and market value of $7.6 million in 2015. Bacterial wilt of cucurbits, which is caused by Erwinia tracheiphila (E. F. Smith), and vectored by striped cucumber beetle (Acalymma vittatum (F)), is one of the most serious diseases of muskmelon that influences muskmelon quality and yield. Many cultivars of muskmelon are grown around the United States, especially in the Midwest. Muskmelon cultivars differ in …

The Relationship Between Protein And Phosphorus Digestion And Retention In Growing Pigs And Broiler Chickens, Pengcheng Xue

Open Access Dissertations

Xue, Pengcheng. Ph.D., Purdue University, December 2016. The Relationship between Protein and Phosphorus Digestion and Retention in Growing Pigs and Broiler Chickens. Major Professor: Dr. Layi Adeola. The objective of this study was to investigate the relationship between protein and P digestion and retention in growing pigs and broiler chickens. The methodology of determining the digestibility of AA and P and the effect of dietary N and P on the digestion and retention of these two nutrients were investigated.

An experiment was conducted in growing pigs to investigate the additivity of AID or SID of CP and AA in mixed …

Subsidies, Aquaculture Technology Adoption, And Welfare Impacts In Ghana And Kenya, Akuffo Amankwah

Open Access Dissertations

This dissertation empirically examines subsidies, aquaculture technology adoption, and welfare implications of fish farming households in Ghana and Kenya. It is divided into three separate chapters, each addressing a specific empirical issue related to aquaculture in the countries.

The second chapter of this dissertation applies the lognormal double hurdle model to a cross-section of fish farms to analyze commercial demand for improved feed, and whether the government feed subsidy program influences private demand for the feed. The results indicate that households’ decisions to participate in improved feed market are affected by the quantity of the subsidized feed received. Once the …

A Unique Perspective On The Demand For Livestock Product Attributes, Elizabeth S. Byrd

Open Access Dissertations

Consumers are increasingly concerned about the social and environmental impacts of the foods they purchase. Both choice experiments and best-worst scaling (BWS) methodology have been used to elicit consumer willingness to pay (WTP) for food attributes and the relative importance of food attributes to consumers. The dissertation consists of four essays. Chapter 2 presents a formal law review article exploring the laws associated with wild game harvest, consumption, and inspections. The remaining three essays (Chapters 3-5) each address an extension or application of choice experiment and/or BWS methodology focused on credence attributes of meat products. Two online surveys were used …

Essays On Malawian Agriculture: Micro-Level Welfare Impacts Of Agricultural Productivity; Profitability Of Fertilizer Use; And Targeting Of Fertilizer Subsidy Programs, Francis Addeah Darko

Open Access Dissertations

This dissertation comprises of three essays that address different aspects of agriculture in Malawi using a two-wave panel data collected by the National Statistical Office of Malawi with support from the World Bank Living Standards Measurement Study – Integrated Surveys on Agriculture (LSMS-ISA) program. Each essay stands alone as an independent study because of differences in research questions and the methodologies used in addressing the questions.

The first essay analyzes the micro-level welfare impacts of agricultural productivity. Welfare is measured by various dimensions of poverty and food insecurity; and agricultural productivity is measured by maize yield and value of crop …

The Biology And Management Of Palmer Amaranth (Amaranthus Palmeri S. Wats) In Indiana, Douglas J. Spaunhorst

Open Access Dissertations

Palmer amaranth is a pernicious summer annual weed that has evolved resistance to six herbicide sites of action in the U.S. and threatens agriculture production. In 2011, Palmer amaranth was identified in flood plains in two southern Indiana counties (Posey and Vanderburgh). Determining if Palmer amaranth can survive and reproduce in northern Indiana may provide insight if this weed will be problematic for northern row crop producers. The objectives of our research were to identify fields containing Palmer amaranth and determine the distribution of herbicide resistance traits in Indiana; determine the influence of tillage frequency and tillage intervals on Palmer …

Food Security Crop Price Transmission And Formation In Nigeria, Patrick L. Hatzenbuehler

Open Access Dissertations

The three studies in this dissertation explore the current conditions and operations of markets for seven key food security crops (cassava, cowpeas, maize, millet, rice, sorghum, and yams) in Nigeria.

Chapter 2 is an empirical analysis of the current agricultural statistics system in Nigeria. A number of sources gather and report agricultural statistics for the country. Since there has not been an agricultural census implemented there for multiple decades, however, there is no objective source for data verification. Therefore, this study uses two additional types of “on the ground information” to assess if agricultural production estimates reflect growing conditions: prices …

Evaluating The Two-Stage Ditch As A New Best Management Practice, Andi Hodaj

Open Access Dissertations

A two-stage ditch involves modifications of a traditional drainage ditch to resemble more the features of a natural stream. The idea is to create or simulate extended benches on both sides of the ditch that would develop naturally over a period of time in a stream because of geomorphological processes. Previous research in Indiana and Ohio has shown that two-stage ditches offer the potential to reduce sediment load and extend the interaction time between water and vegetation on the benches allowing larger uptake of nutrients from the vegetation on the extended benches, and increasing the denitrification rates in the bench …

Learning From Data: Plant Breeding Applications Of Machine Learning, Alencar Xavier

Open Access Dissertations

Increasingly, new sources of data are being incorporated into plant breeding pipelines. Enormous amounts of data from field phenomics and genotyping technologies places data mining and analysis into a completely different level that is challenging from practical and theoretical standpoints. Intelligent decision-making relies on our capability of extracting from data useful information that may help us to achieve our goals more efficiently. Many plant breeders, agronomists and geneticists perform analyses without knowing relevant underlying assumptions, strengths or pitfalls of the employed methods. The study endeavors to assess statistical learning properties and plant breeding applications of supervised and unsupervised machine learning …

Three Essays Analyzing The Role Of Social Capital On Individual And Firm Decision Making, Ariana P Torres Bravo

Open Access Dissertations

The following dissertation is comprised of three essays that focus on different mechanisms on which social capital influences firm and entrepreneur behavior. All three essays use different econometric techniques to account for endogenous variables.

Essay 1: Are Local Market Relationships Trumping Organic Certification? The Case of Small and Medium Fruit and Vegetable Farmers. This article investigates how an organic fruit and vegetable farmer’s choice to use direct-to-consumer market channels impacts his/her decision to be certified organic. First, we model the decision to be certified organic as a conditionally independent decision from the farmer’s chosen market channels. Second, we estimate …

Evaluation Of Negative Energy And Mineral Balance In Periparturient Holstein-Friesian Cattle, Ameer Ahmed Abdelhameed

Open Access Dissertations

Most cows experience a state of negative energy and mineral balance during the periparturient period. This imbalance is a major problem in the dairy industry and it is more frequently seen in multiparous cattle due to their high milk production. A large amount of fat and protein is mobilized in order to address the energy deficit during the periparturient period. The ability to accurately monitor energetics and electrolytes status using accurate, rapid, and low cost point-of-care instruments will assist in optimizing animal health and productivity.

This dissertation contains three studies that evaluated point-of-care instruments for measuring blood and plasma glucose, …

Crop Modeling For Assessing And Mitigating The Impacts Of Extreme Climatic Events On The Us Agriculture System, Zhenong Jin

Open Access Dissertations

The US agriculture system is the world’s largest producer of maize and soybean, and typically supplies more than one-third of their global trading. Nearly 90% of the US maize and soybean production is rainfed, thus is susceptible to climate change stressors such as heat waves and droughts. Process-based crop and cropping system models are important tools for climate change impact assessments and risk management. As data- science is becoming a new frontier for agriculture growth, the incoming decade calls for operational platforms that use hyper-local growth monitoring, high-resolution real-time weather and satellite data assimilation and cropping system modeling to help …

Behavioral Responses And Policy Evaluation: Revisiting Water And Fuel Policies, Shanxia Sun

Open Access Dissertations

In my dissertation, I examine how policies regulating agricultural production and clean technology impact the environment. I focus on policies affecting water depletion, water pollution, and fuel consumption. I assess their cost-effectiveness by modeling and quantifying the behavioral responses of farmers and households.

My first essay focuses on decreasing groundwater depletion through increasing irrigation efficiency in Mexico. I quantify the impacts of different sources of inefficiency on groundwater extraction, and I evaluate the effectiveness of alternative policies that aim to reduce the over-extraction of groundwater. I find that mechanisms of electricity cost-sharing implemented in many wells have a sizable impact …

Enhancing Bioethanol Fermentation Through Removal Of Acetic Acid Using Liquid-Liquid Extraction, Mahdieh Aghazadeh

Open Access Dissertations

The concern for the ever growing human population as well as the depletion of fossil fuel resources and their impact on global warming have long been motivations for the researchers to investigate means for sustainable producing carbon-neutral energy. Second-generation biofuel refers to liquid fuels that are produced from non-food resources and reduce the total greenhouse gas emission by at least 60 %. Acetic acid has been shown to be one of the most ubiquitous fermentation inhibitors in a bioethanol production facility which slows down the bioethanol production and reduces its yield through inhibition of the ethanol producing microorganisms. The use …

U.S. Farm Capital Investment 1996--2013: Differences By Farm Size And Operator Primary Occupation, Sarah Stutzman

Open Access Dissertations

This study analyzes U.S. farm level investment in machinery, equipment and structures between 1996-2013. A synthetic panel is constructed using annual cross-sectional farm level observations from the Agricultural Resource Management Survey (ARMS). Cohorts are formed by grouping farms into similar categories based upon farm production type, region and farm typology. This methodology allows the use of fixed effects to control for cohort specific and time-invariant similarities in investment levels, addresses non-investment in a single period by using cohort average investment rates, and allows links between investment levels and other key determinants across cohorts over time.

Within farm typologies, farms are …

Trade And Agriculture Policy Options To Improve The Wheat Subsector In Afghanistan, Ghulam Hazrat Halimi

Open Access Dissertations

In Afghanistan wheat availability is important for national food security as it is the key staple food, accounting for over half of calorie intake. The country has imported on average 32% of its wheat consumption over the period 2000-2015, primarily from Pakistan and Kazakhstan. Since domestic production is volatile, consumer well-being depends on access to international markets.

Pakistan, a key supplier of wheat and flour to Afghanistan, has not been a reliable source for Afghanistan to meet its wheat deficit. Pakistan subsidizes and stabilizes its wheat production, and this benefited Afghan consumers before 2008. Pakistan restricted wheat and flour exports …

Hydrologic And Water Quality Impacts From Perennial Crop Production On Marginal Lands, Qingyu Feng

Open Access Dissertations

Marginal lands are proposed as a viable option for producing biofeedstocks as these lands are not heavily engaged in agricultural production or may not be suitable for intensive row-crop food/feed production. However, meeting biofeedstock production goals will require large amount of marginal lands and the unintended consequences of producing biofeedstocks on marginal lands are not fully clear. The overall goal of this study was to evaluate the productivity of biofeedstocks on marginal lands and the potential impacts on hydrologic and water quality processes from the land use conversion.

This study was conducted in the Upper Mississippi River Basin (UMRB). First, …

Modeling, Empirics And Policy Implications Of Firm Heterogeneity In International Trade, Zeynep Akgul

Open Access Dissertations

Computable General Equilibrium (CGE) models are essential computational tools for trade policy analysis. While traditional CGE models based on the Armington assumption of national product differentiation have been successfully applied to various policy scenarios, they also have significant limitations in explaining the firm-level information prevalent in the recent international trade literature. The pioneering work of Melitz (2003) has provided a firm heterogeneity theory that can help address the shortcomings of Armington-based CGE models by introducing additional productivity mechanisms and extensive margin effects. Incorporation of firm heterogeneity in mainstream CGE models offers great potential to improve computational policy analysis. Even though …

Communication, Home Bias And Social Capital, Sharon Raszap Skorbiansky

Open Access Dissertations

This dissertation consists of three essays on the effects of communication, home bias and social capital. The first study analyzes three different laboratory treatments that determine if policies that introduce and improve communication are beneficial to a market. The control treatment has no communication. Then, two different types of communication mechanisms are introduced: cheap communication, where subjects are able to lie, and truthful communication, where only honest messages may be sent. The results demonstrate that truthful communication dramatically improves subjects' ability to trade efficiently, ultimately leading to higher social surplus and lower income inequalities. Cheap communication does not produce the …

Propionate Induces Gluconeogenesis In Dairy Cattle Through Direct Activation Of The Bovine Cytosolic Phosphoenolpyruvate Carboxykinase Gene Promoter, Qian Zhang

Open Access Dissertations

Phosphoenolpyruvate carboxykinase (PCK, GTP; EC4.1.1.32) catalyzes the conversion of oxaloacetate (OAA) to phosphoenolpyruvate (PEP), a critical reaction for gluconeogenesis. The two isoforms of PCK, namely cytosolic PCK (PCK1), and the mitochondrial PCK (PCK2) are abundantly expressed in liver and kidney. Increased PCK1 activity and mRNA expression in liver is observed as feed intake recovers during early lactation in dairy cows, a condition linked to increased ruminal propionate production. The central hypothesis of this dissertation is that propionate regulates its own metabolism in liver of dairy cattle through regulation of the PCK1 gene. The objectives of this dissertation were to determine: …

Show Horse Welfare, Melissa A. Voigt

Open Access Dissertations

In recent years there has been an increase in the public's attention to situations where trainers, owners, and handlers have compromised the well-being of show horses for the sake of winning. These situations may be due to training negligence or naivety of individuals working with the horse. Either way, due to these incidents, increasing pressure has been placed on the horse industry to address show horse welfare. The purpose of this research was to expound on the welfare of stock-type show horses through the perspective of those directly involved; considering the understanding of welfare, the value placed on welfare, and …

The Use Of Oral History And Narrative Research In Broadening The Historical Foundation Of The Agricultural Communication Field, Natalie L Federer

Open Access Dissertations

The historical foundation of the agricultural communication community (consisting of both academics and the profession) is shallow and void of humanistic perspective, and there is a minimal amount of historical content that focuses on academic and professional history. The need to explore and interpret historical dimensions of this field is vital to further development of the discipline as an academic and professional field. Oral history was utilized to capture and preserve the interview content from a small sample of agricultural communication and Extension professionals and faculty while narrative research, interpretative theory, and constructivism were utilized to further understand and interpret …

Energy Production, Distribution, And Pollution Controls: Combining Engineering And Economic Analysis To Enhance Efficiency And Policy Design, David F. Perkis

Open Access Dissertations

Three published articles are presented which focus on enhancing various aspects of the energy supply chain. While each paper adopts a different methodology, all three combine engineering data and/or techniques with economic analysis to improve efficiency or policy design within energy markets. ^ The first paper combines a chemical engineering plant design model with an economic assessment of product enhancements within an ethanol production facility. While a new chemical process is shown to achieve greater ethanol yields, the animal feed by-products are denatured and decrease in value due to the degradation of a key nutritional amino acid. Overall, yield increases …

Irrigation With Treated Wastewater: Potential And Limitations, Anne Dare

Open Access Dissertations

As the world population increases and resources become more coveted, water emerges as a key component to global food security. The Middle East and North Africa (MENA) is among the driest regions in the world: containing just one percent of the world's freshwater resources. An increasing population creates greater quantities of wastewater and demands greater quantities of food, so an obvious connection arises. However logical wastewater reuse may be for bridging the irrigation supply-demand gap in this arid region, significant limitations prevent widespread adoption. The overall goal of this research is to take a holistic view of the limitations facing …

Light-Emitting Diodes As An Alternative Supplemental Lighting Source For Greenhouse Tomato Propagation And Production, Celina Gomez Vargas

Open Access Dissertations

Intensive year-round local production of greenhouse-grown tomatoes (Solanum lycopersicum L.) requires the use of supplemental lighting (SL) to complement solar radiation in light-limited seasonal climates. However, SL represents a large expense to greenhouse-vegetable production. Currently, energy is second only to labor as the most expensive indirect cost of production. Thus, the greenhouse industry is interested in cost-effective, energy-efficient sources of supplemental photosynthetic light to sustain steady supplies of high-quality produce during the off-season. Overhead (OH) high-pressure sodium (HPS) lamps are considered the industry standard in greenhouse SL because of their capability to deliver adequate photosynthetically active radiation (PAR …

The Role Of Adiponectin And The Adipocyte In Energy Metabolism And Inflammation, Sheila Kay Jacobi

Open Access Dissertations

A series of experiments were conducted to characterize the autocrine role of adiponectin in modulating fatty acid metabolism and inflammation in the pig. In the first study, we cloned and sequenced the porcine adiponectin open reading frame and evaluated the regulation of adiponectin, in vitro and in vivo. The porcine sequence shares approximately 88, 86, 85 and 83% homology with the dog, human, cow and mouse adiponectin, respectively, and 79–83% similarity with dog, human, cow and mouse proteins at the amino acid level, based on the translated porcine sequence and GenBank submissions for the other species. Analysis of serum from …

Assessment Of Irrigation Use On Crop Yield And Water Supplies In The Midwestern U.S., Wei-Chih Chen

Open Access Dissertations

Climate plays an important role in many aspects of hydrological and agricultural systems. Temperature and precipitation are usually the main forcing inputs for hydrological and agricultural simulations, while wind effect has generally been neglected in previous research. Wind speed is, however, an important factor for many physical processes, including evaporation from soil, and transpiration from plants. In order to investigate how climate variability impacts agricultural production, there are three hypotheses addressed in this dissertation. Hypothesis 1 is that the representation of changing wind speed will play an important role in the simulation of hydrological processes, and that the effect of …

African Starchy Foods, Gastric Emptying, And Starch Digestion In Malian Stunted Children, Fatimata Cisse

Open Access Dissertations

Starch serves as the main energy source in cereal and tuber-rich diets, and its glycemic response profile has been associated with health-related conditions. Sorghum and millet are known to have relatively low starch digestibility, a potentially desirable property for controlling blood glucose response and providing sustained energy. Gastric emptying rates of traditional sorghum and millet-based African foods of the Sahelian region (couscous, thick and thin porridges made from millet and/or sorghum) were compared to those of non-traditional "modern" foods that are mostly consumed in urban areas using a non-invasive 13C-labelled octanoic acid breath test in healthy volunteers. The obtained results …

Prediction Of Parturition And Dystocia In Holstein-Friesian Cattle, And Cesarean Section In Dystocic Beef Cattle, Wen Han Mark Hiew

Open Access Dissertations

Dystocia is a major problem in the dairy industry as it causes livestock and economic loss. It is more frequently seen in primiparous cattle compared to their multiparous counterparts due to their smaller stature and the slow maturation of pelvic dimensions. In some instances, human intervention of the parturition process is imperative to avoid pain, injury, and mortality of the neonate and the dam. The ability to accurately predict dystocia and the time of parturition will ensure that timely assistance can be given to animals that are of high risk of dystocia.^ The present thesis contains four studies that explore …