Agriculture Commons^™

Metabolic Engineering Of Oilseed Crops To Produce High Levels Of Novel Acetyl Glyceride Oils With Reduced Viscosity, Freezing Point And Calorific Value, Jinjie Liu, Adam Rice, Kathleen Mcglew, Vincent Shaw, Hyunwoo Park, Thomas E. Clemente, Mike Pollard, John Ohlrogge, Timothy P. Durrett

Department of Agronomy and Horticulture: Faculty Publications

Seed oils have proved recalcitrant to modification for the production of industrially useful lipids. Here, we demonstrate the successful metabolic engineering and subsequent field production of an oilseed crop with the highest accumulation of unusual oil achieved so far in transgenic plants. Previously, expression of the Euonymus alatus diacylglycerol acetyltransferase (EaDAcT) gene in wild-type Arabidopsis seeds resulted in the accumulation of 45 mol% of unusual 3-acetyl-1,2- diacyl-sn-glycerols (acetyl-TAGs) in the seed oil (Durrett et al., 2010 PNAS 107:9464). Expression of EaDAcT in dgat1 mutants compromised in their ability to synthesize regular triacylglycerols increased acetyl-TAGs to 65 mol%. Camelina and soybean …

Consumer Acceptance And Willingness To Pay For Genetically Modified Rice In China: A Double Bounded Dichotomous Choic Contingent Valuation Survey Calibrated By Cheap Talk, Jing Jin

Graduate Theses and Dissertations

Considering population growth, limitations on land and water resources, and contamination to the ecosystem due to agricultural activities, current rice production in China is facing pressure to fulfill national demand. Self-sufficiency of rice has been a long-held political objective of the Chinese government and it is national goal to maintain the equilibrium between the national production and consumption or even achieve a supply surplus in rice. With the developing bio-technology of genetic modification (GM), scientists believe that using genetically modified cultivars may ease the pressure mentioned above. However, both the government and the people are very cautious about large-scale cultivation …

Spatial Distribution And Genetic Variability Of Reniform And Lance Nematodes In Cotton Agroecosystems, Claudia Holguin

All Dissertations

Rotylenchulus reniformis (reniform nematode) and Hoplolaimus columbus (Columbia lance nematode) are two of the main plant-pathogenic nematode species affecting cotton production in the United States. For the selection and implementation of effective management practices it is important to understand distribution patterns and population genetic structure of these two nematodes in cotton agroecosystems. In a three-year field study, the spatial distribution of reniform nematode was characterized in two commercial fields in South Carolina to determine the effects of relations with soil texture and crop rotation on reniform nematode distribution (Chapter 1). Results of this project suggest that population densities of reniform …

European Consumers' Attitudes Towards Cisgenic Rice, Anne-Cécile Delwaide

Graduate Theses and Dissertations

The enhancement of existing plant breeding techniques, such as cisgenesis, allows plant breeders to enhance an existing cultivar quicker and with little to no genetic drag. Cisgenesis is the genetic modification of a recipient plant with natural gene(s) from a sexually compatible plant. Unlike transgenesis, which is the genetic modification of a recipient plant with gene(s) from any non‐plant organism, or from a donor plant that is sexually incompatible with the recipient plant, the results of cisgenesis could occur naturally over time. Currently, both cisgenic and transgenic products are classified as genetically modified organisms (GMOs) and are labeled as such …

2015 Spring Seed Guide, Teshome Regassa, Charles A. Shapiro

Department of Agronomy and Horticulture: Faculty Publications

NEBRASKA CORN HYBRID TESTS CROP PRODUCTION SUMMARY: According to the National Agricultural Statistics Service, there were 8.75 million acres of corn harvested in Nebraska in 2014 producing approximately 1.58 billion bushels of grain. The total average corn yield for Nebraska in 2014 was a record 181 bushels per acre (bu/a). Total corn yields from the previous 10 years are reported below.

NEBRASKA SOYBEAN VARIETY TESTS - 2014 - CROP PRODUCTION SUMMARY: According to the National Agricultural Statistics Service, there were 5.4 million acres of soybeans planted in Nebraska in 2014. 5.35 million acres were harvested producing around 288 million bushels. …

Functional Genomics And Microbiome Profiling Of The Asian Longhorned Beetle (Anoplophora Glabripennis) Reveal Insights Into The Digestive Physiology And Nutritional Ecology Of Wood Feeding Beetles, Erin D. Scully, Scott M. Geib, John E. Carlson, Ming Tien, Duane Mckenna, Kelli Hoover

Department of Agronomy and Horticulture: Faculty Publications

Background: Wood-feeding beetles harbor an ecologically rich and taxonomically diverse assemblage of gut microbes that appear to promote survival in woody tissue, which is devoid of nitrogen and essential nutrients. Nevertheless, the contributions of these apparent symbionts to digestive physiology and nutritional ecology remain uncharacterized in most beetle lineages.

Results: Through parallel transcriptome profiling of beetle- and microbial- derived mRNAs, we demonstrate that the midgut microbiome of the Asian longhorned beetle (Anoplophora glabripennis), a member of the beetle family Cerambycidae, is enriched in biosynthetic pathways for the synthesis of essential amino acids, vitamins, and sterols. Consequently, the midgut …

Assessing Net Returns To Blueberry Production Using A Decision Support Tool, Sokha Sok

Graduate Theses and Dissertations

The purpose of this study was to develop and assess the profitability of four highbush blueberry farming systems in the south: organic field production, conventional field production, organic high tunnel production and conventional high tunnel production. Four baseline budget scenarios, one for each system, are developed for a 15 year production period. The results suggest that under expected production and price conditions for Northwest Arkansas, while all four production systems generated positive present value of net returns, the conventional field production produced the highest present value of net returns across the 15 years. The breakeven years of production were 7 …

Litter Decomposition And Root Production In Response To Grazing On Sandhills Subirrigated Meadow, Ben W. Beckman

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

Stocking density can be manipulated by management factors including herd size, pasture size, and grazing period length. Ultrahigh stocking density (mob grazing) is commonly characterized at 200,000 kg animal live weight ha^-1 or higher with multiple movements of livestock per day. Practitioners claim increased plant production, soil development, and nutrient cycling rates because of high trampling percentages resulting from ultrahigh socking densities. This study was conducted on subirrigated meadow in the Nebraska Sandhills in 2012 and 2013 to determine grazing method effect on annual root production and litter decomposition. Stocking rates were held constant while stocking densities varied by …

Studies To Characterize Heavy Metal Content And Migration From Recycled Polyethyleneterephthalate, Michael John-Ross Whitt

Master's Theses

Packaging Materials account for 31% of the world’s municipal solid waste. Agencies like the Environmental Protection Agency (EPA) and the Agency for Toxic Substances and Disease Registry (ATSDR) are pushing for the increased use of recycled thermoplastic materials. Polyethylene terephthalate (PET) is a commonly recycled thermoplastic which is used to package ready-to-eat fruits and vegetables. Most recycled polyethylene terephthalate (RPET) packaging materials contain heavy metal catalysts, the most common being antimony. The recent increased use of recycled plastic materials has been suspected as the source of increased human heavy metal exposure. In this study, cadmium, chromium, nickel, lead and antimony …

Fearless Friday: Sean Pethybridge, Christina L. Bassler

SURGE

Talking with Sean Pethybridge ’15, one could easily assume his interest in agriculture and food justice developed at a very young age. Sean confesses that he had very limited knowledge prior to attending Gettysburg. “My grandpa had a garden and the most experience I had with that was picking green beans during the summer time when I was younger,” he jokes. [excerpt]

An Economic Analysis Of Wild Bee Pollination In Lowbush Blueberry Production, Francis A. Drummond

University of Maine Office of Research Administration: Grant Reports

The purpose of this project is to determine the relative economic values of wild bee pollinators and commercial honeybees in lowbush blueberry production for individual Maine farms. The lowbush blueberry requires insect pollination in order to set fruit. Most farmers rent colonies of the non-native honeybee for pollination services, but wild, native bees are also effective pollinators. This project aims to provide growers with the means to assess the pollination needs of individual fields and to understand the levels of pollination possible if honeybees are not available. In order to achieve these goals, the relative abundance and species diversity of …

Comprehensive Characterization And Rna-Seq Profiling Of The Hd-Zip Transcription Factor Family In Soybean (Glycine Max) During Dehydration And Salt Stress, Vikas Belamkar, Nathan T. Weeks, Arvind K. Bharti, Andrew Farmer, Michelle A. Graham, Steven B. Cannon

Department of Agronomy and Horticulture: Faculty Publications

Background:

The homeodomain leucine zipper (HD-Zip) transcription factor family is one of the largest plant specific superfamilies, and includes genes with roles in modulation of plant growth and response to environmental stresses. Many HD-Zip genes are characterized in Arabidopsis (Arabidopsis thaliana), and members of the family are being investigated for abiotic stress responses in rice (Oryza sativa), maize (Zea mays), poplar (Populus trichocarpa) and cucumber (Cucmis sativus). Findings in these species suggest HD-Zip genes as high priority candidates for crop improvement.

Results:

In this study we have identified members of …

Control Of Herbicide-Resistant Volunteer Corn In Herbicide-Resistant Soybean, Parminder Chahal

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

Volunteer corn is a problem weed in soybean fields because it reduces yield and seed quality, and potentially harbors insects, pests, and diseases. Several pre-packaged herbicides have been registered in soybean in recent years, but response of volunteer corn to these herbicides has not yet been documented. Therefore, the first objective of this study was to evaluate the response of glufosinate-, glyphosate-, and imidazolinone-resistant volunteer corn to 20 pre-emergence (PRE) and 17 post-emergence (POST) soybean herbicides. The results indicated that PRE soybean herbicides partially controlled (< 80%) volunteer corn except clomazone, while acetyl CoA carboxylase (ACCase) inhibiting herbicides provided ≥ 85% control. Germination and emergence are critical stages in weed seed establishment and persistence. Scientific literature is not available about the factors affecting germination and emergence of volunteer corn. The second objective was to determine the effects of different environmental and agronomic factors on the germination and emergence of glyphosate-resistant hybrid and volunteer corn. The results indicated that response of hybrid and volunteer corn to majority of the variables tested was similar, suggesting that volunteer corn can germinate and emerge in a wide range of climatic conditions. Majority of growers control volunteer corn when it is visible above the soybean canopy, but this can results in early season competition with soybean. The third objective was to evaluate the impact of different densities of glyphosate-resistant volunteer corn at different control timings, and late season volunteer corn emergence on soybean yields. Late season volunteer corn emergence had no significant effect on soybean yield. Yield did not decrease with all volunteer corn densities, except with the highest density (10,000 plants and 500 clumps ha^-1) at all control timings. Soybean growers are looking for alternative herbicides, such …

Biosafety: Evaluation And Regulation Of Genetically Modified (Gm) Crops In The United States, Richard E. Goodman

Department of Food Science and Technology: Faculty Publications

This review of the safety assessment of genetically modified (GM) crops is focused primarily on the process and progress in the United States (US). It reviews the development of the safety evaluation process from the Asilomar conference in 1975 considering issues relevant to recombinant DNA technology, to discussions between the US government, academic and industrial scientists between 1984 and 1994 when the first GM crops were being field tested and evaluated commercial release for food and feed production. International guidelines were also reviewed for consistency with the US system. The overall process includes consideration of information relating to history of …

Economic Contribution Of Agriculture And Food To Arkansas' Gross Domestic Product 1997-2012, Leah English, Jennie Popp, Wayne Miller

Research Reports and Research Bulletins

Agricultural production, processing, and retail industries are major contributors to the Arkansas economy in terms of GDP. Agriculture contributes to the economy through direct agricultural production, value-added processing, and agricultural retail activities, and it also plays an important role through its interactions with other sectors. The use of non-agricultural goods and services as inputs into the agricultural sector promotes diversified growth in Arkansas’ economy; thus agriculture remains a vital part of Arkansas’ economy. This report: 1) compares the relative size of the Agriculture and Food Sector in Arkansas with those of neighboring states, the Southeastern region of the United States, …

Growing South Dakota (Fall 2014), College Of Agriculture &. Biological Sciences

Growing South Dakota (Publication of the College of Agriculture, Food and Environmental Sciences)

[Page] 2 Abundant Opportunities: Bright Ag & Bio Career Outlook Fuels Enhancements
[Page] 4 Future Focus: New Institute Supports Efforts In Science, Technology, Engineering, Math
[Page] 7 Grant Funding Updates
[Page] 8 Profiles in Leadership: Engaging Students Utilizing Problem-Based Learning
[Page] 9 Profiles in Leadership: The Value Of Experience-Based Learning
[Page] 10 Campus News
[Page] 12 Steps To Ensure Student Success: Support Fostered In Living-Learning Communities
[Page] 14 New Student Advising Model Gets High Marks
[Page] 15 Student To Student: Ag Bio Ambassadors Relish Role As Front Line Recruiters
[Page] 16 Remembering Dr. Robert Pengra: SDSU Alums Establish Tribute Scholarship …

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 …

Damping-Off, Claudia Nischwitz

All Current Publications

No abstract provided.

Systematics And Evolution Of Leandra S.Str. (Melastomataceae, Miconieae), Marcelo Reginato

Dissertations, Theses, and Capstone Projects

Phylogenetic studies in the Melastomataceae have demonstrated the need of taxonomic rearrangements in the current classification. Melastomes are among the most diverse groups of plants and several cases of known artificial taxa are observed and awaiting further resolution. One example is the Leandra s.str. clade, which includes the majority of the taxa traditionally treated in the genus Leandra. Some attempts have been made to infer the relationships of Leandra s.str., but the sampling in these earlier studies was sparse and the resolution low inside the clade. The main objective here is to propose a comprehensive phylogenetic framework for this group …

Ethnomedical, Ecological And Phytochemical Studies Of The Palauan Flora, Christopher Kitalong

Dissertations, Theses, and Capstone Projects

There has been a serious deterioration of Palauan culture, language and traditional practices over the last century. To promote health and avoid this deterioration of tradition, ecological, ethnobotanical and phytochemical studies have been carried out on the plant Phaleria nisidai Kaneh. (Thymelaeaceae), "Delal a Kar", Palauan for "Mother of Medicine". This study is the first study that sets the foundations for the development of natural Palauan therapeutics, through validation of ethnomedically significant plants. Validations of these plants is done through documenting Palauan plant ethnomedical data; mapping the distribution of Palauan plants on limestone Rock Islands; and analyzing ethnopharmacological and phytochemical …

The Effect Of A Small Ruminant Farm Operation And Sustainable Farm Practices: Soil Quality And Run-Off At The University Hickory Hill Farm, Delaware, Gulnihal Ozbay Dr., Akida J. Ferguson, Raju Khatiwada, Lathadevi K. Chintapenta

Professional Agricultural Workers Journal

This project was designed to evaluate the effect of ruminant grazing practices at Hickory Hill Farm on the surrounding environment by measuring soil nutrients and runoff chemistry. Three pastures on the farm (Goat, Cattle and Control) were selected for soil sampling and nutrient analyses were recorded. Physical water quality parameters were conducted on the runoff collected from the farm after Hurricane Sandy. The sites with animal activity had higher levels of sulfate, phosphate, nitrate, Mehlich 3 phosphorus and conductivity when compared to control site. However, the control site had slightly higher pH and chloride levels. Nitrogen and phosphorous levels were …

Economic Contribution Of The Agricultural Sector To The Arkansas Economy In 2012, Leah English, Jennie Popp, Wayne Miller

Research Reports and Research Bulletins

This report is the ninth in a series of reports examining agriculture’s economic contribution on the Arkansas economy. Utilizing data from the United States Bureau of Economic Analysis (BEA), USDA Economic Research Service (ERS), USDA National Agricultural Statistics Service (NASS), and IMPLAN Group, LLC , the economic contribution of agriculture on the Arkansas economy was estimated for the most recent year available, 2012.

The Trehalose Pathway In Maize: Conservation And Gene Regulation In Response To The Diurnal Cycle And Extended Darkness, Clémence Henry, Samuel W. Bledsoe, Allison Siekman, Alec Kollman, Brian M. Waters, Regina Feil, Mark Stitt, L. Mark Lagrimini

Department of Agronomy and Horticulture: Faculty Publications

Energy resources in plants are managed in continuously changing environments, such as changes occurring during the day/night cycle. Shading is an environmental disruption that decreases photosynthesis, compromises energy status, and impacts on crop productivity. The trehalose pathway plays a central but not well-defined role in maintaining energy balance. Here, we characterized the maize trehalose pathway genes and deciphered the impacts of the diurnal cycle and disruption of the day/night cycle on trehalose pathway gene expression and sugar metabolism. The maize genome encodes 14 trehalose-6-phosphate synthase (TPS) genes, 11 trehalose-6-phosphate phosphatase (TPP) genes, and one trehalase gene. Transcript abundance of most …

Msh1-Induced Non-Genetic Variation Provides A Source Of Phenotypic Diversity In Sorghum Bicolor, Roberto De La Rosa Santamaria, Mon-Ray Shao, Guomei Wang, David O. Nino-Liu, Hardik Kundariya, Yashitola Wamboldt, Ismail M. Dweikat, Sally Ann Mackenzie

Department of Agronomy and Horticulture: Faculty Publications

MutS Homolog 1 (MSH1) encodes a plant-specific protein that functions in mitochondria and chloroplasts. We showed previously that disruption or suppression of the MSH1 gene results in a process of developmental reprogramming that is heritable and non-genetic in subsequent generations. In Arabidopsis, this developmental reprogramming process is accompanied by striking changes in gene expression of organellar and stress response genes. This developmentally reprogrammed state, when used in crossing, results in a range of variation for plant growth potential. Here we investigate the implications of MSH1 modulation in a crop species. We found that MSH1-mediated phenotypic variation in Sorghum bicolor …

Cold Frames, High Tunnels, And Greenhouses: Choose A Growing Structure Best For You, Stacy A. Adams, Kim A. Todd

Department of Agronomy and Horticulture: Faculty Publications

Cold frames, high tunnels, and greenhouses are plant growth structures that can be used to extend the growing season or allow for use year around for growing high value specialty crops. This publication discusses the various attributes and applications of each so that plant producers in teaching, research, extension, commercially or as a hobby can determine the best structure to meet individual needs.

Cold frames, high tunnels, and greenhouses are structures that provide hobbyists and growers with options for plant protection and season extension. They vary in cost, size, structural complexity, and ability for year-round usage. The small cold frame …

Production, Marketing, And Handling Practices To Export Mcintosh Apples To Central American Markets, Mildred L. Alvarado Herrera

Doctoral Dissertations

Latin America offers a marketing opportunity for fresh produce, since many countries are entering into global integration and international trade as part of their portfolio of economic growth. However, to take full advantage of these opportunities, many questions associated with the implementation of marketing approaches, fresh produce quality retention, and profitability need be answered before undertaking this business opportunity. When it comes to developing countries such as those in Central America, and in particular - El Salvador, Honduras, and Guatemala - language, culture, technology, competitiveness, regulations, poverty, and other barriers become challenges to enter these markets successfully. In order to …

Two Spotted Spider Mite (Tetranychus Urticae) Selection To Arabidopsis Thaliana, Huzefa Ratlamwala

Electronic Thesis and Dissertation Repository

Spider mite feeding on A. thaliana induces the production of indole glucosinolates (IGs), plant secondary metabolites that negatively affect mite performance. In this study I conducted selection experiments on A. thaliana with varying levels of IGs, to determine if mites could adapt to IGs and other defense compounds. After 12 months, mites reared on host with IGs performed significantly better on A. thaliana than mites maintained on beans. However, an adaptation cost was detected between selected mite lines and their ancestral host. The qRT-PCR data on different mite lines revealed that the detoxification genes previously identified may only be involved …

Identification And Characterization Of Cysteine Protease Genes In Tobacco For Use In Recombinant Protein Production, Kishor Duwadi

Electronic Thesis and Dissertation Repository

Plants are an attractive host system for pharmaceutical protein production. Many therapeutic proteins have been produced and scaled up in plants at a low cost compared to the conventional microbial and animal based systems. The main technical challenge during this process is to produce sufficient level of proteins in plants. Low yield is generally caused by proteolytic degradation during expression and downstream processing of recombinant proteins. The yield of a human therapeutic protein interleukin (IL) -10 produced in transgenic tobacco leaves was found to be below the critical level, and is potentially due to degradation by tobacco cysteine proteases (CysPs). …

Contrasting Metabolism In Perenniating Structures Of Upland And Lowland Switchgrass Plants Late In The Growing Season, Nathan Palmer, Aaron J. Saathoff, Christian M. Tobias, Paul Twigg, Yuannan Xia, Kenneth P. Vogel, Soundararajan Madhavan, Scott E. Sattler, Gautam Sarath

Department of Agronomy and Horticulture: Faculty Publications

Background: Switchgrass (Panicum virgatum L.) is being developed as a bioenergy crop for many temperate regions of the world. One way to increase biomass yields is to move southern adapted lowland cultivars to more northern latitudes. However, many southerly adapted switchgrass germplasm can suffer significant winter kill in northerly climes.

Materials and Methods: Here, we have applied next-generation sequencing in combination with biochemical analyses to query the metabolism of crowns and rhizomes obtained from two contrasting switchgrass cultivars. Crowns and rhizomes from field-grown lowland (cv Kanlow) and upland (cv Summer) switchgrass cultivars were collected from three randomly selected post-flowering …

Growing Conditions For Algae, Angeles Mora, Tamar Melkonian, Alejandro Calderon-Urrea

STAR Program Research Presentations

With the growing demands of water in California and the increasing cost of fossil fuels to operate water-cleaning equipment, Algae was cultivated in different concentrations of Nitrogen, Phosphorus, and Potassium (NPK) during different trails to identify the best growing conditions for the removal water contaminates. Before testing algae in waste water, the Algae: Dunaliella Primolecta, Chlorella Vulgaris, and Scenedesmus Dimorphus were cultivated in four different media containing distilled water and plant vitamins. The different mediums used include: Orchid Grow More (20-20-20), Miracle Grow (30-10-10), Murashige & Skoog, and Orchid Bloom Boster (11-35-15). As a result of the investigation, the algae, …