Agronomy and Crop Sciences Commons^™

Breeding For Modified Seed Composition In Soybean: Selection Of Genotypes, Yield Stability, And Environmental Effects, Luciano Miguel Jaureguy

Graduate Theses and Dissertations

The development of cultivars with modified seed composition represents an excellent alternative to cope with the world's need for more nutritious food. Understanding the genetic and environmental factors controlling crop seed quality traits is of crucial importance for such an endeavor. The objectives of this study were: a) to evaluate the efficiency of phenotype and marker-assisted selection for low stachyose and low phytate soybean breeding lines, and their yield stability, b) to study the effect of management practices planting date and delayed harvest on soybean seed composition, and c) to study the potential association between soil properties and leaf chemical …

Evaluation Of The Recombination Efficiencies Of Flp Proteins, Linh Duy Nguyen

Graduate Theses and Dissertations

Site-specific recombination systems are powerful tools for genetic modification. They have been used to integrate a transgene into a pre-defined locus and to remove marker genes from a transgene locus. Two of the most widely used site-specific recombination systems in plants are the Cre/lox system from the bacteriophage P1 and the FLP/FRT system from the yeast Saccharomyces cerevisiae. The Cre/lox system is well-characterized and is the first choice in application of site-specific recombination system. However, some applications such as marker-free site-specific gene integration require the use of two recombination systems. In addition, the availability of alternative recombination systems can offer …

False Smut Of Rice: Histological Analysis Of Infection, Liem Thi Thanh Nguyen

Graduate Theses and Dissertations

False smut of rice, caused by Ustilaginoidea virens (Cooke) Takahashi (Teleomorph: Villosiclava virens), has become a common disease in most major rice growing regions throughout the world. Considerable confusion exists regarding the infection process and the disease cycle. Therefore, a clearer understanding of pathogenesis caused by Ustilaginoidea virens is critical for future efforts to develop genetic and chemical tools to manage false smut in Arkansas and other regions of the world. The overall goal of this research was to clarify the infection process underlying false smut, with emphasis on comparing and contrasting the histological basis of root and foliar infections. …

Documentation And Control Of Acetolactate Synthase-Resistant Barnyardgrass (Echinochloa Crus-Galli) In Arkansas Rice, Michael Joshua Wilson

Graduate Theses and Dissertations

Barnyardgrass, the most problematic grass weed of Arkansas rice, was found resistant to propanil in 1990, and since then, it has evolved resistance to quinclorac and clomazone. Barnyardgrass is now believed to have evolved resistance to acetolactate synthase (ALS)-inhibiting herbicides. The goal of this research was to confirm and determine the level of resistance of the putative resistant biotype to the ALS-inhibiting herbicides imazethapyr, bispyribac, and penoxsulam and to develop herbicide programs for controlling ALS-, propanil-, quinclorac-, and clomazone-resistant barnyardgrass. The lethal dose needed to kill 50% of the putative ALS-resistant plants was higher than that of the susceptible biotype …

Intsormil- Centa’S New Bmr Sorghum Varieties Create A Surge In Dairy Production, René Clará Valencia

INTSORMIL Scientific Publications

Scientists from the INTSORMIL-CENTA project based at the National Center for Agricultural Technology and Forestry (CENTA) of El Salvador have worked for five years to develop varieties of sorghum for grain and forage that are highly nutritious to cattle. Using the gene bmr-12, received from Dr. Gebisa Ejeta of Purdue University, they combined commercial varieties CENTA S-2, S-3 CENTA, CENTA RCV and VG 146 and were able to form new varieties containing this same gene. The first generation created 76 new varieties.

Plant Responses To Heterogeneous Salinity: Growth Of The Halophyte Atriplex Nummularia Is Determined By The Root-Weighted Mean Salinity Of The Root Zone, Nadia Bazihizina, E G. Barrett-Lennard, Timothy Colmer

Grain and Other Field Crops Research Articles

Soil salinity is generally spatially heterogeneous, but our understanding of halophyte physiology under such conditions is limited. The growth and physiology of the dicotyledonous halophyte Atriplex nummularia was evaluated in split-root experiments to test whether growth is determined by: (i) the lowest; (ii) the highest; or (iii) the mean salinity of the root zone. In two experiments, plants were grown with uniform salinities or horizontally heterogeneous salinities (10–450mM NaCl in the low-salt side and 670mM in the high-salt side, or 10mM NaCl in the low-salt side and 500–1500mM in the high-salt side). The combined data showed that growth and gas …

Variedad De Sorgo Para Grano De Ciclo Precoz Centa Liberal, Intsormil-Centa

INTSORMIL Scientific Publications

El sorgo es una alternativa para las familias agricultoras dedicadas a la producción de grano debido a la capacidad que tiene de tolerar sequías prolongadas.

Sus características lo vuelven una alternativa, incluso para sustituir al maíz, aún con las limitantes hídricas que se han incrementado en los últimos años debido a los efectos del cambio climático.

Es un cultivo rústico capaz de producir en condiciones adversas de suelo (excepto suelos mal drenados), clima y de poco manejo agronómico; se adapta desde los 10 hasta los 1000 m.s.n.m.

La variedad CENTA Liberal que hoy se pone a disposición de los productores …

Centa S-3 Bmr Y Centa S-4 Bmr: Variedades De Sorgo Forrajero Para Ensilaje, Intsormil-Centa

INTSORMIL Scientific Publications

Siendo la nutrición animal un factor importante para el éxito de la ganadería de leche y carne en El Salvador, el Centro Nacional de Tecnología Agropecuaria y Forestal “Enrique Álvarez Córdova” (CENTA), en colaboración con el Instituto de Sorgo, Mijo y Otros Granos (INTSORMIL), ha desarrollado dos nuevas variedades de sorgo para ensilaje con alta digestibilidad, capaces de incrementar la producción de leche y carne en el ganado bovino con el objetivo de fortalecer la seguridad alimentaria en el país.

La utilización del sorgo en forma de ensilaje se ha incrementado en nuestro país a partir de los años 80, …

Economic Contribution Of The Agricultural Sector To The Arkansas Economy In 2010, Katherine Mcgraw, Jennie Popp, Wayne Miller

AAES Research Reports and Research Bulletins

This report is the seventh 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 Minnesota IMPLAN Group, Inc. (MIG), the economic contribution of agriculture on the Arkansas economy was estimated for the most recent year available, 2010. Gross Domestic Product (GDP) by State information for Arkansas in 2010 was compared with those of other states in the Southeast U.S. to give a measure of the relative importance of agriculture in Arkansas.2 The total …

Marketing Contracts, Overconfidence, And Timing In The Canadian Wheat Market, Fabio L. Mattos, Stefanie A. Fryza

Department of Agronomy and Horticulture: Faculty Publications

This paper investigates factors that impact marketing performance in the Canadian wheat market. Using data provided by the Canadian Wheat Board (CWB) for six crop years, results indicate that producers were not able to profitably use all marketing contracts offered by the CWB, earlier pricing tended to generate better performance, there was a negative relationship between activeness and performance (suggesting overconfidence in marketing skills), and performance was generally worse in volatile crop years. Further analysis reveals some of these findings differ when outperforming and underperforming producers are investigated separately, particularly with respect to activeness and volatility.

Arkansas Corn And Grain Sorghum Performance Tests 2012, R. D. Bond, D. G. Dombek, J. A. Still, R. M. Pryor

Arkansas Agricultural Experiment Station Research Series

Corn and grain sorghum performance tests are conducted each year in Arkansas by the University of Arkansas System Division of Agriculture. The tests provide information to companies marketing seed within the state and aid the Arkansas Cooperative Extension Service in formulating recommendations for producers.

Summaries Of Arkansas Cotton Research 2011, Derrick M. Oosterhuis

Arkansas Agricultural Experiment Station Research Series

No abstract provided.

Survey Of Endosymbionts In The Diaphorina Citri Metagenome And Assembly Of A Wolbachia Wdi Draft Genome, Surya Saha, Wayne B. Hunter, Justin Reese, J. Kent Morgan, Mizuri Marutani-Hert, Hong Huang, Magdalen Lindeberg

School of Information Faculty Publications

Diaphorina citri (Hemiptera: Psyllidae), the Asian citrus psyllid, is the insect vector of Ca. Liberibacter asiaticus, the causal agent of citrus greening disease. Sequencing of the D. citrimetagenome has been initiated to gain better understanding of the biology of this organism and the potential roles of its bacterial endosymbionts. To corroborate candidate endosymbionts previously identified by rDNA amplification, raw reads from the D. citri metagenome sequence were mapped to reference genome sequences. Results of the read mapping provided the most support for Wolbachia and an enteric bacterium most similar to Salmonella. Wolbachia-derived reads were extracted using …

Amelioration Of Root Disease Of Subterranean Clover (Trifolium Subterraneum) By Mineral Nutrients, Tim Scanlon, Tiernan A. O’Rourke, Megan H. Ryan, Martin J. Barbetti, Krishnapillai Sivasithamparam

Journal articles

Subterranean clover (Trifolium subterraneum) is a key pasture legume across southern Australia and elsewhere. Decline in subterranean clover pastures was first recognised in Australia during the 1960s and manifests as an increase in weeds and a decrease in desirable legume species. While both root disease and poor nutrition contribute to subterranean clover pasture decline, the relationships between root disease and nutrition have not been determined. The objective of this study was to define these relationships. Field experiments were undertaken to determine the nutritional and pathogen status of soils and subterranean clover from three Western Australian field sites. Subsequently, …

Innovative Approach To Active Learning, John G. Graveel, George E. Van Scoyoc

IMPACT Presentations

Presentation on a course redesign and project plan given at the American Society of Agronomy Annual Meeting, Cincinnati, OH.

Asareca-Intsormil: Regional Sorghum Research And Development Workshop, September 2–6, 2012, Executive Hotel, Adama, Ethiopia, Kimberly Christiansen

INTSORMIL Scientific Publications

Priorities in Sorghum Research and Development Cross-Cutting Elements

All priorities should be cognizant and address:

Gender responsiveness

User friendliness in sharing knowledge and information

Sustainable growth

Capacity building

Collaboration with public and private partners especially NARS, and regional and international organizations

Production

Integrated soil and water management in response to climate change

Integrated pest management

Cropping systems

Mechanization to alleviate drudgery

Breeding/Genetics

Breeding high yielding sorghum cultivars with enhanced ecological adaptation (drought tolerance and Striga resistance and diseases and pests) and superior grain quality

Development, release and distribution of enhanced sorghum germplasm materials with desired end-use quality attributes (malt, biofuel, …

2013 Barley Variety Sowing Guide For Western Australia, Blakely Paynter, Andrea Hills, Harmohinder Dhammu, Sanjiv Gupta

Bulletins 4000 -

This publication presents general information on market demand by industry sector, variety and Port Zone for each of the malting barley varieties that will potentially be segregated in Western Australia at the 2013/14 harvest (Tables 1, 2 and 3).

This information is presented on behalf of the Grain Industry of Western Australia (GIWA) Barley Council. It represents the expected demand from domestic and international customers of Western Australian barley. Before planting any variety with a malting or food classification growers are advised to talk to their preferred grain acquirer to determine their demand for each malt and food variety, potential …

Studies Of Drought Tolerance Of Hard Red Winter Wheat (Triticum Aestivum L.) Cultivars In Nebraska, Sumardi Bin Abdul Hamid

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

In Nebraska, about 75% of the wheat production is in the western half of the state, and about 92% of the winter wheat acreage is in dryland production, where productivity is limited by low and/or uncertain rainfall. We have investigated the effects of water stress on few established winter wheat (Triticum aestivumL.) cultivars, which are known for their superior adaptation to either rainfed or irrigated wheat production systems in western Nebraska. We also began a study to investigate the variation in the root system architecture to confer drought tolerance in winter wheat. The objectives of this study were …

Arkansas Wheat Cultivar Performance Tests 2011-2012, R. E. Mason, R. G. Miller, J. P. Kelley, E. A. Milus

Arkansas Agricultural Experiment Station Research Series

Wheat cultivar performance tests are conducted each year in Arkansas by the Arkansas Agricultural Experiment Station, Department of Crop, Soil and Environmental Sciences. The tests provide information to companies developing cultivars and/or marketing seed within the state and aid the Arkansas Cooperative Extension Service in formulating cultivar recommendations for small-grain producers.

Effects Of Meloidogyne Incognita, Soil Physical Parameters, And Thielaviopsis Basicola On Cotton Root Architecture And Plant Growth, Jianbing Ma

Graduate Theses and Dissertations

The root-knot nematode, Meloidogyne incognita, and the seedling pathogen, Thielaviopsis basicola, commonly co-exist in Arkansas cotton fields and may interact resulting in increased losses. The primary objective of this research was to evaluate the effects of soil physical parameters on these soilborne pathogens and cotton growth in controlled environmental, field, and microplot studies. Controlled environmental experiments used two soil bulk densities and four pathogen treatments: non-infested soil, soil infested with M. incognita or T. basicola and soil infested with both pathogens. The results indicated bulk density generally did not affect seedling growth or disease since soils had low penetration resistance …

The Evolution Of Natural Plant Communities Through Crop Migration And Crop-To-Weed Gene Flow, Meredith G. Schafer

Graduate Theses and Dissertations

With the rising demand for food and biofuels, the efficiency of crop production has become vital to assuring food security. Genetically engineered (GE) crop varieties are broadly thought to be a solution for improving the efficiency of crop production, but concerns regarding their release have heightened as more discoveries have focused on the influence of genetically engineered crops on native and weedy plant species. Risk assessment of GE crop varieties focuses on two main areas: feralization of crop systems and crop-weed hybridization. Risks include naturalization, transgene introgression, and the formation of novel genotypes in natural systems. In this study, roadside …

The Identification Of Quantitative Trait Loci For Sucrose And Stachyose Content In Soybean Seed, Ailan Zeng

Graduate Theses and Dissertations

Sucrose is a desirable sugar in soybean seed that affects the quality and taste of soyfoods, while stachyose is a non-digestible sugar that induces flatulence in non-ruminant animals. Therefore, soybean cultivars with high sucrose and/or low stachyose would be valuable for soyfood and meal markets. The objectives of this study were to identify quantitative trait loci (QTL) or genes associated with seed sucrose and stachyose content using simple sequence repeat (SSR) or single nucleotide polymorphism (SNP) markers. A low sucrose line, MFS-553, was crossed with a high sucrose plant introduction, PI 243545, to develop the sucrose QTL mapping population. A …

Economic Implications Of Extreme Heat Effects On Rice Yield And Milling Quality In Arkansas, Nate Lyman

Graduate Theses and Dissertations

Future increases in global surface temperature threaten those worldwide who depend on rice production for their livelihoods and food security. Past analyses of extreme heat effects on rice production have focused on paddy yield and have not accounted for the detrimental impact of extreme heat on milling quality outcomes which ultimately determine edible (marketable) rice yield and value. Using rice yield and milling quality data on six popular rice cultivars from Arkansas, USA, combined with on-site, half-hourly and daily temperature observations, this study finds a nonlinear effect of extreme heat exposure on yield and milling quality. A 1 °C increase …

Is Local Food In Your Future?: An Analysis Of The Viability Of The Local Food Movement, Jennifer A. Sliney

Pell Scholars and Senior Theses

The Local Food Movement has arisen in recent decades as a proposed solution to problems in the current food distribution system. Proponents of the movement look to solve problems such as unsustainable farming practices, greenhouse gas emissions, and unhealthy communities. Skeptics raise questions as to whether local food is truly capable of accomplishing any of those. The author proposes that as a solution, aspects of the Local Food Movement such as urban agriculture and attempts at community development should be taken more seriously in order to create a better future for the land and people alike.

Soybean Maturity Group Tradeoffs: Irrigation, Weed Control, And Nitrogen Fixation, Ryan Wegerer

Graduate Theses and Dissertations

This thesis is divided into four chapters. Chapter I introduces the rationale behind the study and gives a brief overview of the overall study covering weed control, irrigation needs and nitrogen fixation amounts across soybean maturity group. Chapter II will go into further detail outlining the first applied experiment dealing with weed control and irrigation issues. Alternative weed control methods are analyzed in conjunction with irrigation risk analysis across soybean maturity group in response to agricultural issues of glyphosate resistance and declining ground water supply in the Arkansas delta region. Chapter III will jointly examine irrigation application amounts and nitrogen …

Evaluation Of Isothiocyanates And Herbicide Programs As Methyl Bromide Alternatives For Weed Control In Polyethylene-Mulched Tomato And Bell Pepper, Pratap Devkota

Graduate Theses and Dissertations

Methyl bromide (MeBr), a Class I ozone –depleting substance, has been banned for ordinary agricultural uses. In the absence of an effective MeBr alternative, weed control is a major challenge for commercial tomato and bell pepper production. Field trials were conducted at Fayetteville, AR, to compare allyl isothiocyanate (ITC), metam sodium, and herbicide programs with the standard MeBr application (mixture of MeBr plus chloropicrin at 67% plus 33%, respectively, hereafter referred to as MeBr) for crop injury, weed control, viable yellow nutsedge tubers, and marketable yield in low–density polyethylene (LDPE) mulched tomato and bell pepper production. In addition, herbicide programs …

B.R. Wells Rice Research Studies 2011, R. J. Norman, K.A. K. Moldenhauer

Arkansas Agricultural Experiment Station Research Series

No abstract provided.

The Impact Of Selected Forage Legumes On Cattle Performance, Forage Production, And Soil Quality, And Evaluation Of Legume Persistence Under Grazing, Bradley Edward Briggs

Graduate Theses and Dissertations

Interest in substituting legumes for N fertilizer in beef cattle grazing systems has recently increased with rising fertilizer prices. Legumes are well known for their ability to fix atmospheric N and decrease dependence on input of N fertilizer. However, there are still difficulties associated with legume utilization including establishment and persistence. Two experiments were conducted to evaluate legume performance under herbivory. The objective of Experiment 1 was to compare forage production and beef cattle gains from annual ryegrass [Lolium multiflorum (L.)] and bermudagrass [Cynodon dactylon (L.) Pers.] pastures fertilized with N or overseeded with legumes. Gelbvieh × Angus …

The Potential Environmental Benefits Of Hybrid Rice Varieties, Haxhire Myrteza

Graduate Theses and Dissertations

With water insufficiency being already a major issue and potential carbon policies on greenhouse gas (GHG) emissions, Arkansas rice producers may need to undergo some changes in regards to rice cultivar selection. The purpose of this study is to estimate the environmental benefits of cultivating hybrid rice varieties as opposed to conventional and Clearfield rice varieties. To accomplish this goal, water use and GHG emissions were estimated on per acre (ac) and per bushel (bu) basis for most commonly cultivated rice varieties in Arkansas. The study focuses particularly on six main rice stations in the State of Arkansas. The hypothesis …

Intensive Production Of Millet And Sorghum For Evolving Markets In The Sahel, John H. Sanders, Botorou Ouendeba

INTSORMIL Scientific Publications

One principal constraint to improving the performance of millet and sorghum systems is overcoming the conventional wisdom. The conventional wisdom has some or all of these characteristics depending upon where you hear it. “Sorghum and millet are subsistence crops.” “They do not respond to fertilization.” “Even if they do respond to fertilizer, it is not profitable.” “Farmers will not use fertilization on these crops even if there were agronomic and economic responses.” “Banks will not lend to farmers for sorghum and millet fertilization.”