Agronomy and Crop Sciences Commons^™

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 …

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

Arkansas Agricultural Experiment Station Research Series

No abstract provided.

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 …

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.”

Feed The Future Releases Two New Sorghum Varieties In Nicaragua, Kimberly Christiansen

INTSORMIL Impacts and Bulletins

de Tecnologia Agropecuaria (INTA), the Collaborative Research Support Program for Sorghum, Millet and Other Grains (INTSORMIL) has released two new varieties of sorghum in Nicaragua that will be used for forage (plant material eaten by grazing livestock).

These new varieties exhibit the “brown midrib” trait (bmr), which has been used for many years by sorghum producers in the United States. The bmr trait increases the digestibility of sorghum by reducing the amount of lignin, a chemical compound found in the cell walls of plants. The more digestible sorghum is for the livestock that consume it, the higher the quality of …

Effects Of Thiamethoxam Seed Treatments On Bean Leaf Beetles, Chelsea L. Piitz

Department of Entomology: Dissertations, Theses, and Student Research

The increased use of thiamethoxam seed treatments for controlling target pests such as the bean leaf beetle, Cerotoma trifurcata (Forster), suggests the need for methods to measure and monitor the development of resistance to these insecticides. Overwintering and F1 bean leaf beetles were collected from alfalfa and soybean fields and used in early growth stage soybean studies to measure toxicity of thiamethoxam both in greenhouse experiments and laboratory bioassays involving exposure to treated foliage. Lethal and sub-lethal effects were detected in both greenhouse and lab bioassays. Lethal concentrations determined from laboratory assays were compared with residues determined from field grown …

Susceptibility Of The Fall Armyworm, Spodoptera Frugiperda (Lepidoptera: Noctuidae), At Santa Isabel, Puerto Rico, To Different Insecticides, Difabachew K. Belay, Randy M. Huckaba, John E. Foster

Department of Entomology: Faculty Publications

The fall armyworm (FAW), Spodoptera frugiperda (J. E. Smith), is a polyphagous migratory pest, which is endemic to the Western Hemisphere and attacks more than 80 plant species including maize, sorghum, cotton, rice, millet, peanut, alfalfa, and other cultivated and wild plant species. Presence of multiple generations and the ability to migrate and feed on a wide range of host plants makes FAW one of the most severe economic pests throughout the Western Hemisphere. In corn, yield losses due to FAW damage can reach up to 32% in the United States and 45–60% in Nicaragua. Insecticides are used as major …

Composting Manure And Other Organic Materials, Charles S. Wortmann, Charles A. Shapiro

Department of Agronomy and Horticulture: Faculty Publications

The Composting Process

Composting is the aerobic decomposition of manure or other organic materials in the thermophilic temperature range (104-149oF). Composted material is odorless, fine-textured, and low-moisture. It can be bagged and sold for use in gardens or nurseries, or used as fertilizer on cropland with little odor or fly breeding potential. Composting improves the handling characteristics of any organic residue by reducing its volume and weight. Composting can kill pathogens and weed seeds.

Disadvantages of composting organic residues include loss of nitrogen and other nutrients, time for processing, cost for handling equipment, available land for composting, odors, marketing, diversion …

Crop Management Technologies Approved/Recommended To Farmers By Intsormil Supported Nars Programs 2006-2012, Elvis A. Heinrichs

INTSORMIL Scientific Publications

Table listing year, crop (sorghum or pearl millet), country, technology approved/ recommended for release to farmers (sowing rate, spacing, fertilizer, pesticide, herbicide, tied ridges etc.), and comments regarding crop management technologies approved/recommended to farmers by INTSORMIL-supported NARS programs, 2006-2012. Countries included are: Burkina Faso, Ethiopia, Ghana, Mali, Mozambique, Niger, Uganda, Zambia, El Salvador, and Nicaragua.

Escape From Preferential Retention Following Repeated Whole Genome Duplications In Plants, James C. Schnable, Xiaowu Wang, J. Chris Pires, Michael Freeling

Department of Agronomy and Horticulture: Faculty Publications

The well supported gene dosage hypothesis predicts that genes encoding proteins engaged in dose–sensitive interactions cannot be reduced back to single copies once all interacting partners are simultaneously duplicated in a whole genome duplication. The genomes of extant flowering plants are the result of many sequential rounds of whole genome duplication, yet the fraction of genomes devoted to encoding complex molecular machines does not increase as fast as expected through multiple rounds of whole genome duplications. Using parallel interspecies genomic comparisons in the grasses and crucifers, we demonstrate that genes retained as duplicates following a whole genome duplication have only …

Returns To The Introduction Of New Sorghum Cultivars Into The Dairy Industry Of El Salvador, Alexis Homero Villacís Aveiga

INTSORMIL Scientific Publications

The returns to the introduction of new photo-insensitive sorghum varieties into the dairy industry were analyzed to determine changes in the welfare of consumers, processors, producers and the society. The economic surplus method was used along with a survey data of a stratified sample of 150 farms conducted in 2011 in El Salvador. Results indicate that there are large returns per dollar spent and substantial benefits to consumers, processors and producers. Results also show that the adoption of these new technologies represents advantages in production costs of milk in each farm size. These cost savings per bottle are very small …

Establishment Method And Cultural Practice Effects On Sports Turf, Josh Anderson

Graduate Theses and Dissertations

The use of soil-based sod on sand-based rootzones for the establishment of sports fields and golf courses is a common occurrence. Furthermore, the use of soil-based sod on sand-based rootzones can lead to potential problems associated with decreased water infiltration, gas exchange, rooting, and turfgrass quality caused by soil layering. Core-aerification and sand topdressing may help alleviate the problems associated with soil layering from the use of soil-based sod on sand-based rootzones. Therefore, the objectives of this research were to evaluate the effects of sod establishment methods and post- establishment cultural practices on the infiltration rate, moisture content, divot resistance, …

The Evolution Of Rural Farming In The Scottish Highlands And The Arkansas Delta: Investments And Inequalities, Madalyn Watkins

Crop, Soil and Environmental Sciences Undergraduate Honors Theses

The development and evolution of an agricultural system is influenced by many factors including binding constraints (limiting factors), choice of investments, and historic presence of land and income inequality. This study analyzed the development of two farming systems: mechanized, “economies of scale” farming in the Arkansas Delta and crofting in the Scottish Highlands. The study hypothesized that the current farm size in each region can be partially attributed to the binding constraints of either land or labor. In Scotland, it was found that the continuous binding constraint was the availability of arable land. In Arkansas, the binding constraint began as …

Identification And Confirmation Of Ssr Markers And Qtl For Seed Calcium Content And Hardness Of Soybean, Moldir Orazaly

Graduate Theses and Dissertations

The health benefits and the nutritional values of soyfood products have expanded the demand for food-grade soybean varieties. For whole soyfood products such as natto, small seeded varieties with proper texture are essential. Seed calcium content and hardness are main factors in determining the seed texture. Utilizing molecular markers associated with quantitative trait loci (QTL) for marker assisted selection (MAS) has been an efficient technique for breeders. To find molecular markers associated with a trait is an initial step. The confirmation of QTL in different environments and in different genetic backgrounds is important for MAS. The objectives of this research …

Modifying The Fatty Acid Profile Of Soybean Oil For Nutritional And Industrial Applications, Hyunwoo Park

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

The objectives of this study are: 1. To develop of soybean oil low in palmitic acid and elevated in stearic and oleic acids for margarine source. 2. To produce the high omega-3 fatty acid and astaxanthin in soybean seed as a feedstock for aquaculture. Over expression of mangosteen stearoyl-ACP thioesterase gene increased stearic acid content up to 10% to 15%. The identified elevated stearic acid events were crossed with our high oleic acid/low palmitic acid event. Average stearic and oleic acid content ranged 14 to 19% and 68 to 73% respectively. Stearic acid content of elevated stearic acid soybean event …

Determining Compost Carryover For Optimal Use In An Organic Corn Squash Rotation, Davey J.R. Olsen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In 2008–2011 a graduate project was undertaken by Davey Olsen under the supervision of Utah State University (USU) Plant, Soils and Climate professors, Drs. Jennifer Reeve, Dan Drost, and Astrid Jacobson. The project investigated a new way of measuring the benefits of applying compost to organically certified horticultural crops. In particular, the carryover of these benefits in the three years following a one-time application was studied. A field trial at the USU Organic Farm modeled the carryover of nitrogen and phosphorus in a corn and squash rotation, while laboratory analysis investigated aspects of nitrogen availability and compost decomposition over time. …

Weed Science Research Summaries 2011, K. L. Smith, J. A. Bullington, R. C. Doherty, J. R. Meier

Arkansas Agricultural Experiment Station Research Series

No abstract provided.

Ecology And Integrated Pest Management Of Western Bean Cutworm Striacosta Albicosta (Smith) (Lepidoptera: Noctuidae) In Field Corn, Silvana L. Vieira De Paula Moraes

Department of Entomology: Dissertations, Theses, and Student Research

Western bean cutworm, Striacosta albicosta (Smith) (Lepidoptera: Noctuidae), is a native pest of dry beans (Phaseolus vulgaris L.) and corn (Zea mays L.), and historically distributed in the western United States. The insect’s recent expansion eastward is documented since 1999. The species is univoltine, the adults typically emerge in the middle of July, lay eggs on corn leaves, and the larvae feed on different corn tissues. In the fourth instar, larvae start colonization of the ear where they feed on kernels. There is a narrow window for management and early detection of the pest in the field is …

Insecticidal Control Of Bemisia Tabaci (Hemiptera: Aleyrodidae) Transmitting Carlavirus On Soybeans And Detection Of The Virus In Alternate Hosts, Difabachew K. Belay, Randy M. Huckaba, Axel M. Ramirez, Jose C. V. Rodrigues, John E. Foster

Department of Entomology: Faculty Publications

A Carlavirus transmitted by Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is an important disease of soybean nurseries in Puerto Rico causing substantial germplasm losses. Insecticide bioassay experiments were conducted at Dow AgroSciences (DAS) Research Station, Santa Isabel, Puerto Rico, either by spraying insecticides on B. tabaci infested soybean leaves or introducing B. tabaci adults onto insecticide-sprayed soybean leaves. Moreover, host plants were surveyed to detect the virus in overwintering hosts that serve as a source of inoculums. The direct spray experiment showed that Nuprid 2F (Imidacloprid), Capture 2 EC (Bifenthrin), Thionex (Endosulfan), Lannate LV (Methomyl), and Dimethoate gave good level ( …

Cotton Response To High Temperature Stress During Reproductive Development, Justin B. Phillips

Graduate Theses and Dissertations

Temperature is a primary controller of the rate of plant growth, developmental events, and fruit maturation. Increased temperatures from global climate change are projected to cause substantial losses in crop productivity by the end of the twenty-first century. Elevated temperatures affect all stages of cotton development, but the crop seems to be particularly sensitive to adverse temperatures during reproductive development. In Arkansas, temperature stress is considered to be one of the main factors affecting cotton yield. Environmental stress during floral development is a major reason for the disparity between actual and potential yields. Field and growth chamber studies were conducted …

Multifunctionality In U.S. Rice Production: A Logit Analysis In Farmers Participation, Juan Tur Cardona

Graduate Theses and Dissertations

Multifunctional agriculture is particularly fundamental to some working lands conservation policies and programs, such as the Environmental Quality Incentive Program (EQIP), Conservation Security Program (CSP) and Wildlife Habitat Incentive Program (WHIP). Farmers can also be engaged in providing recreational and agri-tourism services such as hunting, fishing, bird-watching, farm tours, petting zoos and hospitality services. Using the Agricultural Resource Management Survey (ARMS) we analyze factors associated with participation in conservation, recreation and agri-tourism activities as a function of farm structure, farm financial measures, production practices, and socio-demographic characteristics of the farm operator. To estimate the functional relationships we estimate a binary …

Effect Of Water-Deficit Stress On Cotton During Reproductive Development, Dimitra Loka

Graduate Theses and Dissertations

Water deficit is a major abiotic factor limiting plant growth and crop productivity around the world. Cotton (Gossypium hirsutum L.) is considered to be relatively tolerant to drought and the effects of water stress on leaf physiology and metabolism have been extensively documented. However, information is lacking on the effect of water-deficit stress on the cotton flower. It was hypothesized that water-deficit stress would impair gas exchange functions which consequently would result in perturbation of carbohydrates of cotton reproductive units. To investigate this hypothesis growth room studies and field studies were conducted with the objectives being to document the physiological …

Herbicide Resistance Mechanism(S) In Italian Ryegrass (Lolium Perenne Ssp. Multiflorum) Populations In The Southern United States, Reiofeli Algodon Salas

Graduate Theses and Dissertations

Italian ryegrass is a principal weed problem in wheat production fields in the Southern US. Resistance to herbicides diclofop, mesosulfuron, and pinoxaden among ryegrass populations has been reported. Glyphosate-resistant Italian ryegrass populations were identified in Desha County, Arkansas. This research aimed to 1) determine resistance patterns to ACCase (diclofop and pinoxaden) and ALS (imazamox, mesosulfuron, and pyroxsulam) herbicides among Italian ryegrass populations from the southern US; 2) determine if cytochrome P450-mediated enhanced herbicide metabolism contributed to resistance; and 3) elucidate the resistance mechanism to glyphosate in four Arkansas populations (Des03, Des05, Des14, and D8). For objective 1, 30 accessions from …

Uso De Molinos Cti Para La Producción Y Uso De Harina De Sorgo, Lily Lopez, Kris Duville, Carla Bermudez, Vilma Ruth Calderón, Lloyd Rooney

INTSORMIL Presentations

El aprovechamiento del sorgo para la alimentación humana permite agregar valor al cultivo y aumentar su rentabilidad, especialmente para pequeños y medianos productores, contribuyendo a la seguridad alimentaria y nutricional del país.

CENTA esta promoviendo el cultivo del sorgo como una alternativa para la produccion de alimentos en las areas rurales.

Desde 2010 cuando el trigo bajo de precio nuevamente, dejo de ser una alternativa para la sustitucion del trigo, pero se le han buscado mercados mas estables, personas alergicas al gluten, personas diabéticas, y productos nutritivos para corregir deficiencias nutricionales como la anemia por falta de hierro, productos artesanales …