Agricultural Science Commons^™

Efficacy And Costs Of Controlling Eastern Redcedar, John Ortmann, James L. Stubbendieck, Robert A. Masters, George H. Pfeiffer, Thomas B. Bragg

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

(Juniperus virginiana L.) is reducing grassland productivity across much of the Great Plains. Control methods include broadcast prescribed fire, herbicides, cutting, and individual tree ignition. All methods have disadvantages when used alone. Fire can be ineffective against larger trees. Intensive methods can be too expensive for low-productivity grasslands. The objectives of this research were to determine the effects of broadcast prescribed fie alone as measured at 3 weeks after fire; to compare the effects of picloram herbicide application with or without fire, sawing with or without fire, and individual tree ignition with fire; and to compare all treatment costs. …

Productivity Of Well-Watered Panicum Virgatum Does Not Increase With Co2 Enrichment, Philip A. Fay, H. Wayne Polley, Virginia L. Jin, Michael J. Aspinwall

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Aims Rising atmospheric CO₂ has been shown to increase aboveground net primary productivity (ANPP) in water-limited perennial grasslands, in part by reducing stomatal conductance and transpiration, thereby reducing depletion of soil moisture. However, the benefits of CO₂ enrichment for ANPP will vary with soil type and may be reduced if water limitation is low. Little is known about CO₂ effects on ANPP of Panicum virgatum, a perennial C₄ tallgrass and potential bioenergy crop. We hypothesized that if water limitation is minimized, (i) CO₂ enrichmentwould not increase P. virgatum ANPP because photosynthetic rates of this C …

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 Environment And Genotype On Charcoal Rot Development On Soybeans, Micah Diane Doubledee

Graduate Theses and Dissertations

Charcoal rot of soybean, caused by the soilborne fungus Macrophomina phaseolina (Tassi) Goid, is a disease associated with high soil temperature and low soil moisture. Above-ground symptoms, which can be difficult to distinguish from drought symptoms, include low vigor, dead leaves that remain attached to the plant, early senescence and yield loss. Irrigation limits damage, but does not prevent colonization of the tissue by the pathogen. No soybean line is immune to M. phaseolina, but a few lines may have moderate resistance. The objectives of this research were to 1) determine the effects of genotype and drought on the development …

Market Analysis Of Fresh Berries In The United States, Kristina Sobekova

Graduate Theses and Dissertations

This thesis contains a market analysis of fresh berries in United States. Specifically, it addresses strawberry, blueberry, blackberry and raspberry markets during 2008-2011. A double log model and the Almost Ideal Demand model are used to gain insight into the demand side of the market. An equilibrium displacement model is used to develop suggestions for producers and decision makers. The results demonstrate that retail demand for berry crops is elastic and that the different berries are substitutes for one another. The equilibrium displacement model is used to predict producer surplus changes to industry wide efforts aimed at both production efficiencies …

High-Throughput Transcriptome Sequencing For Snp And Gene Discovery In A Moth, Nicholas J. Miller, Jing Sun, Thomas W. Sappington

Department of Entomology: Faculty Publications

The western bean cutworm, Striacosta albicosta (Smith) (Leptidoptera: Noctuidae) is a pest of corn (Zea mays L.) and dry beans that underwent a dramatic range expansion in North America during the first decade of the 21st century. Research into the population genetics of this species has been hindered by a lack of genetic markers. The transcriptome of adult male S. albicosta was partially sequenced using Illumina sequencing-by-synthesis. Assembly of the sequence reads yielded 16,847 transcript sequences, of which 6,631 could be assigned a putative function. A search for single nucleotide polymorphisms (SNPs) identified 2,487 candidate SNPs distributed among 1,265 …

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.

Genetic Structure And Mating System Of Wild Cowpea Populations In West Africa, Eric B. Kouam, Remy S. Pasquet, Pascal Campagne, Jean Baptiste Tignegre, Kevin Thoen, Remi Gaudin, Jeremy T. Ouedraogo, Abdulai B. Salifu, Geoffrey M. Muluvi, Paul Gepts

All Peer-Reviewed Publications

Background: Cowpea is a highly inbred crop. It is part of a crop-weed complex, whose origin and dynamics is unknown, which is distributed across the African continent. This study examined outcrossing rates and genetic structures in 35 wild cowpea (Vigna unguiculata ssp. unguiculata var. spontanea) populations from West Africa, using 21 isozyme loci, 9 of them showing polymorphism.Results: Outcrossing rates ranged from 1% to 9.5% (mean 3.4%), which classifies the wild cowpea breeding system as primarily selfing, though rare outcrossing events were detected in each population studied. Furthermore, the analyses of both the genetic structure of populations and the relationships …

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 …

Identification Of Root-Knot Nematode Species Occurring On Tomatoes In Kenya: Use Of Isozyme Phenotypes And Pcr-Rflp, Rael Birithia, Wanjohi Waceke, Peter Lomo, Daniel Masiga

All Peer-Reviewed Publications

Root-knot nematodes (RKN) are serious pests of tomato production in Kenya. Accurate identification of the plant parasitic nematodes is important for their effective management. A study conducted to assess their prevalence and identify RKN occurring on tomatoes in Central Kenya showed infestation of the crop in all the three districts. Of the total sampled plants (N = 900), the RKN infestation level ranged from 28 to 62%. RKN disease severity ranged from 2.5 to 5.3 in all the locations. Meloidogyne incognita, M. javanica and M. arenaria were the only species found infesting tomatoes in these areas. Female nematodes sampled from …

Chlorophyll-Based Approach For Remote Estimation Of Crop Gross Primary Production: From In Situ Measurements To Satellite Imagery, Yi Peng

School of Natural Resources: Dissertations, Theses, and Student Research

The synoptic and accurate quantification of crop gross primary production (GPP) is essential for studying carbon budgets in croplands and monitoring crop status. The objective of this dissertation is to develop a quantitative technique to estimate crop GPP using remotely sensed data collected from close range to satellite altitudes. In this study, a model based on a recently developed paradigm, which relates crop GPP to a product of total crop chlorophyll content and incident radiation affecting vegetation photosynthesis, was justified for the remote estimation of GPP in crops. The model was tested with ground-observed incoming photosynthetically active radiation (PAR_{in …}

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 …

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 …

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.

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 …

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 …

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 …

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 …

Use Of Cti Grinders For Sorghum Flour Production And Utilization: Final Report, Vilma Ruth Calderón De Zacatares, Lily Marisol López, Kris Emillee Duville, Carla Elizabeth Bermúdez

INTSORMIL Scientific Publications

The use of sorghum for human consumption to add value to the crop and increase its profitability, especially for small and medium producers, has contributed to food security and nutrition in El Salvador. CENTA is promoting the cultivation of sorghum as an alternative to food production in rural and urban areas. Since 2010 when wheat prices lower again, sorghum was no more an alternative to replace wheat in certain types of food, but is being used in more stable markets, as people allergic to gluten, people with diabetes and to correct nutritional deficiencies such as iron deficiency anemia because of …