Agriculture Commons^™

Nutrient Partitioning And Grain Yield Of Tanam-Rnai Wheat Under Abiotic Stress, Mary J. Guttieri, Ricardo J. Stein, Brian M. Waters

Department of Agronomy and Horticulture: Faculty Publications

Aims — Decreased expression of TaNAM genes by RNAi results in delayed senescence and decreased grain protein, iron, and zinc concentrations. Here, we determined whether NAM expression level alters onset of senescence under stress conditions, whether delayed senescence in the TaNAM-RNAi line resulted in improved tolerance to post-anthesis abiotic stress, and determined the effects of post-anthesis abiotic stress on N and mineral remobilization and partitioning to grain.

Methods — Greenhouse-grown WT and TaNAM-RNAi wheat were characterized in two studies: three levels of N fertility or water limitation during grain fill. Studies were conducted under both optimal and heat stress …

Seroprevalence Of Brucellosis In Livestock Within Three Endemic Regions Of The Country Of Georgia, Eliso Mamisashvili, Ian T. Kracalik, Tinatin Onashvili, Lela Kerdzevadze, Ketevan Goginashvili, Tamar Tigilauri, Marina Donduashvili, Marina Nikolaishvili, Irma Beradze, Marina Zakareishvili, Maka Kokhreidze, Makvala Gelashvili, Nino Vepkhvadze, S. Elizabeth Rácz, Philip H. Elzer, Mikeljon P. Nikolich, Jason K. Blackburn

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Brucellosis is the one of most common livestock zoonoses in Georgia, resulting in significant economic losses. Livestock were sampled in three regions of Georgia (Kakheti, Kvemo Kartli, Imereti). Districts that historically reported high numbers of brucellosis related morbidity were selected for serological, bacteriological and molecular surveys. Surveying efforts yielded samples from 10,819 large and small ruminants. In total, 735 serological tests were positive on Rose Bengal and 33 bacterial isolates were recovered and identified as Brucella melitensis or Brucella abortus by microbiology and AMOS-PCR. A Bayesian framework was implemented to estimate the true prevalence of the disease given an imperfect …

Waterhemp (Amaranthus Tuberculatus) In Soybean In Kentucky Conditions, Blake P. Patton

Theses and Dissertations--Plant and Soil Sciences

Waterhemp was a sporadic weed in Kentucky soybean production since the 1970’s. Waterhemp’s presence was not significant until the 1990’s after a widespread adoption of imazaquin and imazethapyr herbicides in the late 1980’s by Kentucky farmers which resulted in ALS-resistant waterhemp in some Kentucky areas. The introduction of glyphosate resistant soybeans in 1996 resulted in glyphosate-containing products being widely used by Kentucky farmers. Waterhemp populations resistant to glyphosate have occurred in Kentucky in the past few years. The majority of Kentucky soybeans are produced in some type of conservation tillage system, primarily to conserve soil and water, which is advantageous …

Nitrate Reduction Coupled To Iron(Ii) And Manganese(Ii) Oxidation In An Agricultural Soil, Stephanie Pyzola

Theses and Dissertations--Plant and Soil Sciences

New evidence shows iron(II) oxidation is strongly coupled to nitrate reduction under anaerobic conditions in freshwater sediments and agricultural soils. However, the contribution of iron(II) oxidation to nitrate reduction is unknown. Furthermore, oxidation of manganese(II) by nitrate has been largely overlooked. This study investigated nitrate-dependent iron(II) and manganese(II) oxidation in an agricultural soil (Sadler silt loam) using stirred-batch kinetic techniques with native soil organic carbon (SOC) as the electron donor and included addition of amendments (hydrogen gas and wheat residue). In the presence of native SOC, nitrate-dependent Fe(II) and Mn(II) oxidation occurred at early stages of the reaction while organic …

Calendula Officinalis Growth And Production Of Secondary Compounds In Greenhouse And Soil-Based Herbal Organic Production Systems, Victoria M. Anderson

Theses and Dissertations--Plant and Soil Sciences

Calendula officinalis is a useful model crop because calendula flowers are used both ornamentally and medicinally. Organic production systems have many challenges; among these is the synchrony of nitrogen mineralization with the requirements of the crop. Organic greenhouse substrates have significantly different initial nitrogen levels which influence the performance of calendula, the highest initial N and plant performance was found in the organic compost peat substrate (OCP). The addition of supplemental nitrogen improved performance, but only OCP performed as well as the conventionally fertilized peat-based substrate. The nitrogen mineralization patterns in a soil-based greenhouse pot experiment showed that highly processed …

Ecophysiological Responses Of Tall Fescue Genotypes To Endophyte Infection And Climate Change, Marie Bourguignon

Theses and Dissertations--Plant and Soil Sciences

Tall fescue is a widely used forage grass in the eastern USA and can form a symbiosis with a fungal endophyte, which can be beneficial for the plant but can cause livestock health issues. Little is known regarding the symbiotic response to predicted climate change. To address this knowledge gap, I analyzed tall fescue variety trial data collected throughout the U.S., exploring relationships between climate variables and yield for two different fescue cultivars that were either endophyte-free or infected. This study showed no endophyte or cultivar effect on fescue yield, but identified temperature, precipitation and location as significant predictors of …

Mass Selection With An Optical Sorter For Head Scab Resistance In Soft Red Winter Wheat, Hussein M. Khaeim

Theses and Dissertations--Plant and Soil Sciences

Fusarium head blight (FHB) or head scab, caused by Fusarium graminearum Schwabe [telomorph: Gibberella zeae Schwein.(Petch)], is one of the most destructive diseases of wheat (Triticum aestivum L.) worldwide. Numerous strategies for scab resistance breeding are in use, including phenotypic selection for low severity and marker-assisted selection for resistance QTL. The most destructive consequences of scab are evidenced through a reduction in grain quality, and the presence of mycotoxins, the most common of which is deoxynivalenol (DON). Thus, there is great interest among breeders in selecting for resistance to both of these traits. To this end, a study was …

Control Of Erwinia Tracheiphila In Cucumis Melo, John R. Caudle

Theses and Dissertations--Plant and Soil Sciences

Currently there is no control of bacterial wilt disease, Erwinia tracheiphila, in susceptible cucurbit crops, once infection of the plant occurs. Conventional and organic production systems rely on insecticide applications to kill the vectors, striped and spotted cucumber beetles, Acalymma vittatum and Diabrotica undecimpunctata, respectively, prior to transmission of the pathogen which indirectly controls the disease to some extent. Physical barriers such as row covers are used to exclude the vectors from plants prior to flowering; however, pollination requirements expose plants to potential infection. Experimental field plots were developed to test various enhanced organic production systems in an …

Nitrogen–Climate Interactions In Us Agriculture, G. Philip Robertson, Tom W. Bruulsema, Ron J. Gehl, David Kanter, Denise L. Mauzerall, C. Alan Rotz, Candiss O. Williams

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

Agriculture in the United States (US) cycles large quantities of nitrogen (N) to produce food, fuel, and fiber and is a major source of excess reactive nitrogen (Nr) in the environment. Nitrogen lost from cropping systems and animal operations moves to waterways, groundwater, and the atmosphere. Changes in climate and climate variability may further affect the ability of agricultural systems to conserve N. The N that escapes affects climate directly through the emissions of nitrous oxide (N₂O), and indirectly through the loss of nitrate (NO₃^-), nitrogen oxides (NO_x) and ammonia to downstream and …

How Does A Mycobacterium Change Its Spots? Applying Molecular Tools To Track Diverse Strains Of Mycobacterium Avium Subspecies Paratuberculosis, John Bannantine, L.-L. Li, Srinand Sreevatsan, Vivek Kapur

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

Defining genetic diversity in the wake of the release of several Mycobacterium avium subsp. paratuberculosis (MAP) genome sequences has become a major emphasis in the molecular biology and epidemiology of Johne’s disease research. These data can now be used to define the extent of strain diversity on the farm. However, to perform these important tasks, researchers must have a way to distinguish the many MAP isolates/strains that are present in the environment or host to enable tracking over time. Recent studies have described genetic diversity of the Mycobacterium avium complex (MAC), of which MAP is a member, through pulsed-field gel …

Interferon Gamma Responses To Proteome-Determined Specific Recombinant Proteins: Potential As Diagnostic Markers For Ovine Johne’S Disease, Valerie Hughes, Susan Denham, J. P. Bannantine, Francesca Chianini, Karen Kerr, Linda May, Joyce Mcluckie, Mintu Nath, Karen Stevenson

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

Johne’s disease (JD), or paratuberculosis is a fatal enteritis of animals caused by infection with Mycobacterium avium subspecies paratuberculosis (Map). There may be a long subclinical phase with no signs of clinical disease.

Diagnosis of JD is problematic and no test can reliably detect sub-clinical disease. Th1 responses to Map are believed to be activated first with a later switch to Th2 responses and progression to clinical disease. Detection of a cell-mediated response, indicated by interferon gamma (IFN-􏰁) produced in response to mycobacterial antigens, may give an early indication of infection. Crude extracts of Map (PPDj) have been used to …

Consumer's Preferences For Goat Meat In The United States : An Application Of Choice-Based Conjoint Analysis, Jessica Irene Hill

LSU Doctoral Dissertations

The meat goat industry is one of the fastest growing agricultural sectors in the United States. However, there has been limited research on consumers’ preferences for goat meat; therefore, a choice experiment was used to assess consumer preferences for goat meat and/or live goats. A national online survey was conducted from April 27, 2012 to May 4, 2012. Respondents were asked to complete either the goat meat choice experiment, live goat choice experiment or both. In addition to the choice experiment, respondents answered a set of questions about goat meat consumption and purchasing behavior as well as demographics. The attributes …

Empirical And Simulation Essays On Analyzing A Country's Export Performance : The Case Of Ghana, Aude L. Pujula

LSU Doctoral Dissertations

A large array of literature has revealed the complexity of export performance analysis. Using the case of Ghana, this dissertation, divided into three essays, seeks to provide the methodological guidance, empirical and simulation evidence necessary to analyze a country’s export performance. The choice of Ghana was motivated by the country’s growth experience, strong export and agricultural sectors and implemented reforms and programs since 1983. In the first essay, we created a new trade-weighted Cedi index or real effective exchange rate (REER) that takes into account Ghana’s most relevant patterns of trade and captures the evolution of Ghana’s export price competitiveness …

Be A Part Of The Plan - Engaging People - Linking The World, Charlotte Narjes

Cornhusker Economics

The Nebraska Broadband Planning Initiative, in its fourth year, is designed to increase adoption and utilization of broadband in communities and regions. Goals of this initiative include:

Increase adoption and utilization of Broadband in communities and regions with an emphasis on unserved and underserved regions.

Work as a region in developing regional Broadband plans that increase adoption and utilization of broadband.

Increase understanding of importance of Broadband as a foundation of economic growth.

The Initiative is focused around the following project areas:

Mapping

Planning (capacity building, technical assistance and regional planning).

Affordable Care Act And Your Ag Business, Marilyn R. Schlake, Carroll S. Welte, Charlotte Narjes, Jim Crandall

Cornhusker Economics

Implementation of the Affordable Care Act (ACA) is steadily moving forward. Whether you agree or disagree with the ACA, the fact is that it is currently the national law. Already we are seeing changes affecting how hospitals, doctors and insurance carriers operate. Regulations impacting individuals and businesses in the areas of benefits covered, maximum out-of-pocket costs, taxes and penalties began on October 1st. Spend time now to evaluate how these changes will affect you, your family and your business operations.

Insect Communities In Soybeans Of Eastern South Dakota: The Effects Of Vegetation Management And Pesticides On Soybean Aphids, Bean Leaf Beetles, And Their Natural Enemies, Jonathan G. Lundgren, Louis S. Hesler, Sharon A. Clay, Scott F. Fausti

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

Although most pests of soybeans, Gycine max (L.), in the Northern Great Plains are managed using pesticides, farm management practices that encourage biodiversity offer promising long-term, sustainable solutions for controlling insect and weed pests profitably. The recent invasion of the Northern Great Plains by the soybean aphid (Aphis glycines Matsumura; Hemiptera: Aphididae) has had potentially important implications for insect communities in soybeans of this region, although recent descriptions of this regional community are scarce. We describe how three pest management systems that vary in the intensity with which they rely on herbicides and insecticides (chemically intensive, reduced chemical, and …

Intergenerational Farm Family Communication And Succession Planning, Cayla M. Waters

Communication & Leadership Dissertations and Theses

This thesis studies intergenerational communication in farm families during the succession planning process. The research focuses on intergenerational relationships between fathers and sons. Due to the lack of research on intergenerational communication in farm families, this thesis examines the role communication plays in this relationship, and how communication affects the succession planning process of passing down the family farm. Communication accommodation theory is used to understand the communication processes taking place within the father-son relationship. The research methods used to gather information for this study are focus groups. The focus groups are made up of 3 father/son pairs who are …

Mining Climate Data For Shire Level Wheat Yield Predictions In Western Australia, Yunous Vagh

Theses: Doctorates and Masters

Climate change and the reduction of available agricultural land are two of the most important factors that affect global food production especially in terms of wheat stores. An ever increasing world population places a huge demand on these resources. Consequently, there is a dire need to optimise food production.

Estimations of crop yield for the South West agricultural region of Western Australia have usually been based on statistical analyses by the Department of Agriculture and Food in Western Australia. Their estimations involve a system of crop planting recommendations and yield prediction tools based on crop variety trials. However, many crop …

Is There A Best Cow Size For Beef Cattle Producers?, Matthew Stockton, Sunil P. Dhoubhadel, Leslie Aaron Stalker

Cornhusker Economics

There are individuals in the beef cattle industry who claim there is a need for smaller brood cows, because smaller cows are more efficient and therefore more profitable. On the other hand, there are those who claim the larger the cow the better, and these generally are those who feed calves to slaughter. The proponents of both sides seem to have logical reasons that support their claims. So who is right?

Recycling In Utah: Paper, Rebecca Mills, Craig Pearson

All Current Publications

This factsheet is part of a series highlighting different recyclable commodities and focuses on paper recycling.