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Ethylene Production As An Indicator Of Stress Conditions In Hydroponically-Grown Strawberries, Justin Donald Hogan

Theses, Dissertations and Capstones

With the worldwide phaseout of methyl bromide, the use of hydroponic systems has increased as an economic alternative for the growth of many horticulturally-important crops, including strawberries. In this study, the effect of hydroponics on strawberry plant physiology was examined by first measuring ethylene levels, a plant hormone known to increase due to stressful conditions, and plant growth and yield. Using a gas chromatograph, ethylene was measured from plants which showed that light and temperature have minimal effects, but placement of plants could have an effect on plant growth and yield. Next, the mechanism of ethylene production was examined by …

Evaluation Of Different Insecticides And Fabric Types For Development Of Treated Targets For Stable Fly (Diptera: Muscidae) Control, Jerome Hogsette, Alyce Nalli, Lane Foil

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

Stable fly, Stomoxys calcitrans (L.) (Diptera: Muscidae), once only a pest of pastured cattle, has become a serious pest of range cattle in the United States. Because of the difficulties associated with stable fly management under range conditions, a pesticide-impregnated cloth target is being developed as a management tool. We conducted studies to determine the influence of weather, time, fabric type, insecticide type, and insecticide concentration on the mortality of stable flies from a susceptible laboratory colony exposed for 30 s to treated cloth targets. We found that 100% of the flies exposed to trigger (Trigger-Royal Box, 65% polyester and …

Effect Of Lures And Trap Placement On Sand Fly And Mosquito Traps, Ulrich R. Bernier, David F. Hoel, Jerome Hogsette, Hanafi A. Hanafi, Daniel Kline

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

Catches of mosquitoes and sand flies in CO₂ traps baited with three different lures and an unbaited control were compared. The lures examined were carbon dioxide, carbon dioxide plus l-octen-3-ol, and carbon dioxide plus human hair in ethanol. Studies using a 4 x 4 Latin square design, with 3 sets of 4 consecutive trap nights, were conducted between August 6 and September 10, 2007. The study site was the Bahrif Village, Aswan, Egypt. This location had high percentage of Phlebotomus papatasi in sand fly populations, and the low incidence of human cases of leishmaniasis. There were 2,152 sand flies …

Managing And Enhancing Switchgrass As A Bioenergy Feedstock, Robert B. Mitchell, Kenneth Vogel

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

The United States Department of Energy (DOE) has identified switchgrass (Panicum virgatum L.) as a viable perennial herbaceous feedstock for cellulosic ethanol production. Although switchgrass bioenergy research was initiated by USDA-ARS, Lincoln, NE, USA in 1990, switchgrass research has been conducted at this location since the 1930s. Consequently, a significant amount of genetic and agronomic research on switchgrass has been conducted for the Corn Belt and Central Great Plains of the USA that is directly applicable to its use as a biomass energy crop. Similar research must be conducted in other major agroecoregions to verify or modify switchgrass management …

Effects Of Agricultural Conservation Practices On Fish And Wildlife Volume 2, Stuart R. Gagnon, Joseph R. Makuch, Cassandra Y. Harper

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

This bibliography, in two volumes, is part of a multi-volume set developed by the Water Quality Information Center at the National Agricultural Library in support of the United States Department of Agriculture’s Conservation Effects Assessment Project (CEAP). The bibliography is a guide to recent scientific literature covering effects of agricultural conservation practices on fish and wildlife. The citations listed here provide information on how conservation programs and practices designed to improve fish and wildlife habitat, as well as those intended for other purposes, e.g., water quality improvement, affect various aquatic and terrestrial fauna.

Interannual Variability In Carbon Dioxide Fluxes And Flux–Climate Relationships On Grazed And Ungrazed Northern Mixed-Grass Prairie, H. Wayne Polley, Albert B. Frank, Joaquin Sanabria, Rebecca L. Phillips

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

The annual carbon (C) budget of grasslands is highly dynamic, dependent on grazing history and on effects of interannual variability (IAV) in climate on carbon dioxide (CO₂) fluxes. Variability in climatic drivers may directly affect fluxes, but also may indirectly affect fluxes by altering the response of the biota to the environment, an effect termed ‘functional change’.

Effects Of Agricultural Conservation Practices On Fish And Wildlife, Stuart R. Gagnon, Joseph R. Makuch, Cassandra Y. Harper

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

This bibliography, in two volumes, is part of a multi-volume set developed by the Water Quality Information Center at the National Agricultural Library in support of the U.S. Department of Agriculture’s Conservation Effects Assessment Project (CEAP). The bibliography is a guide to recent scientific literature covering effects of agricultural conservation practices on fish and wildlife. The citations listed here provide information on how conservation programs and practices designed to improve fish and wildlife habitat, as well as those intended for other purposes, e.g., water quality improvement, affect various aquatic and terrestrial fauna.

Environmental Management Of Grazing Lands Final Report, Kevin Wagner, Larry Redmon, Terry Gentry, Darren Harmel, Allan Jones

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

Bacteria levels are the number one cause of water quality impairment in Texas. Several recent Total Maximum Daily Loads (TMDLs) in Texas, such as those implemented in the Peach Creek and Leon River watersheds, have identified grazing cattle as a contributor to bacterial water quality impairments in those watersheds through both direct deposition and runoff of their fecal matter to streams. To address this issue, the Texas State Soil and Water Conservation Board (TSSWCB) and the Natural Resources Conservation Service (NRCS) funded this project to assist with development and delivery of technical information and support to ranchers on protection and …

Tillage Effects On Soil Quality Indicators And Nematode Abundance In Loessial Soil Under Long- Term No-Till Production, R. B. Mendoza, T. G. Franti, John W. Doran, Thomas O. Powers, C. W. Zanner

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

Soil quality indicators and nematode abundance were characterized in a loessial soil under long-term conservation tillage to evaluate the effects of no-till, double-disk, chisel, and moldboard plow treatments. Indicators included soil electrical conductivity (EC), soil texture, soil organic matter (SOM), and total particulate organic matter (tPOM). Nematode abundance was positively correlated with EC, silt content, and total POM and negatively correlated with clay content. Clay content was the main source of variation among soil quality indicators and was negatively correlated with nematode abundance and most indicators. The gain in SOM in the no-till system amounted to 10887 kg over the …

Characterization Of Biological Types Of Cattle: Indicator Traits Offertility In Beef Cows, R. A. Cushman, M. F. Allan, L. A. Kuehn

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

Genetic diversity among breeds of cattle allows producers to select animals for specific environments or market conditions. Reproductive efficiency is a multi-component trait that is largely influenced by environmental influences such as health and nutritional status; however, there are clearly genetic components to reproductive efficiency, and breed differences in a number of indicator traits associated with fertility and cow productivity have been identified. Historical indicators of fertility include scrotal circumference, age at puberty, and postpartum interval. Both age at puberty and postpartum interval are laborious traits to collect in heifers and cows because they require many days of detection of …

Chapter 8. The Importance And Role Of Watersheds In The Transport Of Nitrogen, T. J. Sauer, R. B. Alexander, J. V. Brahana, R. A. Smith

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

A recent report to Congress concerning water quality in the United States indicated that 35%, 45%,and 44'% of the assessed rivers and streams, lakes, and estuaries, respectively, were impaired by one or more pollutants (US Environmental Protection Agency, 1999). Nutrients, primarily nitrogen (N) and phosphorus (P), contributed to the impairment of 30% or 135,000 km of the nation's impaired rivers and streams. 44% of the impaired lakes, and 23% of the impaired estuaries. Excessive nutrient loads are implicated in the eutrophication of lakes and reservoirs in the United States and coastal ecosystems where N is most limiting to primary productivity …

Chapter 2. Transformation And Transport Processes Of Nitrogen In Agricultural Systems, Ronald Follett

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

This chapter discusses the transformation and transport processes of nitrogen (N) in agricultural systems and provides information on overall reservoir sizes for N. Nitrogen is ubiquitous in the environment and is required for the survival of all living things. It is also one of the most important essential nutrients and is central to the production of all crop plants. The most abundant form of N in the environment is elemental dinitrogen (N₂) gas that accounts for 78% of the atmosphere. N₂ gas is inert and is not directly available for plant uptake and metabolism. The atmospheric reservoir …

Chapter 7. Nitrogen In Groundwater Associated With Agricultural Systems, M. R. Burkartaus D, J. D. Stoner

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

Nitrogen, particularly in the form of nitrate, is the most common contaminant in aquifer systems (Freeze and Cherry, 1979). Hallberg (1989) points to agriculture as the most substantial anthropogenic source of nitrate, and Keeney (1986) suggests that this is caused by the intensive and extensive land-use activities associated with crops and animal production. The discussion of the occurrence of nitrogen in groundwater beneath agricultural systems is presented by examining the factors influencing aquifer vulnerability to nitrogen contamination, and by characterizing the geographic distribution of groundwater contamination by nitrogen. Factors that influence aquifer vulnerability are presented in the context of exposure …

Auditing And Assessing Air Quality In Concentrated Feeding Operations, N. A. Cole, R. Todd, B. Auvermann, D. B. Parker

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

The potential adverse effects of concentrated animal feeding operations (CAFO) on the environment are a growing concern. The air quality issues of most concern to CAFO vary but generally include ammonia, hydrogen sulfide, particulate matter, volatile organic compounds, greenhouse gases, and odors. Air pollutants may be regulated by federal and state laws or by nuisance complaints. The United States Environmental Protection Agency, and poultry, swine, and dairy industries recently agreed to the National Air Emissions Monitoring System to fund research on atmospheric emissions from production farms in the United States. Air quality regulations may be based on actual emissions, atmospheric …

Chapter 1. The Nitrogen Cycle, Historical Perspective, And Current And Potential Future Concerns, D. R. Keeney, J. L. Hatfield

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

Nitrogen (N) along with carbon and oxygen is the most complex and crucial of the elements essential for life. Supplementing grain and grass forage crops with organic and inorganic N fertilizers has long been recognized as a key to improving crop yields and economic returns. Globally. N fertilizer is largely used for cereal grain production and accounts for an estimated 40(1r of the increase in per capita food production in the past 50 years (Mosier et al.. 200 I). Smil (200 I) estimates that N fertilizer supplies up to 40% of the world's dietary protein and dependence on N from …

Nitrogen Capture By Grapevine Roots And Arbuscular Mycorrhizal Fungi From Legume Cover-Crop Residues Under Low Rates Of Mineral Fertilization, Xiaomei Cheng, Amy Euliss, Kendra Baumgartner

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

The influence of mineral fertilization on root uptake and arbuscular mycorrhizal fungi-mediated ¹⁵N capture from labeled legume (Medicago polymorpha) residue was examined in winegrapes (Vitis vinifera) in the greenhouse, to evaluate compatibility of fertilization with incorporation of cover-crop residue in winegrape production. Plants grown in marginal vineyard soil were either fertilized with 0.25× Hoagland’s solution or not. This low fertilization rate represents the deficit management approach typical of winegrape production. Access to residue in a separate compartment was controlled to allow mycorrhizal roots (roots + hyphae), hyphae (hyphae-intact), or neither (hyphae-rotated) to proliferate in the …

The First Five Years Of The Conservation Effects Assessment Project, Lisa F. Duriancik, Dale Bucks, James P. Dobrowolski, Tom Drewes, S. Diane Eckles, Leonard Jolley, Robert L. Kellogg, Daryl Lund, Joseph R. Makuch, Michael P. O’Neill, Charles A. Rewa, Mark R. Walbridge, Roberta Parry, Mark A. Weltz

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

The Conservation Effects Assessment Project (CEAP) was initiated by the USDA Natural Resources Conservation Service (NRCS), Agricultural Research Service (ARS), and Cooperative State Research, Education, and Extension Service (CSREES) in response to a general call for better accountability of how society would benefit from the 2002 farm bill’s substantial increase in conservation program funding (Mausbach and Dedrick 2004). The original goals of CEAP were to establish the scientific understanding of the effects of conservation practices at the watershed scale and to estimate conservation impacts and benefits for reporting at the national and regional levels. Other federal agencies and nongovernmental organizations …

Endocrine Responses Of Fast- And Slow-Growing Families Of Channel Catfish, Brian C. Peterson, Brian C. Small, Geoffrey C. Waldbieser, Brian G. Bosworth

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

Sixty-eight families of USDA303 channel catfish Ictalurus punctatus were evaluated for growth performance for 30 d. The fastest- and slowest-growing catfish families were further evaluated to examine the hypothesis that genes or gene products associated with the growth regulatory and stress axes can be used to describe differences in growth performance. Research examined mRNA levels of genes involved in the growth hormone–insulin-like growth factor (GH–IGF) network in fast- (family A) and slow-growing (family H) USDA303 catfish. Fish (59.0 ± 2.4 g) were fed for 7 weeks, weighed, and had tissues for RNA extraction. The remaining fish were subjected to an …

History And Ecological Basis For Areawide Pest Management, Norman C. Elliott, David W. Onstad, Michael J. Brewer

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

The traditional approach to pest management is to treat the crop or commodity in a particular management unit before an economically significant infestation of the pest has developed. Determining the need to take corrective action is based on the economic threshold concept, which forms the basis of most integrated pest management programmes (Metcalf and Luckman, 1975). Areawide pest management (AWPM) can be contrasted with traditional pest management in that pest management tactics are used over a broad spatial area, often treating the whole area simultaneously to maintain the pest below economic levels or, in some cases, completely eradicate it. A …

Salt Cedar Areawide Pest Management In The Western Usa, Raymond I. Carruthers, C. Jack Deloach, John C. Herr, Gerald L. Anderson, Allen E. Knutson

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

Salt cedar (Tamarix spp. (Tamaricaceae: Tamaricales)) is a group of exotic shrubs to small trees that have invaded many riparian areas and lake shores across western North America. Of the 54 species known worldwide (Baum, 1967, 1968), ten species of salt cedars have been introduced into the USA (Crins, 1989), primarily from their countries of origin across Europe and Central Asia. They are also native in Africa and the Indian subcontinent of Asia. No species from the entire family Tamaricaceae are native to North America, and only a restricted group of six species of more distantly related …

A Gel-Based Reference Map Of The Porcine Hepatocyte Proteome, Thomas J. Caperna, Amy E. Shannon, Wesley M. Garrett

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

The overall goal of our research is to characterize and identify gene expression profiles of porcine hepatic cells. In this study, we have prepared two-dimensional electrophoresis maps of cytosol and membrane fractions from freshly prepared hepatocytes which were pooled from three crossbred pigs (35–69 kg). Following isoelectric focusing with three pH range immobilized pH gradient strips (pH 3–6, 5–8 and 7–10) and staining the second dimension gels with colloidal Coomassie blue, 728 protein spots were picked and digested with trypsin. Extracted tryptic peptides were initially subjected to matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI–TOF-MS) analysis for identification of proteins …

Nuclear Targeting By Fragmentation Of The Potato Spindle Tuber Viroid Genome, Asta Abraitiene, Yan Zhao, Rosemarie Hammond

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

Transient expression of engineered reporter RNAs encoding an intron-containing green fluorescent protein (GFP) from a Potato virus X-based expression vector previously demonstrated the nuclear targeting capability of the 359 nucleotide Potato spindle tuber viroid (PSTVd) RNA genome. To further delimit the putative nuclear-targeting signal, PSTVd subgenomic fragments were embedded within the intron, and recombinant reporter RNAs were inoculated onto Nicotiana benthamiana plants. Appearance of green fluorescence in leaf tissue inoculated with PSTVd-fragment-containing constructs indicated shuttling of the RNA into the nucleus by fragments as short as 80 nucleotides in length. Plant-to-plant variation in the timing of intron removal and subsequent …

Hessian Fly, Jeffrey J. Stuart, Ming-Shun Chen, Marion O. Harris

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

The Hessian fly (Mayetiola destructor) is a gall-forming insect (Harris et al. 2006) with several attributes that make it suitable for genetic analysis: a short life cycle (30 days), a small genome (158 Mb) (Johnston et al. 2004), and polytene chromosomes. The reproductive biology and behavior of the insect also make it an attractive model (Harris and Rose 1989,1990; Bergh et al. 1990; Kanno and Harris 2000; Morris et al. 2000; Harris et al. 2001). Compared to most plant-feeding insects, Hessian flies can be reared in a small space. Unlike gall-forming aphid species, the Hessian fly is always …

Uncertainty In Environmental Decision Making: Issues, Challenges And Future Directions, H. R. Maier, J. C. Ascough, M. Wattenbach, C. S. Renschler, W. B. Labiosa, J. K. Ravalico

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

There has been an increase in the use of formal approaches to environmental management. Jakeman and Letcher (2003) and Jakeman et al. (2006) have demonstrated the importance of integrated models as a means of assessing the response of environmental systems to proposed enlargement options. Gunderson and Holling (2000), Cowie and Borrett (2005), Curtis et al. (2005) and Pahl-Wostl (2005) have highlighted the need for the incorporation of social and institutional aspects into decision-making processes.

Effects Of Atmospheric Co2 Enrichment On Crop Nutrient Dynamics Under No-Till Conditions, Stephen A. Prior, G. Brett Runion, Hugo H. Rogers, H. Allen Torbert

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

Increasing atmospheric CO₂ concentration could increase crop productivity and alter crop nutrient dynamics. This study was conducted (3 yrs) with two crops ([Glycine max (L.) Merr.] and grain sorghum [Sorghum bicolor (L.) Moench.]) grown under two CO₂ levels (ambient and twice ambient) using open top field chambers on a Blanton loamy sand under no-tillage. Macronutrient and micronutrient concentrations and contents were determined for grain, stover, and roots. Although elevated CO₂ tended to reduce nutrient concentrations, high CO₂ consistently increased nutrient content especially in grain tissue; this response pattern was more notable with macronutrients. The …

Good Vibrations? Structure And Function Of The Cloacal Tip Of Male Australian Maluridae, Melissah Rowe, Murray R. Bakst, Stephen Pruett-Jones

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

When females mate multiply, sperm competition can generate strong selection for traits that provide males with a fertilisation advantage. This study examined the cloacal tip, a unique morphological structure of males that appears to be associated with sperm competition in Australian Maluridae. Species in this group appear to experience a range of sperm competition intensities and exhibit a diversity of associated reproductive adaptations and behaviours. A prominent cloacal tip was present in the striated grasswren Amytornis striatus striatus, and superb Malurus cyaneus cyanochlamys, splendid M. splendens melanotus, red-backed M. melanocephalus and white winged fairy-wrens M. leucopterus leuconotus …

General Introduction To Areawide Pest Management, Robert M. Faust

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

Welcome to the realm of areawide pest management (AWPM). This book represents one of the first comprehensive 'treatises' on the AWPM concept and approach, and should be of interest and use to many types of readers, from research scientists in government, university and industry to pest control advisors and extension personnel, growers, pest control and integrated pest management (IPM) practitioners, students, teachers, natural resource managers and others interested in environmentally sound pest control. There is a range of topics included in the subject area. The book is grouped into three parts. Chapters 2-8 discuss the foundation of areawide pest management; …

Establishing Inter-Agency, Multidisciplinary Areawide Pest Management Programmes, Robert M. Nowierski, Hendrik J. Meyer

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

Pest management today usually comprises multiple complex tactics that transcend disciplines, geographical regions, climatic zones, production/management systems, production scales and economic strata. Solutions to priority problems involve research, education and extension professionals. But, equally important to project success are the users of the knowledge generated and the end-users of the 'products'. Setting a direction for the future goals, IPM has been an important activity for the 'community' of constituents who share concerns for future pest management.

Under the leadership of the USDA and land grant universities, a road map for IPM has been developed with extensive participation of diverse stakeholders. …

Social And Economic Aspects Of Areawide Pest Management, Sean P. Keenan, Paul A. Burgener

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

This chapter explores demonstration elements from the United States Department of Agriculture, Agricultural Research Service's demonstration programme for cereal aphid AWPM. We explore elements of the demonstration programme as agricultural innovations. We discuss potential adoption of these elements by wheat producers on the Great Plains and implications of the programme outcomes for other wheat-growing regions of the world. We begin with a history of research on the adoption of agricultural innovations, which provides the context for evaluating the cereal aphid programme from the perspective of farmer adoption. Chapter 19, this volume, by Kristopher Giles et al. provides a summary and …

The Role Of Databases In Areawide Pest Management, Vasile Catana, Norman Elliott, Kris Giles, Mustafa Mirik, David Porter, Gary L. Hein, Frank Peairs, Jerry Michels

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

The simplest definition of the term 'database' is given in Webster's dictionary as 'a comprehensive collection of related data organized for convenient access, generally in a computer' (Random House, 1996). This term appeared in the late 1960s because of the evolution of computer software and the need to distinguish the specialized computer systems for the storage and manipulation of data, called database management systems (DBMS) (Neufeld and Cornog, 1986). Today, the acronym 'DBMS' is universally understood within Information Technology (IT), just like the acronym 'Bt' for 'Bacillus thuringiensis' is in the field of biological pest control. …