Life Sciences Commons^™

Bird Use Of Grain Fields And Implications For Habitat Management At Airports, Raymond B. Iglay, Bruce N. Buckingham, Thomas W. Seamans, James A. Martin, Bradley F. Blackwell, Jerrold L. Belant, Travis L. Devault

USDA Wildlife Services: Staff Publications

Airport properties often include agricultural land cover that can attract wildlife species hazardous to aircraft, despite recommendations against row crops near air operations areas. However, few studies have directly quantified bird use of corn, wheat, and soybean fields relative to bird-aircraft collision (strike) hazard levels to support land cover recommendations. Therefore, we compared bird use among corn, wheat and soybean fields and predicted that corn and wheat would attract bird species recognized as hazardous to aviation. We also anticipated that soybeans would pose minimal attraction to such birds. Here, hazard ranking (low to extremely high) reflects the percentage of strikes …

Studies On Asparagine In Nebraska Wheat And Other Grains, Sviatoslav Navrotskyi

Department of Food Science and Technology: Dissertations, Theses, and Student Research

Understanding of the contribution of environmental and genetic factors on the chemical composition of different grains is a critical issue in the area of food safety of cereal products. Numerous studies have reported that asparagine can form acrylamide, a toxic and potentially carcinogenic precursor compound, during a Milliard reaction. Therefore, studying the environmental and genetic effects that contribute to accumulation of asparagine in wheat and proso millet lines, which were grown in the state of Nebraska, is important for supporting breeding programs aimed at providing safer crops for consumers. In the realm of reduction of the asparagine concentration in wheat-based …

Comparison Of Hermetic Storage Of Wheat With Traditional Storage Methods In India, Pavel Somavat, Haibo Huang, Sunil Kumar, Mukesh K. Garg, Mary-Grace C. Danao, Vijay Singh, Marvin R. Paulsen, Kent D. Rausch

Department of Food Science and Technology: Faculty Publications

India is among the countries experiencing high postharvest losses. Four hermetic bags, two metallic bins, and two gunny bag (also known as jute or burlap bag) piles each containing 1 tonne of wheat were instrumented with temperature, relative humidity, and carbon dioxide sensors. Representative samples from each structure were collected each month and tests for moisture, germination, insect-damaged grain, and milling yield were performed. After nine months, wheat stored in hermetic bags had higher germination (87%) and lower insect-damaged grain percentages (0% to 0.33% with a mean value of 0.2%). Hermetic bags with deliberately introduced Rhyzopertha dominica successfully eliminated the …

Reducing The Potential For Acrylamide Formation In Wheat Products, Amy Hauver, P. Stephen Baenziger, Mary J. Guttieri

UCARE Research Products

Acrylamide, a chemical formed from free asparagine and reducing sugars during high-temperature cooking via the Maillard reaction (i.e. frying or baking) of high starch foods is deemed ‘probably carcinogenic to humans’ based on its affect in mice. In April of 2002, a group of Swedish researchers reported findings that presented evidence that heat-treated, starch-rich foods contained high levels of acrylamide, later linking the production of acrylamide to the Maillard reaction. A number of other studies have been done to link dietary intake of acrylamide to human cancers and other health effects, although many have had inconclusive results. Nevertheless, the World …

Impact Of Derived Global Weather Data On Simulated Crop Yields, Justin Van Wart, Patricio Grassini, Kenneth Cassman

Department of Agronomy and Horticulture: Faculty Publications

Crop simulation models can be used to estimate impact of current and future climates on crop yields and food security, but require long-term historical daily weather data to obtain robust simulations. In many regions where crops are grown, daily weather data are not available. Alternatively, gridded weather databases (GWD) with complete terrestrial coverage are available, typically derived from: (i) global circulation computer models; (ii) interpolated weather station data; or (iii) remotely sensed surface data from satellites. The present study’s objective is to evaluate capacity of GWDs to simulate crop yield potential (Yp) or water-limited yield potential (Yw), which can serve …

The Effect Of Temperature, Relative Humidity, And Virus Infection Status On Off-Host Survival Of The Wheat Curl Mite (Acari: Eriophyidae), E. N. Wosula, A. J. Mcmechan, G. L. Hein

Department of Entomology: Faculty Publications

The wheat curl mite, Aceria tosichella Keifer, is an eriophyid pest of wheat, although its primary economic impact on wheat is due to the transmission of Wheat streak mosaic (WSMV), Wheat mosaic (also known as High Plains virus), and Triticum mosaic (TriMV) viruses. These viruses cause significant annual losses in winter wheat production throughout the western Great Plains. Temperature and humidity are factors that often influence arthropod survival, especially during dispersal from their hosts, yet the impact of these two factors on off-host survival has not been documented for wheat curl mite. Pathogen- infected host plants often influence the biology …

Potential For Crop Production Increase In Argentina Through Closure Of Existing Yield Gaps, Fernando Aramburu Merlos, Juan Pablo Monzon, Jorge L. Mercau, Miguel Taboada, Fernando H. Andrade, Antonio J. Hall, Esteban Jobbagy, Kenneth Cassman, Patricio Grassini

Department of Agronomy and Horticulture: Faculty Publications

Favorable climate and soils for rainfed crop production, together with a relatively low population density,results in 70–90% of Argentina grain production being exported. No assessment to date has tried to estimate the potential for extra grain production for soybean, wheat and maize, which account for 78%of total harvested area, by yield gap closure on existing cropland area and its impact at a global scale.The objectives of this paper are (i) to estimate how much additional grain could be produced without expanding crop area by closing yield gaps in Argentina, (ii) to investigate how this production and yield gaps varies across …

Population Dynamics Of Triticum Mosaic Virus In Various Host Species, Melissa S. Bartels

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

It has been established that RNA viruses should be genetically diverse, due to the high error rate of their RNA-dependent RNA polymerases and the lack of proof-reading capabilities. Plant RNA viruses are not as genetically diverse as expected. Evolutionary factors, such as purifying selection and bottlenecks that favor genetic stability, might be affecting plant viral populations. Otherwise RNA virus populations, with their potential for extreme diversity, might acquire a lethal number of mutations leading to the collapse of the population.

Triticum mosaic virus (TriMV) populations maintained in a controlled greenhouse environment displayed genetic stability. The mutation frequency per nucleotide of …

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 …

Estimating Crop Yield Potential At Regional To National Scales, Justin Van Wart, Kurt Christian Kersebaum, Shaobing Peng, Maribeth Milner, Kenneth Cassman

Department of Agronomy and Horticulture: Faculty Publications

World population will increase 35% by 2050, which may require doubling crop yields on existing farm land to minimize expansion of agriculture into remaining rainforests, wetlands, and grasslands. Whether this is possible depends on closing the gap between yield potential (Yp, yield without pest, disease, nutrient or water stresses, or Yw under water-limited rainfed conditions) and current average farm yields in both developed and developing countries. Quantifying the yield gap is therefore essential to inform policies and prioritize research to achieve food security without environmental degradation. Previous attempts to estimate Yp and Yw at a global level have been too …

Evidence Of Transmission Of Escherichia Coli O157:H7 To The Tissues Or Phyllo-Plane Of Wheat, From Contaminated Soil, Seeds Or Water, Bismarck Antonio Martinez

Department of Food Science and Technology: Dissertations, Theses, and Student Research

Escherichia coli O157:H7 is a human pathogen that can cause a wide spectrum of disease symptoms, such as bloody diarrhea, hemorrhagic colitis, and hemolytic uremic syndrome (HUS). Escherichia coli O157:H7 illness are mainly associated with undercooked beef; however, in recent years outbreaks have been linked to fresh produce such as spinach, lettuce, and sprouts. In 2009, flour was implicated as a contamination source in the consumption of raw cookie dough resulting in 77 illness-cases. The objective of this research was to determine the possible route of transmission of E. coli O157:H7 into the phyllo-plane of wheat using contaminated seed, soil …

Transmission Of Triticum Mosaic Virus And Its Impact On The Biology Of The Wheat Curl Mite Aceria Tosichella Keifer (Eriophyidae), And An Evaluation Of Management Tactics For The Wheat Curl Mite And The Wheat-Mite-Virus Complex, Anthony J. Mcmechan

Department of Entomology: Dissertations, Theses, and Student Research

The wheat-mite-virus complex is an important production constraint to winter wheat production in the Great Plains, and consists of three viruses; wheat streak mosaic (WSMV), wheat mosaic (WMoV) and Triticum mosaic virus (TriMV). Synergistic interactions between these viruses have resulted in increased rates of replication and transmission of viruses, thus increasing the potential impact on wheat yields. The wheat curl mite (WCM), Aceria tosichella Keifer is the only known vector of the viruses within the wheat-mite-virus complex.

Currently, three colonies of WCM have been characterized by differential responses to mite resistant genes (biotypes) in wheat and differential transmission of WMoV. …

Modulation Of Kernel Storage Proteins In Grain Sorghum (Sorghum Bicolor (L.) Moench), Tejinder Kumar, Ismail M. Dweikat, Shirley Sato, Zhengxiang Ge, Natalya Nersesian, Han Chen, Thomas Elthon, Scott Bean, Brian P. Ioerger, Mike Tilley, Thomas E. Clemente

Department of Agronomy and Horticulture: Faculty Publications

Sorghum prolamins, termed kafirins, are categorized into subgroups α, β, and γ. The kafirins are co-translationally translocated to the endoplasmic reticulum (ER) where they are assembled into discrete protein bodies that tend to be poorly digestible with low functionality in food and feed applications. As a means to address the issues surrounding functionality and digestibility in sorghum, we employed a biotechnology approach that is designed to alter protein body structure, with the concomitant synthesis of a co-protein in the endosperm fraction of the grain. Wherein perturbation of protein body architecture may provide a route to impact digestibility by reducing disulphide …

Triticum Mosaic Poacevirus Enlists P1 Rather Than Hc-Pro To Suppress Rna Silencing-Mediated Host Defense, Satyanarayana Tatineni, Feng Qu, Ruhui Li, Thomas Jack Morris, Roy French

Nebraska Center for Virology: Faculty Publications

Triticum mosaic virus (TriMV) is the type species of the newly established Poacevirus genus in the family Potyviridae. In this study, we demonstrate that in contrast to the helper component- proteinase (HC-Pro) of Potyvirus species, the P1 proteins of TriMV and Sugarcane steak mosaic poacevirus function in suppression of RNA silencing (SRS). TriMV P1 effectively suppressed silencing induced by single- or double-stranded RNAs (ss/ds RNAs), and disrupted the systemic spread of silencing signals at a step after silencing signal production. Interestingly, contrary to enhanced SRS activity of potyviral HC-Pro by co-expression with P1, the presence of TriMV HC-Pro reduced …

Comparing Cropping System Productivity Between Fixed Rotations And A Flexible Fallow System Using Modeling And Historical Weather Data In The Semi-Arid Central Great Plains, Juan Jose Miceli-Garcia

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

In the Central Great Plains, the predominant crop rotation is winter wheat (Triticum aestivum L.)-fallow. Producers are looking to add diversity and intensity to their cropping systems by adding summer crops, however, the elimination of summer fallow may increase crop production risk. The objective of this study was to use crop simulation modeling to compare the productivity of two fixed rotations [winter wheat-corn (Zea mays L.)-fallow and winter wheat-corn-spring triticale (X Triticosecale Wittmack)] with simulated flexible fallow rotations. The flexible fallow rotations made the decision to plant triticale or use summer fallow prior to winter wheat seeding based …

Fusarium Head Blight: Winter Wheat Cultivar Responses And Characterization Of Pathogen Isolates, John Fredy Hernandez Nopsa

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

Fusarium head blight (FHB) is a destructive disease of wheat (Triticum aestivum L). FHB reduces yield and grain quality and causes accumulation of the mycotoxin deoxynivalenol (DON) in grain. Cultivar resistance is one of the most effective management strategies for FHB. Experiments were conducted to 1) identify winter wheat cultivars with resistance to FHB and DON accumulation, 2) determine the effect of winter wheat cultivar on the relationship between FHB and DON concentration, and 3) identify the major species of Fusarium causing FHB in Nebraska and characterize its isolates. Differences (P ≤ 0.05) were detected among cultivars in FHB …

Grain Yield And Yield-Related Qtl Validation Using Reciprocal Recombinant Inbred Chromosome Lines In Wheat, Neway C. Mengistu

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

Grain yield and yield-related traits are the most important economic factors for bread wheat (Triticum aestivum L.) improvement. Grain yield (GYLD) and yield-related quantitative trait loci (QTLs) were previously identified by using a population of recombinant inbred chromosome lines (RICLs) developed from cultivar ‘Cheyenne’ (CNN) and its substitution line CNN(WI3A), where the 3A chromosome of cultivar ‘Wichita’ (WI) was substituted for the CNN chromosome 3A. The objectives of this study were to identify and validate GYLD and yield-related QTLs previously identified in CNN(RICLs-3A) studies by using the mirror population WI(RICLs-3A), where chromosome 3A of CNN and WI were now …

A Novel Codominant Marker For Selection Of The Null Wx-B1 Allele In Wheat Breeding Programs, Mika Saito, Patricia Vrinten, Goro Ishikawa, Robert A. Graybosch, Toshiki Nakamura

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

Waxy protein (granule-bound starch synthase I) is a key enzyme in the synthesis of amylose in endosperm tissue. The amylose content of wheat flour plays a significant role in determining Japanese udon noodle quality. Most wheat cultivars suitable for producing udon noodles have a low amylose level due to a lack of Wx-B1 protein conditioned by null Wx-B1 alleles. It was previously determined that the entire coding region of the wheat Wx-B1 gene is deleted in the most common null allele. However, the extent and breakpoints of the deletion have not been established. In this study, the position of the …

Opportunities And Roadblocks In Utilizing Forages And Small Grains For Liquid Fuels, Gautam Sarath, Robert B. Mitchell, S. E. Sattler, Deanna L. Funnell, Jeffrey F. Pedersen, Robert A. Graybosch, Kenneth P. Vogel

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

This review focuses on the potential advantages and disadvantages of forages such as switchgrass (Panicum virgatum), and two small grains: sorghum (Sorghum bicolor), and wheat (Triticum aesitvum), as feedstocks for biofuels. It highlights the synergy provided by applying what is known from forage digestibility and wheat and sorghum starch properties studies to the biofuels sector. Opportunities therefore, exist to improve biofuel qualities in these crops via genetics and agronomics. In contrast to cereal crops, switchgrass still retains tremendous exploitable genetic diversity, and can be specifically improved to Wt a particular agronomic, management, and conversion …

Dry Weight And Nitrogen Content Of Chickpea And Winter Wheat Grown In Pots For Three Rotations, James E. Bidlack, Charles T. Mackown, Srinivas C. Rao

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

Chickpea [Cicer arietinum (L.)] cultivars ‘ICCV-2’ and ‘Sarah’ were studied along with a control, multistrain, TAL 1148, and TAL 480 Bradyrhizobium strains to determine the effect(s) of cultivar and inoculum on dry weight (DW) and nitrogen (N) content of the legume, as well as soil mineral N, DW, and N content of wheat [Triticum aestivum (L.) emend. Thell.] in a continuous wheat-legume rotation. Chickpeas were planted during the summer and harvested in the fall of 1992, 1993, and 1994. Vegetative growth from chickpeas was incorporated into the soil prior to wheat planting, and soil cores were taken at …

Evidence Of Varietal Adaptation To Organic Farming Systems, Kevin M. Murphy, Kimberly A. Garland-Campbell, Steven R. Lyon, Stephen S. Jones

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

Consumer demand regarding the impacts of conventional agriculture on the environment and human health have spurred the growth of organic farming systems; however, organic agriculture is often criticized as low-yielding and unable to produce enough food to supply the world’s population. Using wheat as a model crop species, we show that poorly adapted cultivars are partially responsible for the lower yields often found in organic farming systems when compared with conventional farming systems. Our results demonstrate that the highest yielding soft white winter wheat genotypes in conventional systems are not the highest yielding genotypes in organic systems. An analysis of …

Ec07-101 2007 Spring Seed Guide, Lenis Alton Nelson, Bruce Anderson, Robert N. Klein, Richard B. Ferguson, David D. Baltensperger, Charles A. Shapiro, Stevan Z. Knezevic, James Krall

University of Nebraska-Lincoln Extension: Historical Materials

This circular is a progress report of variety and hybrid performance tests conducted by the Agronomy/Horticulture Department, the Northeast, West Central and Panhandle Research and Extension Centers, the South Central Agricultural Laboratory as part of the University of Nebraska and University of Wyoming at Torrington. Conduct of experiments and publication of results is a joint effort of the Agricultural Research Division and the Cooperative Extension Service. The following pages include the results of our variety testing programs for many crop species throughtout the state. We hope you find this information useful as you make hybrid and variety decisions for next …

Ec05-883 Crop And Livestock Prices For Nebraska Producers, 1960-2005, Darrell R. Mark, Dillon Feuz, Brad Heinrichs

University of Nebraska-Lincoln Extension: Historical Materials

This report contains historical price data for the major crops and livestock commodities produced in Nebraska. Prices received by producers are reported for 1960-2005 for most of the commodities.

The data was compiled from Nebraska Agricultural Statistics Service and Agricultural Prices, National Agricultural Statistics Service, USDA; Oil Crops Situation and Outlook, Economic Research Service, USDA; Cotton and Wool Outlook, Economic Research Service, USDA; and Livestock and Grain Market News, Agricultural Marketing Service, USDA. Sources of prices for each commodity are indicated on the tables.

Ec05-130 Guide For Weed Management In Nebraska, Roch E. Gaussoin, Brady F. Kappler, Robert N. Klein, Stevan Z. Knezevic, Drew J. Lyon, Alex Martin, Fred Roeth, Gail A. Wicks, Robert G. Wilson, Robert A. Masters, Patrick J. Shea, Larry D. Schulze

University of Nebraska-Lincoln Extension: Historical Materials

One of the major thrusts of all University of Nebraska weed science faculty is the Guide for Weed Management in Nebraska. This guide is not just the work of one or two people, rather it is a joint effort of all the authors to produce a comprehensive, information-packed resource. Each weed science faculty member is responsible for particular sections of the guide. The process of reviewing the current content, checking labels and research data and updating the content can be an extensive process. Each year new herbicide active ingredients and trade names are introduced and figuring out what a herbicide …

Ec05-185 Grazing Winter Wheat In Nebraska, Tom Holman, Drew J. Lyon, David D. Baltensperger, Ivan G. Rush, Ray Weed

University of Nebraska-Lincoln Extension: Historical Materials

Grazing cattle on winter wheat, often prior to grain harvest, is common throughout the southern Great Plains. Grazing generates about $50 million in income for Texas wheat producers and reduces the risk of growing wheat by providing a substantial income source other than grain. Benefits can be realized by grazing prior to the primary environmental risk period for drought, heat stress, and hail, all of which frequently reduce grain yield while having limited impact on forage production. Cattle also are grazed on winter wheat fields in western Nebraska and the surrounding region. Typically in Nebraska, fall forage would be used …

Nf560 Wheat Disease Fact Sheet No. 2: Management Program For Foliar Leaf Spot Diseases Of Wheat, John E. Watkins

University of Nebraska-Lincoln Extension: Historical Materials

This NebFact addresses symptoms and management of foliar leaf spot diseases in wheat.

Foliar leaf spot diseases in wheat occur in spring and summer. Tan spot is characterized by small brown, oval lesions with tan centers early on. Later large tan blotches have a yellow halo. Septoria leaf blotch is characterized by tan irregularly shaped blotches with black specks and a yellow margin. Septoria leaf and glume blotch is characterized by brown irregularly shaped blotches on leaves, purple-brown lesions on glumes and black specks absent from lesions.

The disease can be managed through crop rotation and stubble management that leaves …

Nf04-614 Management Program For Powdery Mildew Of Wheat (Revised August 2005), John E. Watkins

University of Nebraska-Lincoln Extension: Historical Materials

This NebFact, Wheat Disease Fact Sheet No. 7, discusses the management program for powdery mildew of wheat. It covers the cause and occurrence, key symptoms, cultural management practices, fungicide treatment programs with a table listing the fungicdes registered for foliar diseases of wheat, and application.

Spring Wheat Leaf Appearance And Temperature: Extending The Paradigm?, Gregory S. Mcmaster, Wally Wilhelm, D. B. Palic, John R. Porter, P. D. Jamieson

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

Extensive research shows temperature to be the primary environmental factor controlling the phyllochron, or rate of leaf appearance, of wheat (Triticum aestivum L.). Experimental results suggest that soil temperature at crown depth, rather than air temperature above the canopy, would better predict wheat leaf appearance rates. To test this hypothesis, leaf appearance in spring wheat ('Nordic') was measured in a 2-year field experiment (Nunn clay loam soil; fine, smectitic, mesic Aridic, Argiustoll) with three planting dates and two soil temperature treatments. One temperature treatment (denoted +3C) consisted of heating the soil at crown depth to 3 °C above the …

Comparison Of Chlorophyll And Carotenoid Concentrations Among Russian Wheat Aphid (Homoptera: Aphididae)-Infested Wheat Isolines, Tiffany Heng-Moss, X. Ni, T. Macedo, John P. Markwell, Frederick P. Baxendale, S. S. Quisenberry, V. Tolmay

Department of Entomology: Faculty Publications

Russian wheat aphid, Diuraphis noxia (Mordvilko), feeding injury on ‘Betta’ wheat isolines with the Dn1 and Dn2 genes was compared by assessing chlorophyll and carotenoid concentrations, and aphid fecundity. The resistant Betta isolines (i.e., Betta-Dn1 and Betta-Dn2) supported similar numbers of aphids, but had significantly fewer than the susceptible Betta wheat, indicating these lines are resistant to aphid feeding. Diuraphis noxia feeding resulted in different responses in total chlorophyll and carotenoid concentrations among the Betta wheat isolines. The infested Betta-Dn2 plants had higher levels of chlorophylls and carotenoids in comparison with uninfested plants. In contrast, infested Betta-Dn1 plants had the …

Ec03-1889 Wheat Disease Profiles Ii, John E. Watkins, Robert M. Harveson, Loren J. Giesler, Jennifer L. Chaky

University of Nebraska-Lincoln Extension: Historical Materials

This two-page, 4-color extension circular cover the diseases and symptoms of wheat in Nebraska. The listed diseases include: loose smut, common bunt, stinking smut, erot, black point, take-all, cephalosporium stripe, black chaff, powdery mildew, high plains disease.