Agricultural Science Commons^™

Loss Of Phosphorus By Runoff For Agricultural Watersheds, M. A. Elrashidi, M. D. Mays, J. Harder, D. Schroeder, P. Brakhage, S. Peaslee, C. Seybold, C. Schaecher

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

The loss of nutrients in runoff from agricultural land is a major cause of poor surface water quality in the United State. Scientists (NRCS) developed a technique to estimate the impact of agricultural watersheds on natural water resources. The objectives of this study were to apply this technique on the Wagon Train (WT),watershed to predict (1) loss of water by surface runoff, (2) loss of phosphorus (P) from soils by runoff and P loading for WT reservoir. The annual loss of water by runoff was estimated at 4.32 million m³ . The USGS data for a 50-year period (1951 …

High-Throughput Immunoblotting Identifies Biotin-Dependent Signaling Proteins In Hepg2 Hepatocarcinoma Cells1, Rocio Rodriguez-Melendez, Jacob B. Griffin, Gautam Sarath, Janos Zempleni

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

Biotin affects the abundance of mRNA coding for ~10% of genes expressed in human-derived hepatocarcinoma (HepG2) cells. Here, we determined whether effects of biotin on gene expression are associated with changes in the abundance of distinct proteins in cell signaling and structure. HepG2 cells were cultured in media containing the following concentrations of biotin: 0.025 nmol/L (denoted “deficient”), 0.25 nmol/L (“physiological” = control), and 10 nmol/L (“pharmacological”) for 10 d before harvesting. The abundance of 1009 proteins from whole-cell extracts was quantified by using high-throughput immunoblots. The abundance of 44 proteins changed by at least 25% in biotin-deficient and biotin-supplemented …

Inactivation Of Enteric Adenovirus And Feline Calicivirus By Chlorine Dioxide, Jeanette A. Thurston-Enriquez, Charles N. Haas, Joseph Jacangelo, Charles P. Gerba

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

Chlorine dioxide (ClO₂) inactivation experiments were conducted with adenovirus type 40 (AD40) and feline calicivirus (FCV). Experiments were carried out in buffered, disinfectant demand-free water under high- and low-pH and -temperature conditions. Ct values (the concentration of ClO₂ multiplied by contact time with the virus) were calculated directly from bench-scale experiments and from application of the efficiency factor Hom (EFH) model. AD40 Ct ranges for 4-log inactivation (Ct_99.99%) at 5°C were >0.77 to 0.80 to 0.49 to Ct_99.99% ranges were observed for pH 6 and 8, respectively. FCV Ct_99.99% ranges for 5°C …

Plant Adaptation Regions: Ecological And Climatic Classification Of Plant Materials, Kenneth P. Vogel, Marty R. Schmer, Robert B. Mitchell

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

The effective use of plant materials for an array of objectives including conservation, restoration, renovation, landscaping, and bioremediation requires knowledge of the adaptation of each species and, more specifically, knowledge of the adaptation of cultivars, strains, accessions, or ecotypes of a species to specific sites or regions. For agronomic and horticultural plants, specific adaptation information has been and continues to be developed by extensive testing. Rangeland, grassland, park, and restoration project managers often lack the resources to determine adaptation areas for plant materials because of the large number of species that are used and the extensive geographical areas that are …

Dynamic Response Indicators Of Heat Stress In Shaded And Non-Shaded Feedlot Cattle, Part 2: Predictive Relationships, R. A. Eigenberg, T. M. Brown-Brandl, John A. Nienaber, G. Leroy Hahn

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

Summer heat provides stressful conditions for Bos taurus feeder cattle; in extreme instances these conditions can be fatal. One management option is to provide shade structures for feedlot animals. This study was conducted during the summer of 2001 to compare physiological responses of cattle with shade access or no-shade access. Eight steers were selected from a group of 12, and assigned individual pens. Four pens were fitted with shade structures that allowed the steers to choose shade; the remainder had no shade option. The animals were rotated through pen assignments during the summer season. Continuous measures of respiration rate and …

Big Bluestem Pasture In The Great Plains: An Alternative For Dryland Corn, Kenneth P. Vogel, Gary E. Varvel, Robert B. Mitchell, Terry J. Klopfenstein, Richard T. Clark, Bruce Anderson

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

Big bluestem pasture can earn more than twice as much per acre as dryland corn.

Corn production and perennial grass pastures provide the foundation for the agricultural industry in the central and eastern Great Plains. Typically, many producers grow both corn and perennial grass pastures to meet livestock feed demands and to diversify the operation. For example, corn was produced on more than 37% of the total cropland, and perennial pasture comprised 49% of the land in farms in Nebraska.1 Corn was produced on an average of 7.8 million acres in Nebraska from 2000 to 2002, with 40% being dryland …

Penicillin-Binding Proteins In The Pathogenic Intestinal Spirochete Brachyspira Pilosicoli, Rohana P. Dassanayake, Gautam Sarath, Gerald E. Duhamel

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

Penicillin-binding proteins (PBPs) of slightly different molecular masses (94, 62 or 68, 42 or 50, 25, and 22 kDa) were identified in one human and two porcine Brachyspira pilosicoli strains. Identification of PBPs of B. pilosicoli provides a basis for characterization of the genes encoding these proteins among pathogenic intestinal spirochetes of humans and animals.

Dynamic Response Indicators Of Heat Stress In Shaded And Non-Shaded Feedlot Cattle, Part 1: Analyses Of Indicators, T. M. Brown-Brandl, R. A. Eigenberg, J. A. Nienaber, G. Leroy Hahn

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

Heat stress in feedlot cattle can cause decreases in feed intake and growth, and in extreme cases may result in death. Providing shade during hot weather has shown inconsistent results, reducing direct and indirect losses in some areas of the United States, but not in others. The objectives of this study were to evaluate the dynamic responses of feedlot cattle to environmental conditions with and without access to shade, and to determine the most appropriate physiological measurement for monitoring feedlot cattle during hot weather as a guide for improved management. Eight crossbred steers (initially weighing 294.7±10.8 kg) were randomly assigned …

Soil Surveys: A Window To The Subsurface, Douglas A. Wysocki, P. J. Schoeneberger, H. E. Lagarry

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

Soils and underlying parent materials form a continuous system we must understand and manage in total. Numerous concerns (e.g., water quality, on-site waste disposal, landfill placement, and nutrient or pesticide movement) require an integrated knowledge and understanding of soil, the soil-to-substratum transition, and the deeper substratum. Soil C-horizons can exceed the thickness of the overlying A and B-horizons and contain unique morphological properties. The subsolum including C-horizons receives less descriptive emphasis than upper soil horizons. Soil scientists map and classify soils mainly on A and B-horizon properties. Soil forming and hydrologic processes that impart morphological features, however, extend considerably below …

Proceedings Of The 32nd Annual Meeting, Southern Soybean Disease Workers (March 2-3, 2005, Scottsdale, Arizona), Ray Schneider, Boyd Padgett, Michael Schmidt, Jason Bond, Stephen R. Koenning

Southern Soybean Disease Workers: Conference Proceedings

Contents

Southern Soybean Disease Workers 2004 treasury report

Southern United States Soybean Disease Loss Estimates for 2004. Compiled by SR Koenning

Initial Discovery of Asian Soybean Rust in Louisiana in 2004 and Lessons for 2005. RW Schneider, CA Hollier, and HK Wbitam

Efficacy of myclobutanil for control of Asian soybean rust in Brazil (2004). MT Iarnauti, NA Alvarenga, JA Rosseto, GR Tofoli, BD Olson, DG Ouimette, and DC Ruen.

Flutriafol - a triazole fungicide giving strong curative action and persistence of effect against Asian soybean rust. T Baker and R Noon Cherninova

Experience in Use of Syngenta Fungicides for Controlling …

Impact Of Reduced Lignin On Plant Fitness, J. F, Pedersen, K. P. Vogel, D. L. Funnell

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

Lignin content of crop plants has been reduced by traditional plant breeding, natural and induced mutations, and insertion of transgenes. The effects of these genes and associated lower lignin content have been examined in terms of agricultural fitness or with regard to economically harvestable yields of useful plant products, or, in the case of some perennial species, survivability over multiple years. In general, crop yields are depressed by significant reductions in lignin content. Other negative effects observed in plants with lowered lignin contents include lodging and reduction of long-term survival of some perennial species. However, the interactions of genes involved …

Silvopasture And Eastern Wild Turkey, Jim Robinson

Agroforestry Notes (USDA-NAC)

Trees and livestock account for much of the income production on lands throughout the southern United States. Today many landowners are combining these two operations into one system called silvopasture, where both timber and livestock are produced on the same field.

While economic gain is most often the primary goal of a silvopasture system, wildlife habitat enhancement is commonly seen as an added benefit. This Agroforestry Note discusses the habitat requirements of Eastern wild turkey with respect to management considerations for the production of timber and livestock forage within silvopasture systems.

Silvopasture systems typically are laid out by either planting …

Silvopasture Water And Fencing Systems For Cattle, Sid Brantly

Agroforestry Notes (USDA-NAC)

Silvopasture is an agroforestry system that combines grazing livestock with growing trees for a timber product. Creating small, fenced paddocks and rotating cattle builds in "recovery periods" for the forage and protects the soil and trees. In a silvopastoral system, grazing recovery periods can only be achieved when well-designed livestock water supplies and cross fences are used. Fortunately, technological advances in livestock water system design and fence materials have helped to create a feasible working environment where rotating livestock from one silvopasture paddock to another can be both convenient and affordable. However, some special considerations must be given to water …

Colonization Of Gnotobiotic Piglets By A Luxs Mutant Strain Of Escherichia Coli O157:H7, Dianna M. Jordan, Vanessa Sperandio, James B. Kaper, Evelyn A. Dean-Nystrom, Harley W. Moon

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

Gnotobiotic piglets inoculated with Escherichia coli O157:H7, its luxS mutant derivative, or nonpathogenic E. coli were evaluated for attaching and effacing lesions. Although no differences in clinical symptoms were seen between pigs inoculated with the parent and those inoculated with the luxS mutant, the luxS mutant-inoculated pigs had a lower frequency of attaching and effacing lesions in the spiral colon than parent strain-inoculated pigs.

Intsormil 2005 Annual Report, John M. Yohe, Kimberly Christiansen, Joan Frederick

INTSORMIL Impacts and Bulletins

The 2005 INTSORMIL Annual Report presents the progress and notable achievements by the SorghumiMillet CRSP during the period of July 1, 2004 - June 30, 2005. These results are an outcome of partnerships between scientists at six U.S. Land Grant Universities (Kansas State University, Mississippi State University, University of Nebraska, Purdue University, Texas A&M University and West Texas A&M University) and scientists of the Agricultural Research Service of the U.S. Department of Agriculture at Tifton, Georgia and National Agricultural Research Systems (NARS) and National Universities in nineteen countries in Central America, West Africa, East Africa and Southern Afflca.

Agricultural research …

Science-Based Organic Farming 2005: Toward Local And Secure Food Systems, Charles A. Francis, Twyla Hansen, Peter Skelton

Publications from the Center for Applied Rural Innovation (CARI)

Organic farming includes growing food and fiber — animals, agronomic crops, horticultural fruits and vegetables, related products — as one dynamic and rapidly evolving component of our complex U.S. food system. Even as more farmers are moving toward organic certification and participation in an environmentally sound and economically lucrative market, questions arise about the long-term social impacts and sustainability of a set of practices that has gone from a movement to an industry. Consolidations in the organic trade have brought multinational corporations to the table, as they have observed a grassroots activity that has grown by 20% per year for …

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

Seasonal Acceptance Of Fourwing Saltbush By Sheep When Crested Wheatgrass Is The Alternative, Christine W. Royer, R. D. Horrocks, Val J. Anderson, Stephen B. Monsen

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

Many sagebrush-grass ranges have been seeded to crested wheatgrass [Agropyron desertorum (Fischer ex Link) Shultes]. These ranges are generally nutritionally inadequate for sheep (Ovis aries L.), except for short grazing periods in the spring and fall. To increase production and diversity, particularly crude protein for late-season grazing, fourwing saltbush [Atriplex canescens (Pursch.) Nutt.] was planted in an existing stand of crested wheatgrass. Quantification of sheep forage preferences on these improved ranges aids in determining the length of the grazing season and the extent to which shrubs provide the supplemental nutrition required. This seasonal grazing study was conducted …

Herbivory Alters Resource Allocation And Compensation In The Invasive Tree Melaleuca Quinquenervia, P. D. Pratt, M. B. Rayamajhi, T. K. Van, T. D. Center, P. W. Tipping

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

The Australian native Melaleuca quinquenervia is highly invasive in the Florida Everglades, U.S.A., where it experiences limited competition or herbivory from native species, making it a likely candidate for compensation. The introduced biological control agent Oxyops vitiosa feeds exclusively on the seasonal flushes of developing foliage at branch apices, which represents ~ 15% of the total foliar biomass.

Plant Functional Group Diversity As A Mechanism For Invasion Resistance, Monica L. Pokorny, Roger L. Sheley, Catherine A. Zabinski, Richard E. Engel, Tony J. Svejcar, John J. Borkowski

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

A commonly cited mechanism for invasion resistance is more complete resource use by diverse plant assemblages with maximum niche complementarity. We investigated the invasion resistance of several plant functional groups against the nonindigenous forb Spotted knapweed (Centaurea maculosa). The study consisted of a factorial combination of seven functional group removals (groups singularly or in combination) and two C. maculosa treatments (addition vs. no addition) applied in a randomized complete block design replicated four times at each of two sites.

Phosphorus Dynamics In Broiler Litter-Amended Soils, A. Adeli, K. R. Sistani, M. F. Bal'a, D. E. Rowe

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

Because land application of broiler litter is commonly made in the spring before cropping season and in the fall, it is essential to understand how environmental variations, such as temperature, affect the phosphorus (P) dynamics. A laboratory incubation study was conducted at Waste Management and Forage Research Unit, USDAARS with the objective of determining the effects of temperature and soil properties on water-soluble P (WSP), Mehlich 3 P, and P fractions in broiler litter-amended soils. Broiler litter was mixed with three soils (Leeper silty clay, Grenada silt loam, and Ruston sandy loam) at the rate of 10 Mg ha^{-1 …}

Molecular Evolution Of Herbicide Resistance To Phytoene Desaturase Inhibitors In Hydrilla Verticillata And Its Potential Use To Generate Herbicide-Resistant Crops, R. S. Arias, Michael D. Netherland, Brian E. Scheffler, Atul Puri, Franck E. Dayan

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

Hydrilla [Hydrilla verticillata (Lf) Royle] is one of the most serious invasive aquatic weed problems in the USA. This plant possesses numerous mechanisms of vegetative reproduction that enable it to spread very rapidly. Management of this weed has been achieved by the systemic treatment of water bodies with the herbicide fluridone. At least three dioecious fluridone-resistant biotypes of hydrilla with two- to fivefold higher resistance to the herbicide than the wild-type have been identified. Resistance is the result of one of three independent somatic mutations at the arginine 304 codon of the gene encoding phytoene desaturase, the molecular target …

Registration Of ‘Arrowsmith’ Hard White Winter Wheat, Robert A. Graybosch, C.J. Peterson, P. Stephen Baenziger, Lenis Alton Nelson, B.B. Beecher, D. D. Baltensperger, J.M. Krall

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

‘Arrowsmith’ (Reg. no. CV-969, PI 633911) hard white winter wheat (Triticum aestivum L.) was developed cooperatively by USDA-ARS, the Nebraska Agricultural Experiment Station, and the Wyoming Agricultural Experiment Station. Arrowsmith is adapted to dryland environments in western Nebraska and eastern Wyoming. It was released on the basis of its white grain color, medium-long coleoptile length, and tall plant height, all desirable features for wheat grown on dryland sites in the Nebraska Panhandle and eastern Wyoming.

Arrowsmith was derived from the cross KS87809-10/‘Arapahoe’, made in 1993. KS87809-10 is an experimental hard winter wheat from Kansas State University with the pedigree …

Effect Of Oxygen Management On Culture Performance Of Channel Catfish In Earthen Ponds, Eugene L. Torrans

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

Aeration allows for higher feeding rates and increased production of channel catfish Ictalurus punctatus in intensive and semi-intensive aquaculture systems. However, the effect of specific dissolved oxygen (DO) concentrations on various production parameters remains unknown. The purpose of this 2-year study was to determine the effect of daily minimum DO concentration on channel catfish production. Six 0.1-ha ponds were each equipped with three 0.37-kW (0.5-hp) aerators and one 0.37-kW circulator. Dissolved oxygen concentrations were monitored and recorded with a commercial oxygen monitor that also controlled aeration. During both years, aeration in the high-oxygen treatment was initiated when the DO concentration …

Abundance Of Plodia Interpunctella (Hubner) And Cadra Cautella (Walker) Infesting Maize Stored On South Carolina Farms: Seasonal And Non-Seasonal Variation, Richard T. Arbogast, Shahpar R. Chini

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

Seasonal trends and short-term fluctuations in abundance of Plodia interpunctella (Hubner) and Cadra cautella (Walker) infesting maize stored on two South Carolina farms were studied during three storage seasons (September 1990–June 1993). Coils of corrugated paper placed on the grain surface were used to trap mature larvae seeking pupation sites. Temperatures in the grain (18-cm-deep) and in the bin headspace were recorded hourly, and grain moisture content was measured weekly. Weekly mean numbers of moth larvae, and adults of two natural enemies, trapped in the coils were used for tracking changes in their abundance over time. The most significant findings …

Cryptic Plasmid Psku146 From The Wall-Less Plant Pathogen Spiroplasma Kunkelii Encodes An Adhesin And Components Of A Type Iv Translocation-Related Conjugation System, Robert E. Davis, Ellen L. Dally, Rasa Jomantiene, Yan Zhao, Bruce Roe, Shaoping Lin, Jonathan Shao

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

A cryptic plasmid of the wall-less plant pathogenic mollicute, Spiroplasma kunkelii CR2-3X, was cloned and its sequence analyzed. The 14,615 bp plasmid, designated pSKU146, has a nucleotide content of 28 mol% G + C, and contains 18 potential protein-coding regions (open reading frames, ORFs), of which six encode proteins that exhibit similarity to virulence-associated proteins involved in cell-to-cell adhesion or conjugal DNA transfer. One ORF encodes a 96 kDa protein, SkARP1, that is highly similar to SARP1 adhesin involved in attachment of Spiroplasma citri to insect vector gut membrane. Five ORFs encode proteins similar to TraE and Mob in walled …

Carbaryl Resistance In Mexican Strains Of The Southern Cattle Tick (Acari: Ixodidae), Andrew Y. Li, Ronald B. Davey, John E. George

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

Susceptibility to carbaryl in six Mexican strains of the southern cattle tick, Boophilus microplus (Canestrini), was evaluated with the Food and Agricultural Organization larval packet test. Tick strains from the cattle fever tick quarantine zone in Texas were more susceptible to carbaryl than to coumaphos or diazinon. Compared with the susceptible reference (Gonzalez) strain, Mexican tick strains demonstrated 10.9Ð59.5-fold resistance to carbaryl. SigniÞcant cross-resistance was found between carbaryl and the organophosphate acaricides coumaphos and diazinon. Bioassay results with synergists suggested that metabolic detoxification mechanisms did not play a major role in carbaryl resistance. Resistance to carbaryl was likely conferred by …

Insect Transmission Of Plant Pathogens, Rodrigo P. P. Almeida, Astri Wayadande, Todd Shelly

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

Much of biological research conducted today is multidisciplinary, partly because of the availability of ever simpler to use molecular tools and the realization that ecological systems are complex and multitrophic. Although there is a general trend toward academic specialization and cooperation, some fields still require that scientists be aware of the “bigger picture.” We consider that the study of insect-transmitted plant pathogens is one of those fields, where insect, pathogen, and plant are inseparably linked. In this triangle of interactions, researchers focus their interests on questions at the molecular and cellular to epidemiological levels. Throughout the years, plant vector entomologists …

Maintenance Of A Narrow Host Range By Oxyops Vitiosa; A Biological Control Agent Of Melaleuca Quinquenervia, G. S. Wheeler

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

Host range expansion in insect herbivores is often thought to be mediated by several factors, principal among them are secondary plant metabolites. In weed biological control, the host range of a prospective agent is one of the most important considerations in its implementation. Extensive host testing tests seek to determine the behavioral acceptance and nutritional value of different test plant species to the potential agent. A list of test plants is compiled that comprises species that are close taxonomic relatives of the target weed plus other species of economic or ecologic importance. The host testing of the Melaleuca quinquenervia biological …

Postweaning Performance Of Hair And Wool Sheep And Reciprocal-Crosses On Pasture And In Feedlot, M. A. Brown, H. S. Mayeux

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

Lambs from three diallel-mating plans (Dorset-St. Croix, n=140; Rambouillet-Gulf Coast, n=80; Katahdin-Suffolk, n=78) and a terminal-cross mating plan (Suffolk rams mated to Dorset, St. Croix and reciprocal-cross ewes, n=100) were used to evaluate postweaning grazing performance of traditional meat breeds and tropically adapted breeds of sheep.