Agricultural Science Commons^™

Movements Of European Starlings Captured At A Winter Roost In Omaha, Nebraska, H. Jeffrey Homan, George M. Linz, Garrett W. Unrein, James R. Thiele, John M. Hobbs

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

European starlings (Sturnus vulgaris) were using downtown Omaha, Nebraska, as a winter roosting site. We used radio telemetry and leg streamers to track birds in this roost. Between late December 2005 and March 2006, we radio tagged 57 starlings and located them 432 times. We attached leg bands and colored leg streamers to over 1,300 starlings captured at trapping sites within 7 km (4 mi) of the downtown roost. These techniques yielded data on previously unknown sites where starlings gathered to forage, stage, and roost. The maximum distance that a marked bird was observed from the downtown roost …

Nutrient Uptake Of Maize Affected By Nitrogen And Potassium Fertility In A Humid Subtropical Environment, H. Arnold Bruns, M. Wayne Ebelhar

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

Nitrogen (N) and potassium (K) fertility management of maize (Zea mays L.) in the humid subtropical Mississippi Delta may differ from a temperate climate because of its use in rotation with cotton (Gossypium hirsutum L.), soil temperatures rarely falling to 0 °C, and heavy winter rains that facilitate nutrient losses. An experiment to determine the [N] (concentration = [ ]), phosphorus [P], [K], calcium [Ca], magnesium [Mg], iron [Fe], manganese [Mn], zinc [Zn], and copper [Cu] and their total contents plant^-1 of maize grown in rotation with cotton, using N fertility levels of (134, 179, 224, 269, …

Effect Of Foliar Applied Plant Elicitors On Microbial And Nematode Populations In The Root Zone Of Potato, H. P. Collins, D. A. Navare, E. Riga, F. J. Pierce

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

Systemic acquired resistance (SAR) is a process whereby a plant that successfully
resists a pathogen becomes highly resistant to subsequent infection not only by the original pathogen but also by a wide variety of pathogens. Most SAR research has focused on resistance in leaves, so much less is known about the effectiveness of foliar applications of SAR compounds in the protection of plant roots and associated microorganisms in soil. This study was conducted to determine if foliar SAR-inducing applications (BTH or harpin) negatively impact the potato root system beneficial rhizosphere microbial populations and activity or influence pathogenic nematode populations. Foliar …

Un-Ionized Ammonia Exposure In Nile Tilapia: Toxicity, Stress Response, And Susceptibility To Streptococcus Agalactiae, Joyce J. Evans, David J. Park, Gregg C. Brill, Phillip H. Klesius

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

A series of experiments were conducted to determine the toxicity, behavior, blood glucose stress response, and disease susceptibility in Nile tilapia Oreochromis niloticus following un-ionized ammonia (UIA) exposure. The acute toxicity of un-ionized ammonia to Nile tilapia was measured in a 96-h static test. The median lethal concentration (LC50) was 1.46 mg/L UIA at 24 and 48 h postexposure, 1.33 mg/ L at 72 h postexposure, and 0.98 mg/L at 96 h postexposure. No mortalities were noted in unexposed (0 mg/ L) control fish or fish exposed to 0.5 mg/L UIA. However, 93–100% mortalities were observed within 24 h among …

International Shipping Of Fumonisins From Maize Extracts On C18 Sorbent, R. T. Riley, O. A. Torres, E. Palencia

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

Fumonisins are mycotoxins found in maize. In developing countries, the resources required for analysis are often lacking, and the shipping of maize between countries can be difficult since the importation of plant materials requires permits/ inspection to prevent the entry of pests that frequently infest maize. A simple, safe and legal method for shipping maize extracts to the USA was needed to conduct a survey of fumonisins in Central America. The objective was to develop a method for isolating and shipping maize extracts for fumonisin analysis so as to facilitate a survey of fumonisin exposure. The results indicate that fumonisins …

Improvements In Channel Catfish Growth After Two Generations Of Selection And Comparison Of Performance Traits Among Channel Catfish, Blue Catfish, And Hybrid Catfish Fingerlings In An Aquarium Rack System, Brian C. Small

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

A 9-week growth study was conducted to compare the fingerling performance of two genetic groups of channel catfish Ictalurus punctatus (United States Department of Agriculture [USDA] 103 and USDA303) with that of blue catfish I. furcatus and their hybrid in an aquarium rack system. Fish of approximately 20 g were randomly selected from multifamily populations and acclimated to the aquarium rack system for 2 weeks prior to the start of the 9-week study. Differences in growth indices, feed and protein efficiency, nitrogen retention, whole-body proximate composition, and plasma cortisol levels were determined at the completion of the study. The USDA303 …

Restoration Of Spermatogenesis And Male Fertility By Transplantation Of Dispersed Testicular Cells In The Chicken, Pavel Trefil, Alena Micáková, Jitka Mucksová, Jiń Hejnar, Martin Poplstein, Murray R. Bakst, Jirí Kalina, Jean-Pierre Brillard

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

Transplantation of male germ cells into sterilized recipients has been widely used in mammals for conventional breeding and transgenesis purposes. This study presents a workable approach for germ cell transplantation between male chickens. Testicular cells from adult and prepubertal donors were dispersed and transplanted by injection directly into the testes of recipient males sterilized by repeated gamma irradiation. We describe the repopulation of the recipient seminiferous epithelium up to the production of heterologous sperm in about 50% of transplanted males. In comparison to males transplanted with testicular cell preparations from adult donors, in which the first ejaculates with sperm were …

Human Emanations And Related Natural Compounds That Inhibit Mosquito Host-Finding Abilities, Ulrich R. Bernier, Daniel Kline, Kenneth H. Posey

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

One mechanism by which the action of semiochemicals can be classified is based on the behavioral impact within or external to the species of interest. As such, one can classify a chemical as one of the following^2,3:

1. Pheromone, if it results in response between insects of the same species
2. Kairomone, if it results in response in another species that benefits the species receiving the chemical cue
3. Allomone, if it results in response in another species that benefits the species releasing the chemical cue

However, the distinctions can be more specific by classification of chemical cues …

Laboratory Evaluation Of Avian Odors For Mosquito (Diptera: Culicidae) Attraction, S. A. Allan, Ulrich R. Bernier, D. L. Kline

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

Attraction of Culex quinquefasciatus Say, Culex tarsalis Coquillett, Culex nigripalpus Theobald, and Aedes aegypti (L.) to avian and other host odors was investigated in a dual-port olfactometer. Although attraction to a human arm was high for Ae. aegypti (>80%) and low for all Culex spp. (<25%), all species responded similarly to a chicken (55.3-73.6%). Responses of Ae. aegypti, Cx. quinquefasciatus, and Cx. nigripalpus to feathers were low (<20%) but greater than to controls. There was no difference in attraction of Cx. tarsalis to feathers or controls. Responses to CO₂ (5 ml/min) were low for all species (<15%) except Cx. tarsalis, which were moderate (24.5%). When feathers were combined with CO2, the resulting attraction was additive or lower than responses …

Genetic And Hybridization Evidence Confirms That A Geographic Population Of Gonatocerus Morrilli (Hymenoptera: Mymaridae) From California Is A New Species: Egg Parasitoids Of The Glassy-Winged Sharpshooter Homalodisca Coagulata (Homoptera: Cicadellidae), Jesse H. De León, Walker A. Jones, Mamoudou Sétamou, David J. W. Morgan

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

We investigated the differentiation and reproductive isolation among different geographic populations of Gonatocerus morrilli, egg parasitoids of the glassy-winged sharpshooter (Homalodisca coagulata), to confirm previous observations that there may exist a cryptic species complex or a new species. Two mitochondrial genes [cytochrome oxidase subunits I (COI) and II (COII)] and the internal transcribed spacer region 2 (ITS2) of several individuals per population were sequenced. G. morrilli populations from Texas (TX), Florida (FL), California (CA), and an outgroup (G. ashmeadi) were analyzed. For comparison, a population from Argentina (G. annulicornis) morphologically similar to G. …

Early-Successional Plants Regulate Grassland Productivity And Species Composition: A Removal Experiment, H. Wayne Polley, Brian J. Wilsey, Justin D. Derner, Hyrum B. Johnson, Joaquin Sanabria

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

Grime’s (1998) ‘‘mass-ratio’’ hypothesis holds that ecosystem processes depend in the short term on functional properties of dominant plants and in the longer term on how resident species influence the recruitment of dominants. The latter of these effects may be especially important among early-successional species in disturbed ecosystems, but experimental tests are few. We removed two groups of early-successional species, an annual forb Gutierrezia dracunculoides (DC.) S. F. Blake and annual species (mostly grasses) that complete growth early in the growing season [early-season (ES) species], from a heavily-grazed grassland in central Texas, USA dominated by a C₄ perennial grass. …

Effect Of Various Photoperiods On Testicular Weight, Weekly Sperm Output And Plasma Levels Of Lh And Testosterone Over The Reproductive Season In Male Turkeys, Jérôme Noirault, Jean-Pierre Brillard, Murray R. Bakst

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

The effects of duration and variation in photoperiod on testis weight, testicular sperm production, semen output, and hormone status over the reproductive season in male turkeys were investigated. In Experiment 1, four groups of males raised from 17 to 23 wk of age under a constant short photoperiod were subjected to a constant short (Group 1: 7L:17D; Group 2: 10.5L:13.5D), constant long (Group 3: 14L:10D) or progressively increasing photoperiod (Group 4: 7L:17D to 14L:10D) up to 60 wk of age. In Experiment 2, four groups of males first raised as in Experiment 1 up to 23 wk of age were …

Registration Of ‘Hallam’ Wheat, P. Stephen Baenziger, B. Beecher, Robert A. Graybosch, D. D. Baltensperger, Lenis Alton Nelson, Y. Jin, J. E. Watkins, J. H. Hatchett, Ming-Shun Chen, Guihua Bai

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

‘Hallam’ (Reg. no. CV-983, PI 638790) is a hard red winter wheat (Triticum aestivum L.) cultivar developed cooperatively by the Nebraska Agricultural Experiment Station and the USDA-ARS and released in 2005 by the developing institutions. Hallam was released primarily for its superior adaptation to rainfed wheat production systems in eastern Nebraska. The name Hallam was chosen to honor Hallam, NE, a town and its people rebuilding after a tornado.

Hallam was selected from the cross ‘Brule’ (Schmidt et al., 1983)/‘Bennett’ (Schmidt et al., 1981)//‘Niobrara’ (Baenziger et al., 1996) that was made in 1992. The F₁ generation was grown in …

Suppression Of House Flies (Diptera: Muscidae) In Florida Poultry Houses By Sustained Releases Of Muscidifurax Raptorellus And Spalangia Cameroni (Hymenoptera: Pteromalidae), Christopher Geden, Jerome Hogsette

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

Weekly releases of Muscidifurax raptorellus Kogan and Legner and Spalangia cameroni Perkins were made for 12 wk after house cleanouts in Florida pullet houses in either spring/summer (May-August) or fall (September-December). Releases were made by weekly placement of 62,500 and 85,000 pupae parasitized by M. raptorellus and S. cameroni, respectively, which produced an average of 79,049 and 32,841 adult female parasitoids per week. House fly (Musca domestica L.) pupal mortality, as measured by sentinel pupae, was about twice as high in the release house (40.2%) as in the two control houses (21.5 and 21.8%) in the summer release. …

Prevention Of Mosquitoes (Diptera: Culicidae) And House Flies (Diptera: Muscidae) From Entering Simulated Aircraft With Commercial Air Curtain Units, David A. Carlson, Jerome Hogsette, Daniel Kline, Chris D. Geden, Robert Vandermeer

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

Commercially available air curtain units were used to create air barriers to prevent mosquitoes and house flies from entering a simulated aircraft doorway together with passengers. Two assemblies of simulated passenger bridge and aircraft were constructed, and airflow measurements were recorded to confirm airflow characteristics for several combinations of commercial units. Three mosquito species were selected for different host-seeking characteristics, and house flies were selected to represent a large, strong-flying insect. Batches of 20 or 200 insects of four species were released into the passenger bridge just before 25 persons passed through the assembly, then insects that entered the aircraft …

Book Review: Identification And Geographical Distribution Of The Mosquitoes Of North America, North Of Mexico, Daniel L. Kline

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

Although much of this edition is a verbatim rehash of the first edition (1980), some very important changes have been made to Darsie and Ward's book that make it a valuable resource. This book is the only book that incorporates many of the recent changes in nomenclature, new species listings, and updates of geographic distributions of North American mosquitoes. Twelve species have been added to the book since the first edition. Changes to the text were necessary because of new species (e.g. Aedes albopictus and Ochlerotatus japonicus japonicus) invading different parts of North America (Sprenger and Wuithiranyagool 1986, Peyton …

Wayne E. Sabbe Arkansas Soil Fertility Studies 2005, Nathan A. Slaton

Arkansas Agricultural Experiment Station Research Series

Rapid technological changes in crop management and production require that research efforts be presented in an expeditious manner. The contributions of soil fertility and fertilizers are major production factors in all Arkansas crops. The studies described within will allow producers to compare their practices with the university’s research efforts. Additionally, soil test data and fertilizer sales are presented to allow comparisons among years, crops, and other areas within Arkansas.