Agricultural Science Commons^™

Evaluation Of Ulv And Thermal Fog Mosquito Control Applications In Temperate And Desert Environments, Seth C. Britch, Kenneth J. Linthicum, Wayne W. Wynn, Todd W. Walker, Muhammad Farooq, Vincent L. Smith, Cathy A. Robinson, Branka B. Lothrop, Melissa Snelling, Arturo Gutierrez, Hugh D. Lothrop, Jerry D. Kerce, James J. Becnel, Ulrich R. Bernier, Julia W. Pridgeon

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

Ultra-low-volume (ULV) and thermal fog aerosol dispersals of pesticides have been used against mosquitoes and other insects for half a century. Although each spray technology has advantages and disadvantages, only 7 studies have been identified that directly compare their performance in the field. US military personnel currently operating in hot-arid environments are impacted by perpetual nuisance and disease vector insect problems, despite adulticide operations using modern pesticide-delivery equipment such as ULV. None of the identified comparative studies has looked at the relative feasibility and efficacy of ULV and thermal fog equipment against mosquitoes in hot-arid environments. In this study we …

Fluid Fertilizer’S Role In Sustaining Soils Used For Bio-Fuels Production, John L. Kovar, Douglas L. Karlen

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

The short- and long-term effects on soil nutrient cycling, physical properties, and biological activity of striving for higher grain yields and removing crop residues for bio-fuels production must be understood to provide more quantitative crop and soil management guidelines. This study focuses primarily on potassium (K) and sulfur (S) response by corn (Zea mays L.) grown for bio-energy feedstock production. Our objectives for 2009 were to evaluate (i) the performance of several S fertilizers, including liquid ammonium thiosulfate (12-0-0-26S), for corn grown in Iowa, and (ii) the use of surface or subsurface bands of N-P-K-S fluid fertilizers to optimize …

Fluid Fertilizer’S Role In Sustaining Soils Used For Bio-Fuels Production, John L. Kovar, Douglas L. Karlen

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

Fast pyrolysis is optimized for production of bio-oil. Product yields are typically ~65% bio-oil, 20% biochar, 15% syngas.

Project Objective

To investigate N, P, K, and S dynamics in a comprehensive residue removal, tillage, and nutrient management study

Project Treatments

*Residue removal: 0, 50%, 90%

*Tillage: chisel plow, no-till

*Nutrient management: conventional (30K plants/A), high input (44K plants/A)

•Bio-char: 0, 4.32 tons/A, 8.25 tons/A

•Cover crops: annual, perennial

2009 Soil Test Levels

2009 Nutrient Management

Field Measurements

•Stand counts

•Whole-plant samples at V6

•Ear-leaf samples at mid-silk

•Grain yield and moisture

•Stover yield and moisture

•Grain and stover nutrient content

Procedures For Publishing In Non-Usda Media (Outside Publishing)

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

This P&P is an update of a previous version dated March 10, 1998. This P&P outlines revised responsibilities of the ARS author, Research Leader (RL), and other ARS officials. The most salient features of the new P&P are that the manuscript approval authority and associated responsibilities are delegated to the RL. ARS Form 115 (ARS-115) is revised accordingly (see Exhibit 1). Among the essential RL responsibilities are to determine the need and method for manuscript peer review, approve the technical and interpretive content of the manuscript, notify upper management about manuscripts containing prominent issues, obtain proper clearance/approval from upper management …

U.S. Meat Animal Research Center Clay Center, Ne

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

Mission

Research Units

U.S. Meat Animal Research Center Animal Health Research Unit

U.S. Meat Animal Research Center Environmental Management Research Unit

U.S. Meat Animal Research Center Genetics & Breeding Research Unit

U.S. Meat Animal Research Center Meat Safety and Quality Research Unit

U.S. Meat Animal Research Center Nutrition Research Unit

U.S. Meat Animal Research Center Reproduction Research Unit

2000-2009 Population Growth In The Midwest: Urban And Rural Dimensions, Liesl Eathington

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

Iowa’s recent population growth patterns have echoed trends across the Midwest, where strong urbanization forces are in evidence. From 2000- 2009, Midwestern population growth has concentrated in and around metropolitan cities, while most rural areas have lost population.

Outside of metropolitan areas, counties with larger cities fared better than their less urbanized counterparts. Proximity to a metropolitan area also bolstered growth or mitigated losses in some nonmetro counties.

States within the region demonstrated some notable differences in their non-metropolitan growth patterns. Missouri and Wisconsin demonstrated more balanced growth across their metropolitan and non-metropolitan counties than other Midwestern states.

Individual state …

Classical Biological Control For The Protection Of Natural Ecosystems, R.G. Van Driesche, R I. Carruthers, T. Center, M.S. Hoddle, J. Hough-Goldstein, L. Morin, L. Smith, D.L. Wagner, B. Blossey, V. Brancatini, R. Casagrande, C.E. Causton, J.A. Coetzee, J. Cuda, J. Ding, S.V. Fowler, J. H. Frank, R. Fuester, J. A. Goolsby, M. Grodowitz, T.A. Heard, M.P. Hill, J.H. Hoffmann, J. Huber, M. Julien, M.T.K. Kairo, M. Kenis, P. Mason, J. Medal, R. Messing, R. Miller, A. Moore, P. Neuenschwander, R. Newman, H. Norambuena, W.A. Palmer, R. Pemberton, A. Perez-Panduro, P.D. Pratt, M. Rayamajhi, S. Salom, D. Sands, S. Schooler, M. Schwarzländer, A. Sheppard, R. Shaw, P.W. Tipping, R.D. Van Klinken

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

Of the 70 cases of classical biological control for the protection of nature found in our review, there were fewer projects against insect targets (21) than against invasive plants (49), in part, because many insect biological control projects were carried out against agricultural pests, while nearly all projects against plants targeted invasive plants in natural ecosystems. Of 21 insect projects, 81% (17) provided benefits to protection of biodiversity, while 48% (10) protected products harvested from natural systems, and 5% (1) preserved ecosystem services, with many projects contributing to more than one goal. In contrast, of the 49 projects against invasive …

Effects Of A New Waste-Processing By-Product On Soil And Vegetation At Fort Campbell, Tennessee, R. R. Busby, D. L. Gebhart, H. A. Torbert, J. O. Dawson, G. A. Bollero, K. N. Potter, D. R. Curtin

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

A garbage-processing technology has been developed that sterilizes and separates inorganic and organic components of municipal solid waste. A study was initiated to evaluate the uncomposted organic by-product of this process as a soil amendment for establishing native prairie grasses on disturbed Army training lands. The waste was incorporated into a silt loam soil at Fort Campbell Military Reservation in the central United States. The waste material was applied at rates of 0, 4.5, 9, 18, and 36 Mg ha^-1 and seeded with native prairie grasses to assess its effects on vegetation for two growing seasons, with an additional …

‘Food For Life’: Looking Beyond The Horizon, Charles A. Francis, John W. Doran

Department of Agronomy and Horticulture: Faculty Publications

Our real challenge appears to be anticipating what the major challenges and constraints will be to food production and distribution a decade or more into the future. This could be called ‘Beyond the Horizon’ thinking. Today there is little disagreement over the massive depletion on a global scale of two essential inputs to agriculture: fossil fuels and fresh water. We also recognize that phosphorus is found in concentrated form in only a few deposits in nature, and that agriculture is rapidly using this limited resource and dispersing it through harvested products and soil loss from fields in forms that make …

Structural And Functional Divergence Of A 1-Mb Duplicated Region In The Soybean (Glycine Max) Genome And Comparison To An Orthologous Region From Phaseolus Vulgaris, Jer-Young Lin, Robert M. Stupar, Christian Hans, D. L. Hyten, Scott A. Jackson

Department of Agronomy and Horticulture: Faculty Publications

Soybean (Glycine max) has undergone at least two rounds of polyploidization, resulting in a paleopolyploid genome that is a mosaic of homoeologous regions. To determine the structural and functional impact of these duplications, we sequenced two ~1-Mb homoeologous regions of soybean, Gm8 and Gm15, derived from the most recent ~13 million year duplication event and the orthologous region from common bean (Phaseolus vulgaris), Pv5. We observed inversions leading to major structural variation and a bias between the two chromosome segments as Gm15 experienced more gene movement (gene retention rate of 81% in Gm15 versus 91% in …

Increased Weed Diversity, Density And Above-Ground Biomass In Long-Term Organic Crop Rotations, Samuel E. Wortman, John L. Lindquist, Milton J. Haar, Charles A. Francis

Department of Agronomy and Horticulture: Faculty Publications

While weed management is consistently a top priority among farmers, there is also growing concern for the conservation of biodiversity. Maintaining diverse weed communities below bioeconomic thresholds may provide ecosystem services for the crop and the surrounding ecosystem. This study was conducted to determine if weed diversity, density and biomass differ within and among organic and conventional crop rotations. In 2007 and 2008, we sampled weed communities in four long-term crop rotations near Mead, Nebraska, United States using seedbank analyses (elutriation and greenhouse emergence) and above-ground biomass sampling. Two conventional crop rotations consisted of a corn (Zea mays) …

Century-Old Mystery Of Puccinia Striiformis Life History Solved With The Identification Of Berberis As An Alternate Host, Yue Jin, Les J. Szabo, Martin Carson

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

The life history of Puccinia striiformis remains a mystery because the alternate host has never been identified. Inoculation of grasses using aeciospores from naturally infected Berberis chinensis and B. koreana resulted in infection on Poa pratensis, producing uredinia typical of stripe rust caused by P. striiformis. Analyses using real-time polymerase chain reaction and DNA sequence confirmed the rust fungus as P. striiformis. Pycnia and aecia were produced on B. chinensis, B. holstii, B. koreana, and B. vulgaris after inoculation using germinating telia of P. striiformis f. sp. tritici. Wheat inoculated with aeciospores from B. chinensis resulted in …

Nutrient Accumulation And Photosynthesis In Glyphosate-Resistant Soybeans Is Reduced Under Glyphosate Use, Luiz Henrique Saes Zobiole, Rubem Silvério De Oliveira Jr., Robert John Kremer, Antonio Saraiva Muniz, Adilson De Oliveira Jr.

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

Global production of glyphosate-resistant (GR) soybean [Glycine max (L.) Merr.] continues to increase annually; however, there are no particular specific fertilizer recommendations for the transgenic varieties used in this system largely because reports of glyphosate effects on mineral nutrition of GR soybeans are lacking. Several metabolites or degradation products of glyphosate have been identified or postulated to cause undesirable effects on GR soybeans. In this work we used increasing glyphosate rates in different application on cv. ‘BRS 242 GR’ in order to evaluate photosynthetic parameters, macro- and micronutrient uptake and accumulation and shoot and root dry …

Russia’S Agricultural Imports: Will The High Growth Of The 2000s Continue?, William M. Leifert, Olga Liefert, Mathew Shane

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

Russia’s agricultural imports during the 2000s have grown substantially, from €7.4 billion in 2000 to €19.2 billion in 2007 (Figure 1). The import growth has made Russia the second largest agricultural importer among emerging market economies, after China. The main imports are meat, highly processed products, fruits and vegetables (Figure 2). Russia’s agricultural exports have also grown during this time, though from a much lower base in value terms (and with most of the increase coming just from grain).

Europe has benefited strongly from the rise in Russia’s agricultural imports. During this decade, Russia has been the EU’s second largest …

Thermal And Mechanical Properties Of Compression-Molded Pmdi-Reinforced Pcl/Gluten Composites, Abdellatif Mohamed, Victoria L. Finkenstadt, Sherald H. Gordon, Debra E. Palmquist

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

Many biopolymers and synthetic polymers composites were developed by different researchers for environmental protection and for cost reduction. One of these composites is polycaprolactone (PCL) and vital wheat gluten or wheat flour composites were prepared and compatibilized with polymeric diphenylmethane diisocyanate (pMDI) by blending and compression-molding. PCL/pMDI blend exhibited glass transition (T_g) at -67 °C (0.20 J/g/ °C) and vital gluten at 63 °C (0.45 J/g/ °C), whereas no T_g was recorded for wheat flour. Although T_g was unmistakable for either PCL or gluten, all composite exhibited one T_g, which is strong indication of …

Drivers Impacting The Adoption Of Sustainable Agricultural Management Practices And Production Systems Of The Northeast And Southeast United States, G. F. Sassenrath, J. M. Halloran, D. Archer, R. L. Raper, J. Hendrickson, P. Vadas, J. Hanson

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

Agricultural production responds to social, political, economic, environmental, and technological drivers that influence producers’ decisions and shape the individual systems through modification of management practices, crop and livestock mix, and marketing strategy. We use an interview and discussion approach with producer panels to examine production systems in the eastern United States and explore key drivers impacting their unique characteristics and development. The internal social driver that values the farming lifestyle is a principle factor that leads people to choose farming. Irrespective of location, farming is first and foremost a lifestyle choice. The choice of type of production system is partly …

Cloning, Expression, And Immunogenicity Of Flavobacterium Columnare Heat Shock Protein Dnaj, Oscar Olivares-Fuster, Jeffery S. Terhune, Craig A. Shoemaker, Covadonga R. Arias

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

The Flavobacterium columnare heat shock protein (HSP) gene dnaJ* was isolated, cloned, expressed, and used as an antigen in a recombinant vaccine strategy for channel catfish Ictalurus punctatus. The F. columnare dnaJ* sequence was obtained from genomovars I and II and showed intraspecies variability. Recombinant protein was expressed and purified from Escherichia coli cultures and injected intraperitoneally (12 lg of purified DnaJ/fish) into fingerling channel catfish. In addition, induced (expressing the recombinant DnaJ) and uninduced (no recombinant protein being produced) E. coli cultures were also used to immunize fish. At 28 d postimmunization, antibody response was evaluated and the …

Production Characteristics And Body Composition Of Juvenile Cobia Fed Three Different Commercial Diets In Recirculating Aquaculture Systems, Charles R. Weirich, Paul S. Wills, Richard M. Baptiste, Marty A. Riche

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

The effect of feeding three commercial diets on production characteristics and body composition of juvenile cobia Rachycentron canadum reared using recirculating aquaculture systems (RASs) was assessed in a 56-d growth trial. Juvenile cobia (mean weight ± SE, 29.2 ± 0.7 g) were stocked into three 8-m³ tanks in each of four RASs at an initial density of 1.2 kg/m³. After stocking, fish were fed one of three commercial diets: Hybrid Striped Bass diet (HSB; 44% protein, 12% lipid), Finfish Gold diet (GOLD; 42% protein, 16% lipid), or Marine Grower diet (MG; 50% protein, 15% lipid), all at …

Comparisons Of Sperm Storage Tubule Distribution And Number In 4 Strains Of Mature Broiler Breeders And In Turkey Hens Before And After The Onset Of Photostimulation, M. R. Bakst, A. M. Donoghue, D. E. Yoho, J. R. Moyle, S. M. Whipple, M. J. Camp, G. Q. Liu, R. K. Bramwell

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

The biological basis of sustained fertility in broiler and turkey hens is their capacity to store sperm in the oviductal sperm storage tubules (SST) located in the uterovaginal junction. The objectives of this study were to determine if the numbers of SST varied between 4 strains of broiler breeders and determine the number of SST in the turkey before (less than 9 d of photostimulation) and after (up to 22 d of photostimulation and laying) photostimulation. No statistical differences were observed in SST numbers in the 4 strains of broilers examined or in turkey hens before and after the onset …

Identification Of Protein Carbonyls In Serum Of The Fetal And Neonatal Pig, Thomas J. Caperna, Amy E. Shannon, Le Ann Blomberg, Wesley M. Garrett, Timothy G. Ramsay

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

Oxidation of serum proteins leads to non-reversible carbonyl formation which alters their function and is associated with stress-related disease processes. The primary objective of this study was to quantify and identify oxidized serum proteins in fetal and newborn piglets. Protein carbonyls were converted to hydrazones with dinitrophenyl hydrazine and quantified spectrophotometrically. For identification, serum protein carbonyls were derivatized with biotin hydrazide, separated by 2D PAGE and stained with FITCavidin. Biotin-labeled proteins were excised from gels and identified by mass spectrometry. At birth, carbonyls were determined to be ∼600 pmole/mg serum protein. Fetuses at 50 and 100 days of gestation had …

Volatiles Emitted From Eight Wound-Isolated Bacteria Differentially Attract Gravid Screwworms (Diptera: Calliphoridae) To Oviposit, M. F. Chaudhury, Steven R. Skoda, A. Sagel, J. B. Welch

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

Bovine blood inoculated with bacteria isolated from screwworm [Cochliomyia hominivorax (Coquerel) (Diptera: Calliphoridae)]-infested animal wounds was tested as an attractant for oviposition for gravid screwworms. Eight species of gram-negative coliform (Enterobacteriaceae) bacteria mixed with bovine blood singly or all species combined and incubated for various times produced volatiles that attracted gravid flies in a cage bioassay in varying numbers. In 15-min duration tests, volatiles from five species of bacteria (Klebsiella oxytoca, Proteus mirabilis, Proteus vulgaris, Providencia rettgeri, and Providencia stuartii) attracted more females than volatiles of the three species (Enterobacter cloacae, Enterobacter …

2010 Across-Breed Epd Table, Larry Kuehn, Mark Thallman

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

The table of adjustment factors to be used to estimate across-breed expected progeny differences (AB-EPDs) for eighteen breeds was presented at the Beef Improvement Federation Annual Meeting in Columbia, MO, on June 30 (see Table 1). Across-breed adjustment factors have been calculated for growth traits and maternal milk since 1993. Adjustment factors for carcass traits have been calculated since 2008; to be included, breeds must have carcass data in the U.S. Meat Animal Research Center (USMARC) database and report their carcass EPDs on an actual carcass basis using an age-adjusted endpoint. Bulls of different breeds can be compared on the …

Effects Of Prescribed Fire And Herbicide Application On Cattle Grazing And Herbage Production From Yellow Bluestem Pastures, S. A. Gunter, R. L. Gillen

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

Forage management practices influence the quantity and quality of forage available to grazing cattle. The objectives of this experiment were to determine the effects of prescribed fire or herbicides on the density of forbs, the production and nutritive value of the herbage, and the performance of beef steers grazing Yellow bluestem [Bothriochloa ischaemum (L.) Keng var. ischaemum (Hack.) Celarier and Harlan] pastures. The experiment was conducted in northwestern Oklahoma from 1998 through 2000, and the untreated pastures (control) were not burned or sprayed. The prescribed-fire treatment (PFT) occurred annually between March 27 and April 10. The herbicide treatment (HT) consisted …

A Comparison Of Cumulative-Germination Response Of Cheatgrass (Bromus Tectorum L.) And Five Perennial Bunchgrass Species To Simulated Field-Temperature Regimes, Stuart P. Hardegree, Corey A. Moffet, Bruce A. Roundy, Thomas A. Jones, Stephen J. Novak, Patrick E. Clark, Frederick B. Pierson, Gerald N. Flerchinger

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

Cheatgrass (Bromus tectorum L.) has come to dominate millions of hectares of rangeland in the Intermountain western United States. Previous studies have hypothesized that one mechanism conferring a competitive advantage to this species is the ability to germinate rapidly at low temperatures in the fall, winter and spring and, therefore, initiate growth and establishment more rapidly than more desirable perennial bunchgrass species. In this experiment, we developed thermal-germination-response models for multiple seedlots of cheatgrass and five perennial grass species. We conducted sensitivity analysis on potential-cumulative-germination response to a 38-year simulation of field-variable conditions of seedbed temperature and moisture. Cheatgrass …

Expression And Self-Assembly Of Virus-Like Particles From Two Genotypes Of Marine Vesiviruses And Development Of An Elisa For The Detection Of Antibodies, Shasta D. Mcclenahan, Karin Bok, Stanislav V. Sosnovtsev, John D. Neill, Kathy A. Burek, Kimberlee B. Beckmen, Alvin W. Smith, Kim Y. Green, Carlos H. Romero

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

Sequences encoding the major and minor capsid proteins (VP1 and VP2) from two marine vesivirus isolates (Steller sea lion viruses V810 and V1415) were engineered for expression of virus-like particles (VLPs) in the baculovirus system. The resulting VLPs were morphologically similar to native vesivirus virions. Purified VLPs were probed in immunoblots with pooled antisera specific for nine San Miguel sea lion virus (SMSV) types, and a predominant protein of approximately 60 kDa was detected. An enzyme linked immunosorbent assay (ELISA) for the detection of antibodies was developed in which the VLPs served as antigen. The VLPs were adsorbed to the …

Groundwater Nutrient Concentrations During Prairie Reconstruction On An Iowa Landscape, M.D. Tomer, K.E. Schilling, C.A. Cambardella, P. Jacobson, P. Drobney

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

One anticipated benefit of ecosystem restoration is water quality improvement. This study evaluated NO₃-N and phosphorus in subsurface waters during prairie establishment following decades of row-crop agriculture. A prairie seeding in late 2003 became established in 2006. Wells and suction cup samplers were monitored for NO₃-N and phosphorus. Nitrate-N varied with time and landscape position. Nondetectable NO₃-N concentrations became modal along ephemeral drainageways in 2006, when average concentrations in uplands first became <10mg NO₃-N L⁻¹. This decline continued and upland groundwater averaged near 2mg NO₃-N L⁻¹ after 2007. The …

Optimized Construction Of Microsatellite-Enriched Libraries, Natascha Techen, R. S. Arias, Neil C. Glynn, Zhiqiang Pan, Ikhlas A. Khan, Brian E. Scheffler

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

The construction of microsatellite-enriched libraries is an indispensable tool to search for molecular markers as complete genome sequences are still not available for the majority of species of interest. Numerous protocols are available in the literature for the construction of these libraries; however, sometimes their low efficiency or lack of optimization in the protocols can restrict their efficacy. We have designed and tested various adapters and ligation methods; we also tested oligo-repeat combinations and hybridization temperatures, and created libraries with this new protocol for four organisms: Ipomoea batatas (L.) Lam, Chionanthus retusus Lindley & Paxton, Rotylenchulus reniformis Linford & Olivera …

Genetic Improvement In Winter Wheat Yields In The Great Plains Of North America, 1959–2008, Robert A. Graybosch, C. James Peterson

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

Data from USDA-coordinated winter wheat (Triticum aestivum L.) regional performance nurseries collected over the time period 1959 to 2008 were used to estimate genetic gain (loss) in grain yield, grain volume weight, days to heading, and plant height in winter wheats adapted to the Great Plains of North America. In both the Southern Regional (SRPN) and Northern Regional Performance Nurseries (NRPN), linear regression revealed significant positive relationships between relative grain yields of advanced breeding lines and calendar year of the nursery trial. The estimated genetic gain in grain yield potential since 1959 was approximately 1.1% (of the control cultivar …

Novel Carboxamides As Potential Mosquito Repellents, Alan R. Katritzky, Zuoquan Wang, Svetoslav Slavov, Dimitar A. Dobchev, C. Dennis Hall, Maia Tsikolia, Ulrich R. Bernier, Natasha M. Elejalde, Gary G. Clark, Kenneth J. Linthicum

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

A model was developed using 167 carboxamide derivatives, from the United States Department of Agriculture archival database, that were tested as arthropod repellents over the past 60 yr. An artificial neural network employing CODESSA PRO descriptors was used to construct a quantitative structure-activity relationship model for prediction of novel mosquito repellents. By correlating the structure of these carboxamides with complete protection time, a measure of repellency based on duration, 34 carboxamides were predicted as candidate mosquito repellents. There were four additional compounds selected on the basis of their structural similarity to those predicted. The compounds were synthesized either by reaction …

Structure-Activity Relationships Of 33 Carboxamides As Toxicants Against Female Aedes Aegypti (Diptera: Culicidae), Julia Pridgeon, James J. Becnel, Ulrich R. Bernier, Gary G. Clark, Kenneth J. Linthicum

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

Aedes aegypti L. is the primary vector of dengue and yellow fever viruses, and use of aerosolized insecticides is one of the primary ways to control this medically important mosquito. However, few new insecticides have been developed for mosquito control in recent years. As a part of our effort to search for new insecticides to control mosquitoes, toxicities of 33 carboxamides were evaluated against female A. aegypti by topical application. This group included nine different categories of compounds, namely benzamides, phenyl-propenamides, propanamides, butanamides, butenamides, pentanamides, pentenamides, hexanamides, and hexenamides, that exhibited varying levels of toxicity against this mosquito species. The …