Digital Commons Network^™

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 …

Unrooted Stem Cutting Physiology; Water Use And Leaf Gas Exchange Of Severed Stem Cuttings, Peter Alem

All Theses

Stem cuttings are one of the most frequently used and successful methods of vegetative plant propagation. The understanding of unrooted cutting physiology, especially gas exchange and water flux, is crucial for successful propagation of healthy plants. Prior to root initiation, water uptake is limited and leafy stem cuttings are most vulnerable to wilting.
Experiments were carried out in the greenhouse with poinsettia cuttings to determine water uptake, photosynthesis, transpiration and stomatal conductance from the time of severing to rooting, including time spent in storage. Water uptake through the severed stem was investigated in the laboratory and growth chamber. Cutting gas …

‘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 …

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) …

Soil Water And Crop Growth Processes In A Farmer's Field, Susmitha Surendran Nambuthiri

University of Kentucky Doctoral Dissertations

The study was aimed to provide information on local biomass development during crop growth using ground based optical sensors and to incorporate the local crop status to a crop growth simulation model to improve understanding on inherent variability of crop field. The experiment was conducted in a farmer’s field located near Princeton in Caldwell County, Western Kentucky. Data collection on soil, crop and weather variables was carried out in the farm from 2006 December to 2008 October. During this period corn (Zea mays L.) and winter wheat (Triticum sp) were grown in the field. A 450 m …

Chromium, Copper, And Arsenic Concentration And Speciation In Soil Adjacent To Chromated Copper Arsenate (Cca) Treated Lumber Along A Topohydrosequence, Donald Roy Schwer Iii

University of Kentucky Master's Theses

Arsenic (As), Chromium (Cr), and Copper (Cu) are ubiquitous in soils as a result of anthropogenic and geogenic processes. The fate of As, Cr, and Cu in the environment is largely governed by their speciation, which is influenced by soil physiochemical properties. This study investigated the influence of soil physiochemical properties and landscape position on As, Cr, and Cu concentration and speciation in soils adjacent to Chromated Copper Arsenate (CCA) treated lumber fence posts. Concentration gradients showed elevated total As and Cu adjacent to the three fence posts, which decreased with increasing distance from the posts. In addition, As and …

An Inventory And Condition Survey Of The Western Australian Part Of The Nullarbor Region, Peter-Jon A. Waddell, A K. Gardner, P Hennig

Technical Bulletins

The inventory and condition survey of the Western Australian part of the Nullarbor region, undertaken by the Department of Agriculture and Food, Western Australia (DAFWA) between 2005 and 2007, describes and maps the natural resources of the region. This survey report provides a baseline record of the existence and condition of the area's natural resources, to assist with the planning and implementation of land management practices. The report identified and described the condition of soils, landforms, vegetation, habitat, ecosystems, and declared plants and animals. It also assessed the impact of pastoralism and made land management recommendations. The Nullarbor region has …

Joint Fire Science Program – Lake Mead National Recreation Area Revegetating Burned Arid Lands: Identifying Successful Native Species Using Trait And Competition Analysis: Quarterly Progress Report, Time Period: October 1 — December 31, 2009, Margaret N. Rees

Fire Science

• Article accepted for publication in Journal of Arid Environments.

• Recharged irrigation gel packs for outplanting and watered seed plots at Goodsprings site.

• Completed full year of seed granivory trials at Goodsprings site.

• Presented information on this Task Agreement to 4th International Fire Ecology and Management Congress.

• Maintained nursery plots and added installment of nitrogen treatment.

Remote Sensing To Detect The Movement Of Wheat Curl Mites Through The Spatial Spread Of Virus Symptoms, And Identification Of Thrips As Predators Of Wheat Curl Mites, Abby R. Stilwell

Department of Entomology: Dissertations, Theses, and Student Research

The wheat curl mite (WCM), Aceria tosichella Keifer, transmits three viruses to winter wheat: wheat streak mosaic virus, High Plains virus, and Triticum mosaic virus. This virus complex causes yellowing of the foliage and stunting of plants. WCMs disperse by wind, and an increased understanding of mite movement and subsequent virus spread is necessary in determining the risk of serious virus infections in winter wheat. These risk parameters will help growers make better decisions regarding WCM management. The objectives of this study were to evaluate the capabilities of remote sensing to identify virus infected plants and to establish the potential …

Heirloom And Hybrid Tomato Yield And Quality In Organic And Conventional Production Systems, Diana J. Edlin

Masters Theses & Specialist Projects

Due to the recent changes in the economy of Kentucky tobacco production, some producers are seeking an alternative crop that will provide similar economic gains to tobacco without needing more acreage. Tomatoes are an existing crop in Kentucky that have been declining in acreage over the last five years. There is evidence to suggest that, through niche and local marketing, tomatoes may be able to fill the void left by tobacco. However, there is concern among producers that they will lose yield and/or quality if they switch to one of these niche production systems or cultivars.

A two year study …

Discovering Metabolic Networks Of Bovine Fertilization, Erin Lynn Young

Undergraduate Honors Capstone Projects

At the time of fertilization, a dramatic change occurs in the oocyte that transforms this cell from a metaphase arrested state into a metabolically active and dynamic state. The view of the flow of biological processes within organisms has recently shifted from that of a linear path to a more complex network. Biological processes are no longer thought of in the simple terms of DNA to RNA, RNA to proteins, and proteins to final activity. It is now known that many biological processes involve interconnected networks and feedback loops in which DNA, RNA, proteins, and metabolites perform specific roles. We …

Patterns Of Bison Hair Use In Nests Of Tallgrass Prairie Birds, Bryan R. Coppedge

The Prairie Naturalist

I examined patterns of bison (Bison bison L.) hair use by passerine birds nesting in the Tallgrass Prairie Preserve, Osage County, Oklahoma, 2002-2004. I collected and dissected 103 nests of 15 species into their constituent components. Nests were predominately composed of herbaceous material such as grass stems and leaves. Woody material and mud were rarely used. Bison hair was the most prominent zoological material used in nests, with lesser amounts and occurrence of arthropod silk, snake skin, feathers, jack rabbit (Lepus californicus Oray) fur, and man-made materials such as cellophane and string. At least one nest of 13 …

Long Distance Molt Migration By A Giant Canada Goose From Eastern South Dakota, Bobby J. Anderson, Charles D. Dieter

The Prairie Naturalist

To reduce crop damage by resident giant Canada geese (Schaible et al. 2005), the South Dakota Department of Game, Fish and Parks (SDGFP) initiated a program to reduce goose nesting success in eastern South Dakota. One management tool used by SDGFP personnel was the destruction of giant Canada goose nests. When a giant Canada goose has its nest destroyed, they are known to initiate a molt migration (Mykut 2002, Luukkonen et aI. 2008). We attached Platform Transmitting Terminals (PTT; model ST -19) to document and describe molt migrations of giant Canada geese following nest destruction. We captured 3 adult nesting …

Monitoring Meadows With A Modified Robel Pole In The Northern Black Hills, South Dakota, Daniel W, Uresk, Daryl E. Mergen, Ted A. Benzon

The Prairie Naturalist

We used a modified Robel pole to measure vegetation for a study conducted in the northern Black Hills, South Dakota. Objectives were to determine the relationship between visual obstruction readings and clipped standing herbage, and develop guidelines for monitoring standing herbage. The relationship between visual obstruction readings and standing herbage was linear and regression coefficients were significant (P≤ 0.001). Herbage ranged from 140 to 3313 kg· ha-1 with a mean of 1386 kg· ha^-1 (SE = 320 kg· ha^-1) for 123 transects. Visual obstruction readings (VOR) ranged from 0.6 to 30.4 (number of 1.27 cm bands …

Detection And Measurement Of Water Stress In Vegetation Using Visible Spectrum Reflectance, Arthur Zygielbaum

Department of Geography: Dissertations, Theses, and Student Research

At any scale, from a single microbe to the planet that nurtures us, water defines our place in the universe. It provides the hydraulic forces needed to give plants structure, and the medium enabling photosynthesis, the basis for most life on Earth, to occur. Knowledge of plant water status is vital to understanding the state or condition of vegetation, information which is essential to disciplines as diverse as agriculture, geography, and climatology. Non-destructive and remote sensing of plant water status allows the gathering of such information across wide geographic extents and over long periods of time. Monitoring vegetation remotely requires …

The Malawi Project: From Conventional To Holistic Decision Making, Grace Wetmore

Animal Science

How the Cal Poly Malawi Appropriate Technologies Team, and other development groups, can use Holistic Management to aid developing countries in an effort towards a sustainable future.

Observations Of Badgers Preying On Black-Tailed Prairie Dogs, Daniel S. Licht

The Prairie Naturalist

American badgers (Taxidea taxus) often visit black-tailed prairie dog (Cynomys ludovicianus) colonies, most likely in search of prey (Lomolino and Smith 2004, Shaughnessy and Cifelli 2004). Badgers are well suited to hunting fossorial prey such as prairie dogs by excavating burrows and capturing individuals belowground (Lindzey 2003). However, the ecological literature is sparse regarding details of how badgers hunt and capture prairie dogs underground. Eads and Biggins (2008) documented three occurrences of a badger excavating prairie dogs. That badger (apparently the same individual) had a den within the prairie dog town where captures occurred. This note …

Mortality Of Cranes (Gruidae) Associated With Powerlines Over A Major Roost On The Platte River, Nebraska, Gregory D. Wright, Timothy J. Smith, Robert K. Murphy, Jeffery T. Runge, Robert R. Harms

The Prairie Naturalist

Two 69-kilovolt powerlines spanning the Platte River in south central Nebraska are suspected to cause substantial mortality to sandhill cranes (Grus canadensis) and pose a threat to endangered whooping cranes (G. americana) that roost overnight on the river during spring and fall migrations. Most studies of crane collisions with powerlines in the region have focused on counts of carcasses away from night roosts on the river and none have accounted for potential biases in detecting carcasses. We found 61 carcasses of sandhill cranes below over-river segments of the two powerlines during 4 March to 7 April …

Noteworthy Winter Prey Of Short-Eared Owls In Southern Texas: A Case Study, Damon Williford, Marc C. Woodin, Mary Kay Skoruppa

The Prairie Naturalist

The winter range of North American short-eared owls (Asio flammeus) encompasses much of the United States, including southern Texas, where it is a common winter resident (Oberholser 1974, Rappole and Blacklock 1985). Winter food habits of short-eared owls are relatively weJl documented, but the majority of investigations have been conducted in eastern Canada and northeastern U.S. (Clark 1975, Holt 1993); midwestern U.S. (Colvin and Spaulding 1983); and British Columbia and Pacific northwestern U.S. (Bogiatto et al. 2001). The short-eared owl has a narrow trophic niche, generally preying on small mammals, with voles (Microtus spp.) and deer mice …

Bed Site Selection Of Fawn Pronghorn In Custer State Park, South Dakota, Chad P. Lehman, Jamin D. Hartland, Barbara J. Keller, Joshua J. Millspaugh, Gary C. Brundige

The Prairie Naturalist

We evaluated pronghorn (Antilocapra americana) fawn bedding site characteristics on a prairie and ponderosa pine (Pinus ponderosa) landscape interface in Custer State Park, South Dakota. We radio-marked 16 adult female pronghorn and collected bed site information from their fawns during 2007~2008. We compared bed site selection with random sites (n = 74) during 2 periods; the early hiding phase when fawns were 1 ~28 days of age (n = 23 bed sites) and the later group phase when fawns were 29~60 days of age (n = 52 bed sites). During the hiding phase fawns selected dry …

A Partial Inventory Of Islands In North Dakota: Potential For Breeding Waterfowl Management, Michael L. Szymanski

The Prairie Naturalist

Islands can provide secure nesting habitat for ducks and other waterbirds, especially in agriculturally dominated landscapes. I inventoried natural and man-made islands in the portion of North Dakota covered by the Prairie Pothole Joint Venture (PPJV). I mapped 1,305 islands in this area; up to 46% of which could provide enhanced nest success with management (e.g., predator removal or establishment of brushy cover). Management of islands for breeding ducks may be an important method for achieving desired reproductive rates in the PP JV as substantial areas of perennial grass cover are lost from federal conservation programs, primarily the Conservation Reserve …

Biological Control Of Purple Loosestrife (Lythrum Salicaria): Factors Affecting Galerucella Pusilla And Galerucella Calmariensis Establishment In Tidal Areas, Lynda Kathryn Moore

Dissertations and Theses

Galerucella pusilla and G. calmariensis have provided successful biological control of purple loosestrife (Lythrum salicaria L.) in non-tidal areas but only marginal control in areas of tidal influence. While a previous study identified mechanical scour by tidal waters as the main cause of establishment failure, purple loosestrife stem density explained more than 80% of the variability in presence and absence of Galerucella at my study sites in the Columbia River Estuary. A logistic regression model using purple loosestrife stem density, elevation, and their interaction as predictors accurately predicted 92.5% of Galerucella presence or absence observations of a test data …

Can R&D Investment Offset The Negative Impact Of Climate Change On Agricultural Productivity?, Nazrul Islam, Ruhul A. Salim

Climate Science Published Reports

Productivity growth in agriculture helps maintain the nation's economic prosperity. However, long-run productivity growth in agriculture faces several challenges such as the potential worsening of climate due to global warming and the loss of productive land due to land use competition, salinity, wind erosion and soil acidity. Strategic policy making and appropriate funding for sustained productivity growth in agriculture is therefore crucial.

Research and development (R&D) to drive innovation is an acknowledged main source of productivity growth. The development and application of technologies generated through R&D boosts agriculture's productivity. Agricultural R&D activities in Australia and in most other developed economies …

Photo Highlights Of The 10th Kentucky Grazing Conference, Kentucky Grazing Conference

Kentucky Grazing Conference

No abstract provided.

Forage Spokesman Information, Tom Flowers, Vince Rawe, Caldwell Willig

Kentucky Grazing Conference

No abstract provided.

Animal Welfare--Animal Rights: Role Of Grazing, Roy Burris

Kentucky Grazing Conference

The care and handling of farm animals has drawn a lot of media attention lately. Some well-publicized events have given our industry the proverbial black-eye and led to a chain of events that has left livestock producers feeling very vulnerable to negative attacks. Although these events have been very isolated, they have had some very farreaching effects. Could they have been prevented? How? What do we do now?

Extended Grazing And Reduced Stored Feed, Edward N. Ballard

Kentucky Grazing Conference

Feed costs represent the major cost in most livestock production systems. A recently completed analysis of 225 Standardized Performance Analysis (SPA) Beef Cow Records on herds in Illinois and Iowa showed that feed cost was the overriding factor determining profitability, explaining over 57 percent of the herd-to-herd variation. Typically the cost of supplying nutrients to ruminant livestock is much greater using harvested feedstuffs as opposed to grazing pastures or crop residues. The primary function of a grassland farm is to convert solar energy to marketable livestock products in the most efficient manner. The fewer steps between the animal product and …

Stored Feed Needs: How Much? What Quality?, Jeff Lehmkuhler

Kentucky Grazing Conference

Feed resources are the largest variable expense in beef production systems outside the initial investment in the livestock. When we look at Standardized Performance Analysis (SPA) information from Texas and Minnesota, states that are at the extreme from an environment stance, the projected costs for maintaining a beef cow are strikingly similar. It is important to note that these costs include all expenses and opportunity costs. Getting back to the SPA information, in 2007 the annual cost to maintain a cow in Texas was determined to be roughly $590 while the Minnesota value was near $610 or only about $20/cow …

Tall Fescue Grazing Research, Glen Aiken

Kentucky Grazing Conference

‘Kentucky-31’ tall fescue, like it or hate it, covers 5 million acres of Kentucky and if you do not have it on your farm, it is likely that one of your bordering neighbors does! Tall fescue owes its persistence and productivity in large part to a fungal endophyte that infects most plants. This endophyte produces an array of alkaloids that benefit the plant in tolerating heat, drought, and grazing. Unfortunately, the endophyte also produces ergot alkaloids that can cause “fescue toxicosis” in cattle. Cattle inflicted with toxicosis have reduced dry matter intake, elevated body temperature, and often retain their winter …

Weed Control Options For Pastures, Jon Doran

Kentucky Grazing Conference

What is a weed? A pasture or hayfield “weed” is any plant that you deem as being out of place and/or a plant that is decreasing your desired forage production. Weeds may be classified in several ways including broadleaf weeds, woody plants, and undesirable grasses. Besides decreasing forage, weeds can also interfere with forage utilization, grazing distribution, etc. There are several methods available to control weeds and increase production of and access to desirable forages. The three main methods are cultural, mechanical, and chemical. The cultural method is quite simple-a thriving grass stand is an excellent form of weed control …