Agricultural Science Commons^™

Structural Attributes Of Schizachyrium Scoparium In Restored Texas Blackland Prairies, Justin D. Derner, H. Wayne Polley, Hyrum B. Johnson, Charles R. Tischler

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

Structural attributes of the C₄, perennial bunchgrass Schizachyrium scoparium in restored prairies may be affected by the time since restoration. One hundred plants each in 8-, 17-, and 23-year-old restored prairies and a native Texas Blackland prairie were assessed for the presence/absence and diameter of a hollow crown (i.e., dead center portion), degree of fragmentation, plant height, and tiller density.

Potential For Transport Of Boll Weevils (Coleoptera: Curculionidae) To The Cotton Gin Within Cotton Modules, Thomas W. Sappington, Alan D. Brashears, Megha N. Parajulee, Stanley C. Carroll, Mark D. Arnold, John W. Norman Jr., Allen E. Knutson

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

There is concern that cotton gins located in boll weevil, Anthonomus grandis grandis Boheman, eradication zones serving customers in adjacent infested zones may serve as a site for boll weevil reintroductions if weevils are transported alive inside cotton modules. We surveyed fields in three distinct areas of Texas and found that weevils can be present in large numbers in cotton fields that have been defoliated and desiccated in preparation for harvest, both as free adults and as immatures inside unopened bolls. Harvested cotton taken from module builders indicated that ∞100-3,700 adult boll weevils were packed inside modules constructed at the …

Escherichia Coli O157:H7 In The Gallbladders Of Experimentally Infected Calves, William C. Stoffregen, Joachim F. L. Pohlenz, Evelyn A. Dean-Nystrom

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

Fifteen weaned calves (age 89–141 days) were treated with dexamethasone (0.25 mg/kg, IV) for 3 days before, the day of, and the day after inoculation with 10 colony-forming units of either Escherichia coli O157:H7 (strain 86-24, which produces Shiga toxin 2 and intimin; n=13) or nonpathogenic E. coli (strain 123, which does not produce Shiga toxin or intimin; n=2). All calves were necropsied 4 days after inoculation. Histologic lesions of attaching and effacing bacteria were observed in the large intestine (12/13) and in the gallbladder mucosa (5/13) of calves inoculated with E. coli 86-24. Cholecystitis was present in 12 of …

Cytokinin-Induced Metabolic Redirection, Uyen Bao, Gautam Sarath

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

Cytokinins are key triggers for the growth and differentiation of plant cells. We have generated a transgenic line of Arabidopsis that carries a rice hemoglobin promoter fused to GUS. Earlier research has indicated that this promoter is very responsive to cytokinins. We are utilizing this line to understand the global and local responses of gene-expression to exogenously applied cytokinins. In addition, we have cloned and have started to characterize two gene products of as yet unknown functions that are dramatically up-regulated or down-regulated in response to cytokinins. Data from microarray analyses will be discussed in relation to potential metabolic redirection …

Determination Of Dimethylselenide And Dimethyldiselenide By Gas Chromatography–Photoionization Detection, William J. Hunter, L. David Kuykendall

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

A simple method for the determination of volatile selenium compounds employing a gas chromatograph equipped with a photoionization detector is described. The method involves the direct injection of dimethylselenide (DMS) or dimethyldiselenide (DMDS) into the gas chromatograph; no derivatization of the sample was required. The photoionization detector was capable of detecting 60 pg (0.55 pmol) of DMS and 150 pg (0.80 pmol) DMDS. Sensitivity was 10–50 times greater with DMS and 4–20 times greater with DMDS when the photoionization detector was employed than when the flame ionization detector was employed.

Detection And Characterization Of Amitraz Resistance In The Southern Cattle Tick, Boophilus Microplus (Acari: Ixodidae), Andrew Y. Li, Ronald B. Davey, Robert J. Miller, John E. George

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

Amitraz, a formamidine acaricide, plays an important role in the control of the southern cattle tick, Boophilus microplus (Canestrini), and other tick species that infest cattle, dogs, and wild animals. Although resistance to amitraz in B. microplus was previously reported in several countries, the actual measurement of the level of amitraz resistance in ticks has been difficult to determine due to the lack of a proper bioassay technique. We conducted a survey, by using a newly reported technique that was a modification of the standard Food and Agriculture Organization larval packet test, to measure the levels of resistance to amitraz …

Predicting Phenological Development In Winter Wheat, Qingwu Xue, Albert Weiss, P. Stephen Baenziger

Department of Agronomy and Horticulture: Faculty Publications

Accurate prediction of phenological development is important in the winter wheat Triticum aestivum agroecosystem. From a practical perspective, applications of pesticides and fertilizers are carried out at specific phenological stages. In crop-simulation modeling, the prediction of yield components (kernel number and kernel weight) and wheat-grain yield relies on accurate prediction of phenology. In this study, a nonlinear multiplicative model by Wang & Engel (WE) for predicting phenological development in differing winter wheat cultivars was evaluated using data from a 3 yr field experiment. In the vegetative phase (emergence to anthesis) the daily development rate (r) was simulated based on the …

Groundwater Trends In The Kent-Frankland Sub-Region, Arjen Ryder

Natural resources published reports

The South Coast Regional Initiative Planning Team (SCRIPT) has divided the South Coast region of Western Australia into six sub-regions. Kent-Frankland covers the catchments of the Frankland, Gordon and Kent' Rivers. Approximately two-thirds (450,000 ha) has been cleared for agriculture. This publication describes the groundwater trends, risk of shallow watertables, and technical feasibility of salinity management on agricultural land.

Soil-landscape zones are spatial units based on geology and geomorphology. Since most groundwater processes in WA are controlled by the geologic and regolith properties, these zones can be used for allocating hydrological attributes, such as groundwater characteristics and trends. The hydrological …