Digital Commons Network^™

An Innovative Soil Test For Predicting Nitrogen Mineralization, F. M. Hons, R. L. Haney, A J. Franzluebbers

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

A routine soil testing procedure for soil N mineralization is needed that is rapid and precise. Not accounting for N mineralization can result in over application of N, especially in soils with a history of manure application. Our objectives were to compare results from a recently proposed rapid lab procedure with i) long-term N mineralization under standard laboratory conditions, ii) actual forage N uptake from soil receiving dairy cattle (Bas taurus) manure in a two-year field study and iii) yields of various crops throughout Texas and Oklahoma. The rapid procedure is based on the quantity of CO_{2 …}

Soil Carbon, Nitrogen Use, And Water Use Affected By Rotation In The Northern Corn Belt, Joseph L. Pikul Jr., Thomas E. Schumacher, Merle Vigil, Walter E. Riedell

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

Diversified crop rotation may improve production efficiency, reduce fertilizer nitrogen (N) requirements for com (Zea mays L.) and increase soil carbon (C) storage. Objectives were to determine effect of rotation and fertilizer N on soil C sequestration, water use, and N use. An experiment was started in 1990 on a Barnes clay loam (fine-loamy, mixed, superactive, frigid Calcic Hapludoll) near Brookings, South Dakota. Primary tillage on all rotations was with a chisel plow. Rotations were continuous com (CC), com-soybean [Glycine max (L.) Merr.] (CS) and a 4-year rotation of corn-soybean-wheat (Triticum aestivum L.) companion seeded with alfalfa …

Stomatal Acclimation Over A Subambient To Elevated Co2 Gradient In A C3/C4 Grassland, H. Maherali, C. D. Reid, H. W. Polley, H. B. Johnson, R. B. Jackson

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

An investigation to determine whether stomatal acclimation to [CO₂] occurred in C₃/C₄ grassland plants grown across a range of [CO₂] (200–550 μmol mol⁻¹) in the field was carried out.

Woody Invasion Of Grasslands: Evidence That Co2 Enrichment Indirectly Promotes Establishment Of Prosopis Glandulosa, H. Wayne Polley, Hyrum B. Johnson, Charles R. Tischler

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

Grasslands worldwide have been invaded by woody species during the last 200 years. Atmospheric CO₂ enrichment may indirectly have facilitated invasion by reducing soil water depletion by grasses.

Soil Health And Global Sustainability: Translating Science Into Practice, John W. Doran

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

Interest in the quality and health of soil has been stimulated by recent awareness that soil is vital to both production of food and fiber and global ecosystems function. Soil health, or quality, can be broadly defined as the capacity of a living soil to function, within natural or managed ecosystem boundaries, to sustain plant and animal productivity, maintain or enhance water and air quality, and promote plant and animal health. Soil quality and health change over time due to natural events or human impacts. They are enhanced by management and land-use decisions that weigh the multiple functions of soil …

Soil Health As An Indicator Of Sustainable Management, John W. Doran, Stamatis Stamatiadis, John Haberern

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

Population growth, a widening gap between the rich and poor, environmental degradation, and a re-evaluation of energy use and alternatives will shape life in the 21st century. We will be challenged to increase food supplies for a global population one-and-a-half to two times its current size. But as agricultural systems grow to meet the demands of more people, increased pressure will be placed on our natural resources: competition for land, water and energy resources from both urban and industrial sectors becomes more acute and the available land base remains static or shrinks. Under current practices increased food production will greatly …

Impact Of Egg Storage On Embryo Development, M. R. Bakst, V. Akuffo

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

1. New information is introduced and other information reviewed regarding the impact of egg storage on the integrity of the avian embryo.

2. Morphologically, the blastoderm from an egg which has been stored more than 10 days is often asymmetrical and may have an attenuated appearance.

3. Fresh egg breakouts coupled with the perivitelline layer sperm-hole determination procedure provide detailed information on the male's contribution to overall fertility.

4. The biological basis for embryonic mortality in eggs stored for longer than 10 days remains the subject of speculation.

Recycled Paper Products As Substitutes For Gelling Agent In Screwworm (Diptera: Calliphoridae) Larval Diet, M. F. Chaudhury, L. Alfredo Alvarez, L. Lopez Velazquez

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

Absorbent recycled paper products were tested and compared with a sodium polyacrylate gelling agent, Aquatain, for solidifying larval diets of the screwworm, Cochliomyia hominivorax (Coquerel). A recycled newsprint product, Terra-Mulch, when mixed with water and dietary ingredients produced a diet medium of homogeneous texture that supported larval growth and development comparable to the standard diet prepared with the gelling agent. Biological yields as calculated from number of pupae per tray from both the diets were similar. Three other types of recycled paper products were tested. Although less homogeneous in texture, these diets were as good as the diet with Terra-Mulch. …

Two New Alchemilla L. (Rosaceae) Records For The Flora Of Turkey, Sema Hayirlioğlu Ayaz, Osman Beyazoğlu

Turkish Journal of Botany

Two Alchemilla L. (Rosaceae) species from north-east Anatolia are described as new records for Turkey.

Biomass And Nitrogen Traits Of Summer Pigeon Peas And Winter Wheat Grown For Three Rotations In Containers, Srinivas C. Rao, Charles T. Mackown, James E. Bidlack

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

Pigeon pea [Cajanus cajan (L.) Millsp.] cultivars, ‘Georgia-1’ and ‘ICPL-87’, were grown without inoculation and with Bradyrhizobium inoculation (multistrain, TAL 1127, or TAL 1132) to evaluate legume dry weight (DW) and nitrogen (N) content, soil mineral N, and subsequent wheat (Triticum aestivum L.) productivity. Pigeon peas were grown during summer and ‘TAM 101’ wheat was grown during winter, along with summer fallow controls fertilized with 0, 45, and 90 kg N ha^-1, in 36-cm diam. 20-L pots from 1992 to 1995. Representative pigeon peas were harvested in the fall and remaining plants were incorporated into the …

Bollworm (Lepidoptera: Noctuidae) Ecology On Genetically Engineered Bollgard And Bollgard Ii Cottons, Jeffrey Gore

LSU Doctoral Dissertations

The ecology of bollworms, Helicoverpa zea (Boddie), on Bollgard and Bollgard II cottons, Gossypium hirsutum L., was studied in field and laboratory experiments. Neonate bollworm larvae were placed on selected components of cotton squares and flowers from non-Bollgard, Bollgard, and Bollgard II cotton varieties. Larval survival was higher on flower anthers and square anthers than on other floral parts for each cultivar. Bollworm survival was lowest on all Bollgard II floral structures. To evaluate larval behavior on Bollgard cotton, first instar bollworms were placed on terminals of non-flowering and flowering cotton plants. Larvae were recovered lower on Bollgard cotton than …

Extraction Of Silymarin Compounds From Milk Thistle (Silybum Marianum) Seed Using Hot, Liquid Water As The Solvent, J. F. Alvarez Barreto, D. Julie Carrier, E. C. Clausen

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

High-value specialty chemicals are usually obtained from natural products by extracting with generally regarded as safe (GRAS) solvents. Because organic solvents are quite often used, high operating and disposal costs occur. When compared to traditional solvents, water is an interesting alternative because of its low operating and disposal costs. Milk thistle contains compounds (taxifolin, silychristin, silydianin, silybinin A, and silybinin B) that display hepatoxic protection properties. This paper examines the batch extraction of silymarin compounds from milk thistle seed meal in 50°C, 70°C, 85°C and 100°C water as a function of time. For taxifolin, silychristin, silybinin A, and silybinin B, …

Identifying Safety Strategies For On-Farm Grain Bins Using Risk Analysis, Raymond S. Avery, Dylan P. Carpenter, Thomas A. Costello

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

The potential for grain bin accidents exists each year on Arkansas farms and farms across the nation. The trend toward increasing utilization of on-farm grain drying and storage could lead to an increase in grain bin accidents. The sharp contrast between a safe, efficient operation and one that leads to injury or death can be represented as sets of farmer-decisions and subsequent chance events. A model was constructed to define the risk associated with grain bin entry and in-bin activity so that safety interventions could be identified and implemented to reduce the probability of injury and death. A survey was …

Discovery: The Student Journal Of Dale Bumpers College Of Agricultural, Food And Life Sciences - Volume 3 2002, Several Authors

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

No abstract provided.

Instructions For Authors, Discovery Editors

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

No abstract provided.

Expression Patterns Of Novel Wound-Inducible Plant Genes In Medicago Truncatula, Mandy M. Cox, Kenneth L. Korth

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

Terpenoids are an important class of defensive compounds that can accumulate in plants after pathogen infection or injury by chewing insects. Clones encoding putative terpene synthases and an oxidosqualene synthase, isolated from insect-damaged Medicagotruncatula leaves, were selected from an expressed sequence tag (EST) database. The cDNA clones were used as radiolabeled probes to analyze gene expression in leaves treated by known factors that can trigger a defense response in plants. Transcript levels for all of the genes examined increased in response to artificial wounding, insect herbivory, and methyl jasmonate (meJA) treatments, whereas salicylic acid (SA) and glucose oxidase (GOX) had …

Bradyrhizobium Japonicum And Soybean Symbiotic Response To Glyphosate In Glyphosate-Tolerant Soybeans, Jodie M. Scheele, C. Andy King, Marilynn K. Davies, Larry C. Purcell

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

Soybean (Glycine max) grain contains approximately 40% protein and 6.5% nitrogen (N) on an elemental basis. Therefore, the plant requires an abundant N supply throughout its life cycle, and symbiotic N fixation of soybean with Bradyrhizobium japonicum provides 40 to 85% of the soybean N. Although soybean cultivars have been genetically engineered to withstand the herbicide glyphosate, B. japonicum grown in culture is sensitive to glyphosate. We hypothesized that glyphosate applied to glyphosate-tolerant soybean would inhibit nodulation by B. japonicum unless B. japonicum could also be selected for glyphosate tolerance. Cultures of B. japonicum were challenged with sublethal doses of …

Declared Plant Control Handbook Recommendations For The Control Of Declared Plants In Western Australia, John R. Peirce, Rachael A. Pratt

Biosecurity published reports

Sixth Edition.

Reviewed October 2005.

Plants may be "declared" by the Agriculture Protection Board under the Agriculture and Related Resources Protection Act 1976.If a plant is declared, all landholders are obliged to control that plant on their properties. Declarations specifies a category, or categories, for each plant according to the control strategies or objectives which the Agriculture Protection Board believes are appropriate in a particular place.

Among the factors considered in categorising declared plants are:

* the impact of the plant on individuals, agricultural production and the community in general,

* whether it is already established in the area, and …

Genetic Variability Studies In A Selected Population Of Azadirachta Excelsa (Sentang) With Aflp Marker Technology, Chiew Foan Chin

Student Works (2000-2009)

A maternal half-s/b population of Azadirachta excelsa was established from seeds in a randomised complete block design with three replicates. 100 to 200 seeds were collected from each of the 13 selected mother trees. The mother trees were categorised into three groups i.e. large, medium and small according to their girth sizes. 50 progeny seedlings from each scedlot per replicate were planted in the experimental field. Genetic studies on phenotypic measurements and molecular marker analysis were carried out on the established A. excelsa population. Measurements of quantitative traits including diameter breast height (Dbh) and total height were made. Mean Dbh …

Effect Of Tillage And Herbicide Treatments On Redvine (Brunnichia Ovata) Subterranean Morphology, E. C. Gordon, T. C. Keisling, L. R. Oliver, T. A. Castillo

Journal of the Arkansas Academy of Science

Redvine Brunnichia ovata (Walt.) Shinners is a perennial weed that reproduces from seed, rootstock, and rhizomes. Redvine infested areas that were exposed to different tillage practices, slicing techniques, and herbicide treatments were selected to excavate in order to observe rhizome and root morphology. When comparing tillage systems, deep tillage appeared to delay rhizome development following cultivation, but a characteristic branching occurred over time. Shallow cultivation (2.5 to 7.5m) concentrated rhizomes immediately below the depth of tillage; whereas, no-till areas concentrated rhizomes near the soil surface. Slicing the underground parts of redvine will not kill rhizomes if they are still attached …

Fire Effects On Three Trophic Levels In A Central Arkansas Grassland, Laura Skelton, Amy Polk, Brenna C. Fitzgerald, Matthew D. Moran

Journal of the Arkansas Academy of Science

We studied the effect of a late growing-season fire on the plant and foliar arthropod communities in a naturally occurring grassland. In central Arkansas, these grasslands are common on south-facing slopes where shallow soils and hot/dry weather conditions during the summer cannot support the growth of a forest community. Patches of grassland were burned in the autumn (4 November, late growing season), often the time of natural fires in Arkansas, and compared to unburned areas. Fire increased the biomass of forbs and decreased the biomass of grasses, although overall biomass was not different between treatments. Among the foliar arthropods, herbivores …

Botrytis In Wine Grapes In Western Australia, Diana Fisher, Colin Gordon, Peter Wood

Bulletins 4000 -

Botrytis, causal agent Botrytis cinerea, is a fungal disease of grapevines that is commonly referred to as Botrytis bunch rot or grey mould. Botrytis is most prevalent where warm, wet conditions are frequent, but symptoms can occur in cool, wet weather and high humidity. All grape varieties are susceptible. Varieties most at risk are those with berries that are thin-skinned and/or have tight bunches.

Some white wine grape varieties infected with Botrytis may decay, in certain conditions to produce noble rot . Wine produced from these infected bunches produce unique aromatic characters with high residual sugar and are …

Investigating The Relationship Between Cryptococcus Fagisuga And Fagus Grandifolia In Great Smoky Mountains National Park, Ashley B. Morris, Randall L. Small, Mitchell B. Cruzan

Biology Faculty Publications and Presentations

Focuses on a study which investigated the relationship between Cryptococcus fagisuga and Fagus grandifolia in Great Smoky Mountains National Park. Potential for genetic resistance; Methods; Results and discussion.

Kura Clover And Birdsfoot Trefoil Response To Soil Ph, L. R. Dehaan, M. P. Russelle, C. C. Sheaffer, N. J. Ehlke

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

Use of the rhizomatous perennial forage legume kura clover (Trifolium ambiguum M. Bieb.) has been limited by slow establishment. Mature kura clover responds to liming on some acid soils, but the soil pH required for vigorous growth of young plants is unknown. A factorial greenhouse experiment was conducted with two kura clover cultivars (Rhizo and Endura) and one cultivar of birdsfoot trefoil (Lotus corniculatus L., Norcen) planted in three soil types (Sartell loamy fine sand, Hubbard loamy sand, and Sanborg clay loam) amended with Ca(OH)₂ to obtain six soil pH levels. The experiment was performed twice, once …

Mutual Interference Of Pheromone Traps Within Trap Lines On Captures Of Boll Weevils (Coleoptera: Curculionidae), Thomas W. Sappington

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

Traps baited with the synthetic aggregation pheromone of the boll weevil (Anthonomus grandis Boheman) are often used to monitor population fluctuations, distribution, and behavior. However, many factors generate variability in daily captures, making interpretation of trapping data difficult. Previous studies have shown that wind speed in the microenvironment around a trap can greatly affect numbers captured on a given day. It is possible that variation in air movement may also generate variation in trap captures through its effects on the pheromone plume. The current study was conducted to determine whether five traps placed in a line at two commonly …

A Personal Account Of Creating The Sterile Insect Technique To Eradicate The Screwworm From Curacao, Florida And The Southeastern United States, Alfred H. Baumhover

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

The history is recounted of developing the sterile insect technique to eradicate the screwworm, Cochliomyia hominivorax (Coquerel), from the Caribbean island of Curacao, Florida and the southeastern U.S. Observations of screwworm biology and challenges faced in conducting these eradication projects are described by the author who worked on all aspects of the research and field operations. Eradication was first demonstrated on Curacao, essentially a 170 mi² outdoor laboratory. The population dynamics of the wild screwworm was determined and overflooding ratios and dispersal patterns essential for population suppression were defined. Eradication was achieved with minimal resources by attacking the pest …

Threat Of Foreign Arthropod-Borne Pathogens To Livestock In The United States, Ralph A. Bram, John E. George, Robert E. Reichard, Walter J. Tabachnick

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

There are many exotic animal pathogens throughout the world that, if introduced into the United States, could have a significant detrimental impact on the health of livestock, agricultural economy, the environment, and public health. Many of these pathogens are arthropod-borne and potential vectors are readily available in the United States. A number of these arthropod-borne pathogens are discussed here as examples that illustrate the potential risk and the consequences of inadvertent introductions. Several International agencies have a role in global surveillance and in controlling animal diseases should they begin to expand their range. The risk to the United States is …

Soil- And Plant-Water Dynamics In A C3/C4 Grassland Exposed To A Subambient To Superambient Co2 Gradient, H. Wayne Polley, Hyrum B. Johnson, Justin D. Derner

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

Plants may be more sensitive to carbon dioxide (CO₂) enrichment at subambient concentrations than at superambient concentrations, but field tests are lacking. We measured soil-water content and determined xylem pressure potentials and δ¹³C values of leaves of abundant species in a C3/C4 grassland exposed during 1997-1999 to a continuous gradient in atmospheric CO₂ spanning superambient concentrations (200-560 µmol mol^-1).

National And Regional Assessments Of Crop Yield Trends And Relative Production Efficiency : Theme 5.1. Land Use Change, Productivity And Diversification, David Stephens

Agriculture reports

National and regional assessment in Australia of relative production (yield) efficiency for wheat and other cereals providing estimates of biological production potential based on seasonal climatic conditions, compared with actual production values for selected historical dates between 1982 and 2000.

Genomewide Identification Of Proteins Secreted By The Hrp Type Iii Protein Secretion System Of Pseudomonas Syringae Pv. Tomato Dc3000, Tanja Petnicki-Ocwieja, David J. Schneider, Vincent C. Tam, Scott T. Chancey, Libo Shan, Yashitola Jamir, Lisa M. Schechter, Misty Janes, C. Robin Buell, Xiaoyan Tang, Alan Collmer, James R. Alfano

Department of Plant Pathology: Faculty Publications

The ability of Pseudomonas syringae pv. tomato DC3000 to be pathogenic on plants depends on the Hrp (hypersensitive response and pathogenicity) type III protein secretion system and the effector proteins it translocates into plant cells. Through iterative application of experimental and computational techniques, the DC3000 effector inventory has been substantially enlarged. Five homologs of known avirulence (Avr) proteins and five effector candidates, encoded by genes with putative Hrp promoters and signatures of horizontal acquisition, were demonstrated to be secreted in culture and/or translocated into Arabidopsis in a Hrp-dependent manner. These 10 Hrp-dependent outer proteins (Hops) were designated HopPtoC (Avr- PpiC2 …