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Wheat (Triticum Aestivum) Nam Proteins Regulate The Translocation Of Iron, Zinc, And Nitrogen Compounds From Vegetative Tissues To Grain, Brian M. Waters, Cristobal Uauy, Jorge Dubcovsky, Michael A. Grusak

Department of Agronomy and Horticulture: Faculty Publications

The NAM-B1 gene is a NAC transcription factor that affects grain nutrient concentrations in wheat (Triticum aestivum). An RNAi line with reduced expression of NAM genes has lower grain protein, iron (Fe), and zinc (Zn) concentrations. To determine whether decreased remobilization, lower plant uptake, or decreased partitioning to grain are responsible for this phenotype, mineral dynamics were quantified in wheat tissues throughout grain development. Control and RNAi wheat were grown in potting mix and hydroponics. Mineral (Ca, Cu, Fe, K, Mg, Mn, P, S, and Zn) and nitrogen (N) contents of organs were determined at regular intervals to …

Effects Of Nitrogen Supply On The Root Morphology Of Corn And Velvetleaf, Kimberly D. Bonifas, John L. Lindquist

Department of Agronomy and Horticulture: Faculty Publications

Root morphology will affect interplant competition for soil nutrients. Research was conducted to assess fine root fraction, mean root radius, specific root length, root length density, and nitrogen (N) uptake per unit fine root biomass of corn and velvetleaf over time and in response to nitrogen supply. Pots containing either corn or velvetleaf were embedded in the ground and received one of three N treatments. Plants were destructively sampled on 10 dates during each of two years and root subsamples analyzed using root scanning software. While corn root morphology was more responsive to N supply than velvetleaf, velvetleaf N uptake …

Switchgrass For Forage And Bioenergy: Ii. Effects Of P And K Fertilization, John A. Guretzky, Maru Kering, Jon Biermacher, Billy Cook

Department of Agronomy and Horticulture: Faculty Publications

Switchgrass (Panicum virgatum L.) has been targeted for cellulosic ethanol production. Our objective was to evaluate effects of P and K fertilization on switchgrass biomass yields. Experiments were established in switchgrass (cv. Alamo) fields planted at three Oklahoma locations in 2007. Interactions of N and P fertilizer rates were evaluated on two sites that had low soil test P (6 to 9 kg/ha). Interactions of N and K fertilizer rates and harvest system were evaluated on a site that had low soil test K (134 kg/ha). In the N and P rate experiments, biomass yields during establishment …

Grazing Lands And Soil Carbon Storage, John A. Guretzky

Department of Agronomy and Horticulture: Faculty Publications

On March 31, 2009, a draft discussion of the American Clean Energy and Security Act of 2009 was released to the public. The bill contains four sections addressing:

1. clean energy;
2. energy efficiency;
3. reducing global warming pollution; and
4. transitioning to a clean energy economy.

Section 3 contains a description of the proposed cap-and-trade program designed to reduce industrial emissions of greenhouse gases (GHG) including carbon dioxide (CO₂), methane (CH4), nitrous oxide (N₂O), hydro-fluorocarbons (HFCs), perfluorocarbons (PFCs), sulfur hexafluoride (SF6) and nitrogen trifluoride (NF3). Agricultural sources, although largely diffuse and not regulated directly by the bill, account for …

Switchgrass For Forage And Bioenergy: I. Effects Of Nitrogen Rate And Harvest System, Maru Kering, J. T. Biermacher, Billy Cook, John A. Guretzky

Department of Agronomy and Horticulture: Faculty Publications

Switchgrass (Panicum virgatum L.) has been targeted for cellulosic ethanol production. Our objective was to evaluate effects of location, harvest system, and N fertilizer rates on switchgrass biomass yield and N, P, and K removal. Randomized complete block experiments with four replications were established on one-year old stands of ‘Alamo’ switchgrass at two Oklahoma locations in 2008. Harvest system and N rate interactions affected total annual yield. Biomass yields ranged from 9020 to 10530 kg/ha across harvest systems when no N was applied. With application of 179 kg N/ha, biomass yields averaged 10715, 13912, and 16516 kg/ha when harvested at …

Alternative Methods For Wetland Restoration In The Rainwater Basin, Nebraska, Usa, Nancy Nicolai, James L. Stubbendieck

Department of Agronomy and Horticulture: Faculty Publications

South-central Nebraska is recognized as a focal point of the mid-continent migratory waterfowl flyway. Substantial wetland alterations led to a critical need for restoration. Managers have restored wetlands by scraping with heavy earthmoving equipment to remove excess organic material and near-monocultures of reed canarygrass (Phalaris arundinacea L.) but managers report high costs and topsoil perturbation. Moderate livestock grazing was tested to compare results with those achieved with mechanical techniques. Advantages of grazing could include low costs and less soil perturbation. During the 2006 and 2007 growing seasons, we compared cover of bare ground and open water and plant species …

Agroecology As A Science, A Movement And A Practice. A Review, A. Wezel, S. Bellon, T. Doré, Charles A. Francis, D. Vallod, C. David

Department of Agronomy and Horticulture: Faculty Publications

Agroecology involves various approaches to solve actual challenges of agricultural production. Though agroecology initially dealt primarily with crop production and protection aspects, in recent decades new dimensions such as environmental, social, economic, ethical and development issues are becoming relevant. Today, the term ‘agroecology’ means either a scientific discipline, agricultural practice, or political or social movement. Here we study the different meanings of agroecology. For that we analyse the historical development of agroecology. We present examples from USA, Brazil, Germany, and France. We study and discuss the evolution of different meanings agroecology. The use of the term agroecology can be traced …

Nutrient And Chemical Properties Of Aging Golf Course Putting Greens As Impacted By Soil Depth And Mat Development, Ty A. Mcclellan, Roch E. Gaussoin, Bob Shearman, Charles S. Wortmann, Martha Mamo, Garald L. Horse, David B. Marx

Department of Agronomy and Horticulture: Faculty Publications

Nutrient and chemical changes in turfgrass sand-based root zones are not well understood. This study was conducted to characterize nutrient and chemical properties in putting greens influenced by root zone mixture and establishment treatment, putting green age, and soil depth. Putting greens were constructed and established with Agrostis stolonifera L. in sequential years from 1997 to 2000. Treatments included root zone mixtures of 80:20 (v:v) sand and sphagnum peat and 80:15:5 (v:v:v) sand, sphagnum peat, and soil, and accelerated versus controlled establishment. In the establishment year, the accelerated treatment received 2.6-, 3.0-, and 2.6-fold more nitrogen, phosphorus, and potassium, respectively, …

Forage Yields From 2008-2009 Ryegrass, Jagadeesh Mosali, John A. Guretzky, M. Saha, S. Norton

Department of Agronomy and Horticulture: Faculty Publications

Introduction

Livestock and forage production are the largest contributors to agricultural income in the primary service region of the Noble Foundation. The ryegrass (Lolium multiflorum L) variety testing program is designed to provide up-to-date performance information to cooperators and producers in Oklahoma and Texas about ryegrass varieties that are commercially and commonly available. In addition, the program provides a tool to evaluate and compare experimental breeding lines emerging from the Noble Foundation breeding program as well as other public and private breeding programs. The program is intended to furnish producers with supplemental information, aid decision-making and idea formation. The information …

Forage Yields From 2008-2009 Small Grains, Jagadeesh Mosali, John A. Guretzky, M. Saha, J. Baker, S. Norton

Department of Agronomy and Horticulture: Faculty Publications

Introduction

Livestock and forage production are the largest contributors to agricultural income in the primary service region of the Noble Foundation. The small grains variety testing program which includes oats, rye, triticale and wheat is designed to provide up-to-date performance information to producers in Oklahoma and Texas about varieties that are commercially and commonly available. In addition, the program provides a tool to evaluate and compare experimental breeding lines emerging from the Noble Foundation breeding program as well as other public and private breeding programs. The program is intended to furnish producers with supplemental information and to aid decision-making and …

Research Emphasis – Forage And Bioenergy Crop Management, John A. Guretzky

Department of Agronomy and Horticulture: Faculty Publications

Guretzky specializes in research on forage and bioenergy crop management that will assist agricultural producers and landowners in meeting their goals. The first area of research involves Drs. Jon Biermacher and Billy Cook for the evaluation of management practices of switchgrass in forage and bioenergy systems. Objectives include: 1.) assessing potential on-farm biomass yields and production economics of switchgrass; 2.) documenting effects of location, harvest system and nitrogen fertilizer rates on biomass yields, forage quality, stand persistence and nutrient removal rates; 3.) evaluating establishment and biomass production responses to phosphorus and potassium fertilization; 4.) determining how stocker cattle gains on …

Blue Fescue Overseeding Improves Performance Of Fairway Height Buffalograsses, Bekele G. Abeyo, Robert C. Shearman, Roch E. Gaussoin, Leonard A. Wit, Desalegn D. Serba, Ugur Bilgili

Department of Agronomy and Horticulture: Faculty Publications

Buffalograss [Buchloe dactyloides (Nutt.) Engelm.] use as a fairway turfgrass is limited in northern portions of its adaptation zone by its extended winter dormancy and tan coloration in early spring and late fall. Cool-season grasses mixed with buffalograss could enhance turfgrass appearance and performance in fall and early spring. Research was conducted near Mead, NE, with eight buffalograss genotypes maintained under fairway conditions to determine the effect of blue fescue (Festuca ovina L. var. glauca Lam.) overseeding rate on turfgrass performance. Interactions were nonsignificant in most cases so main effects are emphasized. Differences were observed between seeding rates and …

Detection And Validation Of Single Feature Polymorphisms Using Rna Expression Data From A Rice Genome Array, Sung-Hyun Kim, Prasanna R. Bhat, Xinping Cui, Harkamal Walia, Jin Xu, Steve Wanamaker, Abdelbagi M. Ismail, Clyde Wilson, Timothy J. Close

Department of Agronomy and Horticulture: Faculty Publications

Background: A large number of genetic variations have been identified in rice. Such variations must in many cases control phenotypic differences in abiotic stress tolerance and other traits. A single feature polymorphism (SFP) is an oligonucleotide array-based polymorphism which can be used for identification of SNPs or insertion/deletions (INDELs) for high throughput genotyping and high density mapping. Here we applied SFP markers to a lingering question about the source of salt tolerance in a particular rice recombinant inbred line (RIL) derived from a salt tolerant and salt sensitive parent. Results: Expression data obtained by hybridizing RNA to an oligonucleotide array …

Antibiotic Use In Animal Production: Environmental Concerns, Teshome H. Regassa, Richard K. Koelsch, Charles S. Wortmann, Richard F. Randle, Akwasi A. Abunyewa

Department of Agronomy and Horticulture: Faculty Publications

Introduction

Antibiotic1 use in animal production has led to improved feed use efficiency and increased growth rates. In turn, these resulted in reduced food production costs and reduced excrement of manure nutrients which may cause pollution problems.

On the other hand, antibiotic use leads to antibiotic resistance and a possible reduction in effectiveness of treatment options for both animals and humans. This publication addresses these issues.

Disease-causing microorganisms2, including bacteria,are the most diverse and numerous organisms on earth. Diverse in their habitat, environmental adaptation, and mechanisms of reproduction, they have short generations with high multiplication rates. Such characteristics help develop …

Gibberellic Acid Promotes Seed Germination In Penstemon Digitalis Cv. Husker Red, Anderson Machado De Mello, Nereu Augusto Streck, Erin E. Blankenship, Ellen Paparozzi

Department of Agronomy and Horticulture: Faculty Publications

Penstemon seed often shows an inconsistent or a low germination percentage. Although most select cultivars are propagated by cuttings, for export to other countries, seed is preferred. Three experiments were conducted to determine if soaking seed in gibberellic acid (GA₃) would increase seed germination of Penstemon digitalis cv. Husker Red. GA₃ concentrations used were 0, 10, 50, 100, 200, and 500 mg∙L^–1 (first experiment); 0, 500, 1000, and 1500 mg∙L^–1 (second experiment); and 0, 500, and 1000 mg∙L^–1 (third experiment). The first and second experiments were conducted in a growth chamber, whereas the third …

Bulked Segregant Analysis Using The Goldengate Assay To Locate The Rpp3 Locus That Confers Resistance To Soybean Rust In Soybean, D. L. Hyten, James R. Smith, Reid D. Frederick, Mark L. Tucker, Qijian Song, P. B. Cregan

Department of Agronomy and Horticulture: Faculty Publications

Few resistance loci to soybean rust (SBR), caused by Phakopsora pachyrhizi Syd., have been genetically mapped and linked to molecular markers that can be used for marker assisted selection. New technologies are available for single nucleotide polymorphism (SNP) genotyping that can be used to rapidly map traits controlled by single loci such as resistance to SBR. Our objective was to demonstrate that the highthroughput SNP genotyping method known as the GoldenGate assay can be used to perform bulked segregant analysis (BSA) to fi nd candidate regions to facilitate effi cient mapping of a dominant resistant locus to SBR designated Rpp3 …

Non-Destructive Determination Of Maize Leaf And Canopy Chlorophyll Content, Veronica Ciganda, Anatoly A. Gitelson, James S. Schepers

Department of Agronomy and Horticulture: Faculty Publications

The objective of this study was to develop a rapid non-destructive technique to estimate total chlorophyll (Chl) content in a maize canopy using Chl content in a single leaf. The approach was (1) to calibrate and validate a reflectance-based nondestructive technique to estimate leaf Chl in maize; (2) to quantify the relative contribution of each leaf Chl to the total Chl in the canopy; and (3) to establish a relationship between leaf Chl content and total Chl in a maize canopy. The Red Edge Chlorophyll Index Cl_{red edge} = (R_NIR/R_{red edge})-1 based on …

Limits To Maize Productivity In The Western Corn-Belt: A Simulation Analysis For Fully Irrigated And Rainfed Conditions, Patricio Grassini, Haishun Yang, Kenneth G. Cassman

Department of Agronomy and Horticulture: Faculty Publications

Unlike the Central and Eastern U.S. Corn-Belt where maize is grown almost entirely under rainfed conditions, maize in the Western Corn-Belt is produced under both irrigated (3.2 million ha) and rainfed (4.1 million ha) conditions. Simulation modeling, regression, and boundary-function analysis were used to assess constraints to maize productivity in the Western Corn-Belt. Aboveground biomass, grain yield, and water balance were simulated for fully irrigated and rainfed crops, using 20-year weather records from 18 locations in combination with actual soil, planting date, plant population, and hybrid-maturity data. Mean values of meteorological variables were estimated for three growth periods (pre- and …

A Nonsense Mutation In A Cinnamyl Alcohol Dehydrogenase Gene Is Responsible For The Sorghum Brown Midrib6 Phenotype1[W][Oa], Scott E. Sattler, Aaron J. Saathoff, Eric J. Haas, Nathan A. Palmer, Deanna L. Funnell, Gautam Sarath, Jeffrey F. Pedersen

Department of Agronomy and Horticulture: Faculty Publications

Recently, bmr6 plants were shown to have limited cinnamyl alcohol dehydrogenase activity (CAD; EC 1.1.1.195), the enzyme that catalyzes the conversion of hydroxycinnamoyl aldehydes (monolignals) to monolignols. A candidate gene approach was taken to identify Bmr6. Two CAD genes (Sb02g024190 and Sb04g005950) were identified in the sorghum genome based on similarity to known CAD genes and through DNA sequencing a nonsense mutation was discovered in Sb04g005950 that results in a truncated protein lacking the NADPH-binding and C-terminal catalytic domains. Immunoblotting confirmed that the Bmr6 protein was absent in protein extracts from bmr6 plants. Phylogenetic analysis indicated that Bmr6 is …

High-Yielding Corn Response To Applied Phosphorus, Potassium, And Sulfur In Nebraska, Charles S. Wortmann, Achim R. Dobermann, Richard B. Ferguson, Gary W. Hergert, Charles A. Shapiro, D. D. Tarkalson, Daniel T. Walters

Department of Agronomy and Horticulture: Faculty Publications

Nutrient management recommendations may change as yield levels and efficiency of crop production increase. Recommendations for P, K, and S were evaluated using results from 34 irrigated corn (Zea mays L.) trials conducted in diverse situations across Nebraska. The mean yield was 14.7 Mg ha^-1 with adequate fertilizer applied. Th e median harvest index values were 0.52, 0.89, 0.15, and 0.56 for biomass, P, K, and S, respectively. Median grain yields were 372, 49, and 613 kg kg^-1 of above-ground plant uptake of P, K, and S, respectively. The estimated critical Bray-1 P level for corn response …

Evaluation Of Glyphosate-Tolerant And Conventional Alfalfa Weed Control Systems During The First Year Of Establishment, Robert Wilson Jr., Paul Burgener

Department of Agronomy and Horticulture: Faculty Publications

A field trial was conducted for 3 yr (2005 through 2007) near Scottsbluff, NE, to examine weed control, crop safety, forage production, and economics of glyphosate-tolerant and conventional alfalfa establishment systems. Glyphosate applied to alfalfa at the unifoliate growth stage provided 67% weed control and was similar to imazamox applied at the two-trifoliate leaf stage. Delaying glyphosate application until alfalfa had reached the two-trifoliate growth stage improved weed control to 83%, and weed control was similar to imazamox plus 2,4-DB and imazethapyr plus 2,4-DB. Imazamox and imazethapyr caused minor crop injury, and the addition of bromoxynil or 2,4-DB to both …

Quantum Simulation Of High-Order Harmonic Spectra Of The Hydrogen Atom, A. D. Bandrauk, S. Chelkowski, Dennis J. Diestler, J. Manz, K.-J. Yuan

Department of Agronomy and Horticulture: Faculty Publications

Three alternative forms of harmonic spectra, based on the dipole moment, dipole velocity, and dipole acceleration, are compared by a numerical solution of the Schrödinger equation for a hydrogen atom interacting with a linearly polarized laser pulse, whose electric field is given by E(t)= E₀f(t)cos(ω₀t + η) with Gaussian carrier envelope f(t) = exp(−t² /δ²). The carrier frequency ω₀ is fixed to correspond to a wavelength of 800 nm. Spectra for a selection of pulses, for which the intensity I₀=cε₀E²₀, duration T∞ δ, …

Farmers And Nature Conservation: What Is Known About Attitudes, Context Factors And Actions Affecting Conservation?, Johan Ahnström, Jenny Höckert, Hanna L. Bergea, Charles A. Francis, Peter Skelton, Lars Hallgren

Department of Agronomy and Horticulture: Faculty Publications

Farmers’ attitudes towards viability of specific conservation practices or actions strongly impact their decisions on adoption and change. This review of ‘attitude’ information reveals a wide range of perceptions about what conservation means and what the impacts of adoption will mean in economic and environmental terms. Farmers operate in a tight financial situation, and in parts of the world they are highly dependent on government subsidies, and cannot afford to risk losing that support. Use of conservation practices is most effective when these are understood in the context of the individual farm, and decisions are rooted in land and resource …

Evaluation Of The Waxy Endosperm Trait In Proso Millet (Panicum Miliaceum), Robert A. Graybosch, D. D. Baltensperger

Department of Agronomy and Horticulture: Faculty Publications

The entire USDA-ARS maintained collection of 650 accessions of proso millet (Panicum miliaceum L.) was evaluated for the presence of accessions with waxy (amylose-free) endosperm starch. Six accessions, five of which derived from mainland China, were identified. Segregation ratios for waxy endosperm were evaluated in F₂ and F₃ populations derived from crosses between two waxy accessions, PI 436625 (Lung Shu 16) and PI 436626 (Lung Shu 18), and several wildtype accessions. The waxy trait was found to be under the control of duplicate recessive alleles at two loci, herein designated wx-1 and wx-2. Wild-type alleles at …

Mapping And Confirmation Of A New Allele At Rpp1 From Soybean Pi 594538a Conferring Rb Lesion–Type Resistance To Soybean Rust, Nanda Chakraborty, Joe Curley, Reid D. Frederick, D. L. Hyten, Randall L. Nelson, Glen L. Hartman, Brian W. Diers

Department of Agronomy and Horticulture: Faculty Publications

Soybean rust, caused by Phakopsora pachyrhizi (H. Sydow & Sydow), is a destructive soybean [Glycine max (L.) Merr.] disease and identification of new resistance genes is essential for effective rust management. Our research objectives were to map and confirm the location of resistance gene(s) in PI 594538A using a population of 98 F_3:4 lines from across between PI 594538A (reddish-brown [RB] lesions) and the susceptible cultivar Loda (tan [TAN] lesions). The lines were inoculated with the P. pachyrhizi isolate ZM01-1 from Zimbabwe. The RB resistance in PI 594538A mapped on linkage group G as a single dominant gene. …