Agronomy and Crop Sciences Commons^™

Effects Of Planting Date And Maturity Group On Reproductive Growth And Disease Incidence Of Soybeans In Southeast Missouri, Jeremy Austin Angotti

Student Theses and Dissertations

The objectives of this study were to determine the effects of planting date of MG III, IV, and V cultivars on yield and severity of three important diseases. Plots were inspected for frogeye leaf spot, Cercospora blight, and pod and stem blight. Myclobutanil and azoxystrobin were applied at R3 and R5 stages for fungicides treatment. In 2005 and 2006, disease infestation and cultivar means showed significant effect. Fungicide application showed control in all cultivars for 2005 and 2006. Yield in 2006 was significantly greater for May than April and June planting dates; yields were similar for April and June planting …

Resistance Screening And Control Options For Glyphosate-Resistant Palmer Amaranth (Amaranthus Palmeri) In Cotton (Gossypium Hirsutum), Ryan Christopher Doherty

Graduate Theses and Dissertations

In the mid-2000's, glyphosate-resistant Palmer amaranth biotypes began to emerge in many southern states. In 2006, glyphosate-resistant Palmer amaranth was identified in a field in Mississippi County, Arkansas. A greenhouse experiment was conducted in 2008 to screen Palmer amaranth accessions, collected in this survey, for glyphosate resistance. Inflorescence were collected from a total of 276 plants from fields were glyphosate failure occurred, representing 74 accessions in 14 counties, including Clay, Craighead, Crittenden, Greene, Jackson, Jefferson, Lawrence, Lee, Mississippi, Phillips, Poinsett, Randolph, St. Francis, and White Counties. Eight of the 74 accessions did not produce viable seed. In the greenhouse, 32 …

Arkansas Soybean Performance Tests 2012, R. D. Bond, D. G. Dombek, J. A. Still, R. M. Pryor

Arkansas Agricultural Experiment Station Research Series

Soybean variety and strain performance tests are conducted each year in Arkansas by the University of Arkansas System Division of Agriculture Arkansas Crop Variety Improvement Program. The tests provide information to companies developing varieties and/or marketing seed within the state, and aid the Arkansas Cooperative Extension Service in formulating variety recommendations for soybean producers.

Environmental Triggers Of Winter Annual Weed Emergence And Management To Reduce Soybean Cyst Nematode Reproduction On Winter Annual Weed Hosts, Rodrigo Werle

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Winter annual weeds are becoming more common in many row crop fields in the midwestern USA. The impact of winter annual weeds in cropping systems is often overlooked because these weeds complete their lifecycle near the time of crop sowing. However, delayed soil warming, competition for nutrients during initial establishment of the main crop, difficult planting operations, and yield loss are some of the problems caused by dense mats of winter annual weeds. Moreover, some of these weeds have been reported as alternative hosts for pests such as the soybean cyst nematode (Heterodera glycines, SCN), considered the most …

A Review Of Cover Crops For Eastern Nebraska, Tyler Williams

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

The focus of this project is two fold, first to provide a short literature review of cover crops (CC) and then discuss the results from a field experiment that was designed to evaluate the nitrogen contribution from cover crop mixes to the subsequent corn crop. The literature review will focus on the aspects of CC that are related to the field of study. Cover crops, as defined by the United States Department of Agriculture (USDA) are crops that are agronomically sound and grown for the purpose of erosion control or other objectives related to conservation or soil improvement. Cover crops …

Nitrous Oxide Emissions From Smooth Bromegrass Pasture Under Nitrogen Fertilizer And Ruminant Urine Application In Eastern Nebraska, Laura K. Snell

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Nitrous oxide (N₂O) is a greenhouse gas primarily produced in soils by denitrifying and nitrifying organisms. Agricultural soils account for 70% of emissions in the United States, but little data is available for contributions from managed pasture ecosystems. This study focused on the production of N₂O in smooth bromegrass (Bromus inermis Leyss.) pastures established on silt loam soils in eastern Nebraska. Thirty smooth bromegrass plots (1.5m x 1.5m) were treated with five different fertilizer treatments (0, 45, 90, 135, and 180 kg N/ha) and two urine treatments (urine and no urine). Herbage sampling was taken …

Ecology And Invasive Properties Of Musk Thistle (Carduus Nutans) In The Central Prairies Of Nebraska, Chengchou Han

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Musk thistle (Carduus nutans) is an herbaceous monocarpic herb introduced to the U. S. from Eurasia. The invasion of musk thistle can reduce forage area, soil stability, and reduce recreation and open areas for humans and wildlife.

Resistance of warm season and cool season perennial grass communities to musk thistle invasion is important for land managers to consider, especially where disturbance has made an area particularly susceptible. Our results show that disturbances, such as overgrazing can open up niches in canopies of warm season grass communities and facilitate invasion but not in cool season grass communities. The mechanism …

Meta-Analysis Of Wheat Qtl Regions Associated With Heat And Drought Stress, Marlovi Andrea Acuna Galindo

Graduate Theses and Dissertations

Heat and drought are the two most important environmental constraints to wheat production globally, are often present simultaneously and will become more severe with global climate change. This presents a unique challenge to wheat scientists who must work to develop wheat cultivars that are productive and adapted to future environmental conditions. A number of recent studies have reported quantitative trait loci (QTL) associated with heat and drought tolerance, as well as QTL for stress adaptive traits such as the availability of stem carbohydrates or crop canopy temperature. The objective of this study was to perform a meta-analysis of these QTL …

Long-Term Effects Of Rice Rotation, Tillage, And Fertility On Near-Surface Soil Carbon And Nitrogen Cycling, Jill Marie Motschenbacher

Graduate Theses and Dissertations

Rice (Oryza sativa L.)-based cropping systems are different from other row crops due to the flood-irrigation scheme used from about one month after planting to a few weeks prior to harvest. The frequent cycling between anaerobic (i.e., flooding during the growing season) and aerobic (i.e., generally, the remainder of the year) conditions can influence the rate of soil organic matter (SOM) decomposition, which can greatly influence carbon (C) and nitrogen (N) storage and sequestration in the soil over time. Therefore, a study was conducted on a silt-loam soil (fine, smectitic, thermic, Typic Albaqualf) at the Rice Research and Extension Center …

Alternative Herbicide Control Options For Glyphosate-Resistant Palmer Amaranth (Amaranthus Palmeri), George Macmillan Botha

Graduate Theses and Dissertations

The occurrence of glyphosate-resistant (GR) Palmer amaranth has prompted a shift in weed management strategies worldwide. Studies were conducted with the aim to (1) establish and compare the degree of tolerance of GR Palmer amaranth populations; (2) assess the efficacy of glufosinate, tembotrione, 2,4-D or dicamba, applied alone or tank-mixed, on Palmer amaranth with higher tolerance to glufosinate in the greenhouse and corn field, and (3) establish the mechanism involved in the tolerance of Palmer amaranth to glufosinate. Tembotrione, 2,4-D, dicamba, and glufosinate applied at 1x controlled 80 to 100%, 98 to 100%, 84 to 100%, and 94 to 100% …

Breeding For Modified Seed Composition In Soybean: Selection Of Genotypes, Yield Stability, And Environmental Effects, Luciano Miguel Jaureguy

Graduate Theses and Dissertations

The development of cultivars with modified seed composition represents an excellent alternative to cope with the world's need for more nutritious food. Understanding the genetic and environmental factors controlling crop seed quality traits is of crucial importance for such an endeavor. The objectives of this study were: a) to evaluate the efficiency of phenotype and marker-assisted selection for low stachyose and low phytate soybean breeding lines, and their yield stability, b) to study the effect of management practices planting date and delayed harvest on soybean seed composition, and c) to study the potential association between soil properties and leaf chemical …

Evaluation Of The Recombination Efficiencies Of Flp Proteins, Linh Duy Nguyen

Graduate Theses and Dissertations

Site-specific recombination systems are powerful tools for genetic modification. They have been used to integrate a transgene into a pre-defined locus and to remove marker genes from a transgene locus. Two of the most widely used site-specific recombination systems in plants are the Cre/lox system from the bacteriophage P1 and the FLP/FRT system from the yeast Saccharomyces cerevisiae. The Cre/lox system is well-characterized and is the first choice in application of site-specific recombination system. However, some applications such as marker-free site-specific gene integration require the use of two recombination systems. In addition, the availability of alternative recombination systems can offer …

False Smut Of Rice: Histological Analysis Of Infection, Liem Thi Thanh Nguyen

Graduate Theses and Dissertations

False smut of rice, caused by Ustilaginoidea virens (Cooke) Takahashi (Teleomorph: Villosiclava virens), has become a common disease in most major rice growing regions throughout the world. Considerable confusion exists regarding the infection process and the disease cycle. Therefore, a clearer understanding of pathogenesis caused by Ustilaginoidea virens is critical for future efforts to develop genetic and chemical tools to manage false smut in Arkansas and other regions of the world. The overall goal of this research was to clarify the infection process underlying false smut, with emphasis on comparing and contrasting the histological basis of root and foliar infections. …

Documentation And Control Of Acetolactate Synthase-Resistant Barnyardgrass (Echinochloa Crus-Galli) In Arkansas Rice, Michael Joshua Wilson

Graduate Theses and Dissertations

Barnyardgrass, the most problematic grass weed of Arkansas rice, was found resistant to propanil in 1990, and since then, it has evolved resistance to quinclorac and clomazone. Barnyardgrass is now believed to have evolved resistance to acetolactate synthase (ALS)-inhibiting herbicides. The goal of this research was to confirm and determine the level of resistance of the putative resistant biotype to the ALS-inhibiting herbicides imazethapyr, bispyribac, and penoxsulam and to develop herbicide programs for controlling ALS-, propanil-, quinclorac-, and clomazone-resistant barnyardgrass. The lethal dose needed to kill 50% of the putative ALS-resistant plants was higher than that of the susceptible biotype …

Intsormil- Centa’S New Bmr Sorghum Varieties Create A Surge In Dairy Production, René Clará Valencia

INTSORMIL Scientific Publications

Scientists from the INTSORMIL-CENTA project based at the National Center for Agricultural Technology and Forestry (CENTA) of El Salvador have worked for five years to develop varieties of sorghum for grain and forage that are highly nutritious to cattle. Using the gene bmr-12, received from Dr. Gebisa Ejeta of Purdue University, they combined commercial varieties CENTA S-2, S-3 CENTA, CENTA RCV and VG 146 and were able to form new varieties containing this same gene. The first generation created 76 new varieties.

Plant Responses To Heterogeneous Salinity: Growth Of The Halophyte Atriplex Nummularia Is Determined By The Root-Weighted Mean Salinity Of The Root Zone, Nadia Bazihizina, E G. Barrett-Lennard, Timothy Colmer

Grain and Other Field Crops Research Articles

Soil salinity is generally spatially heterogeneous, but our understanding of halophyte physiology under such conditions is limited. The growth and physiology of the dicotyledonous halophyte Atriplex nummularia was evaluated in split-root experiments to test whether growth is determined by: (i) the lowest; (ii) the highest; or (iii) the mean salinity of the root zone. In two experiments, plants were grown with uniform salinities or horizontally heterogeneous salinities (10–450mM NaCl in the low-salt side and 670mM in the high-salt side, or 10mM NaCl in the low-salt side and 500–1500mM in the high-salt side). The combined data showed that growth and gas …

Variedad De Sorgo Para Grano De Ciclo Precoz Centa Liberal, Intsormil-Centa

INTSORMIL Scientific Publications

El sorgo es una alternativa para las familias agricultoras dedicadas a la producción de grano debido a la capacidad que tiene de tolerar sequías prolongadas.

Sus características lo vuelven una alternativa, incluso para sustituir al maíz, aún con las limitantes hídricas que se han incrementado en los últimos años debido a los efectos del cambio climático.

Es un cultivo rústico capaz de producir en condiciones adversas de suelo (excepto suelos mal drenados), clima y de poco manejo agronómico; se adapta desde los 10 hasta los 1000 m.s.n.m.

La variedad CENTA Liberal que hoy se pone a disposición de los productores …

Centa S-3 Bmr Y Centa S-4 Bmr: Variedades De Sorgo Forrajero Para Ensilaje, Intsormil-Centa

INTSORMIL Scientific Publications

Siendo la nutrición animal un factor importante para el éxito de la ganadería de leche y carne en El Salvador, el Centro Nacional de Tecnología Agropecuaria y Forestal “Enrique Álvarez Córdova” (CENTA), en colaboración con el Instituto de Sorgo, Mijo y Otros Granos (INTSORMIL), ha desarrollado dos nuevas variedades de sorgo para ensilaje con alta digestibilidad, capaces de incrementar la producción de leche y carne en el ganado bovino con el objetivo de fortalecer la seguridad alimentaria en el país.

La utilización del sorgo en forma de ensilaje se ha incrementado en nuestro país a partir de los años 80, …

Economic Contribution Of The Agricultural Sector To The Arkansas Economy In 2010, Katherine Mcgraw, Jennie Popp, Wayne Miller

AAES Research Reports and Research Bulletins

This report is the seventh in a series of reports examining agriculture’s economic contribution on the Arkansas economy. Utilizing data from the United States Bureau of Economic Analysis (BEA), USDA Economic Research Service (ERS), USDA National Agricultural Statistics Service (NASS), and Minnesota IMPLAN Group, Inc. (MIG), the economic contribution of agriculture on the Arkansas economy was estimated for the most recent year available, 2010. Gross Domestic Product (GDP) by State information for Arkansas in 2010 was compared with those of other states in the Southeast U.S. to give a measure of the relative importance of agriculture in Arkansas.2 The total …

Survey Of Endosymbionts In The Diaphorina Citri Metagenome And Assembly Of A Wolbachia Wdi Draft Genome, Surya Saha, Wayne B. Hunter, Justin Reese, J. Kent Morgan, Mizuri Marutani-Hert, Hong Huang, Magdalen Lindeberg

School of Information Faculty Publications

Diaphorina citri (Hemiptera: Psyllidae), the Asian citrus psyllid, is the insect vector of Ca. Liberibacter asiaticus, the causal agent of citrus greening disease. Sequencing of the D. citrimetagenome has been initiated to gain better understanding of the biology of this organism and the potential roles of its bacterial endosymbionts. To corroborate candidate endosymbionts previously identified by rDNA amplification, raw reads from the D. citri metagenome sequence were mapped to reference genome sequences. Results of the read mapping provided the most support for Wolbachia and an enteric bacterium most similar to Salmonella. Wolbachia-derived reads were extracted using …

Summaries Of Arkansas Cotton Research 2011, Derrick M. Oosterhuis

Arkansas Agricultural Experiment Station Research Series

No abstract provided.

Marketing Contracts, Overconfidence, And Timing In The Canadian Wheat Market, Fabio L. Mattos, Stefanie A. Fryza

Department of Agronomy and Horticulture: Faculty Publications

This paper investigates factors that impact marketing performance in the Canadian wheat market. Using data provided by the Canadian Wheat Board (CWB) for six crop years, results indicate that producers were not able to profitably use all marketing contracts offered by the CWB, earlier pricing tended to generate better performance, there was a negative relationship between activeness and performance (suggesting overconfidence in marketing skills), and performance was generally worse in volatile crop years. Further analysis reveals some of these findings differ when outperforming and underperforming producers are investigated separately, particularly with respect to activeness and volatility.

Arkansas Corn And Grain Sorghum Performance Tests 2012, R. D. Bond, D. G. Dombek, J. A. Still, R. M. Pryor

Arkansas Agricultural Experiment Station Research Series

Corn and grain sorghum performance tests are conducted each year in Arkansas by the University of Arkansas System Division of Agriculture. The tests provide information to companies marketing seed within the state and aid the Arkansas Cooperative Extension Service in formulating recommendations for producers.

Amelioration Of Root Disease Of Subterranean Clover (Trifolium Subterraneum) By Mineral Nutrients, Tim Scanlon, Tiernan A. O’Rourke, Megan H. Ryan, Martin J. Barbetti, Krishnapillai Sivasithamparam

Journal articles

Subterranean clover (Trifolium subterraneum) is a key pasture legume across southern Australia and elsewhere. Decline in subterranean clover pastures was first recognised in Australia during the 1960s and manifests as an increase in weeds and a decrease in desirable legume species. While both root disease and poor nutrition contribute to subterranean clover pasture decline, the relationships between root disease and nutrition have not been determined. The objective of this study was to define these relationships. Field experiments were undertaken to determine the nutritional and pathogen status of soils and subterranean clover from three Western Australian field sites. Subsequently, …

Innovative Approach To Active Learning, John G. Graveel, George E. Van Scoyoc

IMPACT Presentations

Presentation on a course redesign and project plan given at the American Society of Agronomy Annual Meeting, Cincinnati, OH.

Asareca-Intsormil: Regional Sorghum Research And Development Workshop, September 2–6, 2012, Executive Hotel, Adama, Ethiopia, Kimberly Christiansen

INTSORMIL Scientific Publications

Priorities in Sorghum Research and Development Cross-Cutting Elements

All priorities should be cognizant and address:

Gender responsiveness

User friendliness in sharing knowledge and information

Sustainable growth

Capacity building

Collaboration with public and private partners especially NARS, and regional and international organizations

Production

Integrated soil and water management in response to climate change

Integrated pest management

Cropping systems

Mechanization to alleviate drudgery

Breeding/Genetics

Breeding high yielding sorghum cultivars with enhanced ecological adaptation (drought tolerance and Striga resistance and diseases and pests) and superior grain quality

Development, release and distribution of enhanced sorghum germplasm materials with desired end-use quality attributes (malt, biofuel, …

2013 Barley Variety Sowing Guide For Western Australia, Blakely Paynter, Andrea Hills, Harmohinder Dhammu, Sanjiv Gupta

Bulletins 4000 -

This publication presents general information on market demand by industry sector, variety and Port Zone for each of the malting barley varieties that will potentially be segregated in Western Australia at the 2013/14 harvest (Tables 1, 2 and 3).

This information is presented on behalf of the Grain Industry of Western Australia (GIWA) Barley Council. It represents the expected demand from domestic and international customers of Western Australian barley. Before planting any variety with a malting or food classification growers are advised to talk to their preferred grain acquirer to determine their demand for each malt and food variety, potential …

Studies Of Drought Tolerance Of Hard Red Winter Wheat (Triticum Aestivum L.) Cultivars In Nebraska, Sumardi Bin Abdul Hamid

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

In Nebraska, about 75% of the wheat production is in the western half of the state, and about 92% of the winter wheat acreage is in dryland production, where productivity is limited by low and/or uncertain rainfall. We have investigated the effects of water stress on few established winter wheat (Triticum aestivumL.) cultivars, which are known for their superior adaptation to either rainfed or irrigated wheat production systems in western Nebraska. We also began a study to investigate the variation in the root system architecture to confer drought tolerance in winter wheat. The objectives of this study were …

Arkansas Wheat Cultivar Performance Tests 2011-2012, R. E. Mason, R. G. Miller, J. P. Kelley, E. A. Milus

Arkansas Agricultural Experiment Station Research Series

Wheat cultivar performance tests are conducted each year in Arkansas by the Arkansas Agricultural Experiment Station, Department of Crop, Soil and Environmental Sciences. The tests provide information to companies developing cultivars and/or marketing seed within the state and aid the Arkansas Cooperative Extension Service in formulating cultivar recommendations for small-grain producers.

Effects Of Meloidogyne Incognita, Soil Physical Parameters, And Thielaviopsis Basicola On Cotton Root Architecture And Plant Growth, Jianbing Ma

Graduate Theses and Dissertations

The root-knot nematode, Meloidogyne incognita, and the seedling pathogen, Thielaviopsis basicola, commonly co-exist in Arkansas cotton fields and may interact resulting in increased losses. The primary objective of this research was to evaluate the effects of soil physical parameters on these soilborne pathogens and cotton growth in controlled environmental, field, and microplot studies. Controlled environmental experiments used two soil bulk densities and four pathogen treatments: non-infested soil, soil infested with M. incognita or T. basicola and soil infested with both pathogens. The results indicated bulk density generally did not affect seedling growth or disease since soils had low penetration resistance …