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Growth And Productivity Of Irrigated Rice (Oryza Sativa L.) For A Tropical High Altitude Environment In Rwanda, Elie Rene Gasore

Graduate Theses and Dissertations

Yield components, grain yield, biomass and plant N accumulation, and N fertilizer responses of irrigated rice (Oryza sativa, L.) were evaluated for a tropical inland valley environment in the high altitudes in Rwanda. Effects were measured for nitrogen (N) fertilizer rate (0, 60, 90,120,150,180 kg N ha-1), season, growth stage and cultivar of different subspecies and plant types during 2012 dry season (DS) and 2013 wet season (WS) at Cyili Rice Research Farm (1380 m above sea level). Variations in irradiance (17.2± 0.32 MJ m-2 day-1 in DS and 9.4 ± 0.66 MJ m-2 day-1in WS) were linked to seasonal …

Managing Drought Stress In California Agricultural Systems, Gregory D. Brittain Jr.

Doctor of Plant Health Program: Dissertations and Student Research

California is currently facing a historic drought, and this has led many farmers in the state to severely cut back on irrigation. Optimal use of water for irrigation requires a comprehensive understanding of how plants respond physiologically to water stress (Chapter 1). By monitoring water requirements in crops and managing irrigation to meet those requirements, growers can significantly reduce water use (Chapter 2). This can be done through improving application efficiency of irrigation technology as well as increasing the water use efficiency of the crops themselves. Deficit irrigation practices can be used to manipulate the physiology of water use in …

Regeneration And Transformation Of Common Bean (Phaseolus Vulgaris L.), Iqbal Singh

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

Common bean is the most important grain legume for direct human consumption and serves as main source of dietary protein for millions of people in developing world. Genetic transformation methods can serve as an important tool to complement traditional plant breeding methods for common bean improvement. Low transformation frequencies and unstable genetic integration associated with biolistic methods limits its use for routine transformation of common bean. In an attempt to develop Agrobacterium tumefaciens mediated transformation protocol for common bean, potential of primary leaves as an explant was analyzed following unsuccessful results with other tissues. Primary leaf explants were prepared from …

Micronutrient Foliar Analysis And Supplementation In Nutrient Management For High Yield Maize (Zea Mays L.), Zachary P. Stewart

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

Micronutrient supplementation in maize production is of growing interest to producers and agronomists as means to further increase yield as other crop needs are increasingly met. Plant tissue and soil sampling for micronutrient concentrations have been used to determine likely responses to micronutrient supplementation. Nebraska soils are generally micronutrient sufficient and usually do not have soil or plant tissue micronutrient concentrations below critical levels, however, during precise periods where specific micronutrients are in greatest need due to physiological demands, there may be opportunity for micronutrient supplementation to increase grain yield. The compiled chapters indicate that in most scenarios in Nebraska, …

Ws-2 Introgression In A Proportion Of Arabidopsis Thaliana Col-0 Stock Seed Produces Specific Phenotypes And Highlights The Importance Of Routine Genetic Verification, Mon-Ray Shao, Vikas Shedge, Hardik Kundariya, Fredric R. Lehle, Sally Ann Mackenzie

Department of Agronomy and Horticulture: Faculty Publications

Arabidopsis thaliana is an important model organism with a robust network of resources that has been of enormous value to the plant science research community. The use of isogenic material as a reference point or control is critical for many types of experiments in plant molecular biology and genetics. Recently, we noticed that some seed from a common source of the widely used Columbia-0 (Col-0) strain gave rise to plants showing features atypical for this strain. Whole-genome DNA-sequencing and allelespecific PCR assays confirmed that the abnormal individuals contain multiple introgressions from the ecotype Wassilewskija-2 (Ws-2), as described below. This …

Winter Cover Crops Impact On The Distribution Of Soil Inorganic Nitrogen And Subsequent Crop Uptake And Yield Following Fall Applied Anhydrous Ammonium, William Travis Deppe

Theses and Dissertations

The pairing of cover crops with spring application of nitrogen has shown improved nitrogen efficiency in corn production systems. However, studies have shown that only 50% of central Illinois farmers practice spring application of nitrogen. Furthermore, the literature demonstrates that in years with above average rainfall, fall applied N management systems are more susceptible to N loading relative to spring systems. Therefore, the objective of this research was to determine the efficacy of winter cover crops to impact the distribution of soil inorganic N following fall applied anhydrous ammonium. The experimental site is located at the Illinois State University Research …

Igrow Corn: Best Management Practices, David E. Clay, Gregg G. Carlson, Sharon A. Clay, Emmanuel Byamukama

Agronomy, Horticulture, and Plant Science Books

No abstract provided.

Mapping Qtls And Association Of Differentially Expressed Gene Transcripts For Multiple Agronomic Traits Under Different Nitrogen Levels In Sorghum, Malleswari Gelli, Sharon E. Mitchell, Kan Liu, Thomas E. Clemente, Donald P. Weeks, Chi Zhang, David R. Holding, Ismail M. Dweikat

Department of Agronomy and Horticulture: Faculty Publications

Background: Sorghum is an important C₄ crop which relies on applied Nitrogen fertilizers (N) for optimal yields, of which substantial amounts are lost into the atmosphere. Understanding the genetic variation of sorghum in response to limited nitrogen supply is important for elucidating the underlying genetic mechanisms of nitrogen utilization.

Results: A bi-parental mapping population consisting of 131 recombinant inbred lines (RILs) was used to map quantitative trait loci (QTLs) influencing different agronomic traits evaluated under normal N (100 kg.ha⁻¹ fertilizer) and low N (0 kg.ha⁻¹ fertilizer) conditions. A linkage map spanning 1614 cM was developed …

Restoration Of Eroded Lands With Biochar As Soil Amendment In South Dakota, Saroop S. Sandhu

Electronic Theses and Dissertations

Biochar is produced from incomplete pyrolysis of plant biomass. Due to the unique properties of biochar such as a higher number of micropores, surface area and carbon content, and recalcitrant nature of carbon, biochar is hypothesized to improve physical and hydrological properties of soil. This study assesses the impact of biochar on soil organic carbon, physical and hydrological properties of two landscape positions under a corn (Zea mays L.)-soybean (Glycine max L.) rotation. Three types of biochar including corn stover, ponderosa pine (Pinus ponderosa Lawson and C. Lawson) wood residue, and switchgrass (Panicum virgatum L.) were applied in the field …

Contents, Discovery Editors

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

No abstract provided.

Discovery: The Student Journal Of Dale Bumpers College Of Agricultural, Food And Life Sciences - Volume 17 2016, Several Authors

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

No abstract provided.

Bumpers College Students In Action, Discovery Editors

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

No abstract provided.

Effects Of Corn (Zea Mays L.) Stover Removal And Leaching On Soil Test And Whole Plant K Levels In Corn And K Fertilization/High-Input Treatments On Soybean Using Site-Specific Management To Increase Soybean (Glycine Max) Production In South Dakota, Nick J. Schiltz

Electronic Theses and Dissertations

Potassium is important for crop production. Corn stover removal has the potential to reduce exchangeable and soluble soil potassium (K+) needed for optimal plant growth in addition to grain yield. An experiment was conducted in Aurora, SD, USA, to observe the effects of corn stover removal on water soluble and exchangeable soil test K+ (STK) levels and corn grain yields across a five-year period. Abundant K+ reserves were recorded between the initial and final sampling periods. While corn grain yields were affected by removing corn biomass, exchangeable and solution K+ levels were relatively unaffected by stover removal. Potassium fertilizer has …

Aspergillus And Aflatoxin In Groundnut (Arachis Hypogaea L.) And Groundnut Cake In Eastern Ethiopia, Abdi Mohammed, Alemayehu Chala, Mashilla Dejene, Chemeda Fininsa, David A. Hoisington, Victor S. Sobolev, R. S. Arias

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

This study was conducted to assess major Aspergillus species and aflatoxins associated with groundnut seeds and cake in Eastern Ethiopia and evaluate growers’ management practices. A total of 160 groundnut seed samples from farmers’ stores and 50 groundnut cake samples from cafe and restaurants were collected. Fungal isolation was done from groundnut seed samples. Aspergillus flavus was the dominant species followed by Aspergillus parasiticus. Aflatoxin analyses of groundnut seed samples were performed using ultra performance liquid chromatography; 22.5% and 41.3% of samples were positive, with total aflatoxin concentrations of 786 and 3135 ng g⁻¹ from 2013/2014 and 2014/2015 …

Expression Of Apoplast-Targeted Plant Defensin Mtdef4.2 Confers Resistance To Leaf Rust Pathogen Puccinia Triticina But Does Not Affect Mycorrhizal Symbiosis In Transgenic Wheat, Jagdeep Kaur, John Fellers, Alok Adholeya, Siva L.S. Velivelli, Kaoutar El-Mounadi, Natalya Nersesian, Thomas Clemente, Dilip Shah

Department of Agronomy and Horticulture: Faculty Publications

Rust fungi of the order Pucciniales are destructive pathogens of wheat worldwide. Leaf rust caused by the obligate, biotrophic basidiomycete fungus Puccinia triticina (Pt) is an economically important disease capable of causing up to 50 % yield losses. Historically, resistant wheat cultivars have been used to control leaf rust, but genetic resistance is ephemeral and breaks down with the emergence of new virulent Pt races. There is a need to develop alternative measures for control of leaf rust in wheat. Development of transgenic wheat expressing an antifungal defensin offers a promising approach to complement the endogenous resistance genes …

Letter From The Dean, Lona Robertson

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

No abstract provided.

Message From The Faculty Editor, Mary Savin

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.

Comprehensive Comparative Genomic And Transcriptomic Analyses Of The Legume Genes Controlling The Nodulation Process, Zhenzhen Qiao, Lise Pingault, Mehrnoush Nourbakhsh-Rey, Marc Libault

Department of Agronomy and Horticulture: Faculty Publications

Nitrogen is one of the most essential plant nutrients and one of the major factors limiting crop productivity. Having the goal to perform a more sustainable agriculture, there is a need to maximize biological nitrogen fixation, a feature of legumes. To enhance our understanding of the molecular mechanisms controlling the interaction between legumes and rhizobia, the symbiotic partner fixing and assimilating the atmospheric nitrogen for the plant, researchers took advantage of genetic and genomic resources developed across different legume models (e.g., Medicago truncatula, Lotus japonicus, Glycine max, and Phaseolus vulgaris) to identify key regulatory protein coding genes of the nodulation …

Comparison Of An Ultra-Low Volume (Ulv) Sprayer Against A Conventional Sprayer, For Foliar Fertiliser And Fungicide Applications In Turfgrass, Jason Connor Ferguson, Roch E. Gaussoin, John A. Eastin, Matthew D. Sousek, Greg R. Kruger

Department of Agronomy and Horticulture: Faculty Publications

Two field studies (I and II) at the University of Nebraska-Lincoln: John Seaton Anderson Turfgrass Research Facility near Mead, NE, USA, were conducted to determine if a new ultra-low volume (ULV) sprayer can apply foliar nutrient, growth regulator, and fungicide treatments, in a manner similar to that of a conventional sprayer. Treatments were applied over creeping bentgrass ‘L-93’ (Agrostis stolonifera L.) managed as a fairway at 561 l · ha⁻¹ and 47 l · ha⁻¹ with the conventional and ULV sprayer, respectfully. Data were collected for chlorophyll content with a chlorophyll meter, and for the normalised difference …

Proteomic Profiling Of Maize Opaque Endosperm Mutants Reveals Selective Accumulation Of Lysine-Enriched Proteins, Kyla J. Morton, Shangang Jia, Chi Zhang, David R. Holding

Department of Agronomy and Horticulture: Faculty Publications

Reduced prolamin (zein) accumulation and defective endoplasmic reticulum (ER) body formation occurs in maize opaque endosperm mutants opaque2 (o2), floury2 (fl2), defective endosperm*B30 (DeB30), and Mucronate (Mc), whereas other opaque mutants such as opaque1 (o1) and floury1 (fl1) are normal in these regards. This suggests that other factors contribute to kernel texture. A liquid chromatography approach coupled with tandem mass spectrometry (LC-MS/MS) proteomics was used to compare non-zein proteins of nearly isogenic opaque endosperm mutants. In total, 2762 proteins were identified that were enriched for biological processes such …

Horizontal Gene Acquisitions, Mobile Element Proliferation, And Genome Decay In The Host-Restricted Plant Pathogen Erwinia Tracheiphila, Lori R. Shapiro, Erin D. Scully, Timonthy J. Straub, Jihye Park, Andrew G. Stephenson, Gwyn A. Beattie, Mark L. Gleason, Roberto Kolter, Miguel C. Coelho, Consuelo M. De Moraes, Mark C. Mescher, Olga Zhaxybayeva

Department of Agronomy and Horticulture: Faculty Publications

Modern industrial agriculture depends on high-density cultivation of genetically similar crop plants, creating favorable conditions for the emergence of novel pathogens with increased fitness in managed compared with ecologically intact settings. Here, we present the genome sequence of six strains of the cucurbit bacterial wilt pathogen Erwinia tracheiphila (Enterobacteriaceae) isolated from infected squash plants in New York, Pennsylvania, Kentucky, and Michigan. These genomes exhibit a high proportion of recent horizontal gene acquisitions, invasion and remarkable amplification of mobile genetic elements, and pseudogenization of approximately 20% of the coding sequences. These genome attributes indicate that E. tracheiphila recently emerged as a …

Nutrients In The Nexus, Eric A. Davidson, Rachel L. Nifong, Richard B. Ferguson, Cheryl Palm, Deanna L. Osmond, Jill S. Baron

Department of Agronomy and Horticulture: Faculty Publications

Synthetic nitrogen (N) fertilizer has enabled modern agriculture to greatly improve human nutrition during the twentieth century, but it has also created unintended human health and environmental pollution challenges for the twentyfirst century. Averaged globally, about half of the fertilizer-N applied to farms is removed with the crops, while the other half remains in the soil or is lost from farmers’ fields, resulting in water and air pollution. As human population continues to grow and food security improves in the developing world, the dual development goals of producing more nutritious food with low pollution will require both technological and socioeconomic …

Alkaline Stress And Iron Deficiency Regulate Iron Uptake And Riboflavin Synthesis Gene Expression Differently In Root And Leaf Tissue: Implications For Iron Deficiency Chlorosis, En-Jung Hsieh, Brian M. Waters

Department of Agronomy and Horticulture: Faculty Publications

Iron (Fe) is an essential mineral that has low solubility in alkaline soils, where its deficiency results in chlorosis. Whether low Fe supply and alkaline pH stress are equivalent is unclear, as they have not been treated as separate variables in molecular physiological studies. Additionally, molecular responses to these stresses have not been studied in leaf and root tissues simultaneously. We tested how plants with the Strategy I Fe uptake system respond to Fe deficiency at mildly acidic and alkaline pH by measuring root ferric chelate reductase (FCR) activity and expression of selected Fe uptake genes and riboflavin synthesis genes. …

Corn Response To Nitrogen Management Under Fully-Irrigated Vs. Water-Stressed Conditions, Bijesh Maharjan, Carl J. Rosen, John A. Lamb, Rodney T. Venterea

Department of Agronomy and Horticulture: Faculty Publications

Characterizing corn (Zea mays L.) grain yield (GY) response to N is critical for maximizing profits, increasing N use efficiency and minimizing environmental impacts. Although a large database of GY response to N exists for highly productive soils, few data exist for less productive soils. While changes in precipitation are expected in the future, few studies have compared GY response to varying N management practices under conditions of varying water availability. We measured GY and basal stalk nitrate nitrogen (BSN) at harvest using split-applied urea at eight N rates under fully-irrigated (FI) and water-stressed (WS) conditions in a loamy …

Letter To The Editor Ws-2 Introgression In A Proportion Of Arabidopsis Thaliana Col-0 Stock Seed Produces Specific Phenotypes And Highlights The Importance Of Routine Genetic Verification, Mon-Ray Shao, Vikas Shedge, Hardik Kundariya, Fredric R. Lehle, Sally Ann Mackenzie

Department of Agronomy and Horticulture: Faculty Publications

Arabidopsis thaliana is an important model organism with a robust network of resources that has been of enormous value to the plant science research community. The use of isogenic material as a reference point or control is critical for many types of experiments in plant molecular biology and genetics. Recently, we noticed that some seed from a common source of the widely-used Columbia-0 (Col-0) strain gave rise to plants showing features atypical for this strain. Whole genome DNA-sequencing and allele-specific PCR assays confirmed that the abnormal individuals contain multiple introgressions from the ecotype Wassilewskija-2 (Ws-2), as described below. This emphasizes …

Distribution And Characterization Of The Soybean Cyst Nematode, Heterodera Glycines (Hg) Types In South Dakota, Krishna Acharya

Electronic Theses and Dissertations

The soybean cyst nematode (SCN), Heterodera glycines Ichinohe, is an endoparasitic nematode and one of the major pests of soybean (Glycine max L.) in the United State and all over the world where soybean is grown. SCN is ranked first among the biological factors that cause yield loss in soybean. The estimated yield loss by this nematode is $1b annually in the United States alone. SCN is thought to have been first found in China. It was first identified in the United States in 1954 in North Carolina and in South Dakota in 1995. To date, SCN continues to spread …

Extension Agriculture And Natural Resources In The U.S. Midwest: A Review And Analysis Of Challenges And Future Opportunities, Mahdi M. Al-Kaisi, Roger Wesley Elmore, Gerald A. Miller, David Kwaw-Mensah

Department of Agronomy and Horticulture: Faculty Publications

This review addresses key changes in U.S. agricultural extension and future opportunities. Agricultural extension has been a part of the land-grant university (LGU) system for more than 100 years. The Morrill Act of 1862 established the LGU system by authorizing states access to federally controlled land and funding for public institutions offering educational opportunities focusing on agriculture and mechanical arts for farmers and the working class. Current surveys in Iowa reveal changing trends in extension: more than 90% of farmers identified private-sector crop advisers as their primary source for recommendations, whereas more than 80% of those advisors identified Iowa State …

Assessing Foliar Ascorbate Content In A Rice Diversity Panel And In Selected Mapping Population Lines With Varying Levels Of Seedling Cold Tolerance, Sonia Elizabeth Castillo Gonzalez

Student Theses and Dissertations

Rice is economically, culturally, and socially important to many people in the world. Arkansas is the main rice producer in the USA. Climate change continues to increase the incidence of abiotic stresses such as cold, heat, drought, water excess, and soil salinity. These stresses pose a particular challenge to rice cultivation. Rice has lower yields under cold stress, particularly when plants are exposed to cold at the seedling and reproductive stages. Early spring plantings and field irrigation with underground cold water expose rice seedlings to cold stress. Previous studies in Arabidopsis thaliana have shown that lines engineered to have elevated …

Molecular Genetic Aspects Of Iron And Copper Cross-Talk In Arabidopsis Thaliana, Qingyuan Xiang

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

Iron (Fe) and copper (Cu) are essential micronutrients for plants and humans who consume plants. Their functions are tightly linked. For example, both of Fe and Cu work as cofactors in superoxide dismutase proteins to prevent reactive oxygen species damage. When Fe is removed from nutrient solution, plants uptake more Cu, but how plants sense and respond to Fe status is not fully understood. This thesis includes two projects that focus on Fe and Cu interaction, homeostasis and cross-talk in Arabidopsis thaliana.

Two Arabidopsis ecotypes, Kas-1 and Tsu-1, have difference in timing of Cu accumulation in rosettes under Fe …