Agricultural Science Commons^™

Functional Characterization Of Petiolule-Like Pulvinus (Plp) Gene In Abscission Zone Development In Medicago Truncatula And Its Application To Genetic Improvement Of Alfalfa, Juan Du, Shaoyun Lu, Maofeng Chai, Chuanen Zhou, Liang Sun, Yuhong Tang, Jaydeep Kolape, Zhaozhu Wen, Marjan Behzadirad, Tianxiu Zhong, Juan Sun, Yunwei Zhang, Zeng-Yu Wang

Department of Agronomy and Horticulture: Faculty Publications

Alfalfa (Medicago sativa L.) is one of the most important forage crops throughout the world. Maximizing leaf retention during the haymaking process is critical for achieving superior hay quality and maintaining biomass yield. Leaf abscission process affects leaf retention. Previous studies have largely focused on the molecular mechanisms of floral organ, pedicel and seed abscission but scarcely touched on leaf and petiole abscission. This study focuses on leaf and petiole abscission in the model legume Medicago truncatula and its closely related commercial species alfalfa. By analysing the petiolule-like pulvinus (plp) mutant in M. truncatula at phenotypic level (breakstrength and shaking …

Food System And Water–Energy–Biodiversity Nexus In Nepal: A Review, Roshan Subedi, Madhav Karki, Dinesh Panday

Department of Agronomy and Horticulture: Faculty Publications

Water, energy, and biodiversity are essential components for building a sustainable food system in a developing country like Nepal. Green Revolution technologies and the package of practices largely ignored the role of ecosystem services, leaving a large population of small farmers’ food- and nutrition-insecure. Biodiversity, especially, agrobiodiversity is in decline and this vital cross-cutting element is less discussed and interlinked in nexus literature. The interlinking food system with water–energy–biodiversity nexus, therefore, is essential to achieve a resilient food system. It ensures the vital structures and functions of the ecosystem on which it is dependent are well protected in the face …

Effects Of Char On Nitrogen Management In Agricultural Soils Of Semi-Arid Western Nebraska, Dinesh Panday

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

Soils in western Nebraska are characterized by low soil organic C due to semi-arid environment in the region and further aggravated by disruption of soil aggregates and rapid C decomposition from intensive tillage, erosion, and frequent droughts. Proper management of soil C may improve soil properties, reduce N losses, and subsequently improve crop yields in this low C soil and low moisture condition. This dissertation focuses on C-rich coal char (henceforth “char”) as a potential strategy to overcome the existing problem of low C in semi-arid region. Char is an industrial by-product, resulting from inefficient coal burning during sugar beet …

Influence Of Cover Crop Management Practices On Rainfed Corn Production In Semi-Arid Western Nebraska, Alexandre Tonon Rosa

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

With the increased cover crop (CC) popularity, producers of semi-arid regions of western Nebraska are questioning whether they could successfully incorporate CC into their rainfed winter wheat (Triticum aestivum L.)-corn (Zea mays L.)-fallow rotations. The major concern is that CCs may deplete soil water affecting the subsequent crop. Therefore, three studies were established under rainfed conditions of western Nebraska to access the effects of CCs on soil water, soil compaction, nutrient cycling, weed demographics, residue coverage, and subsequent corn yield. The first study evaluated the influence of CC planting and termination times prior to corn establishment. Late termination …

Description Of Baetao-Manteiga 41 And ‘Yunguilla’ Superior Andean Common Beans For Tanzanian Production Environments, S. Nchimbi Msolla, Phillip N. Miklas, D. Fourie, M. Kilango, T. Porch

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

An international effort was initiated with the evaluation of a diverse set of largeseeded Andean common beans (Phaseolus vulgaris L.), the Andean Diversity Panel, in sub-Saharan Africa. Several entries in the panel have been selected for extensive characterization on the basis of high performance acrossmultiple location × year trials in Tanzania—conducted both on station and on farm. Baetao- Manteiga 41, tested asADP-190, has a commercialKablanketi (light purple speckled) seed type, and ‘Yunguilla’, tested as ADP-447, has a commercial Calima (red mottled) seed type. Both lines exhibited yield stability, vigorous growth under low fertility conditions, angular leaf spot resistance, andmoderate …

Perioperative And Oncological Outcomes Following Minimally Invasive Versus Open Pancreaticoduodenectomy For Pancreatic Duct Adenocarcinoma, Rui Sun, Jiawen Yu, Yifan Zhang

Department of Agronomy and Horticulture: Faculty Publications

Background The outcomes of minimally invasive pancreaticoduodenectomy have not been adequately compared with those of open pancreaticoduodenectomy in patients with pancreatic ductal adenocarcinoma. We performed a meta‐analysis to compare the perioperative and oncological outcomes of these two pancreaticoduodenectomy procedures specifically in patients with pancreatic ductal adenocarcinoma.

Methods Before this study was initiated, a specific protocol was designed and has been registered in PROSEPRO (ID: CRD42020149438). Using the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines, PubMed, EMBASE, Web of Science, Cochrane Central Register, and ClinicalTrials.gov databases were systematically searched for studies published between January 1994 and October 2019. …

Evaluating Opportunities For Integrated Crop Livestock Systems In Eastern Nebraska, Elizabeth Kay Christenson

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

Current agricultural systems focused on production of few commodities are facing production, economic, and environmental challenges. To address these challenges, Integrated Crop Livestock Systems (ICLS) have emerged through three primary methods 1) perennial grasslands for grazing and/or hay production, 2) crop residue grazing, and 3) cover crop grazing. To evaluate potential of ICLS mitigating current challenges, a field scale model ICLS was developed in 2015. The ICLS includes 4-ha each of ‘Newell’ smooth bromegrass (Bromus inermis L.), ‘Liberty’ switchgrass (Panicum virgatum L.), and ‘Shawnee’ switchgrass. The ICLS also included 8-ha of continuous corn (Zea mays L.). In …

Soil-Nitrogen, Potentially Mineralizable-Nitrogen, And Field Condition Information Marginally Improves Corn Nitrogen Management, Jason Clark, Fabián G. Fernández, Kristen S. Veum, James J. Camberato, Paul R. Carter, Richard Ferguson, David W. Franzen, Daniel E. Kaiser, Newell R. Kitchen, Carrie A.M. Laboski, Emerson Nafziger, Carl J. Rosen, John E. Sawyer, John F. Shanahan

Department of Agronomy and Horticulture: Faculty Publications

Anaerobic potentially mineralizable nitrogen (PMN) combined with preplant nitrate test (PPNT) or pre-sidedress nitrate test (PSNT) may improve corn (Zea mays L.) N management. Forty-nine corn N response studies were conducted across the U.S. Midwest to evaluate the capacity of PPNT and PSNT to predict grain yield, N uptake, and economic optimal N rate (EONR) when adjusted by soil sampling depth, soil texture, temperature, PMN, and initial NH₄–N from PMN analysis. Pre-plant soil samples were obtained for PPNT (0- to 30-, 30- to 60-, 60- to 90-cm depths) and PMN (0- to 30-cm depth) before corn planting …

A Survey Of Dairy-Goat Keeping In Zanzibar, Tiffanie Stone, Charles A. Francis, L. O. Eik

Department of Agronomy and Horticulture: Faculty Publications

Dairy goats with improved genetics for milk production were recently introduced onto small-scale farms in Zanzibar through governmental and non-governmental projects. These projects were meant to support small-scale farmers by improving both income and household nutrition through milk production. No follow up had been conducted to understand what effects dairy goat keeping had on these small-scale farms, or how they could be improved. A survey of 193 dairy goat farmers in Zanzibar was conducted, including 30% and 60% of all dairy goat farmers on Unguja and Pemba, the two largest islands, respectively. The objective was to understand the impact keeping …

Effects Of Pyric Herbivory On Prairie-Chicken (Tympanuchus Spp) Habitat, Heath D. Starns, Samuel D. Fuhlendorf, Robert D. Elmore, Dirac Twidwell, Eric T. Thacker, Torre J. Hovick, Barney Luttbeg

Department of Agronomy and Horticulture: Faculty Publications

The reduction and simplification of grasslands has led to the decline of numerous species of grassland fauna, particularly grassland-obligate birds. Prairie-chickens (Tympanuchus spp.) are an example of obligate grassland birds that have declined throughout most of their distribution and are species of conservation concern. Pyric herbivory has been suggested as a land management strategy for enhancing prairie-chicken habitat and stabilizing declining population trends. We assessed differences in vegetation structure created by pyric herbivory compared to fire-only treatments to determine whether pyric herbivory increased habitat heterogeneity for prairie-chickens, spatially or temporally. Our study was performed at four sites in the southern …

Utilizing Annual Forage Crops In Rotations, John Hewlett, Jay Parsons, Jeff Tranel

Extension Farm and Ranch Management News

First paragraph

Approximately 60 million acres of forage are harvested annually in the United States, according to the National Agricultural Statistical Service (NASS). With lower commodity grain and oilseed prices along with high pasture rental rates and/or difficulty finding range and pasture to rent, some producers are considering ways to incorporate more forages into their crop rotations.

Production And Selection Of Quality Protein Popcorn Hybrids Using A Novel Ranking System And Combining Ability Estimates, Leandra Parsons, Ying Ren, Abou Yobi, Preston Hurst, Ruthie Angelovici, Oscar Rodriguez, David R. Holding

Department of Agronomy and Horticulture: Faculty Publications

Popcorn varieties are agronomically sub-optimal and genetically limited compared to other maize subspecies. To increase genetic diversity and improve popcorn agronomics, dent germplasm has been introduced to popcorn with limited success and generally, major loss of popping. Between 2013 and 2018, 12 Quality Protein Popcorn (QPP) inbreds containing Quality Protein Maize (QPM) and popcorn germplasm were produced that maintained popping while carrying the opaque-2 allele conferring elevated kernel lysine. This is an opportune trait in the growing market for healthier snacks and a model for mining QPM traits into popcorn. We crossed QPP inbreds to explore the effects of heterosis …

Genomic Prediction Enhanced Sparse Testing For Multi-Environment Trials, Diego Jarquin, Reka Howard, José Crossa, Yoseph Beyene, Manje Gowda, Johannes W.R. Martini, Giovanny Covarrubias Pazaran, Juan Burgueño, Angela Pacheco, Martin Grondona, Valentin Wimmer, Boddupalli M. Prasanna

Department of Agronomy and Horticulture: Faculty Publications

“Sparse testing” refers to reduced multi-environment breeding trials in which not all genotypes of interest are grown in each environment. Using genomic-enabled prediction and a model embracing genotype · environment interaction (GE), the non-observed genotype-in-environment combinations can be predicted. Consequently, the overall costs can be reduced and the testing capacities can be increased. The accuracy of predicting the unobserved data depends on different factors including (1) how many genotypes overlap between environments, (2) in how many environments each genotype is grown, and (3) which prediction method is used. In this research, we studied the predictive ability obtained when using a …

Effects Of Tank Contamination And Impact Of Drift-Reducing Agents On Weed Control In Response To Dicamba Applications, Milos Zaric

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

Availability of dicamba-tolerant (DT) crops from 2017 provided farmers with additional herbicides for weed control management in row crops. However, the technology alike this one has concerns regarding dicamba off-target movement (OTM) causing undesirable effects on sensitive vegetation. Even though dicamba has high water solubility OTM that has often been overlooked when it comes to unintended crop exposure is dicamba tank contamination. Considering the complexity of spraying equipment soybean response may be expected even when small amounts of residues are left in the spray equipment. Typically, the same field spray equipment is used to perform herbicide application through growing season …

Irrigation, Carbon Amelioration, Nitrogen, And Stover Removal Effects On Continuous Corn, Marty Schmer, Virginia L. Jin, Richard B. Ferguson, Brian J. Wienhold

Department of Agronomy and Horticulture: Faculty Publications

Corn (Zea mays L.) residue or stover is harvested as supplemental feed for livestock and is a potential feedstock for cellulosic biofuels. Limited information is available on corn stover removal effects on grain yield under different irrigation rates, nitrogen (N) fertilizer rates, and practices to maintain soil carbon (C) and minimize soil erosion. We evaluated potential interactions between irrigation rate (full or limited), C amelioration practices (cover crop, surface-applied manure, or no amelioration practice), fertilizer N management (125 or 200 kg N ha⁻¹), and stover removal (residue removal or no residue removal), on no-till continuous corn …

Weed Control Efficacy Of Bio-Based Sprayable Mulch Films In Specialty Crop Systems, Eliott Gloeb

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

A sprayable bio-based mulch film (biofilm) could present a more sustainable weed management tool for specialty crop producers than conventional plastic mulch films while also offering flexibility in application patterns and timing. From 2017 to 2019, six greenhouse trials and four field trials were conducted at the University of Nebraska-Lincoln to study the effects of biofilm application on weed suppression and crop yields. Multiple application rates (0.81 L/m² - 9.78 L/m²) and application times (prior to weed emergence and post weed emergence) were tested. Corn starch, glycerol, keratin hydrolysate, corn gluten meal, corn zein, and isolated soy …

Characterizing Variation In Nitrogen Use Efficiency In Wheat Genotypes Using Proximal Canopy Sensing For Sustainable Wheat Production, Mohammed A. Naser, Raj Khosla, Louis Longchamps, Subash Dahal

Department of Agronomy and Horticulture: Faculty Publications

Global nitrogen use efficiency (NUE) for cereal production is marginal and is estimated to be about 33%. Remote sensing tools have tremendous potential for improving NUE in crops through efficient nitrogen management as well as the identification of high-NUE genotypes. The objectives of this study were (i) to identify and quantify the variation in NUE across 24 winter wheat genotypes (Triticum aestivum L.) and (ii) to determine if the normalized difference vegetation index (NDVI) could characterize the variability in NUE across wheat genotypes. This study was conducted in 2010 and 2011 in the semi-arid climate of Northeastern Colorado across dryland …

Genome Wide Association Study Reveals Plant Loci Controlling Heritability Of The Rhizosphere Microbiome, Siwen Deng, Daniel F. Caddell, Gen Xu, Lindsay Dahlen, Lorenzo Washington, Jinliang Yang, Devin Coleman-Derr

Department of Agronomy and Horticulture: Faculty Publications

Host genetics has recently been shown to be a driver of plant microbiome composition. However, identifying the underlying genetic loci controlling microbial selection remains challenging. Genome-wide association studies (GWAS) represent a potentially powerful, unbiased method to identify microbes sensitive to the host genotype and to connect them with the genetic loci that influence their colonization. Here, we conducted a population-level microbiome analysis of the rhizospheres of 200 sorghum genotypes. Using 16S rRNA amplicon sequencing, we identify rhizosphere-associated bacteria exhibiting heritable associations with plant genotype, and identify significant overlap between these lineages and heritable taxa recently identified in maize. Furthermore, we …

Assessing Approaches For Stratifying Producer Fields Based On Biophysical Attributes For Regional Yield-Gap Analysis, Spyridon Mourtzinis, Patricio Grassini, Juan I. Rattalino Edreira, José F. Andrade, Peter M. Kyveryga, Shawn P. Conley

Department of Agronomy and Horticulture: Faculty Publications

Large databases containing producer field-level yield and management records can be used to identify causes of yield gaps. A relevant question is how to account for the diverse biophysical background (i.e., climate and soil) across fields and years, which can confound the effect of a given management practice on yield. Here we evaluated two approaches to group producer fields based on biophysical attributes: (i) a technology extrapolation domain spatial framework (‘TEDs’) that delineates regions with similar (long-term average) annual weather and soil water storage capacity and (ii) clusters based on field-specific soil properties and weather during each crop …

Resilience To Large, “Catastrophic” Wildfires In North America's Grassland Biome, Victoria M. Donovan, Dirac Twidwell, Daniel R. Uden, Tsegaye Tadesse, Brian D. Wardlow, Christine H. Bielski, Matthew O. Jones, Brady W. Allred, David E. Naugle, Craig R. Allen

Department of Agronomy and Horticulture: Faculty Publications

Wildfires are ecosystem‐level drivers of structure and function in many vegetated biomes. While numerous studies have emphasized the benefits of fire to ecosystems, large wildfires have also been associated with the loss of ecosystem services and shifts in vegetation abundance. The size and number of wildfires are increasing across a number of regions, and yet the outcomes of large wildfire on vegetation at large‐scales are still largely unknown. We introduce an exhaustive analysis of wildfire‐scale vegetation response to large wildfires across North America's grassland biome. We use 18 years of a newly released vegetation data set combined with 1,390 geospatial …

Control Of Volunteer Corn In Enlist Corn And Economics Of Herbicide Programs For Weed Control In Conventional And Multiple Herbicide-Resistant Soybean Across Nebraska, Adam Michael Striegel

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

With commercialization of multiple herbicide-resistant corn and soybean cultivars, producers have new management options for controlling herbicide-resistant weeds and volunteer corn. Corn-on-corn production systems are common in irrigated fields in southcentral Nebraska which can create issues with volunteer corn management in corn fields. Enlist corn contains a new multiple herbicide-resistant trait providing resistance to 2,4-D choline, glyphosate, and the aryloxyphenoxypropionate (FOPs). Field experiments were conducted in 2018 and 2019 at South Central Agricultural Laboratory near Clay Center, Nebraska with the objective to evaluate ACCase-inhibiting herbicides and herbicide application timing on volunteer corn control, Enlist corn injury, and yield. Glyphosate/glufosinate-resistant corn …

Buffalograss Diversity Assessment, Jesse Collin Marshall

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

Buffalograss [Buchloë dactylodes (Nutt.) Engelm. syn. Bouteloua dactyloides (Nutt.) Columbus] is a low input alternative turfgrass for the Great Plains region. Buffalograss is a dioecious stoloniferous warm season grass with wide variation of valuable traits and is well adapted for use in minimal maintenance landscapes. The obligate outcrossing nature of the species and wide variation of potentially valuable traits make buffalograss a prime candidate for cultivar improvement and genetic study. Limited information is available regarding buffalograss genetics. In effort to expand genetic resources around buffalograss, we developed buffalograss derived simple sequence repeat markers from previously available transcriptomes of buffalograss …

Impact Of Agricultural Land Use On Stream Nitrate, Phosphorus, And Sediment Concentrations At The Watershed And Field Scale, Brittany A. Kirsch

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

Water quality is directly impacted by the landscape through which it travels. As such, land use, including summer annual and winter annual/perennial agriculture, has dramatic influence on the water quality of downstream aquatic and terrestrial ecosystems. I examined the impact of agricultural land use on water quality through two projects, one at a watershed scale and one at a field scale. In my first project, I investigated the impact of agricultural land use and climate on water quality in 13 HUC10 watersheds across Nebraska using public data from US Geological Survey (USGS), US Department of Agriculture National Agricultural Statistics Service …

Remediation Strategies To Reduce Heavy Metal Uptake In Lettuce Grown In Contaminated Urban Soil, Ryley Thomas

UCARE: Research Products

Urban soils are increasingly used to produce food for local consumption, which requires at the same time management strategies that prevent the plant uptake of potentially present contaminants. This study was conducted to test different soil amendments for their ability to retain lead (Pb) and arsenic (As) within the soil matrix. The analyzed soil was taken from a potential community garden lot near a railroad in Lincoln, NE where elevated concentrations in Pb and As had been detected. Ponderosa pine biochar and spent coffee grounds were used as soil additives because of their documented chemical reactivity towards soil cations or …

Fungicide Sensitivity Of Sclerotinia Sclerotiorum Isolates From Five States With Different Fungicide Treatments, Cristian Wulkop Gil, Edgar Nieto-Lopez, Sydney Everhart

UCARE: Research Products

Sclerotinia sclerotiorum is a plant pathogenic fungus that causes a disease called white mold that can infect more than 450 plant species including soybeans, dry beans, green beans, canola, and sunflower. This pathogen is capable of up to $252M in losses every year (U.S. Canola Association, 2014). Fungicides are widely used in developed agricultural systems to control disease. However, resistance to the most effective fungicides has emerged and spread in pathogen populations and there have been multiple reports of S. sclerotiorum isolates becoming resistant to certain fungicides. Since different fields in different states use different fungicide treatments on plants and …

Reaction Of Tepary Beans To Eight Virulent Races Of The Rust Pathogen That Overcomes All Known Common Bean Rust Resistance Genes, Santos Barrera Lemus, Prabin Tamang, Carlos A. Urrea, Marcial A. Pastor-Corrales

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

Bean rust, caused by Uromyces appendiculatus, is a major disease of common and snap bean (Phaseolus vulgaris) worldwide (Stavely, 1984). Although host resistance is an important component of rust management (Mmbaga et al., 1996), populations of the rust pathogen comprise an extensive and shifting virulence diversity that could render susceptible all known rust resistance genes in common bean. Conversely, it has been suggested that certain tepary bean (Phaseolus acutifolius) accessions are broadly resistant to bean rust (Miklas & Stavely, 1998). The objectives of this study were to verify if tepary beans are resistant to …

Extreme Fire As A Management Tool To Combat Regime Shifts In The Range Of The Endangered American Burying Beetle, Alison K. Ludwig, Daniel R. Uden, Dirac Twidwell

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

This study is focused on the population of federally-endangered American burying beetles in south-central Nebraska. It is focused on changes in land cover over time and at several levels of spatial scale, and how management efforts are impacting both the beetle and a changing landscape. Our findings are applicable to a large portion of the Great Plains, which is undergoing the same shift from grassland to woodland, and to areas where the beetle is still found.

Variance Heterogeneity Genome-Wide Mapping For Cadmium In Bread Wheat Reveals Novel Genomic Loci And Epistatic Interactions, Waseem Hussain, Malachy T. Campbell, Diego Jarquin, Harkamal Walia, Gota Morota

Department of Agronomy and Horticulture: Faculty Publications

Genome-wide association mapping identifies quantitative trait loci (QTL) that influence the mean differences between the marker genotypes for a given trait. While most loci influence the mean value of a trait, certain loci, known as variance heterogeneity QTL (vQTL) determine the variability of the trait instead of the mean trait value (mQTL). In the present study, we performed a variance heterogeneity genome-wide association study (vGWAS) for grain cadmium (Cd) concentration in bread wheat. We used double generalized linear model and hierarchical generalized linear model to identify vQTL associated with grain Cd. We identified novel vQTL regions on chromosomes 2A and …

Fungicide Sensitivity Of Sclerotinia Sclerotiorum Isolates Selected From Five Different States That Use Different Fungicide Treatments, Cristian Wulkop Gil

UCARE: Research Products

Sclerotinia sclerotiorum is a plant pathogenic fungus that causes a disease called white mold that can infect more than 450 plant species including soybeans, dry beans, green beans, canola, and sunflower. This pathogen is capable of up to $252M in losses every year (U.S. Canola Association, 2014). Fungicides are widely used in developed agricultural systems to control disease. However, resistance to the most effective fungicides has emerged and spread in pathogen populations and there have been multiple reports of S. sclerotiorum isolates becoming resistant to certain fungicides. Since different fields in different states use different fungicide treatments on plants and …

A Global Perspective On Sustainable Intensification Research, Kenneth Cassman, Patricio Grassini

Department of Agronomy and Horticulture: Faculty Publications

Despite general agreement that meeting food demand without further loss of natural ecosystems requires sustainable intensification, there is little dialogue about the research agenda needed to achieve it. To that end, we evaluate current trajectories towards sustainable intensification, review published research on the topic, identify missing links, and propose a prioritization framework to fill gaps. Although progress towards sustainable intensification is behind schedule, we are optimistic that current trends can get back on course assuming a well-prioritized and adequately funded research portfolio and appropriate policies and institutions to support it.