Agricultural Science Commons^™

Pollen-Mediated Gene Flow From Herbicide-Resistant Yellow Corn To Non-Genetically Engineered Food-Grade White Corn, Mandeep Singh, Vipan Kumar, Stevan Z. Knezevic, John L. Lindquist, Suat Irmak, Santosh Pitla, Amit J. Jhala

Department of Agronomy and Horticulture: Faculty Publications

Nebraska is the number one producer of food-grade white corn in the United States. Pollen-mediated gene flow (PMGF) from genetically engineered high alpha-amylase corn, known as Enogen corn, to food-grade white corn can have undesirable outcomes. Alpha-amylase can convert starch in white corn to sugar during or after its processing, degrading the quality of processed products. Thus, proximity to Enogen corn puts white corn production at risk. The objectives of this study were to evaluate the PMGF from herbicide-resistant yellow corn to food-grade white corn and assess the significance of wind speed and direction. Field experiments were set up using …

Leveraging Digital Agriculture For On-Farm Testing Of Technologies, Laila A. Puntel, Laura J. Thompson, Taro Mieno

Department of Agronomy and Horticulture: Faculty Publications

The Precision Nitrogen Project (PNP) worked with more than 80 corn and winter wheat producers to inexpensively design and implement randomized, replicated field strip trials on whole commercial farm fields, and to provide site-specific testing of current nitrogen (N) technologies. This article proposes a conceptual framework and detailed procedure to select the N technology to be tested; design and implement field trials; generate, process, and manage field trial data; and automatically analyze, report, and share benefits from precision N technology. The selection of the N technology was farmer-driven to ensure a good fit and to increase the likelihood of future …

Variation In Leaf Chlorophyll Concentration In Response To Nitrogen Application Across Maize Hybrids In Contrasting Environments, Kyle M. Linders, Dipak K. Santra, James C. Schnable, Brandi Sigmon

Department of Agronomy and Horticulture: Faculty Publications

Leaf chlorophyll concentration was measured for 84 publicly available maize hybrids grown under three nitrogen fertilizer treatments in two contrasting environments in Nebraska. The effect of nitrogen treatment on chlorophyll response was found to be significant (p < 0.05) for both locations. In Scottsbluff, chlorophyll concentrations increased significantly with increasing nitrogen rate, while no significant difference was found between medium and high nitrogen in Lincoln. Within equivalent nitrogen treatments, chlorophyll was more abundant in Lincoln than Scottsbluff for nearly every hybrid. Hybrid response was not consistent between environments, with approximately 11% of variance explained by genotype by environment interaction.

Calibration Of Hybrid-Maize Model For Simulation Of Soil Moisture And Yield In Production Corn Fields, Anthony A. Amori, Olufemi P. Abimbola, Trenton E. Franz, Daran Rudnick, Javed Iqbal, Haishun Yang

Department of Agronomy and Horticulture: Faculty Publications

Model calibration is essential for acceptable model performance and applications. The Hybrid-Maize model, developed at the University of Nebraska-Lincoln, is a process-based crop simulation model that simulates maize growth as a function of crop and field management and environmental conditions. In this study, we calibrated and validated the Hybrid-Maize model using soil moisture and yield data from eight commercial production fields in two years. We used a new method for the calibration and multi-parameter optimization (MPO) based on kriging with modified criteria for selecting the parameter combinations. The soil moisture-related parameter combination (SM-PC3) improved simulations of soil water dynamics, but …

U.S. Cereal Rye Winter Cover Crop Growth Database, Alexandra M. Huddell, Resham Thapa, Guillermo S. Marcillo, Lori J. Abendroth, Victoria J. Ackroyd, Shalamar D. Armstrong, Gautam Asmita, Muthukumar V. Bagavathiannan, Kipling S. Balkcom, Andrea Basche, Shawn Beam, Kevin Bradley, Lucas Pecci Canisares, Heather Darby, Adam S. Davis, Pratap Devkota, Warren A. Dick, Jeffery A. Evans, Wesley J. Everman, Tauana Ferreira De A Lmeida, Michael L. Flessner, Lisa M. Fultz, Stefan Gailans, Masoud Hashemi, Joseph Haymaker, Matthew J. Helmers, Nicholas Jordan, Thomas C. Kaspar, Quirine M. Ketterings, Eileen Kladivko, Alexandra Kravchenko, Eugene P. Law, Lauren Lazaro, Ramon G. Leon, Jeffrey Liebert, John Lindquist, Kristen Loria, Jodie M. Mcvane, Jarrod O. Miller, Michael J. Mulvaney, Nsalambi V. Nkongolo, Jason K. Norsworthy, Binaya Parajuli, Christopher Pelzer, Cara Peterson, Hanna Poffenbarger, Pratima Poudel, Mark S. Reiter, Matt Ruark, Matthew R. Ryan, Spencer Samuelson, John E. Sawyer, Sarah Seehaver, Lovreet S. Shergill, Yogendra Raj Upadhyaya, Mark Vangessel, Ashley L. Waggoner, John M. Wallace, Samantha Wells, Charles White, Bethany Wolters, Alex Woodley, Rongzhong Ye, Eric Youngerman, Brian A. Needelman, Steven B. Mirsky

Department of Agronomy and Horticulture: Faculty Publications

Winter cover crop performance metrics (i.e., vegetative biomass quantity and quality) affect ecosystem services provisions, but they vary widely due to differences in agronomic practices, soil properties, and climate. Cereal rye (Secale cereale) is the most common winter cover crop in the United States due to its winter hardiness, low seed cost, and high biomass production. We compiled data on cereal rye winter cover crop performance metrics, agronomic practices, and soil properties across the eastern half of the United States. The dataset includes a total of 5,695 cereal rye biomass observations across 208 site-years between 2001–2022 and encompasses …

Intensifying Rice Production To Reduce Imports And Land Conversion In Africa, Shen Yuan, Kazuki Saito, Pepijn A.J. Van Oort, Martin K. Van Ittersum, Shaobing Peng, Patricio Grassini

Department of Agronomy and Horticulture: Faculty Publications

Africa produces around 60% of the rice the continent consumes, relying heavily on rice imports to fulfill the rest of the domestic demand.Over the past 10 years, the rice-agricultural area increased nearly 40%, while average yield remained stagnant. Here we used a process-based crop simulation modelling approach combined with local weather, soil, and management datasets to evaluate the potential to increase rice production on existing cropland area in Africa and assess cropland expansion and rice imports by year 2050 for different scenarios of yield intensification. We find that Africa can avoid further increases in rice imports, and even reduce them, …

Filling The Agronomic Data Gap Through A Minimum Data Collection Approach, Fatima A. Tenorio, Juan I. Rattalino Edreira, Juan Pablo Monzon, Fernando Aramburu-Merlos, Achim Dobermann, Armelle Gruere, Juan Martin Brihet, Sofia Gayo, Shawn Conley, Spyridon Mourtzinis, Nester Mashingaidze, Alex Sananka, Stephen Aston, Jonathan J. Ojeda, Patricio Grassini

Department of Agronomy and Horticulture: Faculty Publications

Context: Agronomic data such as applied inputs, management practices, and crop yields are needed for assessing productivity, nutrient balances, resource use efficiency, as well as other aspects of environmental and economic performance of cropping systems. In many instances, however, these data are only available at a coarse level of aggregation or simply do not exist.

Objectives: Here we developed an approach that identifies sites for agronomic data collection for a given crop and country, seeking a balance between minimizing data collection efforts and proper representation of the main crop producing areas.

Methods: The developed approach followed a …

High Target Homology Does Not Guarantee Inhibition: Aminothiazoles Emerge As Inhibitors Of Plasmodium Falciparum, Sandra Johannsen, Robin M. Gierse, Arne KrüGer, Rachel L. Edwards, Vittoria Nanna, Anna Fontana, Di Zhu, Tiziana Masini, Lais Pessanha De Carvalho, Mael Poizat, Bart Kieftenbelt, Dana M. Hodge, Sophie University Of Nebraska-Lincoln,, Daan Bunt, Antoine Lacour, Atanaz Shams, Kamila Anna Meissner, Edmarcia Elisa De Souza, Melloney Dröge, Bernard Van Vliet, Jack Den Hartog, Michael C. Hutter, Jana Held, Audrey R. Odom John, Carsten Wrenger, Anna K.H. Hirsch

Department of Agronomy and Horticulture: Faculty Publications

In this study, we identified three novel compound classes with potent activity against Plasmodium falciparum, the most dangerous human malarial parasite. Resistance of this pathogen to known drugs is increasing, and compounds with different modes of action are urgently needed. One promising drug target is the enzyme 1-deoxy-D-xylulose-5- phosphate synthase (DXPS) of the methylerythritol 4-phosphate (MEP) pathway for which we have previously identified three active compound classes against Mycobacterium tuberculosis. The close structural similarities of the active sites of the DXPS enzymes of P. falciparum and M. tuberculosis prompted investigation of their antiparasitic action, all classes …

Soil Carbon And Nitrogen After Eight Years Of Rotational Grazing In The Nebraska Sandhills Meadows, Gandura O. Abagandura, Martha Mamo, W. H. Schacht, Aaron Shropshire, Jerry Volesky

Department of Agronomy and Horticulture: Faculty Publications

Grassland provides many ecosystem services; therefore, sustainable management practices of grassland are crucial for maintaining and enhancing its ecosystem health and resilience. Rotational grazing at a high stocking density (a.k.a., ultrahigh stocking density) is purported to sequester greater amounts of carbon (C) in grassland soils than rotational grazing at low stocking densities. This study was conducted in the Nebraska Sandhills meadows for eight years to evaluate how rotational grazing with different stocking densities can affect soil C and total nitrogen (TN) in bulk soils, soil organic matter fractions, and sequestration rate. The grazing management included a high stocking density with …

Genome-Wide Association And Genomic Prediction For Iron And Zinc Concentration And Iron Bioavailability In A Collection Of Yellow Dry Beans, Paulo Izquierdo, Rie Sadohara, Jason Wiesinger, Raymond Glahn, Carlos Urrea, Karen Cichy

Department of Agronomy and Horticulture: Faculty Publications

Dry bean is a nutrient-dense food targeted in biofortification programs to increase seed iron and zinc levels. The underlying assumption of breeding for higher mineral content is that enhanced iron and zinc levels will deliver health benefits to the consumers of these biofortified foods. This study characterized a diversity panel of 275 genotypes comprising the Yellow Bean Collection (YBC) for seed Fe and Zn concentration, Fe bioavailability (FeBio), and seed yield across 2 years in two field locations. The genetic architecture of each trait was elucidated via genome-wide association studies (GWAS) and the efficacy of genomic prediction (GP) was assessed. …

Proceedings Of The 51st Annual Meeting, Southern Soybean Disease Workers (March 6-7, 2024, Pensacola Beach, Florida), Ian Small, Kiersten A. Wise, Travis R. Faske, Danise Beadle, Paul Patrick Price Iii, Tom W. Allen

Southern Soybean Disease Workers: Conference Proceedings

Success in Extension (moderator: Kiersten Wise)

Institutional currency: What is important at your university? Loren Giesler

Success (and challenges) in extension in the Mid-West, Daren Mueller

Success in extension in the Mid-Atlantic, Alyssa Koehler

Success (and failures) in xxtension in the Southeast, Ed Sikora

Success in extension in the Mid-South, Travis Faske

Student Competition (moderator: Ian Small)

Hiding in plain sight: Disentangling the biology of Cercospora species associated with Cercospora leaf blight of soybean, Ernesto da Silva, J. Searight, J. Richards, P. Price, and V. Doyle

Using spore traps to decipher the epidemiology of Cercospora leaf blight in the mid-south, …

Adding Value To Crop Production Systems By Integrating Forage Cover Crop Grazing, Robert B. Mitchell, Daren D. Redfearn, Kenneth P. Vogel, Terry J. Klopfenstein, Galen Erickson, P. Steven Baenziger, Bruce E. Anderson, Mary E. Drewnoski, Jay Parsons, Steven D. Masterson, Marty R. Schmer, Virginia L. Jin

Department of Agronomy and Horticulture: Faculty Publications

In addition to their value as cereal grains, wheat (Triticum aestivum L.) and triticale (× Triticosecale Wittmack) are important cool-season annual forages and cover crops. Yearling steer (Bos taurus) performance was compared in the spring following autumn establishment as for age cover crops after soybean [Glycine max (L.) Merr.] grain harvest. Replicated pastures (0.4 ha) were no-till seeded in three consecutive years into soybean stubble in autumn, fertilized, and grazed the following spring near Ithaca, Nebraska, USA. Each pasture (n = 3) was continuously stocked in spring with four yearling steers (380 ± 38 kg) for …

Hop Cone Drying For The Small Grower: Temperature And Airflow Considerations, Stacy A. Adams, David M. Mabie, Michael F. Kocher, David Jones

Department of Agronomy and Horticulture: Faculty Publications

Small hop growers without nearby processors for cone stripping and drying must attempt to do so on their own farm. Challenges exist for self-built drying systems, including drying capacity, processing speed, airflow direction, and maintaining quality during drying. Research-based recommendations are given for optimal temperature, sizing of drying vessel, maximum cone depth, and influences associated with airflow on processing uniformity and cone quality are presented.

Early Season Biomass And Weather Enable Robust Cereal Rye Cover Crop Biomass Predictions, Alexandra M. Huddell, Brian Needleman, Eugene P. Law, Victoria J. Ackroyd, Muthukumar V. Bagavathiannan, Kevin Bradley, Adam S. Davis, Jeffrey A. Evans, Wesley Jay Everman, Michael Flessner, Nicholas Jordan, Lauren M. Schwartz-Lazaro, Ramon G. Leon, John L. Lindquist, Jason K. Norsworthy, Lovreet S. Shergill, Mark Vangessel, Steven B. Mirsky

Department of Agronomy and Horticulture: Faculty Publications

Farmers need accurate estimates of winter cover crop biomass to make informed decisions on termination timing or to estimate potential release of nitrogen from cover crop residues to subsequent cash crops. Utilizing data from an extensive experiment across 11 states from 2016 to 2020, this study explores the most reliable predictors for determining cereal rye cover crop biomass at the time of termination. Our findings demonstrate a strong relationship between early-season and late-season cover crop biomass. Employing a random forest model, we predicted late-season cereal rye biomass with a margin of error of approximately 1,000 kg ha⁻¹ based on …

Crop Dna Extraction With Lab-Made Magnetic Nanoparticles, Haichuan Wang, Xueqi Zhao, Li Tan, Junwei Zhu, David Hyten

Department of Agronomy and Horticulture: Faculty Publications

Molecular breeding methods, such as marker-assisted selection and genomic selection, require high-throughput and cost-effective methods for isolating genomic DNA from plants, specifically from crop tissue or seed with high polysaccharides, lipids, and proteins. A quick and inexpensive high-throughput method for isolating genomic DNA from seed and leaf tissue from multiple crops was tested with a DNA isolation method that combines CTAB extraction buffer and lab-made SA-coated magnetic nanoparticles. This method is capable of isolating quality genomic DNA from leaf tissue and seeds in less than 2 hours with fewer steps than a standard CTAB extraction method. The yield of the …

Microbiome-Enabled Genomic Selection Improves Prediction Accuracy For Nitrogen-Related Traits In Maize, Zhikai Yang, Tianjing Zhao, Hao Cheng, Jinliang Yang

Department of Agronomy and Horticulture: Faculty Publications

Root-associated microbiomes in the rhizosphere (rhizobiomes) are increasingly known to play an important role in nutrient acquisition, stress tolerance, and disease resistance of plants. However, it remains largely unclear to what extent these rhizobiomes contribute to trait variation for different genotypes and if their inclusion in the genomic selection protocol can enhance prediction accuracy. To address these questions, we developed a microbiome-enabled genomic selection method that incorporated host SNPs and amplicon sequence variants from plant rhizobiomes in a maize diversity panel under high and low nitrogen (N) field conditions. Our cross-validation results showed that the microbiome-enabled genomic selection model significantly …

Emerging Trends In Wheat (Triticum Spp.) Breeding: Implications For The Future, Mujahid Alam, P. Stephen Baenziger, Katherine Anna Frels

Department of Agronomy and Horticulture: Faculty Publications

Wheat (Triticum spp and, particularly, T. aestivum L.) is an essential cereal with increased human and animal nutritional demand. Therefore, there is a need to enhance wheat yield and genetic gain using modern breeding technologies alongside proven methods to achieve the necessary increases in productivity. These modern technologies will allow breeders to develop improved wheat cultivars more quickly and efficiently. This review aims to highlight the emerging technological trends used worldwide in wheat breeding, with a focus on enhancing wheat yield. The key technologies for introducing variation (hybridization among the species, synthetic wheat, and hybridization; genetically modified wheat; transgenic …

High Throughput Phenotyping: Field Based Triticale Breeding And Educational Resource Impact, Catherine Kay Mick

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

Triticale (Triticosecale) is a multifunctional hybrid cereal crop that adopted the hardiness of rye and wheat's high-yielding and nutritional qualities. Plant breeding programs work to improve the quality and number of varieties available to producers through multiple rounds of evaluation and selection. However, traditional phenotyping methods are labor-intensive, time-consuming, and destructive, creating a phenotyping bottleneck. Remote sensing using unmanned aerial systems has the potential to alleviate this issue and change the evaluation of phenotypes in a breeding. Demand for educational resources to advance public awareness and prepare the workforce has increased with the utilization of more technology in …

Vulnerabilities Of Greater Prairie Chicken And Tier 1 At-Risk Species In Nebraska Caused By Grassland Transition To Woody Dominance, Robert Peterson

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

Woody plant encroachment is a global threat and has been transitioning grasslands to woody dominance at a biome scale. This threat is present in the Great Plains grassland biome which is currently experiencing grassland biome collapse as the alternative woody biome advances northwest. Nebraska, which contains the most intact temperate grassland in the world, is currently at the front lines of this large-scale transition making this state’s management decisions vital for the remaining grasslands and the species which rely on these ecosystems. In this study, we assess the vulnerability of Greater Prairie Chicken and Tier 1 at-risk species in Nebraska …

Unraveling The Tapestry Of Indigenous Maize In North America: A Case Study Of Pawnee Ancestral Maize, Kahheetah Barnoskie

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

Studies on Indigenous ancestral landrace maize in North America has significant historical and scientific importance. Indigenous peoples, such as the Pawnee people, have been cultivating maize for thousands of years, resulting in diverse varieties adapted to their local environments. This study aims to deepen the knowledge of Indigenous maize by examining specific varieties from the Pawnee, including a comparative analysis of the genetic makeup through DNA sequencing. This study used Genotyping by Target Sequencing (GBTS) method to examine the genetic variation and characteristics among the multiple varieties the Pawnee people once grew historically, providing valuable information about the evolutionary history …

Assessing The Morphological And Physiological Traits Of Smooth Brome Pastures Under Long Term Grazing And Nutrient Enrichment In Eastern Nebraska, Hassan Shehab

School of Natural Resources: Dissertations, Theses, and Student Research

Climate change together with the increase in demands for food, feed, fuel, and fiber are becoming a threat to sustainability and resilience of agriculture and pasture lands. Bromus inermis (smooth bromegrass) dominates pastures for cattle grazing in Eastern Nebraska, US, where it is planted in monocultures, and is considered high quality forage because of its palatability and high nutritional value for cattle, especially under intensive management practices. Sustainable management of these pastures is key to long-term resilience. This study aims to assess the performance of smooth bromegrass pastures to the combined effects of long-term management practices (since 2005) of fertilization …

2020-2021 Field Seasons Of Maize Gxe Project Within The Genomes To Fields Initiative, Dayane Cristina Lima, Alejandro Castro Aviles, Ryan Timothy Alpers, Alden Perkins, Dylan L. Schoemaker, Martin Costa, Kathryn J. Michel, Shawn Kaeppler, David Ertl, Maria Cinta Romay, Joseph L. Gage, James Holland, Timothy Beissinger, Martin Bohn, Edward Buckler, Jode Edwards, Sherry Flint-Garcia, Michael A. Gore, Candice N. Hirsch, Joseph E. Knoll, John Mckay, Richard Minyo, Seth C. Murray, James Schnable, Rajandeep S. Sekhon, Maninder P. Singh, Erin E. Sparks, Peter Thomison, Addie Thompson, Mitchell Tuinstra, Jason Wallace, Jacob D. Washburn, Teclemariam Weldekidan, Wenwei Xu, Natalia De Leon

Department of Agronomy and Horticulture: Faculty Publications

Objectives: This release note describes the Maize GxE project datasets within the Genomes to Fields (G2F) Initiative. The Maize GxE project aims to understand genotype by environment (GxE) interactions and use the information collected to improve resource allocation efficiency and increase genotype predictability and stability, particularly in scenarios of variable environmental patterns. Hybrids and inbreds are evaluated across multiple environments and phenotypic, genotypic, environmental, and metadata information are made publicly available. Data description: The datasets include phenotypic data of the hybrids and inbreds evaluated in 30 locations across the US and one location in Germany in 2020 and 2021, soil …

A Global Faostat Reference Database Of Cropland Nutrient Budgets And Nutrient Use Efficiency (1961–2020): Nitrogen, Phosphorus And Potassium, Cameron I. Ludemann, Nathan Wanner, Pauline Chivenge, Achim Dobermann, Rasmus Einarsson, Patricio Grassini, Armelle Gruere, Kevin Jackson, Luis Lassaletta, Federico Maggi, Griffiths Obli-Laryea, Martin K. Van Ittersum, Srishti Vishwakarma, Xin Zhang, Francesco N. Tubiello

Department of Agronomy and Horticulture: Faculty Publications

Nutrient budgets help to identify the excess or insufficient use of fertilizers and other nutrient sources in agriculture. They allow for the calculation of indicators, such as the nutrient balance (surplus if positive or deficit if negative) and nutrient use efficiency, that help to monitor agricultural productivity and sustainability across the world. We present a global database of country-level budget estimates for nitrogen (N), phosphorus (P) and potassium (K) on cropland. The database, disseminated in FAOSTAT, is meant to provide a global reference, synthesizing and continuously updating the state of the art on this topic. The database covers 205 countries …

Do Organic Farming Practices Improve Soil Physical Properties?, Humberto Blanco-Canqui, Sabrina J. Ruis, Charles A. Francis

Department of Agronomy and Horticulture: Faculty Publications

Organic farming (OF) is a reemerging system that could address food security and adverse environmental footprints of conventional farming (CF). However, how OF affects the soil physical environment, an essential pillar for soil ecosystem service delivery, is not well understood. This paper (1) reviews published global literature up to 13 July 2023 regarding the impacts of OF on soil physical properties compared with CF and (2) underlines research needs. Literature indicates OF improves some soil physical properties relative to CF although studies on some properties were few. Specifically, OF increased wet aggregate stability, saturated hydraulic conductivity, and plant available water …

Root-Associated Bacterial Communities And Root Metabolite Composition Are Linked To Nitrogen Use Efficiency In Sorghum, Yen Ning Chai, Yunhui Qi, Emily Goren, Dawn Chiniquy, Amy M. Sheflin,, Susannah G. Tringe, Jessica E. Prenni, Peng Liu, Daniel P. Schachtman

Department of Agronomy and Horticulture: Faculty Publications

The development of cereal crops with high nitrogen use efficiency (NUE) is a priority for worldwide agriculture. In addition to conventional plant breeding and genetic engineering, the use of the plant microbiome offers another approach to improving crop NUE. To gain insight into the bacterial communities associated with sorghum lines that differ in NUE, a field experiment was designed comparing 24 diverse Sorghum bicolor lines under sufficient and deficient nitrogen (N). Amplicon sequencing and untargeted gas chromatography–mass spectrometry were used to characterize the bacterial communities and the root metabolome associated with sorghum genotypes varying in sensitivity to low N. We …

Does Selection For Seedling Tiller Number In Perennial Biomass Feedstocks Translate To Yield And Quality Improvements In Mature Swards?, Robert B. Mitchell, Kenneth P. Vogel, Susan Tunnell, James Stubbendieck

Department of Agronomy and Horticulture: Faculty Publications

Breeding for seedling traits in herbaceous perennial biomass feedstocks that translate into increased biomass yield or quality in established swards could accelerate the development of perennial grass cultivars for bioenergy or forage. In previously reported research, breeding for single large tillers (ST) or multiple tillers (MT, ≥3) six weeks after planting for two generations in big bluestem (Andropogon gerardii Vitman) and switchgrass (Panicum virgatum L.) base populations produced ST and MT populations that differed significantly for seedling and mature plant traits including biomass yield in spaced planted nurseries. Our objective was to evaluate these ST and MT populations in sward …

An Analysis Of Plant Response To Herbivory, Lawrence Gustavo Seminario-Romero

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Herbivory is often believed to always negatively affect the growth of plants, but there are plant species that can actually benefit from being consumed by herbivores. These plants have a phenotypic trait known as “compensatory growth.” A plant that exhibits compensatory growth is able to increase its intrinsic growth rate as a response to taking damage caused by herbivory, and as a result, produce more biomass. Very few mathematical models used to describe plant-herbivore interactions have accounted for plant compensatory growth. Moreover, these models tend to assume that herbivores follow a Holling type II functional response, which may not necessarily …

Genetic Analysis Of Basal Stalk Rot Resistance Introgressed From Wild Helianthus Petiolaris Into Cultivated Sunflower (Helianthus Annuus L.) Using An Advanced Backcross Population, Zahirul I. Talukder, William Underwood, Christopher G. Misar, Xuehui Li, Gerald J. Seiler, Xiwen Cai, Lili Qi

Department of Agronomy and Horticulture: Faculty Publications

Introduction: Sclerotinia sclerotiorum is a serious pathogen causing severe basal stalk rot (BSR) disease on cultivated sunflower (Helianthus annuus L.) that leads to significant yield losses due to insufficient resistance. The wild annual sunflower species H. petiolaris, commonly known as prairie sunflower is known for its resistance against this pathogen. Sunflower resistance to BSR is quantitative and determined by many genes with small effects on the resistance phenotype. The objective of this study was to identify loci governing BSR resistance derived from H. petiolaris using a quantitative trait loci (QTL) mapping approach.

Methods: BSR …

Effects Of Rootstock And Location On Open Field ‘Bhn 589’ And ‘Nebraska Wedding’ Grafted Tomato Yield, Raihanah H. Shonerd, Ashley A. Thompson, Samuel E. Wortman

Department of Agronomy and Horticulture: Faculty Publications

Grafted tomato (Solanum lycopersicum) production is popular, particularly in high tunnels, because grafted plants can mitigate soilborne disease incidence in highly infested soils and increase water and nutrient use efficiency and crop yield and quality. However, these potential benefits are not as well documented in open field production systems with less disease pressure. The objective of this study was to quantify the effect of tomato grafting on fruit yield, number, and size across 2 years (2018 and 2019) and three diverse open-field production environments in Nebraska (Lincoln, North Platte, and Dwight). At each location, a scion from one …

Evaluation Of Land Preparation Methods For Soil Stabilization, Revegetation, And Renewed Productivity In Semi-Arid Climates, Jarrett Lardy, North Dakota State University, Miranda Meehan, Aaron L. M. Daigh, James Staricka, Nathan Derby

Department of Agronomy and Horticulture: Faculty Publications

In the Williston Basin, land-preparation treatments have not been compared in side-by-side trials to evaluate performance for parameters such as runoff, erosion, and vegetation establishment. Thus, four treatments of wheat-straw crimping, land imprinting, wood-fiber hydromulch, and the combination of land imprinting and hydromulch were evaluated against a bare soil control in a replicated and randomized completed block field experiment near Williston, ND. Rainfall simulations were performed in September 2020 and June 2021 to examine the effectiveness of the treatments to reduce runoff and sediment losses. Vegetation establishment was also evaluated in August 2021. The wheat straw treatment reduced the equivalent …