Digital Commons Network^™

Using Annual Forages To Replace Declining Cool-Season Grass Pasture Availability, Jonathon Jenkins

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

As land area in grain crop production increases in the US Midwest, perennial pasture availability decreases but the demand increases. Matching the seasonal growth patterns of C₃ and C₄ plant species to grow forages that are complementary allows producers to fill production gaps in otherwise monoculture systems and possibly increase overall productivity. One way to fill the forage production gap of C₃ grass dominated pastures is by producing a warm-season, annual forage in a separate field. However, with continual reductions in land availability, this may not be an option. Using two studies, our objectives were to improve …

In-Field Optimization Of Soil Water Parameters For Irrigation Scheduling, Ishani Lal

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

Several precision technologies are being developed to assist farmers in informed irrigation decision-making. These technologies aim to enhance irrigation water efficiency, check overirrigation, boost crop water productivity, and promote the sustainable utilization of water resources. We hypothesize that soil moisture parameters used in irrigation decision tools need to be validated to best represent the correct state of soil moisture in the field. This is an important factor that affects the accuracy of the irrigation recommendations forecasted by the decision support tools. In this research, we evaluated different methods of estimating field capacity (FC) and wilting point (WP) to optimize soil …

Next-Generation Crop Monitoring Technologies: Case Studies About Edge Image Processing For Crop Monitoring And Soil Water Property Modeling Via Above-Ground Sensors, Nipuna Chamara

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

Artificial Intelligence (AI) has advanced rapidly in the past two decades. Internet of Things (IoT) technology has advanced rapidly during the last decade. Merging these two technologies has immense potential in several industries, including agriculture.

We have identified several research gaps in utilizing IoT technology in agriculture. One problem was the digital divide between rural, unconnected, or limited connected areas and urban areas for utilizing images for decision-making, which has advanced with the growth of AI. Another area for improvement was the farmers' demotivation to use in-situ soil moisture sensors for irrigation decision-making due to inherited installation difficulties. As Nebraska …

Establishment Of Wildflower Islands To Enhance Roadside Health, Ecological Value, And Aesthetics, Jackson Ebbers

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

Roadsides provide an abundant opportunity to increase connectivity of fragmented landscapes with diminishing floral resources for pollinating insects. The ecological value of these sites is often overlooked as quality habitat for pollinators, particularly monarch butterflies, which have been experiencing severe declines due to loss of habitat and loss of milkweeds that provide food for their larvae. Land managers across the nation are realizing the potential of roadsides to provide high quality floral resources for the benefit of insects and other wildlife. Current wildflower seed mixes used by state transportation departments are often low diversity and may only be implemented following …

Irt-Based Irrigation Scheduling And Dry Bean Crop Water Productivity Under Different Irrigation Scenarios In The Nebraska High Plains, Angie Gradiz

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Irrigation plays a critical role for crop production in western Nebraska of the United States, where crop evapotranspiration often exceeds in-season precipitation. This study investigated the impacts of different irrigation treatments on yield and key physiological parameters of dry edible beans grown in semi-arid western Nebraska during the 2022-2023 growing seasons. Seven irrigation levels (0%, 25%, 50%, 75%, 100%, 125%, 150%) of the fully irrigated treatment (FIT), were applied using a Variable Rate Irrigation (VRI) Linear-Move Sprinkler System. Additionally, an eighth treatment was scheduled based on measurement from infrared radiometry thermometers (IRT) to evaluate the performance of the two-source energy …

Public Horticulture: Process And Design Of The Lincoln Botanical Garden, Brad Kindler

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

Beginning in 2012, the local non-profit, The Lincoln Botanical Garden, began organizing the conceptual design and creation of a glass conservatory within a botanical garden in Lincoln, Nebraska. These proposed urban enhancements seek to fill a gap in garden amenities in the city by providing year-round access to public horticulture programming and education.

This project, Public Horticulture: Process and Design of the Lincoln Botanical Garden, documents these efforts and makes design recommendations for a themed Glacial Erratic Garden that could be constructed within the botanical garden.

Advisors: Ellen Paparozzi and Sam Wortman

Impact Of Plant Defenses And Aphid-Associated Microbes In Modulating Sorghum-Sugarcane Aphid Interactions, Edith Ikuze

Department of Entomology: Dissertations, Theses, and Student Research

Sorghum (Sorghum bicolor) is a vital cereal crop globally, facing challenges from invasive pests such as the sugarcane aphid (SCA; Melanaphis sacchari). To elucidate mechanisms of sorghum resistance to SCA, we examined the role of plant defenses and the influence of aphid-associated microbes in modulating sorghum defenses. Lignin is a complex heterogenous polymer present in nearly all plant cell walls that plays a critical role in protecting plants from various stresses. In this study, we investigated the role of the caffeoyl coenzyme-A O-methyltransferase (CCoAOMT), one of the core enzymes in monolignol biosynthesis pathway that leads to lignin …

Hilling As A Management Tactic And Tool For Understanding Soybean Gall Midge (Resseliella Maxima Gagné), Pragya Gupta

Department of Entomology: Dissertations, Theses, and Student Research

Soybean gall midge (Resseliella maxima Gagné, SGM) emerged as a new species in the United States Midwest in 2019, causing injury to soybean (Glycine max L.) Infestation of R. maxima starts with females laying eggs in the fissures or cracks that develop at the base of soybean during the V2-V3 growth stage. The emerged larvae feed on the stem internally, leading to wilting and death of the plants. With knowledge gaps in biology and behavior, management strategies for this pest are challenging. Hilling is a cultural practice causing soil to cover the base of stems and is …

Will Saf Turbocharge The Corn Ethanol Market?, Richard Perrin, Lilyan Fulginiti, Felipe Miranda De Souza Almeida

Cornhusker Economics

The long-run outlook for the corn ethanol industry is questionable, due to a transition to electric and hybrid vehicles. One source of hope for the long run is the potential demand for producing Sustainable Aviation Fuel (SAF). SAF is a key component in the United States Aviation Climate Action Plan, a path to net-zero greenhouse gas (GHG) emissions in the aviation industry by 2050. Demand for ethanol for SAF offers hope to the ethanol industry, but it depends a great deal on policy decisions that are being made now. Here we sketch out this story.

Based on the information available …

Field Research Report: Results From The Enreec Vri Field For The 2021, 2022, And 2023 Crop Seasons, Derek M. Heeren, Ali T. Mohammed, Eric Wilkening, Christopher M. U. Neale, Alan L. Boldt, Ankit Chandra, Precious Nneka Amori, Ivo Z. Goncalves, Yeyin Shi, Guillermo R. Balboa

Department of Biological Systems Engineering: Conference Presentations and White Papers

Long-term irrigation management research has been conducted from 2014 to 2023 for corn and soybean at the Eastern Nebraska Research, Extension, and Education Center (ENREEC) Variable Rate Irrigation (VRI) Field located in subhumid east-central Nebraska (in the Lower Platte North Natural Resources District). The objective of this report was to present the overall results from the VRI Field for 2021 to 2023. Across the three growing seasons, there were the following irrigation treatments: Best Management Practice (BMP), 50% BMP, 125% BMP, rainfed, Spatial ET Modeling Interface (SETMI), SDD1, SDD2, machine-learning-based Cyber-Physical System (CPS), a student team recommended rate, and industry …

Evaluation Of Ndot’S Sediment Barrier Practices Using Performance Data, Michael A. Perez, Wesley N. Donald, J. Blake Whitman, Brian G. Roche

Nebraska Department of Transportation: Research Reports

To protect waterways adjacent to construction projects with disturbed land, a 50 ft (15 m) vegetated buffer or equivalent sediment controls are required. However, there is little guidance on the effectiveness of vegetated buffers in removing sediment or how sediment barriers can aid shorter buffers or replace buffers. A modeling methodology was developed and used to determine the performance of 11,664 50 ft (15 m) vegetated buffer configurations with Nebraska conditions; sediment capture averaged 92.6% and ranged from 18.5% to 99.5%. To determine the performance of Nebraska Department of Transportation standard and modified sediment barrier installations, a large-scale testing methodology …

Pollinator Communities And Their Ecosystem Services At Conservation Grasslands And Adjacent Croplands, Araceli Gomez Villegas

Department of Entomology: Dissertations, Theses, and Student Research

Pollinators are intrinsically linked to the success of unmanaged and managed ecosystems by providing pollination services that aid in the reproduction of wildflowers and many crops. Land use change, habitat loss, fragmentation, and related landscape-level phenomena (for example, increased pesticide exposure) threaten pollinators and have been associated with population declines. In the Midwestern region of the United States, land conversion of native prairies and grasslands to row-crop agriculture has been one of the largest contributors to pollinator habitat loss. Conservation programs, such as the Conservation Reserve Program, have worked towards removing environmentally sensitive lands from agriculture production and enrolling them …

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 …

Perennializing Marginal Croplands: Going Back To The Future To Mitigate Climate Change With Resilient Biobased Feedstocks, Salvador Ramirez Ii, Marty R. Schmer, Virginia L. Jin, Robert B. Mitchell, Catherine E. Stewart, Jay Parsons, Daren D. Redfearn, John J. Quinn, Gary E. Varvel, Kenneth P. Vogel, Ronald F. Follett

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

Managing annual row crops on marginally productive croplands can be environmentally unsustainable and result in variable economic returns. Incorporating perennial bioenergy feedstocks into marginally productive cropland can engender ecosystem services and enhance climate resiliency while also diversifying farm incomes. We use one of the oldest bioenergy-specific field experiments in North America to evaluate economically and environmentally sustainable management practices for growing perennial grasses on marginal cropland. This long-term field trial called 9804 was established in 1998 in eastern Nebraska and compared the productivity and sustainability of corn (Zea mays L.)—both corn grain and corn stover—and switchgrass (Panicum virgatum …

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.

Life Cycle Greenhouse Gas Emissions In Maize No-Till Agroecosystems In Southern Brazil Based On A Long-Term Experiment, Guilherme Rosa Da Silva, Adam J. Liska, Cimelio Bayer

Biological Systems Engineering: Papers and Publications

Brazilian agriculture is constantly questioned concerning its environmental impacts, particularly greenhouse gas (GHG) emissions. This research study used data from a 34-year field experiment to estimate the life cycle GHG emissions intensity of maize production for grain in farming systems under no-tillage (NT) and conventional tillage (CT) combined with Gramineae (oat) and legume (vetch) cover crops in southern Brazil. We applied the Feedstock Carbon Intensity Calculator for modeling the “field-to-farm gate” emissions with measured annual soil N₂O and CH₄ emissions data. For net CO₂ emissions, increases in soil organic C (SOC) were applied as a proxy, …

Mycorrhizal Feedbacks Influence Global Forest Structure And Diversity, Camille S. Delavaux, Joseph A. Lamanna, Jonathan A. Myers, Richard P. Phillips, Salomón Aguilar, David Allen, Alfonso Alonso, Kristina J. Anderson-Teixeira, Matthew E. Baker, Jennifer L. Baltzer, Pulchérie Bissiengou, Mariana Bonfim, Norman A. Bourg, Warren Y. Brockelman, David F.R.P. Burslem, Li Wan Chang, Yang Chen, Jyh Min Chiang, Chengjin Chu, Keith Clay, Susan Cordell, Mary Cortese, Jan Den Ouden, Christopher Dick, Sisira Ediriweera, Erle C. Ellis, Anna Feistner, Amy L. Freestone, Thomas Giambelluca, Christian P. Giardina, Gregory S. Gilbert, Fangliang He, Jan Holík, Robert W. Howe, Walter Huaraca Huasca, Stephen P. Hubbell, Faith Inman, Patrick A. Jansen, Daniel J. Johnson, Kamil Kral, Sabrina E. Russo, Et Al.

Center for Plant Science Innovation: Faculty and Staff Publications

One mechanism proposed to explain high species diversity in tropical systems is strong negative conspecific density dependence (CDD), which reduces recruitment of juveniles in proximity to conspecific adult plants. Although evidence shows that plant-specific soil pathogens can drive negative CDD, trees also form key mutualisms with mycorrhizal fungi, which may counteract these effects. Across 43 large-scale forest plots worldwide, we tested whether ectomycorrhizal tree species exhibit weaker negative CDD than arbuscular mycorrhizal tree species. We further tested for conmycorrhizal density dependence (CMDD) to test for benefit from shared mutualists. We found that the strength of CDD varies systematically with mycorrhizal …

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 …

Human Dimensions Of Woody Encroachment Management In Nebraska, Emily Rowen

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

Woody plant encroachment (WPE) is a social-ecological problem that will challenge conservation professionals and agricultural producers to adapt their management strategies. This research first examined WPE from the perspective of individual conservation professionals through an online survey. Conservation professionals’ attitudes about adaptation to vegetation transitions, such as WPE, were of interest because these attitudes are one measure of how prepared this group is to respond to WPE. Hypothesized predictors of adaptation attitude were tested through linear regression modeling. These predictors included ecological change, observation of WPE, or risk perception. It was found that risk perception was the strongest predictor of …

A Global-Temporal Analysis On Phytophthora Sojae Resistance-Gene Efficacy, Austin G. Mccoy, Richard R. Belanger, Carl A. Bradley, Daniel G. Cerritos-Garcia, Vinicius C. Garnica, Loren Giesler, Pablo E. Grijalba, Eduardo Guillin, Maria A. Henriquez, Yong Min Kim, Dean K. Malvick, Rashelle L. Matthiesen, Santiago X. Mideros, Zachary A. Noel, Alison E. Robertson, Mitchell G. Roth, Clarice L. Schmidt, Damon L. Smith, Adam H. Sparks, Darcy E.P. Telenko, Vanessa Tremblay, Owen Wally, Martin I. Chilvers

Department of Plant Pathology: Faculty Publications

Plant disease resistance genes are widely used in agriculture to reduce disease outbreaks and epidemics and ensure global food security. In soybean, Rps (Resistance to Phytophthora sojae) genes are used to manage Phytophthora sojae, a major oomycete pathogen that causes Phytophthora stem and root rot (PRR) worldwide. This study aims to identify temporal changes in P. sojae pathotype complexity, diversity, and Rps gene efficacy. Pathotype data was collected from 5121 isolates of P. sojae, derived from 29 surveys conducted between 1990 and 2019 across the United States, Argentina, Canada, and China. This systematic review shows a loss of efficacy of …

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 …

Responses Of Maize To Different Irrigation Regimes In Semi-Arid Western Nebraska, Swathi Palle

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

As the “Cornhusker State”, Maize (Zea mays) is an important crop in Nebraska. However, farmers in the state are challenged by unstable supply of surface water and limited groundwater resources. A better understanding of maize's response to water stress that occurs at different growth stages can help implement the best irrigation practices that conserve water while maintaining yields. In this study, we conducted field experiments at the Panhandle Research, Extension, and Education Center to compare the responses of maize to eight irrigation treatments which included both limited and deficit irrigation regimes during 2022 and 2023 growing seasons. Specifically, …

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 …

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 …

Evaluation Of Vegetative Indices To Determine Canopy Ground Cover For Winter Survival And Hybrid Necrosis In Winter Wheat, Micheal Young

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

The benefit of unmanned aircraft systems and image processing methods in agronomic research across numerous crops has been well documented as has the importance of wheat, Triticum aestivum L., on the global food supply. Hence there is great interest in digital solutions applied to aspects of wheat breeding. A major trait of importance to winter wheat breeders in higher latitudes is winter survival, which can result in poor yield and performance if lines do not survive extreme cold. Scoring winter survival is most commonly based on visual score of 0% to 100% with the higher percentage conveying higher winter survival …

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 …

Game-Theoretic Approaches To Optimal Resource Allocation And Defense Strategies In Herbaceous Plants, Molly R. Creagar

Department of Mathematics: Dissertations, Theses, and Student Research

Empirical evidence suggests that the attractiveness of a plant to herbivores can be affected by the investment in defense by neighboring plants, as well as investment in defense by the focal plant. Thus, allocation to defense may not only be influenced by the frequency and intensity of herbivory but also by defense strategies employed by other plants in the environment. We incorporate a neighborhood defense effect by applying spatial evolutionary game theory to optimal resource allocation in plants where cooperators are plants investing in defense and defectors are plants that do not. We use a stochastic dynamic programming model, along …

Potential Hybridization Among Two Species Of California Salvia, Ellie Morrison, Bryan Drew

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

Hybridization among plants is fairly common, particularly in instances where closely related species are sympatric. One example of a group in which hybridization has been detected is the genus Salvia (Lamiaceae; mint family). Salvia is a diverse genus consisting of about 1,000 species and is defined primarily by having only two stamens, each with their anther sacs separated by elongated connective tissue. The genus has diversity centers around the world, including Southwest Asia and the Mediterranean region, Mexico/Central America, northern and central South America, and temperate East Asia. The genus also has a smaller species radiation of 19 species in …

The Pseudomonas Syringae Pv. Tomato Dc3000 Effector Hopd1 Interferes With Cellular Dynamics Associated With The Function Of The Plant Immune Protein Atnhr2b, Luis Francisco Marín-Ponce, Catalina Rodríguez-Puerto, Perla Rocha-Loyola, Clemencia M. Rojas

Department of Plant Pathology: Faculty Publications

The plant pathogenic bacterium Pseudomonas syringae pv. tomato DC3000 (Pst DC3000) causes disease in tomato, in the model plant Arabidopsis thaliana, and conditionally in Nicotiana benthamiana. The pathogenicity of Pst DC3000 is mostly due to bacterial virulence proteins, known as effectors, that are translocated into the plant cytoplasm through the type III secretion system (T3SS). Bacterial type III secreted effectors (T3SEs) target plants physiological processes and suppress defense responses to enable and support bacterial proliferation. The Pst DC3000 T3SE HopD1 interferes with plant defense responses by targeting the transcription factor NTL9. This work shows that HopD1 also targets …

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 …