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Influence Of Cover Crop Management Practices On Rainfed Corn Production In Semi-Arid Western Nebraska, Alexandre Tonon Rosa Jul 2020

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

Theses, Dissertations, and Student Research in Agronomy and Horticulture

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 ...


Effects Of Char On Nitrogen Management In Agricultural Soils Of Semi-Arid Western Nebraska, Dinesh Panday Jul 2020

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

Theses, Dissertations, and Student Research in Agronomy and Horticulture

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 ...


Effects Of Tank Contamination And Impact Of Drift-Reducing Agents On Weed Control In Response To Dicamba Applications, Milos Zaric Jul 2020

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

Theses, Dissertations, and Student Research in Agronomy and Horticulture

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 ...


Evaluating Opportunities For Integrated Crop Livestock Systems In Eastern Nebraska, Elizabeth Kay Christenson Jul 2020

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

Theses, Dissertations, and Student Research in Agronomy and Horticulture

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 2016, only ...


Weed Control Efficacy Of Bio-Based Sprayable Mulch Films In Specialty Crop Systems, Eliott Gloeb Jun 2020

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

Theses, Dissertations, and Student Research in Agronomy and Horticulture

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 ...


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 M. Striegel May 2020

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 M. Striegel

Theses, Dissertations, and Student Research in Agronomy and Horticulture

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 ...


Buffalograss Diversity Assessment, Collin Marshall Apr 2020

Buffalograss Diversity Assessment, Collin Marshall

Theses, Dissertations, and Student Research in Agronomy and Horticulture

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 cultivars ...


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 Apr 2020

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

Theses, Dissertations, and Student Research in Agronomy and Horticulture

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 eight races of the bean rust pathogen ...


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 Apr 2020

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

Theses, Dissertations, and Student Research in Agronomy and Horticulture

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.


Spring Meadow Management Practices: What’S A Rancher To Do?, Tara M. Harms, Jerry D. Volesky, Mitchell B. Stephenson Apr 2020

Spring Meadow Management Practices: What’S A Rancher To Do?, Tara M. Harms, Jerry D. Volesky, Mitchell B. Stephenson

Theses, Dissertations, and Student Research in Agronomy and Horticulture

• Subirrigated meadows are a valuable forage resource to ranching operations in the Nebraska Sandhills, being used for both hay production and livestock grazing. • The water table of these meadows is within one meter of the soil surface during the growing season. • In some years, wet conditions hinder meadow utilization, resulting in a buildup of standing dead and litter plant material which can lower forage production.

• Investigate if burning and mowing are effective strategies to remove dead plant material from meadows • Determine if burning or mowing interact with grazing to influence end of season forage production

Burning or mowing effectively removes ...


Herbicide Injury From Dicamba And 2,4-D: How Much Is Too Much In Lettuce?, Xinzheng Chen, Amit J. Jhala, Stevan Z. Knezevic, Samuel E. Wortman Apr 2020

Herbicide Injury From Dicamba And 2,4-D: How Much Is Too Much In Lettuce?, Xinzheng Chen, Amit J. Jhala, Stevan Z. Knezevic, Samuel E. Wortman

Theses, Dissertations, and Student Research in Agronomy and Horticulture

Off-target herbicide injury from dicamba and 2,4-D is an increasingly common problem for specialty crop growers in the Midwest U.S. Lettuce (Lactuca sativa L.) is a common specialty crops grown in Nebraska, but proximity to corn and soybean production leaves growers vulnerable to crop injury and significant economic loss. The goal of this study was to quantify crop injury and yield loss in greenhouse grown lettuce after exposure to simulated sub-lethal drift rates of 2,4-D and dicamba. Sublethal doses were determined based on a percentage of the maximum labeled rate and ranged from 25% to 0.01 ...


Soybean Response To Water: Trait Identification And Prediction, Shawn Jenkins Feb 2020

Soybean Response To Water: Trait Identification And Prediction, Shawn Jenkins

Theses, Dissertations, and Student Research in Agronomy and Horticulture

The rising demand for soybean [Glycine Max (L.) Merrill] taken in consideration with current climatic trends accentuates the importance of improving soybean seed yield response per unit water (WP). To further our understanding of the quantitative WP trait, a multi-omic approach was implemented for improved trait identification and predictive modeling opportunities. Through the evaluation of two recombinant inbred line populations jointly totaling 439 lines subjected to contrasting irrigation treatments, informative agronomic, phenomic, and genomic associations were identified. Across both populations, relationships were identified between lodging at maturity (r = -0.58, H = 0.86), canopy to air temperature differential at the ...


Evaluating The Impact Of Grafting On Local Tomato Production In Nebraska, Raihanah Hassim, Samuel E. Wortman, Ashley A. Thompson, Stacy A. Adams Jan 2020

Evaluating The Impact Of Grafting On Local Tomato Production In Nebraska, Raihanah Hassim, Samuel E. Wortman, Ashley A. Thompson, Stacy A. Adams

Theses, Dissertations, and Student Research in Agronomy and Horticulture

Grafting has been successfully used in vegetable production for tomatoes, peppers, eggplants, cucumbers, and watermelon. Besides its usefulness for managing soil-borne diseases, grafting can improve nutrient uptake and yield. However, few studies have assessed the effects of grafting and soil fertility management on yield of open field-grown tomatoes in the Midwest. Therefore, the objective of this two-year research was to better document the effects of grafting heirloom and hybrid tomato cultivar onto hybrid tomato rootstocks on tomato yield and quality. The field experiments were located at the University of Nebraska Lincoln - East Campus in Lincoln, West Central Research and Extension ...


Critical Time For Weed Removal In Corn (Zea Mays L.) As Influenced By Pre Herbicides, Ayse Nur Ulusoy Dec 2019

Critical Time For Weed Removal In Corn (Zea Mays L.) As Influenced By Pre Herbicides, Ayse Nur Ulusoy

Theses, Dissertations, and Student Research in Agronomy and Horticulture

A weed control program that utilizes PRE herbicides and ensures a timely post-emergence weed removal could protect growth and yield of corn. The use of pre-emergence (PRE) herbicides for weed control could reduce the need for multiple POST applications of glyphosate in glyphosate-tolerant (GT) corn and provide an additional mode of action for combating glyphosate-resistant weeds. Thus, field studies were conducted in 2017 and 2018 at Concord, NE with the following objectives develop weed management recommendations that considers soil applied herbicides and determine proper timing of glyphosate based on the crop growth stage.

Therefore the material in this thesis is ...


Use Of Uav Imagery And Nutrient Analyses For Estimation Of The Spatial And Temporal Contributions Of Cattle Dung To Nutrient Cycling In Grazed Ecosystems, Amanda Shine Dec 2019

Use Of Uav Imagery And Nutrient Analyses For Estimation Of The Spatial And Temporal Contributions Of Cattle Dung To Nutrient Cycling In Grazed Ecosystems, Amanda Shine

Theses, Dissertations, and Student Research in Agronomy and Horticulture

Nutrient inputs from cattle dung are crucial drivers of nutrient cycling processes in grazed ecosystems. These inputs are important both spatially and temporally and are affected by variables such as grazing strategy, water location, and the nutritional profile of forage being grazed. Past research has attempted to map dung deposition patterns in order to more accurately estimate nutrient input, but the large spatial extent of a typical pasture and the tedious nature of identifying and mapping individual dung pats has prohibited the development of a time- and cost-effective methodology. The first objective of this research was to develop and validate ...


Understanding Nitrogen Limitation In Soybean, Nicolas Cafaro La Menza Dec 2019

Understanding Nitrogen Limitation In Soybean, Nicolas Cafaro La Menza

Theses, Dissertations, and Student Research in Agronomy and Horticulture

Meeting soybean demand on existing cropland area for a global population of 9.7 billion people by the year 2050 requires narrowing the existing gap between average producer yield and yield potential. Soybean relies on two sources on nitrogen (N): biological N2 fixation and indigenous soil N supply. As soybean yield continues to increase, it seems critical to know if there is a yield level at which potential contribution of indigenous nitrogen sources and fixation becomes insufficient to meet crop N requirements for high yields, while still maintaining or increasing protein and oil concentration. This study evaluated N limitation across ...


Effects Of Different Water And Nitrogen Regimens On Yield Of Winter Wheat Produced In Nebraska, Joseph Emory Davis Dec 2019

Effects Of Different Water And Nitrogen Regimens On Yield Of Winter Wheat Produced In Nebraska, Joseph Emory Davis

Theses, Dissertations, and Student Research in Agronomy and Horticulture

Wheat is the 3rd most prominent crop in the USA and approximately 50% is exported annually. Nebraska wheat production is 11th in the country, and it plays a major role in the state's agricultural economy, especially in western NE. Generally, wheat is grown under dryland conditions and the region grows much more wheat on unirrigated land than it does on irrigated. However, deficit irrigation has shown great value in producing high yielding wheat with much less water than needed for other crops. Finding new ways to leverage irrigation in wheat production may help address the need to produce ...


Integration Of Cover Crops Into Midwest Corn-Soybean Cropping Systems And Potential For Weed Suppression, Joshua S. Wehrbein Dec 2019

Integration Of Cover Crops Into Midwest Corn-Soybean Cropping Systems And Potential For Weed Suppression, Joshua S. Wehrbein

Theses, Dissertations, and Student Research in Agronomy and Horticulture

Cover crops have potential to provide benefits to agricultural systems, such as improved soil productivity, nutrient scavenging, weed suppression, and livestock forage. There are several challenges associated with cover crop integration into traditional Midwest corn-soybean cropping systems. One of these challenges is timely establishment in the fall, which is limited by the relatively late harvest of corn and soybean. Cover crop effectiveness is related to the amount of biomass produced, thus maximizing the growth period in the fall is desired. To address this challenge, we evaluated the potential to utilize early-season soybean maturity groups (MGs) to allow for earlier soybean ...


A Survey Of Soil Properties Affecting Vegetation Establishment Along Nebraska Highways, Shad D. Mills Dec 2019

A Survey Of Soil Properties Affecting Vegetation Establishment Along Nebraska Highways, Shad D. Mills

Theses, Dissertations, and Student Research in Agronomy and Horticulture

Vegetation along roadsides is important to prevent soil erosion, provide habitat and filter water running off the road. Along some highways in Nebraska vegetation does not readily establish and persist. It is thought that sodium and bulk density issues are the driving factor behind the lack of vegetation. After a construction project, the shoulder is seeded into the compacted soil, and salts can accumulate in the soil due to deicing agents being used during the winter. The purpose of our study was to determine if the bulk density and sodium are the driving factors of the vegetation cover. We also ...


Legacy Effects Of Biodegradable Mulch And Soil Amendments On Vegetable Crops And The Soil, Elise V.H. Reid Nov 2019

Legacy Effects Of Biodegradable Mulch And Soil Amendments On Vegetable Crops And The Soil, Elise V.H. Reid

Theses, Dissertations, and Student Research in Agronomy and Horticulture

Plastic film mulches are used in horticulture to manage weeds, improve water retention, and increase soil temperature. Bioplastics and biofabrics are potentially sustainable alternatives to plastic film; however, they have different rates of in soil degradation. Polylactic acid (PLA) is a 100% biobased polymer that degrades slowly, but could fulfill organic certification to be soil incorporated. Mater-Bi is a commercially available biodegradable plastic (bioplastic), which degrades quickly, but cannot be incorporated in organic systems. Our objectives were to determine the individual and combined effects of soil amendments and residual mulch on vegetable crop yield and soil fertility. In a two-year ...


Canavalia And Dolichos Extracts For Sustainable Pest Biocontrol And Plant Nutrition Improvement In El Salvador, Carlos Martinez Oct 2019

Canavalia And Dolichos Extracts For Sustainable Pest Biocontrol And Plant Nutrition Improvement In El Salvador, Carlos Martinez

Theses, Dissertations, and Student Research in Agronomy and Horticulture

Botanical repellents and pesticides are now being rediscovered as new tools for integrated pest management in order to reduce the use of toxic chemicals in crop production. Canavalia gladiata and Dolichos lablab are two Fabaceae very well adapted to farmlands of El Salvador, effective as living barriers and mostly as cover crops, however, they are not yet very well disseminated. This document describes the potential for using the liquid extracts and the dry flour of raw seeds of those plants for economic benefit and practical convenience for pest management in Salvadorian agriculture under field conditions. Seed extracts were useful when ...


Challenges And Opportunities For Weed Control In Nebraska Popcorn, Ethann R. Barnes Oct 2019

Challenges And Opportunities For Weed Control In Nebraska Popcorn, Ethann R. Barnes

Theses, Dissertations, and Student Research in Agronomy and Horticulture

Weed control in popcorn is challenging with limited herbicide options and popcorn’s perceived sensitivity to herbicides. Understanding the impact of weeds maximizes yield and profit. New herbicide-resistant crops increase chances of drift or misapplication into popcorn, which doesn’t have herbicide-resistant traits. Herbicides that are labeled in popcorn are often only conditionally labeled with reduce rates, warnings, or limited popcorn types. Dent-sterility in popcorn is contingent on the Ga1 gene (Ga1-s), but this system is at risk from Ga1-m field corn introduced from Mexico because it overcomes dent-sterility. This risk is under-assessed as Ga1-m carriers are undocumented and Mexican ...


Expression Of Multi-Domain Lytic Peptide Genes In Transgenic Plants For Disease Resistance, George Biliarski Aug 2019

Expression Of Multi-Domain Lytic Peptide Genes In Transgenic Plants For Disease Resistance, George Biliarski

Theses, Dissertations, and Student Research in Agronomy and Horticulture

Four non-plant multi-domain lytic peptide genes coding for antimicrobial peptides were expressed in Nicotiana benthamiana plants and tested against three fungal pathogens: Sclerotinia sclerotiorum, Rhizoctonia solani, and Pythium sp. Detached-leaf bioassay was performed for the transgenic plants carrying multi-domain lytic peptide constructs and compared with transgenic and wild type control plants. Symptom area of each leaf was measured with high precision using the Compu-Eye software and processed by SAS statistical package. The transgenic lines ORF13 and RSL1 showed substantial resistance to Sclerotinia sclerotiorum infection producing significantly smaller lesion areas compared to control plants. However, these lines were not ...


An Integrated Genomics And Phenomics Approach To Study The Evolution Of C4 Photosynthesis, Daniel Santana De Carvalho Aug 2019

An Integrated Genomics And Phenomics Approach To Study The Evolution Of C4 Photosynthesis, Daniel Santana De Carvalho

Theses, Dissertations, and Student Research in Agronomy and Horticulture

The C4 photosynthetic pathway was first described over 50 years ago. Today, it is known that C4 evolved independently > 60 in plant lineages, which involves understanding not only the genetic, but also the metabolic features and differences involved in this process. Also, several adaptations are involved in the evolution of this type of photosynthesis, for example: changes in leaf anatomy and the evolution of kranz anatomy, physiology and metabolic pathways. In order to further investigate this pathway, different technologies and methods have been developed to unravel genes involved in C4 photosynthesis. With the advances in molecular biology and bioinformatics tools ...


Rust And Viral Mosaic Diseases In Biofuel Switchgrass, Anthony A. Muhle Aug 2019

Rust And Viral Mosaic Diseases In Biofuel Switchgrass, Anthony A. Muhle

Theses, Dissertations, and Student Research in Agronomy and Horticulture

Switchgrass (Panicum virgatum L.) is a perennial warm-season monocot that is indigenous to locations in North America east of the Rocky Mountains, and is considered a model grass for biofuel feedstock production. As switchgrass production increases, diseases pose a potential threat to biomass production and ethanol extraction. The two predominant switchgrass diseases in Nebraska are rust caused by Puccinia spp. and a viral mosaic disease caused by Panicum mosaic virus (PMV) and its associated Satellite panicum mosaic virus (SPMV). In this thesis, one study determined how SPMV affects PMV infection and systemic spread in two populations of switchgrass at different ...


Investigating Parental Effects On End-Use Quality In Hard Winter Wheat (Triticum Aestivum L.) Hybrids, Anthony Delaney Aug 2019

Investigating Parental Effects On End-Use Quality In Hard Winter Wheat (Triticum Aestivum L.) Hybrids, Anthony Delaney

Theses, Dissertations, and Student Research in Agronomy and Horticulture

To optimize the performance and marketing of hybrid wheat, breeders need to understand the impact parents have on end-use quality. The goal of this study was to investigate the inheritance of end-use quality traits of hard winter wheat reciprocal hybrids produced by Easterly (2017). The 2016 analysis included 71 reciprocal hybrid combinations from 13 parents and the 2017 analysis included 79 reciprocal hybrid combinations from 14 parents. The reciprocals were composed of crosses between the top performing and bottom performing parents with respect to end-use quality as quantified by a Mixograph, a SDS sedimentation assay, and a SDS-SRC hybrid assay ...


Hormonal Signaling Induced In Soybean By Lysobacter Enzymogenes Strain C3, Jessica C. Walnut Aug 2019

Hormonal Signaling Induced In Soybean By Lysobacter Enzymogenes Strain C3, Jessica C. Walnut

Theses, Dissertations, and Student Research in Agronomy and Horticulture

The biological control bacterium Lysobacter enzymogenes strain C3 has been shown to suppress fungal diseases by producing a suite of lytic enzymes and antimicrobial secondary metabolites. Previous studies have found that C3, when applied to grass and cereal plants, also is capable of inducing local and systemic resistance against fungal pathogens. It is unknown, however, whether the bacterium has the ability to induce resistance in dicots and what signaling pathways are involved. This study assessed the ability of C3 to trigger local and systemic induced resistance responses in soybean (Glycine max ‘Williams82’) by analyzing relative expression of salicylic acid (SA ...


New Approaches To Use Genomics, Field Traits, And High-Throughput Phenotyping For Gene Discovery In Maize (Zea Mays), Zhikai Liang Aug 2019

New Approaches To Use Genomics, Field Traits, And High-Throughput Phenotyping For Gene Discovery In Maize (Zea Mays), Zhikai Liang

Theses, Dissertations, and Student Research in Agronomy and Horticulture

Maize is one of major crop species over the world. With lots of genetic resources and genomic tools, maize also serves as a model species to understand genetic diversity, facilitate the development of trait extraction algorithms and map candidate functional genes. Since the first version of widely used B73 reference genome was released, independent research groups in the maize community propagated seeds themselves for further research purposes. However, unexpected or occasional contamination may happen during this process. The first study in this thesis used public RNA-seq data of B73 from 27 research groups across three countries for calling single nucleotide ...


Microbial Response To Biodegradable Mulch: Can Degradation Rate Be Accelerated By Management?, M. Benjamin Samuelson Aug 2019

Microbial Response To Biodegradable Mulch: Can Degradation Rate Be Accelerated By Management?, M. Benjamin Samuelson

Theses, Dissertations, and Student Research in Agronomy and Horticulture

Single-use, petroleum-based polyethylene mulch is ubiquitous in certified organic mulched vegetable systems, representing a broken nutrient cycle and a waste concern. Current organic-allowable biodegradable mulches cannot match the performance of polyethylene, in part because of the requirements that they contain 100% bio-based feedstock, and biodegrade within two years after soil incorporation. It is valuable to understand whether management can influence postharvest degradation rate of mulch films. Two biodegradable mulches: a potentially organic nonwoven polylactic acid and wood particle prototype (PLA), and a widely-adopted non-organic starch/copolymer blend, Bio360® (BLK), were used in field trials in two distinct ecoregions of Nebraska ...


Introduction To Sorghum Paper Production, Zachary Christman May 2019

Introduction To Sorghum Paper Production, Zachary Christman

Theses, Dissertations, and Student Research in Agronomy and Horticulture

Sorghum is a tall grass used for many commercial products such as fodder and syrup. The 10 to 15 feet stalk of the plant has lower lignin than wood and provides a fiber length of 2.31 mm in the outer covering and 1.38 mm for the leaf. Sorghum fiber makes a high quality, strong paper suitable for printing, packaging and paperboard.