Agronomy and Crop Sciences Commons^™

Measuring Impacts Of Uncertainty, Irreversibility, And Loss Aversion On The Adoption Of Crop Canopy Sensors Among Nebraska Corn Producers, Brooks Ronspies

Department of Agricultural Economics: Dissertations, Theses, and Student Research

Understanding barriers to adoption of Precision Agricultural Technologies (PATs) is important to the growth of agricultural productivity, efficiency, and sustainability. This thesis proposes and evaluates a model for estimating the impact of uncertainty, irreversibility, and loss aversion on producers’ adoption of crop canopy sensors in order to explain adoption behavior that contradicts previous expectations about the conditions necessary for technology adoption. The model is evaluated using estimated statistical distributions of price and field characteristics designed to match observations of actual corn and nitrogen prices, and of conventional and crop canopy sensor based nitrogen application. Results from this model using expected …

Management Considerations For Palmer Amaranth In A Northern Great Plains Soybean Production System, Brian Vab De Stroet, Sharon Clay

Agronomy, Horticulture and Plant Science Faculty Publications

Palmer amaranth (Amaranthus palmeri S. Watson) was first observed in a South Dakota field in 2015. This study assessed Palmer amaranth growth based on planting date (PD), impact on soybean [Glycine max (L.) Merr.] yield, and response of seedlings of South Dakota biotype seedlings to herbicides with different mechanisms of action (MOA). Soybean yield loss was influenced by Palmer amaranth density in 2016 (p = 0.001), with yield losses of 33% at densities greater than 15 plants m⁻² (R² = 0.65), although yield losses at low densities were greater than predicted by the fitted …

Predicting Economic Optimal Nitrogen Rate With The Anaerobic Potentially Mineralizable Nitrogen Test, Jason D. Clark, Fabian G. Fernandez, Kristen S. Veum, James J. Camberato, Paul R. Carter, Richard B. Ferguson, David W. Franzen, Daniel E. Kaiser, Newell R. Kitchen, Carrie A.M. Laboski, Emerson D. Nafziger, Carl J. Rosen, John E. Sawyer, John F. Shanahan

Agronomy, Horticulture and Plant Science Faculty Publications

Estimates of mineralizable N with the anaerobic potentially mineralizable N (PMN_an) test could improve predictions of corn (Zea mays L.) economic optimal N rate (EONR). A study across eight US midwestern states was conducted to quantify the predictability of EONR for single and split N applications by PMN_an. Treatment factors included different soil sample timings (pre-plant and V5 development stage), planting N rates (0 and 180 kg N ha⁻¹), and incubation lengths (7, 14, and 28 d) with and without initial soil NH₄–N included with PMN_an. Soil was sampled …

Studies On Pathogenesis Of The Diseases Caused By Macrophomina Phaseolina And Phomopsis Longicolla On Soybean, Marcio Leizer Zaccaron

Graduate Theses and Dissertations

Soybean (Glycine max), a legume, is an economically important crop in many parts of the world, including the USA, Brazil, Argentina, China, and India, currently the top five producing countries. Soybean is primarily used as feed, with incising markets for food and biodiesel. Similar to most crops, soybean yield and quality are affected by a diverse group of plant pathogens. In particular, several species of filamentous fungi have been the cause of severe yield losses in most growing regions world-wide. The soil born fungus Macrophomina phaseolina, causal agent of charcoal rot, has been found to be endemic to several soybean …

Selectivity Of Infrared Heat Treatment On Inactivation Of Mycotoxigenic Fungi On Stored Grain, Shantae A. Wilson

Graduate Theses and Dissertations

Selective Infrared (IR) heating holds great potential to decontaminate spores of unsafe fungi in corn. The objectives for this study were to investigate the impact of exposing corn to infrared energy at selected peak wavelengths (λ), infrared intensities and treatment durations, followed by tempering for further inactivation of microbes on the grain and explore a method for decontaminating Aspergillus flavus (A. flavus) spores on corn. Freshly harvested corn with initial moisture contents (IMCs) of 16%, 20%, and 24% wet basis (w.b.) were used. The corn samples were treated at different infrared wavelengths (3.2, 4.5, and 5.8 μm) for 20, 40 …

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

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

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 …

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

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

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 …

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

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

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, at …

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

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

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. …

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

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

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 …

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

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

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 …

Dual Biological Control: Characterization Of Fungi And Bacteria To Control Granary Weevil And Fungal Pathogens Of Stored Grain, Gülçin Ercan

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

Cereals are main food sources for humans and animals. However, during storage, cereal grains can be infested by insects and fungi. One of the most important insect storage pests is Sitophilus granarius (L., Coleoptera: Curculionidae). Adults and larvae can cause serious grain losses. In addition to insect pests, fungal pathogens may also invade the grain and cause economic loss, including contamination with mycotoxins, which threaten mammal health by causing serious disease. The most common mycotoxigenic grain fungi are species that belong to the genera Fusarium, Aspergillus and Penicillium. Currently, the most commonly used management strategies for insect and …

B.R. Wells Arkansas Rice Research Studies 2018, R. J. Norman, K. A.K. Moldenhauer

Arkansas Agricultural Experiment Station Research Series

No abstract provided.

Impacts Of Size Fractionation And Processing On Functional Characteristics Of Broken Rice Kernels, Rebecca Mawusi Bruce

Graduate Theses and Dissertations

Rice flour generated from broken rice (brokens) has inconsistencies in functional properties. This may be due to differences in size and composition of brokens used for the flour. It is postulated that size classification of brokens can improve flour functionality. This study sought to investigate the effect of size fractionation of brokens on the functional or pasting properties of resulting rice flour. Broken rice was generated from six cultivars of freshly harvested rough rice that were dried at 25◦C in the laboratory. The brokens were classified into large, medium and small, using US sieve size 10, 12 and 20 respectively. …

Effects Of Germination Conditions Of Brown Rice In Relation To Flour Physicochemical Properties And Bread Qualities, Wipada Wunthunyarat

Graduate Theses and Dissertations

Gluten-free products from rice are gaining popularity among consumers because of its hypoallergenic characteristic. The absence of gluten results in inferior bread qualities such as hard texture, reduced volume and shorter shelf-life, which can be improved by the addition of external hydrolytic enzymes. Hydrolytic enzymes are activated during germination to stimulate plant growth, and hence these enzymes may function similarly to the external enzymes to improve gluten-free bread from brown rice. Therefore, the objective of this work was to investigate the activities of amylases and protease in germinated brown rice (GBR) from long-grain and short-grain rices under different germination conditions …

Control Of Protoporphyrinogen Oxidase-Resistant Palmer Amaranth, Michael Mckinley Houston

Graduate Theses and Dissertations

Already one of the most troublesome weeds in row crop production in the southern U.S., protoporphyrinogen oxidase (PPO)-resistant Palmer amaranth [Amaranthus palmeri (S.) Wats.] was first documented in Arkansas in 2015. Since this confirmation, PPO-resistant Palmer amaranth has been identified throughout the Midsouth. The following research evaluated both current and future herbicide programs for controlling PPO-resistant Palmer amaranth and quantified field-level resistance to PPO-inhibiting herbicides. On-farm research, located in fields with confirmed PPO-resistant Palmer amaranth, was conducted in 2016 and 2017. In preemergence (PRE) herbicide experiments, PPO-inhibiting herbicides still proved useful when combined with herbicides such as metribuzin and/or pyroxasulfone. …

Detection Of Novel Allelic Variations In Soybean Mutant Population Using Tilling By Sequencing, Reneth Millas, Mary Espina, C. M. Sabbir Ahmed, Angelina Bernardini, Ekundayo Adeleke, Zeinab Yadegari, Korsi Dumenyo, Ali Taheri

Agricultural and Environmental Sciences Faculty Research

One of the most important tools in genetic improvement is mutagenesis, which is a useful tool to induce genetic and phenotypic variation for trait improvement and discovery of novel genes. JTN-5203 (MG V) mutant population was generated using an induced ethyl methane sulfonate (EMS) mutagenesis and was used for detection of induced mutations in FAD2-1A and FAD2-1B genes using reverse genetics approach. Optimum concentration of EMS was used to treat 15,000 bulk JTN-5203 seeds producing 1,820 M2 population. DNA was extracted, normalized, and pooled from these individuals. Specific primers were designed from FAD2-1A and FAD2-1B genes that are involved in …

How Do Ecological Resilience Metrics Relate To Community Stability And Collapse?, Caleb P. Roberts, Dirac L. Twidwell Jr, David G. Angeler, Craig R. Allen

Department of Agronomy and Horticulture: Faculty Publications

The concept of ecological resilience (the amount of disturbance a system can absorb before collapsing and reorganizing) holds potential for predicting community change and collapse—increasingly common issues in the Anthropocene. Yet neither the predictions nor metrics of resilience have received rigorous testing. The crossscale resilience model, a leading operationalization of resilience, proposes resilience can be quantified by the combination of diversity and redundancy of functions performed by species operating at different scales. Here, we use 48 years of sub-continental avian community data aggregated at multiple spatial scales to calculate resilience metrics derived from the cross-scale resilience model (i.e., cross-scale diversity, …

Identification Of Loci Controlling Adaptation In Chinese Soya Bean Landraces Via A Combination Of Conventional And Bioclimatic Gwas, Ying-Hui Li, Delin Li, Yong-Qing Jiao, James C. Schnable, Yan-Fei Li, Hui-Hui Li, Huai-Zhu Chen, Hui-Long Hong, Ting Zhang, Bin Liu, Zhang-Xiong Lui, Qing-Bo You, Yu Tian, Yong Guo, Rong-Xia Guan, Li-Juan Zhang, Ru-Zhen Chang, Zhiwu Zhang, Jochen Reif, Xin-An Zhou, Patrick S. Schnable, Li-Juan Qiu

Department of Agronomy and Horticulture: Faculty Publications

Landraces often contain genetic diversity that has been lost in modern cultivars, including alleles that confer enhanced local adaptation. To comprehensively identify loci associated with adaptive traits in soya bean landraces, for example flowering time, a population of 1938 diverse landraces and 97 accessions of the wild progenitor of cultivated soya bean, Glycine soja was genotyped using tGBS. Based on 99 085 high-quality SNPs, landraces were classified into three subpopulations which exhibit geographical genetic differentiation. Clustering was inferred from STRUCTURE, principal component analyses and neighbour-joining tree analyses. Using phenotypic data collected at two locations separated by 10 degrees of latitude, …

Economic Contribution Of The Agricultural Sector To The Arkansas Economy In 2017, Leah English, Jennie Popp, Wayne Miller

AAES Research Reports and Research Bulletins

Agriculture and associated agricultural activities are major contributors to the Arkansas economy. Agriculture is defined as the sum of agricultural production and processing activities, unless otherwise specified, and includes crop and animal production and processing, agricultural support industries, forestry and forest products, and textile goods. Agriculture contributes to the economy through direct agricultural production and value-added processing, and also leads to economic activity in other parts of the economy. This report is the eleventh in a series of reports examining agriculture’s economic contribution to the Arkansas economy. The total economic contribution of agriculture (direct, indirect, and induced effects) on value …

Herbicide Drift Influence On Amaranthus Spp. Herbicide Resistance Evolution, Bruno Canella Vieira

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

The adverse consequences of herbicide drift towards sensitive crops have been extensively reported in the literature. However, no information is available on the consequences of herbicide drift onto weed species inhabiting boundaries of agricultural fields. Exposure to herbicide drift could be detrimental to long-term weed management as several weed species have evolved herbicide resistance after recurrent selection with low herbicide rates. Despite the herbicide drift exposure and its potential implications on resistance evolution and weed management, resistance prone weed species such as Palmer amaranth (Amaranthus palmeri) and waterhemp (Amaranthus tuberculatus) are often neglected and not properly …

Bedstraw Eradication Program: Annual Report To Grain Growers 2018/2019, Department Of Primary Industries And Regional Development, Western Australia

Biosecurity published reports

The Grains, Seeds and Hay Industry Management Committee (GSHIMC) believes the current program is delivering the best value for the funding provided and is achieving the project outcomes of containment and eradication.

Approved programs are developed annually for each infested property in consultation with GSHIMC, the Department of Primary Industries and Regional Development (DPIRD) and the landholders detailing management actions, estimated costs and timeframes of the agreed actions.

The two infested properties have now entered the final Release Phase of a nine-year eradication program. The program is implemented by DPIRD and includes six consecutive years of winter spray treatments, followed …

Simultaneous Gains In Grain Yield And Nitrogen Efficiency Over 70 Years Of Maize Genetic Improvement, Sarah M. Mueller, Carlos D. Messina, Tony J. Vyn

Purdue University Libraries Open Access Publishing Fund

The competing demands of increasing grain yields to feed a growing population and decreasing nitrogen (N) fertilizer use and loss to the environment poses a grand challenge to farmers and society, and necessitates achieving improved N use efficiency (NUE) in cereal crops. Although selection for increased yield in maize has improved NUE over time, the present understanding of the physiological determinants of NUE and its key components hampers the design of more effective breeding strategies conducive to accelerating genetic gain for this trait. We show that maize NUE gains have been supported by more efficient allocation of N among plant …

Climate Change Impacts On Winter Wheat Yield In Northern China, Xiu Geng, Fang Wang, Wei Ren, Zhixin Hao

Plant and Soil Sciences Faculty Publications

Exploring the impacts of climate change on agriculture is one of important topics with respect to climate change. We quantitatively examined the impacts of climate change on winter wheat yield in Northern China using the Cobb–Douglas production function. Utilizing time-series data of agricultural production and meteorological observations from 1981 to 2016, the impacts of climatic factors on wheat production were assessed. It was found that the contribution of climatic factors to winter wheat yield per unit area (WYPA) was 0.762–1.921% in absolute terms. Growing season average temperature (GSAT) had a negative impact on WYPA for the period of 1981–2016. A …

Biomethane Production From Distillery Wastewater, Zachary Christman

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

Distillery wastewater treatment is a great ecological problem, for example, India produces 2.7 billion liters of alcohol that results in 40 billion liters of wastewater. However, this material can be seen as a resource since 11 million cubic meters of biogas at 60% methane could be produced in addition to cleaning the water. The distillery has two options of what to do with the biogas. The first is to use the biogas to fuel the distillery making the production plant more energy efficient and removing some of the need to buy natural gas. The other is to upgrade the biogas …

Frost Identification Guide For Canola And Pulses, Ben Biddulph, Department Of Primary Industries And Regional Development, Western Australia

Bulletins 4000 -

Frost damage reduces crop yield and grain quality. Early identification of symptoms allows timely crop salvage decisions to be made.

Evaluation Of Host Resistance And The Utilization Of Organic Amendments To Manage Macrophomina Crown Rot Of Strawberry In California, Jonathan W. Winslow

Master's Theses

The production of strawberries can be severely limited by soilborne plant pathogens, insects and weeds. Macrophomina phaseolina is a problematic soilborne fungal pathogen in California strawberry production inciting the disease Macrophomina crown rot. When established, the pathogen can cause extensive plant decline and mortality. Host resistance will be a critical tool for managing this disease and guiding breeding programs in the post methyl bromide era. Evaluation of host resistance in strawberry germplasm to M. phaseolina was evaluated through phenotypic assessments of disease incidence. A total of 90 strawberry cultivars and elite selections were included in a replicated field trial conducted …

Application Of Loop-Mediated Isothermal Amplification In An Early Warning System For Epidemics Of An Externally Sourced Plant Virus, Benjamin S. Congdon, Paul Matson, Farhana Begum, Monica Kehoe, Brenda A. Coutts

Biosecurity Research Articles

Restricting Turnip yellows virus (TuYV) spread in canola (Brassica napus) crops often relies upon the application of systemic insecticides to protect young vulnerable plants from wide-scale green-peach aphid (GPA; Myzus persicae) colonization and subsequent virus infection. For these to be applied at the optimal time to ensure they prevent epidemics, growers would need to be forewarned of incoming viruliferous aphid migration and colonization. This study was conducted to field validate a loop-mediated isothermal amplification (LAMP) protocol designed to detect TuYV in aphids caught on traps and develop an early warning system for TuYV epidemics. Double-sided yellow sticky traps were deployed …

Introduction To Sorghum Paper Production, Zachary Christman

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

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.

Macronutrient Content Of Winter Annual Cereal Grains With Phosphorus Fertilization, Taylor Anne Young

Graduate Theses/Dissertations

Missouri ranks third in the United States in cow-calf production, and much of the land these cattle graze has acidic soil that is low in plant available phosphorus (P). Proper soil fertility is important to ensure that these forages meet the nutritional requirements of cattle. Tall fescue (Festuca arundinaceum (Schreb.)), has been shown to respond to increased soil P levels with increased growth and leaf concentrations of P, calcium (Ca), magnesium (Mg), and potassium (K). It is unknown if winter annual cereals will respond similarly. The objective of this study is to examine cereal rye (Secale cereal L.), winter wheat …