Agriculture Commons^™

Identification And Utilization Of Genetic Determinants Of Trait Measurement Errors In Image-Based, High-Throughput Phenotyping, Yan Zhou, Aaron Kusmec, Seyed Vahid Mirnezami, Lakshmi Attigala, Srikant Srinivasan, Talukder Zaki Jubery, James Schnable, Maria G. Salas Fernandez, Baskar Ganapathysubramanian, Patrick S. Schnable

Department of Agronomy and Horticulture: Faculty Publications

The accuracy of trait measurements greatly affects the quality of genetic analyses. During automated phenotyping, trait measurement errors, i.e., differences between automatically extracted trait values and ground truth, are often treated as random effects that can be controlled by increasing population sizes and/or replication number. By contrast, there is some evidence that trait measurement errors may be partially under genetic control. Consistent with this hypothesis, we observed substantial non-random, genetic contributions to trait measurement errors for five maize (Zea mays) tassel traits collected using an image-based phenotyping platform. The phenotyping accuracy varied according to whether a tassel exhibited …

A Decision Tool To Identify Population Management Strategies For Common Ravens And Other Avian Predators, Andrea F. Currylow, Brenda J. Hanley, Kerry L. Holcomb, Timothy Shields, Stephen Boland, William I. Boarman, Mercy Vaughn

Human–Wildlife Interactions

Some avian species have developed the capacity to leverage resource subsidies associated with human manipulated landscapes to increase population densities in habitats with naturally low carrying capacities. Elevated corvid densities and new territory establishment have led to an unsustainable increase in depredation pressure on sympatric native wildlife prey populations as well as in crop damage. Yet, subsidized predator removal programs aimed at reducing densities are likely most effective longer-term when conducted in tandem with subsidy control, habitat management, and robust assessment monitoring programs. We developed decision support software that leverages stage structured Lefkovitch population matrices to compare and identify treatment …

Incorporation Of Summer Annual Mixtures Into Grazing Systems In Kentucky, Kelly Marie Mercier

Theses and Dissertations--Plant and Soil Sciences

Utilizing summer annual grass-legume forage mixtures has the potential to improve forage yield and nutritive characteristics, and/or animal performance during times when cool-season pasture growth is limited by high temperatures. Legumes can utilize atmospheric nitrogen, which can increase crude protein and forage digestibility in mixtures. As nitrogen application generally improves both the yield and nutritive characteristics of summer annual forages, but can have a negative effect on legume competitiveness, nitrogen fertilizer recommendations for legume-containing summer annual mixtures are not well established.

Two experiments were conducted to determine the feasibility of utilizing summer annual mixtures in Kentucky, USA. The first experiment …

Pheromone Antagonism In Plutella Xylostella (Linnaeus) By Sex Pheromones Of Two Sympatric Noctuid Moths, Fu Min Wang, Zhi Jie Shen, Coby Schal, Junwei J. Zhu, Guo Xin Zhou, Yu Lei Wang, Ji Rui Wang, Jian Yu Deng, Nian Feng Wan

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

BACKGROUND: Responses to sex pheromones are commonly antagonized by pheromone components of closely related species. Pheromone antagonism has not been widely explored for phylogenetically distant species that have completely different pheromone components. Yet, pheromone components of sympatrically occurring species may also interfere with each other even if these species are distantly related. Here, the effects of heterospecific pheromones on electrophysiology (electroantennogram, EAG) and behavioral responses were tested on the diamondback moth Plutella xyloslella (Plutellidae) and two sympatric noctuid moth species, Spodoptera litura and Spodoptera exigua, whose larvae also feed on Brassica crops.

RESULTS: The sex pheromone blend of P. xyloslella, …

Forages For Conservation And Improved Soil Quality, John F. Obrycki, Douglas L. Karlen

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

Forages provide several soil benefits, including reduced soil erosion, reduced water runoff, improved soil physical properties, increased soil carbon, increased soil biologic activity, reduced soil salinity, and improved land stabilization and restoration when grown continuously or as part of a crop rotation. Ongoing research and synthesis of knowledge have improved our understanding of how forages alter and protect soil resources, thus providing producers, policymakers, and the general public information regarding which forage crops are best suited for a specific area or use (e.g. hay, grazing or bioenergy feedstock). Forages can be produced in forestland, range, pasture, and cropland settings. These …

Antibacterial Activities Of Nepetalactones Against Public Health-Related Pathogens, Anuradha Ghosh, Enya V. Zhu, Haichuan Wang, Ludek Zurek, Junwei J. Zhu

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

The antimicrobial activities of (Z,E)- and (E,Z)-nepetalactones, 2 major compositional compounds from the essential oil of catnip (Nepeta cataria), were first discovered from fly larval development media studies with over 98% inhibition of bacterial growth. Further investigation demonstrated inhibition of the growth of various bacterial species of public health significance. Catnip oil showed antibacterial activity against 5 Gram-positive and 9 Gram-negative bacteria. The antimicrobial activity varied among the original essential oil from the plant and its major compositional compounds as a blended mixture or an individual compound. Growth inhibition was observed against 5 Neisseria species, with particularly strong inhibition against …

Evaluation Of Leaf Spot Resistance In Wild Arachis Species Of Section Arachis, Alicia Massa, Renee Arias, Ronald B. Sorensen, Victor S. Sobolev, S. P. Tallury, H. T. Stalker, Marshall Lamb

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

Wild diploid Arachis species are potential sources of resistance to early (ELS) and late (LLS) leaf spot diseases caused by Passalora arachidicola (syn. Cercospora arachidicola Hori), and Nothopassalora personata (syn. Cercosporidium personatum (Berk. & Curt.) Deighton), respectively. Within section Arachis, limited information is available on the extent of genetic variation for resistance to these fungal pathogens. A collection of 78 accessions representing 15 wild species of Arachis section Arachis from the U.S peanut germplasm collection was evaluated for resistance to leaf spots. Screening was conducted under field (natural inoculum) conditions in Dawson, Georgia, during 2017 and 2018. Accessions differed …

Planting Depth And Within-Field Soil Variability Impacts On Corn Stand Establishment And Yield, Stirling Stewart, Newell Kitchen, Matt Yost, Lance Stephen Conway, Paul Carter

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

Seedbed conditions during corn (Zea mays L.) planting can have substantial impact on corn stand establishment and final yield. Planting management decisions are complex due to spatial variability caused by changing soil characteristics such as soil texture or landscape position. Field experiments conducted in central Missouri from 2017 to 2019 assessed the effects of varying corn planting depths on stand establishment and yield. Sites included fine- and coarse-textured alluvial soils, and summit, back, and foot slope positions of Alfisol claypan soil landscapes. On alluvial soil, deep planting (7.6 cm) often had the most uniform and timely emergence. Shallow planting (3.8 …

In Vitro Digestibility Of Forages Incubated With Equine Fecal Inoculum Stored Under Varying Conditions, Shianne K. Walther

Graduate Theses/Dissertations

This study evaluated the in vitro effect on digestibility of forages when incubated with microbial inoculum formed from equine feces stored under varying conditions. Fecal material was stored at four storage conditions of 12˚C for 6 hours, 12˚C for 12 hours, 23˚C for 6 hours and 23˚C for 12 hours under aerobic conditions. Stored fecal material was used to form microbial inoculum for use in an ANKOM Daisy II Incubator. Nine different forage samples were digested in the ANKOM Daisy II Incubator to evaluate interactions between storage condition of microbial inoculum and chemical composition of digested forage samples. Forage samples …

Pumping Fees And Spillovers In The Groundwater Commons: An Evaluation Of A Conservation Tool And Irrigator Competitive Behavior, Godwin Kwabla Ekpe

Graduate Research Theses & Dissertations

My dissertation examines the effectiveness of pumping fees in groundwater commons agricultural irrigation as a conservation tool in the presence of varying water scarcity levels and spatial interdependence among irrigators. The first chapter provides a brief overview of three important areas of groundwater commons irrigation addressed in this dissertation. The second chapter’s objectives are two-fold. First, I review the common-pool resources literature relative to concerns of sustainable extraction and implementation of conservation policies focusing on pricing incentives in the management of groundwater commons where irrigators share the same underlying aquifer. Second, I introduce a theoretical model involving incorporating a non-constant …

Genetically Modified Corn Diffusion And Biofuel Usage: Impacts On Corn Belt Cropping Systems Changes, Kenneth Annan

Electronic Theses and Dissertations

The adoption of genetically modified (GM) crops, the rise of ethanol production that produced an additional derived demand for corn, and the increasingly prominent position of corn and soybeans in crop rotations embody major changes in U.S. agriculture during the past decades. This study investigates the linkages among these developments in two ways. First, we look at how biotechnology and biofuels have influenced cropping system changes in the Corn Belt region of the United States, using state-level data from 2000 to 2019. Second, we investigate the determinants of corn acreage intensification levels and heterogeneity at the state level using data …

Interrogating The Socio-Ethical Dilemmas Of Precision Agriculture Technologies, Ayorinde Ogunyiola

Electronic Theses and Dissertations

Farming has moved into a digital age where data and information are available to farmers to make informed agronomic and financial on-farm decisions. The development of precision agriculture (PA), such as big data technologies and machine learning algorithms is transforming the agricultural food production system in diverse ways, economically, environmentally, and socially. Despite benefits afforded by PA to agricultural productivity and environmental sustainability, these technologies can raise unintended societal challenges that can also limit their adoption among farmers. PA is changing how farming is done, reconstructing farmers’ social identities, and influencing relationships between farmers, agronomists, and technology developers. This dissertation …

Quantifying The Impacts Of An Integrated Crop-Livestock System On Plant Nutrient Accumulation, Crop Yield, And Economic Performance, Teerath Singh Rai

Electronic Theses and Dissertations

Integrated crop-livestock systems (ICLs), if managed properly, have the potential for enhancing crop production and economics. Cover crops in ICL can be grazed to provide feed for livestock and improve nutrient recycling. This dissertation focused on assessing the impacts of ICL on crop yield and economics using field and modeling studies. Specific objectives of this dissertation are: (i) evaluating the impacts of the ICL on crop yield, and economic performance in a 3-yr oat (Avena sativa L.) – maize (Zea mays L.) – soybean (Glycine max (L.) Merr.) rotation, (ii) assessing the impacts of the ICL on maize biomass accumulation, …

Valorization Of Xylan In Agroforestry Waste Streams, Harrison Appiah

Graduate Theses, Dissertations, and Problem Reports (ETD)

Valorization of Xylan in Agroforestry Waste Streams.

Harrison Appiah

Microwave-assisted deep eutectic solvent and gamma-valerolactone metallic chloride catalyzed conversion of xylan to furfural were investigated using a 2x3 factorial experimental design at two levels of percent microwave power, reaction time, and catalyst concentration. The levels of each factor studied were (20%, 60% microwave power, 2, 4 minutes, and 10, 20mg) respectively. The effect of three metallic chloride catalysts (LiCl, FeCl3.6H20, CuCl2) on the conversion of xylan to furfural was also investigated. The gamma-valerolactone-ferric chloride sent system exhibited the highest mean yield of furfural (56.50%). The next highest furfural yield of …

Soil Response Of Helicopter Liming In The Monongahela National Forest, Jarrett Douglas Fowler

Graduate Theses, Dissertations, and Problem Reports (ETD)

Soils in the Monongahela National Forest (MNF) are acidic due to sandstone parent material, acid deposition, uptake of base cations by vegetation, and release of organic acids by organic matter (OM) decomposition. Increases in soil acidity have caused declines in forest health and changed species composition and nutrient status. Liming can neutralize soil acidity, but no large-scale liming projects have been done on acid forest soils in the USA. In anticipation of acquiring funding for a proposed liming project in the MNF, in 2007 and 2009 10 sites were selected to sample and analyze soils before lime was applied. In …

Plant Species Identification In The Wild Based On Images Of Organs, Meghana Kovur

Graduate Theses, Dissertations, and Problem Reports (ETD)

Image-based plant species identification in the wild is a difficult problem for several reasons. First, the input data is subject to a very high degree of variability because it is captured under fully unconstrained conditions. The same plant species may look very different in different images, while different species can often appear very similar, challenging even the recognition skills of human experts in the field. The large intra-class and small inter-class image variability makes this a fine-grained visual classification problem. One way to cope with this variability and to reduce image background noise is to predict species based on the …

Estimating Food Waste Due To Food Safety Recalls And Investigating Ways To Minimize Negative Impacts, Mykayla Latronica

Master's Theses

For years the issue of food waste has been recognized and quantified; however, food safety issues often go unrecognized as a source of food waste. One objective of this research is to estimate quantities and monetary value of fruits and vegetables implicated in food safety recalls, and thus wasted. Using publicly available data we identified all recalls involving vegetable or fruit commodities contaminated with Listeria monocytogenes, pathogenic E. coli, or Salmonella during 2015-2018. When quantities were provided, monetary value of recalled product was calculated using USDA ERS 2016 average retail prices. Although data limitations only allowed analysis of …

Midwestern U.S. Diurnal Temperature Range: Spatial And Temporal Trends From 1900-2018, Kelly Ann Swaney

Graduate Research Theses & Dissertations

In the Corn Belt region of the United States, the twentieth century saw many land use changes as the land had been converted from the natural landscape to cropland. As the twentieth century progressed, numerous advancements occurred to increase the crop acreage, crop density, and amount of irrigated land. All of these changes contributed to higher rates of evapotranspiration, which put more moisture into the low levels of the atmosphere. This additional moisture played a role in changing the radiative fluxes and, as a result, the surface temperature. The Diurnal Temperature Range (DTR) is examined across the 1900 to 2018 …

On The Use Of Virtual Reality In Mitigating Hypothetical Bias In Choice Experiments, Di Fang, Rodolfo M. Nayga Jr., Grant H. West, Claudia Bazzani, Wei Yang, Benjamin C. Lok, Charles E. Levy, Heather A. Snell

Agricultural Economics and Agribusiness Faculty Publications and Presentations

Choice experiments have been extensively used in many stated preference studies and disciplines. In order to give external validity to stated preferences, participants must behave the same in an experiment setting as they do in reality. The difference between a decision made in a real experiment and a hypothetical experiment is commonly attributed to "hypothetical bias." In this paper, we investigate whether virtual reality can reduce hypothetical bias in choice experiments. We conducted a set of experiments using the Food and Drug Administration's new Nutrition Facts Label for yogurts. Participants were randomly assigned to non-hypothetical and hypothetical experiments, which differed …

Weeds As Hosts Of Plant Parasitic Nematodes In Subtropical Agriculture Systems, Habraham F. Lopez, Pushpa Soti, Ganpati B. Jagdale, Parwinder Grewal, Alexis Racelis

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

With a nearly year-round growing season, tropical and subtropical regions are plagued with a myriad of agro-nomic challenges, including near-continuous weeds and invertebrate pests including plant-parasitic nematodes (PPNs). A poor understanding of the presence and geographical distributions of these pests complicate their man-agement, especially in organic farming systems. This work attempts to document the interaction of PPNs with the major weeds in the semi-arid region of south Texas. Five organically managed farms were surveyed for four weeds of regional agronomic importance including silverleaf nightshade (Solanum elaeagnifolium), common sunflower (Helianthus annuus), false ragweed (Parthenium hysterophorus), and London rocket (Sisymbrium irio). Soil …