Agronomy and Crop Sciences Commons^™

The Effects Of Fungicide And Genetics On Fungal Diseases On Wheat In Nebraska With Emphasis On Stem Rust, Javed Sidiqi

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

Foliar fungal diseases of wheat (Triticum aestivum L.) pose a serious threat to wheat production. Despite the significant progress that has been made limiting major fungal diseases by developing resistant cultivars, these diseases challenge the economic sustainability of wheat production. The objectives of this research were (1) To determine the effect of fungal plant pathogens on grain yield in eastern Nebraska, released and pre-release winter wheat genotypes were studied in fungicide treated and untreated plots from 2015 to 2017. (2) To determine if Sr7b is present using allelism tests in ‘Gage’ wheat as previously hypothesized.

Sixty genotypes were planted …

Field Pea Response To Seeding Rate, Depth, And Inoculant In West-Central Nebraska, Strahinja V. Stepanovic, Charles Burr, Julie A. Peterson, Daran Rudnick, Cody F. Creech, Rodrigo Werle

West Central Research and Extension Center, North Platte

Increased market demand and larger adoption of field pea (Pisum sativum L.) in semiarid west-central Nebraska has provided opportunities to replace summer fallow and diversify crop rotations. As a relatively new crop, its response to different seeding practices has not been evaluated in this eco-region. Field pea grain yield response to seeding depth (25, 50, and 75 mm), inoculation with Rhizobium leguminosarum bv. viciae (yes and no rhizobia inoculant), and seeding rates (35, 50, 65, 75, 90, 105, and 120 plants m^–2) was investigated in 2015 and 2016 at five sites in Perkins County, NE. There were …

Determining The Light Requirements Of Various Turfgrass Systems And Investigating Techniques To Quantify Photosynthetically Active Radiation, Travis Russell

Graduate Theses and Dissertations

Light is one of the primary growth-limiting factors of turfgrass. Without sufficient quantities of photosynthetically active radiation (PAR; 400-700 nm wavelength), turfgrass quality will decline and could ultimately result in plant death. PAR light can be expressed in a daily quantity known as the daily light integral (DLI) and has been utilized to determine minimum light requirements for turfgrass as well as other plants. With an estimated 25% of all turfgrass being maintained under some level of shaded conditions, it is imperative to define minimum DLI requirements of various turfgrass systems to ensure acceptable turf quality. In addition, it is …

Arkansas Soybean Research Studies 2016, Jeremy Ross

Arkansas Agricultural Experiment Station Research Series

Arkansas is the leading soybean-producing state in the mid-southern United States. Arkansas ranked 11th in soybean production in 2016 when compared to the other soybean-producing states in the U.S. The state represents 3.4% of the total U.S. soybean production and 3.8% of the total acres planted to soybean in 2016. The 2016 state soybean average was 47 bushels per acre, 2.5 bushels per acre less than the state record soybean yield set in 2014. The top five soybean-producing counties in 2016 were Mississippi, Phillips, Poinsett, Crittenden, Arkansas Counties. These five counties accounted for 34.7% of soybean production in Arkansas in …

Testing The Potential Of Novel Grain Crop Cultivation In Rural Malawi During The Dry Season Through Irrigation And Soil Modification, Jessica Truman

Undergraduate Honors Theses

This research project studied the germination and growth rates of oat and quinoa crops in Mtalimanja, Malawi. This project was part of a larger effort by General Mills and Brigham Young University researchers to increase the diversity and nutrient content of crops in impoverished countries worldwide. It was conducted from May to August 2017 during Malawi’s dry season. Tetraploid oats and quinoa, both modified to increase the protein content of harvested grains, were planted under three different soil conditions: unamended soil, soil mixed with composted chicken litter, and soil with surface-applied granular fertilizer. The research plots were watered daily except …

Impacts Of Cover Crop And Residue Removal On Soil Hydraulic And Thermal Properties, Michael T. Sindelar

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

Large-scale crop residue removal for livestock or biofuel production may negatively affect soil and water resources. A combination of management practices could be the key to manage such resources under increasingly variable climate. For instance, use of cover crops (CCs) could offset the negative impacts that corn (Zea mays L.) residue removal may have on soil water and energy balance. We studied: 1) the effect of corn residue removal (56%) with and without winter rye (Secale cereale L.) CC on soil hydraulic and thermal properties including water infiltration, water retention, pores-size distribution, thermal conductivity, specific heat capacity, and …

Vegetation And Soil Responses To Concrete Grinding Residue Application On Highway Roadsides Of Eastern Nebraska, Ana Wingeyer, Martha Mamo, Walter H. Schacht, Dennis L. Mccallister, Pamela Sutton

Department of Agronomy and Horticulture: Faculty Publications

As a precautionary principle, the National Pollutant Discharge Elimination System (NPDES) permit establishes that the primary pollutant in concrete grinding residue (CGR) is its alkalinity and restricts CGR roadside discharge to 11 Mg ha⁻¹ or the agronomic liming rate, whichever is lower. We evaluated the effect of CGR application on roadside soil chemical properties, existing vegetation, and rainfall runoff. Five CGR rates (0, 11, 22, 45, and 90 dry Mg ha⁻¹) were tested on roadsides slopes at two different locations in eastern Nebraska. Vegetation, soil, and runoff characteristics were evaluated before CGR application and 30 d and …

A Systems Modeling Approach To Forecast Corn Economic Optimum Nitrogen Rate, Laila A. Puntel, John E. Sawyer, Daniel W. Barker, Peter J. Thorburn, Michael J. Castellano, Kenneth J. Moore, Andy Vanloocke, Emily A. Heaton, Sotirios V. Archontoulis

Department of Agronomy and Horticulture: Faculty Publications

Historically crop models have been used to evaluate crop yield responses to nitrogen (N) rates after harvest when it is too late for the farmers to make in-season adjustments. We hypothesize that the use of a crop model as an in-season forecast tool will improve current N decision-making. To explore this, we used the Agricultural Production Systems sIMulator (APSIM) calibrated with long-term experimental data for central Iowa, USA (16-years in continuous corn and 15-years in soybean-corn rotation) combined with actual weather data up to a specific crop stage and historical weather data thereafter. The objectives were to: (1) evaluate the …

The Effect Of Two Planting Dates And Methods On Snap Bean (Phaseolus Vulgaris) Production In A Tunnel House, Edward Sparks, Victor Khan, Ramble Ankumah, James E. Currington, Nathaniel Ellison, George X. Hunter Jr., Jeffery Moore

Professional Agricultural Workers Journal

The study was conducted to evaluate the impact of two planting dates and methods on snap bean yields in a tunnel house. The main plots included planting dates March 17 and 31, 2016 for first and second plantings. The sub-plots consisted of planting Method 1 where one seed per hill was planted every 4” apart, and planting Method 2 where three seeds per hill were planted every 12” apart; each treatment combination was replicated four times. The results of the study showed that it took 55 days for the snap beans to be ready for harvest for both planting dates. …

Review Of Genome-Wide Association Studies: From Polymorphism To Personalized Medicine, Jinliang Yang

Department of Agronomy and Horticulture: Faculty Publications

Genome-wide association studies (GWAS) has become a powerful tool in the area of quantitative genetics to map the relationship between trait and genomic variations. This volume provides a great resource for beginners to learn about the recent advances in GWAS and for domain experts to identify the gaps in the area. The first part of the volume lays out the statistical background of GWAS. I really liked the article by Yang et al., Introduction to Statistical Methods in Genome-Wide Association Studies. In this chapter, the authors talked about the missing heritability issue and introduced ways to calculate heritability using the …

Arkansas Cotton Variety Test 2017, Fred Bourland, W. Barnett, C. Kennedy, L. Martin, A. Rouse, B. Robertson

Arkansas Agricultural Experiment Station Research Series

The primary goal of the Arkansas Cotton Variety Test is to provide unbiased data regarding the agronomic performance of cotton varieties and advanced breeding lines in the major cotton-growing areas of Arkansas.

An Epigenetic Breeding System In Soybean For Increased Yield And Stability, Sunil K. Kenchanmane Raju, Mon-Ray Shao, Robersy Sanchez, Ying-Zhi Xu, Ajay Sandhu, George L. Graef, Sally A. Mackenzie

Department of Agronomy and Horticulture: Faculty Publications

Epigenetic variation has been associated with a wide range of adaptive phenotypes in plants, but there exist few direct means for exploiting this variation. RNAi suppression of the plant-specific gene, MutS HOMOLOG1 (MSH1), in multiple plant species produces a range of developmental changes accompanied by modulation of defence, phytohormone and abiotic stress response pathways along with methylome repatterning. This msh1-conditioned developmental reprogramming is retained independent of transgene segregation, giving rise to transgene-null ‘memory’ effects. An isogenic memory line crossed to wild type produces progeny families displaying increased variation in adaptive traits that respond to selection. This study …

Inheritance Of Mesotrione Resistance In An Amaranthus Tuberculatus (Var. Rudis) Population From Nebraska, Usa, Maxwel C. Oliveira, Todd A. Gaines, Amit J. Jhala, Stevan Z. Knezevic

Department of Agronomy and Horticulture: Faculty Publications

A population of Amaranthus tuberculatus (var. rudis) evolved resistance to 4- hydroxyphenylpyruvate dioxygenase (HPPD) inhibitor herbicides (mesotrione, tembotrione, and topramezone) in Nebraska. The level of resistance was the highest to mesotrione, and the mechanism of resistance in this population is metabolism-based likely via cytochrome P450 enzymes. The increasing number of weeds resistant to herbicides warrants studies on the ecology and evolutionary factors contributing for resistance evolution, including inheritance of resistance traits. In this study, we investigated the genetic control of mesotrione resistance in an A. tuberculatus population from Nebraska, USA. Results showed that reciprocal crosses in the F1 families exhibited …

Genome-Wide Analysis Of Grain Yield Stability And Environmental Interactions In A Multiparental Soybean Population, Alencar Xavier, Diego Jarquin, Reka Howard, Vishnu Ramasubramanian, James E. Specht, George L. Graef, William D. Beavis, Brian W. Diers, Qijian Song, Perry B. Cregan, Randall L. Nelson, Rouf Mian, J. Grover Shannon, Leah K. Mchale, Dechun Wang, William Schapaugh, Aaron J. Lorenz, Shizhong Xu, William M. Muir, Katy M. Rainey

Department of Agronomy and Horticulture: Faculty Publications

Genetic improvement toward optimized and stable agronomic performance of soybean genotypes is desirable for food security. Understanding how genotypes perform in different environmental conditions helps breeders develop sustainable cultivars adapted to target regions. Complex traits of importance are known to be controlled by a large number of genomic regions with small effects whose magnitude and direction are modulated by environmental factors. Knowledge of the constraints and undesirable effects resulting from genotype by environmental interactions is a key objective in improving selection procedures in soybean breeding programs. In this study, the genetic basis of soybean grain yield responsiveness to environmental factors …

Overlapping Residual Herbicides For Control Of Photosystem (Ps) Ii- And 4-Hydroxyphenylpyruvate Dioxygenase (Hppd)-Inhibitor-Resistant Palmer Amaranth (Amaranthus Palmeri S. Watson) In Glyphosate-Resistant Maize, Parminder S. Chahal, Zahoor Ahmad Ganie, Amit J. Jhala

Department of Agronomy and Horticulture: Faculty Publications

A Palmer amaranth (Amaranthus palmeri S. Watson) biotype has evolved resistance to photosystem (PS) II- (atrazine) and 4-hydroxyphenylpyruvate dioxygenase (HPPD)-inhibiting herbicides (mesotrione, tembotrione, and topramezone) in maize seed production field in Nebraska, USA. The objectives of this study were to determine the effect of soil residual pre-emergence (PRE) herbicides followed by (fb) tank-mixture of residual and foliar active post-emergence (POST) herbicides on PS-II- and HPPD-inhibitor-resistant Palmer amaranth control, maize yield, and net economic returns. Field experiments were conducted in a grower’s field infested with PS II- and HPPD-inhibitor-resistant Palmer amaranth near Shickley in Fillmore County, Nebraska, USA in 2015 …

Chitosan Biopolymer Promotes Yield And Stimulates Accumulation Of Antioxidants In Strawberry Fruit, Mosaddiqur Rahman, Julakha Akter Mukta, Abdullah As Sabir, Dipall Rani Gupta, Mohammed Mohi-Ud-Din, Mirza Hasanuzzaman, Md. Giashuddin Miah, Mahfuzur Rahman, Md Tofazzai Islam

Faculty & Staff Scholarship

Strawberry is a well-known source of natural antioxidants with excellent free radical scav- enging capacity. This study determined the effects of chitosan application in field condition on plant growth, fruit yield and antioxidant activities in strawberry fruit. Foliar applications of chitosan on strawberry significantly increased plant growth and fruit yield (up to 42% higher) compared to untreated control. Increased fruit yield was attributed to higher plant growth, individual fruit weight and total fruit weight/plant due to the chitosan application. Surprisingly, the fruit from plants sprayed with chitosan also had significantly higher contents (up to 2.6- fold) of carotenoids, anthocyanins, flavonoids …

New For Discovery: Scholarworks@Uark, Discovery Editors

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

No abstract provided.

Discovery: The Student Journal Of Dale Bumpers College Of Agricultural, Food And Life Sciences - Volume 19 2018, Several Authors

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

No abstract provided.

A Message From The Department Head Of Horticulture And Food Science, Wayne Mackey

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

No abstract provided.

Optimising The Identification Of Causal Variants Across Varying Genetic Architectures In Crops, Chenyong Miao, Jinliang Yang, James C. Schnable

Department of Agronomy and Horticulture: Faculty Publications

Association studies use statistical links between genetic markers and the phenotype variation across many individuals to identify genes controlling variation in the target phenotype. However, this approach, particularly conducted on a genome-wide scale (GWAS), has limited power to identify the genes responsible for variation in traits controlled by complex genetic architectures. In this study, we employ real-world genotype datasets from four crop species with distinct minor allele frequency distributions, population structures and linkage disequilibrium patterns. We demonstrate that different GWAS statistical approaches provide favourable trade-offs between power and accuracy for traits controlled by different types of genetic architectures. FarmCPU provides …

Transcriptional Reprogramming Of Legume Genomes: Perspective And Challenges Associated With Single-Cell And Single Cell-Type Approaches During Nodule Development, Marc Libault

Department of Agronomy and Horticulture: Faculty Publications

Transcriptomic approaches revealed thousands of genes differentially or specifically expressed during nodulation, a biological process resulting from the symbiosis between leguminous plant roots and rhizobia, atmospheric nitrogen-fixing symbiotic bacteria. Ultimately, nodulation will lead to the development of a new root organ, the nodule. Through functional genomic studies, plant transcriptomes have been used by scientists to reveal plant genes potentially controlling nodulation. However, it is important to acknowledge that the physiology, transcriptomic programs, and biochemical properties of the plant cells involved in nodulation are continuously regulated. They also differ between the different cell-types composing the nodules. To generate a more accurate …

First Case Of Glufosinate-Resistant Rigid Ryegrass (Lolium Rigidum Gaud.) In Greece, Ilias S. Travlos, Nikolina Cheimona, Rafael De Prado, Amit J. Jhala, Demosthenis Chachalis, Eleni Tani

Department of Agronomy and Horticulture: Faculty Publications

Repeated applications of the same herbicide(s), which are characterized by the same mode of action, increase selection pressure, which in turn favours the evolution of herbicide-resistant weeds. Glufosinate is a broad-spectrum non-selective herbicide being used for weed control for many years around the world. Rigid ryegrass (Lolium rigidum Gaud.) is an economically important grass weed in Greece. Recent complaints by growers about control failure of rigid ryegrass with glufosinate require further investigation and have been the basis of this study. The objectives of this study were to confirm the existence of glufosinate-resistant L. rigidum in Greece and evaluate the …

Empowerment And Tech Adoption: Introducing The Treadle Pump Triggers Farmers’ Innovation In Eastern Ethiopia, Shimelis Beyene, Teshome H. Regassa, Belaineh Legesse, Martha Mamo, Tsegaye Tadesse

Department of Agronomy and Horticulture: Faculty Publications

In 2013, thirty-eight treadle pumps (TPs) were installed as low-cost technology introduction for small-scale irrigation in eastern Ethiopia. This pilot project also trained six farmers on tube well excavation, as well as the installation and maintenance of pumps. In June 2015, researchers visited nine of the thirty-eight TP villages and found only two TPs functioning as originally installed. The rest were replaced with a new technology developed by the trained farmers. Farmers, empowered by training, gained more control in developing technology options tailored to local needs and conditions of their communities. Adopters of the new technology stated that the limited …

Beyond The Plot: Technology Extrapolation Domains For Scaling Out Agronomic Science, Juan I. Rattalino Edreira, Kenneth G. Cassman, Zvi Hochman, Martin K. Van Ittersum, Lenny Van Bussel, Lieven Claessens, Patricio Grassini

Department of Agronomy and Horticulture: Faculty Publications

Ensuring an adequate food supply in systems that protect environmental quality and conserve natural resources requires productive and resource-efficient cropping systems on existing farmland.Meeting this challenge will be difficult without a robust spatial framework that facilitates rapid evaluation and scaling-out of currently available and emerging technologies. Here we develop a global spatial framework to delineate ‘technology extrapolation domains’ based on key climate and soil factors that govern crop yields and yield stability in rainfed crop production. The proposed framework adequately represents the spatial pattern of crop yields and stability when evaluated over the data-rich US Corn Belt. It also facilitates …

Is Conservation Agriculture A Potential Option For Cereal-Based Sustainable Farming System In The Eastern Indo-Gangetic Plains Of Nepal?, Dipendra Pokharel, Raj Kant Jha, Thakur Prasad Tiwari, Mahesh Kumar Gathala, Hari Krishna Shrestha, Dinesh Panday

Department of Agronomy and Horticulture: Faculty Publications

A decline in land and water productivity, increase in the cost of cultivation, and labor-intensive practices are affecting the cereal-based farming system in Nepal, particularly in the Indo-Gangetic Plains (IGP). Conservation agriculture (CA) practices have been found to be the climate-, energy-, and labor-smart and sustainable agricultural production technologies. Sustainable and Resilient Farming System Intensification (SRFSI) has been working since 2014 in response to the sustainability of the cereal-based (rice–wheat and rice–maize) farming in Sunsari and Dhanusha districts of Nepal. This study was conducted to assess the adoption and scaling up of CA in addition to input usage, production, net …

Impact Of Drought On Chemical Composition And Sugar Yields From Dilute-Acid Pretreatment And Enzymatic Hydrolysis Of Miscanthus, A Tall Fescue Mixture, And Switchgrass, Amber Hoover, Rachel Emerson, Allison Ray, Daniel Stevens, Sabrina Morgan, Marnie Cortez, Robert Kallenbach, Matthew Sousek, Rodney Farris, Dayna Daubaras

Department of Agronomy and Horticulture: Faculty Publications

Environmental factors like drought impact the quality of biomass entering a bioconversion process. Drought often reduces the sugar content in lignocellulosic biomass, which could have economic impacts, particularly when compounded with losses in dry biomass yield; however, the effects on conversion efficiency are not completely understood. This study investigated how drought may impact biomass composition and sugar yields from dilute-acid pretreatment and enzymatic hydrolysis of Miscanthus, a tall fescue mixture, and switchgrass from Nebraska, Missouri, and Oklahoma, respectively, grown as part of Regional Feedstock Partnership field trials. Samples were grown and harvested in 2010 during non-drought conditions and in …

Impaired Phloem Loading In Zmsweet13a,B,C Sucrose Transporter Triple Knock-Out Mutants In Zea Mays, Margaret Bezrutczyk, Thomas Hartwig, Marc Horschman, Si Nian Char, Jinliang Yang, Bing Yang, Wolf B. Frommer, Davide Sosso

Department of Agronomy and Horticulture: Faculty Publications

Crop yield is critical for human nutrition, yet the underlying machinery that ultimately determines yield potential is still not understood. Crop productivity under ideal conditions is determined by the efficiency with which plants intercept light, convert it into chemical energy, translocate photosynthates and convert these to storage products in harvestable organs (Zhu et al., 2010). In many crops, sucrose is the primary form for translocation inside the conduit (i.e. the phloem). A combination of SWEETmediated efflux from phloem parenchyma and subsequent secondary active sucrose import by SUT sucrose/H+ symporters is thought to create the driving force for pressure gradient-driven …

Tetracycline And Sulfonamide Antibiotic Resistance Genes In Soils From Nebraska Organic Farming Operations, Marylynn Cadena, Lisa M. Durso, Daniel N. Miller, Heidi M. Waldrip, B. L. Castleberry, Rhae A. Drijber, Charles S. Wortmann

Department of Agronomy and Horticulture: Faculty Publications

There is widespread agreement that agricultural antibiotic resistance should be reduced, however, it is unclear from the available literature what an appropriate target for reduction would be. Organic farms provide a unique opportunity to disentangle questions of agricultural antibiotic drug use from questions of antibiotic resistance in the soil. In this study, soil was collected from 12 certified organic farms in Nebraska, evaluated for the presence of tetracycline and sulfonamide resistance genes (n = 15 targets), and correlated to soil physical, chemical, and biological parameters. Tetracycline and sulfonamide antibiotic resistance genes (ARGs) were found in soils from all 12 …

Sifting And Winnowing: Analysis Of Farmer Field Data For Soybean In The Us North-Central Region, Spyridon Mourtzinis, Juan I. Rattalino Edreira, Patricio Grassini, Adam C. Roth, Shaun N. Casteel, Ignacio A. Ciampitti, Hans J. Kandel, Peter M. Kyveryga, Mark A. Licht, Laura E. Lindsey, Daren S. Mueller, Emerson D. Nafziger, Seth L. Naeve, Jordan Stanley, Michael J. Staton, Shawn P. Conley

Department of Agronomy and Horticulture: Faculty Publications

Field trials are commonly used to estimate the effects of different factors on crop yields. In the present study, we followed an alternative approach to identify factors that explain field-to-field yield variation, which consisted of farmer survey data, a spatial framework, and multiple statistical procedures. This approach was used to identify management factors with strongest association with on-farm soybean yield variation in the US North Central (NC) region. Field survey data, including yield and management information, were collected over two crop growing seasons (2014 and 2015) from rainfed and irrigated soybean fields (total of 3568 field-year observations). Fields were grouped …

Application Of Machine Learning Methodologies For Predicting Corn Economic Optimal Nitrogen Rate, Zhisheng Qin, D. Brenton Myers, Curtis J. Ransom, Newell R. Kitchen, Sang-Zi Liang, James J. Camberato, Paul R. Carter, Richard B. Ferguson, Fabian G. Fernandez, David W. Franzen, Carrie A. M. Laboski, Brad D. Malone, Emerson D. Nafziger, John E. Sawyer, John F. Shanahan

Department of Agronomy and Horticulture: Faculty Publications

Determination of in-season N requirement for corn (Zea mays L.) is challenging due to interactions of genotype, environment, and management. Machine learning (ML), with its predictive power to tackle complex systems, may solve this barrier in the development of locally based N recommendations. The objective of this study was to explore application of ML methodologies to predict economic optimum nitrogen rate (EONR) for corn using data from 47 experiments across the US Corn Belt. Two features, a water table adjusted available water capacity (AWC_wt) and a ratio of in-season rainfall to AWC_wt (RAWC_wt), were …