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Plant Sciences

University of Nebraska - Lincoln

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2019

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Articles 151 - 180 of 190

Full-Text Articles in Life Sciences

Predicting Longitudinal Traits Derived From High-Throughput Phenomics In Contrasting Environments Using Genomic Legendre Polynomials And B-Splines, Mehdi Momen, Malachy T. Campbell, Harkamal Walia, Gota Morota Jan 2019

Predicting Longitudinal Traits Derived From High-Throughput Phenomics In Contrasting Environments Using Genomic Legendre Polynomials And B-Splines, Mehdi Momen, Malachy T. Campbell, Harkamal Walia, Gota Morota

Department of Agronomy and Horticulture: Faculty Publications

Recent advancements in phenomics coupled with increased output from sequencing technologies can create the platform needed to rapidly increase abiotic stress tolerance of crops, which increasingly face productivity challenges due to climate change. In particular, high-throughput phenotyping (HTP) enables researchers to generate large-scale data with temporal resolution. Recently, a random regression model (RRM) was used to model a longitudinal rice projected shoot area (PSA) dataset in an optimal growth environment. However, the utility of RRM is still unknown for phenotypic trajectories obtained from stress environments. Here, we sought to apply RRM to forecast the rice PSA in control and water-limited …


Can Ratoon Cropping Improve Resource Use Efficiencies And Profitability Of Rice In Central China?, Shen Yuan, Kenneth G. Cassman, Jianliang Huang, Shaobing Peng, Patricio Grassini Jan 2019

Can Ratoon Cropping Improve Resource Use Efficiencies And Profitability Of Rice In Central China?, Shen Yuan, Kenneth G. Cassman, Jianliang Huang, Shaobing Peng, Patricio Grassini

Department of Agronomy and Horticulture: Faculty Publications

Identifying cropping systems with small global warming potential (GWP) per unit of productivity is important to ensure food security while minimizing environmental footprint. During recent decades, double-season rice (DR) systems in central China have progressively shifted into single-crop, middle-season rice (MR) due to high costs and labor requirements of double-season rice. Ratoon rice (RR) has been proposed as an alternative system that reconciliates both high annual productivity and relatively low costs and labor requirements. Here we used onfarm data collected from 240 farmer fields planted with rice in 2016 to evaluate annual energy balance, environmental impact, and net profit of …


Identification Of Climate And Genetic Factors That Control Fat Content And Fatty Acid Composition Of Theobroma Cacao L. Beans, Guiliana M. Mustiga, Joe Morrissey, Joseph Conrad Stack, Ashley Duval, Stefan Royaert, Johannes Jansen, Carolina Bizzotto, Cristiano Villela-Dias, Linkai Mei, Edgar B. Cahoon, Ed Seguine, Jean Philippe Marelli, Juan Carlos Motamayor Jan 2019

Identification Of Climate And Genetic Factors That Control Fat Content And Fatty Acid Composition Of Theobroma Cacao L. Beans, Guiliana M. Mustiga, Joe Morrissey, Joseph Conrad Stack, Ashley Duval, Stefan Royaert, Johannes Jansen, Carolina Bizzotto, Cristiano Villela-Dias, Linkai Mei, Edgar B. Cahoon, Ed Seguine, Jean Philippe Marelli, Juan Carlos Motamayor

Center for Plant Science Innovation: Faculty and Staff Publications

The main ingredients of chocolate are usually cocoa powder, cocoa butter, and sugar. Both the powder and the butter are extracted from the beans of the cacao tree (Theobroma cacao L.). The cocoa butter represents the fat in the beans and possesses a unique fatty acid profile that results in chocolate’s characteristic texture and mouthfeel. Here, we used a linkage mapping population and phenotypic data of 3,292 samples from 420 progeny which led to the identification of 27 quantitative trait loci (QTLs) for fatty acid composition and six QTLs for fat content. Progeny showed extensive variation in fat levels …


Drought-Responsive Genes, Late Embryogenesis Abundant Group3 (Lea3) And Vicinal Oxygen Chelate, Function In Lipid Accumulation In Brassica Napus And Arabidopsis Mainly Via Enhancing Photosynthetic Efficiency And Reducing Ros, Yu Liang, Kai Kang, Lu Gan, Shaobo Ning, Jinye Xiong, Shuyao Song, Lingzhi Xi, Senying Lai, Yongtai Yin, Jianwei Gu, Jun Xiang, Shisheng Li, Baoshan Wang, Maoteng Li Jan 2019

Drought-Responsive Genes, Late Embryogenesis Abundant Group3 (Lea3) And Vicinal Oxygen Chelate, Function In Lipid Accumulation In Brassica Napus And Arabidopsis Mainly Via Enhancing Photosynthetic Efficiency And Reducing Ros, Yu Liang, Kai Kang, Lu Gan, Shaobo Ning, Jinye Xiong, Shuyao Song, Lingzhi Xi, Senying Lai, Yongtai Yin, Jianwei Gu, Jun Xiang, Shisheng Li, Baoshan Wang, Maoteng Li

Center for Plant Science Innovation: Faculty and Staff Publications

Drought is an abiotic stress that affects plant growth, and lipids are the main economic factor in the agricultural production of oil crops. However, the molecular mechanisms of drought response function in lipid metabolism remain little known. In this study, overexpression (OE) of different copies of the drought response genes LEA3 and VOC enhanced both drought tolerance and oil content in Brassica napus and Arabidopsis. Meanwhile, seed size, membrane stability and seed weight were also improved in OE lines. In contrast, oil content and drought tolerance were decreased in the AtLEA3 mutant (atlea3) and AtVOC-RNAi of Arabidopsis and in both …


Assessment Of Cover Crop Management Strategies In Nebraska, Us, Maxwel C. Oliveira, Liberty Butts, Rodrigo Werle Jan 2019

Assessment Of Cover Crop Management Strategies In Nebraska, Us, Maxwel C. Oliveira, Liberty Butts, Rodrigo Werle

West Central Research and Extension Center, North Platte

Adoption of cover crops has the potential to increase agricultural sustainability in the US and beyond. In 2017, a survey was conducted with Nebraska stakeholders in an attempt to evaluate current cover crop management strategies adopted in soybean (Glycine max [L.] Merr.), field corn (Zea mays L.), and seed corn production. Eighty-two Nebraska stakeholders answered the survey, of which 80% identified themselves as growers. Eighty-seven percent of respondents manage cover crops, and the average cover crop ha planted on a per farm basis is 32%. The primary method of establishing cover crops following soybeans and field corn is …


Evaluation Of Foliar Insecticide Application Timing For The Control Of Western Bean Cutworm In Field Corn, 2018, Katharine A. Swoboda-Bhattarai, Samantha R. Daniel, Julie A. Peterson Jan 2019

Evaluation Of Foliar Insecticide Application Timing For The Control Of Western Bean Cutworm In Field Corn, 2018, Katharine A. Swoboda-Bhattarai, Samantha R. Daniel, Julie A. Peterson

West Central Research and Extension Center, North Platte

The objective of this field trial was to determine if application timing affects the efficacy of single applications of foliar insecticides at preventing feeding damage by the western bean cutworm (WBC), an important pest of corn and dry beans in the North American Corn Belt. This study was located at the University of Nebraska- Lincoln’s Henry J. Stumpf International Wheat Center in Perkins County, NE (40.856851°N, −101.701335°W). The experimental design used was an RCB design with a total of 10 treatments (three insecticides applied at three application timings, plus an untreated check) and four replications; the treatment design was an …


Quantifying Signpost Usage By Captive Male White-Tailed Deer, Cassie L. Auxt, Eric S. Michel, Jonathan A. Jenks Jan 2019

Quantifying Signpost Usage By Captive Male White-Tailed Deer, Cassie L. Auxt, Eric S. Michel, Jonathan A. Jenks

The Prairie Naturalist

White-tailed deer (Odocoileus virginianus) use rubbing of signpost structures to communicate during the breeding season. Rubbing of signpost structures allows deer to communicate via visual and chemical cues, which allows them to establish dominance hierarchies and maintain hierarchal status throughout the breeding season (Moore and Marchinton 1974, Miller et al. 1981, Hewitt 2011). Once a living tree is rubbed, the exposed light-colored sapwood creates a stark contrast in wooded areas, increasing visibility and further enticing deer to investigate the structure (Oehler et al. 1995). Anatomically, the tubular apocrine sudoriferous glands of white-tailed deer are located at the antler …


Nebline, January 2019 Jan 2019

Nebline, January 2019

NEBLINE Newsletter Archive from Nebraska Extension in Lancaster County

2018 Extension highlights

Benefit to people

Teaching, growing and making a difference

36,520 youth engaged in 4-H programs

Extension’s volunteers worth nearly $700,000

New Year, new you: Nutrition tips to a healthier you

RECIPE OF THE MONTH

Pesticide applicator 2019 training dates

Ag Estate and Succession Planning workshop, Jan. 23 & March 5

Successful Farmer Series

Upcoming green industry conferences

Extension’s 2019 Master Gardener trainings, two sites available

Garden Guide Things to Do This Month

Sticky situation: Using glue boards to monitor pests

HEART OF 4-H Volunteer Award: Susan Bulling

IT’S TIME TO RE-ENROLL IN 4-H!

Meet 2018–2019 4-H Council …


Nebraska Grazing Conference Proceedings, 2019, Center For Grassland Studies, University Of Nebraska-Lincoln Jan 2019

Nebraska Grazing Conference Proceedings, 2019, Center For Grassland Studies, University Of Nebraska-Lincoln

Nebraska Grazing Conference Proceedings

Rangeland Health Session

Managing Sand Deposits after the Flood by Daren Redfearn

Rangeland Health: What Is It and Why Do I Care?” by Patrick Shaver

Managing a Sandhills Ranch with an Eye to Soil Health by Dana Larsen

Grazinglands Management Session

Soil Health: Expectations and Evidence by Virginia Jin

Mob Grazing on Nebraska Sandhills Meadow by Walt Schacht

Effect of Length of Grazing Period on Upland Sandhills Range by Jerry Volesky

Carbon Input and Loss in Semi-arid Sandy Rangeland by Martha Mamo

Graze 365 by Jacob Miller

Soil Health and Grazing Strategies: Opportunities for Increasing Soil Water by Andrea Basche …


Microcontroller Based Granular Urea Application Attachment For Rice Transplanter, Md Towfiqur Rahman, Md Monjurul Alam, Md Mosharraf Hossain, Muhammad Rashed Al Mamun Jan 2019

Microcontroller Based Granular Urea Application Attachment For Rice Transplanter, Md Towfiqur Rahman, Md Monjurul Alam, Md Mosharraf Hossain, Muhammad Rashed Al Mamun

Department of Biological Systems Engineering: Papers and Publications

Transplanting and fertilizer application for rice production in Bangladesh are tedious, time consuming and laborious task, and mostly done manually. Mechanical transplanting of rice becoming popular in the country in recent years and few machines have been developed for granular urea deep placement, however, having some limitations. Placing granular urea precisely along with rice transplanting, an attempt was under taken to design and fabricate an electronic control granular urea applicator to be attach with a 4-row walk behind type rice transplanter. Fabrication of the electronic granular urea applicator was done in the workshop of the Department of Farm Power and …


Development Of Chlorophyll-Meter-Index-Based Dynamic Models For Evaluation Of High-Yield Japonica Rice Production In Yangtze River Reaches, Ke Zhang, Xiaojun Liu, Syed Tahir Ata-Ul-Karim, Songyang Li, Brian Krienke, Songyang Li, Qiang Cao, Yan Zhu, Weixing Cao, Yongchao Tian Jan 2019

Development Of Chlorophyll-Meter-Index-Based Dynamic Models For Evaluation Of High-Yield Japonica Rice Production In Yangtze River Reaches, Ke Zhang, Xiaojun Liu, Syed Tahir Ata-Ul-Karim, Songyang Li, Brian Krienke, Songyang Li, Qiang Cao, Yan Zhu, Weixing Cao, Yongchao Tian

Department of Agronomy and Horticulture: Faculty Publications

Accurate estimation of the nitrogen (N) spatial distribution of rice (Oryza sativa L.) is imperative when it is sought to maintain regional and global carbon balances. We systematically evaluated the normalized differences of the soil and plant analysis development (SPAD) index (the normalized difference SPAD indexes, NDSIs) between the upper (the first and second leaves from the top), and lower (the third and fourth leaves from the top) leaves of Japonica rice. Four multi-location, multi-N rate (0–390 kg ha-1) field experiments were conducted using seven Japonica rice cultivars (9915, 27123, Wuxiangjing14, Wunyunjing19, Wunyunjing24, Liangyou9, and Yongyou8). Growth …


Assessing Variation In Us Soybean Seed Composition (Protein And Oil), Yared Assefa, Larry C. Purcell, Montse Salmeron, Seth Naeve, Shaun N. Casteel, Peter Kovacs, Sotirios Archontoulis, Mark Licht, Fred Below, Herman Kandel, Laura E. Lindsey, John Gaska, Shawn Conley, Charles Shapiro, John M. Orlowski, Bobby R. Golden, Gurpreet Kaur, Maninderpal Singh, Kurt Thelen, Randall Laurenz, Dan Davidson, Igancio A. Ciampitti Jan 2019

Assessing Variation In Us Soybean Seed Composition (Protein And Oil), Yared Assefa, Larry C. Purcell, Montse Salmeron, Seth Naeve, Shaun N. Casteel, Peter Kovacs, Sotirios Archontoulis, Mark Licht, Fred Below, Herman Kandel, Laura E. Lindsey, John Gaska, Shawn Conley, Charles Shapiro, John M. Orlowski, Bobby R. Golden, Gurpreet Kaur, Maninderpal Singh, Kurt Thelen, Randall Laurenz, Dan Davidson, Igancio A. Ciampitti

Department of Agronomy and Horticulture: Faculty Publications

Soybean [Glycine max (L.) Merr.] seed composition and yield are a function of genetics (G), environment (E), and management (M) practices, but contribution of each factor to seed composition and yield are not well understood. The goal of this synthesis-analysis was to identify the main effects of G, E, and M factors on seed composition (protein and oil concentration) and yield. The entire dataset (13,574 data points) consisted of 21 studies conducted across the United States (US) between 2002 and 2017 with varying treatments and all reporting seed yield and composition. Environment (E), defined as site-year, was the dominant …


Engineering Linear, Branched-Chain Triterpene Metabolism In Monocots, Chase Kempinski, Zuodong Jiang, Garrett Zinck, Shirley J. Sato, Zhengxiang Ge, Thomas E. Clemente, Joseph Chappell Jan 2019

Engineering Linear, Branched-Chain Triterpene Metabolism In Monocots, Chase Kempinski, Zuodong Jiang, Garrett Zinck, Shirley J. Sato, Zhengxiang Ge, Thomas E. Clemente, Joseph Chappell

Department of Agronomy and Horticulture: Faculty Publications

Triterpenes are thirty-carbon compounds derived from the universal five-carbon prenyl precursors isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP). Normally, triterpenes are synthesized via the mevalonate (MVA) pathway operating in the cytoplasm of eukaryotes where DMAPP is condensed with two IPPs to yield farnesyl diphosphate (FPP), catalyzed by FPP synthase (FPS). Squalene synthase (SQS) condenses two molecules of FPP to generate the symmetrical product squalene, the first committed precursor to sterols and most other triterpenes. In the green algae Botryococcus braunii, two FPP molecules can also be condensed in an asymmetric manner yielding the more highly branched triterpene, botryococcene. Botryococcene …


Assessing The Value Of Grazed Corn Residue For Crop And Cattle Producers, Daren Redfearn, Jay Parsons, Mary Drewnoski, Marty Schmer, Rob Mitchell, James Macdonald, Jaymelynn Farney, Alexander Smart Jan 2019

Assessing The Value Of Grazed Corn Residue For Crop And Cattle Producers, Daren Redfearn, Jay Parsons, Mary Drewnoski, Marty Schmer, Rob Mitchell, James Macdonald, Jaymelynn Farney, Alexander Smart

Department of Agronomy and Horticulture: Faculty Publications

Integrated crop–livestock systems have included grazing perennial grasses during the spring and summer and corn (Zea mays L.) residues during the winter. Our objectives were to identify opportunities for expanded corn residue use through grazing and provide an economic assessment for value-added grazing. We estimated the economic value to the crop sector through grazing leased corn residue at over $95 million for Nebraska, South Dakota, Kansas, and North Dakota under current management. Additionally, gross economic value to the livestock sector in these states was estimated at greater than $191 million. Advantages for increased grazing use of corn residue include …


Response Surface Analysis Of Genomic Prediction Accuracy Values Using Quality Control Covariates In Soybean, Diego Jarquin, Reka Howard, George L. Graef, Aaron Lorenz Jan 2019

Response Surface Analysis Of Genomic Prediction Accuracy Values Using Quality Control Covariates In Soybean, Diego Jarquin, Reka Howard, George L. Graef, Aaron Lorenz

Department of Agronomy and Horticulture: Faculty Publications

An important and broadly used tool for selection purposes and to increase yield and genetic gain in plant breeding programs is genomic prediction (GP). Genomic prediction is a technique where molecular marker information and phenotypic data are used to predict the phenotype (eg, yield) of individuals for which only marker data are available. Higher prediction accuracy can be achieved not only by using efficient models but also by using quality molecular marker and phenotypic data. The steps of a typical quality control (QC) of marker data include the elimination of markers with certain level of minor allele frequency (MAF) and …


Winter Wheat Grain Yield Response To Fungicide Application Is Influenced By Cultivar And Rainfall, Emmanuel Byamukama, Shaukat Ali, Jonathan Kleinjan, Dalitso N. Yabwalo, Christopher Graham, Melanie Caffe-Treml, Nathan D. Mueller, John Rickertsen, William A. Berzonsky Jan 2019

Winter Wheat Grain Yield Response To Fungicide Application Is Influenced By Cultivar And Rainfall, Emmanuel Byamukama, Shaukat Ali, Jonathan Kleinjan, Dalitso N. Yabwalo, Christopher Graham, Melanie Caffe-Treml, Nathan D. Mueller, John Rickertsen, William A. Berzonsky

Department of Agronomy and Horticulture: Faculty Publications

Winter wheat is susceptible to several fungal pathogens throughout the growing season and foliar fungicide application is one of the strategies used in the management of fungal diseases in winter wheat. However, for fungicides to be profitable, weather conditions conducive to fungal disease development should be present. To determine if winter wheat yield response to fungicide application at the flowering growth stage (Feekes 10.5.1) was related to the growing season precipitation, grain yield from fungicide treated plots was compared to non-treated plots for 19 to 30 hard red winter wheat cultivars planted at 8 site years from 2011 through 2015. …


Climate-Smart Practices For Improvement Of Crop Yields In Mid-Hills Of Nepal, Roshan Subedi, Laxmi Dutt Bhatta, Erica Udas, Nand Kishor Agrawal, Keshab Datta Joshi, Dinesh Panday Jan 2019

Climate-Smart Practices For Improvement Of Crop Yields In Mid-Hills Of Nepal, Roshan Subedi, Laxmi Dutt Bhatta, Erica Udas, Nand Kishor Agrawal, Keshab Datta Joshi, Dinesh Panday

Department of Agronomy and Horticulture: Faculty Publications

Farming in Nepal mostly represents the hill farming system with the dominance of small-holder farmers. In recent days, farmers in the country are impacted by climate change. Events of surface runoff, landslides, and soil erosions, along with changes in rainfall pattern and intensity have elevated a decline in crop productivity and soil fertility. Considering the situation, a pilot project on Resilient Mountain Village was implemented in Kavrepalanchowk district of Nepal from 2014–2016 with a participatory approach to demonstrate climate-smart practices. These practices include the application of locally prepared bio-fertilizer (named as “jholmal”), green manuring in rice (Oryza sativa L.) …


Generating High Density, Low Cost Genotype Data In Soybean [Glycine Max (L.) Merr.], Mary M. Happ, Haichuan Wang, George L. Graef, David L. Hyten Jan 2019

Generating High Density, Low Cost Genotype Data In Soybean [Glycine Max (L.) Merr.], Mary M. Happ, Haichuan Wang, George L. Graef, David L. Hyten

Department of Agronomy and Horticulture: Faculty Publications

Obtaining genome-wide genotype information for millions of SNPs in soybean [Glycine max (L.) Merr.] often involves completely resequencing a line at 5X or greater coverage. Currently, hundreds of soybean lines have been resequenced at high depth levels with their data deposited in the NCBI Short Read Archive. This publicly available dataset may be leveraged as an imputation reference panel in combination with skim (low coverage) sequencing of new soybean genotypes to economically obtain high-density SNP information. Ninety-nine soybean lines resequenced at an average of 17.1X were used to generate a reference panel, with over 10 million SNPs called using …


A Tmeff2-Regulated Cell Cycle Derived Gene Signature Is Prognostic Of Recurrence Risk In Prostate Cancer, Constantin Georgescu, Joshua M. Corbin, Sandra Thibivilliers, Zachary D. Webb, Yan D. Zhao, Jan Koster, Kar-Ming Fung, Adam S. Asch, Jonathan D. Wren, Maria J. Ruiz-Echevarria Jan 2019

A Tmeff2-Regulated Cell Cycle Derived Gene Signature Is Prognostic Of Recurrence Risk In Prostate Cancer, Constantin Georgescu, Joshua M. Corbin, Sandra Thibivilliers, Zachary D. Webb, Yan D. Zhao, Jan Koster, Kar-Ming Fung, Adam S. Asch, Jonathan D. Wren, Maria J. Ruiz-Echevarria

Department of Agronomy and Horticulture: Faculty Publications

Background: The clinical behavior of prostate cancer (PCa) is variable, and while the majority of cases remain indolent, 10% of patients progress to deadly forms of the disease. Current clinical predictors used at the time of diagnosis have limitations to accurately establish progression risk. Here we describe the development of a tumor suppressor regulated, cell-cycle gene expression based prognostic signature for PCa, and validate its independent contribution to risk stratification in several radical prostatectomy (RP) patient cohorts.

Methods: We used RNA interference experiments in PCa cell lines to identify a gene expression based gene signature associated with Tmeff2, an …


Impact Of Hurricane Katrina On The Coastal Systems Of Southern Louisiana, Wen-Ching Chuang, Tarsha Eason, Ahjond Garmestani, Caleb Roberts Jan 2019

Impact Of Hurricane Katrina On The Coastal Systems Of Southern Louisiana, Wen-Ching Chuang, Tarsha Eason, Ahjond Garmestani, Caleb Roberts

Department of Agronomy and Horticulture: Faculty Publications

Natural disasters, such as hurricanes and forest fires, could trigger collapse and reorganization of social-ecological systems. In the face of external perturbations, a resilient system would have capacity to absorb impacts, adapt to change, learn, and if needed, reorganize within the same regime. Within this context, we asked how human and natural systems in Louisiana responded to Hurricane Katrina, and how the natural disaster altered the status of these systems. This paper discusses community resilience to natural hazards and addresses the limitations for assessing disaster resilience. Furthermore, we assessed social and environmental change in New Orleans and southern Louisiana through …


Expression Of The Arabidopsis Wrinkled 1 Transcription Factor Leads To Higher Accumulation Of Palmitate In Soybean Seed, Pamela A. Vogel, Shen Bayon De Noyer, Hyunwoo Park, Hanh Nguyen, Lili Hou, Taity Changa, Hoang Le Khang, Ozan N. Ciftci, Tong Wang, Edgar B. Cahoon, Thomas Elmo Clemente Jan 2019

Expression Of The Arabidopsis Wrinkled 1 Transcription Factor Leads To Higher Accumulation Of Palmitate In Soybean Seed, Pamela A. Vogel, Shen Bayon De Noyer, Hyunwoo Park, Hanh Nguyen, Lili Hou, Taity Changa, Hoang Le Khang, Ozan N. Ciftci, Tong Wang, Edgar B. Cahoon, Thomas Elmo Clemente

Department of Agronomy and Horticulture: Faculty Publications

Soybean (Glycine max [L.] Merr.) is a commodity crop highly valued for its protein and oil content. The high percentage of polyunsaturated fatty acids in soybean oil results in low oxidative stability, which is a key parameter for usage in baking, high temperature frying applications, and affects shelf life of packaged products containing soybean oil. Introduction of a seed-specific expression cassette carrying the Arabidopsis transcription factor WRINKLED1 (AtWRI1) into soybean, led to seed oil with levels of palmitate up to approximately 20%. Stacking of the AtWRI1 transgenic allele with a transgenic locus harbouring the mangosteen steroyl-ACP thioesterase (GmFatA) resulted …


Applicability Of The Dual Isotopes Δ15n And Δ18o To Identify Nitrate In Groundwater Beneath Irrigated Cropland, R. F. Spalding, A. J. Hirsh, M. E. Exner, N. A. Little, K. L. Kloppenborg Jan 2019

Applicability Of The Dual Isotopes Δ15n And Δ18o To Identify Nitrate In Groundwater Beneath Irrigated Cropland, R. F. Spalding, A. J. Hirsh, M. E. Exner, N. A. Little, K. L. Kloppenborg

Department of Agronomy and Horticulture: Faculty Publications

Identification of the nitrate sources that adversely impact groundwater quality is a necessary first step in the control of this major worldwide pollutant. The impact of nitrate leachate from urea-ammonium nitrate (UAN) (50% urea-N, 25% ammonium-N, 25% nitrate-N) fertilizer, whose use has increased dramatically in the last three decades largely because it can be applied through sprinkler irrigation systems to corn in all growth stages, is investigated. The dual isotopes δ15NNO3 and δ18ONO3 were measured in groundwater samples from 39 irrigation wells in two intensively sprinkler-irrigated, corn-growing areas of Nebraska with nitrate-contaminated (N …


Statistical And Machine Learning Methods Evaluated For Incorporating Soil And Weather Into Corn Nitrogen Recommendations, Curtis J. Ransom, Newell R. Kitchen, James J. Camberato, Paul R. Carter, Richard B. Ferguson, Fabian G. Fernandez, David W. Franzen, Carrie A. M. Laboski, D. Brenton Myers, Emerson D. Nafziger, John E. Sawyer, John F. Shanahan Jan 2019

Statistical And Machine Learning Methods Evaluated For Incorporating Soil And Weather Into Corn Nitrogen Recommendations, Curtis J. Ransom, Newell R. Kitchen, James J. Camberato, Paul R. Carter, Richard B. Ferguson, Fabian G. Fernandez, David W. Franzen, Carrie A. M. Laboski, D. Brenton Myers, Emerson D. Nafziger, John E. Sawyer, John F. Shanahan

Department of Agronomy and Horticulture: Faculty Publications

Nitrogen (N) fertilizer recommendation tools could be improved for estimating corn (Zea mays L.) N needs by incorporating site-specific soil and weather information. However, an evaluation of analytical methods is needed to determine the success of incorporating this information. The objectives of this research were to evaluate statistical and machine learning (ML) algorithms for utilizing soil and weather information for improving corn N recommendation tools. Eight algorithms [stepwise, ridge regression, least absolute shrinkage and selection operator (Lasso), elastic net regression, principal component regression (PCR), partial least squares regression (PLSR), decision tree, and random forest] were evaluated using a dataset …


Identification Of Quantitative Trait Loci For Plant Height, Crown Diameter, And Plant Biomass In A Pseudo-F2 Population Of Switchgrass, Megan Taylor, Carl-Erik Tornqvist, Xiongwei Zhao, R. W. Doerge, Michael D. Casler, Yiwei Jiang Jan 2019

Identification Of Quantitative Trait Loci For Plant Height, Crown Diameter, And Plant Biomass In A Pseudo-F2 Population Of Switchgrass, Megan Taylor, Carl-Erik Tornqvist, Xiongwei Zhao, R. W. Doerge, Michael D. Casler, Yiwei Jiang

Department of Agronomy and Horticulture: Faculty Publications

Switchgrass (Panicum virgatum) is a perennial warm-season grass that produces high biomass yield. Identification of mechanisms for genetic regulation of biomass traits has potential to facilitate genetic manipulation of switchgrass for enhancing biomass yield. The objective of this study was to identify quantitative trait loci for biomass-related traits in a pseudo-F2 population of switchgrass derived from an upland cross with a lowland switchgrass cultivar. Plant height (HT), crown diameter (CD), and plant biomass (PB) were assessed in field studies in 2015 and 2016. Plant height was positively correlated with PB in both years but only correlated with …


Utilizing Trait Networks And Structural Equation Models As Tools To Interpret Multi‑Trait Genome‑Wide Association Studies, Mehdi Momen, Malachy T. Campbell, Harkamal Walia, Gota Morota Jan 2019

Utilizing Trait Networks And Structural Equation Models As Tools To Interpret Multi‑Trait Genome‑Wide Association Studies, Mehdi Momen, Malachy T. Campbell, Harkamal Walia, Gota Morota

Department of Agronomy and Horticulture: Faculty Publications

Background: Plant breeders seek to develop cultivars with maximal agronomic value, which is often assessed using numerous, often genetically correlated traits. As intervention on one trait will affect the value of another, breeding decisions should consider the relationships among traits in the context of putative causal structures (i.e., trait networks). While multi-trait genome-wide association studies (MTM-GWAS) can infer putative genetic signals at the multivariate scale, standard MTM-GWAS does not accommodate the network structure of phenotypes, and therefore does not address how the traits are interrelated. We extended the scope of MTM-GWAS by incorporating trait network structures into GWAS using structural …


A Two-Amino Acid Difference In The Coat Protein Of Satellite Panicum Mosaic Virus Isolates Is Responsible For Differential Synergistic Interactions With Panicum Mosaic Virus, R. V. Chowda-Reddy, Nathan A. Palmer, Serge Edme, Gautam Sarath, Frank A. Kovacs, Gary Y. Yuen, Robert Mitchell, Satyanarayana Tatineni Jan 2019

A Two-Amino Acid Difference In The Coat Protein Of Satellite Panicum Mosaic Virus Isolates Is Responsible For Differential Synergistic Interactions With Panicum Mosaic Virus, R. V. Chowda-Reddy, Nathan A. Palmer, Serge Edme, Gautam Sarath, Frank A. Kovacs, Gary Y. Yuen, Robert Mitchell, Satyanarayana Tatineni

Department of Agronomy and Horticulture: Faculty Publications

Panicum mosaic virus (PMV) (genus Panicovirus, family Tombusviridae) and its molecular parasite, Satellite panicum mosaic virus (SPMV), synergistically interact in coinfected proso and pearl millet (Panicum miliaceum L.) plants resulting in a severe symptom phenotype. In this study, we examined synergistic interactions between the isolates of PMV and SPMV by using PMV-NE, PMV85, SPMV-KS, and SPMV-Type as interacting partner viruses in different combinations. Coinfection of proso millet plants by PMV-NE and SPMV-KS elicited severe mosaic, chlorosis, stunting, and eventual plant death compared with moderate mosaic, chlorotic streaks, and stunting by PMV85 and SPMV-Type. In reciprocal combinations, coinfection …


Evaluation Of Spray Pattern Uniformity Using Three Unique Analyses As Impacted By Nozzle, Pressure, And Pulse-Widthmodulation Duty Cycle, Thomas R. Butts, Joe D. Luck, Bradley K. Fritz, W. Clint Hoffmann, Greg R. Kruger Jan 2019

Evaluation Of Spray Pattern Uniformity Using Three Unique Analyses As Impacted By Nozzle, Pressure, And Pulse-Widthmodulation Duty Cycle, Thomas R. Butts, Joe D. Luck, Bradley K. Fritz, W. Clint Hoffmann, Greg R. Kruger

Department of Agronomy and Horticulture: Faculty Publications

BACKGROUND: The increasing popularity of pulse-width modulation (PWM) sprayers requires that application interaction effects on spray pattern uniformity be completely understood to maintain a uniform overlap of spray, thereby reducing crop injury potential andmaximizing coverage on target pests. The objective of this researchwas to determine the impacts of nozzle type (venturi vs. non-venturi), boom pressure, and PWMduty cycle on spray pattern uniformity. Research was conducted using an indoor spray patternator located at the University of Nebraska-Lincoln in Lincoln, NE, USA. Coefficient of variation (CV), root mean square error (RMSE), and average percent error (APE) were used to characterize spray pattern …


Benchmarking Irrigation Water Use In Producer Fields In The Us Central Great Plains, Katherine E. B. Gibson, Justin E. Gibson, Patricio Grassini Jan 2019

Benchmarking Irrigation Water Use In Producer Fields In The Us Central Great Plains, Katherine E. B. Gibson, Justin E. Gibson, Patricio Grassini

Department of Agronomy and Horticulture: Faculty Publications

Efficient use of freshwater resources is necessary to balance food production and long-term sustainability of irrigated agricultural systems. Here we developed a framework to benchmark irrigation water use relative to crop yield for individual fields based on site-specific weather and soil. Subsequently, we used the framework to diagnose on-farm irrigation management, in relation to crop production, in maize and soybean producer fields in Nebraska (USA).We found actual irrigation to be similar to estimated irrigation water requirement in about half of the fields (i.e. small water surplus). Remarkably, these fields attained yields similar to fields where actual irrigation exceeded water requirements …


Comparing Infiltration Rates In Soils Managed With Conventional And Alternative Farming Methods: A Meta-Analysis, Andrea D. Basche, Marcia S. Delonge Jan 2019

Comparing Infiltration Rates In Soils Managed With Conventional And Alternative Farming Methods: A Meta-Analysis, Andrea D. Basche, Marcia S. Delonge

Department of Agronomy and Horticulture: Faculty Publications

Identifying agricultural practices that enhance water cycling is critical, particularly with increased rainfall variability and greater risks of droughts and floods. Soil infiltration rates offer useful insights to water cycling in farming systems because they affect both yields (through soil water availability) and other ecosystem outcomes (such as pollution and flooding from runoff). For example, conventional agricultural practices that leave soils bare and vulnerable to degradation are believed to limit the capacity of soils to quickly absorb and retain water needed for crop growth. Further, it is widely assumed that farming methods such as no-till and cover crops can improve …


Spatial Imaging And Screening For Regime Shifts, Daniel R. Uden, Dirac Twidwell, Craig R. Allen, Matthew O. Jones, David E. Naugle, Jeremy D. Maestas, Brady W. Allred Jan 2019

Spatial Imaging And Screening For Regime Shifts, Daniel R. Uden, Dirac Twidwell, Craig R. Allen, Matthew O. Jones, David E. Naugle, Jeremy D. Maestas, Brady W. Allred

Department of Agronomy and Horticulture: Faculty Publications

Screening is a strategy for detecting undesirable change prior to manifestation of symptoms or adverse effects. Although the well-recognized utility of screening makes it commonplace in medicine, it has yet to be implemented in ecosystem management. Ecosystem management is in an era of diagnosis and treatment of undesirable change, and as a result, remains more reactive than proactive and unable to effectively deal with today’s plethora of non-stationary conditions. In this paper, we introduce spatial imaging-based screening to ecology. We link advancements in spatial resilience theory, data, and technological and computational capabilities and power to detect regime shifts (i.e., vegetation …