Life Sciences Commons^™

Adding Value To Crop Production Systems By Integrating Forage Cover Crop Grazing, Robert B. Mitchell, Daren D. Redfearn, Kenneth P. Vogel, Terry J. Klopfenstein, Galen Erickson, P. Steven Baenziger, Bruce E. Anderson, Mary E. Drewnoski, Jay Parsons, Steven D. Masterson, Marty R. Schmer, Virginia L. Jin

Department of Agronomy and Horticulture: Faculty Publications

In addition to their value as cereal grains, wheat (Triticum aestivum L.) and triticale (× Triticosecale Wittmack) are important cool-season annual forages and cover crops. Yearling steer (Bos taurus) performance was compared in the spring following autumn establishment as for age cover crops after soybean [Glycine max (L.) Merr.] grain harvest. Replicated pastures (0.4 ha) were no-till seeded in three consecutive years into soybean stubble in autumn, fertilized, and grazed the following spring near Ithaca, Nebraska, USA. Each pasture (n = 3) was continuously stocked in spring with four yearling steers (380 ± 38 kg) for …

Evaluation Of Weed Control Efficacy And Crop Tolerance To Florpyrauxifen-Benzyl Coated Onto Urea, Bodie Lyn Cotter

Graduate Theses and Dissertations

Frequent off-target movement occurrences to soybean [Glycine max (L.) Merr.], rice (Oryza sativa L.) injury, and a lack of barnyardgrass [Echinochloa crus-galli (L.) P. Beauv.] control followed the commercial launch of florpyrauxifen-benzyl in 2018. Florpyrauxifen-benzyl is a synthetic auxin, Herbicide Resistance Action Committee (HRAC)/Weed Science Society of America (WSSA) Group 4 herbicide used for postemergence weed control in rice and labeled for application at 30 g ae ha-1. Previous research documented that soybean was susceptible to injury following spray applications of florpyrauxifen-benzyl at less-than-labeled rates, and certain varieties of rice are less tolerant to spray-applied florpyrauxifen-benzyl at 30 g ae …

Method Developments To Identify Loci And Selection Patterns Associated With Genotype By Environment Interactions In Soybean, Mary M. Happ

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

For many complex traits such as grain yield, genotype by environment (GxE) interactions are a prevalent source of phenotypic variation. Exploring the capacity of different methodologies to help describe and quantify the GxE interaction landscape for grain yield is an important step in informing plant breeders what the most viable strategies for management and exploitation of GxE may be. In this endeavor, we compared the results from multiple genome wide association studies (GWAS) that used either stability estimators as a phenotype to capture GxE variance, or directly mapped GxE in a mixed model for yield. Leading into this study, a …

Arkansas Soybean Performance Tests 2022, J. F. Carlin, R. B. Mulloy, R. D. Bond

Arkansas Agricultural Experiment Station Research Series

Soybean variety and strain performance tests are conducted each year in Arkansas by the University of Arkansas System Division of Agriculture’s Arkansas Crop Variety Improvement Program. The tests provide information to companies developing varieties and/ or marketing seed within the state, and aid the Arkansas Cooperative Extension Service in formulating variety recommendations for soybean producers.

Genomic Selection For Yield And Seed Composition Stability In An Applied Soybean Breeding Program, Benjamin Harms

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

Stability traits are of primary importance in plant breeding to ensure consistency in phenotype across a range of environments. However, selection efficiency and accuracy for stability traits can be hindered due to the requirement of obtaining phenotype data across multiple years and environments for proper stability analysis. Genomic selection is a method that allows prediction of a phenotype prior to observation in the field using genome-wide marker data and phenotype data from a training population. To assess prediction of stability traits, two elite-yielding soybean populations developed three years apart in the same breeding program were used. The individuals in each …

A Leaf-Level Spectral Library To Support High-Throughput Plant Phenotyping: Predictive Accuracy And Model Transfer, Nuwan K. Wijewardane, Huichun Zhang, Jinliang Yang, James C. Schnable, Daniel P. Schachtman, Yufeng Ge

Department of Agronomy and Horticulture: Faculty Publications

Leaf-level hyperspectral reflectance has become an effective tool for high-throughput phenotyping of plant leaf traits due to its rapid, low-cost, multi-sensing, and non-destructive nature. However, collecting samples for model calibration can still be expensive, and models show poor transferability among different datasets. This study had three specific objectives: first, to assemble a large library of leaf hyperspectral data (n=2460) from maize and sorghum; second, to evaluate two machine-learning approaches to estimate nine leaf properties (chlorophyll, thickness, water content, nitrogen, phosphorus, potassium, calcium, magnesium, and sulfur); and third, to investigate the usefulness of this spectral library for predicting external datasets …

Drought Susceptibility Index; A Preferred Criterion In Screening For Tolerance In Soybean, Muhammad Zeshan Zafer, Muhammad Hammad Nadeem Tahir, Muhammad Amir Bakhtavar, Essam Darwish, Mahmood Alam Khan, Zulqurnain Khan, Chahat Fatima, Ayesha Aftab, Shifa Ur Rahman, Shoaib Ur Rehman

Journal of Bioresource Management

Soybean (Glycine max L.) yield and yield related traits are constrained by drought. Adaptation of soybean to changing environment could be improved by exploitation and introgression of diverse germplasm in breeding program. In present study, the response to drought conditions, especially at flowering stage, was evaluated to determine the potential soybean germplasm for future soybean breeding programs in Pakistan. Field experiment was conducted under two water regimes i.e. well-water and water-limited, to assess the effect of drought in seed yield and yield related traits. Although, drought led to overall reduction of ~15 % in thousand seed weight but still …

Recombination Hotspots In Soybean [Glycine Max (L.) Merr.], Samantha Mcconaughy, Keenan L. Amundsen, Qijian Song, Vince Pantalone, D. Hyten

Department of Agronomy and Horticulture: Faculty Publications

Recombination allows for the exchange of genetic material between two parents, which plant breeders exploit to make improved cultivars. This recombination is not distributed evenly across the chromosome. Recombination mostly occurs in euchromatic regions of the genome and even then, recombination is focused into clusters of crossovers termed recombination hotspots. Understanding the distribution of these hotspots along with the sequence motifs associated with them may lead to methods that enable breeders to better exploit recombination in breeding. To map recombination hotspots and identify sequence motifs associated with hotspots in soybean [Glycine max (L.) Merr.], two biparental recombinant inbred lines …

Effect Od Different Sources And Application Rates Of Sulfur On Corn And Soybean Production Systems In Louisiana, Diego Mayorga Valladares

LSU Master's Theses

Sulfur (S) is a structural component of amino acids such as cysteine and methionine and is involved in important functions within the plant like photosynthesis, carbon and nitrogen metabolism, protein synthesis of oils, and detoxification mechanisms. Sulfur deficiency in crops has intensified around the world. Some of the reasons are improvement in controlling SO₂ emissions from industries, growing usage of high analysis S-free fertilizers and augmented cropping intensity. Sulfur fertilization has become an important factor in crop production systems and fertilization guidelines for S need to be up-to-date to improve use efficiency and compensate for rising prices of fertilizers. …

Breeding Soybean [Glycine Max (L) Merr.] Under Reduced Irrigation, Francia Seconde Ravelombola

Graduate Theses and Dissertations

Soybean [Glycine max (L) Merr.], a legume species native to East Asia in the Fabaceae family, ranks among the most important food crops in the world. It is widely grown and known for its high protein and oil concentration. Soybean is valuable because its seeds have multiple applications in food, feed, pharmaceutical, and industrial enterprises. Even though seed yield is the most important trait, breeders have recently given a significant attention to quality traits, such as high protein or modified oil concentration. Soybean seed protein inheritance has been extensively studied; however, genetics of high-protein ‘BARC-7’ soybean are still unknown.On the …

Re-Evaluation Of Late Season Action Thresholds And The Effect Of Seed Treatments On Early Season Colonization Of Threecornered Alfalfa Hopper, Spissistilus Festinus (Say), In Louisiana Soybean, Glycine Max (L) Merr, Tyler Ray Tagle Musgrove

LSU Master's Theses

Soybean, Glycine max (L.) Merr, is considered the most economically important oil and feed crop in the US and is grown on nearly 35,000,000 ha on an annual basis. Factors that limit yield include weed pressure, disease infection, and of particular interest to entomologists, insect herbivory. Soybean is targeted by a range of above and below ground pests which are primarily controlled by insecticides. Neonicotinoids are a recently popularized insecticide class that when applied as a seed treatment, can provide protection from early season pests. The most economically significant early season pest is threecornered alfalfa hopper, Spissistilus festinus (Say), whose …

Fine Mapping And Cloning Of The Major Seed Protein Quantitative Trait Loci On Soybean Chromosome 20, Christina E. Fliege, Russell A. Ward, Pamela Vogel, Hanh Nguyen, Truyen Quach, Ming Guo, João Paulo Gomes Viana, Lucas Borges Dos Santos, James Specht, Thomas Clemente, Matthew E. Hudson, Brian W. Diers

Department of Agronomy and Horticulture: Faculty Publications

Soybean [Glycine max (L.) Merr.] is a unique crop species because it has high levels of both protein and oil in its seed. Of the many quantitative trait loci (QTL) controlling soybean seed protein content, alleles of the cqSeed protein-003 QTL on chromosome 20 exert the greatest additive effect. The high-protein allele exists in both cultivated and wild soybean (Glycine soja Siebold & Zucc.) germplasm. Our objective was to fine map this QTL to enable positional-based cloning of its underlying causative gene(s). Fine mapping was achieved by developing and testing a series of populations in which the chromosomal region surrounding …

Field Validation Of A Farmer Supplied Data Approach To Close Soybean Yield Gaps In The Us North Central Region, José F. Andrade, Spyridon Mourtzinis, Juan I. Rattalino Edreira, Shawn P. Conley, John Gaska, Herman J. Kandel, Laura E. Lindsey, Seth Naeve, Scott Nelson, Maninder P. Singhi, Laura J. Thompson, James E. Specht, Patricio Grassini

Department of Agronomy and Horticulture: Faculty Publications

CONTEXT: Producer-reported data can be used to identify suites of management practices that lead to higher yield and profit. However, a rigorous validation of the approach in relation to its potential impact on farmer yield and profit is lacking.

OBJECTIVE: This study aimed to validate a producer-data approach on its capability to guide on-farm evaluation of management practices with greatest potential for increasing producer yield and profit. We show proof of concept using soybean in the North Central US region as a case study.

METHODS: We used a combination of regression tree analysis and a spatial framework to determine practices …

Influence Of Planting Date, Maturity Group, Harvest Aids And Fungicide Application On Soybean (Glycine Max (L.) Seed Quality, Ana Priscila Campos

LSU Master's Theses

Field studies evaluated the influence of planting date, maturity group, and harvest timing on soybean yield and seed quality at the LSU AgCenter Northeast (NERS), Macon Ridge, and Dean Lee Research Stations in 2018-2020. In addition, the influence of harvest aid and fungicide application on seed quality impact from delayed harvest and environment was investigated at NERS in 2019 and 2020 in both field and environmentally controlled growth chambers. Soybean yield was maximized when maturity group IV and V soybean varieties were planted between Mid-April and Mid-May. Earlier and later planting dates did not result in maximized yield. Planting date …

Rhizosphere Microbiomes In A Historical Maize-Soybean Rotation System Respond To Host Species And Nitrogen Fertilization At The Genus And Subgenus Levels, Michael A. Meier, Martha G. Lopez-Guerrero, Ming Guo, Marty Schmer, Josh Herr, James Schnable, James R. Alfano, Jinliang Yang

Department of Agronomy and Horticulture: Faculty Publications

Root-associated microbes are key players in plant health, disease resistance, and nitrogen (N) use efficiency. It remains largely unclear how the interplay of biological and environmental factors affects rhizobiome dynamics in agricultural systems. In this study, we quantified the composition of rhizosphere and bulk soil microbial communities associated with maize (Zea mays L.) and soybean (Glycine max L.) in a long-term crop rotation study under conventional fertilization and low-N regimes. Over two growing seasons, we evaluated the effects of environmental conditions and several treatment factors on the abundance of rhizosphere- and soil-colonizing microbial taxa. Time of sampling, host plant species, …

Screening And Breeding Soybean For Flood Tolerance, Maria Roberta De Oliveira

Graduate Theses and Dissertations

Waterlogging can be detrimental to soybean [Glycine max (L.) Merr.] growth and development, with effects ranging from chlorosis and stunting to yield loss and plant death. Soybean responses to, and the effects of, waterlogging are dependent on the growth stage of the plant at the initiation of waterlogging. The objectives of this study were: (1) to assess the effectiveness of Genomic Selection (GS), Marker Assisted Selection (MAS) and Phenotypic Selection for flood tolerance at the progeny row stage as compared to random selection, for the development of high-yielding flood-tolerant lines; and (2) to compare field-screening and hydroponic greenhouse screening methodologies …

Identifying Drought Tolerance Traits In Tennessee Soybean Genotypes: Recovery From Severe Water Deficit Stress, Samuel W. Purdom

Masters Theses

Ninety-four percent of U.S. grown soybeans are produced under rainfed conditions with intermittent droughts occurring late in the season during reproductive growth stages. Due to the temporary nature of drought, the ability of a crop to survive and recover effectively from water deficit stress is important for ensuring yield stability. In 2019 and 2020, two greenhouse experiments and two field studies were conducted to screen eleven soybean genotypes for transpiration response and recovery from water deficit stress and high vapor pressure deficit (VPD). In the first greenhouse study, soybean plants were grown in pots sealed to prevent evaporation and plants …

Comparing A Mixed Model Approach To Traditional Stability Estimators For Mapping Genotype By Environment Interactions And Yield Stability In Soybean [Glycine Max (L.) Merr.], Mary M. Happ, George L. Graef, Haichuan Wang, Reka Howard, Luis Posadas, David L. Hyten

Department of Agronomy and Horticulture: Faculty Publications

Identifying genetic loci associated with yield stability has helped plant breeders and geneticists begin to understand the role and influence of genotype by environment (GxE) interactions in soybean [Glycine max (L.) Merr.] productivity, as well as other crops. Quantifying a genotype’s range of performance across testing locations has been developed over decades with dozens of methodologies available. This includes directly modeling GxE interactions as part of an overall model for yield, as well as methods which generate overall yield “stability” values from multi-environment trial data. Correspondence between these methods as it pertains to the outcomes of genome wide association studies …

A Bumper Crop Of Snps In Soybean Through High-Density Genotyping-By-Sequencing (Hd-Gbs), Davoud Torkamaneh, Jerome Laroche, Brian Boyle, David L. Hyten, Fancois Belzile

Department of Agronomy and Horticulture: Faculty Publications

No abstract provided.

The Role Of The Auxin Biosynthesis And Signaling In Soybean Root Nodule Development, Mucahid Bozkus

Electronic Theses and Dissertations

Nitrogen(N) is one of the most important plant nutrients for plant growth and yield, however, its abundance in the soil is not sufficient for profitable crop production. The use of chemical fertilizers helps address soil N deficiency in agriculture. However, due to the environmental pollution resulting from excessive use of fertilizers, alternative forms of N for agriculture are a necessity. Leguminous plants such as soybean (Glycine max) form a symbiotic association with N-fixing rhizobia to meet their N demands. Legume-rhizobia symbiosis results in the formation of unique structures called nodules where rhizobia convert atmospheric nitrogen into plant usable forms, thus …

Development Of Mping-Based Activation Tags For Crop Insertional Mutagenesis, Alexander Johnson, Edward Mcassey, Stephanie Diaz, Jacod Reagin, Priscilla S. Redd, Daymond R. Parrilla, Hanh Nguyen, Adrian Stec, Lauren A.L. Mcdaniel, Thomas E. Clemente, Robert M. Stupar, Wayne A. Parrott, C. Nathan Hancock

Department of Agronomy and Horticulture: Faculty Publications

Modern plant breeding increasingly relies on genomic information to guide crop im- provement. Although some genes are characterized, additional tools are needed to effectively identify and characterize genes associated with crop traits. To address this need, the mPing element from rice was modified to serve as an activation tag to in- duce expression of nearby genes. Embedding promoter sequences in mPing resulted in a decrease in overall transposition rate; however, this effect was negated by using a hyperactive version of mPing called mmPing20. Transgenic soybean events carrying mPing-based activation tags and the appropriate transposase expression cassettes showed evidence of transposition. …

Crop Response To Low-Dose Dicamba, Mason Castner

Graduate Theses and Dissertations

The introduction of dicamba-resistant (DR) soybean [Glycine max (L.) Merr.] and cotton (Gossypium hirsutum L.) followed by a label allowing over-the-top applications of dicamba in the 2017 provided growers an additional option for broadleaf weed control. Because non-DR soybean is sensitive to low concentrations of dicamba, postemergence dicamba applications present growers choosing to plant non-DR soybean with concerns of damage from off-target movement through physical drift and volatilization of the herbicide as well as tank-contamination from prior dicamba application. Consequences of low-dose dicamba exposure on sensitive vegetative and reproductive soybean have been well researched, but little is known regarding the …

Development Of Mping-Based Activation Tags For Crop Insertional Mutagenesis, Alexander Johnson, Edward Mcassey, Stephanie Diaz, Jacob Reagin, Priscilla S. Redd, Daymond R. Parrilla, Hanh T. Nguyen, Adrian Stec, Lauren A.L. Mcdaniel, Thomas E. Clemente, Robert M. Stupar, Wayne A. Parrott, C Nathan Hancock

Department of Agronomy and Horticulture: Faculty Publications

Modern plant breeding increasingly relies on genomic information to guide crop improvement. Although some genes are characterized, additional tools are needed to effectively identify and characterize genes associated with crop traits. To address this need, the mPing element from rice was modified to serve as an activation tag to induce expression of nearby genes. Embedding promoter sequences in mPing resulted in a decrease in overall transposition rate; however, this effect was negated by using a hyperactive version of mPing called mmPing20. Transgenic soybean events carrying mPing-based activation tags and the appropriate transposase expression cassettes showed evidence of transposition. Expression analysis …

Association Mapping For Soybean (Glycine Max L. Merr.) Protein And Oil Content, Joseph Najjar

Graduate Theses and Dissertations

Soybean [Glycine Max (L.) Merrill] is an important economic crop because of its high content of seed protein and oil. Seed oil and protein content are quantitative inherited traits. The genetics of seed protein and oil levels have been extensively studied, with 367 QTL reported for protein and 475 QTL reported for oil to date. Validation of such QTLs, and identification of easily-automatable molecular markers around these QTL will aid the progression of breeding for such traits. The focus of this research was to discover novel and verify previously reported QTL related to protein and/or oil content via Genome-Wide Association …

Sensitivity Of Enlisttm And Roundup Ready Xtend® Technologies To Auxin Herbicides And Comparison Of Resistance To Susceptible Cotton And Soybean Cultivars, James Rose

Graduate Theses and Dissertations

Increases in weed resistance have led to the development of new herbicide-resistant crop technologies, namely the Roundup Ready Xtend® and EnlistTM weed control systems. These new technologies provide resistance to applications of the synthetic auxins dicamba or 2,4-D, respectively, in traited cotton or soybean. It is unknown if there is any resistance to other herbicides within the synthetic auxin group (WSSA Group 4) in these traited crops. Experiments were conducted with auxin herbicides representing all five families within WSSA Group 4. Herbicides were applied either preemergence (PRE) or postemergence (POST) relative to the crop in a single application. Applications were …

Developing A High-Throughput Method To Screen Soybean Germplasm For Hypoxia Tolerance In Hydroponic Systems, Derrick Harrison

Graduate Theses and Dissertations

Soybean [Glycine max (Merr.)], the second most planted crop in the United States, is sensitive to field flooding due to depletion of oxygen and accumulation of CO2 in the rhizosphere. There is a need to breed cultivars that are adapted to areas prone to flooding, but field evaluations in the U.S. are limited because of time (one generation per year) and availability of resources (impermeable soils, irrigation, equipment to build levees). The purpose of this study was to develop and execute a protocol of germplasm screening for hypoxia tolerance using hydroponics in a controlled greenhouse environment. Germination rates and vigor …

Cover Cropping In Soybean-Corn Rotation System: Economic, Agronomic, And Soil Fertility Impact, Jose Rodolfo Mite

LSU Doctoral Dissertations

Planting winter-annual cover crops prevent soil erosion, reduces water runoff, and improves soil structure and soil quality. This research was conducted from 2017 to 2019 to evaluate the nutrient turnover of different species of cover crops in soils under different row crop production systems in Northeast and Central Louisiana. In Northeast Louisiana (Site 1, 2, and 3), treatments (cover crops and no cover crop) were arranged in a strip trial with three replications. At the Ben Hur Research Station, the treatments included three planting dates (September, October, and November) with [7 kg ha^-1 of phosphorus (P) and potassium (K)] …

Assessing Approaches For Stratifying Producer Fields Based On Biophysical Attributes For Regional Yield-Gap Analysis, Spyridon Mourtzinis, Patricio Grassini, Juan I. Rattalino Edreira, José F. Andrade, Peter M. Kyveryga, Shawn P. Conley

Department of Agronomy and Horticulture: Faculty Publications

Large databases containing producer field-level yield and management records can be used to identify causes of yield gaps. A relevant question is how to account for the diverse biophysical background (i.e., climate and soil) across fields and years, which can confound the effect of a given management practice on yield. Here we evaluated two approaches to group producer fields based on biophysical attributes: (i) a technology extrapolation domain spatial framework (‘TEDs’) that delineates regions with similar (long-term average) annual weather and soil water storage capacity and (ii) clusters based on field-specific soil properties and weather during each crop …

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

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

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

Insufficient Nitrogen Supply From Symbiotic Fixation Reduces Seasonal Crop Growth And Nitrogen Mobilization To Seed In Highly Productive Soybean Crops, Nicolas Cafaro La Menza, Juan Pablo Monzon, John L. Lindquist, Timothy J. Arkebauer, Johannes M.H. Knops, Murray Unkovich, James E. Specht, Patricio Grassini

Department of Agronomy and Horticulture: Faculty Publications

Nitrogen (N) supply can limit the yields of soybean [Glycine max (L.) Merr.] in highly productive environments. To explore the physiological mechanisms underlying this limitation, seasonal changes in N dynamics, aboveground dry matter (ADM) accumula- tion, leaf area index (LAI) and fraction of absorbed radiation (fAPAR) were compared in crops relying only on biological N2 fixation and available soil N (zero-N treatment) versus crops receiving N fertilizer (full-N treatment). Experiments were conducted in seven high-yield environments without water limitation, where crops received optimal management. In the zero-N treatment, biological N2 fixation was not sufficient to meet the N demand of …