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Evaluation Of Weed Control Efficacy And Crop Tolerance To Florpyrauxifen-Benzyl Coated Onto Urea, Bodie Lyn Cotter
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 …
Breeding Soybean [Glycine Max (L) Merr.] Under Reduced Irrigation, Francia Seconde Ravelombola
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 …
Screening And Breeding Soybean For Flood Tolerance, Maria Roberta De Oliveira
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 …
Crop Response To Low-Dose Dicamba, Mason Castner
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 …
Association Mapping For Soybean (Glycine Max L. Merr.) Protein And Oil Content, Joseph Najjar
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 …
Genetics Of Physiological Traits Associated With Drought Tolerance In Soybean (Glycine Max), Sumandeep Kaur Bazzer
Genetics Of Physiological Traits Associated With Drought Tolerance In Soybean (Glycine Max), Sumandeep Kaur Bazzer
Graduate Theses and Dissertations
Soybean (Glycine max L.) is one of the major row crops in the United States, and its production is often limited by drought stress. Physiological traits from exotic germplasm that confer drought tolerance may be useful in improving commercial soybean production. For example, carbon isotope ratio (δ13C) is positively correlated with water use efficiency (WUE), and nitrogen isotope ratio (δ15N) is negatively correlated with N2 fixation; canopy temperature (CT) is an indicator for genetic variation in transpiration and stomatal conductance. Therefore, the objectives of this research were to identify the genomic regions associated with: (1) δ13C and δ15N using a …
Developing A High-Throughput Method To Screen Soybean Germplasm For Hypoxia Tolerance In Hydroponic Systems, Derrick Harrison
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 …
The Effects Of Seed-Applied Fluopyram On Root Penetration And Development Of Meloidogyne Incognita On Cotton And Soybean, Tracy Hawk
Graduate Theses and Dissertations
Plant-parasitic nematodes are major pests of cotton and soybean in Arkansas, and across the Southern United States. These nematodes cause more than $3 billion worth of crop losses each year, in part due to lack of available control tactics, such as nematicides. Fluopyram has recently been registered as a seed-treatment nematicide in agronomic crops. The toxicity of fluopyram against Meloidogyne incognita infection has been reported, however, information on root protection provided by fluopyram against Meloidogyne incognita is lacking. The first objective of this research was to evaluate the effect seed-applied fluopyram had on nematode development, root galling, and reproduction on …
Mitigating Herbicide Impacts To Soybean, Grant Lawson Priess
Mitigating Herbicide Impacts To Soybean, Grant Lawson Priess
Graduate Theses and Dissertations
The rapidity in evolution of herbicide-resistant weeds and the resulting cost to U.S. farmers demonstrate the need to responsibly steward the limited number of herbicides available in agricultural systems. To reduce weed emergence and likewise added selection pressures placed on herbicides, early-season crop canopy formation has been promoted. However, impacts to soybean following a potentially injurious herbicide application have not been thoroughly evaluated. Therefore, field experiments were conducted to determine whether: 1) soybean injury from metribuzin or flumioxazin delayed canopy formation or changed the incidence of pathogen colonization; 2) residual herbicides applied preplant reduced the potential for soybean injury and …
Studies On Pathogenesis Of The Diseases Caused By Macrophomina Phaseolina And Phomopsis Longicolla On Soybean, Marcio Leizer Zaccaron
Studies On Pathogenesis Of The Diseases Caused By Macrophomina Phaseolina And Phomopsis Longicolla On Soybean, Marcio Leizer Zaccaron
Graduate Theses and Dissertations
Soybean (Glycine max), a legume, is an economically important crop in many parts of the world, including the USA, Brazil, Argentina, China, and India, currently the top five producing countries. Soybean is primarily used as feed, with incising markets for food and biodiesel. Similar to most crops, soybean yield and quality are affected by a diverse group of plant pathogens. In particular, several species of filamentous fungi have been the cause of severe yield losses in most growing regions world-wide. The soil born fungus Macrophomina phaseolina, causal agent of charcoal rot, has been found to be endemic to several soybean …
Molecular Basis Of Pathogenesis And Host Determination In Cercospora Sojina: From Phenotypic To Genotypic Patterns, Wagner Calegari Fagundes
Molecular Basis Of Pathogenesis And Host Determination In Cercospora Sojina: From Phenotypic To Genotypic Patterns, Wagner Calegari Fagundes
Graduate Theses and Dissertations
Frogeye leaf spot (FLS), caused by Cercospora sojina, is an important and recurrent disease of soybean in many production regions. Genetic resistance is potentially one of the most cost-effective and sustainable strategies to control FLS. However, C. sojina has already demonstrated the ability to overcome resistance conveyed by single R-genes (resistance genes) of soybeans, followed by the emergence of new physiological races. Although understanding population genomics and the virulence gene inventories in fungal plant pathogens is extremely important to improve disease control measures, studies regarding host specificity and pathogenesis in C. sojina are very limited. Therefore, the overarching goal of …
Epidemiological Studies Of Soybean Vein Necrosis Virus And Potential Resistance Mechanisms To Its Vector Neohydatothrips Variabilis (Beach), Jing Zhou
Graduate Theses and Dissertations
Soybean (Glycine max (L.) Merrill) is one the most important crops in global agriculture with annual production of over 260 million metric tons. As the dependence of a growing global population to soybean has increased, so does the importance of soybean diseases and pests. Over 200 pathogens attack soybean; among them, viruses pose a major threat to the soybean industries accounting for approximately 10% of the annual yield reduction caused by diseases in the past two decades. Soybean vein necrosis virus (SVNV) is a relatively newly discovered virus causing the homonymous disease. The widespread occurrence of the disease in major …
Linkage Mapping For Soybean (Glycine Max) Flood Tolerance, Wade Stiles Hummer
Linkage Mapping For Soybean (Glycine Max) Flood Tolerance, Wade Stiles Hummer
Graduate Theses and Dissertations
Flood tolerance in soybean (Glycine max) is not a well-characterized trait, yet flooding damage is second only to drought stress in terms of yield reduction. The objectives of this study were to determine genetic variation for flooding tolerance in two populations of soybean recombinant inbred lines (RILs) and to identify and confirm flood tolerant QTL. Population A (WHA) consisted of 111 RILs derived from the cross 5002T by 91210-350 and Population B (WHB) consisted of 79 RILs from the cross RA-452 by Osage. Experiments were conducted at the Rice Research and Extension Center (RREC) near Stuttgart, AR in 2015 and …
Evaluation Of Soybean Maturity Group And Planting Date In A Soybean-Rice Rotation On Overall Crop Productivity, Carrie Ortel
Evaluation Of Soybean Maturity Group And Planting Date In A Soybean-Rice Rotation On Overall Crop Productivity, Carrie Ortel
Graduate Theses and Dissertations
Little is known about the effects of soybean (Glycine max L.) management techniques on soil-nitrogen (N) credit development and its impact on the subsequent rice (Oryza sativa L.) crop’s success. This study was conducted to determine how soybean maturity group (MG) and planting date effect overall soybean productivity and its influence on the following rice crop. Various soybean planting dates (optimum and late) and MGs (3.5, 4.7, 5.4, and 5.6) were grown and followed in rotation with a rice crop. Six rates of pre-flood fertilizer-N (0, 44, 89, 134, 179, 224 kg N ha-1) were applied to the rice crop. …
Physiological Characterization Of The Soynam Parental Lines Under Field Conditions, Akshita Mishra
Physiological Characterization Of The Soynam Parental Lines Under Field Conditions, Akshita Mishra
Graduate Theses and Dissertations
The narrow genetic pool of soybean (Glycine max L. Merr.) in North America can limit its future yield gains. Among the worldwide germplasm collection of 45,000 unique landraces, only 80 contribute 99% to the collective parentage of North American soybean cultivars. Among these 80 landraces, just 17 contribute to 86% of the collective parentage of the modern cultivars. The Soybean Nested Association Mapping population (SoyNAM) was therefore developed with the objective of diversifying the soybean gene pool. Forty diverse soybean genotypes from maturity groups (MG) 1 through 5 were crossed with a common MG 3 parent to develop 40 recombinant …
Genetic And Phytopathological Studies On Charcoal Rot Resistance In Soybean [Glycine Max (L) Merr.], Marcos Paulo Da Silva
Genetic And Phytopathological Studies On Charcoal Rot Resistance In Soybean [Glycine Max (L) Merr.], Marcos Paulo Da Silva
Graduate Theses and Dissertations
Charcoal rot of soybean (Glycine max (L.), caused by Macrophomina phaseolina is a disease of economic significance in the United States. The identification and quantification of the resistance is difficult, and very little is known about the genetics and markers linked to the charcoal rot (CR) resistance genes. Current assay methods can be time consuming, and data may vary between tests. The objectives of this study were to 1) create a robust seed plate assay (SPA) for CR resistance by comparing results with cut-stem and CFUI assays; 2) correlate and compare field data disease assessments with SPA; 3) identify QTLs …
Evaluation Of Dicamba Off-Target Movement And Subsequent Effects On Soybean Offspring, Gordon Travis Jones
Evaluation Of Dicamba Off-Target Movement And Subsequent Effects On Soybean Offspring, Gordon Travis Jones
Graduate Theses and Dissertations
Commercial launch of cotton with resistance to dicamba, glyphosate, and glufosinate occurred in 2015 and launch of soybean with resistance to dicamba and glyphosate occurred in early 2016. It is likely that non-dicamba-resistant soybean will be planted in close proximity to dicamba-resistant soybean and cotton. Therefore, experiments were conducted to examine the distance dicamba moves during an application using commercial application equipment, as well as the effect the drift events have upon soybean offspring. Additional experiments were designed to investigate the effect glyphosate addition to dicamba has upon soybean growth and yield as well as possible effects on offspring. Lastly, …
Dicamba Effects On Soybean (Glycine Max) Growth, Yield, And Offspring, Mark Spencer Mccown
Dicamba Effects On Soybean (Glycine Max) Growth, Yield, And Offspring, Mark Spencer Mccown
Graduate Theses and Dissertations
Introduction of a new dicamba-resistant (Xtend) trait in soybean and cotton will increase dicamba herbicide use. Consequently, concern for injury to sensitive crops from off-target movement and tank contamination will likely increase. For soybean, foliar symptoms associated with dicamba damage do not necessarily reflect yield losses; hence, experiments were conducted to determine the effects of dicamba on soybean growth, yield, and offspring. Low rates of dicamba [1/64X (8.75 g ae ha-1) and 1/256X (2.18 g ae ha-1) of a normal 1X field rate (560 g ae ha-1)] were applied at two vegetative growth stages (V4, V6) and at each reproductive …
Horizontal Transmission Of Helicoverpa Armigera Nucleopolyhedrovirus (Hearnpv) In Soybean Fields Infested With Helicoverpa Zea (Boddie), Joseph Lee Black
Horizontal Transmission Of Helicoverpa Armigera Nucleopolyhedrovirus (Hearnpv) In Soybean Fields Infested With Helicoverpa Zea (Boddie), Joseph Lee Black
Graduate Theses and Dissertations
Helicoverpa armigera Nucleopolyhedrovirus (HearNPV) is a commercially available viral biopesticide that targets Heliothines, including Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae), the most damaging pest of soybean (Glycine max (L.) Merrill) in the Mid-South. Previous formulations of HearNPV have been well studied; however, no research has been published on current formulations. The first objective of this thesis was to assess the rate of horizontal transmission of HearNPV in a soybean field infested with H. zea when HearNPV was applied as a bio-insecticide, and to identify arthropods that are important obligate carriers in dissemination. HearNPV spread 200 feet in 3 fields, and was …
Characterization Of The Relationships Between Soybean Yield, Trifoliolate Leaf Chloride Concentration, And Cultivar Chloride Inclusion/Exclusion Rating, Dillon Cox
Graduate Theses and Dissertations
Chloride toxicity is recognized as yield limiting problem in soybean [Glycine max (L.) Merr.] production. Limited information is available to accurately diagnose and manage Cl toxicity. The only recommendation for Cl toxicity management is to plant an excluder cultivar, however the cultivar Cl sensitivity rating system (excluder, includer, and mixed) does not appear to capture the variability in cultivar Cl tolerance. The objectives of this research were to i) develop critical tissue-Cl concentrations in which yield loss occurs for excluder and includer cultivars and ii) investigate the variability in cultivar Cl ratings. A study was conducted across five site-years using …
Genomic And Physiological Approaches To Improve Drought Tolerance In Soybean, Avjinder Kaler
Genomic And Physiological Approaches To Improve Drought Tolerance In Soybean, Avjinder Kaler
Graduate Theses and Dissertations
Drought stress is a major global constraint for crop production, and improving crop tolerance to drought is of critical importance. Direct selection of drought tolerance among genotypes for yield is limited because of low heritability, polygenic control, epistasis effects, and genotype by environment interactions. Crop physiology can play a major role for improving drought tolerance through the identification of traits associated with drought tolerance that can be used as indirect selection criteria in a breeding program. Carbon isotope ratio (δ13C, associated with water use efficiency), oxygen isotope ratio (δ18O, associated with transpiration), canopy temperature (CT), canopy wilting, and canopy coverage …
Dissecting Salt Tolerance In Soybean By Profiling Differential Physiological Responses Under Salt Stress, Jade Amber Newsome
Dissecting Salt Tolerance In Soybean By Profiling Differential Physiological Responses Under Salt Stress, Jade Amber Newsome
Graduate Theses and Dissertations
Saline soils are common worldwide and limit the yield potential of many crops. Plants respond in a variety of ways to the stress imposed by saline soils. Plants under salt stress must first sense their surroundings and transmit a signal alerting the rest of the plant to the saline conditions. Salt tolerance in soybeans is typically defined by exclusion of chloride ions from foliar tissues. Though differences in ion uptake among soybean genotypes is well documented, the key mechanisms employed by tolerant cultivars to cope with salt stress on the whole-plant level are still largely unknown. Objectives of the current …
Soil And Plant Property Differences Among High-Yield Soybean Areas In Arkansas, Taylor Cass Adams
Soil And Plant Property Differences Among High-Yield Soybean Areas In Arkansas, Taylor Cass Adams
Graduate Theses and Dissertations
Continued achievement of soybean [Glycine max (L.) Merr.] yields greater than 6719 kg ha-1 (100 bu ac-1) will depend on decreasing the yield gap, which is contingent on gathering more information regarding the soil physical, chemical, and microbiological environment and the main plant factors contributing to high-yield soybean. Therefore, understanding the main factor differences between high- and average-yield areas may provide insight for making management decisions to increase yields. The objectives of this study were i) to evaluate the effects of region and soil depth on soil property differences between high- and average-soybean-yielding areas, ii) to determine which soil properties …
Quantitative Trait Loci Mapping, Genome-Wide Association Analysis, And Gene Expression Of Salt Tolerance In Soybean, Ailan Zeng
Graduate Theses and Dissertations
Salt stress is a common abiotic stress causing yield reduction in soybean. There are differential responses, namely tolerance (excluder) and intolerance (includer), among soybean germplasm. However, the genetic and physiological mechanism for salt tolerance is not clear. Identification of novel QTL for salt tolerance and genes that are differentially expressed under salt stress would help elucidate the salt tolerance mechanism and facilitate the development of salt tolerant cultivars through marker assisted selection (MAS). The objectives of this study were to identify new QTL or genes responsible for salt tolerance using three approaches: QTL mapping, association analysis, and RNA sequencing (RNA-seq). …
Selection Of Drought-Tolerant Soybean Lines Using A Field Screening Method And Identification Of Qtls For Slow Wilting And Nitrogen Fixation Associated With Drought-Tolerance, Mirta Beatriz Dalzotto
Selection Of Drought-Tolerant Soybean Lines Using A Field Screening Method And Identification Of Qtls For Slow Wilting And Nitrogen Fixation Associated With Drought-Tolerance, Mirta Beatriz Dalzotto
Graduate Theses and Dissertations
Drought causes significant yield reductions in soybean. The development of drought-tolerant cultivars is an effective alternative to overcome this abiotic stress. Slow wilting, prolonged nitrogen fixation, and minimal yield reduction under water stress play an important role in evaluating breeding materials. Despite advances in knowledge about plant responses to drought conditions, there is little information on effective methodologies for phenotype screening in the field, and some QTLs have been identified for drought tolerance. Field screenings under drought and irrigated conditions are necessary to detect drought tolerant lines. In addition, QTLs and molecular makers associated with drought tolerance traits will greatly …
High Throughput Phenotypic Evaluation Of Drought-Related Traits In Soybean, Hua Bai
High Throughput Phenotypic Evaluation Of Drought-Related Traits In Soybean, Hua Bai
Graduate Theses and Dissertations
Drought limits crop growth and yield in soybean. Rapid and effective methods of screening large numbers of soybean lines for drought tolerance are urgently needed. Two experiments were conducted to evaluate the effects of drought in soybean during reproductive stages. In the first experiment five genotypes from maturity groups 2 through 5 were tested under well-irrigated and drought conditions. Beginning at R5, leaf samples were taken for nitrogen concentration analysis. Pictures were taken across the top of each plot to determine the intensity of greenness using the Dark Green Color Index (DGCI). Aerial photographs were also taken to determine aerial …
Genetic Analysis Of Soybean Mosaic Virus (Smv) Resistance Genes In Soybean [Glycine Max (L.) Merr.], Mariola Klepadlo
Genetic Analysis Of Soybean Mosaic Virus (Smv) Resistance Genes In Soybean [Glycine Max (L.) Merr.], Mariola Klepadlo
Graduate Theses and Dissertations
Soybean mosaic virus (SMV) causes the most serious viral disease in soybean worldwide. Seven SMV strains, G1 - G7, and three independent multi-allelic loci for SMV resistance, Rsv1, Rsv3, and Rsv4, have been identified. In the initial study, 299 soybean germplasm lines were genotyped for Rsv4 region, inoculated with SMV-G1 and G7 strains, and classified into several resistance groups. The Glyma.02g121400 locus was sequenced from ten soybean accessions, and alignment of the sequences revealed three SNPs displaying 100% polymorphic consistency when a soybean genotype carrying the Rsv4 gene was present. A cross between V94-5152 × Lee 68 was made to …
The Effects Of Meloidogyne Incognita And Heterodera Glycines On The Yield And Quality Of Edamame In Arkansas, Juliet Fultz
The Effects Of Meloidogyne Incognita And Heterodera Glycines On The Yield And Quality Of Edamame In Arkansas, Juliet Fultz
Graduate Theses and Dissertations
Edamame (Glycine max), also known as vegetable soybean, was introduced to the United States from Japan in 1890 and has been growing in popularity as a nutrient-rich, low-sugar snack in recent years. In 2012, the American Vegetable Soybean and Edamame, Inc. established the first domestic commercial processing plant in Mulberry, Arkansas and contracted local growers for production. Since the crop is harvested when seed are immature, management practices are different from those for traditional soybean. Plant-parasitic nematodes, particularly Meloidogyne incognita (southern root-knot) and Heterodera glycines (soybean cyst), are common in Arkansas and are pests of concern for edamame growers. Edamame …
Soybean Planting And Risk-Return Tradeoffs In The Mid-Southern United States, Weston Weeks
Soybean Planting And Risk-Return Tradeoffs In The Mid-Southern United States, Weston Weeks
Graduate Theses and Dissertations
This thesis is comprised of two studies on the effects of soybean (Glycine max (L.) Merr.) planting date (PD) and maturity group (MG) selection on producer expected returns. Having to replant soybean after early-season planting because of poor stand establishment is costly for producers. Replanting costs have increased in the last ten years as seed and other input costs for soybean have increased. Using five years of field trial results from two locations in Arkansas, the yield response to early and late season plant population density has been estimated to determine yield and future revenue potential for the purpose of …