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Relative Soybean Response To Aminocyclopyrachlor, 2,4-D, Dicamba, And Aminopyralid, Trey I. Clark

Masters Theses

This research compared the visual symptomology of four auxin herbicides applied at three rates to simulate tank contamination on non-auxin tolerant soybeans. The herbicides examined were aminocyclopyrachlor (ACP), 2,4-D, dicamba, and aminopyralid. The standard labeled rates (SLR) used to base the application rates were 0.12 kg ae ha^-1 for ACP and aminopyralid while dicamba and 2,4-D used 1.12 kg ae ha^-1. These four herbicides exhibit similar symptoms on soybeans which is problematic when diagnosing soybean response. One goal of this project was to obtain high-quality images of the four herbicide’s effect on soybeans, with the hope of …

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 …

The Effects Of Silver Nanoparticles On Soybean (Glycine Max) Growth And Nodulation, Paul J. Boersma

Electronic Thesis and Dissertation Repository

Due to their antimicrobial properties, silver nanoparticles (AgNPs) have become more popular in consumer and industrial products, leading to increasing agricultural and environmental concentrations. Exposure to AgNPs could be detrimental to plants, microbes, and their symbiotic relationships. When subjected to 10 µg/mL AgNPs in a 96-well plate, growth of Bradyrhizobium japonicum USDA 110 was halted. In hydroponic culture with 2.5 µg/mL AgNPs, biomass of inoculated Glycine max (L.) Merr. was 50% of control. Axenic plants were unaffected by this dose, but growth was inhibited at higher doses, indicating that AgNPs inhibit both nodulation and growth. Nodules treated with 2.5 µg/mL …

A Remote Sensing Driven Geospatial Approach To Regional Crop Growth And Yield Modeling, Sadia Alam Shammi

Theses and Dissertations

Agriculture and food security are interlinked. New technologies and instruments are making the agricultural system easy to operate and increasing the food production. Remote sensing technology is widely used as a non-destructive method for crop growth monitoring, climate analysis, and forecasting crop yield. The objectives of this study are to (1) monitor crop growth remotely, (2) identify climate impacts on crop yield, and (3) forecasting crop yield. This study proposed methods to improve crop growth monitoring and yield predictions by using remote sensing technology. In this study, we developed crop vegetative growth metrics (VGM) from the MODIS (Moderate Resolution Imaging …

Identification And Evaluation Of Mycotoxins Produced By Macrophomina Phaseolina, Vivek Hemant Khambhati

Theses and Dissertations

The fungus Macrophomina phaseolina (Tassi) Goidanich (Mp) is the causal agent of charcoal rot in soybean and infects over 500 plant species worldwide. Mp produces various mycotoxins and is suspected of utilizing a toxin-mediated process to penetrate host tissue. Identification and evaluation of secondary metabolites produced by Mp will further elucidate the pathogenesis mechanisms used by the fungus. Mp cultures isolated from soybean were evaluated for phytotoxicity in a hydroponic soybean bioassay and chemically analyzed by LC-MS/MS. All Mp cultures at two dilutions induced phytotoxicity symptoms including chlorosis, necrosis, wilting, stunting, and death. Analysis identified 13 unreported secondary metabolites including …

Spatial Distributions Of Arthropods In Soybean And Implications For Pest Management, Anthony Daniel Greene

All Dissertations

Site-specific management of insect pests of field crops has the potential to decrease control costs and environmental impacts associated with traditional pest management tactics, but the success of these programs relies on the accurate characterization of arthropod distributions within a crop. Although the expense of the fine-scale spatial sampling required for management zone identification in fields may offset the overall reduction in costs achieved with site-specific pest management, the correlation of arthropod counts with ground-based and remotely sensed field attribute data could help to make site-specific pest management programs more profitable. In this study, we chose to determine how insect …

Fungicide Sensitivity Screening Of Corynespora Cassiicola In Us Soybean And Cotton, Tyler Miles Smith

Doctoral Dissertations

Target spot, caused by the fungus Corynespora cassiicola, is a foliar disease of cotton and soybean. Target spot has become a disease of concern in soybean and cotton production systems. Data for fungicide sensitivity and understanding potential impact on yield is lacking for C. cassiicola. Fungicide resistance is also a concern in C. cassiicola with the increase in resistant pathogens in soybean. With the lack of knowledge about baseline fungicide sensitivity and the concern of fungicide resistance the objectives of this study were: (i) to evaluate fungicide products and mixes in small plot soybean and cotton trials, (ii) …

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 …

Evaluation Of Soybean [Glycine Max (L.) Merr.] Quality Following Automatic Fungicide And Harvest Aid Applications Under Delayed Harvest Conditions In The Mid-Southern U. S., Robert Louis Adams Ii

Theses and Dissertations

Soybean growers in the mid-southern U.S. face many challenges imposed by adverse weather conditions that vary spatially and temporally. As a result, growers experience variations in soybean seed quality, grain quality, and yield. While not every harvest season experiences extremes in environmental conditions, those that do may result in major quality issues that could lead to significant financial losses. Therefore, the objective of this research was to evaluate quality as it relates to delayed harvest conditions for soybean following common management practices such as fungicide application to mitigate spread of pathogens or harvest aid application to facilitate more efficient harvest. …

Characterization And Bioactive Properties Of Young And Mature Soybean And Their Protein Hydrolysates, Amna Khalifa Mohammed Alnuaimi

Theses

Soybeans are known for their high protein content that could be substituted for animal proteins. The potential bioactive properties of mature soybean (MS) proteins and their hydrolysates have been widely explored. The aim of this study was to investigate and compare various in-vitro bioactive properties (antioxidant, anti-diabetic, anti-obesity, and anti-inflammatory) of young soybean (YS) and MS flour and their protein hydrolysates when subjected to in-vitro simulated gastrointestinal digestion (SGID) and enzymatic hydrolysis, respectively. In the first phase, SGID of YS and MS flour was carried out to mimic the human digestion, while in the second phase, enzymatic hydrolysis of the …

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 …

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

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 …

Mapping Genetic Resistance To Reniform Nematode (Rotylenchulus Reniformis) In Soybean, Juliet Elizabeth Fultz Wilkes

All Dissertations

Soybean is an important legume crop worldwide. Plant-pathogenic nematodes are common pests that often rob the plant of optimal performance and, therefore, reduce yield potential. Reniform nematode (Rotylenchulus reniformis) is a soil-borne, plant-parasitic nematode found in a wide range of soil textures in tropical to subtropical environments and is capable of infecting soybean. The objectives of this research were to 1) identify quantitative trait loci (QTL) associated with soybean host suitability to reniform nematode using a breeding population carrying genetic resistance from the soybean genotype Forrest, 2) develop and validate molecular markers for use in identifying reniform nematode …

Defining Bee Pollinator Community Composition In Tennessee Soybean, Andrew L. Lawson

Masters Theses

Two planting dates of various soybean varieties were planted in Jackson and Knoxville, TN during 2018 and 2019 with the overall intent of surveying the diversity bee (Hymenoptera) genera in these agroecosystems and also to assess the potential for using late maturing soybean as a food resource for bees during the dearth of floral resources that often occurs during the fall. We also investigated how manipulating planting dates and soybean variety selection affected the occurrence of insect pests that occurred in the soybean.

Both active (netting) and passive (bee bowls and blue-vane traps) sampling were used to collect the bees, …

Pyritic Lignite As A Source Of Iron For Soybean As Influenced By Variety And Soil Ph., Andrea Paola Elvir Flores

Theses and Dissertations

Iron deficiency chlorosis (IDC) is a frequent problem in soybean [Glycine max (L.) Merr.] production on calcareous soils. Greenhouse and soil incubation experiments were established to evaluate pyritic lignite efficacy to supply Fe as compared to Fe-EDDHA and Fe-EDTA sources across contrasting IDC tolerance varieties grown on a slightly acid and a calcareous soil. Soybean IDC incidence was influenced by the soil properties and variety tolerance. All iron sources increased plant dry matter accumulation on the Leeper soil, whereas on the Marietta soil only lignite at 0.672 kg ha-1 produced an increase. Lignite at 0.336 kg ha-1 successfully improved Fe …

Effects Of Cover Crop Management On Biologically Related Soil Properties In A Mississippi Dryland Soybean System, Sapana Pokhrel

Theses and Dissertations

Soil microorganisms are important for the stabilization and preservation of a good soil structure. Management practices can affect the diversity and population of microorganisms, which could beneficially change soil properties and promote a more sustainable dryland system. This study was established near Pontotoc, MS on Atwood silt loam to evaluate the impacts of cover crops and fertilizer sources on selected biologically related soil properties in a no-tillage, dryland soybean system. Soil analyses included total carbon and nitrogen, permanganate oxidizable carbon (POXC), easily extractable glomalin-related soil protein (EE-GRSP), water stable aggregate (WSA) and soil pH. Cover crop biomass and percent groundcover, …

Evaluation Of Economics And Management In Mid-South Soybean Production, Richard Turner

Theses and Dissertations

Two studies were conducted from 2017 – 2019 at Stoneville, MS the first was to determine optimum seeding rates on single and twin row configuration during both late and early planting dates. The second study was to compare two row configurations with two planting populations (whole plot) but add management strategies (subplots) within each whole plot. From this data, yield optimization could be reached within each system that likely encompasses everything a producer in the Mississippi Delta could encounter during a growing season. Soybean seed from this data was analyzed for protein, oil, and fatty acid composition to determine which …

Quantitative Trait Loci Analysis Of A Ril Soybean Population To Determine Chromosomal Regions Governing Seed Protein, Oil, And Linolenic Acid Content, Ronald E. Moore

Masters Theses

180 RILs (recombinant inbred lines) segregating for protein, oil, and fatty acids were produced from a cross between TN12-4098 and TN13-4303. These lines were grown across three locations spread horizontally across Tennessee: Research Education Center at Milan (RECM), Highland Rim Research and Education Center (HRREC), and East Tennessee Research and Education Center (ETREC) in 2018 and 2019. 21 quantitative trait loci (QTLs) spanning 7 chromosomes were found using WinQTLCart2.5.

Influence Of Traditional And Dual-Use Cropping On Arthropods And Slugs In Soybean In Tennessee, Matthew L. Longmire

Masters Theses

Soybean is the number one agricultural crop in Tennessee for both number of hectares planted and economic value. Soybean, used in various products, is marketed globally. In recent years, Tennessee soybean growers have shown an increased interest in the use of cover crops with soybean. A cover crop is planted before the cash crop and can minimize some weeds, diseases, insects, and other pests. Traditionally, cover crops are terminated in the spring before cash crop planting. Traditional methods of cover cropping provide many benefits but can also produce some undesired results. Dual-use cover cropping is a newer method of cover …

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

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 …

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 …

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)] …

Mapping And Identification Of Qtl Associated With Soybean Seed Protein, Oil, And Yield In 5601t × U99-310255 Ril Population Using Snp Genotyping, Mia Justina Cunicelli

Doctoral Dissertations

Soybean [Glycine max (L.) Merr.] is the world’s leading source of vegetable oil and high quality protein meal. However, soybean protein and oil and protein and yield are negatively genetically correlated. Agronomic and seed quality traits of soybean lines are important because they lead to increased soybean value. Molecular markers have played and will continue to play a major role in the genetic characterization and improvement of soybeans. Quantitative trait loci (QTL) are regions within a genome that contain genes that influence particular quantitative traits. Identification of QTLs through phenotypic evaluation only is not possible; therefore, to locate, identify, and …

Simulating Soybean-Rice Crop Rotation And Irrigation Strategies In Arkansas Using Apex, Sam Carroll

Biological and Agricultural Engineering Undergraduate Honors Theses

Rice is one of the most prevalent and relied upon resources around the world. Despite such prominence, cultivation techniques for this crop are not perfect. Precise irrigation amounts and optimal crop rotations are still not completely understood. As the global population continues to grow and resources are depleted, maximizing the efficiency of cropping systems becomes more urgent. The goal of this study was to shed light on these questions using the Agricultural Policy/Environmental eXtender (APEX) model to simulate five fields in soybean-rice rotation in Arkansas. First, the model was calibrated to accurately represent the observed yields in the area. Then, …

Refinement And Validation Of Soybean Looper (Chrysodeixis Includens) (Walker) Thresholds In Mississippi Soybeans (Glycine Max (L.) Merr.), Mary Huff

Theses and Dissertations

Experiments were conducted to refine and validate the soybean looper, Chrysodeixis includens (Walker) threshold in Mississippi soybeans, Glycine max. (L.) Merr. Equivalencies between sweep net and drop cloth sampling methods were evaluated, overall the sweep net was more effective at capturing soybean looper larvae greater than third instar and larvae less than or equal to third instar when compared to the drop cloth method. Feeding studies were conducted to determine the feeding rates of each instar, results showed that fifth instar larvae consume the greatest amount of leaf tissue, and larvae greater than or equal to third instar consume more …

Investigation Of The Individual Soybean Root Nodule Microbiome, Parris Mica Mayhood

MSU Graduate Theses

Soybean is a valuable crop that establishes a symbiotic association with nitrogen-fixing microorganisms. Previous research suggests members of the genus Bradyrhizobium are the major nitrogen-fixing inhabitants of soybean root nodules. However, results from recent studies identified the presence of other bacteria, so called non-rhizobial endophytes (NREs), inside root nodules. All previous research has pooled nodules of different plants for bacterial community analysis, but this study investigated the presence and relative abundance of rhizobia and NREs within multiple root nodules of a single plant. Three sites were selected on Kendrick Farm in Springfield, MO, where three plants and rhizosphere soil were …

Soybean Root Exudates Increase The Physiological Diversity Of Bacteria In Cadmium-Treated Soil, Leily Kazemi Movahed

Electronic Thesis and Dissertation Repository

Three soybean cultivars with contrasting retention of cadmium (Cd) in the root were grown in Cd-spiked nutrient solution and used to determine that symplastic compartmentalization of Cd in roots is probably responsible for retention of Cd in roots. Roots of the low Cd-accumulator AC Hime treated with 30 mM Cd exuded up to 10-fold higher concentrations of citric, succinic, fumaric and malic acids into the hydroponic solution when compared to control; concentrations of the same organic acids from the high Cd-accumulator Westag 97 increased by up to 3-fold. The same cultivars were grown in Cd-spiked soil and the physiological profiles …