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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 …
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 …
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 …
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 Seed Quality And Vigor: Influencing Factors, Measurement, And Pathogen Characterization, Kimberly Ann Cochran
Soybean Seed Quality And Vigor: Influencing Factors, Measurement, And Pathogen Characterization, Kimberly Ann Cochran
Graduate Theses and Dissertations
High seed vigor (SV), or the ability of seed to germinate and grow in a stressful environment is important, as many field emergence conditions are stressful for germination. Soybean SV can be affected by cultivar, seed storage environment conditions, the growing environment during seed development, crop management practices such as foliar fungicide applications, pathogens, and other factors. To assess the effects of some of these factors on soybean, the objectives of this work were to determine 1. the effect of cultivar and foliar azoxystrobin application on soybean yield, germination, vigor, microflora, and their relationships under harvest delay conditions; 2. if …
The Phenotypic Effects And Transcript Response Of Salt Stress, The Impact Of Viral Infection On Salt Stress Symptoms, And The Effect Of Salt Stress On Soybean Virus Vector Activity In Soybean Varieties That Vary In Chloride Uptake, Alma Glenn Laney
Graduate Theses and Dissertations
With the increase in saline soils worldwide, understanding the mechanisms for salt tolerance in plants is important to reduce yield loss due to salt stress. Soybean, Glycine max (L.) Merr., genotypes differ in chloride uptake with genotypes that take up chloride into foliar tissues tending to be salt-sensitive whereas those that partially exclude chloride from the leaves are more salt-tolerant. Transcriptional and physiological responses were measured in two soybean cultivars, Clark and Manokin, which differ in chloride uptake in response to salt stress and in combination with Soybean mosaic virus (SMV) and its aphid vector, Aphis glycines . The interaction …
Spatial Distributions Of Rhizoctonia Species In Soybean Fields Undergoing Annual Rotations With Rice, Terry Neil Spurlock
Spatial Distributions Of Rhizoctonia Species In Soybean Fields Undergoing Annual Rotations With Rice, Terry Neil Spurlock
Graduate Theses and Dissertations
Aerial blight is caused by Rhizoctonia solani AG1-IA. This pathogen also causes sheath blight of rice. In Arkansas, many soybean and rice fields undergo an annual rotation of these two crops which facilitates a continuous source of inoculum from one year to the next. Aerial blight is a two stage disease in that R. solani AG1-IA colonizes the plant during the early vegetative growth stages and then aerial blight develops after the soybean canopy closes in the later reproductive stages of development. As a result of the upper portion of the canopy often being asymptomatic, significant yield loss can occur …
Soybean (Glycine Max) Response To Imazosulfuron Drift And Carryover From Rice (Oryza Sativa), Sandeep Singh Rana
Soybean (Glycine Max) Response To Imazosulfuron Drift And Carryover From Rice (Oryza Sativa), Sandeep Singh Rana
Graduate Theses and Dissertations
In the Midsouth, soybean is often grown in close proximity to rice or in rotation with rice. Herbicides used in rice can injure soybean via drift or carryover. Consequently, field trials were conducted to determine the response of soybean (cv. AG 4703) to imazosulfuron drift and carryover (at Fayetteville, Marianna, Keiser and Pine Tree, AR) from rice. To assess the potential for carryover, soybean was planted into rice fields treated the previous year with imazosulfuron (rotation study). To evaluate in-season sensitivity of soybean to imazosulfuron (tolerance study) relative to halosulfuron, a common sulfonylurea herbicide applied to rice, both imazosulfuron and …