Life Sciences Commons^™

Use Of Foliar Chemical Treatments To Induce Disease Resistance In Rhododendrons Inoculated With Phytophthora Ramorum, Craig Ramsey, Paul C. Freebury, Debra H. Newman, Wolfgang Schweigkofler, Leland J. Cseke, Steven E. Newman

Natural Sciences and Mathematics | Faculty Scholarship

A field study was conducted at the National Ornamental Research Site at Dominican University California (NORS-DUC). The study goal was to evaluate three chemical inducers applied as foliar treatments for controlling Phytophthora ramorum, on Rhododendron x ‘Cunningham’s White’ nursery plants. The inducers were chlorine dioxide (ElectroBiocide), hydrogen peroxide (OxiDate 2.0), and acibenzolar-s methyl (Actigard). Water samples from the electrostatic sprayer were measured for three physicochemical water properties. Visual assessment of plant foliage, based on the Horsfall- Barratt scale, was conducted at three and five months after chemical treatments. Foliar fluorescence (Fv/Fm) was measured over three dates. The success of P. …

White Pine Blister Rust Distribution In New Hampshire 1900-2018: Exploring The Impacts Of An Exotic Pathogen On Forest Composition And Succession, Janine Marr

Antioch University Full-Text Dissertations & Theses

White pine blister rust (WPBR) has been affecting New Hampshire’s white pines for more than a century, yet no data exist on the long-term effects of the non-native disease on the state’s forests, particularly with respect to the regeneration and sustainability of white pine, and forest succession. This study aimed to address the gaps in the literature by exploring: 1) the current distribution, incidence, and severity of WPBR in New Hampshire; 2) the application of two historical hazard ratings models, one climatic, and one biotic; and 3) the long-term effects of the disease on forest composition, structure, and succession. Historical …

Introduction To Special Issue Of Plant Virus Emergence, Michael M. Goodin, Jeanmarie Verchot

Plant Pathology Faculty Publications

No abstract provided.

Characteristics Of Cercospora Nicotianae With Reduced Sensitvity To Azoxystrobin, William Barrett Barlow

Theses and Dissertations--Plant Pathology

Burley and dark tobacco production are important to agriculture in Kentucky, worth $145.1 and $94.4 million in 2020, respectively. The price received for a tobacco crop is influenced by leaf quality, determined by multiple characteristics including leaf damage. Frogeye leaf spot (FLS), caused by Cercospora nicotianae, has historically been a minor disease of tobacco. However, when FLS infections reach the upper canopy of tobacco, lesions are seen as damage that negatively influence leaf quality. Fungicides are regularly used to manage foliar diseases of tobacco, and the only systemic fungicide active ingredient labeled for tobacco is azoxystrobin. Azoxystrobin belongs to the …

The Roles Of The Actin Network And Co-Opted Host Factors In Tbsv Replication, Melissa Gabriela Molho Medina

Theses and Dissertations--Plant Pathology

Positive-stranded (+) RNA viruses are the largest family of viruses that infect plants, causing important economic losses in different crops. Tomato bushy stunt virus (TBSV), a small positive-stranded RNA virus, has emerged as a model virus to study virus-host interactions. TBSV encodes for only five proteins, therefore, to infect the host cell TBSV co-opts selected host components and subverts specific molecular pathways.

Firstly, I performed a proteomic screening using Arabidopsis proteins. I found that TBSV viral replication proteins interact with 88 host proteins, including the ubiquitin-conjugating enzyme 2 (Ubc2), fructose 1,6 biphosphate aldolase (Fba1), and several members of the Hps70 …

Evaluation Of Corn Agronomic Management Practices Following A Rye Cover Crop, Daniel John Quinn

Theses and Dissertations--Plant and Soil Sciences

Fall implementation of a rye (Secale cereale L.) cover crop (RCC) prior to spring corn (Zea mays L.) planting is a management practice used to improve soil conservation, water quality, and limit herbicide dependence. However, corn growth and yield following a RCC is often reduced due to early-season nitrogen (N) stress and decreased plant emergence, which can limit RCC adoption. The objective(s) of this research were to evaluate corn agronomic management practices (e.g., N and seeding rate management, in-furrow (IF) starter use) following a RCC and determine which management practices can be used to limit corn stress following …

Wheat Disease Management With Fungicides: Qoi-Resistant Parastagonospora Nodorum And Zymoseptoria Tritici, Application Timing For Leaf Disease Management, And Sprayer Configurations For Fusarium Head Blight Management, Nathaniel Heubeck White

Theses and Dissertations--Plant Pathology

Disease management in winter wheat can be improved by a properly implemented foliar fungicide program. The fungicide, application time, and application system should be selected based on the host, pathogens present, risk of fungicide resistance, and time of disease onset. These factors vary among environments and require region-specific research to determine appropriate practices. Trials were conducted to evaluate different aspects of fungicide applications for managing Fusarium head blight (FHB), caused by Fusarium graminearum, and the Septoria tritici leaf blotch complex, caused by Zymoseptoria tritici and Parastagonospora nodorum. A survey of P. nodorum isolates from Kentucky and Illinois and …

Seeing Double With Cannabis: Heteroploid Populations In Bipolaris Gigantea, Causal Agent Of Bipolaris Leaf Spot, Desiree Szarka

Theses and Dissertations--Plant Pathology

Bipolaris leaf spot (BLS) disease emerged with the reintroduction of hemp as a crop in the United States following more than 60 years of prohibition. The causal agent was identified as Bipolaris gigantea (=Drechslera gigantea), a known minor pathogen of monocots which causes devastating disease on hemp. BLS has been confirmed throughout Kentucky and reported in 15 states. Morphology and growth characteristics of isolates from eight counties across Kentucky were similar with the exception of some isolates producing protoperithecial-like structures. Phylogenetic and whole genome analysis indicated that some isolates were haploid, containing a single allele at each gene …

Negative Regulatory Factors In Tombusvirus Replication: Known Proteins, Novel Roles, Paulina Alatriste González

Theses and Dissertations--Plant Pathology

Although host cells are a rather rich source for co-opted host factors, lipids and metabolites, positive stranded RNA viruses vastly rewire cellular pathways and remodel cellular membranes to support viral replication. To accomplish such major changes, these viruses depend on the availability of different host factors and the ability to readily assemble viral replication organelles (VROs). Genome-wide screens and proteomics approaches with Tomato Bushy Stunt Virus (TBSV) in a yeast model host indicated that tombusviruses rely on the cellular cytoskeleton to reorganize the cellular environment of their hosts. Using temperature-sensitive (ts) mutants of beta and gamma-tubulin proteins and pharmacological inhibitors, …

Assaying Bacillus Amyloliquefaciens Isolates 1ba And 1d3 For Biosurfactant Production And Utilization Of Petroleum Hydrocarbons And Phenolic Acids, Pavan Kulkarni

Electronic Theses and Dissertations

Several Bacillus amyloliquefaciens isolates obtained from wheat residue have been studied as biological agents to control wheat diseases. Notable traits of isolates 1BA and 1D3 include growth with high salt (10% NaCl), at temperatures up to 50°C and over a wide pH range. BIOLOG Gen III plates were used to study and further characterize Bacillus amyloliquefaciens 1BA and 1D3. Both isolates showed tolerance to high salt concentration supporting previous studies. They also grew in the presence of lithium chloride, potassium tellurite, and sodium bromate. Both isolates grew at pH 5, with almost identical carbon source utilization fingerprints. However, D-serine, quinic …

Winter Wheat Response To Different Fungicide Management (Products And Timing Of Application) During The 2019-2020 Growing Season, G. Cruppe, B. R. Jaenisch, R. P. Lollato

Kansas Agricultural Experiment Station Research Reports

Foliar fungicides can improve wheat grain yield in Kansas, but there is limited information on the efficacy of different products as well as the timing of application. We conducted a field study in five Kansas locations to evaluate the yield, test weight, and protein responses of WB-Grainfield to different commercial fungicides applied at different times during the growing season. The trial was conducted in a randomized complete block design to evaluate (1) a non-treated control; Topguard applied at 5 ounces per acre at (2) jointing, (3) heading, and (4) jointing plus heading; (5) Delaro applied at 6 oz/a at jointing; …

Winter Wheat Variety Response To Flag Leaf Foliar Fungicide Application In 2019–2020, G. Cruppe, B. R. Jaenisch, R. P. Lollato

Kansas Agricultural Experiment Station Research Reports

Foliar fungicide can be an important tool in improving wheat yields, but its effectiveness is season- and variety-dependent. To evaluate the yield, test weight, and protein responses of different commercial winter wheat varieties to one foliar fungicide application around heading, we conducted a trial combining four winter wheat varieties and two fungicide management treatments in Manhattan during 2019–2020. The control treatment consisted of no fungicide application, and the alternative treatment consisted of 5 oz/a Absolute Maxx + NIS applied at heading. Varieties evaluated were Bob Dole, Larry, WB4269, and Zenda. The study was conducted under no-tillage practices following a previous …

Winter Wheat Variety Response To Timing And Number Of Fungicide Applications During The 2019–2020 Growing Season In Kansas, G. Cruppe, B. R. Jaenisch, B. Valent, R. P. Lollato

Kansas Agricultural Experiment Station Research Reports

The objective of this project was to evaluate the yield response of different winter wheat varieties to different fungicide management treatments during the 2019–2020 growing season in Kansas. Fourteen varieties were evaluated under four fungicide treatments (no fungicide, application either at jointing, heading, or at both stages) in five locations across Kansas in a split-plot design. Disease incidence was assessed approximately 20-d after each fungicide application. Septoria blotch and tan spot were the most prevalent early-season diseases at the studied fields, while stripe rust, leaf rust, and tan spot prevailed late in the season. Late-season diseases had a greater effect …

Impact Of Fungicide On Wheat, G. F. Sassenrath, H. Zhao, X. Lin

Kansas Agricultural Experiment Station Research Reports

This is a report of research to test the impact of fungicide and management on wheat yield and quality. Fusarium head blight (FHB), or scab, is a persistent problem in wheat production, especially in high rainfall areas such as eastern Kansas. Two cultivars of winter wheat varying in FHB sensitivity (Everest, moderately resistant, and KanMark, susceptible) were tested for control of FHB using fungicide treatments made to the seed prior to planting or to the wheat plant at heading, in tilled or no-tilled management. The wet spring of 2020 resulted in high FHB pressure, but dry conditions at harvest re­duced …