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Mortality Model For A Perennial Grass In Australian Semi-Arid Wooded Grasslands Grazed By Sheep, K. C. Hodgkinson, W. J. Muller

IGC Proceedings (1977-2023)

No abstract provided.

Selecting Grassland Species For Saline Environments, M. E. Rogers, A. D. Craig, T. D. Colmer, R. Munns, S. J. Hughes, P. M. Evans, P. G. H. Nichols, R. Snowball, D. Henry, J. Deretic, B. Dear, M. Ewing

IGC Proceedings (1977-2023)

In Australia, around 5.7 million hectares of agricultural land are currently affected by dryland salinity or at risk from shallow water tables and this figure is expected to increase over the next 50 years (LWRA, 2001). Most improved grassland species cannot tolerate the combined effects of salt and waterlogging and, therefore, the productivity of sown grasslands in salt-affected areas is low. However, there is potential to overcome the lack of suitably adapted fodder species by introducing new, salt and waterlogging-tolerant species and by diversifying the gene pool of proven species. Potential species include exotic, naturalised and native Australian grass, legumes, …

Grazing Animal Production Systems And Grazing Land Characteristics In A Semi-Arid Region Of Greece, I. Hadjigeorgiou, G. Economou, D. Lolis, N. Moustakas, G. Zervas

IGC Proceedings (1977-2023)

Rough grazing in Greece cover about 40% of the total land area, is publicly owned and managed extensively (Hadjigeorgiou et al., 2002). The Prefecture of Larisa is in the centre of Greece, and has 212,000 ha of rough grazing land, with a variable topography ranging from sea level up to 3,000 m a.s.l. This area is utilized by a total population of 135,000 LU (mainly sheep, goats and some suckler cows), which consumes annually an appreciable fraction of their total nutrient requirements from rough grazing.

The Productivity Of Coastal Meadows In Finland, R. Nevalainen, S. Jaakola, A. Huuskonen, J. Kiljala, E. Joki-Tokola

IGC Proceedings (1977-2023)

The coastal meadows of Finland have gained a new interest as a summer pasture for cattle. These habitats have great historical, aesthetic and biological value (Pessa & Anttila, 2000). Typical features of the coastal meadows are the varying vegetation zones and wet, sometimes waterlogged, soils. The meadows are important nesting and feeding habitats for many water birds. When grazing ceases, reeds, trees and shrubs take over and the area loses its openness. Lately the amount of grasslands and pastures has drastically declined all over Europe. In Finland, the area of semi-natural biotopes has decreased to 1% of what it had …

Grass And Forage Plant Improvement In The Tropics And Sub-Tropics, Liana Jank, C. B. Do Valle, Rosangela M. S. Resende

IGC Proceedings (1977-2023)

1. The majority of tropical and subtropical forage grass genera and/or species have not yet been collected, or need further collection to be representative of their natural distribution.
2. New biotechnological techniques will only result in the release of superior forage cultivars if supported by strong breeding programs.
3. More funding and investment in the formation of strong public research teams in forage conservation and improvement are needed to guarantee the sustainability of tropical and subtropical pasture-based livestock systems in the future.
4. The creation of a permanent international working group on tropical and subtropical forages is essential to assist the International Plant Genetic …

Nationwide Assessment Of Leadership Development For Graduate Students In The Agricultural Plant Sciences, Karen Ferreira Da Silva, Ella Burnham, Joe Louis, Douglas Golick, Sydney E. Everhart

Department of Plant Pathology: Faculty Publications

Leadership development is a universally important goal across the agricultural plant science disciplines. Although previous studies have identified a need for leadership skills, less is known about leadership skill development in graduate programs. To address this, we constructed a mixed-method study to identify the most significant graduate school leadership experiences of scientists in the agricultural plant science disciplines. The survey was deployed to 6,728 people in the U.S. and received 1,086 responses (16.1% response rate). The majority of respondents reported that they were from one of the major agricultural states and employed at one of the agricultural plant science related …

Plant Viruses Of Agricultural Importance: Current And Future Perspectives Of Virus Disease Management Strategies, Satyanarayana Tatineni, Gary Hein

Department of Plant Pathology: Faculty Publications

Plant viruses cause significant losses in agricultural crops worldwide, affecting the yield and quality of agricultural products. The emergence of novel viruses or variants through genetic evolution and spillover from reservoir host species, changes in agricultural practices, mixed infections with disease synergism, and impacts from global warming pose continuous challenges for the management of epidemics resulting from emerging plant virus diseases. This review describes some of the most devastating virus diseases plus select virus diseases with regional importance in agriculturally important crops that have caused significant yield losses. The lack of curative measures for plant virus infections prompts the use …

Natural Transmission Of Grapevine Vein Clearing Virus, Matthew Manu

Graduate Theses/Dissertations

More than 60 million tons of grapes are produced annually in the world, making them one of the most widely grown fruit crops. Despite grapes’ economic and health benefits, biotic stressors, such as viruses, cause significant loss to the grape and wine industry. One such virus is grapevine vein clearing virus (GVCV) which seriously threatens grape cultivation in the Midwest region of the United States. This virus has caused the removal of seven commercial vineyards since its discovery in 2004. About 34% of Ampelopsis cordata wild vines are infected with GVCV and serve as a primary inoculum for the spread …

Distribution Patterns Of Allorhizobium Vitis In Missouri Vineyards And Non-Vineyard Soils, Jacquelyn M. Wray

Graduate Theses/Dissertations

Crown gall disease causes significant economic loss to the grape and wine industry. Preventive strategies are most effective for mitigating the loss of grapevines in vineyards, as there is no known cure for this disease. The bacterium Allorhizobium vitis carrying a tumor-inducing (Ti) plasmid is the causative agent. A. vitis bacteria live systemically in the grapevine before causing visible symptoms and can survive in residual plant tissues and soil for more than two years. Diagnostic methods have been developed to detect A. vitis bacteria in grapevines and soil. However, more reliable, specific, and high-throughput diagnostics are still needed for screening …

Exploring The Effects Of Environmental Factors On Rice Blast Disease, April Ellen Lamb

Theses and Dissertations--Plant Pathology

Rice blast disease, caused by the ascomycete fungus Magnaporthe oryzae, occurs in over 85 countries and results in an annual crop loss of 10-30%, a corresponding nutrient value of meals for 60 million people. As a result, it is listed as a critical plant disease by the United Nations. Understanding factors affecting disease severity is of critical concern for food security. M. oryzae has been used as a model system for studying effector-triggered immunity (ETI) by understanding that ETI is primarily a plant response. M. oryzae has been used as a model to study fungal pathogenicity, host specificity, genome …

Opportunities And Challenges In Augmenting Honey Bee Forage Resources With Pasture Legumes In Southern Australia, M. Kratz, M. Brown, M. T. Newell, R. C. Hayes

IGC Proceedings (1977-2023)

More than 80% of Australian honey is produced from native tree and shrub species. However, with increasing demands on public lands along with production risks posed by drought, floods and wildfires, there is a need to identify alternative forage resources to augment Australian honey production. With over 30 pasture legumes now available for agriculture in southern Australia, opportunity exists to increase the utilisation of some species with co-benefits to multiple production industries. However, there is little understanding of the potential value of most pasture legumes for honey production, and side by side comparisons are complicated by factors such as differences …

Data Curation For Modeling Tall Fescue Biomass Dynamics With Dssat-Csm, M. B. Hanson, P. D. Alderman, T. J. Butler, A. Caldeira Rocateli

IGC Proceedings (1977-2023)

While models for predicting forage production are available to aid management decisions for some forage crops, there is limited research for a yield model designed specifically for tall fescue (Schedonorus arundinaceus). Therefore, our objective was to adapt an existing perennial forage model, the Decision Support System for Agrotechnology Transfer Cropping Systems Model (DSSAT-CSM) for predicting forage biomass of tall fescue in the southern Great Plains. To evaluate model performance, there must first be a high level of data manipulation and cleaning. In this project, a cohesive dataset combining biomass, weather, soil, and management data were structured into DSSAT …

Can Changing Breeding Structure Serve As A Climate Adaptation Strategy? Evidence From A Comparative Study Of China And Mongolia, Y. Zhang, Z. Huang, J. Wang, Y. Huang, T. Hao, G. Xu

IGC Proceedings (1977-2023)

Under the influence of climate change, the vulnerability of grassland ecosystems in the Mongolian Plateau has increased. Correspondingly, herdsmen need to adopt more livelihood adaptation strategies to cope with changes in climate and grassland environment. The purpose of this study is to analyze the impact of breeding structure on grassland quality in Mongolian plateau. We select 20 border provinces/banners of Mongolia and Inner Mongolia Autonomous Region for research, and combined statistical data with remote sensing data of 2007-2016. The Normalized Difference Vegetation Index (NDVI) is used to quantify the grassland vegetation quality. Results show that there are differences in livestock …

Fusarium Head Blight Resistance Assessment In Barley, Tasneem Fathima

Electronic Theses and Dissertations

Fusarium head blight (FHB), commonly called scab is the most devastating disease of wheat and barley caused by the ascomycete fungus, Fusarium graminearum. FHB affects both the quality and quantity of cereal grains affecting the supply chain of the food and feed industry and the marketability of the produce. Barley (Hordeum vulgare L.) is among the several crop species most vulnerable to FHB infection. An estimated 25% of Spring barley grain production in the United States is used to make malted beverages such as beer. Malting barley is a relatively high-value crop with high demands regarding grain quality. FHB directly …

The Effects Of Residue Amounts And Variety Selection On The Development Of Wheat Fungal Pathogens In South Dakota, Abrielle Tembreull

Electronic Theses and Dissertations

Roughly 50% of South Dakota cropland is under the practice of no-till, with large increases in acres of no-till in the last 20 or so years. No-till is beneficial for Great Plains states, such as South Dakota, as soil residues are withheld. Residues are shown to increase soil health through retention of moisture and increase of microorganisms, but residues can serve as a source of inoculum for fungal pathogens that can overwinter on them. As wheat is one of the most important food crops in the world, it is important to protect this vital crop from diseases. Diseases of wheat …

Biological Control Of Bacterial Leaf Streak Of Wheat Using Antagonistic Rhizobacteria, Ashley Frederickson

Electronic Theses and Dissertations

Wheat (Triticum aestivum L.) is one of the world’s most valuable crops, and the primary food grain produced in the United States. A major disease in wheat production is Bacterial Leaf Streak (BLS) caused by the gram-negative bacterium Xanthomonas translucens pv. undulosa (Xtu). Very few management strategies are available to growers to manage this disease, as common chemicals do not provide adequate control. A number of studies have been conducted on biological control using Rhizospheric bacteria for the control of various plant diseases, but limited data is available on the efficacy of biological control using Rhizospheric bacteria for controlling Bacterial …

Unveiling Race Diversity And Fungicide Sensitivity Profiles Of Pyrenophora Tritici Repentis Populations In South Dakota Collected From 2021-2023, Jaswinder Kaur

Electronic Theses and Dissertations

Tan spot, a foliar disease of wheat caused by the ascomycetes fungus Pyrenophora tritici repentis (Ptr), poses a significant threat to wheat crops globally. The disease gained economic importance in the late 1970s due to shifts in farming practices, such as minimal tillage and planting on crop residues, providing favorable conditions for the pathogen to overwinter and cause infections. Ptr is classified into eight races based on the production of necrotrophic effectors—Ptr ToxA (necrosis-inducing), Ptr ToxB, and Ptr ToxC (chlorosis-inducing on respective susceptible and sensitive cultivars)—resulting in distinct symptoms on susceptible wheat differentials. The inverse gene-for-gene hypothesis of Ptr suggests …

Investigation Of Fungal Pathogens And Woodboring Beetles Of Sugarbush Stands In The Central Appalachian Region, Molly A. Sherlock

Graduate Theses, Dissertations, and Problem Reports (ETD)

The production of maple syrup is a valuable source of income and cultural identity for many rural communities throughout the central Appalachian region. Regardless, maple syrup producers face difficulties maintaining the health and productivity
of their stands due to various impacts of climate change, which have given rise to extreme weather events that exacerbate damage caused by pests and diseases. To ensure the long-term sustainability of the maple syrup industry, it is crucial to obtain a comprehensive understanding of the current biotic threats within the region, particularly woodboring insects and fungal pathogens. However, insufficient information exists regarding the community assemblages …

Establishment Of The Invasive Cactus Moth, Cactoblastis Cactorum (Berg) (Lepidoptera: Pyralidae) In Pakistan: A Potential Threat To Cultivated, Ornamental And Wild Opuntia Spp. (Cactaceae), Muhammad Ather Rafi, Harry Pavulaan, Muhammad Islam, Muhammad Ashfaq, Haseeb Kamran, Walija Fayaz, Gul Naz Parveen, Riffat Sultana, Ahmad Zia, Waqar Ahmed, Qudrat Ullah, Muhammad Qasim, Falak Naz, Nazeer Ahmed, Muhammad Tariq Khan, Muhammad Saeed, Jalal Hayat Khan

The Taxonomic Report of the International Lepidoptera Survey

Subsequent to the significant accomplishment of biological control of Opuntia weeds in Australia, the larvae of the cactus moth, Cactoblastis cactorum (native to parts of South America), were released in many countries for the biological control of native Opuntia species (Simmonds and Bennett, 1966). Inauspiciously, larvae were also released in the Caribbean, where the moth spread naturally and by the human support all over the region (García-Turudi et al., 1971). Its enhanced dissemination rate and the biological potential for invasiveness, suggests that the cactus moth is likely to become an invasive pest of Opuntia in the Southeast United States, Mexico, …

6k1, Nia-Vpg, Nia-Pro, And Cp Ofwheat Streak Mosaic Virus Are Collective Determinants Of Wheat Streak Mosaic Disease In Wheat, Satyanarayana Tatineni, Jeffrey Alexander, Haritha Nunna

Department of Plant Pathology: Faculty Publications

Wheat streak mosaic virus (WSMV; genus Tritimovirus, family Potyviridae) is the causal agent of the most economically important wheat streak mosaic disease of wheat (Triticum aestivum) in the Great Plains region of theUnited States.WSMVdeterminants responsible forwheat streak mosaic disease in wheat are unknown. Triticum mosaic virus (TriMV), a wheatinfecting virus,was used as an expression vector for the transient expression of each of the WSMV-encoded cistrons in wheat. WSMV-encoded 6K1, NIa-VPg, NIa-Pro, and CP cistrons in TriMV elicited symptoms specific to different stages of wheat streak mosaic disease without significantly affecting the genomic RNA accumulation. WSMV 6K1 …

Population Genomics Provide Insights Into The Global Genetic Structure Of Colletotrichum Graminicola, The Causal Agent Of Maize Anthracnose, Flávia Rogério, Riccardo Baroncelli, Francisco Borja Cuevas-Fernández, Sioly Becerra, Joanne Crouch, Wagner Bettiol, M. Andrea Azcárate-Peril, Martha Malapi-Wight, Veronique Ortega, Javier Betran, Albert Tenuta, José S. Dambolena, Paul D. Esker, Pedro Revilla, Tamra A. Jackson-Ziems, Jürg Hiltbrunner, Gary Munkvold, Ivica Buhiniček, José L. Vicente-Villardón, Serenella A. Sukno, Michael R. Thon

Department of Plant Pathology: Faculty Publications

Understanding the genetic diversity and mechanisms underlying genetic variation in pathogen populations is crucial to the development of effective control strategies. We investigated the genetic diversity and reproductive biology of Colletotrichum graminicola isolates which infect maize by sequencing the genomes of 108 isolates collected from 14 countries using restriction site-associated DNA sequencing (RAD-seq) and wholegenome sequencing (WGS). Clustering analyses based on single-nucleotide polymorphisms revealed three genetic groups delimited by continental origin, compatible with short-dispersal of the pathogen and geographic subdivision. Intra- and intercontinental migration was observed between Europe and South America, likely associated with the movement of contaminated germplasm. Low …

6k1, Nia-Vpg, Nia-Pro, And Cp Ofwheat Streak Mosaic Virus Are Collective Determinants Of Wheat Streak Mosaic Disease In Wheat, Satyanarayana Tatineni, Jeffrey Alexander, Haritha Nunna

Department of Plant Pathology: Faculty Publications

Wheat streak mosaic virus (WSMV; genus Tritimovirus, family Potyviridae) is the causal agent of the most economically important wheat streak mosaic disease of wheat (Triticum aestivum) in the Great Plains region of theUnited States.WSMVdeterminants responsible forwheat streak mosaic disease in wheat are unknown. Triticum mosaic virus (TriMV), a wheatinfecting virus,was used as an expression vector for the transient expression of each of the WSMV-encoded cistrons in wheat. WSMV-encoded 6K1, NIa-VPg, NIa-Pro, and CP cistrons in TriMV elicited symptoms specific to different stages of wheat streak mosaic disease without significantly affecting the genomic RNA accumulation. WSMV 6K1 …

Dynamics Of Redox-Driven Molecular Processes In Local And Systemic Plant Immunity, Philip Berg

Theses and Dissertations

The work here presents two main parts. In the first part, chapters 1 – 3 focus on dynamical systems modeling in plant immunity, whereas chapters 4 – 6 describe contributions to computational modeling and analysis of proteomics and genomics data. Chapter 1 investigates dynamical and biochemical patterns of reversibly oxidized cysteines (RevOxCys) during effector-triggered immunity (ETI) in Arabidopsis, examines the regulatory patterns associated with Arabidopsis thimet oligopeptidase 1 and 2’s (TOP1 and TOP2), roles in the RevOxCys events during ETI, and analyzes the redox phenotype of the top1top2 mutant. The second chapter investigates the peptidome dynamics during ETI …

The Emerging Value Of The Viroid Model In Understanding Plant Responses To Foreign Rnas, Junfei Ma

Theses and Dissertations

RNAs play essential roles in various biological processes. Mounting evidence has demonstrated that RNA subcellular localization and intercellular trafficking govern their functions in coordinating plant growth at the organismal level. Beyond that, plants constantly encounter foreign RNAs (i.e., RNAs from pathogens including viruses and viroids). The subcellular localizations of RNAs are crucial for their function. While numerous types of RNAs (i.e., mRNAs, small RNAs, rRNAs, tRNAs, and long noncoding RNAs) have been found to traffic in a non-cell-autonomous fashion within plants, the underlying regulatory mechanism remains unclear. Viroids are single-stranded circular noncoding RNAs, which entirely rely …

Demonstration Farm Provides Educational Opportunity For Ipm, Nick Volesky, Mair Murray

Outcomes and Impact Quarterly

The mission of USU Extension’s Integrated Pest Management (IPM) program is to increase the use of sustainable pest management practices within urban and rural landscapes to provide economic, human, and environmental health in Utah. In the spring of 2022, the IPM program established a vegetable farm to test and demonstrate IPM practices. The farm served as an experiential learning classroom for almost 50 farmers and home gardeners.

Evaluation Of Biological And Chemical Seed Treatments For Management Of Rice Diseases, Sherif Adam Sharfadine

Graduate Theses and Dissertations

Rice is the primary staple for more than half of the global population and is the second most important cereal worldwide. In the US, rice is primarily grown in the southern states, with Arkansas leading production and responsible for 47% of the total rice production in the country. Diseases cause significant yield losses in rice. Sheath blight, rice blast and bacterial panicle blight are the main diseases in rice and cause significant yield losses. Sheath blight alone could cause up 50% yield loss in heavily damaged fields with highly susceptible cultivars. Additionally, rice seed and seedling diseases primarily caused by …

In Vitro Rooting Techniques In Prunus Spp. For Propagation And Disease Screening For Armillaria Root Rot (Arr) Resistance, John Lawson

All Theses

Prunus is a genus widely cultivated to produce edible fruit including almond (P. amygdalus), peach (P. persica (L.) Batsch), cherries (P. avium and P. cerasus), among others. The cultivation of Prunus is economically important for several regions of the United States and relies on appropriate cultivars and rootstocks that are adapted to a growing region. Encroaching plant pathogens are forcing breeders to use sexually compatible germplasm from related species for introgression of novel alleles that confer tolerance or resistance. This is especially true in the rootstock breeding where interspecific hybridization is often used …

Addressing Meloidogyne Enterolobii Spread In The Sweetpotato Industry: Development Of A High Throughput Survey Detection Method For Root-Knot Nematodes And Quantification Of M. Enterolobii Damage On Storage Roots In Long-Term Assays, Julianna Culbreath

All Theses

Meloidogyne enterolobii is an aggressive root-knot nematode (RKN) species that has emerged as a significant pathogen of sweetpotato in the Southeastern US. Meloidogyne enterolobii is spread through the movement of infected ‘seed’ sweetpotatoes used for propagation, and the RKN resistance in commercial sweetpotato cultivars has proven ineffective against this nematode. This has prompted regulatory agencies to impose quarantines on regions infected with M. enterolobii. Sweetpotato storage roots can be rendered unmarketable due to M. enterolobii infection, resulting in potential overall yield loss. Visual detection of RKN in sweetpotato can be unreliable, and further distinguishing M. enterolobii from other RKN species …

Understanding The Influence Of Excessive Fertilization And Water Relations On Peach (Prunus Persica (L.) Batsch) Skin Bronzing, Sydney Lykins

All Theses

This project evaluated possible causes of peach skin bronzing, a brown-blotchy skin discoloration on mid to late-season peaches that causes drastic decreases to grower incomes in the Southeastern U.S. It is known that there is no bacterial, insectile, viral, or fungal cause of bronzing; thus, these studies focused on potential nutrient imbalances within the peach. On the ‘PF23’ variety, factors of irrigation, potassium fertilization, and transpiration-inhibiting sprays were tested to see the various effects on the incidence and severity of bronzing. The hypothesis was that excessive irrigation and excessive soil potassium concentrations would induce a higher incidence and severity of …

Micronutrient Concentration Effects On Lettuce Growth And Susceptibility To Pythium, Kalyn M. Helms

Graduate Theses and Dissertations

In hydroponic production waterborne pathogens such as Pythium are ubiquitous and continually threaten a wide range of Controlled Environment Agriculture (CEA) crops in hydroponic production, including but not limited to: lettuce, spinach, basil, arugula, cucumber, tomato, sweet pepper, roses, chrysanthemums, and cannabis (Sutton et al., 2006; Gull, 2002; McGehee and Raudales, 2021; Gillespie, 2020). Despite extensive sanitation measures, disease control in hydroponics is fallible and requires constant surveillance and management to minimize outbreaks (Sutton et al., 2006). A potential disease suppression strategy is to increase micronutrient concentrations within hydroponic systems to naturally strengthen plant defenses against pathogens such as Pythium. …