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2019

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Articles 211 - 240 of 295

Full-Text Articles in Plant Pathology

Improved Drought Stress Tolerance Of White Clover Through Hybridisation With Trifolium Uniflorum L., Shirley N. Nichols, Rainer W. Hofmann, Isabelle M. Verry Nov 2019

Improved Drought Stress Tolerance Of White Clover Through Hybridisation With Trifolium Uniflorum L., Shirley N. Nichols, Rainer W. Hofmann, Isabelle M. Verry

IGC Proceedings (1977-2023)

The objective of this study was to determine the effect of hybridisation with Trifolium uniflorum L. on drought resistance of Trifolium repens L. (white clover). Shoot dry weight of backcross 1 (BC1) hybrids was reduced less by water stress than for backcross 2 (BC2) hybrids and white clover, as were key morphological traits such as leaf area. Under water stress, important differences for the BC1 generation compared to white clover also included lower senescence, higher stolon density, increased root dry weight, and a higher maximum nodal root diameter. Drought decreased the net photosynthetic rate by up to 48% in BC2 …


Designing Resilient And Sustainable Grasslands For A Drier Future: Adaptive Strategies, Functional Traits And Biotic Interactions, Florence Volaire, Karim Barkaoui, Mark Norton Nov 2019

Designing Resilient And Sustainable Grasslands For A Drier Future: Adaptive Strategies, Functional Traits And Biotic Interactions, Florence Volaire, Karim Barkaoui, Mark Norton

IGC Proceedings (1977-2023)

In many regions of the world, such as Southern Europe and most Mediterranean areas, the frequency and magnitude of droughts and heat waves are expected to increase under global warming and will challenge the sustainability of both native and sown grasslands. To analyze the adaptive strategies of species, genotypes and cultivars, we aim both: (1) to understand the composition and functioning of natural grasslands; and (2) to propose ideotypes of cultivars and optimal composition for mixtures of species/genotypes under water deficit and high temperatures. This review presents a conceptual framework to analyze adaptive responses of perennial herbaceous species, starting from …


Australian Grasslands Research At The Crossroads, Alan Robson Nov 2019

Australian Grasslands Research At The Crossroads, Alan Robson

IGC Proceedings (1977-2023)

Grasslands research in Australia is at a crossroad. There are several difficulties. First, the decline of sheep production and dairying within Australia and increased cropping has focused attention on crop research rather than pasture research. Second, enrolments in agricultural and related education have declined, and graduate numbers are insufficient to meet demand for expertise. Third, there has been a move towards specialisation in research and there are relatively few generalist agricultural scientists able to integrate research results into agricultural ecosystems. There remain very many challenges. Adapting grassland production to minimize the emission of carbon dioxide and methane is a major …


International R D & E Investment: Revitalising The Skill Base In Grassland Research And Practice, Ralph Von Kaufmann Nov 2019

International R D & E Investment: Revitalising The Skill Base In Grassland Research And Practice, Ralph Von Kaufmann

IGC Proceedings (1977-2023)

Grasslands make up about 40.5% of the world’s land surface, and almost everywhere they make vital contributions to food supplies, livelihoods, watersheds, conservation of biodiversity and to ameliorating climate change through carbon sequestration. However, grasslands are under-represented in discussions on food security and livelihoods. Despite large investments in building human capacity, improving production systems and in research, grasslands are continuing to degrade and there is no let-up in sight for the consequent strife, famines and conflicts among the pastoral and other communities that depend on them. This review of grassland issues identified many critical skills that are lacking but it …


Drivers Of Change For Grassland And Forage Systems: A Case Study Of China, Yingjun Zhang, L. Z. Zhang, M. L. Wang, X. L. Li, Q. C. Yang, J. Hanson, M. A. Jorge Nov 2019

Drivers Of Change For Grassland And Forage Systems: A Case Study Of China, Yingjun Zhang, L. Z. Zhang, M. L. Wang, X. L. Li, Q. C. Yang, J. Hanson, M. A. Jorge

IGC Proceedings (1977-2023)

Grassland and forage systems have changed dramatically across the world. This paper describes some of the key drivers of change of grassland and forage systems using examples from China as a case study. The key drivers of change for grassland and forage systems include political, economic, social, technical and environmental factors and their impact on changes in grasslands ecosystems in China is discussed. There are interactions among the drivers and their impact is similar in many developing countries.


Legumes, Livestock And Livelihoods In The Australian Mixed Farming System, E. C. Wolfe Nov 2019

Legumes, Livestock And Livelihoods In The Australian Mixed Farming System, E. C. Wolfe

IGC Proceedings (1977-2023)

This Howard Oration describes the pathway that I have taken towards my specialisation in ‘big picture’ agriculture. A simple protocol is presented for the analysis of agricultural systems by using descriptive or quantitative indicators of five system properties: productivity, sustainability, profitability, social wellbeing and political acceptability. These properties are further illustrated by considering four important issues in the Australian sheep-wheat belt, a distinctive world food production system. The issues are the supply of and demand for legume nitrogen for crops, reconciling agricultural and natural resource objectives, the low profitability of farms in relation to production and marketing risks, and the …


Does Intensification Of Grassland And Forage Use Lead To Efficient, Profitable And Sustainable Ecosystems?, Oene Oenema, Cecile De Klein, Marta Alfaro Nov 2019

Does Intensification Of Grassland And Forage Use Lead To Efficient, Profitable And Sustainable Ecosystems?, Oene Oenema, Cecile De Klein, Marta Alfaro

IGC Proceedings (1977-2023)

The increasing demand for safe and nutritional dairy and beef products in our globalizing world, together with the needs to increase resource use efficiency and to protect biodiversity, provide strong incentives for intensification of grassland and forage use. This paper addresses the question in the title. Firstly, we present some notions about ‘intensification of agricultural production’. Secondly, we discuss the intensification of grassland-based dairy production in The Netherlands (NL), Chile and New Zealand (NZ). Finally, we arrive at some conclusions. External driving forces and ‘the law of the optimum’ provide strong incentives for intensification, i.e., for increasing the output per …


New Frontiers And Perspectives In Grassland Technology, Jürgen Schellberg, E. Verbruggen Nov 2019

New Frontiers And Perspectives In Grassland Technology, Jürgen Schellberg, E. Verbruggen

IGC Proceedings (1977-2023)

Grassland scientists and farmers are increasingly faced with emerging new technologies and in-formation systems that have been primarily developed by engineering sciences in particular: precision agriculture, remote sensing, geographic localization and biotechnology. Whether the implementation of any of these technologies may be beneficial in economic and ecological respect is a challenging judgment call, especially for those who have to carry over that decision on their farm. Compared to arable land, new technologies have been applied on grassland only partially and with some delay. However, as we will demonstrate, there is place for a successful implementation of new technologies in various …


Diversity, Trends, Opportunities And Challenges In Australian Grasslands–Meeting The Sustainability And Productivity Imperatives Of The Future?, Lindsay W. Bell, Richard C. Hayes, Keith G. Pembleton, Cathy M. Waters Nov 2019

Diversity, Trends, Opportunities And Challenges In Australian Grasslands–Meeting The Sustainability And Productivity Imperatives Of The Future?, Lindsay W. Bell, Richard C. Hayes, Keith G. Pembleton, Cathy M. Waters

IGC Proceedings (1977-2023)

Grassland production systems contribute 40% to Australia’s gross agricultural production value and utilise over 50% of its land area. Across this area a broad diversity of systems exist, but these can be broadly classified into four main production systems: 1. Pastoral grazing of mainly cattle at low intensity (i.e. < 0.4 DSE/ha) on relatively unimproved native rangelands in the arid and semi-arid regions of northern and central Australia; 2. Crop-livestock systems in the semi-arid zone where livestock graze a mixture of pastures and crops which are often integrated; 3. High rainfall permanent pasture zone in the coastal hinterland and highlands and; 4. Dairy systems covering a broad range of environments and production intensities. A notable trend across these systems has been the replacement of wool sheep with beef cattle or meat sheep breeds, which has been driven by low wool prices. Although there is evidence that most of these systems have lifted production efficiencies over the past 30 years, total factor productivity growth has failed to match the decline in terms of trade. This has renewed attention on how research and development can help increase productivity. In addition, these industries are facing increasing scrutiny to improve their environmental performance and develop sustainable production practices. We propose several areas in which grasslands research and development might help provide gains in system productivity and sustainability. In particular, pasture productivity might be improved by filling gaps in the array of pastures available either through exploring new species or improving the adaptation and agronomic characteristics of species currently sown. Meanwhile there is a need to maintain efforts to overcome persistent and emerging constraints to pasture productivity. Improving livestock forage feed systems and more precise and lower cost management of grasslands would translate into improved utilisation and conversion of forage produced into livestock products. There is significant scope to capture value from the ecological services grasslands provide and mitigate greenhouse gas emissions from livestock production. Multi-purpose grasslands provide not only grazing for livestock but produce other food products such as grain which may also have potential to integrate livestock with cropping. However, reduced human research capacity in pasture science will challenge our ability to realise these potential opportunities unless efforts are made to attract and support a new generation of pasture scientists.


Managing Grassland Systems In A Changing Climate: The Search For Practical Solutions, Jean-François Soussana, Luis Gustavo Barioni, Tamara Ben Ari, Rich Conant, Pierre Gerber, Petr Havlik, Alexandre Ickowicz, Mark Howden Nov 2019

Managing Grassland Systems In A Changing Climate: The Search For Practical Solutions, Jean-François Soussana, Luis Gustavo Barioni, Tamara Ben Ari, Rich Conant, Pierre Gerber, Petr Havlik, Alexandre Ickowicz, Mark Howden

IGC Proceedings (1977-2023)

By the end of the XXIst century, a global temperature rise between 1.5 and 4°C compared to 1980-1999 and CO2 concentrations in the range 550-900 ppm are expected, together with an increased frequency of extreme climatic events (heat waves, droughts, and heavy rain) that is likely to negatively affect grassland production and livestock systems in a number of world regions. Grassland management has a large potential to mitigate livestock greenhouse gas emissions at a low (or even negative) cost, by combining a moderate intensification, the restoration of degraded pastures and the development of silvo-pastoral systems. Climate change vulnerability …


Feeding The World In 2050: Trade-Offs, Synergies And Tough Choices For The Livestock Sector, Jimmy Smith, Shirley Tarawali, Delia Grace, Keith Sones Nov 2019

Feeding The World In 2050: Trade-Offs, Synergies And Tough Choices For The Livestock Sector, Jimmy Smith, Shirley Tarawali, Delia Grace, Keith Sones

IGC Proceedings (1977-2023)

Feeding the World in 2050 is a major challenge at the forefront of the global development agenda. The importance of agriculture in addressing this challenge has re-emerged in recent years as food security issues are considered in a more holistic manner. The role of livestock as part of the solution is, however, often not considered. This article presents a brief overview of the global food security challenge, and considers the increased focus on holistic food systems. It contends that animal agriculture is relevant to this complex, multifaceted and dynamic global challenge. However, if livestock-based solutions are to become a reality …


Front Matter [22nd International Grassland Congress Proceedings], Organizing Committee, International Grassland Congress Nov 2019

Front Matter [22nd International Grassland Congress Proceedings], Organizing Committee, International Grassland Congress

IGC Proceedings (1977-2023)

No abstract provided.


Glycerol-3-Phosphate Mediates Rhizobia-Induced Systemic Signaling In Soybean, M. B. Shine, Qing-Ming Gao, R. V. Chowda-Reddy, Asheesh K. Singh, Pradeep Kachroo, Aardra Kachroo Nov 2019

Glycerol-3-Phosphate Mediates Rhizobia-Induced Systemic Signaling In Soybean, M. B. Shine, Qing-Ming Gao, R. V. Chowda-Reddy, Asheesh K. Singh, Pradeep Kachroo, Aardra Kachroo

Plant Pathology Faculty Publications

Glycerol-3-phosphate (G3P) is a well-known mobile regulator of systemic acquired resistance (SAR), which provides broad spectrum systemic immunity in response to localized foliar pathogenic infections. We show that G3P-derived foliar immunity is also activated in response to genetically-regulated incompatible interactions with nitrogen-fixing bacteria. Using gene knock-down we show that G3P is essential for strain-specific exclusion of non-desirable root-nodulating bacteria and the associated foliar pathogen immunity in soybean. Grafting studies show that while recognition of rhizobium incompatibility is root driven, bacterial exclusion requires G3P biosynthesis in the shoot. Biochemical analyses support shoot-to-root transport of G3P during incompatible rhizobia interaction. We describe …


Transgenic Control Of Aflatoxin Contamination In Maize Through Host-Induced Gene Silencing Targeting Aspergillus Flavus Genes Encoding Polygalacturonase (P2c) And Versicolorin Dehydrogenase (Aflm), Yenjit Raruang Nov 2019

Transgenic Control Of Aflatoxin Contamination In Maize Through Host-Induced Gene Silencing Targeting Aspergillus Flavus Genes Encoding Polygalacturonase (P2c) And Versicolorin Dehydrogenase (Aflm), Yenjit Raruang

LSU Doctoral Dissertations

Maize (Zea mays L.) is susceptible to Aspergillus flavus infection and subsequent contamination with aflatoxins, the most potent naturally produced carcinogenic secondary metabolites. Here, the A. flavus gene aflM encoding the versicolorin dehydrogenase in aflatoxin biosynthesis and the p2c gene encoding the polygalacturonase that is involved in infection were selected as targets for suppression through host induced gene silencing (HIGS). A HIGS vector targeting these genes was constructed and introduced into immature B104 maize embryos. Thirteen out of fifteen p2c transformation events and six out of seven aflM events were confirmed positive by PCR. Kernels containing the p2c gene …


Exploitation Of Wastelands For Fodder Production And Agroforestry, Gurbachan Singh Oct 2019

Exploitation Of Wastelands For Fodder Production And Agroforestry, Gurbachan Singh

IGC Proceedings (1977-2023)

Natural resources degradation for agricultural production and environmental protection has been a matter of concern for future food, nutrition, environment and livelihood security. As per current estimates, 120.7 million hectare (mha) is under degraded or wastelands. These lands provide ample opportunity for growing fodder trees and grasses to bridge the gap between demand and supply of green and dry fodder.Several species of fodder trees and grasses have been identified and their agro-techniques standardized for raising in different categories of wastelands such as affected by soil and wind erosion, salinity, acidity and mining etc. A brief account of such plants is …


Parameter Estimation Within An Sir Model Of Chestnut Blight In North America, Anita Davelos Baines, Hope B. Anderson, John S. Mcalister, Robert F. Allen Oct 2019

Parameter Estimation Within An Sir Model Of Chestnut Blight In North America, Anita Davelos Baines, Hope B. Anderson, John S. Mcalister, Robert F. Allen

Annual Symposium on Biomathematics and Ecology Education and Research

No abstract provided.


Sir Modeling Of American Chestnut Blight, Tatum Rask Oct 2019

Sir Modeling Of American Chestnut Blight, Tatum Rask

Annual Symposium on Biomathematics and Ecology Education and Research

No abstract provided.


Coffee Is Not Forever : A Global History Of The Coffee Leaf Rust, Stuart Mccook Oct 2019

Coffee Is Not Forever : A Global History Of The Coffee Leaf Rust, Stuart Mccook

Ohio University Press Open Access Books

The global coffee industry, which fuels the livelihoods of farmers, entrepreneurs, and consumers around the world, rests on fragile ecological foundations. In Coffee Is Not Forever, Stuart McCook explores the transnational story of this essential crop through a history of one of its most devastating diseases, the coffee leaf rust. He deftly synthesizes agricultural, social, and economic histories with plant genetics and plant pathology to investigate the increasing interdependence of the world’s coffee-producing zones. In the process, he illuminates the progress and prognosis of the challenges—especially climate change—that pose an existential threat to a crop that global consumers often take …


Transcriptome Divergence During Leaf Development In Two Contrasting Switchgrass (Panicum Virgatum L.) Cultivars, Nathan A. Palmer, R. V. Chowda-Reddy, Anthony A. Muhle, Satyanarayana Tatineni, Gary Y. Yuen, Serge J. Edme, Robert B. Mitchell, Gautam Sarath Sep 2019

Transcriptome Divergence During Leaf Development In Two Contrasting Switchgrass (Panicum Virgatum L.) Cultivars, Nathan A. Palmer, R. V. Chowda-Reddy, Anthony A. Muhle, Satyanarayana Tatineni, Gary Y. Yuen, Serge J. Edme, Robert B. Mitchell, Gautam Sarath

Department of Plant Pathology: Faculty Publications

The genetics and responses to biotic stressors of tetraploid switchgrass (Panicum virgatum L.) lowland cultivar ‘Kanlow’ and upland cultivar Summer are distinct and can be exploited for trait improvement. In general, there is a paucity of data on the basal differences in transcription across tissue developmental times for switchgrass cultivars. Here, the changes in basal and temporal expression of genes related to leaf functions were evaluated for greenhouse grown ‘Kanlow’, and ‘Summer’ plants. Three biological replicates of the 4th leaf pooled from 15 plants per replicate were harvested at regular intervals beginning from leaf emergence through senescence. Increases and decreases …


Neonicotinoid Seed Treatments Of Soybean Provide Negligible Benefits To Us Farmers, Spyridon Mourtzinis, Christian H. Krupke, Paul D. Esker, Adam J. Varenhorst, Nicholas J. Arneson, Carl A. Bradley, Adam M. Byrne, Martin I. Chilvers, Loren Giesler, Ames Herbert, Yuba R. Kandel, Maciej J. Kazula, Catherine Hunt, Laura E. Lindsey, Sean Malone, Daren S. Mueller, Seth Naeve, Emerson Nafziger, Dominic D. Reisig, William J. Ross, Devon R. Rossman, Sally Taylor, Shawn P. Conley Sep 2019

Neonicotinoid Seed Treatments Of Soybean Provide Negligible Benefits To Us Farmers, Spyridon Mourtzinis, Christian H. Krupke, Paul D. Esker, Adam J. Varenhorst, Nicholas J. Arneson, Carl A. Bradley, Adam M. Byrne, Martin I. Chilvers, Loren Giesler, Ames Herbert, Yuba R. Kandel, Maciej J. Kazula, Catherine Hunt, Laura E. Lindsey, Sean Malone, Daren S. Mueller, Seth Naeve, Emerson Nafziger, Dominic D. Reisig, William J. Ross, Devon R. Rossman, Sally Taylor, Shawn P. Conley

Department of Plant Pathology: Faculty Publications

Neonicotinoids are the most widely used insecticides worldwide and are typically deployed as seed treatments (hereafter NST) in many grain and oilseed crops, including soybeans. However, there is a surprising dearth of information regarding NST effectiveness in increasing soybean seed yield, and most published data suggest weak, or inconsistent yield benefit. The US is the key soybean-producing nation worldwide and this work includes soybean yield data from 194 randomized and replicated field studies conducted specifically to evaluate the effect of NSTs on soybean seed yield at sites within 14 states from 2006 through 2017. Here we show that across the …


Arkansas Wheat Cultivar Performance Tests 2018-2019, R. E. Mason, R. G. Miller, D. E. Moon, J. P. Kelley Sep 2019

Arkansas Wheat Cultivar Performance Tests 2018-2019, R. E. Mason, R. G. Miller, D. E. Moon, J. P. Kelley

Arkansas Agricultural Experiment Station Research Series

Wheat cultivar performance tests are conducted each year in Ark- ansas by the University of Arkansas System Division of Agriculture’s Arkansas Agricultural Experiment Station, Department of Crop, Soil and Environmental Sciences. The tests provide information to companies developing cultivars and marketing seed within the state and aid the Arkansas Cooperative Extension Service in formulating cultivar recommendations for small-grain producers. The tests are conducted at the Northeast Research and Extension Center at Keiser, the Vegetable Substation near Kibler, the Lon Mann Cotton Research Station near Marianna, the Newport Extension Center near Newport, the Rohwer Research Station near Rohwer, the Pine Tree …


Summaries Of Arkansas Cotton Research 2018, Fred Bourland Sep 2019

Summaries Of Arkansas Cotton Research 2018, Fred Bourland

Arkansas Agricultural Experiment Station Research Series

Arkansas ended the 2018 season ranked 5th nationally in harvested acres (480,000 acres), 4th in lint yield (1150 lb/acre), and 4th in total production (1,150,000 bales). The string of consecutive years with good yields is helping to drive the increase in cotton acres. Harvest and ginning capacity is a major limiting factor for acre expansion. Cotton planting intentions for 2019 released in late March are at 580,000 acres, up 20% from the 485,000 acres planted in 2018. This continues to push the ginning capacity of 28 gins in 2018 and on-farm picker capacity to the limit. Optimism for cotton is …


Nature-Guided Synthesis Of Advanced Bio-Lubricants, Trevor Romsdahl, Asghar Shirani, Robert E. Minto, Chunyu Zhang, Edgar B. Cahoon, Kent D. Chapman, Diana Berman Aug 2019

Nature-Guided Synthesis Of Advanced Bio-Lubricants, Trevor Romsdahl, Asghar Shirani, Robert E. Minto, Chunyu Zhang, Edgar B. Cahoon, Kent D. Chapman, Diana Berman

Center for Plant Science Innovation: Faculty Publications

Design of environmentally friendly lubricants derived from renewable resources is highly desirable for many practical applications. Here, Orychophragmus violaceus (Ov) seed oil is found to have superior lubrication properties, and this is based on the unusual structural features of the major lipid species— triacylglycerol (TAG) estolides. Ov TAG estolides contain two non-hydroxylated, glycerol-bound fatty acids (FAs) and one dihydroxylated FA with an estolide branch. Estolide branch chains vary in composition and length, leading to their thermal stability and functional properties. Using this concept, nature-guided estolides of castor oil were synthesized. As predicted, they showed improved lubrication properties similar to Ov …


The Database Of Identified Root-Specific Genes And Their Promoters In Maize, Sorghum, And Soybean, Gleb Moisseyev, Divith Rajagopal, Alix Cui, Kiyoul Park, Edgar B. Cahoon, Chi Zhang Aug 2019

The Database Of Identified Root-Specific Genes And Their Promoters In Maize, Sorghum, And Soybean, Gleb Moisseyev, Divith Rajagopal, Alix Cui, Kiyoul Park, Edgar B. Cahoon, Chi Zhang

Center for Plant Science Innovation: Faculty Publications

Root genes are essential to plants as they dictate factors such as the strength of the plant, reproductivity success, etc. However, in the status quo, studies on root genes are simply ineffective. To be more specific, currently, there are very few online databases of root genes and promoters, which essentially deters root gene studies from being successful. To fix this problem, our lab constructed and coded an online database that contains information about the roots of maize, soybean, and sorghum. We collected 1200 root genes and assessed the strength and success of a given gene. This online database of these …


Studies On Pathogenesis Of The Diseases Caused By Macrophomina Phaseolina And Phomopsis Longicolla On Soybean, Marcio Leizer Zaccaron Aug 2019

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 …


Effects Of Sudangrass Cover Crop And Soil Solarization On Weed And Pathogen Management In Organic Strawberry Production, Timothy Jacobs Aug 2019

Effects Of Sudangrass Cover Crop And Soil Solarization On Weed And Pathogen Management In Organic Strawberry Production, Timothy Jacobs

Master's Theses

Field and lab experiments were conducted to determine the efficacy of sudangrass (Sorghum X drumondii (Nees ex Steud.) Millsp. & Chase) cover crop management techniques and soil solarization on important agricultural weeds and pathogens in organic strawberry production in Central California. Lab experiments assessed the time needed to kill weed seeds at temperatures typically achieved during soil solarization (40°C, 45°C, 50°C, 55°C, and 60°C) in California. Seeds tested included little mallow, redstem filaree, bristly oxtongue, annual sowthistle, common purslane, nettleleaf goosefoot, and redroot pigweed. Efficacy of simulated …


Selectivity Of Infrared Heat Treatment On Inactivation Of Mycotoxigenic Fungi On Stored Grain, Shantae A. Wilson Aug 2019

Selectivity Of Infrared Heat Treatment On Inactivation Of Mycotoxigenic Fungi On Stored Grain, Shantae A. Wilson

Graduate Theses and Dissertations

Selective Infrared (IR) heating holds great potential to decontaminate spores of unsafe fungi in corn. The objectives for this study were to investigate the impact of exposing corn to infrared energy at selected peak wavelengths (λ), infrared intensities and treatment durations, followed by tempering for further inactivation of microbes on the grain and explore a method for decontaminating Aspergillus flavus (A. flavus) spores on corn. Freshly harvested corn with initial moisture contents (IMCs) of 16%, 20%, and 24% wet basis (w.b.) were used. The corn samples were treated at different infrared wavelengths (3.2, 4.5, and 5.8 μm) for 20, 40 …


The Effect Of Prescribed Burning On Wood-Decay Fungi In The Forests Of Northwest Arkansas, Nawaf Ibrahim Alshammari Aug 2019

The Effect Of Prescribed Burning On Wood-Decay Fungi In The Forests Of Northwest Arkansas, Nawaf Ibrahim Alshammari

Graduate Theses and Dissertations

Prescribed burning is defined as the process of the planned application of fire to a predetermined area under specific environmental conditions in order to achieve a desired outcome such as land management. This project used both morphological and molecular methods to identify and characterize the wood-decay fungi associated with the forests of northwest Arkansas—Pea Ridge National Military Park, Devil’s Den State Park, and the Buffalo National River—through frequent visits made between February 2018 and February 2019. In addition, in order to assess the effects of prescribed burning, incubation chambers were used to compare the growth of fungi from both unburned …


Rust And Viral Mosaic Diseases In Biofuel Switchgrass, Anthony A. Muhle Aug 2019

Rust And Viral Mosaic Diseases In Biofuel Switchgrass, Anthony A. Muhle

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Switchgrass (Panicum virgatum L.) is a perennial warm-season monocot that is indigenous to locations in North America east of the Rocky Mountains, and is considered a model grass for biofuel feedstock production. As switchgrass production increases, diseases pose a potential threat to biomass production and ethanol extraction. The two predominant switchgrass diseases in Nebraska are rust caused by Puccinia spp. and a viral mosaic disease caused by Panicum mosaic virus (PMV) and its associated Satellite panicum mosaic virus (SPMV). In this thesis, one study determined how SPMV affects PMV infection and systemic spread in two populations of switchgrass at different …


Dual Biological Control: Characterization Of Fungi And Bacteria To Control Granary Weevil And Fungal Pathogens Of Stored Grain, Gülçin Ercan Aug 2019

Dual Biological Control: Characterization Of Fungi And Bacteria To Control Granary Weevil And Fungal Pathogens Of Stored Grain, Gülçin Ercan

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Cereals are main food sources for humans and animals. However, during storage, cereal grains can be infested by insects and fungi. One of the most important insect storage pests is Sitophilus granarius (L., Coleoptera: Curculionidae). Adults and larvae can cause serious grain losses. In addition to insect pests, fungal pathogens may also invade the grain and cause economic loss, including contamination with mycotoxins, which threaten mammal health by causing serious disease. The most common mycotoxigenic grain fungi are species that belong to the genera Fusarium, Aspergillus and Penicillium. Currently, the most commonly used management strategies for insect and …