Plant Pathology Commons^™

Mutations In Virus-Derived Small Rnas, Deepti Nigam, Katherine Latourrette, Hernan Garcia Ruiz

Department of Plant Pathology: Faculty Publications

RNA viruses exist as populations of genome variants. Virus-infected plants accumulate 21–24 nucleotide small interfering RnAs (siRnAs) derived from viral RnA (virus-derived siRnAs) through gene silencing. This paper describes the profile of mutations in virus-derived siRNAs for three members of the family Potyviridae: Turnip mosaic virus (tuMV), Papaya ringspot virus (pRSV) and Wheat streak mosaic virus (WSMV). for tuMV in Arabidopsis thaliana, profiles were obtained for mechanically inoculated rosette leaves and systemically infected cauline leaves and inflorescence. Results are consistent withselection pressure on the viral genome imposed by local and systemic movement. By genetically removing gene silencing in the plant …

Variation Profile Of The Orthotospovirus Genome, Deepti Nigam, Hernan Garcia Ruiz

Department of Plant Pathology: Faculty Publications

Orthotospoviruses are plant-infecting members of the family Tospoviridae (order Bunyavirales), have a broad host range and are vectored by polyphagous thrips in a circulative- propagative manner. Because diverse hosts and vectors impose heterogeneous selection constraints on viral genomes, the evolutionary arms races between hosts and their pathogens might be manifested as selection for rapid changes in key genes. These observations suggest that orthotospoviruses contain key genetic components that rapidly mutate to mediate host adaptation and vector transmission. Using complete genome sequences, we profiled genomic variation in orthotospoviruses. Results show that the three genomic segments contain hypervariable areas at homologous locations …

Identification, Aggressiveness And Mycotoxin Production Of Fusarium Graminearum And F. Boothii Isolates Causing Fusarium Head Blight Of Wheat In Nebraska, Esteban Valverde-Bogantes

Department of Food Science and Technology: Dissertations, Theses, and Student Research

Fusarium head blight (FHB) is an economically important disease caused by several Fusarium species affecting wheat. Besides causing significant yield losses, infected grain may be contaminated with mycotoxins, primarily trichothecenes, that are harmful to both humans and animals. In recent years, reports of shifts in FHB pathogen populations in North America have highlighted the need for increased vigilance. This dissertation describes a four-year survey evaluating the species, trichothecene genotype and phenotypic diversity of FHB pathogens infecting Nebraska wheat. Most of the isolates were identified as F. graminearum (n=67). Additional species included F. boothii (n=3), F. poae (n=2) and F. acuminatum …

Improving Kentucky's Winter Wheat And Double Crop Soybean Rotation, Katherine Susan Rod

Theses and Dissertations--Plant and Soil Sciences

The winter wheat double crop soybean rotation is an economically viable rotation for Kentucky farmers. Recent decreases in commodity prices has warranted the need to evaluate intensive management practices that can increase yields and profitability in this crop rotation. There were three goals of this dissertation: 1.) identify management practices that would decrease deoxynivalenol (DON) in harvested wheat grain and increase wheat heading and anthesis uniformity, 2.) evaluate double crop soybean planting timing and identify intensive management practices to increase seed yield, and 3.) determine the profitability of these management options. These studies were conducted in Princeton KY between 2016 …

Draft Genome Assembly Of Passalora Sequoiae A Needle Blight Pathogen On Leyland Cypress, Warren E. Copes, Jorge Ibarra Caballero, Ebrahiem Babiker, Jane E. Stewart, Valerie A. Orner, Alan S. Windham, Renee Arias

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Objective: Passalora sequoiae (family Mycosphaerellaceae) causes a twig blight on Leyland cypress that requires numerous fungicide applications annually to minimize economic losses for ornamental plant nursery and Christmas tree producers. The objective was to generate a high-quality draft assembly of the genome of P. sequoiae as a resource for primer development to investigate genotype diversity. Data description: We report here the genome sequence of P. sequoiae 9LC2 that was isolated from Leyland cypress ‘Leighton Green’ in 2017 in southern Mississippi, USA. The draft genome was obtained using Pacific Biosciences (PacBio) SMRT and Illumina HiSeq 2500 sequencing. Illumina reads were mapped …

Inhibition Of Fusarium Oxysporum F. Sp. Nicotianae Growth By Phenylpropanoid Pathway Intermediates, Timothy E. Shull, Jasmina Kurepa, Robert D. Miller, Natalia Martinez-Ochoa, Jan A. Smalle

Plant and Soil Sciences Faculty Publications

Fusarium wilt in tobacco caused by the fungus Fusarium oxysporum f. sp. nicotianae is a disease‑management challenge worldwide, as there are few effective and environmentally benign chemical agents for its control. This challenge results in substantial losses in both the quality and yield of tobacco products. Based on an in vitro analysis of the effects of different phenylpropanoid intermediates, we found that the early intermediates trans‑cinnamic acid and para‑coumaric acid effectively inhibit the mycelial growth of F. oxysporum f. sp. nicotianae strain FW316F, whereas the downstream intermediates quercetin and caffeic acid exhibit no fungicidal properties. Therefore, our in …

Arthropod Resistant Tomatoes: Screening Tools, Yield And Nutritional Quality Of Interspecific Hybrids, Mohammad Hasan Salman Ali Dawood

Theses and Dissertations--Plant and Soil Sciences

Tomato (Solanum lycopersicum) is one of the most economically important vegetable crops grown around globe but is a host for numerous pests and pathogens. In the future, tomato breeders will have to focus on increasing fruit quantity and on enhancing pest resistance. Many accessions of the wild relative of tomato, S. habrochaites display high levels of resistance towards arthropods such as spider mites. The presence of the sesquiterpene hydrocarbon, 7-epi-zingiberene, found in S. habrochaites type IV trichomes has been associated with arthropod resistance. However, the presence of other compounds in its trichome secretions may also be related …

Occurrence, Mating Strategy, And Pathogenicity Of Members Of Nectriaceae In Central Appalachia, Cameron Michael Stauder

Graduate Theses, Dissertations, and Problem Reports (ETD)

Members of the Nectriaceae occupy many ecological niches including dominant canker pathogens, such as Neonectria ditissima and N. faginata. These two pathogens contribute to the decline of American beech (Fagus grandifolia) forests across the Appalachian Mountains due to beech bark disease (BBD). Interestingly, N. ditissima represents a well-known canker pathogen many hardwood species, while N. faginata has not been observed outside of BBD. Additionally, N. faginata occurs at higher incidences than N. ditissima in BBD stands. Nectriaceae in Central Appalachia were surveyed as to further characterize the diversity and possibly identify a non-beech host of N. faginata. …

Genetic And Biochemical Characterization Of Ergot Alkaloid Synthesizing Fungi And Their Symbionts, Matthew Duane Maust

Graduate Theses, Dissertations, and Problem Reports (ETD)

Ergot alkaloids are fungal tryptophan derived toxins which affect mammalian circulation and neurotransmission. These compounds are biosynthesized by a conserved genetic pathway, known as the ergot alkaloid synthesis (EAS) pathway by fungi belonging to the ascomycete families Trichocomaceae and Clavicipitaceae. Several Ipomoea species and related plants in the morning glory family harbor vertically transmitted symbiotic fungi in the genus Periglandula, also members of Clavicipitaceae, that produce ergot alkaloids. Metabolomic analysis of seeds identified a previously uncharacterized glycoside form of the pharmaceutically important ergot alkaloid, ergonovine. Several species belonging to the fungal genus Metarhizium have recently been shown to have the …

Metabolite Profiling Of Ganoderma-Infected Oil Palm Tree Grown On Ultisol And Oxisol Soil, Ahmad Muhamad Fadhil

Student Works (2020-2029)

The oil palm industry is a pillar of the Malaysian economy and plays a pivotal role in feeding and fueling a growing global population. In 2018, oil palm contributed 37.9% or RM37.7 billion to the country's' Gross Domestic Products (GDP) of agriculture sector. Despite achieving significant achievements in the industry, Ganoderma sp. infection that cause basal stem rot (BSR) and upper stem rot (USR) disease are considered a threat. The palm oil industry is expected to experience significant losses, thereby affecting yield production and ultimately the dead of trees. Some factors have been reported to affect the occurrence of the …

Can Precision Farming Technologies Be Applied To Grazing Management?, S. Mark Rutter

IGC Proceedings (1977-2023)

In arable farming, precision is used to monitor and manage crop variability. The same precision approach can be used to manage grassland, by using crop sensing, targeted fertilizer/herbicide/pesticide application and forage yield measurement when it is harvested mechanically. An additional challenge in grassland agriculture is developing precision approaches to manage the grazing process. This requires technologies to determine where an animal is, when, what and how much it is grazing which the system then needs to use in conjunction with other sources of information to control where the animal grazes next. This paper reviews the existing technologies in these …

Manipulation Of The Spatial Grazing Behaviour Of Livestock In Extensive Grassland Systems, Derek W. Bailey, Mitch B. Stephenson, Milton G. Thomas, Juan F. Medrano, Gonzalo Rincon

IGC Proceedings (1977-2023)

Spatial behaviour of livestock is a critical factor in grassland management. Recent and ongoing research suggests that new approaches can be used to manipulate where cattle graze. The combination of strategic supplement placement and low-stress herding can be used to target cattle grazing and potentially may be useful for managing fine fuels. A phenotype to genotype association study of cattle spatial behavior suggests that use of rugged terrain and areas far from water is inherited. Although more research is needed, selection for animals specifically adapted for mountainous terrain or extensive paddocks may be an alternative for managing grasslands in the …

Case Studies Which Demonstrate The Financial Viability Of Precision Dairy Farming, Ian Yule, Hayden Lawrence, Craige Mackenzie, Carolyn Hedley, Miles Grafton

IGC Proceedings (1977-2023)

A number of case studies are used to demonstrate the financial viability of precision farming methods for intensively managed pastures. Precision farming has sometimes been criticized as being technology-led where the management goals and desired outcomes are sometimes poorly defined. Case studies presented in this paper demonstrate a strong management approach where appropriate technologies are selected to contribute to the financial success of the farm. The first case study farm has increased milk production by 70% in four years, increased pasture production by 43%, reduced fertilizer costs to 43% of previous levels and has successfully predicted annual production to within …

Opportunities For Improving Livestock Production With E-Management Systems, Dave L. Swain, Rebecca N. Handcock, Greg J. Bishop-Hurley, Don Menzies

IGC Proceedings (1977-2023)

There is increased interest in hardware and software that can support e-Management for grassland-based livestock industries. Managers of grazing livestock were early adopters of radio frequency identification (RFID) technologies automatically monitoring individual animal performance. Recent developments of remote sensing, automated individual recording and management, location based systems, improved data transfer and technologies that can be used in more extensive grazing systems are providing new opportunities for the development of e-Management systems. There is a need for better data integration and systems that can provide the best available information to enable better decision-making. For greater industry adoption of more integrated e-Management …

Growth Of Bali Bulls Fattened With Forage Tree Legumes In Eastern Indonesia: Leucaena Leucocephala In Sumbawa, Tanda Panjaitan, Muhammad Fauzan, H. Dahlanuddin, Michael J. Halliday, H. Max Shelton

IGC Proceedings (1977-2023)

The contribution of West Nusa Tenggara Province to domestic beef supply in Indonesia is relatively small, however, beef cattle are very important for the livelihoods of smallholder farmers in the region.

Bali cattle (Boss javanicus) are the predominant breed as they are adapted to harsh nutritional conditions, are highly fertile and have low calf mortality (Toelihere 2003). While genetically capable of achieving a growth rate of 0.85 kg/d (Mastika 2003), Panjaitan (2012) identified poor nutrition as a severe limitation to animal growth in traditional village systems. Improving feed quality and supply is vital to increasing growth rates and …

Effect Of High Se And Co Alfalfa Forage On Animal Production, Xiao-Lei Jie, Xiao Guo, Hua-Feng Hu

IGC Proceedings (1977-2023)

Total and available selenium (Se) and cobalt (Co) concentrations are low in Chinese soils, especially those found in mainly in temperate humid sub-humid conditions in the northeast to the southwest band across China (Tan et al. 2002). The levels of Se and Co are marginally deficit in the brown soil of the Yellow River region which causes lower production level and quality in forage and crop plants. Application of Se and Co fertilizers to arable lands is essential to produce high Se and Co forages. Henan is a Province where produce high-quality grass forages are used to support dairy …

Pre-Conditioned Cattle Sales For Forage-Based Cow-Calf Management Systems, C. P. Bagley, L. S. Dale, B. C. Housewright

IGC Proceedings (1977-2023)

Demand for preconditioned feeder cattle continues to increase in the beef industry as value-based marketing and information flow expands indicating preconditioned forage-raised calves require less management, fewer losses due to illness and deaths, and increased profitability to both buyer and seller. The goal of a preconditioning program is to increase the value of weaned cattle (Bailey, 2002). The Northeast Texas Beef Improvement Organization (NET-BIO) is comprised of commercial cow/calf and stocker operators and various agribusinesses with the same interest. The objective of this study is to determine if prices received for preconditioned NETBIO stocker cattle increase the net income above …

Performance, Carcass Characteristics And Meat Quality Of Grazing Lambs Finished On Tropical Grasses, Cesar H. E. C. Poli, Samuel Carnesella, Fernando M. Souza, Concepta Mcmanus, Zélia M. S. Castilhos, Liris Kindlein, Jaime U. Tarouco

IGC Proceedings (1977-2023)

Brazil is a country of continental size, and more than seven million ha are occupied with tropical pasture. Worldwide animal production from tropical pastures is also very significant where Cynodon, Panicum and Paspalum are important genus. These grasses are widely used in the production of cattle, and are growing in importance for sheep production, but their potential for producing quality lamb is not fully known.

The objective of this study was to evaluate the potential of two tropical grasses for finishing lambs in autumn to reduce the seasonality of production of lamb for meat.

Alternative Pasture Development System And Breeding Weight For Beef Heifers, H. A. Lardner, Daalkhaijav Damiran, Steve Hendrick, Kathy Larson

IGC Proceedings (1977-2023)

Proper development of replacement beef heifers is critical and needs to be accomplished at lower costs without sacrificing reproductive performance. The current recommendations indicate heifers should reach approximately 65% of mature body weight (MBW) at breeding for successful reproduction (Patterson et al. 1992; NRC 1996). Meeting heifer maintenance and gestation nutrient requirements are getting more economically challenged for beef producers in western Canada. Therefore, producers are moving from drylot development systems where cattle are housed and fed in pens to the adoption of extensive grazing systems (Kelln et al. 2011) in field paddocks. Limited research has been conducted …

Variation Of Rumen Bacterial Diversity In Steers After The Beginning Of Grazing, Miwa Nakano, Satoshi Haga, Masanori Tohno, Kazuhiro Matoba, Ryuichi Uegaki, Hiroshi Ishizaki

IGC Proceedings (1977-2023)

Holstein heifers before or after puberty often are herded on public pastures in Japan. The herbage intake and rumen fermentation of grazing heifers that are not adapted for fresh herbage decreases due to a change of feed from stall-fed dried forage to fresh herbage. This limits their performance during the first several weeks on pasture. Thus, the feeding program such as supplementation before and after the beginning of grazing is important. An increase in ammonia concentration and a decline in fibre degradation in the rumen of a heifer (both of which occur simultaneously with low herbage intake and rumen fermentation) …

Forage Systems Effect On Forage-Fed Beef Production, Guillermo Scaglia, Basu Bhandari, Jeffrey M. Gillespie, Jim J. Wang

IGC Proceedings (1977-2023)

Locally produced forage-finished beef offers high value while enhancing economic, environmental, and social sustainability. It enhances environmental quality and the natural resource base, and makes good use of resources both on and off-farm. On the farm, it makes the most of the ability of cattle to convert grass to meat in a low-input system, making efficient use of solar energy, improving soil nutrient cycling, conserving soil and water, and limiting reliance on non-renewable resources (DeRamus 2004). Although the major causes of increased greenhouse gas emissions are due to population growth and industrialization, agriculture contributes to carbon dioxide (CO2) emissions through …

Activity, Physiology And Milk Production Of Yaks And Two Different Yak Crossbreds Grazing Himalayan Pasture Sites At 4700 M And 3000 M, Shanker R. Barsila, Naba R. Devkota, Michael Kreuzer, Svenja Marquardt

IGC Proceedings (1977-2023)

Yaks (Bos grunniens) and crossbreds of yaks with different local cattle breeds are important for the livelihood of local herders in the Himalayas. They are often kept in a system of transhumance comprising the use of different pasture sites for grazing along an altitudinal gradient throughout the year. The animals are moved upwards to the high altitude pastures in spring/early summer and gradually moved downwards in late summer/autumn. Yaks are suitable for very high altitudes as they are especially adapted to low oxygen partial pressure, forage scarcity and cold and harsh environment (Wiener et al. 2003). However, …

Fatty Acid Metabolism On Pasture- And Feedlot-Finished Cattle, Cuk T. Noviandi, Robert E. Ward, Jong-Su Eun, Dale R. Zobell, Rusty D. Stott, Blair L. Waldron, Mike D. Peel

IGC Proceedings (1977-2023)

Feeding high-grain diets to finishing beef cattle results in high proportions of saturated fatty acids (SFA) in the beef, which is considered to confer negative impacts on human health. In contrast, pasture-finished cattle produce lower proportion of SFA, greater n-3 and less n-6 polyunsaturated fatty acids (PUFA), and higher conjugated linoleic acids (CLA) compared to high grain-finished beef (Noviandi et al. 2012). Increased n-3 PUFA, especially C18:3 n-3, can reduce the risk of heart disease, hypertension, inflammation, and mammary cancer, and lower cholesterol concentration in blood (De Deckere et al. 1998; Tapiero et al. 2002).

Nitrogen fertilisation …

Development Of Feeding System Based On Azolla (Azolla Pinnata) And Sheanut Cake (Vitellaria Paradoxa) For Nellore Sheep Reared In Different Production Systems, K. Sarjan Rao, Y. Ravindra Reddy

IGC Proceedings (1977-2023)

Since protein sources such as ground nut cake and soya bean are too expensive to feed as supplements to livestock in India, steps have been taken to reduce cost by utilizing alternative feedstuffs to replace the traditional sources in ration formulation (Parashuramului et al. 2013). Azolla which is a free-floating nitrogen fixing water fern has a potential to be used as a protein supplement for ruminants (Ahirwar and Leela, 2012). Sheanut cake (Vitellaria paradoxa) which is produced after extraction of fats use in cosmetics and as a cocoa butter substitute in chocolate making, is also a rich …

Lca Study On Sheep Milk Production In Sardinian Farms At Different Input Levels, Enrico Vagnoni, Antonello Franca, Leo Breedveld, Claudio Porqueddu, Pierpaolo Duce

IGC Proceedings (1977-2023)

This paper illustrates a Life Cycle Assessment (LCA) study carried out with the purposes of comparing the environmental impacts of sheep milk production from three different dairy farms in Sardinia, Italy, characterized by different production systems.

Forage Allowance And Cow Genotype, Tools To Increase Animal Production In Native Pastures, Pablo Soca, Mariana Carriquiry, Martín Do Carmo

IGC Proceedings (1977-2023)

In eight plots (four per block) the effects of two FA per two cow genotypes were tested from August 2007 to March 2010, on a Campos grassland (major species were Axonopus affinis, Oxalis sp., Cyperus sp., Cynodon dactylon, Eryngium nudicaule, Gaudinia fragilis, Chevreulia sarmentosa, Stipa setigera, Paspalum notatum and Coelorhachis selloana) in Uruguay (32º 20` S, 54º 26` W). Forage allowance varied seasonally, in HIGH (5, 3, 4 and 4 kg DM/kg LW) and LOW (3, 3, 2 and 2 kg DM/kg LW) during autumn, winter, spring and summer; respectively. Continuous stocking method was …

Herbage Accumulation And Animal Performance On Xaraes Palisade Grass Subjected To Intensities Of Continuous Stocking Management, A. Hernández-Garay, Valéria P. B. Euclides, Sila C. Da Silva, Denise B. Montagner, Nayana N. Nantes, Domicio Nascimento Jr., C. O. Soare

IGC Proceedings (1977-2023)

The large majority of species used in Brazil belong to the Brachiaria and Panicum genus, with marandu paladisadegrass (Brachiaria brizantha (Hochst. ex A. Rich) cv. Marandu) being the main cultivated forage grass species (Santos Filho 1996). Brachiaria brizantha cv. xaraés (xaraes palisade grass) was released as an option for diversifying forage species, and it had the advantages of fast regrowth and herbage yield, favouring larger stocking rates and animal productivity (Euclides et al. 2008; 2009).

The objective of this study was to evaluate herbage accumulation and animal performance of beef cattle steers grazing continuously stocked xaraes …

Herb And Clover Mixes Increase Average Daily Gain (Adg) Of Finishing Lambs In Different Seasons, Sharini C. Somasiri, Paul R. Kenyon, Peter D. Kemp, Patrick C. H. Morel, Stephen T. Morris

IGC Proceedings (1977-2023)

Approximately half of the usable land area in New Zealand is under grasslands (Saggar 2001). Production of lamb meat is seasonal in New Zealand (Fisher 2004) with the majority of lambs born in the spring and slaughtered in late summer and autumn depending on the international demand (Clemens and Babcock 2004) and pasture growth pattern. Finishing lambs outside this window using high quality pastures would help to facilitate a continuous supply of meat to the domestic and international markets. Charlton and Belgrave (1992) and Kemp et al. (2010) reported that the use of herb-clover mixes instead of perennial ryegrass/white …

Cultivar Influences Milk Production Of Grazing Dairy Cows, Mary Mcevoy, Michael O’Donovan, Emer Kennedy, John Paul Murphy, Luc Delaby

IGC Proceedings (1977-2023)

Perennial ryegrass is considered one of the most important forage grass species used in temperate ruminant animal production systems. Maximizing milk production from grazed grass is a major objective of pastoral-based dairy systems. While DM yield is an important trait, it fails to define the ultimate value of a grass cultivar, which is its potential to improve animal performance from a pasture sward (Reed 1994). The majority of cultivar evaluation trials are conducted under cutting, so therefore inferior cultivars from an animal production perspective may not be identified until commercialisation when animals graze a pasture sward. Reed (1978) reported that …

Short-Term Milk Yield Response To Changes In Post-Grazing Sward Height, Elodie Ganche, Luc Delaby, Michael O’Donovan, Tommy M. Boland, Emer Kennedy

IGC Proceedings (1977-2023)

In temperate climates, grazed grass is the cheapest source of nutrients for the dairy cow (Finneran et al. 2010), therefore its utilisation should be optimised throughout the grazing season to increase enterprise profitability (Shalloo et al. 2004). Within spring-calving systems, energy requirements increase for the post-parturient dairy cow during the spring period. On the other hand, spring grass supply can be limited given low over-winter grass growth rates. The imposition of a lower post-grazing sward height (PGH) during this critical time may be a viable solution to increase grass availability. As the season progresses, PGH may be increased …