Plant Pathology Commons^™

Managing Interspecies Competition To Improve Spring Pasture, Kelly M. Mercier, Eric D. Billman, K. Soder, D. M. Jaramillo, Sarah C. Goslee, P. A. Adler

IGC Proceedings (1977-2023)

Orchardgrass (Dactylis glomerata L.) is one of the earliest maturing pasture grasses utilized in the northeastern United States. However, wet springs can delay forage harvesting resulting in advanced forage maturity and reduction in nutritive value. Chicory (Cichorium intybus L.) is a tall, upright-growing forb that shows promise as a high-energy companion crop to orchardgrass and may delay orchardgrass maturity through shading effects on plant morphology. The objective of this study was to evaluate monocultures and mixtures of orchardgrass, chicory, and white clover (Trifolium repens L.) over two consecutive springs to determine the effects of species diversity on …

Nutritive Value Of South-Central Kentucky Forbs, Tyler M. Miller, S. R. Smith

IGC Proceedings (1977-2023)

South Central Kentucky pastures serve as a host for a plethora of forbs found throughout the Upper South and Midwest United States. In this region, forbs can be numerous within pastures that are under- managed. Many producers view forbs as unwanted or weedy species and may not fully understand the value that some of these forbs provide to beef cattle. With little scientific information found on the subject for the specific geographic area, the purpose of this study was to determine what types of forbs will provide adequate nutrition for lactating beef cows. Three pastures from separate farms were used …

Irrigation Effects On Forage Dry Matter Yield And Nutritive Value Of Alfalfa, Rudra Baral, Doohong Min

IGC Proceedings (1977-2023)

Alfalfa (Medicago sativa L.) is among the top four field crops in United States (U.S.) in terms of acreage harvested and economic value. Several studies have documented that alfalfa requires high amount of water compared to other major field crops. However, more than 65% alfalfa in the U.S. is grown under rainfed condition where severe to moderate drought condition has been pronounced during alfalfa growing season. The magnitude of yield loss due to water-limited conditions is still unknown. In this context, the objective of our study is to evaluate the forage dry matter yield and forage nutritive value of …

Gge Biplot Analysis Of Forage Yield Performance And Stability Assessment Of Tall Fescue Experimental Populations Selected Under Grazing Pressure In A Stress Environment, Ali Missaoui, J. L. Ford, D. R. Woodfield, A. Stewart, S. Makaju

IGC Proceedings (1977-2023)

Integrating the yield and stability of genotypes selected under grazing pressure is an important objective in breeding forage crops. Genotype × environment (G x E) interaction is a major source of inconsistency in crop performance across locations. As a result, a genotype is considered stable if it has a low contribution to the G x E interaction. This study explores the effects of G x E interaction on yield and stability of 10 tall fescue experimental populations selected for persistence under grazing pressure outside the area of adaptation of the species (stress environment). Six standard checks were included. The populations …

Identification Of Endangered Range Plant Species And Change In Ground Cover In North Kordofan State, Sudan, Mohammed D. Elnazeir, A. A. Khatir, A. M. Morakah

IGC Proceedings (1977-2023)

This study was conducted in North Kordofan State. With the objectives of identifying change in ground cover, other range attributes and the endangered plant species. The primary source of data was mainly from previous studies, while secondary data were obtained from field work using loop and transect method, personal interviews, rapid rural appraisal technique and direct observation, SPSS software was used in statistical analysis. The results indicate that there were notable changes in range composition. Percentage live plants and decreased by 17.5, while litter and rock increased by 17.9% and 0.30%. Some of the species still exist, with higher percentage …

Strategies For Seed Quality Improvement In Eastern Gamagrass, A Tripsacum Species, J. I. Morrison

IGC Proceedings (1977-2023)

In the southeastern United States, perennial warm-season grasses constitute the backbone of many forage production systems, whether for grazing or harvested feed. North American native plants offer unique ecosystem benefits as well as high forage quality when managed properly. Popular native grasses used for grazing in the southeastern US include Andropogon (bluestems), Sorghastrum (indiangrass) and members of the genus Tripsacum including eastern gamagrass (T. dactyloides) in North and Central America; Guatemala grass (T. fasciculatum syn. T. andersonii) in Latin America and the West Indies; and wide-leaf gamagrass (T. latifolium) throughout Mesoamerica. Eastern gamagrass …

Chlorophyll And Mineral Dynamics Of Perennial Grass Species Found In Semi- Arid Rangelands Of South Africa, N. H. Msiza, K. E. Ravhuhali, H. K. Mokoboki, Sydney Mavengahama, L. E. Motsei

IGC Proceedings (1977-2023)

Minerals are essential for ruminants and are mostly provided by grass species. Their growth stage is vital in the supply of these minerals. Perennial grass species have been mostly undervalued, owing to the scarce information concerning their potential feeding value and little documentation about their potential nutritive value in different growth stages. This study was conducted to investigate the chlorophyll and mineral concentration of grass species at different growth stages under greenhouse conditions at the North-West University Experimental farm, North West province, South Africa. The soil, collected from different villages, was mixed and samples were drawn for chemical analysis before …

Farmer Experiences With Alfalfa In The Southern U.S.A., M. K. Mullenix, L. S. Silva, C. G. Prevatt, J. J. Tucker

IGC Proceedings (1977-2023)

Alfalfa (Medicago sativa L.) is a forage crop of primary importance in the United States (USA); however, adoption and use in the southern USA region has been limited. The combination of adapted alfalfa cultivars and management strategies which demonstrate extended forage growing season length, improved forage nutritive value, and reduced N fertilizer inputs have renewed interest in forage-livestock farmers to consider planting alfalfa. A series of Extension-based educational strategies have been used in the southern USA to 1) create awareness on the use of alfalfa, 2) educate farmers regarding establishment and management practices, and 3) showcase opportunities and challenges …

Opportunities For Promoting The Adoption Of Forages In Kenya, Joseph G. Mureithi, Elkana M. Nyambati

IGC Proceedings (1977-2023)

Livestock production plays an important socio-economic role in many areas across Kenya. They are kept in all the major livestock production systems including smallholder mixed crop- livestock system, crop-livestock-tree production system, and pastoral/extensive livestock production system, which occupy about 70% of land in Kenya. Livestock production is mainly constrained by inadequate feed quantity and quality. Forage forms the major source of feed for ruminant livestock as they provide high-quality forage to alleviate feed shortages. The demand for pasture and fodder production and conservation to meet livestock feed requirements, particularly during the dry seasons, has created the need to re-position the …

Evaluation Of Apomictic Megathyrsus Maximus Accessions And Ecotypes To Improve Feed Availability In Western Kenya, David Miano Mwangi, S. W. Mwendia, Joseph G. Mureithi, P. Karimi, Maurice Mudeheri, An Notenbaert, Andres Juan, Tarus David

IGC Proceedings (1977-2023)

In Kenya, the dairy sub-sector is dominated by smallholder farmers, who keep between 1-10 dairy cows, and produce over 80% of the marketed milk in the country. The sub-sector is characterized by low milk production, long calving intervals and high calf mortality. The main constraint is the lack of year- round quality feeds hence the low lactation yield of 1,400 litres from animals capable of 3,500 - 4,000 litres. The main feed is Napier grass (Cenchrus purpureus) formerly Pennisetum purpureum. However, in the last decade the productivity and reliability of Napier grass has been constrained by the emergence Napier …

Annual Clovers Around The World: Current Status And Future Prospects, P. G. H. Nichols, G. R. Smith, D. J. Moot, Serkan Ates, Claudio Porqueddu, Esteban F. Rios, Mounir Louhaichi, Alejandro Del Pozo, N. Kotze, Alan W. Humphries, K. Ghamkhar, M. H. Ryan

IGC Proceedings (1977-2023)

This paper reviews the distribution and importance of annual clover (Trifolium) species for pasture and fodder production systems globally. Of the 158 recorded annual Trifolium species, 65.2% are endemic to the Mediterranean basin and surrounding areas, 14.6% to sub-Saharan Africa, 17.7% to the United States of America and 2.5% to Chile. Fourteen species have been commercialised, while other endemic and naturalised annual clovers are also utilised. Key species for self-regenerating pastures include T. subterraneum, T. michelianum and T. respinatum var. resupinatum, while major dual-purpose grazing and fodder species include T. incarnatum, T. vesiculosum, T. alexandrinum and T. …

Domestication Of The Annual Legume Trigonella Balansae For Mixed Farming Systems In Southern Australia, M. G. Wilmot, H. C. Norman, J. K. Hendry, P. Young, Elizabeth L. Hulm, A. Toovey, R. J. Harrison

IGC Proceedings (1977-2023)

An accession of the annual legume Trigonella balansae Boiss. and Reuter. has been selected for commercial release in Australia. The annual legume has significant potential as a self-regenerating pasture within mixed farming systems. As part of a duty-of-care assessment, we tested the hypothesis that sheep grazing the trigonella cultivar will have similar liveweight, condition scores, health and wool production to sheep grazing two widely adopted annual legumes, subterranean clover (Trifolium subterraneum L. cv Dalkeith) and French serradella (Ornithopus sativus Brot. cv. Erica). Forage dry matter digestibility (DMD), crude protein (CP), fibre, mineral content and isoflavones were measured across …

Pasture Production And Grazing System In Assist Project: Outcome And Replication Viability In Nigeria For Sustainable Ruminant Production, Okanlade A. Lawal-Adebowale, M. Jordana Rivero, John Hunt, Sarah Morgan, Hannah Fleming, R. Pywell, Jonathan Storkey

IGC Proceedings (1977-2023)

As important as pasture is to productive management of cattle, sheep and goats, intensive development of grassland for ruminant animals is rare in Nigeria largely due to no conscious effort at pasture cultivation in the country. Consequently, nomadic and free grazing systems remain a practice in the country, with resultant poor animal productivity and agro-related conflicts between ruminant keepers and crop farmers and/or agro-processors. The need to revert this situation underscored the exploration of the potential value of the innovative pasture production and grazing management system tested under the Achieving Sustainable Agricultural Systems (ASSIST) programmme in Rothamsted Research, United Kingdom, …

Tillering Of ‘Marandu’ Brachiaria Under Different Nitrogen Rates In The Brazilian Savannah, A. B. O. Assis, A. L. Bocchi, T. C. Pedrosa, A. O. Matos, A. P. B. Soares

IGC Proceedings (1977-2023)

The tiller is the basic unit of grass growth and tiller density determines the horizontal ground cover, leaves production and pastures perennially. The objective in this study was to quantify the number of aerial and basal tillers and basal:aerial tillers ratio in Urochloa brizantha cv. Marandu, established in Brazilian savannah, submitted to nitrogen doses (0, 50, 100 and 150 kg N/ha). The experiment was carried out in the Forage and Pasture Sector of Jataí Federal University (UFJ) and after soil correction and fertilization, plots were established with Marandu palisade grass in a randomized block design, with four replications and four …

Could Formononetin Of Red Clover (Trifolium Pratense L.) Be Enhanced By Phosphorus And Arbuscular Mycorrhizal Fungi Management?, Fernando Ortega-Klose, Andrés Quiroz, L. Bardehle, P. Aguilera

IGC Proceedings (1977-2023)

Red clover is a forage legume of importance in the world with limited persistency; in Chile this is due mainly to the root borer (Hylastinus obscurus Marsham) infestation. Our previous studies have shown that there is a strong relationship between the root borer and the formononetin content in roots of the plants; therefore, studying factors that enhance the concentration of formononetin in the plant could help to decrease the negative effect of the root borer. The purpose of this research was to assess the relationship between phosphorus availability (P) in the soil interacting with arbuscular mycorrhizal fungi (AMF) over …

The Influence Of High Density Grazing And Conventional, Rotational Grazing On Soil And Vegetation Parameters In The Semi-Arid And Mesic Grasslands Of South Africa, Jamie Paulse, C. Visser, P. J. Malan, G. N. Smit, F. H. De Witt

IGC Proceedings (1977-2023)

In South Africa, multi-camp rotational grazing using ‘conservative stocking rates’ have been the conventional approach to livestock grazing management systems. However, as of late, the high-desnity approach (used interchangeably – depending on the situation – with regenerative grazing, mob grazing, short duration, high pressure grazing, rapid rotation, time controlled, ultra-high density, holistic grazing and holistic resource management) has been adopted by numerous farmers. This approach is considered to be an adaptable one, incorporating the ‘herd effect’ concept, whereby large numbers of animals occupy an area for short periods of time, and allowed an extended rest period. It claims to improve …

Vascular Streak Dieback An Emerging Threat To The Redbud Nursery Production In The Southeastern United States, Fulya Baysal-Gurel, Prabha Liyanapathiranage

Extension Publications

No abstract provided.

Environmental Biology Masters Capstone, Antonio Gonzalez-Pita

Regis University Student Publications (comprehensive collection)

Human wildlife interactions (HWI) pose a complex challenge for wildlife managers. Human encroachment into wildlife habitat and the growing number of outdoor recreationists are increasing the frequency of contact and conflict, especially in regions such as the Front Range of Colorado. Geographic information systems (GIS), which use a combination of remote sensing and environmental survey data, allow for predictive spatial analyses of where human wildlife interactions are likely to occur. I used publicly reported observations of moose to create spatial predictive maps in a species distribution model framework. Slope and elevation were shown to be the strongest predictors of HWI, …

Watch Out For Putnam Scale, Diaspidiotus Ancylus, Alfred Daniel Johnson, Muhammad Ahmed,, Karla . M. Addesso

Extension Publications

No abstract provided.

Proceedings Of The 51st Annual Meeting, Southern Soybean Disease Workers (March 6-7, 2024, Pensacola Beach, Florida), Ian Small, Kiersten A. Wise, Travis R. Faske, Danise Beadle, Paul Patrick Price Iii, Tom W. Allen

Southern Soybean Disease Workers: Conference Proceedings

Success in Extension (moderator: Kiersten Wise)

Institutional currency: What is important at your university? Loren Giesler

Success (and challenges) in extension in the Mid-West, Daren Mueller

Success in extension in the Mid-Atlantic, Alyssa Koehler

Success (and failures) in xxtension in the Southeast, Ed Sikora

Success in extension in the Mid-South, Travis Faske

Student Competition (moderator: Ian Small)

Hiding in plain sight: Disentangling the biology of Cercospora species associated with Cercospora leaf blight of soybean, Ernesto da Silva, J. Searight, J. Richards, P. Price, and V. Doyle

Using spore traps to decipher the epidemiology of Cercospora leaf blight in the mid-south, …

The Effect Of A Signal Peptidase Mutation On Protein Secretion By The Maize Anthracnose Pathogen Colletotrichum Graminicola, Renata Belisario

Theses and Dissertations--Plant Pathology

Colletotrichum graminicola infects maize during several phases of plant growth, resulting in anthracnose leaf blight, stalk rot, and top die-back diseases. This ubiquitous fungus has significant destructive potential and causes millions of dollars of losses annually in North America. Colletotrichum graminicola is hemibiotrophic and initially invades living host cells via biotrophic primary infection hyphae before switching to necrotrophy and inducing host cell death, host cell-wall degradation, and lesion development.

An insertional mutation in the 3’UTR region of a gene (Cpr1), which encodes a homolog of the noncatalytic SPC22/23 subunit of the endoplasmic reticulum associated signal peptidase complex, completely …

Assessing Endophyte Frequency Distributions And The Effect Of Epichloë Brachyelytri In The Chemotypic And Genotypic Diversity Of Brachyelytrum Erectum, Rachel Ann Sneed

Theses and Dissertations--Plant Pathology

Seed-transmissible epichloid fungal endophytes are best known for their roles as defensive mutualists in cool-season grasses. Historically, the discovery of fungal endophytes was driven by investigations of plant toxicity to livestock, followed by extensive study of their alkaloids and protection against insects and nematodes. Epichloae can produce four classes of alkaloids: ergot alkaloids, lolines (saturated aminopyrrolizidines), indole–diterpenes, and peramine. It is increasingly evident that these hereditary symbionts have much more diverse chemical profiles both in individual populations and between them. To this end, differences in chemotypic profiles of these symbionts may translate to different evolutionary and environmental advantages across plant …

Role Of Autophagy-Related Genes In Lipid Transport For Efficient Replication Of Tombusviruses, Yuanrong Kang

Theses and Dissertations--Plant Pathology

Tombusviruses are positive-strand RNA viruses, which utilize numerous co-opted host factors and massive de-novo synthesized membrane resources to modify host membranes and form large viral replication organelles (VROs). Among plenty of host cellular processes, autophagy emerges as a potential membrane resource for VROs formation due to its ability to de-novo generate the double membrane structures, known as autophagosomes. Besides, as an important host defense pathway, autophagy is also a target for tombusviruses to prevent its antiviral activities. In this study, I identify the role of key autophagy related genes, Atg11, Atg8, and Atg2, which are involved in autophagosome formation, and …

Systemic Signaling In Plants: Role Of Cuticle, Salicylic Acid, Rna, And Vitamins, Huazhen Liu

Theses and Dissertations--Plant Pathology

Systemic acquired resistance (SAR) is a form of broad-spectrum resistance induced in response to local infection that protects uninfected parts against subsequent secondary infections. Several diverse chemical signals contributing to SAR have been isolated and characterized, including glycerol-3-phosphate (G3P) and pipecolic acid (Pip), both of which play an important role in human and plant disease physiologies. In addition to these, salicylic acid (SA) also regulates SAR and normal transport of SA and G3P is required for de novo biosynthesis of Pip in the distal leaves. Pip is catabolized via multiple pathways, and this in turn regulates vitamin homeostasis. A normal …

Biology And Ecology Of Neonectria Magnoliae And Neonectria Punicea, Two Understudied Neonectria Species In West Virginia, Hannah Marie Petronek

Graduate Theses, Dissertations, and Problem Reports (ETD)

The family Nectriaceae includes numerous phytopathogenic fungi that cause canker diseases on both angiosperm and conifer hosts worldwide. Numerous Neonectria spp. cause cankers on hardwoods and conifers in North America, but their roles in contributing to tree decline and mortality outside of beech bark disease are largely understudied. One such pathogen, Neonectria magnoliae, causes perennial cankers on two native hosts in central Appalachia: Fraser magnolia (Magnolia fraseri) and tulip-poplar (Liriodendron tulipifera). We also recently confirmed N. magnoliae from non-native star magnolia (Magnolia stellata) in West Virginia. Both native hosts occur in the central …

Investigation Of The Ecological Interactions And Host Specificity Of Verticillium Nonalfalfae, A Proposed Biological Control Agent Against The Invasive Tree-Of-Heaven (Ailanthus Altissima), Kristen H. Pierce

Graduate Theses, Dissertations, and Problem Reports (ETD)

Tree-of-heaven (Ailanthus altissima) is a highly invasive tree species with a cosmopolitan distribution, including an expansive range in North America. In the U.S., tree-of-heaven has established populations in more than 40 states and is considered among the most notorious of invasive plant species. The discovery of Verticillium nonalfalfae and V. dahliae causing acute wilt and mortality of Ailanthus in the mid-Atlantic in the 2000s has resulted in numerous studies evaluating the utility of these fungi as potential biocontrol agents. Recent efforts to commercialize V. nonalfalfae have raised additional questions about its widespread use and factors influencing long-term efficacy. …

A Gis Tool For Optimal Forage Species Selection, David B. Hannaway, Christopher Daly, Michael D. Halbleib, Linda Brewer, Sophie Baur, Chelsea Clark, Emilie Krecklow, Scott Bassett

IGC Proceedings (1977-2023)

To determine appropriate forage species for US ecoregions, geographic information technologies (GIS) are being used to create climatic and soil factor maps. Excel spreadsheets and RStudio are used to create response functions of forage species to minimum and maximum temperature, annual precipitation, soil pH, soil salinity, and salinity. National forage data and expert opinion will evaluate quantitative tolerances, seasonal yield profiles, and pollinator suitability. These maps and agronomic and livestock use information will be shared with forage specialists and farmers to provide alternatives for improved perenniality, increased diversity, and system circularity. Future work will include development and evaluation of climate …

Investigating Birds As Dispersal Vectors Of Litylenchus Crenatae Subsp. Mccannii (Anguinidae), The Nematode Associated With Beech Leaf Disease, Spencer Rock Parkinson

Graduate Theses, Dissertations, and Problem Reports (ETD)

Beech leaf disease (BLD) is an emerging forest pathogen primarily affecting American beech (Fagus grandifolia, Ehrh.) in North America and has been attributed to tree mortality of sapling sized trees within five to seven years of infection. Symptoms typically occur in regenerating American beech thickets sprouting from roots of trees killed by beech bark disease. Scientists first observed BLD in Ohio in 2012 and currently has spread to 15 states in the USA and one Canadian province. The nematode Litylenchus crenatae subsp. mccannii (Lcm) is highly associated with BLD symptoms, interveinal chlorosis and defoliation of leaves, and is currently …

Erwinia Amylovora Phage Therapy: Biocontrol Formulation, Receptor Identification, Resistance Mechanisms, Nassereldin Ibrahim

Theses and Dissertations (Comprehensive)

Fire blight is known as a disease of Rosaceae and it displays infection symptoms in about 200 species in 40 rosaceous genera. The most economically important crops that are affected by fire blight are apples and pears. Fire blight can cause severe outbreaks and a single fire blight outbreak can disrupt orchard production for years. The bacterium that causes this disease is indigenous in North America, and according to Statistics Canada, economic losses in apples and pears were valued at an estimated $4 million in 2005, which is approximately 5% of the total production. In addition, production costs can increase …