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Impact Of Copper-Containing Products And Irrigation On Hybrid Bermudagrass (Cynodon Dactylon (L.) Pers X C. Transvaalensis Burtt-Davy), Adam Gore

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Copper (Cu) is an often-seen component in various turf industry products including fungicides, algaecides, and colorants. Though an essential micronutrient in plants, excessive levels of Cu has been shown in various plant commodities to cause phytotoxicity and plant death. With the increasing use of pigments on hybrid bermudagrass [Cynodon dactylon (L.) Pers x. C. transvaalensis Burtt-Davy] putting greens to replace overseeding practices during traditional dormant periods combined with regular applications of fungicide, algaecide and spray additives containing Cu, the objective of this study was to investigate the potential impact of individual and combined copper-containing treatments on hybrid bermudagrass and …

Biology And Herbicide Resistance Characteristics Of Various Annual Bluegrass (Poa Annua L.) Biotypes From Across The United States, Jacob William Taylor

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Annual bluegrass (Poa annua L.) is one of the most problematic winter annual weeds in managed turfgrass systems, having rapidly adapted to different climates and management practices. Characteristics such as prolific seedhead production, clumped bunch-type growth habit, and lack of stress tolerance negatively impact turfgrass quality. Achieving adequate control can be difficult because annual bluegrass exhibits high levels of genetic diversity, the ability to germinate year-round, and has a high tendency for evolving herbicide resistance, currently resistant to at least nine different herbicide sites of action. Current management programs rely heavily on herbicides for control; however, frequent use without implementing …

Exploring Soil-Tree Interactions After Applying Organic Matter Amendments To Peach Orchards In The Subtropical Climate Of The Southeastern United States, Brian Lawrence

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Soil disturbance from the cultivation and intensive management of orchards in hot and humid subtropical climates can reduce soil organic matter (OM). This research explored how the addition of OM amendments impact soil and tree parameters in two field studies and how proximity to OM may elicit unique genomic response of peach roots in a split-root pot study. The first field study applied two rates of compost (1x and 2x) and subsequently reduced fertilizer applications annually to a virgin and replant orchard location. While both compost rates successfully replaced fertilizers, only the 2x rate in the replant location increased soil …

Etiology And Epidemiology Of Mini-Ring In Ultradwarf Bermudagrass Putting Greens, Lukas Dant

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Mini-ring is a disease in ultradwarf bermudagrass (UDBG) [Cynodon dactylon (L.) Pers. × C. transvaalensis (Burtt-Davy)] putting greens caused by Waitea zeae (Voorhees) J.A. Crouch & Cubeta, (formerly Rhizoctonia zeae). Symptoms typically resemble frog-eye patches that are 10 to 40 cm in diameter with a bronze to orange outer ring and green center. In the southeastern United States, mini-ring symptoms appear in late-summer and generally persist until UDBG dormancy in late-fall. Mini-ring is often problematic in UDBG when nitrogen (N) fertility is reduced to manage organic matter production and improve putting green performance and perceived green speed. While …

Unveiling The Potential Of Calcium And Natamycin For Botrytis Blight Management On Cut Roses, Melissa Munoz

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Botrytis blight caused by the fungus Botritys cinerea is the most devastating disease of cut roses. The extensive use of fungicides used for Botrytis blight management during cut rose production and postharvest represents a severe threat in terms of fungicide resistance development as has been previously reported. Additionally, health concerns for growers and the environment are growing in recent years making consumers more aware of the fungicides in the products that they consume including ornamentals. This scenario highlights the importance of searching for alternative products to synthetic fungicides. During this research, the use of calcium as an alternative management strategy …

Cover Cropping To Improve The Sustainability Of Agronomic Production Systems, Ricardo St Aime

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The adoption rate of cover cropping among farmers in the Southeast is low due to the lack of knowledge regarding the suitable cover crop species and their management practices and the concerns of resource depletion for the subsequent cash crop. To generate information addressing the above knowledge gap, the present research was conducted with the following objectives: (1) to determine the optimal planting method for winter cover crops in the upstate of SC and whether it is influenced by the seeding rates (Project-1); (2) to determine suitable winter cover crops for the region based on biomass production, water use efficiency …

Distribution And Management Of Phytophthora Species On Lavender In The United States, Daniel Dlugos

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Phytophthora root and crown rot (PRCR) is currently the most important disease on lavender (Lavandula spp.) in the United States. The disease was first described on English lavender (L. angustifolia) in a Maryland nursery in 1991, with Phytophthora nicotianae as the causal agent. Since that time, the disease has been reported on multiple continents and as caused by several species of Phytophthora. This study examined the distribution and pathogenicity of Phytophthora species on lavender in the United States, requested lavender grower feedback regarding their production and concerns, and examined efficacy of selected management options. Lavender …

Lentil (Lens Culinaris Medik.) Prebiotic Carbohydrates And Protein Quality: Uncovering Genomic Associations And Developing Rapid Ftir Phenotyping Methods, Nathan Johnson

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Lentil (Lens culinaris Medik.) is a cool-season food legume cultivated around the globe. This pulse crop boasts a rich nutrient profile including high concentrations of prebiotic carbohydrates, protein, essential amino acids, and micronutrients, such as folate, iron, zinc, and selenium. Prebiotic carbohydrates promote a healthy gut microbiome, which, in turn, is associated with reduced risk of numerous pathologies including obesity/overweight, type II diabetes, irritable bowel disease, and colon cancer. Known as “poor man’s meat,” lentil also provides high quality plant-based protein at a low cost. As the world increasingly looks to crops to supplement and replace animal-based protein, lentil …

Crosscutting Understandings Of Fusarium Resistance In Sorghum And Wheat For Development Of Breeding Strategies And Novel Opportunities In Germplasm Improvement, Arlyn Ackerman

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Fusarium causes widespread disease in crops resulting in yield and quality loss across a range of host taxa that results in global incidence of carcinogenic mycotoxins contaminating the world’s food systems. This research sought to crosscut frameworks developed across the Fusarium host crop species of wheat (Triticum aesitivum) and sorghum (Sorghum bicolor [L] Moench) to further understand mycotoxin suppression and resistance. A deeper understanding of the biochemical resistances available in sorghum grain mold (SGM) was built by following research of wheat based upon deoxynivalenol resistance to Fusarium head blight (FHB). Through this research, phenotyping methods for Fusarium damaged kernels …

Recapture And Reuse Of Nitrogen And Phosphorus From Rendered Animal Materials To Enhance Nutrient Use Efficiency And Produce Quality In Agricultural Crop, Bhupinder Jatana

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The current fertilizer regime heavily relies on inorganic fertilizers to meet the crop nitrogen (N) and phosphorus (P) demand. However, the United States has a limited N production capacity, with 50% N demand met through imports. On the other hand, the nonrenewable natural reserves of P are being depleted at an unprecedented rate and are expected to be exhausted with in next 100 years. Additionally, high solubility/liability of the field applied inorganic fertilizers often results in lower nutrient use efficiency (NUE;

The MBM led to rapid N mineralization, with 35% of the applied N mineralized within the first five days …

Uav-Assisted Water Quality Monitoring, Cengiz Koparan

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Water quality assessment for the management of water resources requires the collection of water samples for physical, chemical, and biological analysis. It is essential to reduce the cost of water quality monitoring by minimizing the number of grab samples and to reduce the sampling time by rapidly accessing the sampling points. Adaptive, remote, and smart water sampling systems can provide more effective water quality monitoring programs. An adaptive water sampling system with an unmanned aerial vehicle integrated with sensor nodes was developed and tested in this research. Individual phases of this research were; in-situ water quality measurements with a UAV-integrated …

Magnolia: Impact Of Interspecific Hybridization On Genetic Variation And Ongoing Breeding Initiatives, James Kevin Parris

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The genus Magnolia comprises over 250 species naturally occurring in Eastern North America, Central America, South America, islands of the Gulf of Mexico, and Eastern Asia. A long history of cultivation and breeding going back to the early nineteenth century reveals a common trend of reproductive compatibility throughout this group of basal angiosperms. Interspecific hybridization has led to plethora of ornamental cultivars that have proven adaptable to natural and cultivated habitats beyond the range of each species. Understanding of taxonomic relationships between species has evolved as observations of morphological characteristics and genetic analyses have been more thoroughly investigated. The objectives …

Nematicidal Activity Of Extracts From Phytolacca Americana On Five Plant-Pathogenic Nematode Species Of Economic Importance, Saleh Ahmed

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Plant-parasitic nematodes cause significant losses to plant agriculture annually. The limited availability and high cost of synthetic nematicides, along with the environmental risks associated with their use, have created a renewed interest in the search for alternative management tactics. One such alternative tactic is the use of plant extracts. The focus of this research is the evaluation of the nematicidal activity of water extracts from Pokeweed (Phytolacca americana). In vitro and greenhouse tests were performed to evaluate the effects of the extracts on five species of plant-pathogenic nematodes of economic importance: Aphelenchoides fragariae, Ditylenchus dispsaci, Meloidogyne incognita, Pratylenchus penetrans, and …

The Detection And Characterization Of Some Viruses Infecting Blackberry And Cherry In South Carolina, Bindu Poudel

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Three separate virus research projects were conducted. Blackberry yellow vein disease (BYVD), a disorder caused by virus complexes, has become a major threat to blackberry production in the United States, especially in the southeastern part of the country where blackberries are grown for the fresh market. More than 30 viruses have been found to be associated with the disease. Most of these induce no symptoms when infecting the plant alone. However, when more than a single virus is present in the host visible symptoms are displayed. The incidence of 6 different viruses (Blackberry yellow vein-associated virus, Blackberry virus Y, Blackberry …

Spatial Distribution And Genetic Variability Of Reniform And Lance Nematodes In Cotton Agroecosystems, Claudia Holguin

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Rotylenchulus reniformis (reniform nematode) and Hoplolaimus columbus (Columbia lance nematode) are two of the main plant-pathogenic nematode species affecting cotton production in the United States. For the selection and implementation of effective management practices it is important to understand distribution patterns and population genetic structure of these two nematodes in cotton agroecosystems. In a three-year field study, the spatial distribution of reniform nematode was characterized in two commercial fields in South Carolina to determine the effects of relations with soil texture and crop rotation on reniform nematode distribution (Chapter 1). Results of this project suggest that population densities of reniform …

Evaluation Of A Mycorrhizal-Like Fungus, Piriformospora Indica, On Floriculture Crops, Allison Justice

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Piriformospora indica is a fungal endophyte, often called an arbuscular mycorrhizal-like fungus, that has been shown to provide benefits to plant symbionts by increasing nutrient uptake, biomass production, flower number, and disease resistance in a wide range of plant hosts. Research was carried out to investigate the ability of P. indica to improve plant production in floriculture crops. The first objective was to determine the optimal environmental conditions for growing P. indica in pure culture. Environmental conditions were optimized to produce the maximum chlamydospores for inoculum preparation (Chapter 1). These findings were used in the remaining chapters to prepare inocula …

Biology, Ecology, And Control Of Doveweed (Murdannia Nudiflora [L.] Brenan), Jeffrey Atkinson

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Doveweed (Murdannia nudiflora [L.] Brenan) is a summer annual in the Southeastern United States with an expanding geographic range. The light green color and texture of doveweed is problematic for turfgrass managers as it contrasts with the color and texture of desirable turfgrasses. Limited research is available concerning the biology, ecology, and herbicide control options for doveweed. Therefore, experiments were conducted to improve the understanding of how environmental conditions effect doveweed germination, how cultural practices and environmental resource availability effect doveweed growth and development, to identify pre- and postemergence herbicides with efficacy for doveweed control, and to improve the understanding …

Factors Influencing The Distribution And Structure Of Tropical Vascular Epiphyte Communities At Multiple Scales, Carrie Woods

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Understanding the factors that determine species distributions is a central question in ecology. Niche-based theories stress the importance of environmental heterogeneity in influencing species distributions while neutral-based theories emphasize the effects of dispersal limitation. The relative importance of these factors in influencing species distributions may depend on spatial scale - deterministic factors may be more important at small spatial scales where fine-scale habitat factors become more relevant and stochastic factors may be more important at larger spatial scales where dispersal limitation becomes more relevant. I examined the influence of deterministic and stochastic factors on the distribution and structure of vascular …

Effects Of Varying Spring Hollow Tine Aerification Size And Timing On Bentgrass Greens, Lewis Hubbard Jr

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The desire to maintain optimal turfgrass and surface properties often leads turfgrass managers to minimize impact from cultural practices like hollow tine aerification (HTA). Comprehensive research is essential to developing aerification programs which allow optimal use of turfgrass surfaces without sacrificing overall turf health.
A two-year field experiment was conducted on a 14-year-old U.S. Golf Association (USGA)-specified Crenshaw creeping bentgrass [Agrostis stolonifera L. var palustris (Huds.)] research putting green in Clemson, SC, to evaluate the effects of varying spring HTA size and timing on turfgrass, surface, organic matter (OM), and soil properties.
Spring HTA treatments included 1.2-cm i.d. tines spaced …

Transforming The South Carolina Botanical Garden, Amy Blackwell

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This dissertation addresses the question of how to transform a small to mid-sized public garden into a botanical garden capable of making a significant contribution to science. Botanical gardens have certain features that distinguish them from pleasure gardens and public parks. These include a scientific basis for collections, an emphasis on recording data on the plants in the collection, exchanging plant materials and data with other botanical gardens, and providing educational information to visitors. Gardens often have several missions, including conservation of rare and endangered species, botanical and ecological research, and involving the public through citizen science. I describe my …

Foliar Applied Urea Nitrogen Metabolism In Warm-Season Turfgrass Under Salinity Stress, Nicholas Menchyk

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The most widely used foliar nitrogen (N) source for warm-season turfgrass and agriculture is urea [(NH2)2CO], due to its low cost, high percentage of N (46% by mass), and completely soluble nature. Since urea is a soluble N source, it is commonly utilized as a foliar N source when tank mixed with pesticides in warm-season turfgrass management. The N in urea is not directly available to the plant until it is hydrolyzed into ammonia by the enzyme urease in the cytosol. Urease is a nickel (Ni2+) dependant enzyme that is ubiquitous in plants. Its main biochemical function is the hydrolysis …

Biology, Histopathology, And Improvements In Axenic Culture Of Labyrinthula Terrestris, Causal Agent Of Rapid Blight Of Cool-Season Turfgrasses, Kirthi Kiran Yadagiri

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Rapid blight is a disease of cool-season turfgrasses caused by Labyrinthula terrestris. Disease symptoms include water-soaked lesions, yellowing and browning of foliage, and coalescing patches of dead turf. L. terrestris belongs to a group of marine microorganisms in the kingdom Chromista (also known as Stramenopila). Morphological characteristics of Labyrinthula spp. include spindle-shaped vegetative cells that move in an ectoplasmic network. The biology and pathology of L. terrestris is not clearly understood; therefore, the ultrastructure, life cycle, and histopathology of L. terrestris were investigated. In addition, improvements in axenic culture and long-term storage methods were made to better culture L. terrestris. …

Sensor Based Irrigation Effects On Root Distribution And Growth Of Grafted And Non-Grafted Watermelons, Gilbert Miller

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ABSTRACT
Watermelon rooting patterns, root dry weight, plant biomass, stomatal resistance, root-to-shoot ratio, fruit yield, and fruit quality were evaluated in field trials during 2008, 2009 and 2010, using three irrigation regimes and three plant types. Plant types included: `Wrigley' grafted on Cucurbita moschata x Cucurbita maxima cv. Chilsung Shintoza; `Wrigley' grafted on Lagenaria siceraria cv. Fr Strong; and `Wrigley' not grafted. The irrigation regimes were: (1) No irrigation (NI) (30 minutes per day for fertigation only); (2) 50% and (3) 15% available water depletion (AWD) in the 0-30 cm soil profile triggered irrigation. Each whole plot contained a Sentek …

The Foliar Nematode Aphelenchoides Fragariae: Studies On Facultative Feeding And Desiccation Tolerance, Zhen Fu

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The foliar nematode Aphelenchoides fragariae is an economically important and frequent pest of ornamental crops. In nurseries and landscapes in the United States, foliar nematodes can be a serious problem affecting hostas (Hosta spp.), a common perennial ornamental plant that thrives in shady environments. Fundamental research on the biology and ecology of this nematode provides the basis for development of sound management strategies. The general objective of this dissertation was to study two behaviors that make foliar nematodes very successful as plant pests: desiccation tolerance and alternative feeding on fungi (or facultative feeding on the plant). To study the molecular …

Influence Of The Postharvest Environment On The Storage Potential And Propagation Performance Of Unrooted Cuttings Of Herbaceous Ornamentals, Amy Enfield

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Plants propagated from vegetative cuttings have become an increasingly important market in the United States. Significant economic losses occur annually due to poor performance, damage or death of cuttings. This occurs in large part due to the industry's lack of knowledge of the proper postharvest environments to provide to cuttings. This project was conducted to improve the understanding of the postharvest physiology of unrooted cuttings in order to optimize performance and longevity. Experiments were conducted to quantify the effect of temperature on respiration and ethylene production rates of unrooted cuttings. Additionally, the effect of the stock plant environment on the …

An Ecological, Genetic, And Reproductive Study Of Big Bluestem (Andropogon Gerardii) Populations In The Carolinas, Robert Tompkins

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ABSTRACT
AN ECOLOGICAL, GENETIC, AND REPRODUCTIVE STUDY OF BIG BLUESTEM (ANDROPOGON GERARDII) POPULATIONS IN THE CAROLINAS
Andropogon gerardii (Big Bluestem) is a dominant grass of the North American tallgrass prairie and is also found in remnant populations in the eastern U.S., including North and South Carolina. This research included a systematic study of the ecology, genetics, and reproductive potential within and among A. gerardii populations in the Carolinas. Floristic composition and edaphic (soil) features were characterized for eight A. gerardii populations across various physiographic regions of North and South Carolina. A total of 362 quadrats (1 m x 1 m) …

Population Variability Of Rotylenchulus Reniformis In Cotton Agroecosystems, Megan Leach

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Rotylenchulus reniformis, reniform nematode, is a highly variable species and an economically important pest in many cotton fields across the southeast. Rotation to resistant or poor host crops is a prescribed method for management of reniform nematode. An increase in the incidence and prevalence of the nematode in the United States has been reported over the last two decades. However it is not clear whether the observed increase is related to the emergence of novel populations that are more aggressive or have a higher fitness or shifts in host availability or susceptibility. The objectives of this research were to determine …

Nitrogen And Phosphorus Remediation Of Aquatic Garden Plants In Laboratory-Scale Constructed Wetlands., Robert Polomski

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This research investigated the potential of growing marketable aquatic garden plants that also remediate nursery and greenhouse runoff in a subsurface-flow constructed wetland. The cost of wastewater treatment is offset by the production of revenue-generating horticultural crops. Aquatic garden plants that offer the dual benefits of nutrient remediation and aesthetic value may also be planted in bioretention basins, rain gardens, buffer zones, and filter strips.
Fifteen commercially available aquatic garden plants were grown for 8 weeks in a laboratory scale subsurface wetland in a greenhouse and received nitrogen (N) and phosphorus (P) from Hoagland's nutrient solution every two days for …

Biology And Ecology Of Wild Radish (Raphanus Raphanistrum), Mayank Malik

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Wild radish ( L.), a facultative winter annual is a troublesome weed in small grain crops of the Southeastern United States. Besides being a weed, it may also be used as a cover crop for weed management due to its production of glucosinolates. Studies were conducted to evaluate the biology and ecology of wild radish as well as its glucosinolate production and its weed management possibilities.
Wild radish emerging in fall months formed a rosette of leaves which aided its winter survival. Plants emerging from December through March that did not form a rosette had minimal survival. Wild radish life …

Biology And Ecology Of Palmer Amaranth (Amaranthus Palmeri), Prashant Jha

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Palmer amaranth (Amaranthus palmeri S. Wats.) is a troublesome weed of crops in southeastern United States. This research highlights studies on the biology and ecology of Palmer amaranth. Following dispersal in fall, Palmer amaranth seeds require high mean temperatures of 25 to 40 C for germination, which is not likely to occur in South Carolina until the following spring. With dormancy reduction over winter, seeds can germinate at high temperatures (≥25 C) and thermal amplitudes of 15 C during late spring (May) in the presence of light. A majority (>90%) of the non-dormant population in the soil seedbank emerge …