Life Sciences Commons^™

Identification Of Cytospora Species Isolated From Canker In Peach Trees In South Carolina, Stephen T. Baker

All Theses

In 2016, a survey was conducted into the causes of twig blight on peach (Prunus persica) in five orchards across South Carolina. From this survey, isolates from the fungal genus of Cytospora (Sordariomycetes, Diaporthales) were reported on peach, for the first time, within the state. Cytospora species are known to cause oozing cankers on a wide range of woody hosts leading to dieback, loss of limbs, and reduction in yield, prompting concern for important economic crops. Past methods of identification of Cytospora species have been confounded by indistinguishable morphology, overlapping host preference among species, and genetic sequencing …

An Examination Of Organic Options In Tomato Systems And Their Use As Alternatives To Copper-Based Products, Erica Ann Fealko

Theses and Dissertations--Plant Pathology

Organic farming is an ever-increasing segment of tomato production. Currently, limited information is available which directly compares conventional to organic treatment programs for disease control in tomato production. Furthermore, many methods available rely on the use of copper products which may be contribute to high Cu levels in agricultural soils. In this study, the efficacies of current conventional and organic methods were compared. In addition, newer disease-control programs, with and without copper were examined, which potentially could reduce over-reliance on copper products.

Standard organic and conventional spray programs were conducted over a four year period targeting two pathogens, Alternaria tomatophila …

Exploring The Host Range, Impacts, And Distribution Of Black Rot Disease On Alliaria Petiolata, Gabriela Ivette Harney-Davila

Browse all Theses and Dissertations

Garlic mustard is an invasive Eurasian biennial spreading in deciduous forests of North America. Garlic mustard plants in Ohio can be infected with a strain of Xanthomonas campestris, the causal agent of black rot disease in brassicas. I examined variation in susceptibility to X. campestris among garlic mustard populations, several native wild species, and agricultural crop varieties. Twenty-four garlic mustard populations were universally susceptible to X. campestris, though disease severity varied. Cardamine concatenata and Cardamine diphylla were susceptible but can phenologically escape infection in the field. Of the 14 agricultural crops tested, three cultivars (Raphanus sativus, Brassica rapa var. Rapa …

Exploring Interactions Of Phyllosphere Epiphytes With Plant Pathogenic Bacteria Pseudomonas And Xanthomonas On Tomato, Ashley D. Turner

Theses and Dissertations

Recent studies have indicated the importance of resident microflora of plants in contributing towards overall plant health. Among difference components of the plant microbiome, Methylobacterium and Sphingomonas have been recognized as common residents of the phyllosphere for many host plants, however their role in disease control needs to be further investigated. The purpose of this study was to conduct experiments investigating the effectiveness of phyllosphere Methylobacterium and Sphingomonas isolated from red clover against common tomato phyllosphere bacterial pathogens, Pseudomonas syringae pv. tomato and Xanthomonas perforans. Additionally, this study uses X. perforans wild-type and X. perforans type VI secretion system …

The Effects Of Seed-Applied Fluopyram On Root Penetration And Development Of Meloidogyne Incognita On Cotton And Soybean, Tracy Hawk

Graduate Theses and Dissertations

Plant-parasitic nematodes are major pests of cotton and soybean in Arkansas, and across the Southern United States. These nematodes cause more than $3 billion worth of crop losses each year, in part due to lack of available control tactics, such as nematicides. Fluopyram has recently been registered as a seed-treatment nematicide in agronomic crops. The toxicity of fluopyram against Meloidogyne incognita infection has been reported, however, information on root protection provided by fluopyram against Meloidogyne incognita is lacking. The first objective of this research was to evaluate the effect seed-applied fluopyram had on nematode development, root galling, and reproduction on …

Mining For Biological Control Agents Against B. Glumae, The Causal Agent Of Bacterial Panicle Blight Of Rice., Katherine Anne Wilkinson

Graduate Theses and Dissertations

Burkholderia glumae is the causal agent of the emerging disease, Bacterial Panicle Blight of rice, a serious disease that can significantly decrease yield and poses a threat to rice production worldwide. This thesis is concerned with searching for a biological control agent to control this disease. Plant associated microbes are a good source of beneficial bacteria which can be exploited for use as a biological control agent. It is possible that the microbiomes of cultivars which are known to be more resistant to plant pathogens may contain more microbes which inhibit those pathogens and therefore could be used as biological …

Occurrence Of Putative Endornaviruses In Non-Cultivated Plant Species And Characterization Of A Novel Endornavirus In Geranium Carolinianum, Rachel Herschlag

LSU Master's Theses

Endornaviruses are RNA viruses, which can infect plants yet cause no apparent symptoms. To date, most descriptions of endornaviruses infecting plants have been in cultivated species. A survey for endornaviruses in non-cultivated plants was initiated in 2015 and continued through 2017 in Baton Rouge, Louisiana. Two hundred and seven plant species were tested for distinctive dsRNA profiles by selective extraction and gel electrophoresis, of which seven contained endornavirus-like dsRNA. RT-PCR amplification of an endornavirus-specific sequence supported the endornavirus nature of six of the seven samples. Of the six host species, one species, Geranium carolinianum was confirmed as being infected with …

Use Of The Antibiotics, Streptomycin And Terramycin, As Growth Stimulants For Orchid Seedlings., Margaret W. O'Neill

Biology ETDs

Antibiotics first came to the public's attention in 1945, when penicillin and streptomycin were released by the United States government to fight human diseases. Later, other antibiotics were released and experimental work was done on control of plant and animal diseases. By 1948 plant pathologists found that certain plant diseases such as walnut blight, tomato and pepper bacterial spot, soft rot, cucumber, downy mildew, chrysanthemum bacterial wilt, and lilac bacterial blight could be controlled by antibiotics.