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Sudden Oak Death And Ramorum Blight, Marion Murray, Ann Mull

All Current Publications

Sudden oak death (SOD) and ramorum blight are caused by Phytophthora ramorum, a non-native water mold (oomycete) that originates from parts of Asia. Sudden oak death was given its name due to the appearance that entire trees were dying in just 2 to 4 weeks. In reality, the disease progresses over an extended period, estimated at more than 2 years after initial infection. Ramorum blight is nonlethal, typically causing foliar browning and wilting. This fact sheet discusses impact, damage and symptoms, plant hosts, disease cycle, and management.

Evaluation Of Bell Pepper Cultivars With And Without Resistance To Bacterial Leaf Spot And Phytophthora, West Central Minnesota, Nathan Dalman, Steve Poppe

Midwest Vegetable Trial Reports

Bacterial leaf spot (BLS) and Phytophthora (PHY) diseases are a common problem for Minnesota bell pepper producers and if not detected and treated early enough, these diseases can kill the plants. There are cultivars that have resistance to these particular diseases but these cultivars must maintain yields similar to traditional cultivars in order to be desired by producers and buyers. Our goal was to determine any differences in performance between cultivars with and without resistance. Yield, fruit size and number of fruit per plant were the evaluated characteristics.

Pseudomonas And Burkholderia Inhibit Growth And Asexual Development Of Phytophthora Capsici, Amena Khatun, Tarin Farhana, Abdullah As Sabir, Shah Mohammad Naimul Islam, Helen M. West, Mahfuzur Rahman, Tofazzal Islam

Faculty & Staff Scholarship

The objective of this study was to isolate and characterize antagonistic rhizobacteria from chili against a notorious phytopathogen Phytophthora capsici. Among the 48 bacteria isolated, BTLbbc-02, BTLbbc-03, and BTLbbc-05 were selected based on their inhibitory activity against P. capsici. They were tentatively identified as Burkholderia metallica BTLbbc-02, Burkholderia cepacia BTLbbc-03, and Pseudomonas aeruginosa BTLbbc-05, respectively, based on their 16S rRNA gene sequencing. All inhibited the growth of P. capsici at varying levels by inducing characteristic morphological alterations of P. capsici hyphae. The cell-free culture supernatant of all three isolates impaired motility (up to 100%) and caused lysis …

Characterization Of A Novel Clade Of Transporters In Phytophthora, Stephanie Padula, Paul F. Morris Dr, Howard Casey Cromwell Dr., Menaka Ariyaratne, Andrew Wagner

Honors Projects

The oomycete Phytophthora parasitica has a worldwide distribution and is an economically important pathogen of more than 100 species⁴. RNA-seq analysis showed that one gene, PPTG_16698 has the 5^th highest level of expression of all transport proteins in the zoospore stage, and is highly conserved throughout Phytophthora species. This project attempts to characterize the important biological role that PPTG_16698 plays in P. parasitica and other oomycetes. Three strategies have been implemented to accomplish this goal: growth analysis by heterologous expression in yeast, metabolite analysis in yeast, and construction of a GFP fusion protein to enable localization of …

Sampling And Testing For Plant Pathogens, Aileen Reid

Bulletins 4000 -

There are many methods used in the laboratory to determine whether Phytophthora or other fungi are present in growing media, water supply and diseased plants. These include:

• filtering water for spores

• baiting for fungi in growing media and water samples

• examining diseased plant tissue microscopically

• direct culturing from roots and other plant parts to isolate the fungal pathogen in pure culture.

This bulletin outlines some of the procedures involved. Growers may be able to do some basic baiting of soil or water samples themselves to alert them of a problem but the procedures involved in isolating …

Diseases Of Waxflower And Their Control, Aileen Reid

Bulletins 4000 -

Waxflower is susceptible to a range of diseases. This outlines the main problems which occur in commercial plantations and presents measures to control them. Since chemicals for control of plant diseases are constantly changing, growers are advised to seek the latest available information.

Nf02-518 Management Of Phytophthora Diseases Of Soybeans, Loren J. Giesler, Jane A. Christensen, Christopher M. Zwiener

University of Nebraska-Lincoln Extension: Historical Materials

Phythophthora diseases of soybean, caused by Phytophthora sojae, are present wherever soybeans are grown in Nebraska. The pathogen survives primarily as "resting" spores in the soil or in association with infested crop debris. Symptoms associated with Phytophthora sojae, infections include seed rots, pre- and post-emergence dampin goff of seedlings and stem rot of plants at various growth stages.

Knowledge of the races present in the state and how varieties with different resistance genes have performed in a grower's field is critical to variety selection for maximum profitability.

Nf00-411 Seed Treatment Fungicides For Soybeans (Revised January 2004), Loren J. Giesler

University of Nebraska-Lincoln Extension: Historical Materials

The most common soybean disease problem in Nebraska is seedling damping off and seed rot caused by several fungi. Early season damping off and root rots are often followed by premature death, which in many instances may be attributed to fungal infections earlier in the season.

This NebFact discusses the seed treatment fungicides for soybeans. These includes protectants (contacts) that are effective only on the seed surface; and systemic fungicides that are absorbed by the emerging seedling, which inhibit or kill the fungus inside host plant tissues.

G89-900 Phytophthora Root Rot Of Alfalfa, John E. Watkins, Fred A. Gray, Bruce Anderson

University of Nebraska-Lincoln Extension: Historical Materials

Disease cycle, symptoms and management practices for phytophthora root rot are discussed in this NebGuide.

Phytophthora root rot (PRR) is a major cause of seedling death in newly established alfalfa, and causes a progressive decline of established stands in Nebraska. This disease is caused by the fungus Phytophthora megasperma f. sp. medicaginis and occurs in most of the alfalfa producing areas in North America.

The Phytophthora that infects alfalfa is different from the Phytophthora that causes root rot in soybeans. Growers sometimes think the two diseases are the same for the respective crops, but they are two different diseases with …