Index Catalog // ScholarsArchive@OSU

Creator:: Gent, David H., Claassen, Briana J., Twomey, Megan C., Wolfenbarger, Sierra N., and Woods, Joanna L.
Abstract:: In the Pacific Northwestern United States, the hop powdery mildew fungus, Podosphaera macularis, survives overwintering periods in association with living host tissue because the ascigerious stage of the pathogen is not known to occur in this region. Field experiments were conducted over a 5-year period to describe the overwintering process...
Resource Type:: Article

Creator:: Woods, Joanna L., Dreves, Amy J., Fisher, Glenn C., James, David G., and Gent, David H.
Resource Type:: Conference Proceeding

Creator:: Wolfenbarger, Sierra N., Massie, Stephen T., Ocamb, Cynthia, Eck, Emily B., Grove, Gary G., Nelson, Mark E., Probst, Claudia, Twomey, Megan C., and Gent, David H.
Abstract:: Host resistance, both quantitative and qualitative, is the preferred long-term approach for disease management in many pathosystems, including powdery mildew of hop (Podosphaera macularis). In 2012, an epidemic of powdery mildew occurred in Washington and Idaho on previously resistant cultivars whose resistance was putatively based on the gene designated R6....
Resource Type:: Article

Creator:: Gent, David H., Probst, Claudia, Nelson, Mark E., Grove, Gary G., Massie, Stephen T., and Twomey, Megan C.
Abstract:: Canopy management is an important aspect of control of powdery mildew diseases and may influence the intensity of fungicide applications required to suppress disease. In hop, powdery mildew (caused by Podosphaera macularis) is most damaging to cones when infection occurs during bloom and the juvenile stages of cone development. Experiments...
Resource Type:: Article

Creator:: Scott, Jason B., Gent, David H., Hay, Frank S., and Pethybridge, Sarah J.
Abstract:: Flower number is the primary determinant of yield in pyrethrum (Tanacetum cineariifolium). Traditional estimates of flower numbers use physical harvesting of flowers, which is time consuming, destructive, and complicated. The precision of flower number estimates may be highly influenced by spatial heterogeneity of plant density and vigor. Here, we examined...
Resource Type:: Article

Creator:: Summers, Carly F., Gulliford, Colwyn M., Carlson, Craig H., Lillis, Jacquelyn A., Carlson, Maryn O., Cadle-Davidson, Lance, Gent, David H., and Smart, Christine D.
Abstract:: RNA sequencing (RNA-seq) and genotyping-by-sequencing (GBS) were used for single nucleotide polymorphism (SNP) identification from two economically important obligate plant pathogens, Pseudoperonospora cubensis and P. humuli. Twenty isolates of P. cubensis and 19 isolates of P. humuli were genotyped using RNA-seq and GBS. Principle components analysis (PCA) of each data...
Resource Type:: Article

Creator:: Summers, Carly F., Adair, Nanci L., Gent, David H., McGrath, Margaret T., and Smart, Christine D.
Abstract:: Real-time PCR assays using locked nucleic acid (LNA) probes and high resolution melt (HRM) analysis were developed for molecular differentiation of Pseudoperonospora cubensis and P. humuli, causal agents of cucurbit and hop downy mildew, respectively. The assays were based on a previously identified single nucleotide polymorphism (SNP) in the cytochrome...
Resource Type:: Article

Creator:: Gent, David H., Twomey, Megan C., Wolfenbarger, Sierra N., and Woods, Joanna L.
Abstract:: Optimum timing and use of fungicides for disease control are improved by an understanding of the characteristics of fungicide physical mode of action. Greenhouse and field experiments were conducted to quantify and model the duration of pre- and postinfection activity of fungicides most commonly used for control of hop downy...
Resource Type:: Article

Creator:: Nelson, Mark E., Gent, David H., and Grove, Gary G.
Abstract:: Results of 28 field trials conducted over a 12-year period investigating management of hop powdery mildew caused by Podosphaera macularis were quantitatively summarized by meta-analysis to compare product efficacy and use patterns by mode of action as defined by Fungicide Resistance Action Committee (FRAC) groups. Availability of original observations enabled...
Resource Type:: Article

Creator:: Hay, Frank S., Gent, David H., Pilkington, Stacey J., Pearce, Tamieka L., Scott, Jason B., and Pethybridge, Sarah J.
Abstract:: In Australia, pyrethrum (Tanacetum cinerariifolium) is affected by a foliar disease complex that can substantially reduce green leaf area and yield. Historically, the most important foliar disease of pyrethrum in Australia has been ray blight, caused by Stagonosporopsis tanaceti, and other fungi generally of minor importance. Temporal fluctuations in the...
Resource Type:: Article

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