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....
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...
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...
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...
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...
Knowledge of processes leading to crop damage is central to devising rational approaches to disease management. Multiple experiments established that infection of hop cones by Podosphaera macularis was most severe if inoculation occurred within 15 to 21 days after bloom. This period of infection was associated with the most pronounced...
Impact and relevance are valued by both plant pathologists and
the supporters of research and extension. Impact has been characterized
as the “So what?” of research results, and in applied research
in agriculture typically involves some change in human
behavior. This might involve, for instance, avoidance of broad
spectrum pesticides,...