English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Hop downy mildew caused by the oomycete Pseudoperonospora humuli is primarily managed with fungicides because commercial varietal resistance is unavailable. Mefenoxam, a phenylamide-class fungicide, is highly effective for systemic disease control but is at high risk for the development of pathogen insensitivity. Due to the recent expansion of hop production in Wisconsin, it was unknown if P. humuli could be managed with mefenoxam because insensitivity has been documented in other regions. During 2015 to 2017, isolates of P. humuli were collected from commercial yards throughout Wisconsin. Isolates were screened for insensitivity using a leaf disk assay with fungicide-amended water agar. Insensitivity was determined using a single discriminatory dose of 25 μg/ml of mefenoxam, and isolates were considered insensitive if they exhibited at least 50% sporulation on amended media relative to nonamended water agar. Over all years, nearly 48% of all isolates were insensitive to mefenoxam. The incidence of insensitivity varied between individual hop yards, with most yards exhibiting a mixture of sensitive and insensitive isolates. At this time, mefenoxam-insensitive populations do not appear to be predominant in Wisconsin. Growers should monitor the effectiveness of mefenoxam applications in their hop yards and be responsive to changes in crop response.

Investigating Phenylamide Insensitivity in Wisconsin Populations of Pseudoperonospora humuli