page_title: Podosphaera macularis
section_title: Host range and symptoms of Podosphaera macularis
hierarchical_section_title: Podosphaera macularis / Host range and symptoms of Podosphaera macularis
caption_attribution_description: English: Signs and Symptoms of Powdery Mildew on Hop Leaves
context_page_description: Podosphaera macularis is a plant pathogen infecting several hosts including chamomile, caneberrie, strawberries, hop, hemp and Cineraria. It causes powdery mildew of hops.
context_section_description: The pathogen that causes powdery mildew of hops was once considered to be Sphaerotheca macularis, which is capable of infecting many plants; however, in recent years, the pathogen that causes powdery mildew of hops has been taxonomically classified as Podosphaera macularis. This ascomycete is only pathogenic on hop
  plants, including both ornamental and wild hops. The host range of many Podosphaera macularis strains is restricted by the existence of resistant hop varieties, such as the “Nugget” variety of Washington state and Oregon, although in recent years, resistance
  within this hop variety has been overcome in the laboratory. When disease does occur, early symptoms include chlorotic spots on the leaves of hop plants. Spots may fade to gray or white as the season progresses. Signs include white clusters of hyphae, which are often present on the leaves, and in some cases can infect the cone itself. If this infection occurs, a brown, necrotic lesion may develop. Occasionally, chleistothecia are visible as small, black dots on the undersides of leaves.
caption: Signs of Powdery Mildew on Hop Leaves
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