We envision a resilient world dependent on the thoughtful cultivation of plants

Laboratory Report

Articles: Laboratory Report

Foliar and Canker Hosts
We have learned a lot about sudden oak death (SOD) and its causative agent, the water mold Phytophthora ramorum (P. ram), since our last report (see Pacific Horticulture, October ’04). Many of us are now aware of the central role played by California bay laurel (Umbellularia californica), a foliar host that provides an ideal environment for P. ram to reproduce. Foliar hosts produce the spores that are responsible for spreading SOD; some, such as Rhododendron, Camellia and Pieris, may be killed by P. ram. Without suffering significant damage, bay laurel acts as a primary driver of the disease, for several reasons: it produces copious quantities of spores, it frequently overtops oaks and spores are literally “rained down” on oak canopies, and it is ubiquitous in many woodlands, where it grows in close association with susceptible oaks.

Canker hosts include several tree species in the red oak group (Quercus spp.), and tan oak (Lithocarpus densiflorus), which is unique in acting as both a foliar and canker host. Canker host species generally do not produce spores that spread the disease, but suffer varying levels of mortality. While several species of red oa...

READ THE WHOLE STORY


Join now to access new headline articles, archives back to 1977, and so much more.

Enjoy this article for FREE:

Articles: Calochortophilia: A Californian’s Love Affair with a Genus by Katherine Renz

If you are already a member, please log in using the form below.

Share:

Facebook
Twitter
LinkedIn

Social Media

Garden Futurist Podcast

Most Popular

Videos

Topics

Related Posts

Welcome, Greywater, to the Garden

Summer 2022 Oh, summer: delightful warm air, tomatoes swelling on the vine, fragrant blooms on an evening stroll. When it’s warm and rainless, how is

Powered By MemberPress WooCommerce Plus Integration

Your free newsletter starts here!

Don’t want to see this pop-up? Members, log-in here.

Why do we ask for your zip code?

We do our best to make our educational content relevant for where you garden.

Why do we ask for your zip code?

We do our best to make our educational content relevant for where you garden.

The information you provide to Pacific Horticulture is NEVER sold, shared, or rented to others.

Pacific Horticulture generally sends only two newsletters per Month.