In California, P. ramorum is primarily a leaf pathogen and thrives in coastal tanoak/redwood forests and oak woodlands. There are two categories of hosts for P. ramorum....
[From the December 2016 issue of the UC IPM Green Bulletin]
A new plant pathogen in the genus Phytophthora (pronounced Fie-TOF-ther-uh) has recently been found in several California native plant nurseries and habitat restoration sites. The pathogen, Phytophthora tentaculata, poses a risk of disease in wildlands, gardens and landscapes that use susceptible California native and non-native plants. Once introduced in these areas, the pathogen can generate disease for years to come, potentially causing lasting environmental and economic.../span>
- Author: Jeannette E. Warnert
Central Coast residents, officials, ranchers and representatives of conservation organizations came out in force to a November UC Cooperative Extension meeting sounding an alarm about the recent detection of Sudden Oak Death (SOD) in San Luis Obispo County trees, reported Kathe Tanner in the San Luis Obispo Tribune.
This was the first such gathering in this county since tests confirmed that the disease made its way south of Monterey County, according to event coordinator Mary Bianchi,...
- Author: Igor Lacan
[From the August 2016 issue of the UC IPM Green Bulletin]
Two “sap flux” diseases observed in landscape trees—bacterial wetwood (or slime flux) and alcoholic (“foamy”) flux—often trigger demands that a landscaper “do something.” Yet the most appropriate action may be to provide cultural care and to monitor for any additional problems rather than to apply chemicals or undergo drastic “tree surgery.”
A single wound or bark crack located on the trunk or a large branch.../h3>/span>
Drought is decreasing but not defeating the pathogen that causes sudden oak death, according to a citizen science-assisted survey conducted this spring by a UC Agriculture and Natural Resources forest pathologist.
Results of the 2015 Sudden Oak Death Blitz survey reveal coastal mountain infestations in areas such as Big Sur (19% infection), the Santa Cruz Mountains (13% infection), and western Sonoma County (12% infection) remain high despite an overall decline in infection rates from 4.4% to 3.7% across California's 15 infested counties.
Sudden oak death (SOD) symptoms have been seen in Alameda, Contra Costa, Humboldt, Lake, Marin, Mendocino, Monterey, Napa, San Francisco, San Mateo, Santa Clara, Santa Cruz, Solano,...