Phytophthora ramorum
Trials of silvicultural methods for treating "P. ramorum" began in Humboldt County in northwest coastal California in 2006. The trials have taken place on a variety of infested properties both private and public and have generally focused on varying levels and kinds of host removal. The largest () and most replicated trials have involved removal of tanoak and bay laurel by chainsaw throughout the infested stand, both with and without subsequent underburning designed to eliminate small seedlings and infested leaf litter. Other treatments included host removal in a modified “shaded fuelbreak” design in which all bay laurel is removed, but not all tanoaks; bay and tanoak removal using herbicides; and removal of bay laurel alone. The results of these treatments are still being monitored, but repeated sampling has so far detected only very small amounts of "P. ramorum" in the soil or on vegetation in the treated sites.
Phytophthora rubi
Phytophthora rubi is the principal cause of root rot in red raspberry. Originally classified as a variant of "P. fragariae" some now consider it a distinct species. This organism has been isolated from raspberries in Europe, North America, Chile, and many other countries around the world. It is best controlled through a combination of good management practices and use of resistant varieties. It is a significant cause of crop loss in poor draining soils.