Kim Corella from Cal Fire has been heading up the search for Phytophora ramorum, the cause of Sudden Oak Death (SOD). She shared the 2017 SOD BLITZ results for SLO County, noting enormous participation with 289 trees sampled! Kim wanted to thank everyone who participated in this year SOD BLITZ. She notes that we were very concerned about gathering more samples in 2017 to determine the extent to which SOD was in SLO County, and is happy to report that 2017 SOD BLITZ was all negative, Apparently the 2016 SOD BLITZ survey showed false positives. The 2017 SOD BLITZ samples were tested by two completely different DNA tests and also by trying to culture out the pathogen on specialized agar.
Streamside samples at speciﬁc streams in the county showed San Carpoforo creek positive for SOD for the second time. It was found positive in 2012 the year the drought began and again this year. P. ramorum was cultured out on specialized media for these samples by UC Davis, which means the physical pathogen is present on the media. This creek watershed begins in Monterey County and additional surveys along San Carpoforo creek will take place next spring to determine if the positive is coming from SLO County or from Monterey County. Since we don’t know the origin of infested plants that are allowing the stream to be positive, we can’t say that SOD is in SLO County.
Many thanks to Lauren Brown for heading up the CNPS end.