How often do you administer phosphonate to oaks to help protect them from sudden oak death?

Phosphonate injection treatments to help prevent sudden oak death infection of susceptible oak species (coast live oak; California black oak, Shreve’s oak, and canyon live oak), if applied in the fall (after October 30th ), need only to be applied once every other year (biannual frequency). If your first phosphonate treatment is in the spring, then […]

How can I be sure I’m not spreading SOD with my tools?

The most important part of ensuring that tools will not spread SOD is to be sure that no organic debris or soil is present on the tools. This applies to all portions of each tool, including parts that may not be visible (like the return of a chain in a chainsaw or the interior of […]

How do I determine the distance from trees on my property to P. ramorum-positive trees on SODmap?

When looking at SODmap, you may wonder if P. ramorum-positive trees are close enough to pose a threat to trees on your property. Use the free App SODmap mobile to get the answer. Just tap the App risk function and it will tell you whether  infected trees trees are within 200 m (high risk) or […]

I have a very small bay tree that has leaves with P. ramorum symptoms. Should I just remove the tree or take a sample first?

It is always advisable to first have a tree tested before removal to be sure P. ramorum is present.  If you are noticing symptoms in spring, attend a nearby SOD Blitz for information on sampling and lab submissions.  For more information, go to sodblitz.org.

I just cut down a small infected bay. Do the root shoots carry P. ramorum?

Bay shoots do not carry P. ramorum because the pathogen is not systemic in bay.  Each leaf is infected independently. Additionally, there is no root infection in most P. ramorum hosts,  particularly California bay laurel.  However, when bays re-sprout, they may be re-infected.  

Does rain affect preventative phosphite (e.g. Agri-Fos®) treatments for oaks?

When treating oak trees with phosphites to help prevent SOD, it may be beneficial to apply the topical treatment to bark that is dry.  Rain occurring after the treatment (even immediately after) does not affect the application. If injecting phosphites, it may be better to avoid rainy days, as lower evapotranspiration is often documented for […]

I have an oak in the Bay Area that is oozing liquid from the trunk base. Should I test it for SOD? If so, how?

When trying to determine if an oak may have SOD (caused by the plant pathogen Phytophthora ramorum), the first step is to determine if the tree lies within 1 km of a known outbreak.  This can be done by accessing SODMAP at www.sodmap.org or by uploading the free “SODMAP Mobile” app to your smartphone.  Stand next to […]

How long can Phytophthora ramorum survive in wood chip mulch?

Survival of P. ramorum (SOD pathogen) in wood chips depends on a few factors: Were the chips allowed to become wet? What size are the chips? Is green waste present? What time of year was the wood chipped? Where in California are the chips located? Chips that are piled wet or tarped and include infected […]

How long can Phytophthora ramorum survive in soil moved from an infested area?

Survival of P. ramorum (SOD pathogen) in dead hosts or non-plant substrates is extremely variable and strongly affected by climatic factors. Although a comprehensive study on this topic has not conducted, extrapolating from several studies we can say the following: Soil becomes more infectious from late winter to early summer in the presence of rainfall, […]

When will the 2016 SOD Blitz and training sessions be held?

SOD Blitzes include a training session for blitz volunteers on SOD and proper sampling, followed by time in the field  for collecting and marking sample locations. All necessary collection materials are provided to volunteers during the training session for use either the same day of the training or the day after. All samples are to […]

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