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SOD Update

October 26, 2010

The San Francisco Chronicle recently published an update  about Sudden Oak Death (SOD) that was both misleading and inaccurate.

The article inaccurately claimed that “the mysterious pathogen…has killed tens of thousands of oak trees from Big Sur to southern Oregon.”  This is a gross underestimate of the number of trees that have been killed by SOD.   The California Oak Mortality Task Force reported in the announcement of their 2009 annual symposium that “Since the 1990s more than a million oak and tanoak trees have died from this pathogen and at least another million are infected.”  Since there is no known cure for the disease, we must assume those trees will die. 

Hillside in Big Sur, Wikipedia Commons

Secondly, the article quotes Matteo Garbelotto of UC Berkeley—who is described as “the nation’s foremost expert on sudden oak death”—as recommending that “homeowners in infected areas can remove bay trees…[to] increase the survival rate of nearby oaks.”   We doubt that this is an accurate quote because it is not consistent with the advice Garbelotto gave at one of his SOD workshops. 

One of the many professional gardeners attending that workshop asked if he should remove the bays in the gardens in which there are also oaks to protect the oaks from infection.  Mr. Gabelotto’s response was that the bays would resprout ten-fold and that the immature leaves of the resprouts would be more susceptible to infection than the mature leaves.  The gardener asked if he could prevent resprouts with Roundup.  Mr. Garbelotto replied that Roundup would not prevent resprouts. 

In other words, removing bay trees is easier said than done.  Attempts to do so can result in even more bay trees unless toxic chemicals such as Garlon are used repeatedly to prevent resprouts.  Since the immature leaves of the resprouts are more susceptible to SOD infection, this is not a wise strategy.

Garbelotto may have told the Chronicle that removing bay trees already infected with SOD may prevent the spread of the pathogen to oaks.  Although it seems to us a risky strategy, it is apparently being done in the Santa Cruz Mountains, according to the San Jose Mercury (“’Sorry baby, but you gotta go’,” December 17, 2009).  This is an important distinction:  removing healthy bay trees is likely to do more harm than good, while removing infected bay trees may make some sense, although we would prefer to avoid the use of toxic chemicals.   

Journalism is a powerful tool that can strengthen democracy if used responsibly, reporting the facts faithfully and balancing competing opinions when necessary.  The author of this article grossly underestimates the number of native trees killed by SOD and offers bad advice about killing healthy trees.  Those who still subscribe to the dwindling San Francisco Chronicle will not be surprised by such sloppy journalism.  It is an example of the death throes of the Bay Area’s local newspaper.

4 Comments leave one →
  1. October 27, 2010 4:06 am

    One other point in the SF Chron report deserves clarification. It says, “Oak trees also can be sprayed with phosphonate, which has proved to be effective against the disease.” This may give the impression that large-scale forest-wide spraying is possible to achieve a cure.

    According to Mr Garbelotto’s research on the subject, trees have to be individually treated. The phosphonate (together with a surfactant to enable bark penetration) must be applied to each tree: “The lower 10 feet of trunk must be thoroughly wetted, possibly including some of the lower main branches in the canopy.”

    The alternative is to *inject* the tree with the phosphonate.

    http://californiaagriculture.ucanr.org/landingpage.cfm?article=ca.v063n01p10&fulltext=yes

    The paper recommends re-treatment every two years; phosphonate is a treatment and not a cure. It’s best used protectively on healthy trees, especially when others nearby are infected.

    Webmaster: Good catch, SaveSutro! Having attended Garbelotto’s workshop, we can confirm that the SOD treatment he recommends is very labor intensive. He acknowledged that it is not realistic to use this treatment on wildlands, but rather on individual specimen trees in private gardens. As you say, this is not a cure, but rather a means of boosting the tree’s defenses against infection.

  2. November 3, 2010 11:16 pm

    Some relevant analysis I wrote to activists in March, 2009:

    I have been bringing up Sudden Oak Death Syndrome frequently of late as I used to mid-90s. It shows up along coastal areas of CA specifically in areas where vineyards have gone in (or been around). Right alongside the water-intensive vineyards started taking over coastal CA, in the early 90s, oaks in corresponding areas started suffering drought conditions. Weakened, they were showing up with what came to be called SODS. We (Sonoma Pesticide Alert) were making the connections at least by the mid-90s.

    I bring it up now, as we have seen Ojai under great attack with the excuse given that the state is concerned about the oaks. They have convinced average people to speak out on behalf of the pesticides program by convincing them that the Gypsy Moth is threatening them with loss of these majestic trees which are the landscape of Ojai. I fully expect that we are going to be hearing news reports about SODS dangers. But we must listen, because of course their answer is pesticides. As usual. So here is what I expect to be happening soon:

    The state (sometimes via university profs) will go into any area dotted with oaks (all our coastal areas) and start doing their disinformation campaigns about the poor oaks being endangered and weakened by the Gypsy Moth (under attack, they are likely to say) and then drone on and on about those same oaks or other oaks also being under attack from SODS. It’s a perfect way to make people feel afraid, and hopeless and feeling there is no alternative. It’s a brilliant chess move, sort of like their saying, “If you don’t let us use this chemical, we’ll have to use that chemical instead.” They are threatening to use Carbaryl. Please go to the middle column of our homepage, by the bottom and click on “pesticide poisoning accounts” to read about Carbaryl (.http://www.Don’tSpray California.org/) No, you don’t want to live through what I have with Carbaryl. On the other hand, you don’t want to live through other toxic pesticides.

    Max Ventura

Trackbacks

  1. Losing Battles « A Million Trees
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