Sudden Oak Death

GetFileAttachmentIdentified in Europe in the mid 1990’s and now found in California, Oregon, Washington and Canada, Sudden Oak death or SOD ( Phytophtera Ramorum) has been found to infect, damage and kill many of the native and imported Northwest landscape plants and trees we’ve grown to love right here in the Puget Sound region. This fungus-like pathogen is most easily transferred by free-flowing water into the roots of susceptible plants but also moves by wind, animal and human vector. Local nursery stock has recently been identified by WSDA as a source of infected plant material as it had been installed in homeowner landscapes and subsequently failed. Needless to say, the costs of plant quarantines, plant destruction or treatments have already had a large economic impact on the nursery industry. Many Maple varieties as well as Rhodies, Camellia, Viburnum, Madrone, Doug Fir, Laurel, Andromeda, Redwood, Cascara and, of course, many Red Oak varieties, are susceptible to SOD and the list is growing to over 70 known plant varieties. The potential impact of this pathogen on the typical Northwest landscape is hard to ignore. Having become aware of this storm on the horizon, we at Wolbert’s, Inc began looking for ways to help our clients identify conditions in their landscapes that were conducive to SOD infection such as poorly drained soil, over irrigation or the need for aged, aerified mulch under trees. It is often difficult to mitigate the conditions conducive to disease infection by mechanical means only, especially in a native species landscape setting where the goal is a natural environment, for example. To meet this impending challenge, we at Wolbert’s are now offering an SOD preventive treatment for susceptible trees and shrubs. The exciting thing about the material we have selected for this purpose is it’s multi-prong affect: It is a low-toxicity, phosphite-based, fungi-static (stops fungus growth), highly systemic (moves easily and quickly through the plant) material that is currently used world-wide in a variety of agricultural, landscape and forestry applications as a fertilizer element/ fungicide and most importantly, will trigger a Systemically Acquired Resistance (SAR) response in the plants it is applied to. This means that plants will automatically begin to thicken cell walls and produce proteins and acids necessary to fight off damaging pathogens and insects. These defense mechanisms are already in place in all plants but are brought to full alert by contact with these gentle phosphite molecules instead of a damaging disease pathogen. The result is a more robust, disease resistant plant relying more on its own biology and less on outside inputs. Here are good links to other sites providing more information about Sudden Oak Death and Phosphite fungicide:

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Evan Ogden

Evan Ogden Senior Staff

Evan Ogden
Senior Staff