St. Paul, Minn. (August 28, 2001)—It’s not a pretty sight but it’s one that, sadly enough, is becoming increasingly common to some of California’s most scenic coastal counties. Thousands of beautiful, stately oak trees have died, or are dying, from a new disease never seen before in the U.S. What’s more, the disease, now called Sudden Oak Death, appears to infect more than just oak trees and scientists are worried that they may have an emerging epidemic on their hands. At the upcoming annual meeting of the world’s largest organization of plant health scientists, researchers will unveil the findings of the first major study on the effects of this devastating new disease.
“To say we’re concerned is an understatement,” states David Rizzo, a plant pathologist with the University of California in conjunction with the USDA Forest Service and author of the research that will be presented at the meeting. “It was just last year that researchers finally gave this disease a name. That’s how new and unknown it is.” Having recently discovered that the disease had spread from California to Oregon, researchers begin to wonder whether eastern oak trees would be susceptible to the disease as well, should it find it’s way out of the west coast and move eastward.
To find out, Rizzo and his colleagues grew two eastern oak species in greenhouses and infected them with the fungus that causes the disease. Their results confirmed their fears. The eastern oaks were just as, if not more, susceptible to the disease. States Rizzo, “Since we have yet to even understand how this disease works it terms of how it’s spread, we have no idea just how great a problem it might create for oak forests in this country.” Add to this the fact that the disease seems to attack other plants as well, like rhododendron, and the potential for the spread of the disease seems even more alarming.
Rizzo stresses however that his research is only the first of many studies currently being done. And, because trees grown in greenhouses (like the ones used in his study) can react to infectious diseases differently than those in a natural forest, or even in an urban setting, his research does not necessarily mean that eastern oaks will succumb to the disease in the same way that the California oaks have. Adds Rizzo, “We suspect that there are other factors at work that have made California oaks particularly vulnerable to this disease, like the weather patterns along the coastal forests for example.”
But until they know more, plant health scientists prefer to err on the side of caution, respectful of the unknown potential of this new disease while hopeful that their research will eventually shed some light on how to control it. States Rizzo, “We’re not saying this is the next Dutch elm disease, but we are stressing the need for research support. We need to do more work like the project we just completed if we are to stay one step ahead of what appears to be a pretty aggressive disease.”
Rizzo will present the results of his research at the APS Annual Meeting in Salt Lake City, Utah starting at 12:00 noon on Tuesday, August 28. Additional information on this topic is also available at www.suddenoakdeath.org. Complimentary registration is available for reporters and science writers. The American Phytopathological Society (APS) is a nonprofit, professional scientific organization dedicated to the study and control of plant diseases, with 5,000 members worldwide.