Phytophthora ramorum Threatens the California Nursery Industry
In 1995, tan oaks and other oaks were observed to be declining in Marin County, California near a trailhead at Mt. Tamalpias. Lesions and weeping cankers were observed on some trees. The decline remained a mystery until Phytophthora ramorum was cultured from some of the trees in 2000. The pathogen was detected in several natural habitats in 12 Northern California counties. In some counties, the organism was wide spread while in other counties, it was found to be in one or two isolated areas, far from commercial nurseries. In the fall of 2001, the disease had only been detected in one nursery in the entire state. This nursery was located in the middle of a native forested area, including a canopy of tan oaks and California bay laurel trees. The nursery grows mostly host material including several hundred varieties of Rhododendrons. It was later learned that bay trees serve as a source of inoculum for P. ramorum. This location also has substantial amounts of rain in the winter months. In short, this is a perfect environment for P. ramorum. In February 2002, the decision was made to quarantine the entire 12-county area rather than delimit the areas of actual infestation within each county. A year later, in Marin County in May 2003, P. ramorum was detected in a second nursery. This nursery was located in a valley where trees that were infected with P. ramorum could be seen on the hillsides above. The nursery owners had agreed a few years earlier to allow a forest pathologist to do an experiment in their growing grounds. The scientist purchased oak trees and infected them with P. ramorum, and placed them on the nursery property. Two years later, detection was made on host material in the nursery, which were located under bay trees. It was not determined whether or not the infection came from the native vegetation on the hillside or from the infected oak tree experiment. It should be noted, when not taking into account any trace forwards from other nurseries, these two nurseries remain the only two nurseries in the 12 quarantined counties to ever have P. ramorum detected in the nursery. In spring of 2003, a nursery in Stanislaus County had a detection of P. ramorum in Camellia. The nursery destroyed several thousand plants, according to the United States Department of Agriculture (USDA) guidelines under the quarantine, and the nursery is now certified free of the disease. In March 2004, P. ramorum was detected in two nurseries in Southern California during survey work being done by the California Department of Food and Agriculture (CDFA) as part of the National Nursery Survey. The smaller nursery turned out to be a positive find as a trace forward from the larger nursery. The larger nursery ships host material to many states and Canada. The nursery is now in the process of having P. ramorum delimited and will follow USDA guidelines to eradicate the disease. Results from trace forwards have yielded, not surprisingly, positive finds by some states. In summary, although the pathogen was thought to have been in California since 1995, or perhaps many years prior to that, there have been a total of only four nurseries to date that have had detections not involving trace forwards. Portions of the current USDA protocol were designed to prevent the movement of P. ramorum through the nursery pathway. The federal domestic regulation (7 CFR 301.92-11) was thoughtfully developed by regulators with input from scientists and stakeholders through multiple meetings and public hearings. This disease has not spread very rapidly in nurseries in the 12-county quarantine area in several years, and points to the success of the current USDA protocols to limit the spread of this disease through the nursery pathway. Recent Developments The discovery in early March 2004 of Phytophthora ramorum at two California nurseries has been used as an excuse by some states to close their borders to some or all California nursery plants. As of now, states have imposed their own restrictions, and USDA has failed to enforce a national standard, as required by federal law. The evidence is overwhelming that states are basing their restrictions solely on the economic protectionism. At least four states-Florida, Kentucky, Louisiana and West Virginia-have banned all plants from California, even those that cannot spread the disease. In addition, the states have imposed bans on plant material coming from areas that have already been under quarantine. The safeguards that were sufficient previously are apparently inadequate at this time. Congress passed the Plant Protection Act to preempt inconsistent state laws and demanded adherence to sound science, but this provision is meaningless if USDA refuses to use it. On March 26, USDA announced a statewide quarantine on all host and associated host plants, a drastic action given that only two nurseries tested positive in the survey of southern California. Nevertheless, this action offered the opportunity to prove that a nursery was "SOD Free" and therefore, able to ship. In fact, this action meant that nurseries within the boundaries of the original quarantine could continue operating as they have since 2002. Despite the March 26 announcement, USDA has yet to implement this rule. Meanwhile, the rogue states continue to advocate USDA action far beyond what the science may justify and those states continue with their ban on California plants. To get information on state restrictions, find the host list and read more about Phytophthora ramorum, go to the CDFA website at www.cdfa.ca.gov. Request for Industry Support This urgent message is to all segments of the nursery industry. The March 2004 find of Phytophthora ramorum in a large Southern California nursery, which ships nationwide, has sent shock waves through the nursery industry throughout the United States. Prior to this recent find in Southern California, a federal quarantine already existed in 12 Northern California counties for P. ramorum, the agent linked with the death of some oak trees in forests in California. This United States Department of Agriculture (USDA) quarantine was designed to prevent the spread of this disease through the nursery pathway and highly regulates this disease using scientific principals. In March, USDA regulations, in addition to the existing quarantine, were established causing confusion within the state at the retail level of what host material is "safe" to purchase for the nursery. Customers at retail stores have also been misled by the media coverage and are uncertain about the risk of spreading the disease by buying certain host plants. In addition, some states have placed various forms of quarantine on California nursery stock, some have banned all nursery stock from California from being shipped into their states, including all non-host material. Many entities such as CDFA, USDA and your nursery leadership view the actions of these "rouge states" illegal under federal law. A very dangerous precedent could be set if other states such as Florida were permitted to impose stricter rules on California than those already established by USDA. Your CANGC staff, volunteer leadership and consultants have been working overtime to address these threats to the California nursery industry. Multiple conference calls with USDA and CDFA officials, as well as those with industry representatives, have been occurring daily for weeks. In addition, unanticipated utilization of CANGC's attorneys, public relation consultants, and lobbyists have created the need for additional financial resources. Our spring is at risk. The time to act is now. We encourage members of the nursery industry to contribute what they can to these efforts. Every dollar will be spent to keep California nursery stock moving and to get the public the truth about P. ramorum. We need your help on the many fronts to fight this assault on our industry. Time is of the essence. Thank you for your consideration in this very serious matter. We would like to say "Thank you!" to all those who have already responded to this request. Sincerely, Don Dillon Jr., Chairman of the Board California Association of Nurseries and Garden Centers
Dave Fujino, Executive Grower Member Director To pledge to the Sudden Oak Death/Phytophthora ramorum fund Online click here Checks can also be mailed to:CANGC/SOD FUND 3947 Lennane Drive, Suite 150 Sacramento CA 95834-1973 Make payable to CANGC (reference SOD on the "Memo" line)
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