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Mr. Magnarelli is director of the Connecticut Agriculture Experiment Station (CAES), which is cooperating with the U.S. Department of Agriculture's Animal and Plant Health Inspection Service (APHIS) in minimizing the potential spread of the disease.
Sudden Oak Death, or SOD, is the biggest threat posed by the pathogen, a fungus called phytophthora ramorum. As it girdles an oak's trunk over several years, it induces canker sores until, near the very end, the tree quickly withers and dies.
Since 1995, SOD has killed, or required the extermination of, hundreds of thousands of oaks and tanoaks in the cool, misty coastal regions of central and northern California and southern Oregon, according to Katie Palmieri of the California Oak Mortality Task Force.
Whether the pathogen will thrive in Connecticut's very different climate is a scientific unknown at this point. Yet, state officials had hoped to avoid becoming a test case for SOD.
"The horse is out of the barn. It's been out of the barn for a long time," lamented Mr. Magnarelli. He said his agency was notified by the United States Department of Agriculture in late October that 10,000 rhododendron plants from a wholesaler in Oregon had entered Connecticut. He was not sure how the agency made the discovery, but said, "They knew about it since September. That's a long lag time."
An Oregon Department of Agriculture administrator, Dan Hilburn, confirmed that 13 growers in his state had tested positive in May for the pathogen and that it was a wholesaler, Hinds Nursery, which supplied Connecticut with the contaminated shipment.
At this time, neither CAES nor APHIS is releasing the names of the outlets here that received these plants.
APHIS has so far tracked 56 Connecticut sellers as having received potentially contaminated plants, but there may be more. "We have been in contact with them all and found out that in many cases the plants were all gone," Mr. Magnarelli said.
At outlets that still had plants on site, CAES and APHIS inspectors took samples, conducted preliminary tests and found multiple positive results. Of these, 14 tissue samples were sent to APHIS for DNA testing in Beltsville, Md., with confirmation Nov. 22 that five, from three outlets, had tested positive for the pathogen.
From this admittedly small sample size, Mr. Magnarelli said his agency estimated the rate of infection in the entire shipment to be one third, or roughly 3,300 plants.
The three outlets whose plants tested positive for the disease are awaiting permits from the state Department of Environmental Protection to allow them to transport and incinerate the remaining plants. Mr. Magnarelli said that, meanwhile, in accordance with USDA procedures, the rhododendrons have been quarantined.
The strategy for finding infected plants that have already been sold, as well as any oak trees that may become contaminated in the future, appears to involve education, outreach and monitoring, rather than any type of massive recall.
"A lot of these plants are probably O.K.," Mr. Magnarelli stressed.
Still, his agency is asking nursery and arborist associations to notify members about the introduction of the SOD pathogen, and it is encouraging gardeners, landscapers, loggers and others to be on the lookout for signs of the disease. Symptoms can include leaf and twig blight on host plants, and canker sores on oak trees-although such symptoms can also be caused by a variety of other diseases.
Not much is known about how phytophthora ramorum spreads. Most scientists theorize that airborne spores can spread during severe weather events, and can likely also be spread by rain splash and mechanical means.
To grow well, the fungus needs a cool, moist climate, such as exists in California's "fog belt."
Phytophthora ramorum also prospers in host-suitable shrubs, among them Connecticut's own state plant, the mountain laurel.
While trees outside of Oregon and California have never been found with SOD, the offending fungus reached 22 states this year from the interstate sale of nursery plants.
While the threat to forests has been ongoing, Ms. Palmieri pointed out that the disease has now secured a second front on which to wreck havoc: the nursery and growers industry. It has only been a recent phenomenon that commercially grown plants have been detected with the disfiguring disease.
"There's been a lot of tension," she said. "Everybody's scared of contracting the disease in their state-many stepped up with regulations above and beyond what the federal government required." And that, she said, has "created chaos."
Tim Profeta, counsel for the environment to U.S. Sen. Joe Lieberman, said that their office had been aware of the threat from the pathogen since April, and had pressed USDA for a better way to track plant shipments.
Asked whether it's too late to recover the plants that have been sold to landscapers and gardeners, he responded, "It's an awful situation but they've only been out there for a season. We've been talking to experts ... You can do something. There is a process by which you can try and contain it, but it will take the concerted efforts of the people of Connecticut working together."
Bob Heffernan, the executive director of Connecticut Green Industries-an umbrella organization that includes associations of florists, greenhouse growers and nursery and landscape businesses-is well aware of the threat.
"We've informed all of our members about what's going on," he said, recognizing that if the pathogen spreads, "a lot of the diseased or infected trees and shrubs are going to have be destroyed and a lot of it is going to be at our cost."
"The key is going to be the climate and whether it kills the fungus. We're just hopeful that's going to do it. ... If the fungus starts to adapt, of course, you've got a problem," said Mr. Heffernan, who is a resident of New Milford.
Even trickier, he added, is that "You can't diagnose [SOD] just by looking at it-and that's what makes it so difficult. And that takes time. It has to be sent out to Beltsville [the Maryland lab] and that take weeks."
Further complicating detection efforts is that the pathogen goes dormant during hot, dry spells, and cannot be detected on plants leaving grower's lots.
Mr. Magnarelli said he would like to see more federal regulation on the nursery industry. "Right now, it doesn't matter what states do. ... In my opinion, some form of bar-coding nationally is going to help a lot. Regulatory agencies trying to track down where these plants come from is difficult and [bar-coding] would make it much better.
Senator Lieberman's office is evaluating the possibility of legislation in 2005 that would mandate bar-coding on nursery plant containers.
In Connecticut, as in other states, right now, the wait is on and the hope here is for a mighty cold winter, with little cover of snow.
In addition to offering free preliminary tests for the disease at its New Haven facility to anyone with suspect plants, CAES will be looking for signs of SOD at its many forest test plots scattered throughout the state.
The number at CAES to call to report suspected cases of the pathogen or SOD is 203-974-8499. The COMTF Web site, www.suddenoakdeath.org, also provides a wealth of information about SOD, with reference photos and links.
