Over the past 15 years, an invasive plant disease has left a patchwork of dead and dying trees in California's majestic coastal forests. But the loss of trees is changing more than just panoramic views: The number of ticks that can carry a disease that causes painful joint swelling, fatigue and even neurological damage is growing - a result of the gaps created in the forest when trees die, a recent study found.
To determine how the loss of trees affects ticks, their hosts and the Lyme disease they might carry, researchers at UC Berkeley, UC Santa Barbara and the Cary Institute of Ecosystem Studies in New York have embarked on a multi-year study of animal populations in a North San Francisco Bay forest infected with Sudden Oak Death.
read more in the San Jose Mercury-News
Monday, December 20, 2010
Monday, December 13, 2010
Oregon oak disease fight faces federal aid loss
BROOKINGS, Ore. (AP) — In 2001, U.S. Forest Service plant pathologist Ellen Goheen took to the air to see if sudden oak death was in Oregon.
The disease, which in two years can kill an otherwise healthy oak tree, earlier that year was identified as the causal agent killing huge swaths of oak trees in northern California.
The leading edge of the infestation was more than 100 miles from the Oregon-California border, but Goheen thought it possible that sudden oak death had entered Curry County.
Moments after starting her aerial survey, Goheen's suspicions were realized.
"The 'oh, shoot' factor was pretty high," she said.
Her discovery set off what has become a decade-long, $10 million battle with the fungal disease that threatens much of the West's timber and nursery industries.
http://www.necn.com/12/07/10/Oregon-oak-disease-fight-faces-federal-a/landing_health.html?&blockID=3&apID=5150b7d10ce24702947c0dc2d42fdbb2
The disease, which in two years can kill an otherwise healthy oak tree, earlier that year was identified as the causal agent killing huge swaths of oak trees in northern California.
The leading edge of the infestation was more than 100 miles from the Oregon-California border, but Goheen thought it possible that sudden oak death had entered Curry County.
Moments after starting her aerial survey, Goheen's suspicions were realized.
"The 'oh, shoot' factor was pretty high," she said.
Her discovery set off what has become a decade-long, $10 million battle with the fungal disease that threatens much of the West's timber and nursery industries.
http://www.necn.com/12/07/10/Oregon-oak-disease-fight-faces-federal-a/landing_health.html?&blockID=3&apID=5150b7d10ce24702947c0dc2d42fdbb2
More global trade means more forest pests
Along with U.S. manufacturing jobs, you can count another victim of global trade: American trees.
The most destructive forest pests from abroad are arriving at an accelerated pace, according to a new study. Between 1990 and 2006, new ones were discovered in the U.S. at an average rate of 1.2 per year, or nearly three times the detection rate during the previous 130 years.
The jump coincides with a rise in imports, leading the authors of a paper published in the December issue of BioScience to conclude that current rules and inspections to keep forest pests out of the country aren't that effective.
http://latimesblogs.latimes.com/greenspace/2010/12/foreign-forest-pests-on-the-rise-.html
The most destructive forest pests from abroad are arriving at an accelerated pace, according to a new study. Between 1990 and 2006, new ones were discovered in the U.S. at an average rate of 1.2 per year, or nearly three times the detection rate during the previous 130 years.
The jump coincides with a rise in imports, leading the authors of a paper published in the December issue of BioScience to conclude that current rules and inspections to keep forest pests out of the country aren't that effective.
http://latimesblogs.latimes.com/greenspace/2010/12/foreign-forest-pests-on-the-rise-.html
Public Concern About Invasive Tree Killing Insects and Diseases Remains Strong
Poll results indicate most Americans are concerned about non-native forest pests and they support measures to stop their spread
ARLINGTON, Va., Dec. 8, 2010 /PRNewswire-USNewswire/ -- Most Americans live near trees, and consider them very important to their quality of life. Recent polling by The Nature Conservancy shows that the American public is well aware of invasive forest pests that kill trees, and are willing to take steps to protect trees from this threat. According to the poll, conducted in September, knowledge of the spread of forest pests such as the Asian longhorned beetle and emerald ash borer, and of diseases like sudden oak death and thousand cankers disease, has increased by 13 percent, from 41 percent in 2005 to 54 percent in 2010. When asked about the issue of forest pests in the most general terms, 93 percent of poll respondents expressed concern. This high level of concern has not changed since 2005, despite the changing economic situation.
http://www.prnewswire.com/news-releases/public-concern-about-invasive-tree-killing-insects-and-diseases-remains-strong-111535019.html
ARLINGTON, Va., Dec. 8, 2010 /PRNewswire-USNewswire/ -- Most Americans live near trees, and consider them very important to their quality of life. Recent polling by The Nature Conservancy shows that the American public is well aware of invasive forest pests that kill trees, and are willing to take steps to protect trees from this threat. According to the poll, conducted in September, knowledge of the spread of forest pests such as the Asian longhorned beetle and emerald ash borer, and of diseases like sudden oak death and thousand cankers disease, has increased by 13 percent, from 41 percent in 2005 to 54 percent in 2010. When asked about the issue of forest pests in the most general terms, 93 percent of poll respondents expressed concern. This high level of concern has not changed since 2005, despite the changing economic situation.
http://www.prnewswire.com/news-releases/public-concern-about-invasive-tree-killing-insects-and-diseases-remains-strong-111535019.html
Massive gene loss linked to pathogen's stealthy plant-dependent lifestyle
An international team of scientists, which includes researchers from Virginia Tech, has cracked the genetic code of a plant pathogen that causes downy mildew disease. Downy mildews are a widespread class of destructive diseases that cause major losses to crops as diverse as maize, grapes, and lettuce. The paper describing the genome sequence of the downy mildew pathogen Hyaloperonospora arabidopsidis, which attacks the widely studied model plant Arabidopsis thaliana, is the cover story of this week's edition of the journal Science.
In the paper, the sequence of H. arabidopsidis is compared with other fully sequenced genomes of destructive plant pathogens to shed light on the differences in the ways microbes interact with their host and how those differences evolve. The payoff could be new ways to investigate how these pathogens wreak havoc and, in the long-term, finding how to prevent billions of dollars of losses for farmers growing crops across the globe.
http://www.eurekalert.org/pub_releases/2010-12/vt-mgl120610.php
In the paper, the sequence of H. arabidopsidis is compared with other fully sequenced genomes of destructive plant pathogens to shed light on the differences in the ways microbes interact with their host and how those differences evolve. The payoff could be new ways to investigate how these pathogens wreak havoc and, in the long-term, finding how to prevent billions of dollars of losses for farmers growing crops across the globe.
http://www.eurekalert.org/pub_releases/2010-12/vt-mgl120610.php
Tuesday, December 7, 2010
Characterizing Douglas-fir Tissue Colonization by the 'Sudden Oak Death' Pathogen, Phytophthora ramorum.
Characterizing Douglas-fir Tissue Colonization by the 'Sudden Oak Death' Pathogen, Phytophthora ramorum.
By Kathleen McKeever, M.S. and Dr. Gary Chastagner; Department of Plant Pathology, Washington State University Puyallup Research and Extension Center.
In 2001, Koch's Postulates confirmed Douglas-fir as a host for P. ramorum. Naturally-infected saplings have been observed in California forests, and studies on artificially inoculated Douglas-fir stems and shoots have established susceptibility parameters. Although naturally occurring stem infections in the U.S. have been limited to smaller diameter seedlings and saplings, P. ramorum stem cankers were recently observed on 8-year-old plantation grown Douglas-fir in Great Britain in 2009. All previous research has served to substantiate the importance of performing studies to characterize the behavior of P. ramorum in Douglas-fir and assess the potential risk that this pathogen poses to Douglas-fir ecosystems.
Artificial inoculation experiments were carried out to provide a thorough analysis of the colonization of Douglas-fir by P. ramorum. Goals of this research included determining which tissues are colonized by the pathogen, whether woody tissues are able to support sporulation, the likelihood of stem infections occurring on Douglas-fir with intact bark, and the viability of the pathogen in foliage. Methods employed included isolation, ELISA, and histological examination of stem tissues; qPCR and isolation to determine colonization efficacy and viability of the pathogen in needle tissues; and baiting studies to determine the ability of Douglas-fir bark to inhibit colonization of Rhododendron leaves by the pathogen.
ELISA results showed that proteins of the pathogen were detectable in the phloem, cambium, and superficial xylem, with infrequent detection in asymptomatic tissues. The pathogen was able to be isolated from all symptomatic woody tissues tested, but not from non-discolored tissues. ELISA and isolation techniques produced results that were highly positively correlated (r2=0.62, p=0.78), and histological observations paralleled information derived from these techniques. Douglas-fir bark reduced infection on Rhododendron leaf baits by up to 83 percent in the presence of inoculum. Results from foliage inoculations indicated that pathogen DNA is detectable using qPCR methods, but there was an inability to isolate the pathogen from needle tissue. Evidence of spore formation in woody stem tissues has not been observed.
It was concluded that the pathogen may be able to infect into the shallow xylem tissues of Douglas-fir in the presence of wounding, but there was no evidence of sporulation in tissues. The inability to isolate the pathogen from non-discolored tissues suggests that the proteins detected by ELISA outside of the lesion may be elicitins that are secreted in advance of hyphal colonization. The inability to isolate the pathogen from colonized needles may indicate the presence of chemical inhibitors that render the pathogen non-viable subsequent to initial infection. Finally, the ability of Douglas-fir bark to suppress infection of Rhododendron leaf baits suggests that the bark is inhibitory to P. ramorum and that infection of woody stem tissues through intact bark may be limited. Further research is required to identify the nature of this inhibition.
Characterization of P. ramorum colonization of Douglas-fir tissues is relevant to our current understanding of the behavior of the pathogen in different hosts and may enhance our ability to assess risk and create adequate regulations to thwart the spread of this exotic pathogen.
from the December COMTF newsletter
By Kathleen McKeever, M.S. and Dr. Gary Chastagner; Department of Plant Pathology, Washington State University Puyallup Research and Extension Center.
In 2001, Koch's Postulates confirmed Douglas-fir as a host for P. ramorum. Naturally-infected saplings have been observed in California forests, and studies on artificially inoculated Douglas-fir stems and shoots have established susceptibility parameters. Although naturally occurring stem infections in the U.S. have been limited to smaller diameter seedlings and saplings, P. ramorum stem cankers were recently observed on 8-year-old plantation grown Douglas-fir in Great Britain in 2009. All previous research has served to substantiate the importance of performing studies to characterize the behavior of P. ramorum in Douglas-fir and assess the potential risk that this pathogen poses to Douglas-fir ecosystems.
Artificial inoculation experiments were carried out to provide a thorough analysis of the colonization of Douglas-fir by P. ramorum. Goals of this research included determining which tissues are colonized by the pathogen, whether woody tissues are able to support sporulation, the likelihood of stem infections occurring on Douglas-fir with intact bark, and the viability of the pathogen in foliage. Methods employed included isolation, ELISA, and histological examination of stem tissues; qPCR and isolation to determine colonization efficacy and viability of the pathogen in needle tissues; and baiting studies to determine the ability of Douglas-fir bark to inhibit colonization of Rhododendron leaves by the pathogen.
ELISA results showed that proteins of the pathogen were detectable in the phloem, cambium, and superficial xylem, with infrequent detection in asymptomatic tissues. The pathogen was able to be isolated from all symptomatic woody tissues tested, but not from non-discolored tissues. ELISA and isolation techniques produced results that were highly positively correlated (r2=0.62, p=0.78), and histological observations paralleled information derived from these techniques. Douglas-fir bark reduced infection on Rhododendron leaf baits by up to 83 percent in the presence of inoculum. Results from foliage inoculations indicated that pathogen DNA is detectable using qPCR methods, but there was an inability to isolate the pathogen from needle tissue. Evidence of spore formation in woody stem tissues has not been observed.
It was concluded that the pathogen may be able to infect into the shallow xylem tissues of Douglas-fir in the presence of wounding, but there was no evidence of sporulation in tissues. The inability to isolate the pathogen from non-discolored tissues suggests that the proteins detected by ELISA outside of the lesion may be elicitins that are secreted in advance of hyphal colonization. The inability to isolate the pathogen from colonized needles may indicate the presence of chemical inhibitors that render the pathogen non-viable subsequent to initial infection. Finally, the ability of Douglas-fir bark to suppress infection of Rhododendron leaf baits suggests that the bark is inhibitory to P. ramorum and that infection of woody stem tissues through intact bark may be limited. Further research is required to identify the nature of this inhibition.
Characterization of P. ramorum colonization of Douglas-fir tissues is relevant to our current understanding of the behavior of the pathogen in different hosts and may enhance our ability to assess risk and create adequate regulations to thwart the spread of this exotic pathogen.
from the December COMTF newsletter
Soil positive for P. ramorum in WA
A Gig Harbor, Pierce County, WA landscape site adjacent to a previously positive repeat nursery has been found to have P. ramorum-positive soil. The confirmed site is along a drainage that had been found positive with infected salal plants in the summer of 2009. Soil sampling has been ongoing since the initial confirmation; however, this is the first time a positive sample has been recovered. The nursery associated with the site closed in August 2010, yet the retention ponds and outlet for the ponds continue to be positive for the pathogen. The nursery site is currently up for sale. The county has volunteered to remove the remaining host plants and material on the drainage banks where the previous salal find was confirmed in an effort to eliminate the pathogen's ability to become established. Survey work will also continue in the area. For more information, contact Michael Schell at michael.r.schell@aphis.usda.gov.
From the December COMTF newsletter
From the December COMTF newsletter
New research on mating hormone for control of P. infestans
ScienceDaily (Nov. 17, 2010) — Scientists are reporting a key advance toward development of a way to combat the terrible plant diseases that caused the Irish potato famine and still inflict billions of dollars of damage to crops each year around the world. Their study appears in ACS' journal Organic Letters.
Read the whole article at Science Daily
Read the whole article at Science Daily
Battle against Sudden Oak Disease tough, but essential
As you may have read in the Curry Coastal Pilot, the Oregon Board of Forestry recently met in Brookings and toured areas affected by Sudden Oak Death (SOD), the tree disease caused by the non-native pathogen Phytophthora ramorum. SOD is a relatively new disease to Oregon. Since its discovery in the Brookings area in 2001, forest managers in the public and private sectors have been working together to locate infected trees, eradicate the pathogen from infested sites, and slow the spread of the disease.
Cutting and burning infected and nearby trees may seem crude but it is the best disease management tool available to us. There is nothing we can spray to kill the pathogen or prevent trees from becoming infected. Cutting and burning infected trees, many of them still green, destroys the pathogen and reduces the potential for spread of air-borne spores. Unfortunately, it doesn’t always work as planned. Inconsistent funding often has delayed treatment and allowed the disease to spread before we can destroy it.
http://www.currypilot.com/20101124116570/Opinion/Public-Forums/Battle-against-Sudden-Oak-Disease-tough-but-essential
Cutting and burning infected and nearby trees may seem crude but it is the best disease management tool available to us. There is nothing we can spray to kill the pathogen or prevent trees from becoming infected. Cutting and burning infected trees, many of them still green, destroys the pathogen and reduces the potential for spread of air-borne spores. Unfortunately, it doesn’t always work as planned. Inconsistent funding often has delayed treatment and allowed the disease to spread before we can destroy it.
http://www.currypilot.com/20101124116570/Opinion/Public-Forums/Battle-against-Sudden-Oak-Disease-tough-but-essential
Plant disease threatens traditions of California tribes
From 2009:
Mary Larson Bishop gazes at the folds and peaks of the Santa Lucia Range with longing. "I used to go deep into the woods looking for herbs," says the Salinan tribal elder, who is known for her knowledge of medicinal plants such as yerba santa, traditionally used to heal skin inflammation. Now, she no longer roams the Central California coastal hills. "I'm afraid of bringing anything out of the woods that might spread to other trees," says Bishop. "I don't want to track that crud out of the hills."
The "crud" is Phytophthora ramorum, a minuscule waterborne mold that weakens and kills many species of native trees and plants. The pathogen, which causes both Sudden Oak Death and Ramorum blight, was first discovered in the mid-1990s. Since then, it has spread to 14 California counties along the Pacific Coast, and even to Washington and Oregon. It travels by clinging to boots, hands, pant legs and tires.
http://www.hcn.org/issues/41.12/cultural-blight
Mary Larson Bishop gazes at the folds and peaks of the Santa Lucia Range with longing. "I used to go deep into the woods looking for herbs," says the Salinan tribal elder, who is known for her knowledge of medicinal plants such as yerba santa, traditionally used to heal skin inflammation. Now, she no longer roams the Central California coastal hills. "I'm afraid of bringing anything out of the woods that might spread to other trees," says Bishop. "I don't want to track that crud out of the hills."
The "crud" is Phytophthora ramorum, a minuscule waterborne mold that weakens and kills many species of native trees and plants. The pathogen, which causes both Sudden Oak Death and Ramorum blight, was first discovered in the mid-1990s. Since then, it has spread to 14 California counties along the Pacific Coast, and even to Washington and Oregon. It travels by clinging to boots, hands, pant legs and tires.
http://www.hcn.org/issues/41.12/cultural-blight
Deadly P lateralis tree disease found at Loch Lomond
A deadly tree disease never seen in Britain before has been detected on the shores of Loch Lomond.
P. lateralis is a close relative of P. ramorum and is a root pathogen on Port Orford Cedar.
Read the rest of the article here:
http://www.bbc.co.uk/news/uk-scotland-11879891
P. lateralis is a close relative of P. ramorum and is a root pathogen on Port Orford Cedar.
Read the rest of the article here:
http://www.bbc.co.uk/news/uk-scotland-11879891
OAN makes case to Oregon congressional delegation for action during lame duck session
OAN supports funding continued efforts to contain and control Phytophthora ramorum, the pathogen that causes sudden oak death. Additionally, our delegation must pressure USDA not to implement its damaging and discriminatory prenofitication rule, requiring all nurseries to notify receiving states of host material shipped from Oregon.
http://oangovernmentrelations.blogspot.com/2010/12/oan-makes-case-to-oregon-congressional.html
http://oangovernmentrelations.blogspot.com/2010/12/oan-makes-case-to-oregon-congressional.html
Monday, November 8, 2010
Phytophthora ramorum's threat to the East Coast
Phytophthora ramorum's threat to the East Coast was discussed at the Address P. ramorum Initiative breakout session held at Brandeis University, October 6, 2010, as part of the sixth meeting of the Continental Dialogue of Non-native Insects and Diseases. A poster and handout summarized what is known: The Sudden Oak Death pathogen has been detected in eight rivers in Mississippi, Alabama, Georgia, Florida, and North Carolina. These contaminated waterways are near P. ramorum-positive nurseries. Several of the streams are in areas identified by the USDA Forest Service as "high risk" for infestation due to the presence of susceptible vegetation and suitable climate. The group discussed preliminary plans for 2011, which may include a meeting for interested parties to learn more about the Forest Service "Sudden Oak Death Framework" and recommendations to the USDA Animal and Plant Health Inspection Service from interagency work groups on current P. ramorum regulations. The Address P. ramorum Initiative's goal is to prevent the spread of P. ramorum and work in a collaborative, proactive, cooperative manner. For more information, contact the Initiative co-leads: Ken Rauscher, Jerry Lee, or Susan Frankel.
Monday, October 18, 2010
Buy It Where You Burn It campaign covers OR, WA & ID
Moving firewood also moves invasive species, including P. ramorum
Buying local firewood protects Oregon forestry and ag
– Imported firewood is a major pathway for invasive species
By Oregon Department of Agriculture
Buy local has a whole new meaning when it comes to protecting Oregon from invasive species this fall and winter. Consumers are urged not to purchase firewood from out-of-state and all the insects and diseases it might carry. Instead, buying local firewood can help keep invasive species from gaining a foothold in the Oregon environment.
“Firewood is a major pathway for moving invasive species, and that’s not a good thing,” says Dan Hilburn, administrator of the Oregon Department of Agriculture’s Plant Division and member of the Oregon Invasive Species Council (OISC). “The take home message to Oregonians is to buy their firewood locally and burn it locally.”
Whether it is used at a campground or at home, people are transporting firewood great distances these days, taking with them any bugs or diseases that might not be native to that area.
http://naturalresourcereport.com/2010/10/buy-it-where-you-burn-it-campaign-covers-or-wa-id/
Buying local firewood protects Oregon forestry and ag
– Imported firewood is a major pathway for invasive species
By Oregon Department of Agriculture
Buy local has a whole new meaning when it comes to protecting Oregon from invasive species this fall and winter. Consumers are urged not to purchase firewood from out-of-state and all the insects and diseases it might carry. Instead, buying local firewood can help keep invasive species from gaining a foothold in the Oregon environment.
“Firewood is a major pathway for moving invasive species, and that’s not a good thing,” says Dan Hilburn, administrator of the Oregon Department of Agriculture’s Plant Division and member of the Oregon Invasive Species Council (OISC). “The take home message to Oregonians is to buy their firewood locally and burn it locally.”
Whether it is used at a campground or at home, people are transporting firewood great distances these days, taking with them any bugs or diseases that might not be native to that area.
http://naturalresourcereport.com/2010/10/buy-it-where-you-burn-it-campaign-covers-or-wa-id/
Monday, October 11, 2010
New nursery research projects at NORS-DUC
Pending California Department of Pesticide Regulation approval, the following five projects will soon be underway at the National Ornamentals Research Site at Dominican University of California (NORS-DUC). All projects have been funded through the fiscal year federal Farm Bill. For more information on the projects or the NORS-DUC program, contact Sibdas Ghosh at sibdas.ghosh@dominican.edu.
Bostock, R.M. and Roubtsova, T. Episodic abiotic stress and ramorum blight in nursery ornamentals: impacts on symptom expression and chemical management of Phytophthora ramorum in Rhododendron.
Chastagner, G. and Elliott, M. The risk of asymptomatic Phytophthora ramorum infection on fungicide treated rhododendrons.
Jeffers, S.; Meadows, I.; Hwang, J.-S. Studies on Soil Mitigation of Phytophthora ramorum.
Tjosvold, S.; Chastagner, G.; and Elliott, M. Effect of fungicides and biocontrol agents on inoculum production and persistence of Phytophthora ramorum on nursery hosts.
Widmer, T. and Shishkoff, N. Use of Trichoderma spp. to remediate Phytophthora ramorum-infested soil.
Bostock, R.M. and Roubtsova, T. Episodic abiotic stress and ramorum blight in nursery ornamentals: impacts on symptom expression and chemical management of Phytophthora ramorum in Rhododendron.
Chastagner, G. and Elliott, M. The risk of asymptomatic Phytophthora ramorum infection on fungicide treated rhododendrons.
Jeffers, S.; Meadows, I.; Hwang, J.-S. Studies on Soil Mitigation of Phytophthora ramorum.
Tjosvold, S.; Chastagner, G.; and Elliott, M. Effect of fungicides and biocontrol agents on inoculum production and persistence of Phytophthora ramorum on nursery hosts.
Widmer, T. and Shishkoff, N. Use of Trichoderma spp. to remediate Phytophthora ramorum-infested soil.
Helping to map the SOD outbreak in California
Sudden oak death: Plotting trail, testing leaves
A map plotting the path of destruction that the tree-strangling pathogen known as sudden oak death is taking through the Bay Area shows new infestations in and around neighborhoods throughout the region.
The effort to track the wily killer's movements is the result of a major effort to involve citizens in the battle against the mysterious pathogen, which has killed tens of thousands of oak trees from Big Sur to southern Oregon.
Read more: San Francisco Chronicle, Oct. 4 2010
A map plotting the path of destruction that the tree-strangling pathogen known as sudden oak death is taking through the Bay Area shows new infestations in and around neighborhoods throughout the region.
The effort to track the wily killer's movements is the result of a major effort to involve citizens in the battle against the mysterious pathogen, which has killed tens of thousands of oak trees from Big Sur to southern Oregon.
Read more: San Francisco Chronicle, Oct. 4 2010
Monday, August 30, 2010
Citizen Science
Citizen science has been around for centuries, with lay people collecting data and making observations for scientists in a variety of fields. And, citizen scientists are contributing to discoveries as much in the 21st century as ever before.
Read more here:
NSF Science Nation -The online magazine that's all about science for the people
and if you're interested in joining WSU's stream monitoring for Phytophthora program, let Marianne know.
Read more here:
NSF Science Nation -The online magazine that's all about science for the people
and if you're interested in joining WSU's stream monitoring for Phytophthora program, let Marianne know.
Wednesday, August 25, 2010
P. ramorum spread to Northern Ireland
Tree killing disease spreads to NI
A private woodland and two government-owned forests in Northern Ireland have been devastated by an outbreak of a killer disease.
It has become known as Sudden Oak Death, but it is really a fungal-like infection that kills Japanese larch trees.
Read the rest of the article here:
BBC News
A private woodland and two government-owned forests in Northern Ireland have been devastated by an outbreak of a killer disease.
It has become known as Sudden Oak Death, but it is really a fungal-like infection that kills Japanese larch trees.
Read the rest of the article here:
BBC News
Research on SOD at Fort Detrick
Fort Detrick USDA unit a quiet but important part of global food security
On opposite ends of Fort Detrick, overshadowed by the mammoth infectious disease laboratories that sit in between, are two sets of greenhouses belonging to the U.S. Department of Agriculture.
The diseases studied inside aren't as infamous as the anthrax and Ebola tested elsewhere at Fort Detrick, but the USDA research in the greenhouses saves plants vital to the farming, lumber and tourism industries.
Read the rest of the article here:
The Frederick News-Post Online
On opposite ends of Fort Detrick, overshadowed by the mammoth infectious disease laboratories that sit in between, are two sets of greenhouses belonging to the U.S. Department of Agriculture.
The diseases studied inside aren't as infamous as the anthrax and Ebola tested elsewhere at Fort Detrick, but the USDA research in the greenhouses saves plants vital to the farming, lumber and tourism industries.
Read the rest of the article here:
The Frederick News-Post Online
Monday, August 16, 2010
"Sudden Larch Death" in the UK
Plant pathology: Sudden larch death
Clive Brasier & Joan Webber
Nature 466:824–825
Date published:(12 August 2010)
doi:10.1038/466824a
An aggressive and unpredictable fungal pathogen is devastating larch plantations in Britain. Its remarkably broad host range, and the possibility of further geographical spread, give heightened cause for concern.
read the whole article here
Clive Brasier & Joan Webber
Nature 466:824–825
Date published:(12 August 2010)
doi:10.1038/466824a
An aggressive and unpredictable fungal pathogen is devastating larch plantations in Britain. Its remarkably broad host range, and the possibility of further geographical spread, give heightened cause for concern.
read the whole article here
Monday, August 9, 2010
Adorn fungicide registered for use in California
Valent’s new chemistry provides control of key diseases, resistance management.
WALNUT CREEK, Calif. – Valent Professional Products announced that Adorn fungicide has been registered for use on ornamentals in California. Adorn is a new chemistry that controls downy mildew, Phytophthora and Pythium in greenhouse, nursery and outdoor landscape settings.
Available for use as a spray or drench, Adorn is effective against a number of diseases affecting California ornamentals, including sudden oak death (SOD) or Phytophthora ramorum. With a new mode of action, Adorn is also an excellent addition to fungicide rotations and plays a key role in resistance management programs when used as part of a tank mix.
Adorn has low-use rates of 1 to 2 ounces per 100 gallons as a drench and 2 to 4 ounces per 100 gallons as a spray. With its translaminar activity, Adorn provides enhanced plant coverage to help ensure growers and LCOs get more from their fungicide.
Lawn & Landscape
Download the label for Adorn Fungicide
WALNUT CREEK, Calif. – Valent Professional Products announced that Adorn fungicide has been registered for use on ornamentals in California. Adorn is a new chemistry that controls downy mildew, Phytophthora and Pythium in greenhouse, nursery and outdoor landscape settings.
Available for use as a spray or drench, Adorn is effective against a number of diseases affecting California ornamentals, including sudden oak death (SOD) or Phytophthora ramorum. With a new mode of action, Adorn is also an excellent addition to fungicide rotations and plays a key role in resistance management programs when used as part of a tank mix.
Adorn has low-use rates of 1 to 2 ounces per 100 gallons as a drench and 2 to 4 ounces per 100 gallons as a spray. With its translaminar activity, Adorn provides enhanced plant coverage to help ensure growers and LCOs get more from their fungicide.
Lawn & Landscape
Download the label for Adorn Fungicide
Swansea Bay rally halted after tree disease
The Swansea Bay Rally, postponed last month due to a tree disease, has been cancelled for 2010, say organisers.
The event, due to start and finish outside Swansea Museum on 17 July, was called off at short notice.
The route, near Resolven and Rhondda, went through areas that have been hit by the Phytophthora ramorum infection, also known as as "sudden oak death".
Rally organisers said the event could not be re-scheduled to take other qualifying rounds into account.
The rally, which has been running for almost 40 years, is part of the MSA National Gravel Rally Championship.
Around 80 semi-professional and club drivers were due to take part.
read the whole article on BBC News
The event, due to start and finish outside Swansea Museum on 17 July, was called off at short notice.
The route, near Resolven and Rhondda, went through areas that have been hit by the Phytophthora ramorum infection, also known as as "sudden oak death".
Rally organisers said the event could not be re-scheduled to take other qualifying rounds into account.
The rally, which has been running for almost 40 years, is part of the MSA National Gravel Rally Championship.
Around 80 semi-professional and club drivers were due to take part.
read the whole article on BBC News
Tuesday, August 3, 2010
Research projects funded by USFS
Including some at WSU:
The USDA Forest Service, Pacific Southwest Research Station Sudden Oak Death/P. ramorum research program list of 2010 funded projects is now available at http://www.fs.fed.us/psw/programs/sod/funding/FY2010PSWSODFunding.pdf.
Thirteen new projects as well as 14 continuing projects were funded, for a total of $1,401,441. For more information, contact Susan Frankel at sfrankel@fs.fed.us.
The USDA Forest Service, Pacific Southwest Research Station Sudden Oak Death/P. ramorum research program list of 2010 funded projects is now available at http://www.fs.fed.us/psw/programs/sod/funding/FY2010PSWSODFunding.pdf.
Thirteen new projects as well as 14 continuing projects were funded, for a total of $1,401,441. For more information, contact Susan Frankel at sfrankel@fs.fed.us.
Nursery update for WA and OR
A King County, Washington retail nursery was found to have six
P. ramorum-positive rhododendrons in July. This nursery was also found positive for the pathogen in 2004, 2005, and 2006. CNP is underway. To date in 2010, the Washington State Department of Agriculture has processed more than 13,000 samples and detected P. ramorum at eight nurseries. For more information, contact Brad White at bwhite@agr.wa.gov.
A Washington County, Oregon retail nursery was found with two
P. ramorum-positive Rhododendron plants in mid-July. The nursery requested a survey after identifying a potential out-of-state customer. Prior to the confirmation, the nursery had not shipped interstate. This is the first time P. ramorum has been detected in this nursery. The USDA Retail CNP has been enacted.
As of 7/21, the Oregon Department of Agriculture has completed testing for the 2010 P. ramorum Federal Order Survey on 15,670 samples collected from 392 nursery grower locations. So far, P. ramorum has been detected in seven Oregon nurseries, with three nurseries having completed the CNP. For more information, contact Nancy Osterbauer at nosterba@oda.state.or.us.
From the August COMTF newsletter
P. ramorum-positive rhododendrons in July. This nursery was also found positive for the pathogen in 2004, 2005, and 2006. CNP is underway. To date in 2010, the Washington State Department of Agriculture has processed more than 13,000 samples and detected P. ramorum at eight nurseries. For more information, contact Brad White at bwhite@agr.wa.gov.
A Washington County, Oregon retail nursery was found with two
P. ramorum-positive Rhododendron plants in mid-July. The nursery requested a survey after identifying a potential out-of-state customer. Prior to the confirmation, the nursery had not shipped interstate. This is the first time P. ramorum has been detected in this nursery. The USDA Retail CNP has been enacted.
As of 7/21, the Oregon Department of Agriculture has completed testing for the 2010 P. ramorum Federal Order Survey on 15,670 samples collected from 392 nursery grower locations. So far, P. ramorum has been detected in seven Oregon nurseries, with three nurseries having completed the CNP. For more information, contact Nancy Osterbauer at nosterba@oda.state.or.us.
From the August COMTF newsletter
SOD situation in Britain
Britain's Forestry Commission is continuing to try to minimize the spread of P. ramorum by felling tens of thousands of Japanese larch (Larix kaempferi), first found to be a sporulating host in southwest England in fall 2009. Since then, thousands of trees have died. Follow-up aerial surveys in southwest England and Wales, and up into western Scotland, have identified 203 suspicious sites in a mix of privately owned and Forestry Commission public woodlands in England and Wales. Of these, 42 sites in southwest England and eight in Wales have confirmed infestations. More than 30 hectares of trees were felled last winter, with an additional 250 hectares planned for removal this summer and fall. Felling is continuing in the southwest England counties of Devon and Cornwall, including Plym Woods, a popular forest for public recreation near the city of Plymouth, and is getting under way in Wales. The Forestry Commission hopes that by taking decisive action in southwest England and south Wales it can prevent the pathogen from spreading further into Britain.
Affected forests are remaining open to visitors, except for areas where felling is taking place, due to safety reasons. Visitors are being asked to stay on stone paths, keep dogs on short leads, and clean shoes and bikes before leaving infested areas. Private landowners are also being asked to regularly inspect woodlands where larch is present and to report any suspected P. ramorum outbreaks to the Forestry Commission. For more information, go to http://www.forestry.gov.uk/pramorum.
From the August COMTF newsletter
Affected forests are remaining open to visitors, except for areas where felling is taking place, due to safety reasons. Visitors are being asked to stay on stone paths, keep dogs on short leads, and clean shoes and bikes before leaving infested areas. Private landowners are also being asked to regularly inspect woodlands where larch is present and to report any suspected P. ramorum outbreaks to the Forestry Commission. For more information, go to http://www.forestry.gov.uk/pramorum.
From the August COMTF newsletter
Monday, July 26, 2010
Key Finding: Many Pathogenic Fungi Use the Same Entrance to Invade Host Cells
Some crop--and even human--diseases might be stopped dead in their tracks if researchers can harness a new discovery about how pathogens first infect their hosts.
Like a burglar with a universal lock pick, many deadly pathogens use the same protein to gain access to the cells of a potential host, researchers have discovered. The new findings could have implications for blocking infections by agents ranging from wheat rust to malaria.
Pathogenic fungi, such as flax rust and soybean rust, and similar pathogens known as oomycetes, such as the organism behind the Irish potato famine and sudden oak death, make similar proteins to disarm their hosts' defenses. But to work, these effector proteins need to first make their way inside of a cell. And until now, scientists did not know, in the first place, how these compounds were able to break in.
A new study, published online July 22 in Cell describes how these blights do it.
Read the full article in Scientific American
Like a burglar with a universal lock pick, many deadly pathogens use the same protein to gain access to the cells of a potential host, researchers have discovered. The new findings could have implications for blocking infections by agents ranging from wheat rust to malaria.
Pathogenic fungi, such as flax rust and soybean rust, and similar pathogens known as oomycetes, such as the organism behind the Irish potato famine and sudden oak death, make similar proteins to disarm their hosts' defenses. But to work, these effector proteins need to first make their way inside of a cell. And until now, scientists did not know, in the first place, how these compounds were able to break in.
A new study, published online July 22 in Cell describes how these blights do it.
Read the full article in Scientific American
Monday, July 12, 2010
Schmidt, D. and Garbelotto, M. 2010. Efficacy of phosphonate treatments against Sudden Oak Death in tanoaks. Phytopathology 100:S115.
Pytophthora ramorum, the causal agent of Sudden Oak Death (SOD), has killed hundreds of thousands of trees in California and Oregon. Tanoaks (Lithocarpus densiflorus) are both stem and foliar hosts and, as such, die from SOD and help spread the disease. Phosphonate treatments are routinely used in agricultural and orchard crops affected by Phytophthora diseases. We have developed a detached-leaf bioassay for studying the effectiveness of phosphonate treatments for SOD in tanoaks. The assay involves infecting the petioles of tanoak leaves with agar plugs of P. ramorum in culture. SOD infection is analyzed by examining the spread of P. ramorum down the midrib of the leaf. This assay has shown that tanoaks in wildland settings, treated with phosphonates, are resistant to SOD infection. In addition, we are maintaining long-term studies of tanoaks treated with phosphonates in SOD infected forest areas. Paired 20mx20m treatment and control plots were established near existing SOD infections. The trees were evaluated for disease symptoms and general health prior to the initial treatment and each subsequent year. The results show that phosphonate treatments are effective at slowing and preventing the spread of the disease in the treated areas. Treatments at the leading edge of SOD infected areas were less effective, confirming that phosphonate treatments are significantly more effective as preventative rather than curative treatments.
Phytophthora species in streams
Hwang, J.; Jeffers, S.N.; and Oak, S.W. 2010. Aquatic habitats—A reservoir for population diversity in the genus Phytophthora. Phytopathology 100:S150.
Occurrences of oak decline and sudden oak death in forests of Europe and the west coast of the U.S.A., respectively, have focused attention on the species of Phytophthora present in natural ecosystems. We have been investigating the diversity of species of Phytophthora present in forest streams in the eastern U.S.A. Phytophthora spp. are well adapted to aquatic environments and can be recovered from stream water by baiting and filtration. Extensive surveys in multiple states revealed that a diversity of species occurs naturally in forest streams. In one study, five forest streams in western North Carolina were monitored monthly for a year. Seven species—P. cambivora, P. cinnamomi, P. citricola, P. citrophthora, P. gonapodyides, P. heveae, and P. pseudosyringae—and seven morphologically and genetically distinct groups of isolates were detected. Samples of stream-side soils and plants with symptoms also were collected, but only three species were detected: P. cinnamomi and P. heveae in soils and P. citricola and P. heveae on plants. Species of Phytophthora consistently were detected in streams during winter months when air temperatures were near or below freezing, which are not conducive to lesion development and sporulation. These results suggest that the native population of Phytophthora spp. in stream water is different from those in terrestrial habitats. The species of Phytophthora present in streams may occupy a unique niche—i.e., they appear to be aquatic inhabitants and not transient visitors.
Genetic diversity of P. ramorum population in Canada
Goss, E.M.; Larsen, M.; Vercauteren, A.; Werres, S.; Heungens, K.; and Grunwald, N.J. 2010. Genotypic diversity of Phytophthora ramorum in Canada. Phytopathology 100:S42.
Characterization of the genetic structure and diversity of the sudden oak death pathogen, Phythophthora ramorum, in ornamental nurseries in the United States has shown that all three known clonal lineages of the pathogen are present. The most common clonal lineage in U.S. nurseries has been the NA1 clonal lineage, which has the wider distribution in the United States as a result of interstate shipments of infected nursery stock. British Columbia (BC), Canada is also known to have nursery infestations of P. ramorum, and shipments of infected plants between the United States and BC have occurred. We investigated the genotypic diversity of P. ramorum in BC nurseries and compared this population to U.S. and European nursery populations. All three of the P. ramorum clonal lineages were found among Canadian nursery isolates, but the most common was the NA2 lineage. The NA1 clonal lineage was found infrequently in comparison to the United States. The EU1 lineage was observed almost every year and shared multilocus genotypes with isolates from Europe and the United States. Appropriate markers for the characterization of the NA2 lineage are needed.
Stream in NC positive for P. ramorum
Water draining an infested nursery in Mecklenburg County (Charlotte), NC has been found to have Phytophthora ramorum as a result of the 2010 National P. ramorum Early Detection Survey of Forests. The rhododendron leaf baits were deployed by survey cooperators in the NC Forest Service and diagnosis made from several baiting periods via PCR by the survey's Eastern Regional Diagnostic Lab at the Pennsylvania Department of Agriculture. This brings the total number of positive waterways to 10 in six states outside areas where P. ramorum is found in California and Oregon forest areas (WA [2], AL [4], MS [1], GA [1], FL [1], and NC [1]). Cooperative streamside vegetation surveys are being planned for the fall by the USDA Forest Service, NC Forest Service, and NC Department of Agriculture and Consumer Services to determine if the pathogen has become established in terrestrial ecosystems.
from COMTF July newsletter
from COMTF July newsletter
Monday, June 28, 2010
Agency delays plan targeting sudden oak death
Nurseries say APHIS order provides more paperwork, but not more protection
By MITCH LIES
Capital Press
Federal officials provided West Coast nurseries breathing room this week when they delayed a new requirement for shipping nursery stock that can host sudden oak death.
But the delay falls short of easing industry concerns.
USDA Animal and Plant Health Inspection Service officials earlier this month told West Coast agriculture officials they planned to delay by as much as three weeks implementation of the federal order. It was initially scheduled to start June 21.
The order requires nurseries in Oregon, Washington and California to notify receiving states in writing when they ship nursery stock that can host Phytophthora ramorum, the fungus associated with sudden oak death.
Read the full article here - http://www.capitalpress.com/orewash/ml-sod-federal-order-062510
Thursday, June 17, 2010
Two nurseries positive for P. ramorum in May
Washington was found to have two P. ramorum-positive nurseries in May. (1) On 5/3 a Thurston County wholesale/production nursery was found to have P. ramorum-positive Mahonia nervosa and Viburnum tinus as a result of a nursery compliance inspection. This nursery ships interstate and was previously positive for P. ramorum in 2008. Trace-forward and -back investigations are underway. (2) A Snohomish County wholesale nursery was determined to have P. ramorum-positive Rhododendron sp. on 5/6 as a result of a nursery compliance inspection. This nursery ships interstate and was previously positive for P. ramorum in 2008. Trace-forward and -back investigations are underway.
Monday, June 14, 2010
A Tale of Three Nurseries
A heartwarming (or frightening) tale of three nurseries, reposted from the Oregon Invasive Species blog:
Once upon a time there were three nurseries. As long as people could remember, these nurseries had been growing and selling plants to satisfied customers. The nurseries were called: Clean and Green, Pretty Good Plants, and Cuttin Corners....
read the whole story here:
http://oregoninvasivespecies.blogspot.com/2010/06/tale-of-three-nurseries.html
Once upon a time there were three nurseries. As long as people could remember, these nurseries had been growing and selling plants to satisfied customers. The nurseries were called: Clean and Green, Pretty Good Plants, and Cuttin Corners....
read the whole story here:
http://oregoninvasivespecies.blogspot.com/2010/06/tale-of-three-nurseries.html
SOD found in South Wales on larch
Forestry Commission experts are working to contain the spread of Phytophthora ramorum infection to Japanese larch trees in South Wales.
Phytophthora ramorum (P. ramorum) is a fungus-like pathogen that kills many of the trees and plants that it infects. Japanese larch trees infected by P. ramorum were first found in South West England last year, the only place in the world where it has attacked large numbers of a commercially grown species of conifer tree.
This development was a step change in the pathogen’s behaviour. Since first being identified in Britain in 2002, on a viburnum plant in a garden centre, it had affected mostly shrub and ground-cover plants such as rhododendron, viburnum and bilberry. Fewer than 100 infected trees – mostly beech - had been found, and most of those were standing close to infected rhododendron bushes.
Although it has been confirmed in only one area of larch forest in Wales so far, Forestry Commission Wales expects to find more as ground inspections follow up the aerial surveys that have pinpointed suspect areas of woodland. Scientists at the Commission’s Forest Research arm believe it likely that the spores that spread the disease have been spread to the larch forests in rain, mists and air currents carried across the Bristol Channel from the South-west, where it was confirmed in Japanese larch last September.
Roddie Burgess, Head of the Forestry Commission’s Plant Health Service, said the Commission and its partners are taking the development very seriously, but hope to be able to contain it.
http://www.forestry.gov.uk/newsrele.nsf/AllByUNID/11FB60906B36B2C68025773D005CD276
Wednesday, May 5, 2010
How pathogens can survive in aquatic environments
This article may give some insights into how P. ramorum can persist in a stream environment:
Islands of Germs: Researchers Discover Pathogens Floating on Tiny Clumps of Aquatic Detritus
Researchers have found evidence that "marine snow"--aggregates of organic material floating in water bodies--may act as microscopic, island-like refuges for pathogens, or disease-causing organisms. This detritus may skew water sampling procedures and mathematical models used to predict the transmission of waterborne diseases to humans.
(follow the link above to read the whole article)
Islands of Germs: Researchers Discover Pathogens Floating on Tiny Clumps of Aquatic Detritus
Researchers have found evidence that "marine snow"--aggregates of organic material floating in water bodies--may act as microscopic, island-like refuges for pathogens, or disease-causing organisms. This detritus may skew water sampling procedures and mathematical models used to predict the transmission of waterborne diseases to humans.
(follow the link above to read the whole article)
WSU stream monitoring program
The Washington State University, Puyallup (WSU-P) SOD community-based stream monitoring program was piloted in March 2010 in Washington's Puget Sound region. In addition to increasing the number of streams monitored for P. ramorum throughout the state by the Washington State Department of Agriculture (WSDA) and Washington Department of Natural Resources (WADNR), the new program also has potential to increase community awareness about the spread of P. ramorum and other Phytophthoras in streams. WSU-P received two years worth of funding from the USDA Forest Service to manage this program, which involves Master Gardeners, high school and college students, and other volunteers. Baiting sites were chosen based on discussions with WSDA and WADNR, and also volunteer availability. In 2010 four sites are being monitored for six two-week intervals and three sites for one two-week interval. The two-week interval sites are part of class projects for UW-Tacoma and Pierce College. Some students are also doing projects in the lab related to disinfectant use and survival in saline conditions. The program will be expanded in 2011. No P. ramorum has been detected at any of the sites so far. For more information, go to http://www.puyallup.wsu.edu/ppo/sod/monitoring/stream%20monitoring.htm or contact Marianne Elliott at melliott2@wsu.edu.
From the May COMTF newsletter
From the May COMTF newsletter
WSDA survey results
The Washington State Department of Agriculture (WSDA) has surveyed 30 host and non-host nurseries to date this year for P. ramorum, all of which have been negative for the pathogen. Some shippers in the state have greatly reduced the amount of high-risk genera (Camellia, Rhododendron, Pieris, Viburnum, and Kalmia) inventory for sale in an effort to reduce the risk of a P. ramorum find. However, two nurseries continue to yield positive water samples - one in Pierce County and one in King County. These sites continue to be monitored as no infected plants have been found in association with the positive water and the inoculum source is unknown. February and April surveys of plants downstream from the Pierce County positive nursery perimeter salal find in 2009 found no positive plants, and the Rosedale Stream has been continuously baited since January 2010, with no positive water finds. WSDA also followed up on trace-forward investigations from a Pennsylvania positive nursery, of which all 160 Laurus nobilis imported plants were free of P. ramorum.
From the May COMTF newsletter
From the May COMTF newsletter
Friday, April 16, 2010
Thursday, April 15, 2010
'PC' disease devastating African palm plantations
Another destructive Phytophthora disease (P. palmivora) attacking oil palms in the tropics:
http://seattletimes.nwsource.com/html/nationworld/2011597413_palmoil14.html
http://seattletimes.nwsource.com/html/nationworld/2011597413_palmoil14.html
Thursday, April 8, 2010
Nursery news
A Clark County, WA production nursery was found to have P. ramorum infested soil on 3/10/10. A delimiting survey was conducted. This nursery was also found P. ramorum positive in 2008 and 2009.
From the April COMTF newsletter
From the April COMTF newsletter
Update on conifer hosts of P. ramorum in the UK
This is of interest to Washington because Douglas-fir and western hemlock are important forest species here:
"The 2009 UK sites where Japanese larch (Larix kaempferi) were found with Phytophthora ramorum foliar and stem infections, yet not in close proximity to Rhododendron ponticum, have more recently been found to have a range of other woodland and commercial plantation species affected by the pathogen (primarily bole canker infections). Tests conducted by UK Forest Research have shown that the Japanese larch foliage strongly supports P. ramorum sporulation, possibly even to the extent seen on California bay laurel (Umbellularia californica). Foliar infections on larch appear to be able to generate hundreds and even thousands of sporangia on a single infected needle. This inoculum load high in the crowns of affected Japanese larch has likely lead to widespread local infection on the foliage and boles of nearby susceptible tree and understory species, as well as caused bole infections on the larch.
Affected species of the larch understory include beech (Fagus sylvatica), sweet chestnut (Castanea sativa), and oak species (Quercus spp), all of which are known to suffer from bole cankers, as well as birch (Betula pendula), which has not previously been found as a bole host. Over the past 6 months a number of conifer species have also emerged as bole hosts, including western hemlock (Tsuga heterophylla), Port Orford cedar (Chamaecyparis lawsoniana), and Douglas-fir (Pseudotsuga menziesii); however, only one or two individuals of these conifer hosts have so far been confirmed P. ramorum positive. Western hemlock has also been confirmed as a foliar host of the pathogen.
This upsurge in P. ramorum and the many new hosts that are emerging is strongly correlated with proximity to larch exhibiting crown dieback. The number of sites where this is known to be occurring is limited. Control measures are now underway, which includes felling the larch to prevent further sporulation following budburst in the spring. For more information and details of symptoms, go to http://www.forestry.gov.uk/forestry/INFD-7XVEWH and http://www.forestry.gov.uk/website/forestry.nsf/byunique/infd-5vfmzu "
from the April COMTF newsletter
"The 2009 UK sites where Japanese larch (Larix kaempferi) were found with Phytophthora ramorum foliar and stem infections, yet not in close proximity to Rhododendron ponticum, have more recently been found to have a range of other woodland and commercial plantation species affected by the pathogen (primarily bole canker infections). Tests conducted by UK Forest Research have shown that the Japanese larch foliage strongly supports P. ramorum sporulation, possibly even to the extent seen on California bay laurel (Umbellularia californica). Foliar infections on larch appear to be able to generate hundreds and even thousands of sporangia on a single infected needle. This inoculum load high in the crowns of affected Japanese larch has likely lead to widespread local infection on the foliage and boles of nearby susceptible tree and understory species, as well as caused bole infections on the larch.
Affected species of the larch understory include beech (Fagus sylvatica), sweet chestnut (Castanea sativa), and oak species (Quercus spp), all of which are known to suffer from bole cankers, as well as birch (Betula pendula), which has not previously been found as a bole host. Over the past 6 months a number of conifer species have also emerged as bole hosts, including western hemlock (Tsuga heterophylla), Port Orford cedar (Chamaecyparis lawsoniana), and Douglas-fir (Pseudotsuga menziesii); however, only one or two individuals of these conifer hosts have so far been confirmed P. ramorum positive. Western hemlock has also been confirmed as a foliar host of the pathogen.
This upsurge in P. ramorum and the many new hosts that are emerging is strongly correlated with proximity to larch exhibiting crown dieback. The number of sites where this is known to be occurring is limited. Control measures are now underway, which includes felling the larch to prevent further sporulation following budburst in the spring. For more information and details of symptoms, go to http://www.forestry.gov.uk/forestry/INFD-7XVEWH and http://www.forestry.gov.uk/website/forestry.nsf/byunique/infd-5vfmzu "
from the April COMTF newsletter
HERB GARDENING ENTHUSIASTS CAN HELP DETECT INVASIVE PLANT DISEASE
HERB GARDENING ENTHUSIASTS CAN HELP DETECT
INVASIVE PLANT DISEASE
Since destructive pests are often impossible to control once established, early detection is key to stopping their spread
ARLINGTON, VA—April 7, 2010 – Until proposed revisions to the regulations governing international plant trade, currently under review, are approved by the U.S. Department of Agriculture (USDA), homeowners can play an important role in detection and reporting of invasive insects and diseases. New non-native plant pest introductions are detected at a rate of one every 12 days, adding to the burden of the approximately 400 tree pests already established in the United States. These pests can wreak havoc in homeowners’ yards, and then move through neighborhoods and to nearby forests, causing costly and widespread destruction.
The Nature Conservancy, along with nursery industry partners and scientists, is supporting these revamped regulations in its ongoing efforts to block non-native insects and diseases. If implemented, the USDA rules would create a new category called NAPPRA (Not Authorized for Importation Pending Pest Risk Assessment), under which the nation could quickly stop the import of some plants suspected of harboring pests until procedures can be implemented to ensure they are safe.
INVASIVE PLANT DISEASE
Since destructive pests are often impossible to control once established, early detection is key to stopping their spread
ARLINGTON, VA—April 7, 2010 – Until proposed revisions to the regulations governing international plant trade, currently under review, are approved by the U.S. Department of Agriculture (USDA), homeowners can play an important role in detection and reporting of invasive insects and diseases. New non-native plant pest introductions are detected at a rate of one every 12 days, adding to the burden of the approximately 400 tree pests already established in the United States. These pests can wreak havoc in homeowners’ yards, and then move through neighborhoods and to nearby forests, causing costly and widespread destruction.
The Nature Conservancy, along with nursery industry partners and scientists, is supporting these revamped regulations in its ongoing efforts to block non-native insects and diseases. If implemented, the USDA rules would create a new category called NAPPRA (Not Authorized for Importation Pending Pest Risk Assessment), under which the nation could quickly stop the import of some plants suspected of harboring pests until procedures can be implemented to ensure they are safe.
“Vigilant homeowners and gardeners have been the ones to detect the presence of foreign pests that had previously gone undetected in many areas,” says Faith Campbell, senior policy representative in the Conservancy’s Forest Health Program. “A Massachusetts homeowner, who found a strange-looking bug in her backyard and reported it to the appropriate government agency, helped prevent the Asian long-horned beetle from spreading through the United States.”
Earlier this year, an alert greenhouse owner in Pennsylvania saw odd symptoms on his seedling bay laurel or sweet bay (Latin: Laurus nobilis). Experts confirmed that the plants were infected by the pathogen that causes “sudden oak death” (Latin: Phytophthora ramorum), a disease that has killed over a million trees in California. This is not the first detection of the pathogen in Pennsylvania or the eastern United States; however, to date, there have been no detections of the pathogen in the forestry environment on the East Coast.
This disease is known to attack several kinds of oaks, magnolias, rhododendrons, and mountain laurel. Bay laurel is a popular herb often grown by gardeners. If homeowners have recently bought bay laurel seedlings or seeds, they should examine these plants carefully. If the plants have dead or dying leaf tips or the entire plants are dead or dying, those symptoms may be caused by:
· too much water
· too little water
· too much fertilizer
· chilling or freeze damage
· infection by the sudden oak death pathogen or some other disease agent
If homeowners rule out all the causes except for the presence of a disease, they should contact their state department of agriculture to find out where to send a sample of it and how it should be packaged to ensure spores cannot escape during shipment. A state’s chief plant pest regulator can be found at www.nationalplantboard.org/member/index.html.
Additionally, as homeowners nationwide begin their general yard clean-up and spring gardening, they should be aware that other plants and trees might be carrying a damaging insect or disease. If they notice any insects or a blight or disease they don’t recognize, they can take a photo or specimen of it to their local nurseries or use Internet resources such as http://invasivepests.org/photosmore.html to help them identify it. If they suspect they may have found an invasive pest or pathogen, they should contact the local government department that oversees agriculture or forestry to alert them to the discovery and gain assistance in confirming its identity.
Following are some of the most prevalent invasive insects and diseases, and the regions which are currently threatened by their encroachment.
Non-Native Pest Regions at risk
hemlock woolly adelgid ---- Appalachian Mountain region
laurel wilt & ambrosia beetle ---- coastal regions from South Carolina to Mississippi; Florida
sudden oak death ---- coastal regions of California and Oregon
Asian longhorned beetle ---- New England; New York and New Jersey; Chicago metropolitan area
More detailed information about and photos of these and other invasive pests can be found at http://www.invasivepests.org/.
###
The Nature Conservancy is a leading conservation organization working around the world to protect ecologically important lands and waters for nature and people. The Conservancy and its more than one million members have been responsible for the protection of more than 18 million acres in the United States and have helped preserve more than 117 million acres in Latin America, the Caribbean, Asia and the Pacific. Visit us on the Web at http://www.nature.org/.
The Continental Dialogue on Non-Native Forest Insects and Diseases is a group of organizations and individuals that cultivates and catalyzes collaborative action among diverse interests to abate the threat to North American forests from non-native insects and diseases.
Thursday, April 1, 2010
Phytophthora ramorum has been detected in Pennsylvania on Bay (Laurus nobilis)
Another pathway by which P. ramorum can be introduced is described below:
"On Feb. 18, 2010 the Penn State Plant Disease Clinic received a sample of Laurus nobilis, known commonly as bay laurel, true laurel, sweet bay,laurel tree, Grecian laurel, or bay tree. Some people use its leaves in cooking. The tips of the leaves submitted were dead or dying and it was reported by the grower that 95% of well rooted plants in 12 or so flats exhibited the symptoms. The United States Department of Agriculture-Animal Plant Health Inspection Service (USDA-APHIS) confirmed the plants to be infected with Phytophthora ramorum, the Sudden Oak Death pathogen known to occur in trees and shrubs on the west coast of the U.S. and in Europe. The sample came from a commercial, primarily wholesale, greenhouse in eastern Pennsylvania. Phytophthora ramorum can infect many important ornamental trees and shrubs under the right conditions. There is a great deal of concern that this fungus-like organism could cause significant economic damage to eastern forests and landscapes if not excluded from the region.The’ bay laurel’ submitted was not Umbelluiaria californica, the California bay or California bay laurel that grows on the west coast and is a major host of Phytophthora ramorum that then spreads to oaks. However, Laurus nobilis is known to be a host of Ph. ramorum.The actual source of the Ph. ramorum in Pennsylvania is still under investigation and is very much in question. The infected plants had been grown in Pennsylvania from seed obtained from a source in California. As yet, there are no known cases of Ph. ramorum being seedborne. I learned recently that the ‘seed’ is sometimes received not as cleaned seed but as seed still in the drupe (fruit). That raises the possibility that the pathogen may have been in parts of the fruit other than the actual seed. It is also possible that the pathogen was infecting other plants in the greenhouse and spread to the Laurus. APHIS is doing ‘trace backward’ investigations to determine where the pathogen may have come from and‘trace forwards’ to determine whether various plants sold by the Pennsylvania greenhouse are carrying the pathogen.
Phytophthora ramorum has, to date, been excluded from the eastern U.S. but this occurrence may indicate that the plant pathogen is now or will soon be in the region from multiple sources. In 2009, Laurus nobilis was named as the Herb of the Year by the International Herb Association (IHA). Laurus nobilis seed can be purchased from a number of sources including through Amazon.com. Web information indicates that the seed is difficult to germinate. It is my understanding that people have been encouraged to grow this plant and that it has been used in various Master Gardener projects. If seed or tissue associated with seed is actually the source of the pathogen, it is possible that Phytophthora ramorum has arrived in the east with seed purchased bybackyard gardeners, etc. Where is the ‘failed to germinate’ material discarded? Where are plants with dying leaf tips discarded? The photo below (and attached) is of the actual sample as it arrived at Penn State. It is not very impressive. If you are presented with Laurus nobilis plants with dead or dying leaf tips or entire plants dead or dying…those symptoms may be caused by:
too much water
too little water
too much fertilizer
chilling or freeze damage
Phytophthora ramorum infection
There is much we don’t know about the circumstances surrounding this occurrence and, therefore, we can’t release specifics such as the name of the greenhouse. But, the information above can be used in newsletters,training sessions, news releases, grower presentations, etc."
Gary W. Moorman, Prof. of Plant Pathology
The Pennsylvania State University, Department of Plant Pathology
Wednesday, March 3, 2010
Shift in Phytophthora ramorum populations in Washington State
The EU1 strain is now the most common P. ramorum lineage detected in WA state nurseries and non-nursery sites, with a concurrent rise in NA2 and decrease in NA1. Evaluation of genotypes over the past 5 years by Gary Chastagner, Katie Coats, and Marianne Elliott at Washington State University shows the reversal in genotype frequency occurred in 2008 and persisted into 2009. They detected EU1 in 99 positive samples at seven locations, NA1 in 17 samples at four sites, and NA2 in 48 samples at three sites in 2009. In contrast, the first year of the study (2005) identified four EU1 samples at one site, 103 NA1 samples at 14 sites, and 12 NA2 samples at five sites.
Of the 46 Washington nurseries found positive since 2003, five had infected plant detections in 2009. Twenty nurseries have been confirmed positive at least two years. Two of these sites were found to have positive plants three different years and two sites were positive four years. Genotype analysis has been performed on samples from 31 nurseries since 2005. Of the nurseries with multiple confirmed years, six had various combinations of two lineages for one or two years and one had a year with all three lineages followed by two other years with two lineages present each year.
Nine Washington non-nursery sites (landscapes, water, soil or trace-forward landscape plants) have also been identified P. ramorum positive since 2005, with seven sites having been positive in 2008 and/or 2009. Of the seven sites, the Rosedale Stream (Pierce County) has been found positive for four years (NA1) and the Sammamish River (King County) has been confirmed positive for three years (several lineages). A Pierce County site with NA2-positive salal plants was also found adjacent to nursery property, and four residential sites have been found in the past two years, all of which have been identified with the EU1 strain (two residences were found with the EU1 strain in 2008 and 2009, one with plants and soil, and one with just soil). These four residential sites were trace-forwards from the same EU1-positive nursery.
In 2009, a new systematic sampling method was implemented, which involved not only genotyping the original DNA sample, but also a second round of sampling using the same plant and/or bait material from which the DNA positive was detected. In addition, through a cooperative effort with the Washington State Department of Agriculture and the USDA Animal and Plant Health Inspection Service (APHIS), a third round of sampling was performed on whole plants or plant material collected from most of the nurseries prior to destruction of the plant material. This duplicate and triplicate sampling allowed for a better representation of the genetic distribution of the P. ramorum population.
In total, 450 samples from 31 nurseries, three water sites, and six landscape locations have been analyzed. For more information on the study and its findings, contact Gary Chastagner at chastag@wsu.edu.
From the COMTF March newsletter
Of the 46 Washington nurseries found positive since 2003, five had infected plant detections in 2009. Twenty nurseries have been confirmed positive at least two years. Two of these sites were found to have positive plants three different years and two sites were positive four years. Genotype analysis has been performed on samples from 31 nurseries since 2005. Of the nurseries with multiple confirmed years, six had various combinations of two lineages for one or two years and one had a year with all three lineages followed by two other years with two lineages present each year.
Nine Washington non-nursery sites (landscapes, water, soil or trace-forward landscape plants) have also been identified P. ramorum positive since 2005, with seven sites having been positive in 2008 and/or 2009. Of the seven sites, the Rosedale Stream (Pierce County) has been found positive for four years (NA1) and the Sammamish River (King County) has been confirmed positive for three years (several lineages). A Pierce County site with NA2-positive salal plants was also found adjacent to nursery property, and four residential sites have been found in the past two years, all of which have been identified with the EU1 strain (two residences were found with the EU1 strain in 2008 and 2009, one with plants and soil, and one with just soil). These four residential sites were trace-forwards from the same EU1-positive nursery.
In 2009, a new systematic sampling method was implemented, which involved not only genotyping the original DNA sample, but also a second round of sampling using the same plant and/or bait material from which the DNA positive was detected. In addition, through a cooperative effort with the Washington State Department of Agriculture and the USDA Animal and Plant Health Inspection Service (APHIS), a third round of sampling was performed on whole plants or plant material collected from most of the nurseries prior to destruction of the plant material. This duplicate and triplicate sampling allowed for a better representation of the genetic distribution of the P. ramorum population.
In total, 450 samples from 31 nurseries, three water sites, and six landscape locations have been analyzed. For more information on the study and its findings, contact Gary Chastagner at chastag@wsu.edu.
From the COMTF March newsletter
New species added to the host list
Ten species have been added to the list of federally regulated P. ramorum associated host plants. The USDA Animal and Plant Health Inspection Service (APHIS) issued the on 2/22/10, adding Mexican-orange (Choisya ternate), kousa dogwood (Cornus kousa), Daphniphyllum glaucescens, European holly (Ilex aquifolium), Japanese-oak (Lithocarpus glaber), Magnolia cavalieri, Magnolia foveolata, bayleaf currant (Ribes laurifolium), bilberry (Vaccinium myrtillus), and lingon berry (Vaccinium vitis-idaea) to the list. Symptoms for each of the new hosts other than bilberry were leaf necrosis. Tip dieback occurs in infected bilberry as well as Daphniphyllum glaucescens These species were identified as susceptible by the Canadian Food Inspection Agency (CFIA) and the United Kingdom's Food and Environment Research Agency (FERA).
Nurseries currently operating under an APHIS P. ramorum compliance agreement are able to continue shipping hosts and associated plants, including the newly listed plants; however, any nurseries not currently under a compliance agreement that contain these new species must be properly inspected, sampled, tested, and placed under a Compliance Agreement by 3/31/10 in order to be able to move any plants interstate.
From the COMTF March newsletter
Nurseries currently operating under an APHIS P. ramorum compliance agreement are able to continue shipping hosts and associated plants, including the newly listed plants; however, any nurseries not currently under a compliance agreement that contain these new species must be properly inspected, sampled, tested, and placed under a Compliance Agreement by 3/31/10 in order to be able to move any plants interstate.
From the COMTF March newsletter
Monday, February 15, 2010
News from California and the rest of the US
Warm, wet weather caused by El Nino is a "free ticket to Disneyland" for P. ramorum in California, providing an environment in which the disease can spread:
http://www.napavalleyregister.com/lifestyles/home-and-garden/columnists/bill-pramuk/article_60416e9e-184e-11df-bfaf-001cc4c002e0.html
Researchers at University of North Carolina are developing a model to predict spread of P. ramorum if it were to get loose in the eastern US:
http://www.newsobserver.com/news/local_state/story/314528.html
http://www.napavalleyregister.com/lifestyles/home-and-garden/columnists/bill-pramuk/article_60416e9e-184e-11df-bfaf-001cc4c002e0.html
Researchers at University of North Carolina are developing a model to predict spread of P. ramorum if it were to get loose in the eastern US:
http://www.newsobserver.com/news/local_state/story/314528.html
Tuesday, February 9, 2010
NA2 lineage found on salal, additional positive nurseries
As part of the perimeter survey conducted at a P. ramorum-positive retail nursery in Pierce County, Washington last summer, the Washington State Department of Agriculture identified infested salal (Gaultheria shallon) plants in the natural landscape (as reported in the COMTF August 2009 Newsletter). Follow-up analysis of the samples by the Chastagner lab at Washington State University has resulted in the isolation of the NA2 lineage from the salal. This is the first detection of the NA2 lineage on native forest vegetation. For more information on this development, contact Gary Chastagner at chastag@wsu.edu.
Washington had two P. ramorum-positive locations identified in January. Both sites have previously been found positive for the pathogen. One positive find was in retention pond water at a Pierce County retail nursery. Treatment of the pond (located on nursery property) is optional as it is not used for irrigation or fire suppression. The second site was in a Mason County church landscape where an assumed-positive Viburnum tinus was identified as part of a Thurston County nursery trace-forward investigation. Follow-up efforts have determined that the viburnum did not transit through the Thurston County nursery, but rather was sourced from Oregon. It is unknown where the plant potentially became infested. The Oregon nursery from which the plant originated completed the CNP in December (2009). WSDA PCR results on the viburnum were inconclusive; results are pending from Beltsville, MD.
From the February COMTF newsletter
Washington had two P. ramorum-positive locations identified in January. Both sites have previously been found positive for the pathogen. One positive find was in retention pond water at a Pierce County retail nursery. Treatment of the pond (located on nursery property) is optional as it is not used for irrigation or fire suppression. The second site was in a Mason County church landscape where an assumed-positive Viburnum tinus was identified as part of a Thurston County nursery trace-forward investigation. Follow-up efforts have determined that the viburnum did not transit through the Thurston County nursery, but rather was sourced from Oregon. It is unknown where the plant potentially became infested. The Oregon nursery from which the plant originated completed the CNP in December (2009). WSDA PCR results on the viburnum were inconclusive; results are pending from Beltsville, MD.
From the February COMTF newsletter
Tuesday, February 2, 2010
Japanese larch and Western hemlock new hosts for P. ramorum in the UK
"Since August 2009, significant numbers of Japanese larch trees have begun to show symptoms of needle loss and dieback in Devon, Cornwall and Somerset. The number of trees affected, and the apparent speed of the decline is a cause for concern – some trees are already dead. Smaller numbers of broadleaf trees associated with the larch were found to have symptoms of bleeding cankers, and closer examination by Forest Research scientists revealed that these broadleaf trees were infected with Phytophthora ramorum. This is the fungus-like pathogen responsible for the phenomenon known as “sudden oak death” in the USA, where it has killed millions of trees including the native American tanoak. "
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