Anyone heard about this?
http://www.capitalpress.com/Or.....quarantine
Bacteria discovery prompts Oregon quarantine
Capital PressA quarantine in nine Oregon counties will restrict plant shipments due to the discovery of Xylella fastidiosa, a bacterial pathogen.
The discovery of a bacterial disease, Xylella fastidiosa, has convinced Oregon’s farm regulators to order a quarantine restricting shipments of susceptible plants from nine counties.
The pathogen causes symptoms similar to drought stress and often kills affected plants, as no treatments are available, said Helmuth Rogg, director of the Oregon Department of Agriculture’s plant program area.
A pear nursery in Hood River County first reported disease symptoms earlier this year, which researchers from Washington State University found were caused by Xylella fastidiosa, he said.
The Oregon Department of Agriculture was initially unable to replicate these results but eventually confirmed the bacteria’s presence after refining its test procedures, Rogg said.
The agency then found that pear trees from the National Clonal Germplasm Depository in Corvallis, Ore., were infected with the bacteria and that pear scion wood from that facility had been sent to 22 sites in the state, he said.
ODA is now trying to trace the disease’s source and where else infected plant material may have been shipped.
It’s also issued an emergency quarantine for the nine counties where the pear tree scions were shipped: Benton, Hood River, Jackson, Lane, Linn, Marion, Multnomah, Washington and Yamhill. Violating the quarantine is punishable by fines of up to $10,000.
While the bacteria has so far been associated with pear trees, the quarantine prohibits shipments of any host plant material, including oak, maple, blackberry, caneberry, blueberry and stone fruit, said Rogg.
That restriction remains in place until either the counties are found free of the disease or the bacteria’s presence is determined not to exist at a particular nursery production site, he said.
If ODA nursery inspectors do detect the bacteria, affected plants must be destroyed and the surrounding 10 meters around them will be surveyed for further evidence of the pathogen.
Insects that suck sap from plants, such as the glassy-winged sharpshooter in California, are known vectors for the bacteria’s spread, Rogg said.
Disease caused by Xylella fastidiosa has devastated olive orchards in Italy and threatens California wine producers, he said.
Oregon’s climate has traditionally been considered too cold to harbor the bacteria, which is likely why it hasn’t been found in the state until now, he said. With the prospect of warming temperatures, however, the concern is that Xylella fastidiosa will be able to survive here.
The recent discovery will postpone shipments of plant material to Europe until ODA and the USDA’s Animal and Plant Health Inspection Service are able to demonstrate the existence of pest-free areas or production sites, Rogg said.
Cort Brazelton, whose family runs the Fall Creek Farm & Nursery near Lowell, Ore., said he’s optimistic that ODA’s efforts will allow his company to ship blueberry plants to Europe next year.
“We feel confident we’ll be able to comply with all the requirements,” he said.
Brazelton said he’s happy to follow additional steps to ensure that Xylella fastidiosa doesn’t spread to customers in Europe.
“You’d always rather have no barriers but it’s important that individual counties that don’t want pathogens have reasonable protocols so that they don’t come in,” he said. “We do have to comply with the higher global standards because we ship all over the world.”
John, if I understand correctly, for the most part viruses in plant material can not be cured. If a tree is virus infected, that's permanent. In some cases, viruses can be eradicated in tissue culture, to produce new plants that are virus free.
Bacterial infection in plants, I'm not as sure about. I suspect for the most part they can't be cured from infected tissue, but the infected tissue can be removed.
Unfortunately, in both cases, there can be reservoirs of infection in the environment. The viruses require life plant tissue to persist, which can sometimes be a different plant species. Some bacteria may persist free of live plants.
This is my thought as a plant amateur. I welcome correction or fine tuning of these thoughts.
Jafar, has HOS received scion from OSU? That would double my concern.
Bacterial compost tea gets rid of a lot of bacteria disease on plants. It wouldn't kill all of the bacteria in a plant, of course, but it stops it from controlling the tree and puts it back into a balance if it is off. I have saved $1000's from using it over time. Black dead looking trees that just magically rejuvenated. Since then, my maintenance activities have prevented it from getting that bad.
John S
PDX OR
I think I hear what you're saying John. Is it that spraying compost tea on diseased plants ahead of bad bacterial pressure weather can signal the plant to ramp up days in advance of something worse, like a flue shot? and it actually works on fruit trees? I always wondered if you found a way to increase production on your bush prunus (jacki plum?). Before I always thought it was for tomatoes.
You remind me lots of an Alaska friend who saves lots using his own garden source of strong tabbaco plant as an insect killer. Which causes death to the insect immediately and don't take their time like ones you pay for. So I guess the trade-off is more training. For example in the case of insects, to then have to wash nicotine off.
If pear rootstock can't be made available I found a new hybrid apple works under or over pears called Palmetta. But it's truly not apple but a hybrid between Siberia crab (bacatta) and wild malus (neidwinski) the latter being identified as a group under the link (wild pears apples etc.) you provided a few months ago. It originated from the Siberian Botanical gardens and has been the only malus I have ever tested to show better results than my Winter Banana under pear.
I learned about compost tea from Elaine Ingham et al. You make very diverse and oxygenated microbes, which will actually enter the plant. They can outcompete disease microbes, whether as a preventative or after it has already been diseased. You can't spray in daylight. There are many details, but it works, it's cheap and it is non toxic.
John S
PDX OR
Key Words "can outcompete".
Thanks for straightening me out and it makes sense to me now after reading some of her work. Which in the case of anaerobic and oxygen requiring bacteria (ie. bacterial PPS syringae, our common enemy) it "may" be effective by hogging up food reserves excreted by the leaves of plants.
Plants are so smart that you can never know why they feed surface bacteria. PSS is considered mild to a healthy plant and hopefully some day Elaine or one of us gets to ask a plant if PSS is farmed by the plant on purpose as a guard to more harming powerful microbes.
I don't know about compost tea, but there was a recent report stating that Americans should wash their hands less, so that we become populated with more beneficial bacteria to reduce disease. The authors singled out gardeners and dog walkers as people who should wash hands less.
http://www.telegraph.co.uk/new.....teria.html
Back to the fruit trees, I am going to avoid adding any new pears to my trees this year. I want to graft some pollinizers, and will use scion from the multigraft in my back yard as a source. The labels wore out years ago, so I don't know which branch is which - there is Bartlett, Red Bartlett, Comice, and 2 others.
Good news. The Ag department gave us the go-ahead to get pear rootstock. We'll have scions from Nick Botner's collection and also a local nursery that aren't in the quarantined counties. So the selection won't be as big as usual, and we'll have fewer root-stocks, but there still should be a decent selection.
No pears from the Repository this year.
Idyllwild
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