Phytophthora ramorum

Has anyone seen this story ??


http://www.forestry.gov.uk/newsrele.nsf/AllByUNID/11FB60906B36B2C68025773D005CD276

Very worrying indeed Tim. Especially as its infecting native flora. Lets hope they contain it but going by past disease outbreaks,difficult and near impossible.

Thanks for that link Tim. I had heard a short piece on the radio but this clarifies it. We'd better keep our eyes peeled for any health issues with Japanese larch bonsai.

If any of your Larches dies unexpectedly, burn it!

Not Good! I doubt it will stop at larix!

Thousands of trees are being felled in Somerset this week (August 2010) Quantock hills especially.....which is just a mile from me. My 80 year old prize winning Larch is sat with branches firmly crossed.

News today by the forestry commission /BBC news.

http://www.bbc.co.uk/news/uk-england-somerset-10997439

Very worrying not just because of my own trees but on national and intentional scale.

I also notice horse chestnuts looking very poorly indeed.Bleeding Canker I believe it is called. Sadly many local trees are now affected.

Mike

ANOTHER reason to be careful about planting exotic species where they don't belong. They always will be susceptible to the new bugs they meet. When they become badly infected, the infection can spread just because there is so much of it around.

Phytophthora is awful stuff. If you trees get it, the BEST solution is disposal as far from your tables as possible, then alcohol sterilization of pots and tools.

JimLewis wrote:ANOTHER reason to be careful about planting exotic species where they don't belong. They always will be susceptible to the new bugs they meet. When they become badly infected, the infection can spread just because there is so much of it around.

Phytophthora is awful stuff. If you trees get it, the BEST solution is disposal as far from your tables as possible, then alcohol sterilization of pots and tools.

If only it had been that simple Jim. Experts suggest it emanated from possibly Asia or parts of the USA. Sadly it can be carried by air currents and misty rain among many other means of transfer.

Meanwhile the UK gains much knowledge from the USA in so far as how they have managed to contain it...or not as the case may be.

http://en.wikipedia.org/wiki/Sudden_oak_death

This is worrying indeed! Phytophthora ramorum appeared here in California in 1995 where it is commonly known at Sudden Oak Death. It has had a devastating impact on our many native species of Oak and also Tanbark (Lithocarpus). Here it can infect a wide diversity of trees in both natural forests as well as in horticultural situations including Rhododendron, Arbutus, Vaccinium, Umbellularia, Aesculus, Acer, Heteromeles, Arctostaphylos, Sequoia, Pseudotsuga, Rhamnus to name a few. On most of these it causes a less sever disease often called Ramorum Blight of Ramorum Die-back.

To the best of my knowledge, the pathway of introduction of the pathogen into California is still unknown, but international trade in Rhododendron is suspected. Certainly the shipment of infected rhododendrons in the nursery trade has contributed to its spread in the state.

At this point there are few controls for the disease; the most effective is early detection, disposal of infected material, and good growing area sanitation.

I am not a plant pathologist so I will not comment further and allow those with more knowledge to chime in. However, I can attest that there are significant resources flowing to research into effective controls for this disease both in nursery and garden situations as well as wildlands.

David B.

It is also very low-priced imports from Germany, I spoke with a forester to be reckoned with here in the visible for at least 5 years, all this know-mouth disease and the history that was blowing in relation to the Ministry of Environment.

Lethal tree disease Phytophthora ramorum has been found in Japanese larch in Northern Ireland for the first time. The disease can cause serious damage to larch trees and the environment. Infected with Japanese Larch and the public and private land is reversed.

dominicjoe wrote:Lethal tree disease Phytophthora ramorum has been found in Japanese larch in Northern Ireland for the first time. The disease can cause serious damage to larch trees and the environment. Infected with Japanese Larch and the public and private land is reversed.

Sadly just one mile away from me.

Mike

David Brunner wrote:This is worrying indeed! Phytophthora ramorum appeared here in California in 1995 where it is commonly known at Sudden Oak Death. It has had a devastating impact on our many native species of Oak and also Tanbark (Lithocarpus)...

Needless to say the prospect of Sudden Oak Death has us really worried in the coastal South. It's hard to imagine the South without Live Oaks. The reason we bought our house...

I'll be seeing Dr. Nina this week. She spends the days of her life studying Sudden Oak Death for the USDA and is here attending a conference on the subject in Hendersonville, NC. We'll be discussing the state of the science, I'm sure. I'll ask her to take a look at this thread when she returns to her labs. Maybe she can contribute something positive.

But info I've had from her in the past on this indicates that destroying the affected plant is the only solution.

You folks with Azaleas need to be cautions, too. They're quite susceptible.

Sadly it can be carried by air currents and misty rain

Not between North America and the British Isles, I suspect.

Nina says having this stuff in the UK is worrying a lot of people. Lots of work being done. Not too many answers yet.

She also said that it is "very unlikely" that it wold ever affect a bonsai.

Aliete 80WG is licensed for the treatment and control of a number of phytophthora strains. It is also used in food production.
It is a very potent fungicide and can only be purchased and applied by licensed persons. It works as a preventitive and kills a phytophthora spores on contact.

There are dozens of different phytophthera strains but this is known to be effective against some - research is still expanding.

http://www.certiseurope.nl/binarydata.aspx?type=doc/Aliette%2080WG%20A5%20.pdf

http://www.certiseurope.co.uk/binarydata.aspx?type=doc/Aliette%2080WG%20MSDS%20131108.pdf

http://mrec.ifas.ufl.edu/foliage/resrpts/rh_92_9.htm

Aliete 80WG is potent stuff, its toxic to us but breaks down quickly in the environmeny, it should only be used by approved persons.

Hello from beautiful Hendersonville! I had lunch with Jim Lewis, which is always a good idea, and which always means good beer.

As far as the outbreak in England in Larch is concerned, I don't see a change in the risk to bonsai. The disease has been in European nurseries for years, and it caught Europeans by surprise when the disease suddenly showed up on really tall larch.

In the US, there has been one report on a bonsai, and ironically, it was on a mallsai sitting indoors where it was no danger to anyone, and would have dried up and died on its own. I would advise everybody not to move known hosts out of an affected region. In the US, that means not taking an oak bonsai (or camellia or manzanita or madrone or buckeye) out of any of a number of counties in California. Nurseries in those counties are not allowed to ship out of state without an inspection to show they are free of the disease, but that certification does not guarantee that you won't get a plant with an invisible infection (That's what I study- invisible infections!). So in the US I wouldn't buy those kinds of plants from certain nurseries. In Europe, the situation is more complicated, because the disease is widespread in nurseries, but not wide-spread in nature. That means your bonsai in your backyard in Belgium or Italy is not going to get the disease, but you might buy an infected lilac or Camellia or Rhododendron from a nursery.

Aliette is NOT effective against P. ramorum. All systemics on the market are "fungistats" which means they only slow growth of the pathogen.

For US people, you can go to the website of the California Oak Mortality Task Force -- http://www.suddenoakdeath.org/ -- for a huge amount of good information. For Europe, the DEFRA website is outstanding. (Note: I searched the DEFRA website and found no useful info - Jim Lewis; I always could have missed it. www.defra.gov.uk/)

[postscript to Iris Cohen: I can answer your question now after cornering the two US authorities on crown gall. Right now there is a lot of crown gall infesting US production nurseries, but figs are infected by a different species of bacterium than most other plants, so the risk is really of buying plants where shoddy production practices are standard procedure.}

Thanks, Nina . . . and we expect a picture of you relaxing in your new rustic rocking chair.

Sorry to be contentious, but I didn't say or suggest that Aliete 80WG is effective against P Ramorum.

I understand that there are 16 or more strains of Phytophthora most of which are of no worry to bonsai as they attack potates or strawberries

The one which I understand has most potential to attack bonsai is Phytophtora Cinnamomi which likes acid loving conditions and can attack azaleas and other similar trees. The fungicides developed specifically for this group are the Phosphonates of which Fosetyl Aluminium is one. Fosetyl aluminium is the major constituant of Aliette 80wg.

I suggestd that it was effective in the conrtrol of some strains and killed Phytophthora spores, which according to the literature it does.

The following papers both recomend Aliete 80wg for the control of P Cinnamomi

http://www.plantmanagementnetwork.org/pub/php/research/2006/fraser/

http://ohioline.osu.edu/hyg-fact/3000/3073.html

The literature sais , Aliete signficantly enhances the trees own inate resistance and provides external control.

This is the quote which interested me.

The discovery of the unique downward systemic transport properties of these phosphonate fungicides was of great
significance for the control of soil-borne diseases caused by Phytophthora. Fosetyl-Al is the only commercially available fungicide known to be systemically transported in a downward direction in plants. This property permits the fungicide to be applied to foliage
or tree trunks in order to control root diseases caused by Phytophthora.

Nina, Can you confirm if this is correct or am 'I barking uo the wrong tree' no pun intended.

And I didn't mean to imply that Aliette was useless, but it only slows the growth of Phytophthoras- it doesn't kill them, so it is useful if you need to keep a crop going until you harvest the crop- potatoes is a good example, or (if you are an unscrupulous nursery grower) to keep a plant looking healthy until you can sell it.

The best thing to do to keep away Phytophthoras is to watch your use of water. Use well-draining soils. Keep foliage dry as much as possible.

I have a lot of interesting news from this meeting (The Kanuga Ornamental Workshop)- I will try to post some of it when I get back home.

I lost a nice, small azalea which I imported legally from Japan on a trip there in 2004. A few years later it developed necrotic leaves/branches which the local county extension agent felt was possibly Phytophthora blight. I tried many fungicides including Alliet to no avail.

I have a lot of interesting news from this meeting (The KanugaOrnamental Workshop)- I will try to post some of it when I get backhome.

Look forward it, but enjoy you vacation first.

For general information check out item 16 from the website below. I think it gives a good insite into this horrible problem

http://www.satsuki-azalea-society.org.uk/Phytophthora(0.2).pdf

please wash your hands after reading it.
regards
Barrie