Phytophthora?
 

Our large old Camellia has some problem that is causing it's old leaves to
fall before their usual time, I'm not convinced it's Phytophthora as the
necrosis does not spread down the midrib of the leaves, that is the last
place to die. First noticed this problem about 2 years ago.
I've uploaded some photos I took today at....

http://www.flickr.com/photos/bobhobd...7626110259390/

Another lily flowered Camellia about 15ft away is unaffected as is "Madame
de Strekaloff" in the front garden.

What do the experts think, Phytophthora or a virus or something else?

--
Regards
Bob Hobden
W.of London. UK

Phytophthora?
 

On Tue, 22 Feb 2011 15:18:53 -0000, "Bob Hobden"
wrote:

Our large old Camellia has some problem that is causing it's old leaves to
fall before their usual time, I'm not convinced it's Phytophthora as the
necrosis does not spread down the midrib of the leaves, that is the last
place to die. First noticed this problem about 2 years ago.
I've uploaded some photos I took today at....

http://www.flickr.com/photos/bobhobd...7626110259390/

Another lily flowered Camellia about 15ft away is unaffected as is "Madame
de Strekaloff" in the front garden.

What do the experts think, Phytophthora or a virus or something else?

Have you tested the pH of the soil around the camellia? I had one go
like that a while back and cured the problem once I'd discovered that
the pH of the soil had changed.

AFAIK, the kernoviae variant of the dreaded "P" is the only one that
would attack a camellia but that's (again AFAIK) currently confined to
Cornwall and, dammit, South Wales! If you want to be sure", you can
get a kit from the link below that tests for all forms of it. I lost a
rhododendron and was worried as "P"s been found not far from me and it
sort of looked right as the culprit. The test reassures if nothing
else and in my case avoided the complications arising from discovery.

http://www.pocketdiagnostic.com/products/31

Phytophthora?
 

In article , says...
Our large old Camellia has some problem that is causing it's old leaves to
fall before their usual time, I'm not convinced it's Phytophthora as the
necrosis does not spread down the midrib of the leaves, that is the last
place to die. First noticed this problem about 2 years ago.
I've uploaded some photos I took today at....

http://www.flickr.com/photos/bobhobd...7626110259390/

Another lily flowered Camellia about 15ft away is unaffected as is "Madame
de Strekaloff" in the front garden.

What do the experts think, Phytophthora or a virus or something else?


Bob, I don't think its Phytophthora, the die back is the other way
around, with Phytophthora the die back spreads up the mid rib first.
Virus or scale might be worth checking for although there is not much you
can do about either
--
Charlie Pridham, Gardening in Cornwall
www.roselandhouse.co.uk
Holders of national collections of Clematis viticella cultivars and
Lapageria rosea

Phytophthora?
 

Am 22.02.2011 16:18, schrieb Bob Hobden:
I've uploaded some photos I took today at....

http://www.flickr.com/photos/bobhobd...7626110259390/

Can you unequivocally exclude simple sunburn? e.g.
http://www.kamelien.de/magazin/nr03/sonne.htm

Cheers
Gotthelf

Phytophthora?
 

On Feb 23, 11:33*am, Janet wrote:
In article ,
says...







On Tue, 22 Feb 2011 18:24:44 -0000, Janet wrote:

In article ,
says...

On Tue, 22 Feb 2011 15:18:53 -0000, "Bob Hobden"
wrote:

Our large old Camellia has some problem that is causing it's old leaves to
fall before their usual time, I'm not convinced it's Phytophthora as the
necrosis does not spread down the midrib of the leaves, that is the last
place to die.

*Phytophthera doesn't always spread down the midrib, we often see it as
random *spots here. This has some good pics

http://www.fera.defra.gov.uk/plants/.../factsheets/ph
ytophthoraKernoviaeFactsheet.pdf

*Your pics don't look like any of the phytophthera I've seen up here.

AFAIK, the kernoviae variant of the dreaded "P" is the only one that
would attack a camellia but that's (again AFAIK) currently confined to
Cornwall and, dammit, South Wales!

* Wrong on both counts I'm afraid, camellia IS one of the
hostplant/victims to p ramorum

http://www.plantmanagementnetwork.or...2006/camellia/

and p kernoviae has been active here in Scotland (Arran) for at least 3
years... first noticed here in *2008.

http://www.scotland.gov.uk/Resource/Doc/915/0103583.pdf

*Janet (Arran)

Thanks Janet. My info was from a mix of Forestry Commisison docs and a
chat with a helpline when researching my almost-dead rhododendron last
year. As a result, I've only been keeping an eye on the spread of
kernoviae variant but will now watch ramorum as well.

* * Professional gardeners here, are of the opinion that *ramorum and
kernoviae are uncontainable; and almost certainly far more wide spread
than is officially *recorded. Not just because of the nature of their
infectivity, but because the draconian official consequences imposed on
the owners of infected plants are a serious disincentive to
notification.

* Janet.- Hide quoted text -

- Show quoted text -

Well usually when alien species are 'discovered' to be causing trouble
by the powers that be, it transpires that the organism has been
present but overlooked for some considerable time. They then make a
fruitless show of attempts at containment, just going through the
motions and even talk of eradication for a while before turning their
attention to control if it turns out to be required.
The most recent example of this that I have been personally involved
with was the Varroa mite of honeybees.
So I tend to agree with your professional contacts.

Rod