Re: [gardeners] Magnolia Soulangeana wilting problems

Dan Dixon (gardeners@globalgarden.com)
Thu, 09 May 2002 13:08:25 -0500

Sherryl Fawx at slfawx@ucdavis.edu wrote:

> I suggest asking your local ag extension specialist or calling in an
> arborist.  Phytophthora and armillaria are both fungal pathogens causing
> disease.  Armillaria root rot is also known as oak root fungus or
> shoestring fungus and affects many broadleaf trees and conifers.  It
> infects and kills cambial tissue, causing major roots and the trunk near
> the ground to die.  Phytophthora kills the roots and root crown area of
> infected plants. 
> I would definitely not call them beneficial.
> 
> -Sherryl (suspicious of "elixirs")
> Davis, Calif.

Following up on this... I've read a bit about various phytophthora and
armillaria fungi, but have not found any discussion of these affecting
Magnolia. Symptoms I see do seem to indicate some kind of fungus may be
present though. Best I can tell, treatment options are few, with "protective
fungicide drenches" being the most frequently mentioned. Anyone have
experience with these drenches? Phenylamide fungicides were said to be
effective against root rots, with Metalaxyl supposedly having curative as
well as protective activity.

Thanks in advance for any advice/info.

Dan Dixon