"dave weil" wrote in message
news
On Fri, 11 Jul 2003 08:05:49 GMT, "Allegra"
wrote:


I discussed this very issue with the main gardener at Edmunds Roses.
He claims that the bacteria is ever-present in many soils but that
most of the time, it isn't activated or doesn't get the chance to
infect the plant. So, he's not all that sure that sterilization or
even quarantine does a lot of good. So, there might not be a lot of
worry about spreading, since, if you get it in the first place, it's
probbly everywhere in your soil anyway. Just be careful about nicking
the other plants at crown level, since that's the main event of
opporunity that allows gall to start.

He also said that he keeps some 40 galled roses out of the 800 that he
grows as evidence that it doesn't have to be an immediate killer. He
says that some of them are quite impressive. He also realizes that it
will probably eventually weaken the plant, but some of them have been
around for over 10 years with gall.

Just thought I'd share this anecdotal info.

Curious choice, knowing that the pathogen spreads
with the usage of tools and it has been proven to
be vectored through infected rootstock accidentally
- see the following link- as discussed at the III International
Symposium on Rose Research and Cultivation

" This study represents the first demonstration that
the exponential spread of crown gall disease in Mediterranean
rose cultures is due: to the vegetative propagation of rootstocks,
to the frequent exchange of plant material between professional
breeders, multipliers and grafters, and to the increasing turnover
rates for flower production. As an efficient chemical or genetic
control of the disease will not be applicable in the near future,
a further propagation of disease can be reduced only through
selection of healthy rootstocks. "

http://www.actahort.org/books/547/547_9.htm

Since symptoms of the disease are slow to show it would seem
a dangerous thing to do, and one suspects that the transmission
can be effected to other roses that may very well leave their garden
being infected without them knowing it and end in someone else's
garden where they would take residence in the soil awaiting a
single puncture from any source to infect a healthy plant.

It makes for very interesting reading to check different sources
particularly now on the Web. In the old days it was the library,
the colleges' libraries and a trip down to Eugene if you wanted
to find the papers. The folklore was always available.

Allegra