Fwd: A plant disease question

[Thomas E. Jacobs]

<<The Arisaema rust is covered in detail in the Arisaema-L Archives
<http://listserv.surfnet.nl/archives/arisaema-l.html>. Just search on
"rust".
The organism is identified and some suggestions on how to deal with it are
made.

Ray>>

I just got depressed digging out some rust-infected triphyllum and one
sikokianum so got ambitious for a change and decided to sort of compile the
bits and pieces of info on rust back to item #000877 (dated 98/01/19) in the
archives. There is conflicting info but this is the price of biology and I
guess its principals don't have the time or money for all the properly
controlled studies they might like to do.

Arisaema rust is Uromyces ari-triphylli and is widespread in Canada and the
US. Our members report it on (at least) triphyllum, dracontium, ringens, and
sikokianum. A reference by one Pascal Pirone says that it is systemic but
does not affect roots or corms. (This seems to me to be a conflict).

Dr. Jack Parmelee ( an honorary research associate in the Biological
Resource Program for the Eastern Cereal & Oilseeds Research Centre, Canada)
http://listserv.surfnet.nl/scripts/wa.exe?A2=ind9801&L=arisaema-l&P=R1311
says that the rust is "autoecious" (spending its entire life cycle on one
host), and that there is no alternate host involved. He says that the spores
are borne aerially and that an uninfected population would not be safe 500
feet away from an infected population. He recommends removing and destroying
the entire plant, corms and all. He says it is known to affect Arisaema and
Pelandra.

Some of our members also recommend destroying the entire plant. But there
are other members that say that when they destroy just the top vegetation,
the plant comes up the next year just fine.

Other than these extreme measures, members have suggested treatment with
Daconil, Captan and acetylsalicylic acid(?) Adam Fikso: aspirin? Is this for
real? Why do you suggest aspirin?

Tom Jacobs
Poughkeepsie, NY
Zone 5-6