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Mon Apr 2 15:07:21 CEST 2007

hardy Aroids)" <ARISAEMA-L at NIC.SURFNET.NL> Aroids)" <ARISAEMA-L at NIC.SURFNET.NL>
Sender: "Arisaema Enthusiast Group (AEG) Discussion List (and other=
From: "George R. Stilwell, Jr." <GRSJr at WORLDNET.ATT.NET>
Subject: Re: Decapitated Arisaema/rust
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Giorgio,

Several of the members have tried the decapitating method on plants with
the rust. It's been some years, so I don't remember the details or who th=ey
were.

I respect your more recent understanding, but we're really discussing a
non-diseased plant that's been decapitated and will it live. My
understanding is that it will.

On the other hand, your understanding of the rust says don't expect
decapitation to be a cure.

Ray

At 4/2/2007, you wrote:
>Il giorno 31/mar/07, alle ore 22:16, George R. Stilwell, Jr. ha scritto:
>
> > Russell,
> >
> > The recommended treatment for Arisaema with the rust is to
> > decapitate them, burn the leaves, and plant the tuber. It works fine.
> >
> > Just plant your tuber and wait.
> >
> > Ray
>
>Ray,
>
>I thought it was mandatory to destroy the whole plant....
>
>Giorgio
>
>from the site :
>
>http://www.shieldsgardens.com/amaryllids/Arisaema.html
>
>There seems to be one major pest that afflicts Arisaema, the Arisaema
>Rust, Uromyces ari-triphylli. The currently recommended treatment for
>Arisaema Rust is total destruction of all the afflicted plants in a
>collection, according to some in the Arisaema Enthusiasts Group.
>
>A forest perennial, Jack-in-the-Pulpit, Arisaema triphyllum,
>reproduces both asexually and sexually, as either a male or a female.
>Each individual possesses the ability to change gender multiple times
>throughout its lifetime. Gender is correlated with size: Small plants
>do not flower and reproduce clonally only, medium sized plants are
>males, and large plants are females. Size and gender for a given
>growing season are predetermined by the amount of photosynthate
>stored over the previous growing season in an underground corm.
>Infection by the systemic rust, Uromyces ari-triphylli, has the
>potential to alter this reproductive strategy by affecting the size,
>gender and persistence of infected plants. Disease is transmitted
>horizontally and to clonal offspring, but not vertically to sexually
>produced offspring. Although sexual reproduction is costly for an
>already diseased-stressed plant, seed derived offspring are more fit
>because they escape disease. The other reproduction option,asexual,is
>not advantageous since offspring will be diseased. As part of an
>ongoing demographic study investigating the effects of infection on
>both individuals and populations, we censused six natural populations
>of Jack-in-the-Pulpit, three healthy and three diseased. Preliminary
>results revealed infected flowering individuals were smaller than
>their healthy counterparts and diseased individuals were more likely
>to flower than healthy individuals of the same size. In addition,
>diseased populations had a higher proportion of flowering individuals
>than healthy populations. These data suggest that disease may cause a
>plant to invest in sexual reproduction and to do so at a smaller size
>than healthy individuals.

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Giorgio, 
Several of the members have tried the decapitating method on plants with
the rust. It's been some years, so I don't remember the details or who
they were. 
I respect your more recent understanding, but we're really discussing a
non-diseased plant that's been decapitated and will it live. My
understanding is that it will. 
On the other hand, your understanding of the rust says don't expect
decapitation to be a cure. 
Ray 
 
At 4/2/2007, you wrote: 
<blockquote type=cite class=cite cite>Il giorno 31/mar/07, alle ore
22:16, George R. Stilwell, Jr. ha scritto: 
&gt; Russell, 
&gt; 
&gt; The recommended treatment for Arisaema with the rust is to&nbsp;
 
&gt; decapitate them, burn the leaves, and plant the tuber. It works
fine. 
&gt; 
&gt; Just plant your tuber and wait. 
&gt; 
&gt; Ray 
Ray, 
I thought it was mandatory to destroy the whole plant.... 
Giorgio 
from the site : 
<a href="http://www.shieldsgardens.com/amaryllids/Arisaema.html" eudora=="autourl">http://www.shieldsgardens.com/amaryllids/Arisaema.html</a><b=r> 
There seems to be one major pest that afflicts Arisaema, the
Arisaema&nbsp; 
Rust, Uromyces ari-triphylli. The currently recommended treatment
for&nbsp; 
Arisaema Rust is total destruction of all the afflicted plants in a&nbsp;
 
collection, according to some in the Arisaema Enthusiasts
Group. 
A forest perennial, Jack-in-the-Pulpit, Arisaema triphyllum,&nbsp; 
reproduces both asexually and sexually, as either a male or a
female.&nbsp; 
Each individual possesses the ability to change gender multiple
times&nbsp; 
throughout its lifetime. Gender is correlated with size: Small
plants&nbsp; 
do not flower and reproduce clonally only, medium sized plants are&nbsp;
 
males, and large plants are females. Size and gender for a given&nbsp;
 
growing season are predetermined by the amount of photosynthate&nbsp;
 
stored over the previous growing season in an underground corm.&nbsp;
 
Infection by the systemic rust, Uromyces ari-triphylli, has the&nbsp;
 
potential to alter this reproductive strategy by affecting the
size,&nbsp; 
gender and persistence of infected plants. Disease is transmitted&nbsp;
 
horizontally and to clonal offspring, but not vertically to
sexually&nbsp; 
produced offspring. Although sexual reproduction is costly for an&nbsp;
 
already diseased-stressed plant, seed derived offspring are more
fit&nbsp; 
because they escape disease. The other reproduction
option,asexual,is&nbsp; 
not advantageous since offspring will be diseased. As part of an&nbsp;
 
ongoing demographic study investigating the effects of infection on&nbsp;
 
both individuals and populations, we censused six natural
populations&nbsp; 
of Jack-in-the-Pulpit, three healthy and three diseased.
Preliminary&nbsp; 
results revealed infected flowering individuals were smaller than&nbsp;
 
their healthy counterparts and diseased individuals were more
likely&nbsp; 
to flower than healthy individuals of the same size. In addition,&nbsp;
 
diseased populations had a higher proportion of flowering
individuals&nbsp; 
than healthy populations. These data suggest that disease may cause
a&nbsp; 
plant to invest in sexual reproduction and to do so at a smaller
size&nbsp; 
than healthy individuals.</blockquote></body>
 
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