A surprise!
 

Just now I pulled up a 4" petty spurge (a frequent and several-times-daily
activity although I usually get them when they're smaller).

I noticed that on the underside of all the leaves were orange/brown slightly
raised and crowded together spots.

Any idea?

Is it transferable to other plants? I grow vegetables although the only
plants growing close to this were Easter Ledger - bistort. We don't eat
their leaves at this time of year.

Not very good pic at:

http://tinypic.com/view.php?pic=2ij4ze1&s=3

TIA

Mary

A surprise!
 

In article ,
"Mary Fisher" writes:
| Just now I pulled up a 4" petty spurge (a frequent and several-times-daily
| activity although I usually get them when they're smaller).
|
| I noticed that on the underside of all the leaves were orange/brown slightly
| raised and crowded together spots.
|
| Any idea?

Rust.

| Is it transferable to other plants? I grow vegetables although the only
| plants growing close to this were Easter Ledger - bistort. We don't eat
| their leaves at this time of year.

Yes - to pretty well everything. But don't bother about it.

There is NO point is worrying about rust transmission, as the rust
fungi are ubiquitous, and there WILL be enough spores to infect your
plants no matter what you do. And the spores travel miles.

It causes trouble only under certain weather conditions, and there
is effectively damn-all you can do about it. If you have one of the
fungicides that our Lords and Masters forbid to the public but
encourage commercial planters to use in excess (like Benlate), you
can protect a few plants. Otherwise, you can decorate those plants
with Bordeaux mixture, which will make a pretty contrast with the
rust spores. Or you can call in your local weather witch and/or
petition your favoured deity.


Regards,
Nick Maclaren.

A surprise!
 

Mary Fisher writes
Just now I pulled up a 4" petty spurge (a frequent and several-times-daily
activity although I usually get them when they're smaller).

I noticed that on the underside of all the leaves were orange/brown slightly
raised and crowded together spots.

Any idea?

Rust.

Is it transferable to other plants?

Dunno - I'm pretty sure there's more than one type of rust. I don't
know how species-specific any of them are.

--
Kay

A surprise!
 

"K" wrote in message
...
Mary Fisher writes
Just now I pulled up a 4" petty spurge (a frequent and several-times-daily
activity although I usually get them when they're smaller).

I noticed that on the underside of all the leaves were orange/brown
slightly
raised and crowded together spots.

Any idea?

Rust.

Is it transferable to other plants?

Dunno - I'm pretty sure there's more than one type of rust. I don't know
how species-specific any of them are.

Thanks, Kay. I wonder why it was only on tht plant though, there are/have
been lots of others of its ilk.

Mary
just musing ...

A surprise!
 

In message , K
writes
Mary Fisher writes
Just now I pulled up a 4" petty spurge (a frequent and several-times-daily
activity although I usually get them when they're smaller).

I noticed that on the underside of all the leaves were orange/brown slightly
raised and crowded together spots.

Any idea?

Rust.

Is it transferable to other plants?

Dunno - I'm pretty sure there's more than one type of rust. I don't
know how species-specific any of them are.


Some rusts have wide host ranges; others have narrow host ranges.

Hollyhook rust, for example, attacks a variety of mallows with various
degrees of severity. Hollyhocks, common mallow and it's near relatives,
and musk mallows are the worse sufferers. Shrubby Lavateras aren't much
affected.

Some rusts have alternate hosts - if I recall correctly one rust attacks
wheat and barberry.

I'd be surprised if a rust of Euphorbia infected other genera.
--
Stewart Robert Hinsley

A surprise!
 

In article ,
Stewart Robert Hinsley writes:
|
| Some rusts have alternate hosts - if I recall correctly one rust attacks
| wheat and barberry.

It does. Looking at Collins indicates that most have alternate hosts,
and there aren't many rusts that affect a wide range of plants. I was
wrong there.

| I'd be surprised if a rust of Euphorbia infected other genera.

Try pea rust. They are the alternate host. And, given that 'pea'
includes a fairly wide range of legumes, ....


Regards,
Nick Maclaren.

A surprise!
 

Stewart Robert Hinsley wrote:

Some rusts have wide host ranges; others have narrow host ranges.

Hollyhook rust, for example, attacks a variety of mallows with various
degrees of severity. Hollyhocks, common mallow and it's near relatives,
and musk mallows are the worse sufferers. Shrubby Lavateras aren't much
affected.

Some rusts have alternate hosts - if I recall correctly one rust attacks
wheat and barberry.

I'd be surprised if a rust of Euphorbia infected other genera.

Talking of rust, I seem to be having a major problem with it this year,
so far affecting peas (mange tout) garlic, hollyhocks and rhubarb.

Is it transferable amongst these crops/plants, and what causes it, and
is there anything I can do to prevent/treat it?

A surprise!
 

In article ,
Sandy writes:
|
| Talking of rust, I seem to be having a major problem with it this year,
| so far affecting peas (mange tout) garlic, hollyhocks and rhubarb.
|
| Is it transferable amongst these crops/plants, and what causes it, and
| is there anything I can do to prevent/treat it?

I believe not between those. You can't do much, no.


Regards,
Nick Maclaren.

A surprise!
 

In article ,
says...
Just now I pulled up a 4" petty spurge (a frequent and several-times-daily
activity although I usually get them when they're smaller).

I noticed that on the underside of all the leaves were orange/brown slightly
raised and crowded together spots.

Any idea?

Is it transferable to other plants? I grow vegetables although the only
plants growing close to this were Easter Ledger - bistort. We don't eat
their leaves at this time of year.

Not very good pic at:

http://tinypic.com/view.php?pic=2ij4ze1&s=3

TIA

Mary



It is Rust, but not to worry most rusts are plant specific and even those
that are not there is damn all you can do about them!
--
Charlie Pridham, Gardening in Cornwall
www.roselandhouse.co.uk
Holders of national collections of Clematis viticella cultivars and
Lapageria rosea

A surprise!
 

In message , Sandy
writes
Stewart Robert Hinsley wrote:
Some rusts have wide host ranges; others have narrow host ranges.
Hollyhook rust, for example, attacks a variety of mallows with
various degrees of severity. Hollyhocks, common mallow and it's near
relatives, and musk mallows are the worse sufferers. Shrubby
Lavateras aren't much affected.
Some rusts have alternate hosts - if I recall correctly one rust
attacks wheat and barberry.
I'd be surprised if a rust of Euphorbia infected other genera.

Talking of rust, I seem to be having a major problem with it this year,
so far affecting peas (mange tout) garlic, hollyhocks and rhubarb.

Is it transferable amongst these crops/plants, and what causes it, and
is there anything I can do to prevent/treat it?


I'd expect that you have four different rusts there.

Pea rust = Uromyces fabae
Garlic rust = Puccinia allii syn Puccinia porri
Hollyhock rust = Puccinia malvacearum
Rhubarb rust = Puccinia rhei-undulate
--
Stewart Robert Hinsley

A surprise!
 

In message , Nick Maclaren
writes

In article ,
Stewart Robert Hinsley writes:
|
| Some rusts have alternate hosts - if I recall correctly one rust attacks
| wheat and barberry.

It does. Looking at Collins indicates that most have alternate hosts,
and there aren't many rusts that affect a wide range of plants. I was
wrong there.

| I'd be surprised if a rust of Euphorbia infected other genera.

Try pea rust. They are the alternate host. And, given that 'pea'
includes a fairly wide range of legumes, ....

Yes. I suppose I should have caveated the possibility of an alternative
host.

Regards,
Nick Maclaren.

--
Stewart Robert Hinsley

A surprise!
 

Stewart Robert Hinsley wrote:
In message , Sandy
writes
Stewart Robert Hinsley wrote:
Some rusts have wide host ranges; others have narrow host ranges.
Hollyhook rust, for example, attacks a variety of mallows with
various degrees of severity. Hollyhocks, common mallow and it's near
relatives, and musk mallows are the worse sufferers. Shrubby
Lavateras aren't much affected.
Some rusts have alternate hosts - if I recall correctly one rust
attacks wheat and barberry.
I'd be surprised if a rust of Euphorbia infected other genera.

Talking of rust, I seem to be having a major problem with it this
year, so far affecting peas (mange tout) garlic, hollyhocks and rhubarb.

Is it transferable amongst these crops/plants, and what causes it, and
is there anything I can do to prevent/treat it?


I'd expect that you have four different rusts there.

Pea rust = Uromyces fabae
Garlic rust = Puccinia allii syn Puccinia porri
Hollyhock rust = Puccinia malvacearum
Rhubarb rust = Puccinia rhei-undulate


Thanks! Guess I've just been unlucky then!

The garlic was ready for harvesting anyway, and I'm still taking
rhubarb, so not adversely affected those, but I've had to pull up the
mange tout as it had spread to the pods and was worried about eating
them, so disappointed about that.

Would you advise I burn it rather than compost? I'd hate to spread
fungus spores to other crops if indeed it transfers this way.

A surprise!
 

In article ,
Sandy writes:
|
| Would you advise I burn it rather than compost? I'd hate to spread
| fungus spores to other crops if indeed it transfers this way.

I wouldn't. Composting will destroy the spores, as far as I know,
and they are ubiquitous, anyway. I had my broad beans wiped out
by rust one year, composted the lot, and it didn't recur. To a
first approximation, rust is caused by miasma.

Like coral spot, incidentally.


Regards,
Nick Maclaren.