I'm thinking of growing a serious quantity of watercress in my garden.

We have a small river running at the bottom of it that I plan to
utilise. I don't actually mean growing it in the river, because I'm
concerned about liver fluke infestation as it flows through sheep
pasture a short way upstream, but using the water from it.

The thing is that, despite a lot of searching, I'm not sure how liver
fluke is transmitted via watercress - ie is it taken up by the plants or
do the flukes somehow attach themselves to it? If it is the latter,
would some kind of filtering remove them?

Anyone here know about this?

On Sun, 23 Sep 2012 14:11:23 +0100, Farmer Giles wrote:

The thing is that, despite a lot of searching, I'm not sure how liver
fluke is transmitted via watercress - ie is it taken up by the plants
or do the flukes somehow attach themselves to it?

Didn't take me long, one google on Liver Fluke and the second hit
"Fasciola hepatica - Wikipedia, the free encyclopedia" told me that it's
the ingestion of uncooked contaminated food, like watercress or drinking
contaminated water. Note this is contamination with part of the flukes
life cycle rather than adult flukes,

--
Cheers
Dave.

On 23/09/2012 16:04, Chris Hogg wrote:
On Sun, 23 Sep 2012 14:11:23 +0100, Farmer Giles
wrote:

I'm thinking of growing a serious quantity of watercress in my garden.

We have a small river running at the bottom of it that I plan to
utilise. I don't actually mean growing it in the river, because I'm
concerned about liver fluke infestation as it flows through sheep
pasture a short way upstream, but using the water from it.

The thing is that, despite a lot of searching, I'm not sure how liver
fluke is transmitted via watercress - ie is it taken up by the plants or
do the flukes somehow attach themselves to it? If it is the latter,
would some kind of filtering remove them?

Anyone here know about this?

Don't think much of your searching ability!

Probably on a par with your politeness and tact.


Lots of info out there if
you google for watercress liver-fluke uk. See for example
www.torrens.org.uk/FFF/Fluke.html and many more.

Yes, I have found lots of information about the fluke, but none of it is
very clear about how the parasite passes from the plant to the person
who eats it - ie does one have to eat the flukes themselves, or their
eggs, or is it transmitted in other ways? Also, as I asked, can they be
removed by filtering?



I also read that it's illegal to grow watercress commercially in river
water, and that the water has to be of drinking quality; see
http://www.thewatercresscompany.co.uk/docs/Media_17.pdf.


I wasn't talking about growing it *in* river water - as I made quite
clear - but about using river water to grow it. It is perfectly legal to
abstract a fairly large quantity of water from streams and rivers for
horticultural purposes. As for it having to be of drinking quality, that
sounds like nonsense. What is 'drinking quality' - does that include
rainwater collected in a butt? If so, then I wouldn't like to drink it!

On Sun, 23 Sep 2012 16:36:01 +0100, Farmer Giles wrote:

Yes, I have found lots of information about the fluke, but none of it
is very clear about how the parasite passes from the plant to the
person who eats it - ie does one have to eat the flukes themselves, or
their eggs, or is it transmitted in other ways?

Read the wikpedia article I previously mentioned, it's ingestion of a
stage of the liver flukes life cycle. It has a life cycle far more
complicated than adult egg hatch into small adult grows adult.

Also, as I asked, can they be removed by filtering?

Seems a bit of moot point if growing in anything other than drinking
quality water is out lawed. Filtering, depends how big the stages (note
plural) that are likely to be in the water are. UV treatment might be an
option but IIRC watercress needs a fairly hefty running water supply.

--
Cheers
Dave.

On 23/09/2012 17:12, Chris Hogg wrote:
On Sun, 23 Sep 2012 16:36:01 +0100, Farmer Giles
wrote:

On 23/09/2012 16:04, Chris Hogg wrote:
On Sun, 23 Sep 2012 14:11:23 +0100, Farmer Giles
wrote:

I'm thinking of growing a serious quantity of watercress in my garden.

We have a small river running at the bottom of it that I plan to
utilise. I don't actually mean growing it in the river, because I'm
concerned about liver fluke infestation as it flows through sheep
pasture a short way upstream, but using the water from it.

The thing is that, despite a lot of searching, I'm not sure how liver
fluke is transmitted via watercress - ie is it taken up by the plants or
do the flukes somehow attach themselves to it? If it is the latter,
would some kind of filtering remove them?

Anyone here know about this?

Don't think much of your searching ability!

Probably on a par with your politeness and tact.


Lots of info out there if
you google for watercress liver-fluke uk. See for example
www.torrens.org.uk/FFF/Fluke.html and many more.

Yes, I have found lots of information about the fluke, but none of it is
very clear about how the parasite passes from the plant to the person
who eats it - ie does one have to eat the flukes themselves, or their
eggs, or is it transmitted in other ways? Also, as I asked, can they be
removed by filtering?

From my first link:

"The adult fluke lays its eggs which pass out in the hosts faeces and
hatch into a larval form (miracidia) which, if the faeces are
deposited in water, swim around and infect water snails (mainly
lymnaea truncatula but probably other species as well). Having
infected the snail, the larva develops until it is ready for the next
stage of its life when it develops into multiple cercaria which leave
the snail host and attach themselves to plants growing in the water
such as grass or watercress, where they encyst.

The life cycle is completed when the grass (or other plant material)
is eaten. The encysted cercariae come to life in the gut, migrate
through the gut wall and travel to the liver where the adult fluke
develops."

What more do you want?

Oh dear, how many times do I have to say that I don't intend to grow it
*in* the water! I wanted to know (but please don't 'trouble' yourself to
attempt another 'reply'!) that can whatever it is that transmits the
parasite be filtered out.




I also read that it's illegal to grow watercress commercially in river
water, and that the water has to be of drinking quality; see
http://www.thewatercresscompany.co.uk/docs/Media_17.pdf.


I wasn't talking about growing it *in* river water - as I made quite
clear - but about using river water to grow it. It is perfectly legal to
abstract a fairly large quantity of water from streams and rivers for
horticultural purposes. As for it having to be of drinking quality, that
sounds like nonsense. What is 'drinking quality' - does that include
rainwater collected in a butt? If so, then I wouldn't like to drink it!

There are legal standards for the quality of drinking water. Google
for drinking water standards uk.


There may be, but most sources of water in which watercress is grown
commercially would not meet them.

Anyway, and leaving that side, why do some people respond to questions
on usenet as if the questioner has knocked on their door at 2.00am
demanding immediate assistance? If you don't know the answer, or find
the question too stupid for words, why bother to attempt a reply?

I've been posting on usenet for many years, but recently I've stopped
posting to all newsgroups - except this one, and I'll do that when I've
finished writing this bit - because they all seemed to have become
populated either with nutters or with those who appear to be in a
permanent bad mood.

Cheerio.

On Sun, 23 Sep 2012 18:47:27 +0100, Farmer Giles wrote:

Oh dear, how many times do I have to say that I don't intend to grow it
*in* the water!

I'm not sure how you propose to grow watercress without it being in the
water. It's an aquatic/semi aquatic plant...

--
Cheers
Dave.

On 23/09/2012 19:39, Dave Liquorice wrote:
On Sun, 23 Sep 2012 18:47:27 +0100, Farmer Giles wrote:

Oh dear, how many times do I have to say that I don't intend to grow it
*in* the water!

I'm not sure how you propose to grow watercress without it being in the
water. It's an aquatic/semi aquatic plant...

It is quite possible to grow watercress in trays if they are kept damp
with misting

On Sun, 23 Sep 2012 19:56:27 +0100, David Hill wrote:

Oh dear, how many times do I have to say that I don't intend to grow
it *in* the water!

I'm not sure how you propose to grow watercress without it being in
the water. It's an aquatic/semi aquatic plant...

It is quite possible to grow watercress in trays if they are kept damp
with misting

And where is this misting water coming from?

--
Cheers
Dave.

In article , says...

I'm thinking of growing a serious quantity of watercress in my garden.

We have a small river running at the bottom of it that I plan to
utilise. I don't actually mean growing it in the river, because I'm
concerned about liver fluke infestation as it flows through sheep
pasture a short way upstream, but using the water from it.

The thing is that, despite a lot of searching, I'm not sure how liver
fluke is transmitted via watercress - ie is it taken up by the plants or
do the flukes somehow attach themselves to it? If it is the latter,
would some kind of filtering remove them?

Anyone here know about this?


http://www.patient.co.uk/doctor/Fasciola-Hepatica.htm

quote

" Life cycle

Immature eggs are discharged in the biliary ducts and in the stool. The eggs release
miracidia, which invade a suitable snail intermediate host.
In the snail the parasites develop into cercariae, which are released from the snail and
encyst as metacercariae on aquatic vegetation or other surfaces.
Mammals become infected by eating contaminated vegetation. Humans become infected by
ingesting contaminated freshwater plants, especially watercress.
After ingestion, the metacercariae encyst in the duodenum and migrate through the
intestinal wall, the peritoneal cavity, and the liver parenchyma into the biliary ducts,
where they develop into adults. The adult flukes live in the large biliary ducts of the
mammalian host.
Human infection by consumption of raw liver from infected sheep, goats, and cows has also
been reported."

Liverfluke in farm livestock is on the increase in UK.

In UK it should only be grown in potable water ( drinking standard, not, untreated
river/garden water). If someone unwell is planning to consume a serious quantity of raw cress
for health reasons, it might be unwise to increase the risk of other zoonotic health problems
such as e coli and campylobacter.

AIUI zoonoses are not the only risk to human health from eating raw watercress .New Zealand
(where maori eat a LOT of cress) is currently concerned about the levels of bacteria, metals
and pesticides being taken up by watercress, in the land-runoff that enters rivers.

http://www.ncbi.nlm.nih.gov/pubmed/15108742


Janet.

On Sun, 23 Sep 2012 19:39:52 +0100 (BST), "Dave Liquorice"
wrote:

On Sun, 23 Sep 2012 18:47:27 +0100, Farmer Giles wrote:

Oh dear, how many times do I have to say that I don't intend to grow it
*in* the water!

I'm not sure how you propose to grow watercress without it being in the
water. It's an aquatic/semi aquatic plant...

On the latest GQT Bunny Guinness says she grows watercress in her
greenhouse and in her garden. ~Watercress is traditionally grown in
running water but it is obviously possible to grow it in soil kept
wet.
Anyone tried it? Any advice out there?

Pam in Bristol

On 23/09/2012 18:47, Farmer Giles wrote:



I've been posting on usenet for many years, but recently I've stopped
posting to all newsgroups - except this one, and I'll do that when I've
finished writing this bit - because they all seemed to have become
populated either with nutters or with those who appear to be in a
permanent bad mood.


Haven't some people developed remarkably thin skins?

In article , says...
I don't think he actually wants to know. He seems determined to use
his polluted stream water in some way (although how isn't clear), and
seems only interested in filtering out the liver fluke, regardless of
the fact that there would be a lot more to cleaning up water for
watercress production than that. Quite what he means by "a serious
quantity of watercress" isn't clear either, although I can't see that
it would be exclusively for his own use, and unless he's just giving
it away he's presumably going to sell it, in which case he comes under
the purview of the law. He also thinks that many commercial producers
use water that wouldn't meet the standards of drinkable water, which
suggest he doesn't actually know much about it or hasn't done much
research on the matter, despite his claim.


Well, that outlook is depressingly familiar on usenet (and urg) these days. Next comes
an angry objection to "uninvited strangers posting in my thread" :-)

Never mind.It's interesting for others to see new information and either learn a litle
more from it or use it as a jumping off point for further reading and discussion.



Janet.

On Sep 24, 9:05*am, Pam Moore wrote:
On Sun, 23 Sep 2012 19:39:52 +0100 (BST), "Dave Liquorice"

wrote:
On Sun, 23 Sep 2012 18:47:27 +0100, Farmer Giles wrote:

Oh dear, how many times do I have to say that I don't intend to grow it
*in* the water!

I'm not sure how you propose to grow watercress without it being in the
water. It's an aquatic/semi aquatic plant...

On the latest GQT Bunny Guinness says she grows watercress in her
greenhouse and in her garden. *~Watercress is traditionally grown in
running water but it is obviously possible to grow it in soil kept
wet.
Anyone tried it? Any advice out there?

Pam in Bristol

I grow it in a pot that sits in a washing up bowl and make sure the
water is kept topped up in the bowl.

Jonathan

It's a wild plant in the UK, and grows not just in water but on the muddy edges of streams.

The idea of growing it in running water is that running water is less likely to have the snails who are the intermediate host.

Using "water from the river" as the OP suggests is, in infection terms, the same as growing it in the river, so what he needs to do is filter his water to bring it up to standards of quality suitable for growing watercress - ie not just filter out the relevant life stage of the fluke, but also any bacterial nasties that are in there.

On 24/09/2012 09:05, Pam Moore wrote:
On Sun, 23 Sep 2012 19:39:52 +0100 (BST), "Dave Liquorice"
wrote:

On Sun, 23 Sep 2012 18:47:27 +0100, Farmer Giles wrote:

Oh dear, how many times do I have to say that I don't intend to grow it
*in* the water!

I'm not sure how you propose to grow watercress without it being in the
water. It's an aquatic/semi aquatic plant...

On the latest GQT Bunny Guinness says she grows watercress in her
greenhouse and in her garden. ~Watercress is traditionally grown in
running water but it is obviously possible to grow it in soil kept
wet.
Anyone tried it? Any advice out there?

Pam in Bristol


One of the reasons for commercial cress beds being in running water is
for frost protection, when frost is around the water level is raised and
the cress is pressed down so that it is under water so kept from frosting.
It will grow well without the running water, though as I have said
before I would rather grow Land Cress.
David @ the damp end of Swansea Bay