Evening,

I think that this topic was covered about a month ago on this group but I
can't find it on my system - so apologies for repeating the question.

My tomatoes are still growing/ripening etc, however the leaves on the plants
are covered with little white flies - little negatives of black flies!

What are they, what do they do and should I do something about them next
year or leave them alone?

Thanks for the help.

Cheers,


Andrew

In article , ajr
writes
Evening,

I think that this topic was covered about a month ago on this group but I
can't find it on my system - so apologies for repeating the question.

My tomatoes are still growing/ripening etc, however the leaves on the plants
are covered with little white flies - little negatives of black flies!

What are they, what do they do and should I do something about them next
year or leave them alone?

Assuming that the tomatoes are growing in a greenhouse, it would be well
to tackle them now while they are active or they will hibernate over
winter to re-breed and become an annual nuisance to all your crops. They
are there because they like the conditions, so you will need to make
things less pleasant for them, while at the same time not harming your
plants or their crops.

We use an infusion of nettles in water for that job because it is an
organic insect repellent rather than a chemical pesticide which can
leave unwanted residues on the tomatoes. We apply it to the leaves of
the plants and within a day or so, all the white flies are gone. Any
remaining nettle infusion is then ingested through the leaves into the
plants to act as an organic plant tonic and feed.

Nettle infusion can be prepared by soaking young leaves in water for
7-10 days, by which time they will have biodegraded. The infusion has a
characteristic odour, but it is not long lasting and is one of the
reasons for its effectiveness. Full details can be read in the urg FAQ
on the subject at: http://www.nugget.demon.co.uk/MetaFAQ/nettle.html
--
Alan & Joan Gould - North Lincs.

"Alan Gould" wrote in message
...
In article , ajr

[snip]

Any
remaining nettle infusion is then ingested through the leaves into the
plants to act as an organic plant tonic and feed.

Rubbish. Plants do not have stomachs and cannot digest organic matter. It
is also a moot point whether organic molecules, which tend to be rather
large objects, can penetrate through the surface of the leaves into the
interior of the plant.

[snip]

Franz Heymann

On Sat, 18 Oct 2003 08:48:01 +0000 (UTC), "Franz Heymann"
wrote:


"Alan Gould" wrote in message
...
In article , ajr

[snip]

Any
remaining nettle infusion is then ingested through the leaves into the
plants to act as an organic plant tonic and feed.

Rubbish. Plants do not have stomachs and cannot digest organic matter. It
is also a moot point whether organic molecules, which tend to be rather
large objects, can penetrate through the surface of the leaves into the
interior of the plant.

[snip]

Franz Heymann


spoil sport :-)
--
Martin

In article , Franz Heymann notfranz.
writes
Plants do not have stomachs and cannot digest organic matter. It
is also a moot point whether organic molecules, which tend to be rather
large objects, can penetrate through the surface of the leaves into the
interior of the plant.

Plants do not have stomachs, but they process dissolved nutrients into a
growing medium, both through their leaves and through their roots. They
also process light into plant food by photosynthesis.
--
Alan & Joan Gould - North Lincs.

in article , Alan Gould at
wrote on 18/10/03 11:54 am:

In article , Franz Heymann notfranz.
writes
Plants do not have stomachs and cannot digest organic matter. It
is also a moot point whether organic molecules, which tend to be rather
large objects, can penetrate through the surface of the leaves into the
interior of the plant.

Plants do not have stomachs, but they process dissolved nutrients into a
growing medium, both through their leaves and through their roots. They
also process light into plant food by photosynthesis.

I must say, I was a bit surprised at Franz's reply. Surely he's heard of
foliar feeds?
--

Sacha
(remove the 'x' to email me)

"Alan Gould" wrote in message
...
In article , Franz Heymann notfranz.
writes
Plants do not have stomachs and cannot digest organic matter. It
is also a moot point whether organic molecules, which tend to be rather
large objects, can penetrate through the surface of the leaves into the
interior of the plant.

Plants do not have stomachs, but they process dissolved nutrients into a
growing medium, both through their leaves and through their roots. They
also process light into plant food by photosynthesis.

I believe that I am correct in saying that plants make use of only inorganic
compounds as nutrients.
If anybody has actual evidence to prove me wrong, I will of course
apologise.

Franz

In article ,
(Sacha) wrote:

Surely he's heard of foliar feeds?

Probably. He may believe that they only work for small molecules such as
potassium/magnesium/ammonium sulphate.


Steve Harris - Cheltenham - Real address steve AT netservs DOT com

"Sacha" wrote in message
...
in article , Alan Gould at
wrote on 18/10/03 11:54 am:

In article , Franz Heymann notfranz.
writes
Plants do not have stomachs and cannot digest organic matter. It
is also a moot point whether organic molecules, which tend to be rather
large objects, can penetrate through the surface of the leaves into the
interior of the plant.

Plants do not have stomachs, but they process dissolved nutrients into a
growing medium, both through their leaves and through their roots. They
also process light into plant food by photosynthesis.

I must say, I was a bit surprised at Franz's reply. Surely he's heard of
foliar feeds?

Of course I have. I use them regularly. They consist of inorganic
compounds. Alan implied that plants could assimilate an infusion of
nettles, which is likely to be largely organic in its contents.

Franz Heymann

"Franz Heymann" wrote in message
...

"Sacha" wrote in message
...
in article , Alan Gould at
wrote on 18/10/03 11:54 am:

In article , Franz Heymann
notfranz.
writes
Plants do not have stomachs and cannot digest organic matter. It
is also a moot point whether organic molecules, which tend to be
rather
large objects, can penetrate through the surface of the leaves into
the
interior of the plant.

Plants do not have stomachs, but they process dissolved nutrients into
a
growing medium, both through their leaves and through their roots.
They
also process light into plant food by photosynthesis.

I must say, I was a bit surprised at Franz's reply. Surely he's heard
of
foliar feeds?

Of course I have. I use them regularly. They consist of inorganic
compounds. Alan implied that plants could assimilate an infusion of
nettles, which is likely to be largely organic in its contents.

After a wee bit of reading to refresh my ailing memory, I have to say that
apparently plants can also absorb growth hormones through their leaves.

Franz

"Franz Heymann" wrote in message
...

"Alan Gould" wrote in message
...
In article , Franz Heymann notfranz.
writes
Plants do not have stomachs and cannot digest organic matter. It
is also a moot point whether organic molecules, which tend to be rather
large objects, can penetrate through the surface of the leaves into the
interior of the plant.

Plants do not have stomachs, but they process dissolved nutrients into a
growing medium, both through their leaves and through their roots. They
also process light into plant food by photosynthesis.

I believe that I am correct in saying that plants make use of only
inorganic
compounds as nutrients.
If anybody has actual evidence to prove me wrong, I will of course
apologise.

In another post I ghave acknowledged that plants can also absorb growth
hormones through their leaves.

Franz

In article , Franz Heymann notfranz.
writes

I believe that I am correct in saying that plants make use of only inorganic
compounds as nutrients.
If anybody has actual evidence to prove me wrong, I will of course
apologise.

That would be inappropriate in the context of your definition of
organic. My reference is to the gardening sense of the word.
--
Alan & Joan Gould - North Lincs.

The message
from Sacha contains these words:


I must say, I was a bit surprised at Franz's reply. Surely he's heard of
foliar feeds?

Or commercial systemic pesticides or weedkillers, also applied to
foliage and absorbed through it.

Janet.

"Franz Heymann"
wrote in message
...

"Alan Gould" wrote
in message
...
In article
, Franz Heymann
notfranz.
writes
Plants do not have stomachs and cannot
digest organic matter. It
is also a moot point whether organic
molecules, which tend to be rather
large objects, can penetrate through the
surface of the leaves into the
interior of the plant.

Plants do not have stomachs, but they process
dissolved nutrients into a
growing medium, both through their leaves and
through their roots. They
also process light into plant food by
photosynthesis.

I believe that I am correct in saying that
plants make use of only inorganic
compounds as nutrients.
If anybody has actual evidence to prove me
wrong, I will of course
apologise.

I'd like to tell you about a little experiment I
conducted last year. I'd noticed that Teasel
plants in my garden were collecting water in the
base of the leaves and flies and other insects
were becoming trapped in the water. I wondered if
they were getting any nutriment from this.

So, I made holes in all of the leaves in some
plants to drain the water, these plants became
quite sickly compared with those I left alone.
Now the bit I'm not sure about, but here goes,
shoot me down, tell me the correct answer,
whatever. Anyway, I'm pretty sure drowned, rotting
insects produce mostly organic compounds, so I
assume that the Teasels are using those; and maybe
they are a special case, on their way to becoming
a "carniverous" plant, but to me it looks as
though Teasels do use organic compounds as
nutrients.

This year I'm mainly trying to get rid of the
b****y things.

In article , AliCat
writes
I'd like to tell you about a little experiment I
conducted last year. I'd noticed that Teasel
plants in my garden were collecting water in the
base of the leaves and flies and other insects
were becoming trapped in the water. I wondered if
they were getting any nutriment from this.

So, I made holes in all of the leaves in some
plants to drain the water, these plants became
quite sickly compared with those I left alone.
Now the bit I'm not sure about, but here goes,
shoot me down, tell me the correct answer,
whatever. Anyway, I'm pretty sure drowned, rotting
insects produce mostly organic compounds, so I
assume that the Teasels are using those; and maybe
they are a special case, on their way to becoming
a "carniverous" plant, but to me it looks as
though Teasels do use organic compounds as
nutrients.

This year I'm mainly trying to get rid of the
b****y things.


You are quite right to assume that decaying animal or plant material
becomes nutrients useable by plants. Not all are suitable for any plant
though and not all decaying material would readily be chosen as plant
feed by gardeners practising organic systems.

A very useful and interesting work of reference dealing with many of the
ways in which plants evolve, propagate, acquire their food, how they
relate to other plants, animals and their environments is 'The Private
Life of Plants' - a natural history of plant behaviour by David
Attenborough. Pub. 1995 by BBC books ISBN 0563 37023 8

Principles of organic gardening are described in an urg FAQ at:
http://www.nugget.demon.co.uk/MetaFA...gardening.html
--
Alan & Joan Gould - North Lincs.