I have a small greenhouse devoted to tomatoes of various kinds. I have six
Dutch pots on each side for a total of twelve. I am having trouble with
mildew or fungus on the leaves.

At first the leaves start showing gray blotches that I believe is the
mildew. Then they start to shrivel and turn brown. Then I can break them off
easily where the meet main stems.

In the morning, there sometimes are water droplets on the leaves. Can that
be the problem.

I run a fan in the middle of the night to reduce humidity for about an hour.
Is that enough?

I am now running an experiment. Instead of using the regular hydroponic
drippers that I got originally, I am using four kinds. The original dripper,
1/2, 1, and 2 gph (gallon per hour) drip irrigation drippers. My routine is
off at night. During the day I irrigate with a half hour 2-1/2 hours off
during the day. This way I hope to be able to get a handle on my irrigation
schedule.

I would appreciate hearing other experiments, suggestions, and
interpretations.

I also have a General Hydroponics Power grower outdoors. In general, the
vegetation in it seems to be healthier, maybe because there is less
condensation. I also recently assembled and put on line three growers with
designs ripped off of the Power Grower. They have not been running long
enough to have much vegetation. Three more are in the works.

I am using Grow More nutrient for tomatoes as per instructions.

Bill

"Repeating Decimal" wrote in message
...
I have a small greenhouse devoted to tomatoes of various kinds. I have six
Dutch pots on each side for a total of twelve. I am having trouble with
mildew or fungus on the leaves.

It might help to know where you are, but it sounds like a humidity problem.

Why not just leave some windows/panels/the door open instead of running a
fan?

Your high-tech hydroponics+fan system seems over-engineered for the plant
care you need.

--
Brian
"Stuck down a hole, in the fog, in the middle of the night, with an owl."

On Sat, 07 Jun 2003 03:00:43 GMT, Repeating Decimal wrote
in rec.gardens.edible:

In the morning, there sometimes are water droplets on the leaves. Can that
be the problem.

Yes. Try to keep the leaves dry.

I cannot answer the rest of your questions as I do not have a green house.
--
Gardening Zones
Canada Zone 5a
United States Zone 3a
Near Ottawa, Ontario

why not spray them with some copper or dithan?
On Sat, 07 Jun 2003 03:00:43 GMT, Repeating Decimal
wrote:

I have a small greenhouse devoted to tomatoes of various kinds. I have six
Dutch pots on each side for a total of twelve. I am having trouble with
mildew or fungus on the leaves.

At first the leaves start showing gray blotches that I believe is the
mildew. Then they start to shrivel and turn brown. Then I can break them off
easily where the meet main stems.

In the morning, there sometimes are water droplets on the leaves. Can that
be the problem.

I run a fan in the middle of the night to reduce humidity for about an hour.
Is that enough?

I am now running an experiment. Instead of using the regular hydroponic
drippers that I got originally, I am using four kinds. The original dripper,
1/2, 1, and 2 gph (gallon per hour) drip irrigation drippers. My routine is
off at night. During the day I irrigate with a half hour 2-1/2 hours off
during the day. This way I hope to be able to get a handle on my irrigation
schedule.

I would appreciate hearing other experiments, suggestions, and
interpretations.

I also have a General Hydroponics Power grower outdoors. In general, the
vegetation in it seems to be healthier, maybe because there is less
condensation. I also recently assembled and put on line three growers with
designs ripped off of the Power Grower. They have not been running long
enough to have much vegetation. Three more are in the works.

I am using Grow More nutrient for tomatoes as per instructions.

Bill

in article , Brian Watson at
wrote on 6/7/03 12:30 AM:


"Repeating Decimal" wrote in message
...
I have a small greenhouse devoted to tomatoes of various kinds. I have six
Dutch pots on each side for a total of twelve. I am having trouble with
mildew or fungus on the leaves.

It might help to know where you are, but it sounds like a humidity problem.

Why not just leave some windows/panels/the door open instead of running a
fan?

Your high-tech hydroponics+fan system seems over-engineered for the plant
care you need.

--
Brian
"Stuck down a hole, in the fog, in the middle of the night, with an owl."


I am located in the Los Angeles Area near the coast. I do not want to leave
direct paths open to incoming insects. I have screening draped over the
vents. Even so, I do have ants creeping in and small white and other flies.

I am now setting growers outside the greenhouse. Although I have not
harvested tomatoes from them yet, the do not have the same mold/mildew
problems.

Bill

in article , Dave G at
wrote on 6/7/03 11:59 AM:

why not spray them with some copper or dithan?
On Sat, 07 Jun 2003 03:00:43 GMT, Repeating Decimal
wrote:

I have a small greenhouse devoted to tomatoes of various kinds. I have six
Dutch pots on each side for a total of twelve. I am having trouble with
mildew or fungus on the leaves.

I have taken a dilute copper sulfate solution and applied it to the leaves
with a cotton swab. I have not been a careful experimenter on this. There
was no improvement the few times I tried.

Bill

"Repeating Decimal" wrote in message
...
in article , Brian Watson at
wrote on 6/7/03 12:30 AM:

Why not just leave some windows/panels/the door open instead of running
a
fan?

I am located in the Los Angeles Area near the coast. I do not want to
leave
direct paths open to incoming insects. I have screening draped over the
vents. Even so, I do have ants creeping in and small white and other
flies.

I am now setting growers outside the greenhouse. Although I have not
harvested tomatoes from them yet, the do not have the same mold/mildew
problems.

Then it does seem to be a humidity problem..

What's the problem with incoming insects? Do you get a flying pest problem
where you are?

--
Brian
"Stuck down a hole, in the fog, in the middle of the night, with an owl."

in article , Brian Watson at
wrote on 6/8/03 12:30 AM:

I am now setting growers outside the greenhouse. Although I have not
harvested tomatoes from them yet, the do not have the same mold/mildew
problems.

Then it does seem to be a humidity problem..

What's the problem with incoming insects? Do you get a flying pest problem
where you are?

I guess what I do not want is an infestation of tomato or tobacco horn
worms. Nevertheless, now that you have planted that idea in my mind, that
may be a reasonable solution.

What I do not understand, is: why should that problem be so severe now when
it wasn't the previous year?

I think I will let my experiment run another week or two before opening the
door. That will give me an idea if I am watering too much or not.

Bill

in article , Repeating Decimal at
wrote on 6/8/03 12:07 PM:

in article , Brian Watson at
wrote on 6/8/03 12:30 AM:

I am now setting growers outside the greenhouse. Although I have not
harvested tomatoes from them yet, the do not have the same mold/mildew
problems.

Then it does seem to be a humidity problem..

What's the problem with incoming insects? Do you get a flying pest problem
where you are?

I guess what I do not want is an infestation of tomato or tobacco horn
worms. Nevertheless, now that you have planted that idea in my mind, that
may be a reasonable solution.

What I do not understand, is: why should that problem be so severe now when
it wasn't the previous year?

I think I will let my experiment run another week or two before opening the
door. That will give me an idea if I am watering too much or not.

Bill

Well, I have bitten the bullet. I am leaving the greenhouse door ajar by
about six inches.

Bill

In article ,
wrote:

On Sat, 07 Jun 2003 03:00:43 GMT, Repeating Decimal
wrote
in rec.gardens.edible:

In the morning, there sometimes are water droplets on the leaves. Can that
be the problem.

Yes. Try to keep the leaves dry.

I cannot answer the rest of your questions as I do not have a green house.
--
Gardening Zones
Canada Zone 5a
United States Zone 3a
Near Ottawa, Ontario

You need good air circulation to avoid the sort of problems you're having. Open
the door. Open the vents. Let the plants breathe!

If you aren't letting bugs get in to pollinate the 'maters, you'll need to
tap on the
stems once in awhile, so they'll pollinate. (I tap mine once or twice a day.)

I just ordered a book from the bookstore called "Greenhouse Gardener's
Companion."
All of the reviews raved about it. I'll report back as soon as I pick it up.

Jan

in article , Jan Flora at
wrote on 6/10/03 4:41 PM:

In article ,
wrote:

On Sat, 07 Jun 2003 03:00:43 GMT, Repeating Decimal
wrote
in rec.gardens.edible:

In the morning, there sometimes are water droplets on the leaves. Can that
be the problem.

snip

You need good air circulation to avoid the sort of problems you're having.
Open
the door. Open the vents. Let the plants breathe!

I am doing that now. For whatever reason, the problems are much worse this
year than last.

If you aren't letting bugs get in to pollinate the 'maters, you'll need to
tap on the
stems once in awhile, so they'll pollinate. (I tap mine once or twice a day.)

The first year, I did that, since then, even though I do not tap on a
regular basis, pollination does not appear to be a problem.

I just ordered a book from the bookstore called "Greenhouse Gardener's
Companion."
All of the reviews raved about it. I'll report back as soon as I pick it up.

I am looking forward to that.

Bill

On Tue, 10 Jun 2003 23:41:53 GMT, (Jan
Flora) wrote:



If you aren't letting bugs get in to pollinate the 'maters, you'll need to
tap on the
stems once in awhile, so they'll pollinate. (I tap mine once or twice a day.)


This is the right action, but for the wrong reason.

Most tomatoes are self-fertile - each flower fertilizes
itself. Insects rarely play a part in it (with the
potato-leaved tomatoes such as Brandywine and the little
currant tomatoes being exceptions - there are other
exceptions too, but they're not that common, the situation
is somewhat complex) [1].

But anyway 'most modern tomato varieties' [1] are
self-fertile, with the flowers pollinating themselves.

The reason indoor tomatoes need to be tapped or jiggled is
because the breeze isn't jiggling them around. Outdoor
tomatoes get moved enough in the breeze for the flowers to
pollinate. Some growers use fans in greenhouses for this
purpose.


I just ordered a book from the bookstore called "Greenhouse Gardener's
Companion."
All of the reviews raved about it. I'll report back as soon as I pick it up.


Please do, Jan. I'd be very interested, we're building a
hoophouse later this season.

[1] "Seed to Seed", Suzanne Ashworth, Seed Saver
Publications, Decorah, Iowa, 1991, pp. 152-153.

This is a great book for anyone who is interested in saving
seed, btw, I recommend it highly. It's useful even if
you're not planning to save seed, as it's good to know how
various plants pollinate if you are using row covers
(when/if you need to remove the row covers) or growing
indoors - do you need more than one plant? Etc.