Tomato leaves turning yellow

14 years ago

Some (10 of 25) of my tomato plants are not right. It starts out with the very newest leaves in turning yellow. I've looked at pictures of plant diseases and insect infestations from a dozen or more sites and none of them seem to apply. They are growing in hydro and the roots are white and firm, growing from the stem. A couple plants' roots seem to have a greenish cast to them but that does not seem to be the problem because others that have the same color do not have yellow leaves. There are no insects on the plants.

Other factors:

Some were planted on 10/6, others on 10/10.

All the plants are on the same aeration system, in the same size buckets.

The fertilizer levels are the same.

The pH is the same or within .2 (6.2-6.4)

They are in the same two rows and next to others.

The temps have been the same for all the plants, as is the light levels (greenhouse).

The variety of the plant does not matter. Some are plants that like cool weather, some are GH toms, some are field types.

The ppm is about the same in each bucket (~850 ppm)

Only three of the plants that were added on the above dates are unaffected. Only one (of seven) that was added more recently show any yellowing and it is hardly noticeable.

I started with eight plants on 9/24 - 9/26 and though a few of them showed some yellowing none do now.

Is it possible this is normal - the plants were started in potting mix and transplanted. Could it be they have not quite adapted yet? Or could it be explained by the wide (60 degrees) swings in temps, though in the last couple of days, I've kept the difference to about 40 degrees from the dead of night and the warmest part of the afternoon.

Any ideas? Or should I pretend they are in the garden and not check them two or three times a day?!

Mike

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Comments (8)

grizzman
14 years ago
What happens to the leaves as they age? do they stay yellow, turn green, die or what? It sounds like a deficiency but from what you've said, something else must be causing the blockade. how are your plants arranged? are they in any common proximity to each other or within your layout? (i.e. are they all clumped together in a corner or are they all perimieter plants)
Normally, I don't see tomatoes all that affected by temperature swings other than maybe stunted growth. But I suppose its possible if the temperature were to swing enough it could alter the pH enough to lock out certain nutrients.
wordwiz
Original Author
14 years ago
Grizzy,

The ones in the back row went through the same process. The edges of the leaves are now brown but otherwise they look healthy.

The buckets are lined up in rows sitting as close as I can get them to each other. I cannot see the nuits being the problem, as they use the solution from the same 35 gallon can.

Checked the back row today - they went through the same problem but they look quite healthy now, albeit with the edges of the first few leaves a bit brown. It's almost like they are going through a process of trying to adapt to a soilless environment after starting in a potting mix.

Mike
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wordwiz
Original Author
14 years ago
Grizzy,

An update:

Most of the plants are recovering and the leaves turning green again. It looks like I may lose one plant, the one closest to the heater.

Perhaps one of my initial thoughts is correct: the plants suffer a shock going from potting mix to water? Or giving them a multiple vitamin helped?

I'm still going to try about 10 plants in dirt containers, just to see how they do.

All in all, this should be a good year for gathering experience and and seeing what works best.

Mike
wordwiz
Original Author
14 years ago
Another update

I pulled five plants out of the water - they are gonzo. Some of the other 10 look like they may make it, though at least two are in the twilight zone. I did give all ten a multiple vitamin, as that really seemed to help the first batch.

Mike
paulusgnome61
14 years ago
What you have described sounds to me like the effects of pythium. Are the roots of the dead plants all dead and brown?
wordwiz
Original Author
14 years ago
Not at all. They are still white, or they were until I added them to the compost pile.

Mike
wordwiz
Original Author
14 years ago
It looks like perhaps six of them may survive. One is completely green again, the others are showing new root development.

Wish I knew what I did wrong. The first eight are growing great with five of them getting ready to bloom.

Mike
wordwiz
Original Author
14 years ago
I was wrong - one survived! A couple of others may have, they were starting to grow little roots from the stem, but I had other plants that looked far more healthy to take their place.

To my surprise, the one I kept, and it is completely yellow except for the bottom leaves, now has a bloom. Figure I might as well let it keep going and see what happens.

Mike