On Jul 7, 2:42 am, Kay Lancaster wrote:
Uproot one of them and take a look at the root system. Also dig down
and see how far the soil is actually moist. And consider the temperature...
high temps can make a plant just "stall" (it's called "heat shock" or "heat
stress").

What's the pH of the soil? How salinized might it be?

What's the temperature, day and night?

Are you sure there's not been any contamination with one of the herbicides?

Oh, and 6 hours of sun is just barely adequate for most tomato cultivars.

You might also take the dug up tomato and pot it in a 5 gallon or more
pot with commercial potting soil, and see if that improves its growth.

Kay

There are many variables that prevent tomatoes (or other plants for
that matter) from growing well.Kay hit on one theory about the PH. I
see you are from New Mexico. I believe the PH of your soil is
generally high which means alot of the nutrients aren't available to
the plants. Tomatoes need lots of sun too. It doesn't sound like you
have diseases. If the plants turn yellow it could be nematodes. One
way to know for sure is fertilize a few times. If the plants don't
respond to fertilizer, then check the roots for nodules which would be
nematodes. A couple of diseases hit tomatoes- Fusarium and
Veticillium. I'm not sure if you have that problem in New Mexico like
we have in Southern Calif. These are vascular conditions. Fusarium is
basically non-curable and plants usually die from tips back.
Verticillium is somtimes called the one-sided wilt where one branch
will die but the rest of the plant looks healthy. These are just a few
more possibilities to consider. Roundup works through translocation
which means it works through the leaves to the roots. As long as you
don't spray yout tomato plants, it won't affect them. Roundup usually
dissapates from the soil in a couple of days. Let us know what
happens. Best regards, Bob.