How can I tell if I have a fungus or water problem?

[Jlryan]

Help!
I have over 70 tomato plants (never planted on this land before). All of them have yellowing, browning branches at the bottom that eventually just dry out and break off. I'm unsure whether this could be a fungus or if it's due to periods of heavy rain and high heat. They also don't seem to have grown for the last couple weeks. I have several green tomatoes although even some (not all) of the blossoms that were once white seem to have dried up.
Thank you in advance!

[AlittleSalt]

Does the soil have at least 50% clay in it? If so, it takes a long time for it to dry.

What I'm seeing in your pictures is curled leaves - that could be many things that I'm unsure about. I know there are people here who will help you.

[Jlryan]

I'm not sure about the clay....All I know about the soil is that it had a neutral ph

[AlittleSalt]

To find out if it is clay soil, pour some water on a the ground, take a small handful of the wet soil and squeeze it into your fist - when you release your fist and the soil stays in the shape of your fist - it is heavy in clay. If the wet soil crumbles apart easily, it has more sand and/or silt in it.

[Worth1]

You should never allow the leaves to stay on a tomato plant that look like that.
It will continue to spread.
It is a result of dirt getting splashed on the leaves from heavy rain and wind born also.
At the first sign on the leaves cut them off.
The soil is fine I know it well, your typical black garden soil of the great plains that made this country what it is.
Many people think this type of soil is bad and there is nothing wrong with it.
They just need to now how too work it.
If you want clay soil come to my place, IT has red oxidized clay soil.
Blooms are going to drop in high heat there isn't much you can do about it nor will the plants grow very fast it at all.

You need to mulch around the plants.

Worth

[Jlryan]

I didn't mulch initially because I didn't think the soil was drying out like it should....I have pruned those branches immediately after the picture. I just used one of those three way soil testers and the moisture level ranges between a ten and a four depending on the area of the garden. We haven't had rain in about a week and I haven't watered and my peppers are reading a ten....They don't appear to have the leaf issues but they've not grown much at all either!

[Worth1]

Might need fertilizer.
Worth

[Nematode]

Looks like early blight.
Cant quite fell from the pics. If there are concentric rings in the lesions, that would indicate EB.
Are you using copper or daconil?

[RayR]

With the yellowing and browning starting at the leaf margins on lower leaves it looks more like drought/heat stress to me.
I don't know about moisture meters being reliable but I would just dig a hole down about 8" or so and look for myself.

[dustdevil]

It's a disease. There are plenty of tomato disease guides posted on the web. You have good topsoil in the photo. Make sure the holes in your drip hose point down. Make sure your drip hose drips and doesn't spray. If it's spraying, turn the pressure down. Tomatoes need more water when the leaves/branches start to droop.

[dustdevil]

PS: That gray when dry, black when wet is good topsoil...quite loamy. Usually when you dig down you will eventually hit yellow clay.

[Jlryan]

This is the result of my clay test! Seems like a pretty high content. When I was pulling weeds, just within a couple inches it looks like moist soil and it hasn't rained in almost a week with heat advisories every day. Not really seeing the concentric circles on the leaves, the only holes are from these dang Japanese beetles! Would the benefits of fertilizing outweigh the consequence of adding more moisture? Also I have lots of horse manure I can add!

[Gardeneer]

As Worth said, i would prune any and all the yellow leave, whether it is due to normal aging or disease. Then I would give them a good soaking fungicide spray, whether there is disease or not. And keep doing that every 7 to 10 days and after rain. Fungicide spray is a preventive measure. In early stage it may slow down the spread of disease and keep it checked. .