Charlie,

I see that you just registered yesterday. Welcome to the forum.

Can you give us more details on your plants and your growing conditions. I understand you are in a greenhouse but more details are needed - temps, humidity, watering, etc.

Also, more pics of the affected plants would be very helpful in trying to help you.

Gary

Hi Gary,

Thanks for the welcome.

I've linked below to images of the plants, both in the greenhouse & after being pulled, also a photo from May as reference.

When we first noticed a problem our temps were averaging between 75-90, though we had the high heat last week topping out at 110 with the exhaust fans running - the plants were dying well before this however.

Watering is done via drip irrigation for a few hours a day depending upon heat & sunshine, I just spoke to the greenhouse mgr & there is no method other than feeling the soil humidity with a finger. The beds are raised & his theory is that excess water drains out the bottom, I disagree with this & am ordering a humidity probe. Same problem with greenhouse humidity, there is no sensor in place.

I hope the pics help because I'm realizing we don't have enough data on the water/humidity-

Charlie

Here is a link that might be useful: photos on web at photobucket

I found our temp & air humidity, reading 100F and 55% humidity currently.

Charlie

Well, I'm not seeing any adventitious roots in the dying stems, but otherwise it could be tomato pith necrosis. The hollow stems are typical. ACES suggests that it's something that plants can grow out of, brought on by high nitrogen levels, but I'm not seeing a general consensus on environmental factors. You can hunt around a bit yourself and see what you find that may apply to your case.

That's the likeliest thing I can find... Fusarium, sting nematodes, russet mites, and nutrient deficiencies don't decay the pith; bacterial canker usually has decayed spots all along the stem, and can put spots on the fruit; and phytopthora root rot (not late blight) is uncommon unless the soil is waterlogged.

It's definitely a systemic disease, which points to a soilborne fungus or bacteria. Soilborne ones can be very difficult to get rid of unless you can replace the soil entirely... I wish you luck.

--Alison

Charlie,

I think Alison has you on the right track. I am definitely not the disease expert. Hopefully, your outside testing facilities will give you some answers.

My comments are about the heat and humidity. They are way to high for healthy maters. I assume that you are using shade cloths but maybe not. Also, finding a way to open up your greenhouse would help.

Do you currently sterilize the dirt in your raised beds? Something to definitely consider if you don't.

I think I understand why you so severely prune your plants (access to pick fruit) but the pruning seems to be extreme and is probably detrimental to plant health.

Lots of other questions but I need to do some work today.

Good luck,

Gary

Thank you Gary & Alison for your help - I will post the results when I get them. I do know that our nitrogen levels are high, I am going to look for solutions.

Gary, the soil hasn't been sterilized, is it possible to do so without removing it from the beds? Do either of you have any suggested reading/equipment for setting up better environmental control? I am going to do some searching onsite & internet.

Again, thank you very much for the direction-

Charlie

Charlie,

I don't know of a way to sterilize in the bed. Sorry.

We always removed the dirt and baked or steamed our dirt. Helps immensely in the battle against disease and weeds. Very labor intensive but for us it was a family operation.

Good luck and keep us updated on what you find out.

Might mention that there is a greenhouse forum on this site. Lots of growers visit it.

Don't be a stranger to this forum. Lots of good people and lots of good info.

Gary

Gary,

I intend to visit often & would have been earlier if I knew about the site. I just posted to the greenhouse forum, post is entitled "Greenhouse Reset", asking about sterilization & some other questions dealing with making our house better if you want to follow it.

I'll post here when we get our lab results back, it should be before Weds.

Charlie

Hi All,

So far testing indicates:
we don't have a nematode problem,
no fusarium or verticillium present (preliminary result)

I spoke with a plant pathologist at Cornell who is doing the diagnostic work & she said that it probably was not tomato pith necrosis - but she had found mites, the result from Cornell's entomology was that there were eriophyid mites on the sample, "most likely" tomato russet mites.

I'll let everyone know when the final results are in-

Charlie