Ugh...here we go again?

[Jeffross1968]

Below are some lower leaves from 2 of my tomato plants. I'm worried that whatever has hit them the last 2 years has begun again. Always begins at the bottom of the plant, turns leaves yellow with brown spots, the the branch dies and literally falls off the plant and works it's way up till there is nothing left. I know that tomato plants do sometimes turn yellow on the bottom leaves but I don't think this is the case.

History: This is the 4th year I've worked this garden. It's small, only 15x12. Not a lot of room for rotating. The first year was amazing. Two years ago I got maybe 20 tomatoes from 25 plants. Last year it held off a bit longer, even though it was a very wet spring and early summer here in the mountains of WNC. This year I decided to make some changes. Firstly, I covered the garden in chicken poop and tons of dead leaves last fall, after the growing season was over. This spring, the first thing I did after planting was covering nearly every piece of exposed garden with cardboard. Since then, I've been meticulous about trimming any leaves that touch the ground. I've also for the first year begun using soaker hoses, from underneath the cardboard. And finally, no fertilizer. I stressed my plants once each of the last two years and I thought maybe I had weakened them, allowing for easier infection.

Until today, so far so good. Everything is growing awesomely. Nearly every tomato plant has tomatoes started. But went out today and found 6 or 7 stems that had begun to turn on 2 plants. If this is disease again, I'm at a loss. Can anyone help identify and maybe give me an idea of what might be done...before I write off the whole thing again before investing any more of my time? Thank you!

[Lindsaylew82]

Welcome to growing tomatoes in the south!!! Upstate (westside), SC here.

It sounds like you're doing everything right! I use neem oil as a preventative fungicide. I also use it to control squash bugs. I HAVE considered switching to a 10% milk solution though, since I'm not seeing squash bugs...( OT, but that is WILDLY bizarre). Some use baking soda spray. I've not used that.

Fungal diseases are easier to prevent than they are to treat. I spray weekly with neem from the time they are 12" up. I spray very late afternoon. Near dusk.
I also remove ANY leaves or stems that show ANY sign of disease. I carry around a small spray bottle full of rubbing alcohol. I use that to clean my scissors between cuts. Later in the season, I just take a small cup with about 2" of rubbing alcohol and dip my scissors between cuts.

Air flow is pretty important.

Where we live, they WILL eventually fall victim to fungal disease. Later succession planting can get you a fall crop. If you start seeds in pots now. Also some varieties show resistance. I've not knowingly tried them. I plant for what I like to eat and preserve.

Mulch helps as well.

[Lindsaylew82]

Oh! And crop rotating in that small of a plot is pointless for tomatoes. Having said that, I usually flop sides. Mostly tomatoes on one end and mostly cucurbits on the other. Having said that... I have junk planted everywhere by mid growing season.

[Chris_CXC]

I think I may have exactly the same issue. They yellow, brown and then the whole branch falls off.

[rainbowgardener]

At a guess, I would say early blight. Most of the common diseases of tomatoes are fungal, so the treatments are the same, fungicides. Fungicides work better as prevention than treatment. Especially if you have had fungal disease issues in the past, it helps to start using fungicide(s) from the beginning of the season and especially in wet weather. That would include Neem oil, hydrogen peroxide, baking soda solution, diluted milk. Don't mix them, but you can alternate treatments, which helps to see what your organism is most susceptible to.

[Chris_CXC]

Fantastic information. Thank you very much.

I will start with Neem oil as I have a bunch of it already.

What sort of frequency would you recommend?

Since it's a preventative, Is it worth treating these plants? Should I prune away the affected regions as well?

[applestar]

Always prune off any diseased or damaged foliage -- they only invite more fungal growth and pests are attracted to weakened plants.

If disease is suspected or foliage is infested, bag and trash, not compost.

[Lindsaylew82]

I agree that's early blight.

[Juliuskitty]

For sure, you both have early blight, I get it every year. Even if you keep leaves off the soil, it can come in on the raindrops and/or with wind. Some here are against this, but I use a half of weakest suggested strength copper fungicide spray. Copper fungicide is OMRI listed as an acceptable organic fungicide. While the purists don't like it, copper is necessary for the plant. I like it much better( personal preference) than coating my leaves in an oil that can and does cause young tomato leaves to curl, and can burn them in the bright sun even the next day.
But there are more than one way to solve most garden problems...

[suncitylinda]

Chris- Be very cautious applying Neem or any other oil in the heat we have been experiencing in SoCal. I try and ovoid oil base altogether once we break into the 90s. If you have to use it, do so in the evening, which is a problem where I live because that is when the winds pick up.

[Juliuskitty]

This link may be helpful. The pictures of the diseases are so excellent and the descriptions are exact. One of the best disease diagnosis sites I have seen.
https://www.wvu.edu/~agexten//ipm/factsh ... y_6_09.pdf

[Chris_CXC]

Thanks Linda. I have trimmed off the affected areas but held off on the Neem oil for now.

If not Neem, is there anything else you suggest that works in our region, or should I just stick with pruning?

We live on the westside, so temps aren't too bad and there is usually a cool breeze off of the ocean.

[imafan26]

You can use copper sulfate or wetable sulfur if you can find it. Do not use any sulfur product before or after an oil product or you will guarantee a burn. Sulfur is best applied in the cooler part of the day.

You can also use chlorothalanil. (sold as daconyl) it works better in conjunction with another fungicide.

The other option would be dithane : mancozeb, zaneb. It is an old fungicide but can work better because it isn't over used.

Fungal disease rears its ugly head in humid weather. A regular fungicide program when conditions are ripe is more effective than trying to fix the problem later.

Taking off the leaves and bagging and trashing will help reduce the spread. Also since this is a repeat problem, rotating to a different crop for a year or two helps cut down on the spores. It also helps to get resistant cultivars whenever possible.

https://www.growveg.com/growblogpost.aspx?id=334

[rainbowgardener]

Some of those are potent chemicals. Mancozeb is a carbamate in the same family as carbamate insecticides like Sevin.

" it helps to start using fungicide(s) from the beginning of the season and especially in wet weather. ORGANIC fungicides would include Neem oil, hydrogen peroxide, baking soda solution, diluted milk. Don't mix them but you can alternate treatments."

[feldon30]

I think I may have exactly the same issue. They yellow, brown and then the whole branch falls off.

I don't see a scrap of mulch in your garden bed or containers.

When it rains hard, and there is no mulch to disperse the water, then the rain splashes soil back onto the bottom leaves of the tomato plant. This transmits early blight, septoria, bacterial spot, bacterial speck, and anthracnose (fruit rot). Add a layer of non-dyed mulch such as pine needles, wheat straw, or pine bark.

Also important is how you water.

I water in the morning or early afternoon so that plants have a chance to dry off before going to bed. I use soaker hoses or a wand to put water right at the soil line to make sure plants are not getting wet. I only wet the leaves when applying a foliar feed such as seaweed.

[Chris_CXC]

I don't see a scrap of mulch in your garden bed or containers.

When it rains hard, and there is no mulch to disperse the water, then the rain splashes soil back onto the bottom leaves of the tomato plant. This transmits early blight, septoria, bacterial spot, bacterial speck, and anthracnose (fruit rot). Add a layer of non-dyed mulch such as pine needles, wheat straw, or pine bark.

That is correct. I was told that tomatoes didn't necessarily like mulching. I have to say, I'm thinking about adding it to these and my raised beds to hold down the water now that it is getting warmer here. The first few inches or soil are dry no matter how often I water. Below that is perfectly moist though.

BTW, I use a timed drip system for the beds and manually water the tomatoes in the pots and raised container system (although, I'm really careful not to get the foliage wet but rather give the soil below a gentle soaking). We have had absolutely no rain to speak of. The whole state has been in a real bad drought for a few years now.

[feldon30]

I was told that tomatoes didn't necessarily like mulching.

To be blunt, I would question anything said by whomever gave you this advice.

[Chris_CXC]

Fair enough. Mulch it is!