Yellowing/Browning Roma Plant

[Zaxsta]

Well, I have this Roma tomato plant and its starting to yellow/brown. There are a bunch of tiny little discolored spots on the leaves (not concentric circles, though). The surface of the leaves seems rough in general. New growth is stunted/drying out.





I know that last one isn't that great, but if you look towards to top you can see the shriveling of new growth. Additionally, you can get a feel for the browning/spots I am talking about. Help! What does it have? What can I do?

[The Helpful Gardener]

Pretty hard to say from the photos, but growing tips going fast like that kind of rules out early blight (which usually starts low and works up). I am not sure but suspect late blight might well be your issue; it certainly looks and sounds fungal, and this can be a worst case scenario. I suspect you are not out much dough on a plant this size and might even consider a new start, but if that's not an option you have a few others.

I'd first try a mild H2O2 treatment; four ounces of 3% hydrogen peroxide mixed with a gallon of water and spray top to bottom, saturating everything. This is a good antimicrobal for fungus or bacterial, so in the off chance it is a bacerial leaf spot we have covered that angle as well.

Now that we have decreased the biology in the phyllosphere (fancy talk for killing all the critters and mushrooms on the leaf), we need to put some back. Just like any ecosystem on Earth, healthy biodiversity is the key to not letting any one species dominate the system (like some nasty blight on your maters). We can put it back a lot of ways but milk does this easily, cheaply, and I know what the answer is for most folks if I ask "got milk?"

10:1 is a good preventative mix but I go 3:1 water to milk for existing disease, spray to saturation, and repeat. Millk has some amazing chemical propertiesof its own (goats milk too), as well as being a preferred growing habitat for Lactobacillus, the world's most common and useful bacteria (we use it not just a a composter, but as the catalyst for sour cream, cheese, yogurt, kefir, kim chee, saurkraut, pickles, sourdough bread, Belgium lamberts (mmm, Belgian lamberts... ). It is a discriminate and mostly benign, even beneficial decomposer, as it seems to be antifungal in it's own right. Heck, milk is how we get antifungal

Fish hydrolysate (a purified emulsion) is another good way to stimulate biologies; the day after I did the milk I might follow up with this. As directed on the bottle, this is a good bacterial food and a good fungal food but we have already tipped the scales to bacterial with the milk spray and the nitrogen in the fish spikes growth in our Lactobacillus even further. Our leaf is now again protected from further infection by a film of antifungal milk populated by antifungal bacteria. Take that fungus.

Or you can go chemical and kill all the help I was creating above with a fungicide. It will likely have a higher intitial kill than H2O2/Lactobacillus, but it leaves a vacuum behind it. The first thing to crawl from the wreckage won't be a good guy, and likely be the bad guy you were after. Let's treat the disease (lack of biology to counteract the fungus) and not the symptom (dang fungus).

HG

[garden5]

Could it be septoria? Septoria is very similar to the early blight. I'm not sure how good HG's method would work for septoria, but it's worth a try.

Here is a comparison of different tomatoes diseases.

[gixxerific]

Long an involved response there HG but I like it, I like it a lot.

[Zaxsta]

Thanks, I'll give it a try (hydrogen peroxide/milk). Surprising that the microbes in milk are beneficial for tomatoes.

[The Helpful Gardener]

Way, And the calcium is good for blossom end rot...

Hydrogen peroxide works for bacterial spotting as well, and bacterial counter culture doesn't care who its crowding out...

HG

[gixxerific]

Question on the milk HG. I have heard that store bought milk was not that good to use. Due to pasteurization killing all the bacteria. I would think that straight from the cow milk or even yogurt would possible have a better chance to be anti-fungal

Comments?

[rainbowgardener]

When I was using the milk treatment on my tomatoes last summer, I put a tablespoon or so of active culture yoghurt in the milk solution and let it sit at room temperature for a few hours. Don't know if it was really necessary, but I had the same reasoning. The treatment worked great, but maybe it would have without the yoghurt too.

There's that lack of control groups thing again! If I had some acreage, I would try using control groups some times. But with one raised bed of tomato plants, I'm going to give them all whatever I think is the best shot and too bad about the data lost!

[applestar]

When I was out of milk, I used "whey" (clear liquid pooling in yogurt, cottage cheese, sour cream). There's also saurkraut and lactofermented pickle juice...

IMHO, fresh milk smells best in the spray though.

Note that you need to wash the sprayer thoroughly after using the milk spray if you're also going to use the same sprayer for ACT or AACT.

Hey HG, do you think we could also use hooch off the sourdough starter, or is that another organism altogether? It's yeast waste... some alcohol you said. Any live yeast that would out-compete? Would the substance cause more problems than it's worth?

[The Helpful Gardener]

The hooch has a lot of alcohol, so kind of counter-productive... (the last batch of bread was good though; I am almost dialed in with my starter and recipe. Still a few more tweaks...)

Culturing is certainly not a bad idea, but we are talking about the most common bacteria around. Ever leave the milk out and NOT have it spoil? These guys WILL show up if you leave their favorite food around on leaves and stems and other easy-to-find locations... besides when YOU do it you are normally getting a monocultural food strain; when Nature does, she tends to open the doors to all comers... certain food strains are better; L. caseii seems to be a particularly beneficial species, and some like Stonyfield use multiple strains. Anything "probiotic" usually has multiples including L. caseii...

Mix your pickle juice with your sour dough and sour cream and kefir, and your probiotic yogurt, and NOW you're cooking...

HG