Is this late blight?

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bower
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Is this late blight?

#1

Post: # 50868Unread post bower
Tue Jul 20, 2021 9:00 pm

Very humid weather here the past week. Today I kept seeing these issues cropping up. Mainly on new sucker growth, the little stem turns purplish, wilts, quickly going brown. I plucked them out, but then I saw bigger signs.
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Re: Is this late blight?

#2

Post: # 50871Unread post Sue_CT
Tue Jul 20, 2021 9:20 pm

I don't know. I had a few leaves that were black and I wondered the same thing. I had sprayed with Daconil, but if mine was I expected to see rapid decline and I have not. I have had a fair amount of early blight, which is still showing up even after I removed all I could find and resprayed with DACONIL, using 4 gallons on 16 plants. I tried to get the under part of the leaves as well as the top surfaces and just kept respraying plants in case I missed any areas until it was all gone. I still found an armload more today, although none were bad. I removed them, but its only been about 3-4 days since I sprayed so I didn't repeat it even though they are expecting thunderstorms again tonight and tomorrow. I don't know how I am going to get any tomatoes if the disease is this bad, this early.

I really hope yours is not late blight. Do you spray? I know I try to avoid it most years but I knew it was that or lose it all this year because the rain has been so bad.

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Pippin
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Re: Is this late blight?

#3

Post: # 50873Unread post Pippin
Tue Jul 20, 2021 11:55 pm

I would expect to see some spots in the leaves if it was late blight.

What comes to my mind is this yet-unnamed-to-me disease that I observe in some of my indeterminate x determinate crosses. Some F2+ sp plants are suddenly susceptible for a similar looking issue although neither of the parents were not. Stems gets this brownish hue and leaves wilt. It does not competely kill the plant, neither does it spread to other plants. There is clearly a genetic factor on which plant gets it. Could be fusarium or something similar soilborn, you probably know better. :D
BR,
Pippin

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bower
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Re: Is this late blight?

#4

Post: # 50879Unread post bower
Wed Jul 21, 2021 5:21 am

Tx guys. I don't spray, I just do leaf sanitation - prune out the bad stuff and remove, whatever the cause.
I also weeded out any plants that are prone to disease and therefore 'high maintenance'. Not worth the hassles.

But there are still some problems from time to time, especially when it gets humid and 'hot' by local standards (that means outdoor temps are in the high 70's to low 80's and humidex into the 80's or 90 F).
There's a type of mildew that blows in from weeds in the field, leaf surface looks 'burnt' with red and purple colors and the mildewey surface is under the leaf. Mites also blow in and go nuts especially if or when they get into the high canopy. Both of these problems are directly associated with airflow from outside - they affect the outer leaves of the plants regardless of whether it is new or old growth.

As for the present problem, I have seen it before in the same weather conditions. It does spread to other plants, even with careful sanitation and removing infected parts twice a day. Compared to other conditions we typically get here (Early Blight, grey mold) it is more spreading and harder to control. No sooner you clean the plants up, a couple of hours later there are more affected parts. It pops up in the leaf axils mainly, the little new shoots. It doesn't kill the plants immediately but it can make them very miserable if the weather persists. But the plants will recover if the weather changes and it becomes sunny and dry.

I thought possibly it was the grey mold (Botrytis) simply looking different and attacking different plant parts in the heat/humidity. New shoots in the axils are bound to have some moisture available for spores to sprout.

I always thought that Late Blight would happen in "cool wet" weather but reading last night I see that "cool" is considered 70's-80's F, which is what I would call "hot, stinkin hot" especially when humid ;) They also said that it could clear up if the weather turned warmer and dry, which is what I've seen before. I also expected that LB would spread so fast, your plants would be dead in days. But apparently there are different races of blight, some are less fatal than others.

[mention]Pippin[/mention] fusarium can be seedborne so it could get into your soil when using new seeds of southern source. It isn't usual in the north though, because the disease doesn't survive our winters. Fusarium from what I've seen is quite dramatic and half your whole plant can wilt in a day. This makes it obvious it's coming from the roots vs whatever blights affect the aerial parts.
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Re: Is this late blight?

#5

Post: # 50894Unread post bjbebs
Wed Jul 21, 2021 12:01 pm

I too don't spray anything and seldom water. We've had two rainy periods lasting 3-5 days each in the last few weeks. High humidity and calm conditions have brought on rot. I'm calling PM, botrytis or pythium as being rot.
I try to take out the bad but am not too diligent. Wind and sun tend to take care of it. But 70 deg. nights with a heavy dew doesn't help.
Not sure what you're looking at but has to be weather related.

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Re: Is this late blight?

#6

Post: # 50895Unread post Tormato
Wed Jul 21, 2021 12:07 pm

I've only seen it, and had it, once. This was full blown all across southern New England, and places south and west of here.
Leaves and main stems had patches of brown, undersides of leaves were fuzzy lighter brown (the spores). It wiped out 104 of my 105 plants within 48 hours. The last plant at the end of the last row survived unharmed. Why? I have no idea.

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Re: Is this late blight?

#7

Post: # 50898Unread post Sue_CT
Wed Jul 21, 2021 1:02 pm

That is what I expect of Late Blight. However, Daconil is supposed to be an effective preventative, but useless as a treatment. As far as I know your only chance once it shows up is if you have used preventative spraying. I am not aware of any effective treatment once you have it. So I doubt that is what you are seeing here. I only thought mine could be because I did use an effective preventative spray, but it could have taken hold on new leaves or any I might have missed.

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Re: Is this late blight?

#8

Post: # 50899Unread post bower
Wed Jul 21, 2021 1:21 pm

Weather is definitely the thing, and in this case too many plants too densely packed together. It's been humid anyway but inside the greenhouse it's always up a notch, even if I run a fan.
So this morning it was still raining, hot and humid. This rot was all over the affected plants, although it hadn't made it to the end of the row. Some more pics of the blight, whatever it is.
blight-leafstems-581.JPG
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Re: Is this late blight?

#9

Post: # 50900Unread post bower
Wed Jul 21, 2021 1:32 pm

I did a big prunedown, yup even dipping my pruners in bleach. Not waiting to see the meltdown.
Before and after - don't the plants look fine from a distance? But not fine at all... If I left it for a day it would be toast city.
I didn't take out the plants entirely, just hoping they can vine ripen the fruit at the bottom that were less affected.
One thing about the LB, if that is it, it gets on the fruit as well... I kept a load of greenies to see if the bigger ones will ripen off the vine. These plants are just ready to ripen - first blush on one down the row.
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SB-greenies-off-640.JPG
SB-blusher-637.JPG
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Re: Is this late blight?

#10

Post: # 50903Unread post bower
Wed Jul 21, 2021 1:38 pm

Meanwhile, the wind changed and the temperature plummeted to 55F outdoors. Still raining and foggy too. So that makes a difference to the relative humidity right away, although it is still around 70F in the greenhouse.
Too right about the sun and wind [mention]bjbebs[/mention], as my outdoor plants aren't showing any of this trouble. They have enough to worry about, alright, but not this one. ;)
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Re: Is this late blight?

#11

Post: # 50904Unread post Tormato
Wed Jul 21, 2021 1:43 pm

All I see are leaf/branch issues. From my one experience, along with internet searches, late blight appears to show up mostly on leaves and main stems, not so much the branches.

I have one plant this year, out of about 180, where many branches are simply dying. I'll pull it, if plants around it get ill. It was grown from sent seeds, of a RL that showed up from a PL variety. It may have some weak genes?

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Re: Is this late blight?

#12

Post: # 50905Unread post Pippin
Wed Jul 21, 2021 1:45 pm

Blight or not, I am little jealous as your plants looks gorgeous. :D

May I ask is this plant a named variety or an unstable breeding project? I am asking because it looks very similar to what I see in some individuals in my crossing lines. If it was a genetic susceptibility to something that your other plants can tolerate, you would not need to do much for it. I actually keep these infected plants to maintain a selection stress. When life gives you lemons, you know...
BR,
Pippin

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Re: Is this late blight?

#13

Post: # 50927Unread post bower
Wed Jul 21, 2021 7:02 pm

Well.. I have experience with keeping sickly tomato plants around. It doesn't bring me joy. :evil: In fact, tomatoes are foul creatures. :twisted: Plain and simple. They all get rots eventually when the season ends. And they sure produce an insane amount of biomass - so much material to rot, one could grow them for compost alone.. A greenhouse filled with it at season's end is nothing anyone wanted to clean up. I've not seen diseases that don't spread in a tight space, and presently very overcrowded with 29 plants, so no way I would keep a sick one for selection pressure. Outdoors, sure, why not. But it hardly seems necessary to keep an especially sickly one. :lol:

[mention]Pippin[/mention] this is one of my F7 plants presumably stable and looking to be so. They are a lot sweeter than lemons, but not a good fit for my greenhouse, short stature, lazy disposition etc. :P The sister plant is a better fit for my eating habits, but this one pumps out fruit fast and furious. It also goes down faster at the end of season though. I gave some of them bigger containers and extra ferts at planting this year, just to see if they would show better resistance at season's end... ha!
I do have two of the same plant outdoors, and they are fine. They endured a lot of cold, rain, wind, subzero dewpoints, and came through it as well or better than the others. Easy to pick out of a determinate lineup for the strong semideterminate vertical growth habit. (The plant on the left was just moved out of the greenhouse yesterday so hasn't been through the rigors as yet).
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Second outdoor plant is also doing fine, in a 3 gallon pot. Fruit volume getting close to soil volume, that's not bad for container plants.

SB-outdoor-3gal-668.JPG
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Re: Is this late blight?

#14

Post: # 50929Unread post Sue_CT
Wed Jul 21, 2021 7:56 pm

I have had 13.19 inches of rain so far in July, and there are still 11 days left. I don't know about you but its going to be a struggle just to get a harvest and one worth eating this year. If they make it to ripen they might just taste like water. I had one full sized tomato ripen in the main garden and it was rotten, mush underneath, and I threw it out. I got 5 Black cherry. We so needed a nice summer after the last year and half and so far it has been terrible.
Last edited by Sue_CT on Wed Jul 21, 2021 8:46 pm, edited 2 times in total.

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Re: Is this late blight?

#15

Post: # 50931Unread post PlainJane
Wed Jul 21, 2021 8:40 pm

Better rain than fires like the West is dealing with.
“Never try to outstubborn a cat.”
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Re: Is this late blight?

#16

Post: # 50940Unread post Sue_CT
Wed Jul 21, 2021 9:57 pm

Huh, I had a post that never showed up. I must have missed hitting the final "submit". Anyway, As we have learned in the last year and a half, there are much worse things than a summer with no tomatoes, but a healthy and productive garden can be a type of therapy for what ails you. It would have been appreciated. If I can keep it going until then maybe fall will turn it around.

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Re: Is this late blight?

#17

Post: # 50941Unread post Pippin
Wed Jul 21, 2021 10:04 pm

You have done the right decisions with that devil, [mention]Bower[/mention]. :D Your tomatoes looks really good, espesially as they are growing in containers. My container plants looks miserable compared to these.

I have very dry growing conditions and much smaller plants in the tunnel where my main selection lines are. That is where I have not bothered to remove the diseased plants of similar look. This reminds me that I have way too luscious growth in the other green houses where my larger tomato plants are, I should probably do some preventive actions and show my pruning shears to all of the plants there. I would never keep a diseased plant in those conditions.

We have also high temperatures but a serious drought. Germany gets all the rains, as you may have read from news, the high pressure has parked over Russia and Eastern Europe. Not a drop of water to us in weeks during the best growing season. :(
BR,
Pippin

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Re: Is this late blight?

#18

Post: # 50944Unread post Paquebot
Wed Jul 21, 2021 10:27 pm

Like Tomato, I also have seen late blight once. That was 2008 and a 1.6 acre community garden went down in virtually 2 days. Plants in SW corner had it one day and NE corner the next. The odor a week later will never be forgotten. Wisconsin 55 resisted long enough for the fruit to be salvaged but eventually went down. In the entire complex, two plants never lost a leaf and they were Bosu, a variety with unknown or shady origins.

Anyway, I do not see any late blight in any of the above pictures. No need to panic.

Martin .

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bower
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Re: Is this late blight?

#19

Post: # 50954Unread post bower
Thu Jul 22, 2021 6:49 am

Well I am relieved if it is not LB!! Maybe it is another stage of the horrible mildews which are really a scourge in the humid weather here. I was not very thorough in my yearly attack on the weeds that harbor that. Or perhaps it is a hot/humid weather mold of some kind, or a different m-o for grey mold in the heat. The upper canopy in the greenhouse is a very hostile environment in the scorching weather, with mites as well as heat to kill the blossoms. With so many flowers high up, these plants dropped a lot of their dead ones as little mold-bombs into the foliage - the kind of thing I would clean up if it was at eye level instead of needing a ladder.

It seems like everyone is having extreme weather of one kind or another this summer! Every time the heat breaks here, we drop into the 50's for several days, so wild temperature swings. We were so grateful for the thunderstorms that blew through a couple of days ago and rained heavily here. It has been so hot and although humid, very dry - a water ban was announced the same day in a community just up the shore from here. I'm really lucky to have an excellent deep well and never short of water for my crops if needed. I hope your drought breaks soon [mention]Pippin[/mention] . And [mention]Sue_CT[/mention] get some sun!

My plants have really been selected to do well in a container. The potting mix has been greatly improved this season by following bjbebs advice and using well rotted horse manure to amend it. Much better moisture retention, so less watering and less shrinkage of the soil volume as happens when the kelp meal has been consumed. I definitely would recommend it.
Also getting in the mood for some pre-emptive pruning.
My cuts from yesterday are looking all clean, and no sign of a return engagement with the mystery blight as yet. :)
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Re: Is this late blight?

#20

Post: # 50957Unread post brownrexx
Thu Jul 22, 2021 7:47 am

I don't know for sure if you have LB but the 2nd and 3rd photos sure look suspiciously like it.

If you do have LB you will know it because it spreads FAST. Lower temperatures at night with high humidity are ideal conditions for LB and several years ago my plants were infected. I pulled some trying to save the rest but to no avail. Most of my plants were dead or dying within a week. The tomatoes also had hard brown blotches on the skin.

There is no cure, only prevention.

My plants are also looking a bit worse than usual due to the high heat and lately the frequent rain. I have Early Blight. I have sprayed with a copper solution but I need to do it again.

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