Late blight questions

[RomanX]

My plants have late blight, diaganosed after comparing pictures and symptoms. Yesterday, they were healthy and green but today they're definately sick:black splotches on major stems, lesser stems and LOTS of leaves withered, dead and crumbly as is burnt to a crisp by the sun.

only AFTER pruning dead, dying and ailing stems and leaves, did it occur to me to take pictures (before" my plants looked like they "wore" maxi skirts; now, they 'wear" minis! lol).

Questions:
What should I do now to have all the green fruit continue to grow and ripen within the next 28 days? I'll pinch off the yellow flowers tomorrow, but what can (or should) I do?

Should I spray with a fungicide?

A few of the smaller fruit (mostly 1/4 oz, with one 4 oz) had irregular greyish, mushy spots, so I threw them away; the mature siZe is ~10 oz.

Will the bigger green fruit be okay with or without the spray??

Here's some pics. You can see that there's still alot of green fruit . . . .

[RayR]

You should contact your county extension agent to confirm you have Late Blight if not something else. USABLIGHT.ORG shows confirmed reports of Late Blight in the far western counties of N.C.
If you actually have Late Blight then there is not much you can do except trash the infected plants and fruit. Fungicides may help as a preventative but once the plants are infected it's extremely difficult to control.
See the Cornell web site for lots of information on Late Blight.

[b54red]

Are all your plants infected? Are you sure it is LB and not gray mold which is very similar in appearance. Gray mold usually starts on the lower and interior leaves first and then moves on up the plant. Late Blight when I have had it started first on the upper half of the plant and quickly killed the plant once it reached the stage where it was causing stem lesions and lesions on fruit. I have beat back Late Blight twice with minimal losses. Once this summer in July right after a rain I saw what I thought was LB starting on one plant so I immediately sprayed every plant in the garden with the diluted bleach spray. The first plant that had it died as did the two other closest plants to it but no other plants were infected. I also lost every plant in my garden the first time I had it because I didn't recognize it for what it was and just used a battery of fungicides to no avail.

Whether you have Late Blight or gray mold the treatment is the same but if it is Late Blight it may already be too late to help. Spray every surface of the plant with the diluted bleach spray making sure to spray even the soil under and any plants nearby. The next day remove what shriveled stems you can and then spray again with the bleach spray to make sure you got it all. If it comes back in a few days then it is already systemic and can't be stopped at that point especially if new growth is affected. If it is gray mold it may only slow it down if it has gotten inside the plant but continued spraying when new infections of gray mold show up will keep it at bay enough to let most fruit ripen. If it is gray mold then follow up with a copper spray but if it is the more virulent Late Blight you need to remove any plants that are having continued destruction happening to them. If it is Late Blight then even your new growth will be affected within a few days but if it is gray mold the plant should continue to put out healthy new growth that isn't stunted and discolored.

I have several plants showing gray mold symptoms right now and I will be spraying them tomorrow with the bleach spray. I will also be keeping an eye out for any Late Blight symptoms since we had a bit of rain the last two days. I hope you only have gray mold which is trouble enough especially if you are getting any rain and high humidity. If it is Late Blight I am very sorry.

Below is a link to the thread on the bleach spray. Be sure to read it carefully before using it and be sure not to breath the spray mist when applying it.

http://tomatoville.com/showthread.ph...t=bleach+spray

Bill

[zipcode]

Your pictures are not that good, especially the critical one with the fruit. But I'm inclined towards late blight.
The late blight will affect your fruits (any affected fruit is impossible to get anything out of it). So topping the plants isn't going to achieve anything.
Spraying with something preventive will help some in the long run, but you _need_ to have good weather. You can stop a reasonably advanced LB if you have dry conditions (with 2 weeks of dry weather LB will stop by itself without any spraying if stems are not badly affected), otherwise it's basically impossible.
Around here commercial growers use with some success Ridomil Gold after disease has started, but it's probably reasonably toxic.

[b54red]

Originally Posted by zipcode

Your pictures are not that good, especially the critical one with the fruit. But I'm inclined towards late blight.
The late blight will affect your fruits (any affected fruit is impossible to get anything out of it). So topping the plants isn't going to achieve anything.
Spraying with something preventive will help some in the long run, but you _need_ to have good weather. You can stop a reasonably advanced LB if you have dry conditions (with 2 weeks of dry weather LB will stop by itself without any spraying if stems are not badly affected), otherwise it's basically impossible.
Around here commercial growers use with some success Ridomil Gold after disease has started, but it's probably reasonably toxic.

I have had LB at least 4 times over the years and have never seen it stop without very intense treatment and even with intense treatment it is an iffy proposition. Gray Mold which I think is what the poster is dealing with is far easier to stop but it has the symptoms that mimic Late Blight and can definitely fool you into thinking you have LB when you don't. Gray Mold can affect the fruit in advanced cases and stem lesions are common. However with Gray Mold you don't get that white spore mess on the underside of the leaves nor does it attack the new growth early in the disease although it can eventually if left untreated.

The easiest way to tell early in an infection if you are dealing with Gray Mold is look for it to show up on the lower and shadier portions of the plant first. If something similar hits all over or more on the upper and outer portions of the plant first it is usually LB and must be treated as soon as you see the symptoms if you want to have a chance to stop its spread.

Bill

[zipcode]

I had Late Blight basically every year. A few years ago it has been bad, I dreaded its inevitable return, it has completely wiped my tomatoes a few times just when they were starting to get some colour.
However more than 50% of times it had stopped by itself, and plants lived happily until frost. I do not spray with anything, because I don't live near my plants, I only 'visit' them every 2 weeks or so.
The conditions here are not the same as yours however, we don't have serious heat, and the nights are always cold. We do have fairly high humidity and heavy morning dew, but I think the low temperatures will maybe not allow it to act as fast.
I never had gray mold but from pictures on the net, the symptoms on the fruit seem easy to differentiate from LB.
LB has these diffuse spots forming on the surface of the fruit, usually in the part hidden from the sun, and the characteristic is a sort of 'bumpy' appearance at first, also rather shiny.

The single most useful prevention against foliar diseases remains a small (or bigger) greenhouse. Direct contact of water on the leaves makes a huge difference. It's not completely bulletproof no matter the weather, but it does make the biggest difference, and it's the least toxic as well.

[RomanX]

Saturday, all my tomatoe plants were green and healthy

Sunday, they were NOT
I sprayed with the bleach solution
I pruned off non-productive stems (each plant had from 1 to 3 stems)
I picked off dead and partially brown. crinkly leaves
I picked and discarded affected fruit (mostly green but there were 2 red)

Monday, I went to the Ag Extension office
Sack of examples: affected leaves, branches, green and red fruit. . .camera with new pictues (posted below)
They said the plants had a fungal tomato (fruit) rot. . .using bleach as a fungicide was not approved, in fact illegal. . . I should spray with a copper fungicide and most of my green tomatoes should be okay, but even if I did spray I'd prolly still lose plants and fruit

I opted to continue with the bleach regimen and to end my tomato season early (after all geen tomatoes had ripened). I pinched off aall yellow flowers from ALL my poor plants.

I called the Ag office for advice on how best to end the tomatoe season,
I read on the Internet 2 conflicting methods: stop watering and all remaining fruit would ripen together...and gradually reduce (but don't ever stop entirely) etc.
I didn't get an answer either wsay so I STIULL don't know how best to end this nightmare!

With 3 probable diagnoses, I'm more confused than ever: what is ailing my plants?? How do I end this season??

[RayR]

"fungal tomato (fruit) rot" isn't a descriptive diagnosis.
Couldn't they at least give you a name for the disease?

[ChrisK]

Since you are in NC you can submit pictures to NCSU plant pathology clinic free of charge for a diagnosis. You need to send good pictures though.

You can also send in leaf and stem samples (or drop off in person) and a check for $30 and they will diagnose for you. Needs to be before any fungicide treatment though.

http://www.cals.ncsu.edu/plantpath/extension/clinic/

[zipcode]

Pictures of the affected fruit are what is needed here. Especially green fruit.

[RomanX]

Originally Posted by zipcode

Pictures of the affected fruit are what is needed here. Especially green fruit.

Sorry, pickeed and threw...they rolled downhill: I can SEE them but not go get them! (and it's too far for my camera. . I tried.) my condition prevents it; here in the foothills, in this area at least, the only flat, level place is where buildings are. . . the parking lots are merely paved over hills!

That's one reason I have a container garden on my back patio!

Here's a description of affected green fuit: 4 inch fruit had a light grey, perfectly round discoloration with a few scattered dark brown/light tan specks inside this circle, usually on the sside; smaller green fruit only hadd a combination of the spots (but on the bottom, an indistinct lighter coloration and/or the whole fruit was white or a lighter color than normal.

Red affected freuit had black irregular spots (lesions , , they were like scabs: raised and hard) on the bottom that ccoalesced into one LARGE, caved-in, rotting, dripping / oozing cavity that would keep growing as it rotted the fuit from the bottom toward the top.

[zipcode]

Well, it's quite hard to imagine what you said exactly, doesn't quite sound like LB.
Here is a picture that I think shows great the LB symptoms that can't really be mistaken for something else:
http://smallfarms.cornell.edu/2011/0...orting-system/

The one on the left is at the beginning of infestation.

[RomanX]

todayh, the fourth day post-spraying, are pictures orf both green and red fruit - picked today and phot taken BEFORE throwing them away

[RomanX]

Thank you b4red: I sprayed with that bleach solution and now am optimistic that my plants are recovering: they'rem starting to put out new (heaolthy) growth plus most are flowering!! I still think I need to trerat again (see pics of fruit from today, posted as an update to zipcode)

and ChrisK, too! I immediately went to that link and successfully uploaded images / started a request for diaGnosis!

Hopefully, with all this help, I will soon have lush, green, producing plants again!

[zipcode]

Not LB on the ripe fruit, and hard to say, but probably not also on the green.
Keep spraying regularly and if the weather gets better, things will be back to normal probably.