LATE BLIGHT FUNGUS ON TOMATOES - HOW TO TREAT TOMATO

[cynthia_h]

Just read this news article on "late blight" appearing this year and killing many tomato plants in (north?)eastern states.

Sounds pretty bad; a Cornell University professor is quoted in the article, so it's not just fear-mongering. A real threat.

https://www.comcast.net/articles/news-science/20090703/US.Farm.Scene.Late.Blight/

Cynthia H., on a "drive-by"

[snowleopard394]

Yeah, it's not just fear-mongering. I'm gardening in a community garden plot near Cornell, and a couple people have already reported late blight on their tomato plants that are quite close to mine (just a few plots away from me). I'm really worried... had to spray all my tomato plants yesterday with fungicide, but I noticed that one of my plants has a stem lesion. I'm hoping it's not the blight - it doesn't look quite like the pictures online. Even so, with late blight *that* close to me it's probably quite likely that that's what it is.

[snowleopard394]

Just to update you guys on this situation, almost all of my tomato plants have it now. This thing has been spreading like wildfire throughout the community garden plots that I'm at. Almost all of the plots have it now (if not all).

As of July 1st, late blight had been detected in: South Carolina, North Carolina, Virginia, West Virginia, Ohio, Maryland, Delaware, New Jersey, Pennsylvania, New York, Connecticut, Rhode Island, Massachusetts, New Hampshire, Vermont, and Maine. If your tomato or potato plants are in any of those states, you need to think about fungicide applications ASAP... this disease can spread several *miles* in the wet weather conditions that the eastern U.S. has been having.

[Duh_Vinci]

Is there any particular fingiside you use and know that it works?

Regards,
D

[The Helpful Gardener]

Stick to the usual recommendations we make, DV; fish, milk, compost tea as preventatives, copper soap if you actually are shooting at something... using harsher stuff will kill ALL the fungi and as over half of them are beneficials, you are just weakening the plants more...

This is an airborne fungus unlike most of our other tomato issues, so even if you started with squeaky clean you are not safe. I have seen some early spotting on leaves despite stringent preventative measures and I've started with copper soap, but who knows? Cutting off all your foliage except for a few leaves on top eliminates a lot of surface area to infect and won't hurt fruit production; I was already pretty pared down but I am whacking off more foliage today; potatoes too as this thing hits the whole family, not just tomatoes.

This is a nasty character spread about the entire country by one big box store relying on a singular mass grower. Let this be a lesson to us all; plants should be locally grown and locally sold. We are shipping our issues around the world with little thought or oversight, and this is another data point in a laundry list of human propagated diseases we gardeners are going to have to deal with for a long time... scary stuff...



HG

[Decado]

I'm in Minnesota and I'm getting late blight, I don't think it's just the east coast.

[jamesy]

Oh dear...NY is a little close for comfort,first ive heard about this.Ive several tomato plants,ill keep watch for any signs..hoping I wont see any.

[cynthia_h]

Be sure to read the entire article. Gardeners may have affected plants and not know it--yet.

If so, remove them *immediately* and place them in sealed plastic bags in the trash. Do NOT compost them.

Perhaps the remaining plants will escape if you take prompt action.

I personally would recommend that anyone who purchased plants (esp. tomatoes, potatoes, eggplant, and other Solanaceae) at any of the chains listed in the article, consider those plant(s) to be affected.

Phytophthora infestans, aka "late blight," was the organism behind the Irish Potato Famine. It is not to be taken lightly.

Cynthia

[snowleopard394]

I've been using chlorothalonil on my plants (not organic, but it's either that or definitely lose them all, what with everyone else's dying plants and too much rain). That combined with pruning off all diseased parts of the plants on a *daily and thorough* basis seems to be making a huge difference. I've lost 2 out of 21 tomato plants so far because they both had a stem spot right at the base of the main stem. But the number of spots we're seeing is decreasing every day. We've got a bunch of plants that had late blight symptoms, but after pruning off the spots, they haven't developed more spots in the past couple days. We'll see what happens, but I thought I'd let you all know just in case late blight comes to your area.

If late blight is near you, consider applying chlorothalonil. It's quite effective if you cover your plants with it in time (before they get it... which might not show up till 5 days after the fact). For organic gardeners, copper applications are supposed to be the most effective. The problem is, copper washes off in the rain, and rainy conditions are what the fungus likes most. That means copper is not very effective compared to chlorothalonil.

[jamesy]

Thanks Cynthia H and Snowleopard , ill follow the advice except the spraying part , I guess if my plants get it they get it , ill be watching closely.
I had good results last year and didnt do a thing but water them,I cant bring myself to spray them with chems.Not that I'm an organic stickler..just don't want to spray them.
Quite possibly and even likely is I don't have a clue what I'm talking about but I'm sticking to it..lol

[The Helpful Gardener]

[url=https://www.pesticideinfo.org/Detail_Chemical.jsp?Rec_Id=PC34550]Chlorothalonil[/url]is a known carcinogen and pretty toxic to us (EPA calls it an acute toxin), but it is h*ll on wheels for soil biologies. Mortalities of fungii, bacteria, and protozoa are profound (like 80%), and it shows accumulitive properties in water and extreme toxicities for aquatic creatures. Sure it's "effective"; it kills EVERYTHING...

So we when we kick such huge holes in our biosystems, what would be the response in Nature to these holes? Remember we have a hard to control fungus that is showing early signs of pesticide tolerance, and we are opening real estate to it like nobodies business.

I will let you in on a little secret; this year with me out of work, we purchased a lot of our plants with a gift card somebody gave us to Big Orange. I got the bad plants but they still look healthy and clean for the most part, a few spotted leaves but fish, milk and coppper soap when I see a real issue, are controlling things. Jamesy is right as rain; I'd rather eat store bought than spray my plants and soils. SnowLeopard is taking the line I am seeing promulgated by state extension sevices everywhere and I cannot fault him for that, but it is a bit of bad policy in support of worse science. Cynthia is also cautioning safety, and I cannot fault her for that, but I will keep my plants until I see clear evidence they are going bad, THEN I'll dump them. I feel good organic culture, stressing healthy leaf colonies of biodiverse microbiota, can keep this off. Using Streptomycetes and Trichodermacan reinforce populations with biological predators that can meliorate, if not mitigate infective populations... we CAN fight this organically, and I intend to do just that... if I lose so be it and I will destroy plants, but not without a fight...

Next year I will be trying [url=https://www.thompson-morgan.com/seeds1/product/899/1.html]'Ferline'[/url] and [url=https://www.victoryseeds.com/catalog/vegetable/tomato/articles/tomato_legend.html]'Legend'[/url]; two cultivars noted for late blight resistance... is 'Brandywine' the new 'Lumpers'? Can Scott save his tomatoes and potatoes? Stay tuned...

[snowleopard394]

You're right that it's not the best thing for the environment. It's quite bad if it gets in waterways.

However, when it comes to what I put in my body, I will share my logic. I do not limit myself to organic produce in stores, so feel free to criticize me for that if you like. But if that is the case (that I don't only eat organic when I buy my food), chlorothalonil is probably the least of my concerns where "toxins" from food are concerned. Commercial farmers in the eastern U.S. will be spraying their plants with more potent and *systemic* fungicides this year. Chlorothalonil is not systemic to the plant. That means if I eat a normal conventional tomato, I can't help but eat the full dose of fungicide. At least with chlorothalonil, I can probably get the vast majority off with a little soapy water once I harvest.

It causes kidney and liver tumors in rats and mice, but not dogs, if fed at unrealistically high doses (a billion times the estimated human exposure) for 2 years. There was another study showing that the mechanism of carcinogenicity is not likely to be due to changing DNA. If the mechanism were due to changing DNA, then you could expect even a tiny amount to increase your risk of cancer by a proportional tiny amount. But that is not the case. You can read here about how the carcinogenicity risk was determined (keep reading the whole thing - the page focuses on chlorothalonil as an example, at the bottom):
https://pesticides.montana.edu/PcideProfiles/carcinogens.htm

I hope there are no hard feelings here. I totally respect your decision not to use it. But I think we should all decide for ourselves what is acceptably safe. In my case, I'd prefer not to eat potential residues of chlorothalonil... but I'm fairly comfortable with the risk level. And if I don't spray my plants with this, they *will* die, and fast. I'm seeing it happen in neighboring plots. And if that does happen, I will definitely be eating worse stuff from the store.

[jamesy]

I think as far as I go with tomatos , if my plants don't survive unsprayed ill be having plain burgers this year..simple.
The more I read about this fungicide the less likely I'm ever going to buy store bought tomatos again.
Already I wont buy store bought corn on the cob , no reason other than last year for the first time in my life I had corn straight from the field to the pot,I could never eat store bought again.

Last night we had a huge storm for about 5 hours or more , perfect conditions to kick that disease into high gear from what I understand.My plants look fine so far..fingers crossed.

[applestar]

It's always a personal choice in your garden isn't it? Hopefully, everyone will make informed decisions.

People who've been reading my posts know I grow organically by choice, but I also know that, especially under emergency situations, it won't be easy to kick the "chemical habit" if you haven't been, because the micro-ecosystem around the garden will not be as bio-diverse and all around healthier, so you'll be forced to use that "multi-syllable shot of something".

No doubt about it, it's a Catch-22.

[jamesy]

I think a large part of the problem with making informed choices is there are limited sources for this information.
For example , if it were not for this forum I wouldnt know anything about a late blight , its certainly not mentioned on the news which is very strange I thought.
I visited a local plant nursery yesterday , none of them from the checkout girl to the manager knew anything about a late blight , at least thats what they said , I couldnt help notice a brisk trade in tomato seedling plants...another strange thing this time of year.

When I asked about the sprays they told me they didnt stock it , within a minute I found it on the shelf , the toxic ones and the organic ones.
I gave up at that point as I felt id be better off getting my advice here , thanks everybody.

[The Helpful Gardener]

Jamesy is right; the lack of credible info is the hardest part of informed decision making. It is made doubly hard by policy specifically designed to muddy water and make it harder yet (like the inert ingredient, which we have answered by calling them "other ingredients" instead of inert, a pathetic nod to the fact that these are often more poison than the active ingredient! Contrary to the old saying, it is the things we do not know that hurt us...)

The chemical culturing of our food crops has been touted as a "necessary" evil, despite the continual example Nature sets to the contrary. Time and again we return to these natural systems as we learn the failings of the "modern" methods. SnowLeopard it is not hard feelings on our part, it is a sadness for me that you will continue to poison yourself and your soil and the creatures there. I fervently hope I never get my "told you so" minute; I wish there was no need for the stuff at all while I am wishing. We have always allowed for both sides of the discussion when done in a sane and rational manner and you ain't done nothing but, so good on you. I respect your personal decision while disagreeing vehemently. But ask yourself why an ex-grower who has put down in a day the amount of pesticides you will use in your life, someone who was trained and lived in the better-living-through-chemicals world of plant culture has gone a** over elbows green.

HG

[Duh_Vinci]

I completely agree with what Jamesy said.

It is indeed a lack of information that is readily available. And yes indeed, if it was not for this forum, I would be using the the very first (and very last bottle of Chemical Fertilizer I bough in early March)...

I never actually used it, still sitting in the garage This is my first garden, and all I've used up to date was Alaskan fish fertilizer (at the transplant) while adding natural kelp and natural bone meal in small doses as the season went on.

My indeterminate tomato plants are as high as 9'+, and all bear fruit,even standard Brandywine is loaded with fruit (while many report that only a handful of fruit produced throughout the season). More pant than I can manage, but what can I say, I'm learning as I go, later plants I've learned to keep to max of 3 stems, and those bare just as much fruit as the "monsters" set a month earlier.

So while it appears that I can grow veggies, controlling the disease is my next challenge.

Ordered that Fish emulsion, ordered the copper soap, got a gallon of milk, and two 2gal sprayers, one for the copper soap application, one for the milk and fish... Stopped by 3 stores, and one nursery, very very limited selection of organic materials and no copper soaps! Fish emulsion is 5-1-1, which I think is a bit too much from the nitrogen perspective this late in the season. So online ordering as a breeze!

Wish me luck, hoping that this disease does not take over my garden!

Regards,
D

[jamesy]

Well........thanks for the comments , I'm a newbie too and its just an observation,mindboggling but there it was.
Scott , I never gave organic a second thought and didnt much give any thought ..I'm seeing where you are coming from totally.

I don't consider myself Organic or a treehugger or any of the stereotypical characters that are often portrayed , just an average guy that wants food to be as it used to be and respect the earth while I'm using it..if that makes me Organic or even a treehugger ill live with it..come to think of it I love the trees around here
Ill be sticking close by for tips if you don't mind.Firstly I got myself some poultry manure ..smells pretty bad , big ol'bag of it , this is going to be the business when diluted for my garden and veg ? Should I go easy on it or go to town ?

[The Helpful Gardener]

Easy with that stuff; the ammonia in the [url=https://en.wikipedia.org/wiki/Urea_cycle]urea cycle[/url] is about 40% water-soluble, which is one of the things we don't like about blue goo. Better than one hundred percent, but not as good as plant based fertilizers or fish... Good bridge product (from chems to organic) and a fine compost kicker; it locks up there pretty well... just go easy and build the biologies it needs to release and store efficiently in the soil and you'll be fine

HG

[webmaster]

Article in the [url=https://www.nytimes.com/2009/07/18/nyregion/18tomatoes.html]NYTimes discusses tomato fungal infections[/url] rapidly spreading across U.S. North Eastern states and through the Mid Atlantic. Tomatoes are dying or being discarded by farmers across the region. The seedlings have been found as far as Ohio.

One possible source of the infection is a nursery that sold it's tomatoes via big box stores including Home Depot, Lowes, Walmart, and Kmart.

Authorities recommend that home gardeners inspect their tomato plants for late blight signs, which include white, powdery spores; large olive green or brown spots on leaves; and brown or open lesions on the stems. Gardeners who find an affected plant should pull it, seal it in a plastic bag and throw it away, not compost it.

[img]https://graphics8.nytimes.com/images/2009/07/17/nyregion/blight.large.jpg[/img]

[The Helpful Gardener]

Pulled and tossed my first plant, despite strenuous effort to mitigate the problem organically. Other's still seem ok; I am waiting and watching. Dug my Yukon Gold taters (this IS the same disease that caused the Great Potato Famine), and found a few that may have been first stage infection, but most are still healthy. Keeping an eye on tomatoes as well as the Fingerling and Peru blue taters; more on this soon...

HG

[!potatoes!]

many market farmers in my region have lost their entire tomato crops. was just visiting some friends' farm last night, pretty depressing, looking at what, two and a half weeks ago, was almost a thousand-dollar tomato crop...

[The Helpful Gardener]

In a related (Solanum and Lycopersicon are both nightshades, susceptible to the dreaded disease) note I got the potato crop in this week ahead of any infection. Despite devastating losses to the traditionally planted Fingerlings from voles, I still brought in in thirty five pounds of taters. Yukons were biggest, Blues were most prolific. Roasting has been the order of the day; just a little herb and garlic infused oil and a bit of sea salt. Blues are winning the taste tests so far...

Still eating cherry tomatoes and eyeballing a few ripening fruit on the others; sun was good again today but it was cooler and drier too. First time I've had to water for a while thankfully... still no signs of worsening issues

HG

[Quirky]

Chiming in perhaps a little on the late side.....I had thought my tomatoes were just getting normal late summer leaf die-off on the bottom, but no, it's definitely blight. So this is what I'm doing and lessons learned so far....

I'm in central NJ and it's been so durned wet all summer....in hindsight I wonder if NOT mulching with hay would have been the better option. Or at least pulling it off after all the rain we've had lately.

I have one 4 x 12 raised bed that's all tomatoes (I think 30 plants in all), supported with Florida weave and some stakes. All raised from seed from Seeds of Change by me, no big box starts. (IIRC I have 12-15 different varieties but my helpful toddler pulled all the markers so I'm having to do detective work to figure out what's what.) All organic methods so far.

Before the blight came I had gone through and pruned all the leaves off the lower 8 to 10 inches but in hindsight I wish I had kept up with the pruning even more to keep the air circulation even better.

I am still getting ripening tomatoes and I have a ton of green ones so I'm trying to salvage what I can, pruning off all branchlets with any diseased leaves. I'm seeing mostly leaf spots, very few affected tomatoes and no stem lesions. But at least so far even after very heavy pruning I still have enough unaffected foliage that I'm hopeful the plants will survive long enough to get more ripe ones.

FWIW, my paste tomatoes (San Marzano and Roma) have done the best, producing heavily in spite of the blight and ripening well. My cherries and grape tomatoes in different beds are so far unaffected (knock wood). It's the slicing tomatoes that look like they're potentially going to be lost if they don't ripen and the plants succumb. Tigerella has also done quite well although prone to catfacing with the rain.

Next year I will definitely rotate and not put tomatoes in this year's main bed although unfortunately unless we take down some major trees I don't have the space to do longer than a biennial rotation. I will probably add 3-4" of compost and mulch when the tomatoes come out and try to get in a crop of overwintering greens if I can.

[The Helpful Gardener]

Thanks for that Quirky; always good to get a take from the trenches. Sorry for your losses but sharing the info gives meaning to their sacrifice. They will be missed

Just got off the phone with pal Lisa, one of my radio buddies; ([url=https://www.wtic.com/topic/play_window.php?audioType=Episode&audioId=3683645]this is us a few months back[/url]). She has been having good luck with nettle tea but cautioned against dosing rates as it can be herbicidal at higher doses. She dilutes about 8:1 (water to tea) for prevention and 5:1 for curative use, and has graciously coughed up a gallon for me to play with (with a caution on smelliness; we'll see). While it is touted for [url=https://www.attra.org/attra-pub/compost-tea-notes.html]antifungicidal and pesticidal qualities[/url]for plants, it has been known for years as a [url=https://www.liveandfeel.com/medicinalplants/nettle.html]human health tonic[/url]. One of those ancient secrets we lost in the rush to chemicals? Lisa says yes and she's the one who got me organic, and she says she is doing ok; hasn't lost a plant yet, despite seeing first signs on a few plants. Good enough for me; I will let you know how my trial turns out...

HG

[Quirky]

Is she brewing from fresh nettles or from dried? How is she brewing the original tea that's then diluted? Is she using it as a foliar spray?

Nettle tea is excellent during pregnancy among other things.

[The Helpful Gardener]

Lisa used fresh from her yard (she has had a patch of big bull nettles for a while and finally made use of them). Just mahed 'em in a bucket to my understanding; a passive brewing, in compost tea parlance... As foliar spray for blight, insects and foliar feeding, and drench as soil tonic and fertilizer...

HG

[applestar]

I've been wanting some nettles -- the stinging kind -- I've got plenty of dead nettles, but was loath to actually buy seeds (I'm a cheapskate, what can I say? ) but FINALLY had a good big clump volunteer this spring, which was allowed to go to seed, and am now spotting several smaller volunteers (Don't know if this is from the new seeds or if I had some more growing) I'll soon have enough to brew some tea! The BIG question is shall I brew this tea for the garden or for myself (Nettle leaf tea is highly nutritious and has a lot of medical benfits you know. I used to drink them while I was pregnant....)

[Quirky]

Just coming back to report that I haven't lost any plants (so far). I've pruned the heck out of them so they're mostly just vinestalks with tomatoes on them and a few leaves on the top, and I have had a few blighted tomatoes, but I'm still getting ripe, healthy tomatoes. Yay!

I certainly can't ascribe it to my superior gardening skills, but I'm very happy and grateful that my plants didn't totally succumb. My CSA ripped out a HUGE plot of tomatoes -- I saw them before they got ripped out and it was a terrible sight.

[The Helpful Gardener]

Quirky, thankfully we don't have to grow as many as a CSA; I am not the only organic nut in the family, as brother Dennis works at an organic CSA and thankfully was on top of it, yanking many plants in first stages, which on that scale is the best remedy (speed is the most important factor). You and I can be proactive and intensive on a plant by plant basis, which brother Dennis has pointed out they can ill afford, but at least being more proactive than reactive has been successful for his operation and they have not had to haul them all out yet (although he still does not rule it out).

I am still seeing early signs and cutting off leaves or picking fruit accordingly; as long as you keep it out of the stem I think you can fight it (Lisa says the same). Once it is in the stem, chuck'em...

S

[trigger]

We've been trying the nettle compost tea since our plants were hit pretty hard by the late blight.
So far, twice daily sprayings of the tea and pruning have slowed the progression quite a bit. We are seeing quite a few tomatoes start to ripen, so there is hope!

[The Helpful Gardener]

Glad to hear trigger; same here

HG

[funnyguy]

Just came on to ask about my tomatoes with a picture and saw this thread. The link to the article no longer works. Can someone tell me if this is what's wrong with mine?

The left one is a cherry tomato, which has the brown slotches, and the other is a better boy bush, which has the white-ish crawl-ies. They looked fine until I moved them into the greenhouse for the cooler weather, and they've started looking like this.

Thanks!

[img]https://i461.photobucket.com/albums/qq332/funnyguy/tomato-problem.jpg[/img]

[The Helpful Gardener]

The left looks like first stage blight and the right is certainly a leaf miner ...

HG