Late Blight coming our way?

[Elliot]

I read in the Long Island Newsday, our local paper, that the Late Bight which devistated tomato crops two years ago is making another appearance this year. The article said that commercial tomato growers are using a powerful antifungal but this is not available to home growers of tomatoes. Is there anything we can do before trouble begins?

[Talon1189]

Start spraying weekly with Daconil is all you can do as a preventative

[Elliot]

Is this toxic to the plants or to people?

[b54red]

I don't know yet whether I have it or not; but every plant in my garden is sick right now and I don't know if any will recover.
We had a very long dry spell from May til about 3 weeks ago when we started getting these little afternoon showers that would wet the plants and wash off the Daconil but not really wet the ground. Then it started really raining heavy last Tuesday and Wednesday. Since Thursday afternoon we have seen no sun and the rain has only stopped for a few minutes until 5:00 Sunday. I went out to pick what fruit I could but almost all were split so bad they looked like they had exploded and the plants literally look like someone sprayed them with diseases. We are still supposed to get rain for the next week but only scattered showers but I fear the let up may be too late.
It is very hard to keep the plants healthy with near 100% humidity 24 hours a day for a week. I am thankful now for the drier weather earlier in the year which allowed me some success with disease prevention. I really wanted a few nice heavy rains; but not this much for this long.

Since the plants looked so bad and so sick I took drastic action and sprayed them with a stronger than normal bleach solution. At the strength the solution was applied I should get serious leaf burn but my plants went from fairly good looking to wrecks in 7 rainy days. I saw evidence of nearly every tomato disease I have ever seen all at once today and it was an ugly sight. If the spray kills the plants then I will just have to make do with some seedlings I am preparing for fall. The only thing that still looks fairly good in the whole garden are my okra and a couple of hot pepper plants.

Even if I lose all my plants for the rest of the summer it will have been worth it for us to get this much needed rain. It has been so dry around here that some older trees have even died from the drought. Another plus was a couple of days with temps below 90, which is a real treat in July down here.

[carolyn137]

Originally Posted by Elliot

Is this toxic to the plants or to people?

No less so than Rotenone.

So after years and years of defending Daconil I'll do it again, but anyone is free to do their own searches. The issue to me is that I don't care if a product is natural or synthetic, what I care about is toxicity to humans and pets and the environment in general and Daconil is THE most used ant-fungal in the world and has been so for over 20 years so there's lots of data for it for those wwish to do their own research. be sure to look at EXTOXNET when you do b'c it's no biased as so many sites are.

Elliott, someone else from LI was also asking about the Late Blight reports, I linked to the Cornell blog about that and also suggested that she take a close look at her plants and decide if they have gray Mold since that disease can mimic LB.

I also noted for her that there's a Cornell Coop Extension on LI if she needed help with diagnosis.

But I strongly advise those who are worried to spray on a regular basis with Daconil, either the Ortho brand or the Bonide Fung-o-nil, both of which have the correct concentration of chlorothalonil which is about 29% in the concentrate which then needs to be diluted.

Those of us in upstate NY went through all of this, what was it, two years ago? So lots of experience with it. My plants never were infected but within maybe a three mile radius of where I am there were fields of tomatoes and potatoes that went down.

The choice one has to make in situations like this is whether to spray with a product that's KNOWN to help prevent LB, nothing is perfect, and the various Cornell sites on this are very helpful in this regard, or lose their tomatoes and potatoes.

And yes, Cornell has put out a Late Blight Alert and did quite a while ago based on the cold rainy weather we had in May and most of June.

Hope that helps.

Edited to add that Daconil is NOT a systemic anti-fungal, no systemic anything should be used with edibles, rather, it binds to the specific attachment sites on the upper leaf surface where the spores of Early Blight, Sepetoria Leaf Spot and LB bind, thus blocking those pathogens from binding. As with everything in biology, nothing is 100% in terms of preventing anything, so we do the best we can.

[Elliot]

Sounds like the heat wave has really taken a toll on your garden. I was listening to the weather and its like a bubble of heat over the whole country. This will split tomatoes because they do not do well with heat and ten sudden watering. Hope things get better for you.

[Dark Rumor]

Carolyn
Have you any opinions on Maneb or Mancozeb Fungicide?
My county extension agent said Maneb would help reduce the spread of the fungus we regularly experience in North Florida.

[carolyn137]

[QUOTE=carolyn137;224368]What is the specfic fungal disease that you fo Have in N FL?

Cornell and some other sites do suggest Maneb or Mancozeb as a back up for Daconil for the two most common fungal foliage diseases, Early Blight ( A. solani) as well as Septoria Leaf Spot.

And while I'd have to check it out, I do think that for those commercial places that have organic certification at one level or another, that Maneb orMancozeb are also suggested backups to Daconil for Late Blight ( P. infestans)/

Speaking for myself now, I know that Daconil DOES work by covering up the attachemsnt sites for EB and Septoria as well as LB,not perfect,but the best around for we home growers. so that's my choice in what we call here.... a NY minute.

I've spent a lot of time over the years researching Daconil via EXTOXNET and other unbiased sites,for there are many very organic sites out there that are very biased.

I also think that each person needs todo at least minmal research online for ANY product they want to use and make up their own mind about it

Edited to add that Cornell has an excellent site with recs for diseases using organic products but when you look at the data I don't think you'll be that impressed. I tis of use, again, for those foks certified organic and there are many levels of organic certification.

[Talon1189]

I have been reading your recent post on Daconil.....Carolyn137 ....I do respect your own opinion as you have taught me so much lately on a personal level about fungicides ...... Thank You!!! >>>>>>>Talon

[Dark Rumor]

Carolyn
Thanks for your insight.

[tam91]

I used Mancozeb some last year, when I had some Septoria that the Daconil didn't seem to control. I alternated them, and it did seem to work.

[Alberta]

I'm on Long Island and I'm not seeing any problems...YET!!

Alberta

[raindrops27]

Me either. Hoping for the best.

I probably will not spray.

Just to see how it goes. Most plants are looking fairly healthy a little septoria. I am just clipping infected leaves, and that is that. Earlier on(4 weeks) I sprayed once with daconil. Then, after a rain. I sprayed once with a diluted bleach solution. Then, I got tired of spraying. So, I stopped. Will see how it goes.

[Alberta]

I won't spray anything, I dealt with late blight a few years back, and I can tell you it was horrible, but i don't see anything like that on my plants at all. From what I remember that particular year we had so much rain, this year its been far and few in between. Last nights rains were really needed.
Alberta

[Alberta]

Last evening I really looked over all my tomato plants with a fine toothed comb so to speak...no sign of the dreaded LB.

Alberta