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litchfieldgardener

late tomato blight again

13 years ago

Within the past week my field of 16 thriving heirloom tomato plants has been struck by late tomato blight. It looks as bad as the terrible summer of 2009.

Wondering how widespread the infection is, in this area (which would include CT, southern MA, eastern NY).

As we all know, the problem is virtually untreatable once it has set in. But as a last desperate effort to save some of the crop (which was massive before this event), I'm going to try spraying a chemical not previously known to me: Ridomil Gold. Has anyone had experience with this fungicide? (It's expensive!)

Comments (23)

  • 13 years ago

    I'll try to find that Cornell site which keeps track of outbreaks of Late Blight in all the states surrounding NYS but yes, my memory says NYS, MA, DE, NJ, MD, CT, PA and I can't remember the rest.

    Or you can Google it yourself, just enter something like-----Cornell Late Blight.

    And Late Blight, as well as Early Blight, two different pathogens, can occur early OR late in the season.

    I didn't think Ridomil was available to those without a Pest Certification, but that varies from state to state as well. There's Tatoo and others that commercial farmers use, but no matter what it is those preps cannot cure an infection once started, they're used only as preventatives by most farmers.

    For any new infections, which are always possible b'c they're transmitted via air and in rain, I'd still stick with Daconil if it were me, and it is me who asked Freda this AM, she does my gardening for me since I can't being in this walker, if she would please spray again with Fung-O Nil, which is Bonide's Daconil at 29.6% active ingredient, so needs to be diluted according to the info on the label.

    Carolyn

  • 13 years ago

    Very sorry to hear that. As a victim of the 2009 blight, I can relate. Not much solace to you, but at least the weather should cooperate for the next week or so with sunny and dry conditions, and it shouldn't spread too fast.

  • 13 years ago

    I have been hit in Central NY, I have been pulling infected spots for two days now and am going to try a couple teaspoons of baking soda, and couple teaspoons of veg oil and a few drops of dish detergent mixed into a gallon of water and sprayed onto the leaves. If it slows it down I can deal. If not, Looks like I'll be pulling plants by next week.

    CH

  • 13 years ago

    I did Google Cornell Late blight 2012 and found that they are no longer doing weekly updates and referred folks to the link below which is a national Late Blight ( P. infestans) update.

    Hope that helps.

    Carolyn

    Here is a link that might be useful: 2012 Late Blight Update

  • 13 years ago

    There are a couple of sites online that track outbreaks of late blight (aka LB), but none that I've seen go past early July. Of course this fungus can be an overnight sensation, so meaningful tracking needs to be within a few days. My guess is that it has already become pretty ubiquitous in Eastern U.S. this year, but the reports are very slow to trickle in. Unfortunately most home gardeners are not aware of the early signs, and assume it's a watering or nutritional problem.

    No question that our recent rainy/cloudy/cool weather in this region has a lot to do with the sudden appearance. As I said earlier, I don't have much hope of changing anything at this late date. But I'm very interested in the positive reports re Ridomil (mentioned in various govt. and university ag sites). Even if not for this year, I intend to make it a major part of my preventive spraying program for next year. Ridomil, like many of the strobilurin fungicides, is regulated on a state-by-state basis, but can be purchased by mail in CT. (BTY: I never spray fungicides or insecticides in my garden unless absolutely necessary, and then very selectively.)

  • 13 years ago

    There are a couple of sites online that track outbreaks of late blight (aka LB), but none that I've seen go past early July. Of course this fungus can be an overnight sensation, so meaningful tracking needs to be within a few days. My guess is that it has already become pretty ubiquitous in Eastern U.S. this year, but the reports are very slow to trickle in. Unfortunately most home gardeners are not aware of the early signs, and assume it's a watering or nutritional problem.

    No question that our recent rainy/cloudy/cool weather in this region has a lot to do with the sudden appearance. As I said earlier, I don't have much hope of changing anything at this late date. But I'm very interested in the positive reports re Ridomil (mentioned in various govt. and university ag sites). Even if not for this year, I intend to make it a major part of my preventive spraying program for next year. Ridomil, like many of the strobilurin fungicides, is regulated on a state-by-state basis, but can be purchased by mail in CT. (BTY: I never spray fungicides or insecticides in my garden unless absolutely necessary, and then very selectively.)

  • 13 years ago

    Please don't pass your disease to the east. I am in Middlesex County, CT and don't have any signs of early or late blight yet. I use Ortho Max Disease Control (which contains Daconil) regularly when the plants are young. Sounds like I'd better give them another shot.
    John A

  • 13 years ago

    Just an update. My plants are still pretty healthy. Out of 48 plants I have not had to pull any, and I have removed approx 10-30 infected plant parts per day with the vast majority being single leaf lesions. There were two infected fruit and a handful of stems in there as well.

    After spraying with the homeade spray, It has rained once and that was monday night. Due to being super busy, I have not gone out to inspect since monday morning. I feared what I would find this morning when I went out. To my surprise.... ONE late blight lesion. Thats it, after a rain and a 2 days of no inspection or lesion plucking, there was one solitary leaf (that I could find) with a late blight lesion on it.

    Perhaps we shouldn't just immediately pull late blight plants after all? I have already gone a week after first discovery and have gotten many breakers off the plants in that time.

    CH

  • 13 years ago

    Got a link for these late blight trackers?

  • 13 years ago

    It almost looks as if my garden is completely blight free.

    I have had 3 fruit with the blight spots and a bunch of the leaves and some stems. But upon recent inspections, the few remaining spots I find are dry and brown and just fall off when I try to grab them. But they are not looking like active lesions, the just look and feel like completely dry dead tissue.

    It's not even spreading out anymore. Also I sprayed the solution on my squash and pumpkins with powdery mildew and that has all dried up and died off. Is this little cheap spray really that effective? Has anyone else tried this method? Can I get some other testers to try this please?

    CH

  • 13 years ago

    May not be late blight.

  • 13 years ago

    Grey Mold looks similar to Late Blight, but it won't kill the plants real quick like Late Blight does. Grey Mold happens when it is warm and humid (it is often seen in greenhouses) where as Late Blight occurs with cool damp weather.
    Remy

    Here is a link that might be useful: Google Images for Grey Mold

  • 13 years ago

    I've got LB here on Long Island, Suffolk County, again. Although its affecting almost all my tomatoes, the worst hit was black cherry for some reason. I just can't figure it out anymore.

    Alberta

  • 13 years ago

    I'm also in Suffolk with LB. I have some tomatoes coming, but what do I need to do for next year?
    Any over winter treatment?

  • 13 years ago

    Fritz
    one thing is to clean up all the debris from the affected plants, and get rid of it, sadly it can't be composted as I normally do. Keep an eye on the tomatoes coming in, if they have the lesions or blackened skin then its definitly LB...again get rid of them, if the tomatoes do not appear affected they should be ok to eat. The only over winter treatment I could suggest is to add compost to your beds and not to grow tomatoes in the same spot next season. I am not into all the spraying that others do, :)

    Alberta

  • 13 years ago

    Another update, LB is back, and seems a little more than before. I haven't sprayed nor removed any infected lesions in a few days due to being too busy, and it appears I might be paying the price for it soon. Will try to get to it tonight but I do have some important errands to run after work. Boo.

    One question, if I harvest a fruit and it has a little blight lesion, will that lesion grow on the fruit? Will it spread to other fruit stored next to it?

    CH

  • 13 years ago

    Unfortunately I am in the same sad situation, late blight again.

    Yes, the lesion will grow on the fruit as it ripens. I discard all fruit that has even the smallest lesions. I haven't found that the lesions spread to nearby fruit, probably because there is no wind indoors to spread the spores.

    Your best bet is to harvest all the fruit that has even a slight tinge of ripening and bring them inside to ripen. Some may already have spores that haven't developed into lesions yet. If there are spores, the lesions will develop as the fruit ripens,so keep a close eye on them and cull those out.

    I learned the hard way that leaving the fruit on affected plants outside where spores are blowing around means the fruit will eventually get lesions and become inedible. Bringing them in to ripen will give you a good chance of getting some harvest. I have a 4 shelf storage unit loaded up with ripening fruit right now and have only lost a few to lesions.

  • 13 years ago

    so as far as next year and not growing, our "garden" is 4x8 with only 3 toms usually. I guess that means no toms there next year, eh? Phooey!

  • 13 years ago

    Late blight needs live tissue to survive. You can plant there again next year.

  • 13 years ago

    LB hit me here in the Northeast corner; removed all my tomato plants & potato foliage last week and bagged it up.

  • 13 years ago

    I saw a small touch of it last week in southern CT. Got rid of the affected leaves and so for it hasn't returned.
    John A

  • 13 years ago

    I think I've got it on the border of Hartford/Litchfield counties. The Glacier tomatoes are about finished anyway, will pull them this weekend, but I see stem lesions on the Bloody Butchers next to them. Do the spots scrape off with a fingernail, or do they go deeper into the tissue? Not seeing sporulation. Might not be LB since I can scrape the discoloration off pretty easily, but the garden is looking pretty bad after 2" of rain on Sat and a couple of nights below 45.

    The only plants really hanging in there are the Sudduth BWs, and since there aren't that many left of any size, harvest will pretty much be over next week. BKs are about done for (lots of dying leaves though no stem lesions), Speckled Romans are falling off the plants (though plants don't look too bad, these are supposed to be Ind. but I wonder since there don't seem to be any new fruit forming), cherry tom stems look really bad (exactly like the picture on usablight website) and aren't scraping off as easily so I'll probably be pulling everything but BB this weekend.

    My second planting in another area is looking good, but I really should have suckered and strung them up (vertical string) better, lots of green tomatoes of all varieties, again maybe no time for BWs to ripen but might get some Bloody Butchers and Black Krims over the next month if the weather cooperates.

    And the few potato plants still alive look great!

    Been awful lately for fungal diseases though - I pulled almost all my pumpkins last weekend b/c of downy mildew (the cukes went long ago), the zukes are on their last legs so will be pulling those as well this w/e, but my second planting of yellow straightneck and my gourds are getting it, I don't even know if I'll get anything off of them.

    Time to just pull all the annuals I guess and start putting the perennials (berries) to bed for the winter...

  • 13 years ago

    I started pulling all my plants this weekend - found fruit lesions on Bloody Butchers. Stems on cherries are almost all dark brown/purple (not small splotches) but I'm confused - split one open and no brown inside, looks healthy green/whitevascular tissue. Still pulling them today, but isn't LB a vascular disease?

    Also some suckers and leaf clusters are dying (brown, dessicated), but I have some leaf clusters and fruit clusters that look healthy and green, even have flowers! Is this just because I'm catching it early (regardless of how bad the stems look)? I thought the dry leaves were just from the dry (pre-Isaac) weather, so many green leaves and fruit still on the plants last week I didn't notice the stems of the cherries when I picked them earlier in the week.