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Old June 30, 2010   #20
carolyn137
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Join Date: Jan 2006
Location: Upstate NY, zone 4b/5a
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I thought it might be helpful to post two links here, both have to do with organic products and Late Blight and both conclude that copper is about the only thing that has shown any effect at all, although limited:

http://plantclinic.cornell.edu/FactS...MGT%202010.doc

http://www.nysaes.cornell.edu/pp/res...olanaceous.php

Tom, I know you best of the folks who have posted here so I'll direct my remarks to you but they pertain to the others who have also posted in this thread.

First, let's respect the right of each person to chose how they want to approach Late Blight as long as that person knows what they should about various products and their efficacies, which in some cases here I think some wrong, or should I say misleading information has been given.

That doesn't mean you should take what I say as gospel, but it does mean that I hope some of you would consider some perhaps alternative views.

Second, I don't care one whit if a product is synthetic or organic b'c both can have side effects. Rotenone, for example, is approved by every organic certifying agency I know of, NOFA is that agency where I live, and Rotenone has been shown to have greater toxicity in some ways than does Daconil ( which I'll refer to as Daconil so I don't have to type out Chlorothalonil each time)

What's important to me, be it a synthetic or organic product, is what the toxicity is or mnight be for humans, pets, insects, etc, well, the environment in general.

I started researching Daconil maybe 15 years ago. I'ts the most used ant-fungal in the world and has been for I think about 30 years now, and more is known about it than any other fungicide and many other products in general.

Because I have a scientific background I tend to approach questions of toxicity with that view and my conclusion many years ago was that Daconil was the best antifungal for the common fungal foliage diseases of Early Blight ( A. solani) and Septoria Leaf Spot and I used it for that purpose until about 10 years ago when I moved to a new location, amd there weren't the problems here with those two pathogens so at that time I decided to use organic fertilizers, well, that's about all I could do except for the occasional Colorado Potato Beetles for which the specific strain of BT worked well.

That was then , this is now.

For me and many others LB was never a major problem until last year and where I am in NYS was hit hard. I knew about it early in the Spring so had a decision to make, and an important one at that. Do I risk loosing ALL of my tomatoes, and those who know me know I now grow only varieties new to all or most, so it was an important decision to make.

I read the bulletins, I consulted the excellent information given out by Cornell and I decided to go ahead last year and spray with Daconil alternating with copper.

There were folks in my area who had LB infections. About 10 min away a field of about 1000 plants being grown for a farm market stand went down ASAP.

I had no LB here at all.

My point is that when faced with a possible dire situation and wanting to grow the special varieties I was growing I made the decision to use Daconil and copper and as I said previously I had reseached Daconil myself and felt comfortable using it based on the data I had read.

This year so far I'm only using Daconil but no copper but will add the copper if I start to see bacterial foliage infections.

I apologize, just a bit, for this post being so long, but I hope by posting what I did I at least brought another perspective to this issue and I hope the two links above will be helpful to some of you.
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