Early blight prevention with copper fungicide

[wildcat62]

I'm new to the use of copper fungicide. So this may be a stupid question. It looks like this stuff prevents the blight but will it kill/suppress it if it is already present. I recently noticed what I believe to be early blight & after discussion with the local coop I pulled all foliage that appeared to be diseased & anything that came close to contacting the ground. Sprayed the copper from top to bottom heavily. We got another rain about 24 hours after the application. I go out this morning and looks like a few more leaves are affected. I realize I'll have to spray again today after the sun goes down as it's sunny hot/humid already this morning. Will the copper kill the spores are will it only prevent new foliage from succumbing? What a battle.... I'm not giving up.... The plants do have a heavy fruit set & I can't wait to bite into them. Any advice would be greatly appreciated???

[Dewayne mater]

There is a study out there (posted by someone in Tville) saying that a mix of Copper and Mancozeb is significantly more effective as a fungicide than Copper alone. It has a thick, somewhat sticky consistency that dries out leaving you tomatoes covered in a yucky film. However, it washes off easily in water and from what I can tell, using the two combined is a good tool. That said, this is a rather scary story about one of the ingredients in mancozeb that I just found. http://www.ncbi.nlm.nih.gov/pubmed/12558996 Good luck.

Dewayne Mater

[carolyn137]

Originally Posted by wildcat62

I'm new to the use of copper fungicide. So this may be a stupid question. It looks like this stuff prevents the blight but will it kill/suppress it if it is already present. I recently noticed what I believe to be early blight & after discussion with the local coop I pulled all foliage that appeared to be diseased & anything that came close to contacting the ground. Sprayed the copper from top to bottom heavily. We got another rain about 24 hours after the application. I go out this morning and looks like a few more leaves are affected. I realize I'll have to spray again today after the sun goes down as it's sunny hot/humid already this morning. Will the copper kill the spores are will it only prevent new foliage from succumbing? What a battle.... I'm not giving up.... The plants do have a heavy fruit set & I can't wait to bite into them. Any advice would be greatly appreciated???

If you are sure that it's Early Blight, then yes, it's one of the four common foliage diseases.

Copper will not kill the spores and cannot cure it,I don't remember what its action is, but it is used for both bacterial and fungal foliage diseases,so not specifically for fungal ones.

I know what the mode of action of Daconil is,which is a synthetic which has a lower toxicity than does Rotenone, which is approved as being organic by all organic certifying agencies I know of, and Daconil works by covering the attachment sites on the upper leafsurface so that the spores cannot attach.

Best used as a preventive, since with all such products there can always be new infections of all the common foliage diseases since they are spread by wind and rain.

On the upside, there are some years when there aren't any problems,it just depends how far from you there are the same infectious bad guys, or gals, as it were. And it also depends on the weather in any one season as well, asto rain,etc.

Prevention is key since there are no cures.

Carolyn

[wildcat62]

Thanks for the info. This website is a virtual encyclopedia of information. I've grown tomatoes for years and other than last year can't remember a significant problem with disease. Last year was absolutely terrible for myself and our whole area. Pretty much wiped everybody out. Thought I'd try to stay ahead od it this year. And it's not real bad yet. (Fingers crossed as I head toward my garden with the sprayer). I did move my garden from our old spot to a section of the farm that hadn't been plowed in 40 years at least. I thought that would definitely help. Overall it's the best garden I've ever had in my life. Really cranking out the squash, zucchini, broccoli, kale & cucumbers right now. Green beans, peppers, cabbage & melons all look terrific. Lots of work=lots of good eating. Thanks again, Mark