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Powdery Mildew Help!

 
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Hi, folks.

Adam here in Northern Minnesota.

Seems I have powdery mildew on my young apple trees.  In terms of an organic application, what do folks find to be effective?  I found a really great study conducted by Washington State Univ:

http://treefruit.wsu.edu/article/powdery-mildew-management-in-conventional-and-organic-apple-orchards/

It indicates that sulfur is a widely used/effective method of control.  It looks like a lot of bacterial applications can be used as well.  Has anyone used either/both of these?  Alternatively, the study references a number of conventional, non-organic applications (fenbuconazole and myclobutanil being some of the most widely used) but I'm reluctant to dive into the world of chemical fungicides if it can be avoided.

Thanks for your time!  Any info will be helpful as I hope to order something in the next day or two..
 
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Bacillus subtillus (sp?) Works well  but requires multiple applications, especially if there is a bad infestation. There are sulphur and copper based fungicides that work well too, but I can't vouch for their ecogrooviness.
If I want to get rid of a.powdery mildew infestation I would get some potassium bicarbonate and mix it with water until I had.water with a pH of 10+. I would spray that heavily on the affected plant twice, 3 days apart. And then i would start spraying b. Subtillus once a week/10 days for a month or so. Some brands of subtillus that ive used are Serenade and Companion (I'm personally a bigger fan of Companion but I think Serenade is available at like home depot type places nationwide)
 
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A really good treatment for powdery mildew is: 1 gal water, 1 T dish soap, 1 T baking soda.

Since you want to spray young trees you might need to make a double or triple batch.

I have read not to store it though I don't know why.
 
s. lowe
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Anne's response reminds me that there are lots of products out there that I hear work well that are a combination of [ vegetable oil (usually corn or soy) + soap + isopropyl + (sometimes) essential oil (I have seen vanillin, oregano, rosemary) ] I don't know the ratios but I bet you could find recipes online
 
Adam Dettman
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s. lowe wrote:Some brands of subtillus that ive used are Serenade and Companion (I'm personally a bigger fan of Companion but I think Serenade is available at like home depot type places nationwide)



Thanks!  I found a jug of Companion online.. gonna order it later today.  I will likely supplement with a sulfur spray + home-brewed compost tea.  Thanks again for your input.. eager to put a number of methods to work on the problem!
 
Anne Miller
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The source I got the recipe from included a tablespoon of oil.  I didn't see a need for it so I left it out.

The only thing that I have had with powdery mildew was a sage bush. It worked fine without the oil.

With trees, I can see why the oil was in the recipe.
 
s. lowe
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Adam Dettman wrote:

s. lowe wrote:Some brands of subtillus that ive used are Serenade and Companion (I'm personally a bigger fan of Companion but I think Serenade is available at like home depot type places nationwide)



Thanks!  I found a jug of Companion online.. gonna order it later today.  I will likely supplement with a sulfur spray + home-brewed compost tea.  Thanks again for your input.. eager to put a number of methods to work on the problem!



I make a tea of worm castings + bokashi + insect frass [4:1:1] aerated for 4-12 hours and it seems to do wonders for keeping immune function high and preventing molds generally. For a 20 gallon batch each "part" would be about a 1/2 cup
 
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Greenhouse of the Future ebook - now free for a while
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