Spectracide 16-Ounce Immunox Multi-Purpose Fungicide Concentrate.
The active ingredient is myclobutanil.

My experience is that you have to be proactive with powdery mildew. Fungicides are not very effective at curing powdery mildew, but do work very well at preventing it.

Certain plants, like currants, gooseberries, strawberries, cucumbers, etc., are very prone to getting PM. If they have had it in the past, there is no reason to believe that they won't get it again in the future unless you spray BEFORE they get it.

I have shrubs that suffered through PM every year for many years. No more. My 1st Immunox spray is as the leaves are almost getting to full size, and before new growth. I spray every 2 weeks during the new growth period and then every 3 weeks after that. It works.

You can buy Immunox @ Amazon.com

This post was edited by northernmn on Wed, Jun 4, 14 at 7:06

Thanks a lot! Do you spray while blooming? Will it affect pollinators?

There are 2 types of Immunox. One contains an insecticide, and the other doesn't. The one mentioned, contains only the fungicide Myclobbutanil. Make sure that you get the one without an insecticide. It will not affect pollinators, and the fruit will still be safe for consumption.

The bottle that shows vegetables on the front label is the correct one to buy.

Thanks again, will do it!

It's going to be hard to treat having gone so far. I have red currants, I would try copper like Bonide liquid copper fungicide. Bonide Fungonil would probably work but not labled for use on currants. Copper is labled for use on currants, for mildew, so try it first.

What would be exact name for Copper fungicide? When I search just Copper , I ... well ... get copper - as a chemical element.

Another option with the same active ingredient as Bonide Fungonil is:
GARDENTECH -2115 DACONIL FUNGI CONC 16OZ

The active ingredient in both of these is Chlorothalonil.

But as Drew also mention, it is going to be very difficult to totally stop a fungus once it has started. These treatments will slow it down however. Next year, you will be able to be PM free.

Copper won't help much in managing PM.

If you want to go 'organic' you should start early in the season with sulfur applications. Powder sulfur tends to have a better preventive efficacy than wettable (sprayable) sulfur and vice versa with regards to their limited curative efficacy. Will not work when temps are cold. Another preventive (and somewhat curative) solution is light horticultural oils which will work at colder temps but should not be used when temps are high. Care must be taken not to apply sulfur within two-three weeks of applying oils, For both oil and sulfur applications test must be conducted first to determine if dosage is toxic to leaf tissue of the particular cultivar.

With regards to synthetic fungicides I would tend to shy away from anything not labelled for the specific use when applying to edibles and then closely adhere to the time of last application and other label instructions.
Nik

Fungonil or Gardentech can be used together with copper. That might be your best bet! I do mention a name. "Bonide liquid copper fungicide." I myself have on hand Bonide copper dust. The Fungonil product mentions on label that copper can be used with it.
I grow tomatoes and most growers like to use DACONIL, so it seems like a good product.
These are mostly preventattives so good luck. As mentioned get ahead of this next year, but for sure treat now!
Here is a link to the Bonide labels. Even if you use other products, this gives you good info on what to use for what. Check the copper labels for amount. The dust is nasty to work with, hard to measure out. But may be stronger than the liquid.
I use a tank sprayer to apply.

Here is a link that might be useful: bonide labels

Sulfur will not work at all as treatment. Yes, nice to use as a preventative, but completely useless once you have PM.
Gardentech says you can use DACONIL, so it is labled for use. So Fungonil, the same product can be used.
I'm all for organic, and copper is organic! But Daconil is an awesome product, not organic, but extremely useful and a must have if you ask me.
I would use daconil with copper in a tank sprayer. That is as hard as you can hit it.

This post was edited by Drew51 on Wed, Jun 4, 14 at 8:23

Copper won't help much in managing PM.

If you want to go 'organic' you should start early in the season with sulfur applications. Powder sulfur tends to have a better preventive efficacy than wettable (sprayable) sulfur and vice versa with regards to their limited curative efficacy. Will not work when temps are cold. Another preventive (and somewhat curative) solution is light horticultural oils which will work at colder temps but should not be used when temps are high. Care must be taken not to apply sulfur within two-three weeks of applying oils, For both oil and sulfur applications test must be conducted first to determine if dosage is toxic to leaf tissue of the particular cultivar.

With regards to synthetic fungicides I would tend to shy away from anything not labelled for the specific use when applying to edibles and then closely adhere to the time of last application and other label instructions.
Nik

Thanks a lot, everybody! I guess the strategy will be to suppress it as much as possible this year and to start early next year.

I wanted to add some black currants this year, but it's late now, so maybe next year. I have 4 reds, 2 whites, and 2 pinks, plus some cuttings rooted from them.
If this plant keeps getting PM, maybe try another cultivar.
I was looking at
Hilltop Baldwin
Minaj Smeriou
Titania

It is funny with black currants... They've been restricted in our area for a long time. Now, the local nursery sells them, but with very limited choice. And online stores will not send me what I want because of that "restriction" that is not restriction anymore, if they sell it locally. I have one other type I don't even have a name for - it has no problem at all, but it is not good in the taste and appearance - small berries are too bitter even for me, and I grew up in currant garden.