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derry n.h u.s.a.

Does anyone know how long this would take to work after being sprayed.3tbl spoons per 2 gallons sprayed top and bottoms of leafs,problem areas were minor,sprayed an hour before it down poured very hard,should i respray tomorrow?and does it kill mildew on contact or does it take a day or two to kill spores?Thanks in advance.John

8/3/2003 3:56:07 PM

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Spores are killed on contact. Only Copper & Mancozeb are capable of destroying dormant spores. Others can't. If that spray residue dried before the rain, then some control can be expected. If not, then a respray is in order.

But it's the spores that are *NOT* dormant that are the problem if symptoms are already visible. Contact fungicides are best protectants against fungal pathogens that have not yet penetrated the leaf cuticle & begun infection.

In other words, once infection has taken place & symptoms are present, a contact fungicide *combined* with a local penetrant (incorrectly called systemic) for at least the first 2 sprays is best. Once the sprays are in front of any new symptoms, straight up contacts are OK.

That said, there are a handful of bacterial & viral infections that can only be controlled with copper based fungicides. Though Powdery Mildew isn't one of them.

One way to help speed recovery is to follow up the "real fungicide" sprays with a shot of Safer Soap (consumer name) or M-Pede (commercial version). The "soap" helps remove the powder from the mildew and also provides both anti fungal & insect properties. Result should be visible in a few days.

Do provide extra attention to the undersides of leaves.

Steve

8/3/2003 4:40:34 PM

derry n.h u.s.a.

Steve,what is the best thing besides copper spray for "powdery mildew"i cant find (safer soap )anywhere,is daclinal good,the mildew is on the edge of two or three leafs here and their,i would like to keep it in check if possible,i used daclinal last year when the mildew was pretty bad,didnt seem to work so good!
I understand that copper and Mancozeb are great in preventing the mildew from showing up,but once its their what are some good knock out brands?

so if i combined a systemic fungicide and the copper and sprayed on the leafs that would be o.k could i mix Captions and copper,how much captions should i mix with two gallons??,Help:) thanks.John

8/4/2003 3:47:48 PM

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Copper plus a systemic like Nova/Eagle would be good. Topsin/T-Storm/3336 would work as a systemic too. Quadris/Heritage is my personal favorite. Compass probably has an ag/ partner too. I'll look later.

Even Summer Horticultural Oil mixed with Baking Soda does a good job as long as we stay on top of things timing-wise.

I've used Daconil + Eagle twice here this year. The rest were Mancozeb + Eagle. So far we're still clean. I should be rotating my systemic more so than the contact. But I'm too cheap to buy anything different & I ran out of Banner. At $365/Lb, I won't be getting any Heritage/Quadris any time soon unless one of the chemical reps is feeling generous. hint, hint ;-)

Safer Soap is also marketed to commercial applicators (it's NOT restricted) as M-Pede & should be available up your way. Punch your zip code into the store locator on our lousy website.

www.lesco.com

We have a store up your way somewhere.

Morse would have it too I suppose. Andgrow & UHS would. Agway used to but since the Chapter 11 thing. But they're my competitors so I shouldn't say nice things about them LOL.

Steve

Steve

8/4/2003 5:24:44 PM

derry n.h u.s.a.

Thanks steve :)John

8/4/2003 5:56:41 PM