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Ontario

What do You use to control powdery mildew?
I have been using benomyl systemic fungicide wettable powder.
It is to be sprayed on when it first appears and repeat ever 7 to 14 days.
Two of my plants have it , but the other 2 have nothing.

8/6/2004 8:01:20 PM

Www.extremepumpkinstore.com

Immunox Plus, took care of it for now, has not spread.

8/6/2004 8:12:28 PM

[email protected]

I'll us any good DMI systemic plus a contact. It is wise to never use either more than twice in a row. Personally we use either Mancozeb+Eagle or Daconil+Banner in rotation. I have had cause to drench Prodigy Signature ((Aliette is the same thing) or Aluminum Tris) this year as I suspected a vascular system disorder.

DMI Systemics (sic): Banner, Bayleton, Eagle/Nova, Rubigan, ProStar, etc. These are really just local pnetrants & do not really translocate at all. They're acropetal penetrants meaning the move slightly downward from the point of contact but never upward. These do behave like contacts for a short time after application in that they slightly envelope the plant for a spell.

Contacts: Mancozeb/Manzate or Chlorothalonil (Daconil, etc) are the only two. These offer the best preventive properties & tend to last longer than any of the other fungicide classes. They function by forming a barrier on leaf surfaces that is toxic to fungal pathogens that try to colonize the area. We have had better versions of contacts such as Vinclozolin (from BASF) but they are gone for political reasons only. Science played no hand in their demise.

Benomyl & Thiophanate-methyl are Benzomidal fungicides that exhibit systemic (sic) or local penetration. This class is prone to resistance issues & should be combined with contacts as often as possible. May be used as a drench for Rhizoctonia or Fusarium root disoreder.

Strobilurins: Like Quadris/Heritage, Flint/Compass, Pristine, etc. are also local penetrants. These are also likely to exhibit resistance issues & MUST be used in rotation. We are only seeing the tip of an iceburg right now as this class of fungicide is going to be huge.

Copper based fungicides (NuCop, Kocide, etc) are also more or less systemic. These pose the greatest risk to applicators. They're demise could come soon.

continued

8/6/2004 10:02:59 PM

[email protected]

Aliette/Prodigy Signature is the only true systemic fungicide that exists. Useful, or should I say labeled, primarily for Phtyphthora but makes a great tank mix partner with mancozeb/Maneb/Manzate.

Banol, Subdue, Truban, Banrot, Terrazole, etc are again primarily used to treat Phytophthora or Pythium root rots. These are also used as drenches is root issues arise.

So there we have it. There are a lot of tools out there because we often have many jobs that need doing. Some folks prefer one type to another probably for reasons of luck or convenience only. By that I mean we tend to stick with what has worked best for us even though the grower down the road may have gotten just as lucky with our least favorite fungicide and he now swears by it. LOL

There are no bad fungicide when it comes to controlling diseases. Only bad reputations caused by people who have timed an application improperly or selected a mode of action that was not appropriate for the situation.

Hope this helps.

Steve

8/6/2004 10:03:08 PM

No Place Special

Of the above mentioned, which can be bought at a local garden store?

8/7/2004 1:01:21 AM

[email protected]

Mike,

I list only the Pro names of stuff because that's what they're called when first introduced to market. Consumer use & labeling/packaging takes years to happen.

Not even one of the Pro materials I named is restricted use. So find a place that sells it & you're in.

Retail garden centers do sell Mancozeb & Chlorothalonil in consumer packaging. Eagle/Nova (Myclobutanil) is the active igredient in Immunox (I THINK). Since Bayer owns Bayleton, it might also be found on retail shelves. I don't know.

So yes, you can find some of these in small pack.

8/7/2004 8:05:23 AM

Commack, NY

Steve, what is it about the Copper based fungicides that pose the greatest risk? what can we do to minimize the risk?

8/7/2004 8:25:18 AM

[email protected]

To minimize fungicide related health risks, don't use Copper based fungicides. Nu-Cop & Kocide are the only 2 fungicides that growers use that carry DANGER labels. In order of mammalian toxicity:

CAUTION is least toxic.
WARNING is more toxic.
DANDER is most toxic.

8/7/2004 11:23:30 PM

Monrovia, CA

Has anyone been using the old baking soda and dish detergent with any success or is there no comparison to the above products?

8/8/2004 12:05:18 AM

Ontario, Canada.

Compost tea & molasses really inhits PM from gaining an advantage in your patches. You still need to use the fungicides at the first sign of disease and a preventative dose of systemic. This can reduce your need for the exspensive contacts.

8/8/2004 12:41:43 AM

Tipp City, Ohio

Steve,

I did not know that "DANDER" was toxic....lol

8/8/2004 11:07:56 AM

Monrovia, CA

Do you just buy the supermarket variety of molasses or is there a cheaper source?

8/8/2004 11:11:41 AM

Whidbey Island

5 gallons (will last a few years!) or commercial grade molasses cost me 12 bucks at the local feed store.

8/8/2004 2:13:01 PM

Wv

has anyone had success with daconil

8/8/2004 10:11:25 PM

Halifax, Nova Scotia

Can anyone tell me why the surface of a number of leaves that I applied a mixture of baking soda and dish soap to turned brown? Can't see anymore mildew, but I'm thinking the mildew was doing less damage then I just did.

8/9/2004 9:32:54 AM

Halifax, Nova Scotia

I mixed a couple of drops of soap and a spoonfull of baqking soda in a spray bottle. Apparently that was too much.

8/9/2004 7:59:47 PM