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Owensboro, Ky.

New grower from Western Kentucky who fought Powdery Mildew last year and pretty much lost. Looking for a way to stop it this year. I would appreciate any feed back concerning mycorrhizal fungi...how to...results...can it be used as a foliar spray? Also curious as to availability in smaller quanities. Natural Industries only sells in quanities large enough to treat 5000 3" plants. I am hooked on AG's but dont have room for 5000 plants. Thanks again for all your help. Peace Wayne

1/30/2005 6:27:44 AM

Menomonie, WI (mail@gr8pumpkin.net)

Mycorrhizae is for the roots. Applied at seedling stage or germination stage. Some also put it at new root nodes on the vines. For your powdery mildew I would recommend a systemic fungacide(Banner,Ridomil,Eagle,Quadris, plus a bunch of others). Then alternate with a contact fungicide every other week like daconil. The key to powdery mildew is prevention.

1/30/2005 9:24:13 AM

Simi valley, ca

pm will get you again unless you dont let leaves gro w on top of leaves, & do water in morning,,eventuly we will get it anyways. i used imunox pluss ,you must treet it the miniute you first see it. im trying banner max this yr expencive to buy 65$ a bottle but you dont use as often & supposed to be better ! rosemania.com

1/31/2005 2:33:20 AM

Appalachian Mtns.

Like Shannon said, *prevention* is the key. Start a "thought out and planned" fungicide program early, stick with it, and your season will go soooo much better.

1/31/2005 6:52:29 AM

Owensboro, Ky.

In a learning mode here...systemic means that it is taken in by the whole plant system...through the roots...roots and leaves? Does the mycorrhizae help to prevent fungi? By *prevention* do you mean to start applications of systemic and contact products before I see signs of PM? If so, how early should applications start? Thanks to all of you for your help. This site is great for us newb's. Also, still looking for a place to purchase micorrhizae in smaller quantities. Peace Wayne

1/31/2005 8:02:16 PM

Sheridan . NY

Vigor Cal and Vigor Phos -molasse- bakeing soda-- is quite a few thing that can help downie and powdery mildew
craig

1/31/2005 9:19:32 PM

Ctpumpkin@optonline.net

Mycorrhizae is a living fungus that when properly matched to it's host, lives in a symbiotic relationship with the hosts root system. think of it as an etension on the plants natural roots that helps it seek out nutrients (especially Phosphorus) & water & makes the host plant more efficient & thus better able to deal with stress.

Other soil microorganisms are better at preventing root diseases. Baccillus Subtilis helps roots avoid Fusarium root rot by innoculating the roots before the pathogenic fungi can get to them. This works on the idea of selling all the new houses in a subdivision to nice families before the riff-raff finds out about it & ruins the neighborhood. Elimination by exclusion if you will.

Other packaged soil bacteria work in other ways such as making the soil held nutrients more available to hungry roots thus decreasing the need for supplemental fertilzers.

But Powery Mildew has nothing to do with roots. The sporse are airborne & only land on & innoculate the undersides of the leaves. So this is where your attention needs to be.

Craigs idea is to do something similar on the leaves. By altering the surface of the leaf, we can make the area less hospitable for the Powdery Mildew causal pathogen (a spore). This can be as simple as spraying the leaf with baking soda & a spray oil which for a few days after application, makes the pH of the leaf surface incorrect for the development of the spores to infect the leaf. Milk can do the same thing when diluted (I THINK this rate is correct) to 10% with water.

Molasses not only alters the pH of the leaf, but also helps feed & stimulate the soil's naturally occurring beneficial bacteria at the same time. Thus Molasses should be applied to everything, leaves, stems, & soil.

If you can spray every few days, these "soft" applications can be quite effective.

continued

2/1/2005 12:33:57 AM

Ctpumpkin@optonline.net

M-Pede Insecticidal & Fungicidal Soap work this way too. M-Pede is the Professional version of the old Safer brand Soap that was sold in retail garden centers. I'm not sure that it isn't still, but Safer had some problems for a while & it couldn't be found. Soaps also have to be applied frequently though.

Conventional fungicides work in a similar fashion but last longer & generally control a broader range of diseases.

Contact fungicides last the longest & work by covering the leaf with a film that is toxic (fungistatic) to the developing spore (causal pathogen). Captan, Daconil, & Mancozeb are all contact fungicides. We still need to reapply these fungicides before they break down though. This because our plants literally ourgrow the application. Think of the protective barrier as a tissue paper glove. It is delicate & not elastic. So as a leaf grows & expands, the protective barrier doesn't. So the barrier layer is thinned & broken.

Systemic fungicides as we know them are not really "systemic". There is only one root absorbed fungicide that translocates throughout the treated plant. That fungicide is Aluminum Tris (Alliette or Prodigy are the trade names & they aren't sold at the retail level). But it doesn't work on Powdery Mildew at all. Alliette is used for Pythium & Phytophthora.

continued

2/1/2005 12:35:07 AM

Ctpumpkin@optonline.net

The systemic fungicides we often use are really mostly just "acropetal penetrants". This means they can penetrate between plant cells & move slightly upward from the point of application. These are useful if the disease has already started to infect but isn't yet out of control. Bayleton, Rubigan, Banner, Eagle/Nova, ProStar, & the older benzimidozol Topsin-M (also called T-Storm or 3336) are all local penetrant fungicides. We say these have "curative properties" which is an oxymoron. Usually of a disease is so advanced that we can see the symptoms with the nakes eye, it is already too far gone to be "cured". At this point the best we can hope to do is check the spread.

There. I'm in rare form tonight & this might be the best explaination of fungicides I ever wrote in one sitting. LOL.

Now if I could just learn to do it in less than 2000 characters I'd be doing something.

Steve

2/1/2005 12:35:19 AM

Ctpumpkin@optonline.net

I forgot to mention the newest class of fungicide. Strobilurins were derived from mushrooms that were discovered to be toxic to other mushrooms. This property was isolated & synthesized to create a whole raft of new fungicides that are softer on the environment & still able to kill pathogenic diseases. You'll see reference to Azoxystrobin, Trofloxystrobin, Boscolid, etc. These fungicides are very prone to resistance problems if applied more than a few times in a single growing season.

Since Powdery Mildew sprays start (here in CT) around July 1st & continue weekly all summer, then Strobilurin fungicides have to me rotated with either each other or preferably with other classes of fungicides to remain effective.

Your best & simplest bet would be to get some Daconil (contact) & Myclobutanil (Eagle or Triazicide systemic) & use these in a weekly rotation just prior to the usual outbreak for your area.

Check with a local experienced grower or cooperative extension agent for the best start date for your area.

2/1/2005 12:47:16 AM

Owensboro, Ky.

Steve, thanks for taking me to fungicide school...wonder if I can get any college credit...great lesson and thanks.
Peace Wayne

2/1/2005 6:50:41 AM

Garden State Pumpkins

Then start two weeks before you think ya have to. LOL

2/1/2005 6:53:42 AM