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Indiana

Ok I know this has been discussed before, But I'm getting ready to order some garden chemicals and I need to decide on a fungicide or two. I have only had problems with powdery mildew in the past. I want to use a preventative to avoid the problem all together (as much as possible)
What works Best?? Im willing to spens some $ to keep this in check!

Steve

1/4/2006 2:40:11 PM

Niagara County, NY

i have the same question steve, i am planning on doing a three week rotation of Daconil, Eagle and either Compass or Abound. Does anyone know if this sounds good. maybe i should mix some together? And what time of the season is best to start for prevention.

dan

1/4/2006 3:18:28 PM

Ctpumpkin@optonline.net

Eagle is the best DMI fungicide for Powdery Mildew.
However being a local penetrant (systemic) the over-use of Eagle *could* lead to resistance issues. Therefore the addition of a contact is required. Daconil is the only commonly available contact fungicide for Powdery Mildew. The other contact (Mancozeb) doesn't do PM.

Both Compass & Abound are strobilurin fungicides. Both are very good at controlling PM. But all strobis are VERY prone to resistance issues.

Dan's selection & rotation is just about as good as can be had if the goal is to work with 3 fungicides. Unless there is valid reason to do otherwise (other diseases) I recommend this rotation to all who will listen.

1/4/2006 5:58:31 PM

Indiana

Tremor What does DMI stand for?

1/4/2006 8:41:08 PM

Ctpumpkin@optonline.net

DMI = DeMethylation-Inhibitors

Most Sterol inhibitting fungicides fall into this class today.

Systemics don't *protect* from the outside in the traditional sense of a fungistaic protective cover. They penetrate the leaf cuticle to the point inside a leaf where disease mycellium is growing between & around cells. Most mycellium produces sterol during growth. (Sterol = Steroid based alcohol - sort of like cholesterol) If we can inject a sterol inhibitor at the point of infection, we can disrupt the mycellium development.

Thus if necrosis is already present, there is no translocation & we see poor results.

Like everything else in life, succesful use of DMI fungicides is a matter of timing.

1/4/2006 11:19:35 PM

sevierville, Tn

ok, so when is the best time?? Also does the use affect the fruit growth?? Seems i read that somewhere. Would we apply a systemic in july,august, 4 weeks after fruit set to be safe? Any thoughts or guides would be great. Thanks.

1/5/2006 10:45:03 PM

Ctpumpkin@optonline.net

Banner Maxx (Propiconizole) is capable of altering the flowering of some plants. There is nothing conclusive about its use on Cucurbits probably because no form of propiconizole is labeled for us on them.

Nova is labeled for use on cucurbits & has no flower recessive or growth regulating traits. Eagle is the same active ingredient (myclobutanil).

Start times vary by weather, region, spore counts, etc. The key is to start preventive sprays prior to the innoculation which is even earlier (2-3 weeks some years)than onset of symptoms.

If we set fruit on July 1st here in CT & then waited until August 1st to start spraying for PM we'd be in really big trouble.

1/6/2006 12:18:53 AM

virginia

Tremor.....are you saying daconil is the best to control powdery mildew,,,,,,Thanks,,,,,,greg

1/6/2006 1:59:26 PM

Ctpumpkin@optonline.net

No. Nova/Eagle is better but shouldn't be used exclusively due to the potential for resistance. So adding Daconil in rotation or as a combined tank mix is the best way to control PM.

Diseases have the potential to become altered to the very simple means by which systemic fungicides work.

Diseases have a very hard time developing resistance to contact fungicides like Daconil.

1/6/2006 8:54:43 PM

Garden State Pumpkins

Don't want to put words in anybodys mouth..but I think what he meant was that daconil was the best way to control PM ...if PM was already on the plant...If i read the posts correctly.. obviously prevention of the the infection was best but after it's there what will kill it....does that sound right?

1/6/2006 9:21:25 PM

Niagara County, NY

After powdery mildew is on the plant, you can not kill it , you can only control it.

1/6/2006 9:30:43 PM

Ctpumpkin@optonline.net

If PM is active the best way to manage it would be Nova/Manicure. No fungicide of any kind will erradicate it.

But once & for all, we have no business using JUST myclobutanil (or any other systemic) alone to treat it.

That mind set is why we can't control PM as effectively as we used to.

1/6/2006 11:58:50 PM

Coventry R.I.

hi tremor,it,s frank in r.i. tremor, i plan to use danicol, immunox, neem-oil with baking soda, is that good, and in that order, as far as starting would you say middle of july . thanks frank

1/7/2006 12:46:48 PM

What effect would Oxidate or Zero Tolerence have on existing PM?

1/7/2006 3:29:10 PM

Ontario, Canada.

For those chemically challenged growers Baking Soda, Milk, Teas, weak Bleach solutions & hydrogen peroxide are very good options.

This is not really a preventative measure more of a outbreak control measure. I have found and documented that you can mute unruly troublesome areas of PM very well. Spot applications of hydrogen peroxide or bleach solutions work well. Remember these are non selective so a cautious approach is required.

"PM is held in check on both plants..... In fact it has been a very minor concern to date on all of the LanTerra plants except the 695*. The 695* had some infected leaves last week which I quickly sprayed with the peroxide treatment." 2004>kahuna4 dairy.

http://www.bigpumpkins.com/MsgBoard/ViewThread.asp?b=3&p=129849

1/7/2006 4:30:36 PM

virginia

Thanks Tremor,,,,,,,,,greg

1/7/2006 6:20:17 PM

Ctpumpkin@optonline.net

Frank, I've never used Neem Oil for anything but Aphids & that was over 10 years ago. You need to watch the high temperatures.

If Powdery Mildew is the only disease a grower ever sees & they can make daily application, then you don't need fungicides at all.

Armicarb (baking soda), Molasses, M-Pede (aka Safer Soap or pelargonic acid), compost tea, real whole milk & I'm sure a raft of other items can be sprayed on plants every day to control PM.

Zero-Tol has worked wonders for some growers. But for every success story I've also heard of a grower who toasted his plants. I try to not recommend what I've never used & therefor don't wholly trust.

Alternative controls & home brews don't get widely tested by the commercial growing community. So much of what we hear is just that. Hear-say. This doesn't mean they don't work. They just aren't patentable & so no one throws money at testing.

When your career (= pay check, house, food on the table) depends on the results that people get doing things you tell them to do, then one tends to lean on personal experiences &/or close associations with professional researchers, edus & publications.

Commercial growers do NOT make daily application of irrigation water let alone pest control agents.

1/7/2006 7:26:33 PM

Norton, MA

Zero-Tol did nothing for me. My leaves were dry and crispy, even in the rain. AleX Noel.

1/7/2006 8:43:53 PM

Coventry R.I.

thanks tremor,kahuna4

1/8/2006 8:41:58 AM

Hereford England

UK cucurbit growers use potassaium bicarbonate with a little soap and keep crops clean - plenty water and often enough. Water itself damages the fungus. Trick is to damage fungus but not leaf. Also, we do not want ANY chemical residues - we need to know how much soft soap we can get away with safely when added to pot bicarb at 0.5 or 1% mixed in water; and water wants to be soft; I have tested 1% pot bicarb and 1% soft soap and got really good results on a weekly basis ....... but sprayed on HOPS not pumpkins. Anyone tried this mix yet?
If you don't care about resiudes then youcan't beat quinoxyfen plus potassium bicarb.
by the way sodium bicarb aint nowhere so good.

1/18/2006 6:13:47 PM

ENGLAND

PGhops
Great to see another UK Grower visiting this Website.

Regards
Mike

1/19/2006 4:45:28 AM