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West Chazy,N.Y.

I have not seen any post on this ,so I thought I would ask. At what point in the pumpkin plant stage or life does someone start the powdery mildew spray,to prevent the powdery mildew?

6/26/2006 8:01:55 PM

Www.extremepumpkinstore.com

I started my fungicide program 3 weeks ago.

6/26/2006 8:16:27 PM

Mocksville, NC

Before it starts, hot humid night here, before i mow the lawn, because its in the air, and all over your yard, and before scatterd thunder showers follwed by times of sunlight, during those days the night are perfect condition for pm i use a weatherstick kind, and watch for time i last sprayed, and insecticides too,( thats what i do)May not be the best, but works for me

6/26/2006 9:24:01 PM

Rhode Island

Do a fungicide spray AFTER rain storms...the rain brings in all the crap thats in the air...rotating fungicides is an advantage but not necessary....insecticides on your regular basis should work fine or if the bastards decide to invade before your ready.....grow-em BIG

6/26/2006 10:16:42 PM

Mocksville, NC

JRB, Is right if you live in NY, In the south different ball game 2 days rain you will be trying to cure it, not prevent it, yu'll see it under the leafs. The insecticides we have to use, are pretty hot, so we have to be very careful. Lost all in 02 because of my mistakes, but i'm learning , and having fun, not much fun in 02 though.

6/26/2006 10:58:52 PM

Montoursville, PA

The fungicides should always be several different ones in rotation, to prevent resistance build up. The so called best and newest indicate never more than two times, in a row, in the same patch along with or within a three or four product rotation.

6/26/2006 11:09:55 PM

[email protected]

Doc speaks the truth. Succes with Strobilurins has led to serious resistance issues.

Here's the deal in simplified short form:

Contact fungicides only protect but they do it well. There are only 4 of any consequence. Because of their multi-site mode of action resistance potential is very low.

1.) Chlorothalonil (Daconil, Bravo, etc)
2.) Mancozeb (Dithane, Petathlon, Fore, etc)
3.) Vinclozolin (Curalan, Touche & Vorlan)
4.) Iprodione (Chipco 26019, 26GT, etc)

Strobilurin fungicide (Class 11) are often called "reduced risk" due to their very low mammalian toxicity & minimal environmental impact. These also have very good protective properties. "Strobis" are so prone to resistance issues that we must rotate them with other MOA's & none should ever be used more than 2-3 times in a single growing season. Once disease activity is noted, all strobilurin use should cease completely. I'm not going to name them all but the list includes:

Quadris/Heritage/Abound/Amistar (azoxystrobin)
Flint/Compass/Gem (trifloxystrobin)
Cygnus/Sovran (kresoxim methyl)
Insignia/Pristine/Headline (pyraclostrobin)
Reason (fenamidone)

After Powdery Mildew is evident we must realy on systemic fungicides to check it. These include the sterol inhibitor fungicides. Eagle/Nova is the best of this group. This is a large group but the ones that are most common are:

Rubigan (fenarimol)
Banner (Propiconazole)
Eagle/Nova/Rally (myclobutanil)
Bayleton (triadimefon)
etc, etc, etc

The old benomidizole group used to include benomyl (Benlate/Tersan/etc) but is now mostly just:

Cleary's 3336/Topsin/etc (Thiophanate-methyl)

TM only works on diseases that are already active especially with respect to vascular disorders.

6/27/2006 12:23:39 AM

[email protected]

Given the options I'd like to see folks doing something like this for Powdery Mildew:

Downy Mildew folks should also use Daconil early but adding Mancozeb into the mix is strongly recommended.

1.) Daconil alone
2.) Compass or Heritage alone
3.) Daconil plus Heritage
4.) Mancozeb alone
5.) Daconil plus Compass
5.) Eagle or Nova alone (if symptoms have appeared)
6.) Daconil plus Eagle
7.) Just Eagle

etc

The trend here is to never use strobis twice in a row, try to add a contact with strobis whenever possible & abandon strobi use entirely once symptoms appear. Getting as many different fungicides into the mix as possible is a good move (within reason).

6/27/2006 12:31:22 AM

West Chazy,N.Y.

Thanks for the response guys It realy helps alot!

6/27/2006 5:14:46 AM