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San Diego, Ca.

I have discovered the same problem that CindyB3 has.....Powdery mildew! I have caught it very early with only about a half dozen spots total on just 3 leaves. I will be spraying Daconil when it cools down this evening.
I was wondering how all the rest of you fight off this dreaded plague. I have heard about using baking soda, does this really work???
I also heard about using bleach so I took a cotton ball and soaked it with bleach and applied it right to the spots of mildew. The result....I burned a hole in the leaf but I think I probably killed the mildew too. That might have been a little to agressive...LOL.

8/7/2003 10:31:52 PM

Ottawa Valley, Ont, Canada.

i put some garden sulphur on some rot i found the other day and it looks a little better. its starting to dry up.
good luck.

8/9/2003 7:13:31 PM

Ctpumpkin@optonline.net

While I've never tried it, Bleach doesn't sound like a very good idea.

1 Tbsp Baking Soda = 2.5 Tbsp of Superior Summer Oil will ta=ke care of it if you have an aversion to conventional fungicides. Works well too.

Combining a contact & a systemic fungicide will also halt it.

The damaged parts will stay damaged either way. So if it's spreading fast, act faster.

8/9/2003 8:55:16 PM

Sequim, WA

eco erase, a type of jojoba oil that will eradicate powdery mildew. I know rose growers who use it and swear by it. I use a preventive treatment with Neem because I'm already using it to kill the aphids.

8/10/2003 12:55:48 AM

San Diego, Ca.

Thank you all for the help. Tremor, I don't have a problem with using conventional fungicides...I guess I just jumped sideways after spotting signs of the mildew. I've lost other plants in the past (squash and the like) so I wanted to make sure I knocked it out right away.I probably wasn't vigilant enough before using Daconil but now my pumpkin is at stake! Is once every 7 days going to clear it up using daconil? Temps are around 90-95 in the day and down to 65 at night. Its only been moderately humid here, around 50% humidity.
What is a systemic fungicide exactely? what would be the name of one of these types of fungicides? I'm a first timer with AG's so I need to get up to speed. thanks.

8/10/2003 2:49:11 AM

Ctpumpkin@optonline.net

Your Daconil should remain as part of the weekly program. But add a systemic fungicide to it for better curative results.

As far as systemics go there aren't a lot of options for retail consumers. But I was snooping around last week & found that there were 3 half way decent product offerings which I ranked below.
__________________________________________________________
#1 goes to Spectracide who offers 2 products that only contain the active ingredient "Myclobutanil" which is the same as Eagle (& Nova). Kudos to Spectracide for bringing some real deal modern chemistry to the consumer! Watch these guys though. They use the "Immunox" name in several "bundled packages" that also contain such things as contact insecticdes &/or miticides. Fine if that's what you're after. But in this case we aren't. So read the label carefully before buying.

Immunox Systemic Fungicide &
Spectracide Turf & Ornamental Fungicide
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#2 goes to Ortho (even though the rest of their line up is antiquated beyond belief) for their use of propiconazole (same as Banner or Spectator) in one of their Turf & Ornamental products. There may be more from Ortho, but this is the only one I found.

Ortho Lawn Disease Control Ready Spray

No mention of fruits or vegetables on the label so some quick math will be in order to figure out the rate though.
_________________________________________________________

#3 goes to Bonide for their old school offering of a trusted Benzomidal class of fungicide (Benomyl was a benzomidal fungicide). They choose to offer Thiophanate-methyl in a consumer package. This stuff works too.

Bonide "Bonomyl" (cute) Turf & Ornamental Fungicide
_________________________________________________________

Always read & follow all label instructions. Be safe.

Steve

8/10/2003 6:57:11 AM

Caceres, mid west of Spain

Powdery mildew is the most common an insidious pest here. Contact fungicides aren't appropriate for me as far as many hours irrigation everyday will take them out of the leaves, so I have to keep on sistemics. I've used several products with no definitely good results. The worst thing is, like Steve has said, that the damaged leaves still damaged, so the grey spots don't dissapear, and you don't really now if the fungicide is working. I've tested Quadris (azoxistrobina) and prodimenol 25LE (triadimenol 25%), last year I used carbendazima. I am not happy with them. I liked the use of seaweed on the leaves in the evening after irrigation time, but now I cut its use in order to keep the plants free from any kind of fertilizers to prevent splits.
A friend of mine has recommend me Topas, which is very effective in wineyards and labeled for cucurbitaceas as well, it contains tetraconazol and is pretty expensive. I'll give it a try; don't want my plants to slow down too early. Also will use the oil and baking soda treatment.

Don

8/10/2003 7:32:39 AM

New Bremen, Ohio

How much will a small amount of powdery mildew play in the growth rate of your fruit?

8/10/2003 8:18:38 PM

San Diego, Ca.

Thanks Tremor for helping out. I actually had a bottle of Immunox in my hand while at the store the other day but the salesman told me Daconil would solve all the problem. Its good to be able to talk to someone like you who obviously know his stuff.
So if I understand you right I need to check the bottle to see that it contains the ingredient "Myclobutanil" Right?
Sorry for so many questions :-)

8/10/2003 8:43:44 PM

Ctpumpkin@optonline.net

That is correct & think nothing of it. I also do this for a living, so it's not any worse for me than someone asking you about your day. Plus I typed all that last week. All I did was copy & paste. hehehe

The guy with the Daconil was sort of correct. Provided the disease wasn't already active. Daconil is very good at preventing PM. That's why we want it to stay in your mix.

If a small amount of PM was suddenly checked by a sharp drop in humdity & temperature (or fungicides), then the affected leaves would stop declining after several days. (remember that infested foliage takes a few days to display symptoms). The remaining foliage would contribute to fruit developement. Unchecked, PM will slowly destroy all or most of the leaves. No leaves - no growth. It's a question of percent foliage versus ideal area of foliage for conditions present formula that I'm not privy to. Though somewhere I've seen some ideal estimates for number of leaves &/or estimated square footage of foliage required to keep a big one growing. I suppose it's all about conditions & goals.

Best wishes to all for speedy corrections & big honkin' pumpkins!

Steve

8/10/2003 9:43:18 PM

Ctpumpkin@optonline.net

To comment on something Don/Carlos said. The spots won't go away. If fungicides are working, what we see is nothing. That's kind of hard to accept sometimes. But the other option is rather worse.

Steve

8/10/2003 9:47:17 PM