Pests, Diseases and Other Problems
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Subject: captan
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From
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Location
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Message
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Date Posted
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Brigitte |
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I pulled the withered up blossom off my week old fruit and there's a little white fuzz growing underneath it. I want to make a Captan paste to put on there. Is there a certain ratio to use, or just mix with water till it looks good?
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7/14/2003 9:37:39 AM
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jeff517 |
Ga.
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apply dry captan or sulfur.It will dry the fungus up for you.I have that problem with every attempt to set fruit.I must pull withered flower off 1-2 days after pollentation to keep this from happening.I'm guessing humidity causes this. J
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7/14/2003 11:08:02 AM
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Tremor |
Ctpumpkin@optonline.net
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Brigitte,
For stem cracks I've heard od making a pultice by mixing with enough water to make a pancake batter like paste or even heavier. I like the dust idea if the pumpkin is kept dry.
All of these practices result in illegal pesticide residues & are inconsistent with the legal labeled uses of the Captan 50WP that I have here. But that is the way some of the hitters do it.
There are many versions of Captan on the market & labeled uses of the different formulations probably vary.
For the record I've heard that the old Benomyl (Benlate, Tersan 1991, etc) made a pultice that better resisted cracking & flaking when dried. I don't know that this is true & hope never to need to find out. The way things are going though, I'll let every know soon enough. LOL
Be careful.
Steve
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7/14/2003 11:26:06 AM
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CEIS |
In the shade - PDX, OR
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Hey Steve - I've seen you warn us before on use of Sulfur dust.
Can you list some of the additional reasons/precautions why we should be extra careful with this chemical?
I think this would be good for EVERYONE to see.
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7/14/2003 7:49:44 PM
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Tremor |
Ctpumpkin@optonline.net
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Well what makes sulfur work is the rapid pH change in the environment the fungal pathogen needs to survive. Namely the leaf surface or cuticle. But sudden changes as this can have a very negative impact on the functionality of the leaf tissue & cuticle from the growing aspect (cell division) of the plant. ie burning.
What concerns me also with these Captan "pultice's" (sp?) is that the specimen label is the law. And these labels never recommend mixing at such high concentrations as these. When new pesticides are created, the plant tolerance levels are usually about 4x (minimum) as a general rule. But these pastes we see recommended are a LOT higher than 4X. That might be fine on a durable non-photosynthetic item as a fruit. But I wouldn't try it on foliage.
But why bother? There are many good fungicides that are legally labeled for fruit rots. Just use them instead & the rate is usually also appropriate for foliage diseases like Powdery mildew too. (Eagle or Nova perhaps mixed with Mancozeb comes to mind for many fruit rot diseases)
continued
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7/14/2003 10:15:42 PM
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Tremor |
Ctpumpkin@optonline.net
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With regards to all dusts in general is my concern for respiratory inhalation. Breathing in what amounts to a 50% straight technical grade Captan dust is really not a good thing to do. So wear a cartridge respirator if using this method outdoors. The wind is very likely to place the applicator at extreme risk. Likewise in a greenhouse where you can't even see the dust that is airborne around your head while you're working. Lungs are very sensitive & the interior tissues are as close to your blood as tissue get. Oxygen permeates these tissues quite well. Pesticides will too.
And don't count on those silly little nuicence particle masks (white with a rubber band) they sell at Home Depot & the hardware store. Those are for sanding dust & have no place in a pesticide laden atmosphere. Indeed they can make a bad situation even worse by trapping dust around the nostrils if not perfectly fitted (& they aren't perfectly fitted). The filter media is also not tight enough to stop dusts anyway. So don't use them.
A decent NIOSH approved Paint & Pesticide respirator is about $40.00. If working with dusts, just break down & buy one. Clean it when you're done with a damp rag. Let it air dry. Then store it in a freezer zip-loc bag. You'll find other uses for it too.
And always read the entire label before using anything.
Steve
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7/14/2003 10:15:52 PM
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Total Posts: 6 |
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