North American Fruit Explorers mailing list at ibiblio

[<dmnorton@royaloakfarmorchard.com>]

Captan should not be tank-mixed with sulfur, lime, or oil or any other alkaline materials and should not be applied within 7 to 10 days of a sulfur, lime, or oil application.  These materials will reduce the fungicidal activity of the Captan. This information is on the label and the label should always be read completely before using the product. 

 

For your other question, if you are asking can you reduce the rate(s) of either the sulfur or a more specific mode-of-action fungicide such besides Captan in the tank-mix with the thinking that the sum of components will equal an effective single application of one or the other? I would not do this. I would use the full rate of the fungicide, and at least a moderate label rate of the particular sulfur product. Sulfur is cheap; there's not much economic sense in applying a sub-lethal dose.

 

You can trust the recommended label rates as they are given for a reason.  You usually have a range to work with such as Captan 80WDG which has a recommended rate of 2.5 lbs. to 5 lbs. per acre.  If you are going to tank mix it with another fungicide, you can use half the rate, i.e. 2.5 lbs. per acre instead of 5 lbs., but not less than the recommended range.  These ranges are given to help reduce resistance and to make sure no more than the recommended rate is used per season.  For Captan 80WDG the max per season is 40 lbs. per acre per season no matter what rate you use.

 

Hope this helps!

 

Dennis Norton

Royal Oak Farm Orchard
http://www.royaloakfarmorchard.com
http://www.theorchardkeeper.blogspot.com
http://www.revivalhymn.com

----- Original Message -----

From: Mark Dorogi

To: 'North American Fruit Explorers'

Sent: Tuesday, May 06, 2008 8:27 PM

Subject: [NAFEX] Captan/Sulfur

I sprayed captan on my apples last night; they are in full bloom.  But, I was low on captan, so I mixed it at about 50% the label rate.  Then, I used sulfur when I ran out. This caused a few questions to pop into my mind.

 

What would happen if I used the standard “home orchard spray” at 50% of the recommended strength?   In other words, if I assume I’d get near 100% control using it per the label instructions, would I expect to get 0% control at 50% strength?   Would there be any difference for fungicides vs insecticides?   I’m wondering if anyone has ever evaluated this.  I’m a trusting person, but on the other hand, I have no reason to trust that the label application rates are at the minimum acceptable level.

 

Also, is there any harm in mixing captan and sulfur?  I rinsed my sprayer when I switched from captan to sulfur, but the trees are close together and there were some branches that got some of both.

 

 

Mark