CAPTAN 80 WDG How much per Gal


2 1/2 tsp. is .833 tbsp. so you are right in the happy range of what I posted 3/4 - 1 1/2 tbsp.

If you get good control (probably will) at that application level I’d stick with it, otherwise there is room for an increase.


It absolutely is Mike and sulfur is mentioned in combination with Captan on nearly every efficacy chart you’ll find, but there are also specific warnings concerning the combination on sulfur sensitive varieties like those I listed. I think I also included in above posts about when using sulfur in combination the recommendation was to apply the Captan at the lower or lowest rate. I suspect this is to avoid potential foliage burn which is why I mentioned it.

If I remember correctly I think the issue is addressed on the label under Compatability and Plant Safety



I mis-read your answer and then re-read it and the others’ carefully. Thanx.

Actually, part of the reason for my digital scale request was that I think that we all run into the situation where we see dosages based on different concentrations of the product we have on hand.

At those times we can easily calculate how much of volume or weight of our pruduct to use based on the known dosage of a different version of our pruduct.



I see. Yeah…and you’re right one of those would be handy.



I use a Nexus PS200 for a small digital scale. They are sort of pricey, but I bought it used through a police auction website fairly reasonable.

The reviews looked good and my scale has worked well for me for quite a few years.


I use a digital kitchen scale from Wallmart which cost about $15. It will weigh as small as .1 OZ or 1 gram


I have a digital scale that is only good under 20 grams. It may take some time to find the right containers to hold the right amounts by I will post the correct measurements of all the stuff I am spraying in case it helps anyone else and you can calculate the per gallon rate for each one of these products.

I got .940 g per 1/4 tsp for Captan 80WDG and .331 g per 1/4 tsp for Rally 40WSP. My Teaspoons will not be the same as your teaspoons unless we all own the same teaspoons. 3.76 grams per tsp of Captan 80 WDG and 1.324 grams per tsp of Rally 40WSP.

I came up with 1 1/2 teaspoons of Captan 80WDG per 1 gallon of water for Apples, converted from 5 lbs per 400 gallons of water.


I bought one of these misting sprayers this year. The throttle can be feathered when close to the plant, so hopefully I don’t blow off all the blossoms and leaves. :slight_smile: It seems to work well, but I’ve only sprayed trees that aren’t fully leafed out yet, and my trees are just starting to flower.
It cut my spraying time down considerably, and now with most of my trees being relatively small still, I can cover them with about half the amount of spray as I used to use with my wand sprayer.

My trees aren’t dripping using this mister, but they are definitely wet. I have an accurate scale and always weigh chemicals. With the first few sprays that I have done I have used the same concentration levels as I would with my wand.

I think with the wand sprayer I was wasting a lot of spray to make sure all parts were completely covered.

Should I increase the concentration of my spray using this misting sprayer? Any thoughts?


I’ve never used one of those and always use a handgun with normal spray at 200 PSI when trigger is pulled (spraying pressure). I was taught with any sprayer you spray until it just starts to drip- it’s a question on the test to get a permit. .

As far as using a mist sprayer for more concentrated mixes, I’ve read about it a bit but never done it so I’m not really competent to provide advice on it.


Alan, what kind of sprayer do you use? I’m tired of mickey mouse sprayers at 30 psi. I’ve been thinking of building my own with steam cleaning jets and a tank with compressed air.


I use a Rears estate sprayer with a 25 gallon stainless steel tank and 4HP Honda motor running the pump and a paddle wheel to keep the tank agitated. It’s perfect for a Surround program because the paddle wheel keeps it mixed while jet agitation fails to do so. Unfortunately the unit has gotten pretty pricey in recent years. Sometimes OESCO has a used on to sell.

Michael has rigged up a power washer to spray his rather extensive orchard- he uses some kind of aquarium pump to keep synthetic chemicals mixed. Probably covers his trees quicker than I could.


Are you talking about a gas powered “backpack” type mist blower.

You could flag off a portion of an acre, perhaps 1/10 or even 1/100 and spray water on the trees to see how many gallons will be required to spray that area of trees and make calculations for gallons per acre and figure the rate from that info.

Don’t spray water on open apple or pear tree blooms to calibrate your sprayer because it will accelerate FireBlight.


The recommendation for Captan 50 is 2 Tbs / Gal. Captan 50 is 50% captan and Captan 80 is 80% captan. So I figured you would need 30% less Captan 80 / Gal. for the same solution concentration. 2Tbs = 6 tsp so 4 tsp / gal.


Does Captan actually dissolve in the water or is the water just the vehicle to transport small pieces of Captan to the leaf?.