Captan 80 WDG

[Gundogblue]

Hi all,
First off this is my first post on this forum,and I’m real glad to be a member. First a little about myself. I have 4 yrs experience growing fruit trees, I have 3 apple trees,6 peach trees, and 3 apricot trees. So I don’t have a lot of experience in fact I got my first crop of peaches last yr! So I have a whole lot to learn. Right now I’m spraying my fruit trees with Eagle 20 every 14 days, but I read it’s a good idea to alternate my fungal sprays to avoid fungal resistance. So I just purchased a bag of Captan 80 WDG. I have a 6 gallon battery powered sprayer and Cordova the makers of Eagle 20 told me to use 1 tsp per gal of water, but I’m not sure how much of the Captan I should use per gal of water! I reached out to the maker of the Captan I bought but they told me they can’t legally tell me how much Captan I should use per gallon of water. So If any one knows the answer to my question I would greatly appreciate the answer.
Thanks Much,
Paul

[mamuang]

Most spray amount info is in the Guide Category.

Spray amounts guide.

The Captan they listed is 50% WD, the 80 WDG you bought.

You would need to do the math from the label info of your product

[Gundogblue]

I’m not sure how to do the math, but I came up with 1.8 ounces which would be 3.6 table spoons of Captan 80 WDG per gallon of water, but that seems awfully high to me??

[Robert]

I’ve been using 3 spoons per gal, but they are heaping ones.

[mroot]

@Gundogblue

The rate is about one tablespoon per gallon for Captan 80.

Take a look at this post and the linked thread in the post for more information.

Low-Impact Spray Schedule (2019 Edition)

@Robert Take a look this thread- It looks like 1 tablespoon/gallon would be correct but read thru the thread carefully and make your own judgement. The rate for Captan 50 (50% concentration) is 1 1/2 tablespoons per gallon if you adjust this rate for Captan 80 (80% concentration) you get 0.94 tablespoons per gallon which is approximately the 1 tablespoons per gallon recommended in the thread.

Also make sure your spray water is acidic. If you water is basic the Captan will break down before the spray is on the trees. To adjust your spray to make it acidic look at this post for how to adjust it.

Low-Impact Spray Schedule (2019 Edition)

With Captan you need to make sure the spray water is acidic. At a pH of 8 half the Captan is destroyed in 10 minutes. A pH of 5 is ideal with 5-7 being ok if your going to spray right after you mix the Captan into the water. You can use vinegar or citric acid to lower the pH. I use citric acid which is found with canning supplies in retail stores. I use a 1/4 teaspoon of citric acid in 2 gallons of spray water. The amount needed will vary with the pH of your tap water. Buy some pH paper and use …

[Gundogblue]

Wow thanks SOOOO MUCH, for all this great info, I really really do appreciate it and your time. I would never have guessed the ph of the water would affect the chemicals used!!!
Thanks Much,
Paul

[mroot]

Your Welcome

The need for acidic spray water should be on the label but it isn’t. I think it’s because Captan is an old fungicide and labeling requirements were less comprehensive in the past. Luckily someone on the forum pointed it out to me that pH could be a problem.

[mamuang]

Don’t forget to the these two categories: Guides and Reference. Tons of very useful info.

[Robert]

I found the actual rates from the company somewhere(thinking it came with the captan itself). It runs 1-31/2 spoons per gallon based on what you are spraying. I’m using the max because I want the max.

[mroot]

I would be interested in seeing your source of information. Do you have a copy of the label you used to come up with the concentration per gallon you’re using?

Based on the Captan 50 rate (1 1/2 tablespoons/gallon) and adjusting for the higher concentration of Captan 80 80% vs 50% of the Captan 50 the rate for Captan 80 should be 1 tablespoon per gallon. Also the thread I linked to above ultimately came to the conclusion that the rate should be 1 tablespoon per gallon.

[Robert]

@Robert

It runs 1-31/2 spoons per gallon based on what you are spraying.

I’ll try to find it. There is a chart with fruit types and amounts per gallon per fruit type.The stone fruits were more or less the max mix and I take it a little over that. Most everything else was less than 3 spoons per gallon.

[Bradybb]

I have been using Southern AG Captan,at 49.25%. Like Robert pointed out,it depends on what the crop is,Nectarines(Brown Rot and Scab)-1.5-2.58 level Tablespoons per gallon of water,while Strawberries(Botrytis,gray mold,Leaf Spot)-4-8 level Tablespoons.

[mroot]

@Bradybb Is your formulation a powder or granules?

[Robert]

Here is what I bought and they give the spoons in the spec section a little. Not the chart though. Stone fruits are 9 tea spoons which is 3 table spoons.

• Fruit and Nut Crops: 1.25-5 pounds per acre (1.5-9 teaspoons per gallon)
• Ornamentals and Non-Food uses: 0.6-2.5 pounds per 100 gallons (1.6-12 tablespoons per gallon)
  https://www.keystonepestsolutions.com/captan-fungicide-80wdg-6-25-pounds-423

[AndySmith]

I use Captan 80 WDG and I use 4 teaspoons per gallon (for apple and pear).

[Bradybb]

@mroot

Is your formulation a powder or granules?

It’s a powder.

[ribs1]

This doesn’t seem to make sense. WDG stands for water dispersible granule. I don’t think Captan 80wdg is a powder. Also, I don’t think Eagle is labeled for fruit trees.

[Robert]

I think they are just small granules that look like powder.

[Bradybb]

Mine doesn’t have WDG written on the label.

[Gundogblue]

Eagle 20 is labeled for fruit trees, and it’s very good. I want to thank you all for the great info, I learned a lot. When I do my Captan 80 WDG I’m gonna use a tablespoon per gallon of water, AND make sure the ph of the spray water is between 5-6.
Thanks Much,
Paul