I recently bought a backpack sprayer- a Osatu star 16 green. Up till now I have been only using an inexpensive 2 gallon pump up sprayer the same kind you use to kill weeds. I want to use the new backpack sprayer with Captan 50 powder.
My question is do you typically pre-mix the Captan in a bucket and then add it to the sprayer or just add the Captan to the sprayer directly and mix it in the sprayer tank? The Osatu star 16 green is a manual piston pump type sprayer similar to the Jatco sprayers. The manual that came with the sprayer doesn’t offer any guidance. I know with Surround you would want to pre-mix in a bucket and then filter the liquid thru a screen to remove large chunks but that seems to be overkill for Captan which is a pretty fine powder.
If you guys have experience with Captan in piston pump sprayers I would really like to hear from you.
I have found that Captan 50 powder is very hard to dissolve (or maybe mine is old). To me, dissolving it before pouring it in the tank is a must. I would even go further to suggest that mixing Captan in a bucket with a bit of acidic water to make slurry first before adding the rest of acidic water.
I am used to mixing Surround powder with water in a bucket. That is a piece of cake compared to mixing Captan 50 powder.
I used Captan 80 WDG in a backpack sprayer with no problems. The wettable granules dissolve well and don’t cause any problems. Just something to consider if you experience issues with the Captan 50.
My sprayer is similar and I usually mix the powder in a gallon size plastic milk jug,using warm water.It seems to work fine.There is also a filter basket,at the tank’s top.
I use 4 tsp / gal. There was a recent thread that discussed the rate per gallon : Captan 80 WDG - General Fruit Growing - Growing Fruit
I think the consensus was for 1 Tbs / gal, so my rate is slightly higher, but I did calculate the rate based upon the higher concentration of Captan in 80 WDG as compared to the rate used for the Captan 50.
I saw that thread but after a few people commented on it, it got confusing. I think I will go with 1 TBSP because I use Captan with Indar to prevent fungicide resistance, in addition to fighting diseases.