Using chemical spray has a very simple rule. If it says you can do it on the label, you can, if it does not mention it, you can not. Using any pesticide, requires following the directions on the label. Al

Premixing is a normal part of spraying fruit trees and you can be sure if there was a problem with the combination you mention it would have been well documented here as these are common ingrediants for growers using this forum.

I commonly mix those three chemicals with the exception of triazide, but I've mixed other pyrethroids with Cap and Im (myclobutanil).

The main issue you are likely to encounter is captan anywhere near oil. You can't mix the two and shouldn't even spray them within about 14 days of each other.

Labels are very cautious about this for liability reasons, recommending you try a sample branch and come back later, but in the real world damage as a result of mixing incompatible chemicals that are well known is not common.

I should mention that what Calistoga says is not necessarily true, IMO. Chemical companies are responsible to the safety of their customers based primarily on the ingredients in the formula. You mix at your own risk from a legal perspective and they cannot be aware of all compatibility issues.

Yes it's very common to tank mix pesticides. In many cases, it's recommended by universities.

Captan and an SI fungicide like (myclobutanil) Immunox is an excellent example. SI fungicides are prone to develop resistance issues in commercial orchards. Mixing a fungicide with multiple modes of action (i.e. Captan) pretty much eliminates resistance issues.

Another reason for tank mixing are than for large acreages, it takes a significant amount of time and fuel to cover the acreage. There would be no reason to duplicate the use of those resources by making multiple passes with different compounds. Additionally, multiple passes could wash off crop protectants from the previous pass.

There are university charts that show the compatibility of various pesticides. Generally, incompatibility shows up as one pesticide causing another to precipitate out in the spray tank. Although rare (but still happens) the mixture can cause foliage burn to the plant tissues.

I'm 99% sure you'd be fine mixing Captan, Immunox, and Triazicide. Just make sure you follow the label rates.

All that said, why do you want to mix Captan and Immunox? Most backyard growers use either one or the other per application.

As I spray Immunox and Triazicide quite a bit, I knew that was safe. And, I've never seen anything to indicate adding Captan would be harmful. But, my question is the same as Olpea's... If not to prevent resistance, why do you need both Immunox and Captan fungicides at once? -Glenn

I want to apply both Immunox + Captan for all my trees: peach, apple and plum trees (maybe I'll add it to pear tree too). Yes, I could probably remove Immunox from the peach trees...but I rather error on the wrong side.

Should I only add Immunox to Apple trees, without Captan ? I'm in NJ.

If spraying peaches then I would not spray both fungicides.

If you are spraying apples then I assume you gong for rot and ceder rust. I've mixed Immunox and Triazicide. I've mixed Captan and Triazicide but not both fungicides and Triazicide. I noticed on apples VT recommends spraying a cover mix of
.0 tbsp Immunox 1.55%EC
plus
2.0 tbsp Captan 50W
plus
2.5 fl oz M-Pede
or
2 tbsp Thionex 50W
plus
2 fl oz permethrin 2.5%
or
2 tbsp esfenvalerate 0.425%
or
1.5 tsp Confirm T/O

Always different ways to skin a cat

I wouldn't use Captan for a few trees but I do worry about resistance enough to want the added and much tougher fungus lock of Captan. By lock, I mean the difficulty of fungus developing resistance. Once that happens with Immunox, which is an easy lock to pick, you've lost the most useful fungicide for apples.

Also if you've had a lot of apple scab issues the addition of Captan gives you added protection when you get rain in between applications, because it relocates to newly grown leaves (washes from one point to another). This is also one thing that probably makes it more dangerous in terms of human exposure.

I agree also that Captan is probably better for brown rot than Immunox but that is after scab and CAR season.