Rally, it’s my very strong opinion that you’ve chosen well. Actually, when it gets right down to it, the choices are really already made for a person like you ( I know this because I’m the same guy). Really, any serious home orchardist that has the space to apply it legally and safely (Phosmet).
Imidan is easily the best broad spectrum insecticide you will be able to get your hands on, and really, probably the best there is when we’re talking about PC. I’ve said it many times here, and not once has anyone disputed it, it is simply the cheapest, most useful (wide range of utility), packaged in usable sizes, and probably the most storable insecticide available. It is highly effective for all the insects you mentioned and many more. Like me, I think you are looking for a “one for all” type pesticide and Phosmet is as close as you are going to get. No insecticide is the best for everything…NONE, not even the $3600 dollar per gal. stuff.
Olpea correctly mentioned buffering…and Captan and Imidan both benefit exponentially from it as do many more, including some (perhaps many) of the synthetics I might add. This isn’t anything particular to Imidan or Captan and it’s NO BIG DEAL. Olpea is usually spot-on with his data, but from what I’ve read (a lot) I understand the longest activity is achieved with a ph of around 4.5 to 5.5 for both Phosmet and Captan. Use whatever acidifier you want, any vinegar, citric acid, lemon juice or whatever is just fine. Use cider vinegar if you like, it’s usually cheaper.
DO NOT think you have to be out there measuring and testing like a lab scientist to make it work…YOU DO NOT! All you have to do (you don’t even have to do it) is simply get the PH down…it residual activity is proven to be much longer if you do…and that’s what you want. Longer activity = cheaper and less spraying and better for the environment.
Jump on Ebay and buy some of that litmus paper that you do a PH test with. I paid, I think, 99 cents incl. shipping for a matchbook type deal with like 150 strips in it. It comes with a color chart and it’s apparently pretty accurate according to the crude tests I done. Don’t equate this to those junk soil test kits…these strips actually work. I checked my water, and then my mix once and got it set. I checked it months later and it was still identical. Pre-school girls could do this with exacting results.
Captan as a fungicide is akin to Imidan, in that it’s broad spectrum, and has but few weaknesses. It’s readily available in commercial strength, available in packages that, though large, are doable for a home orchardist. It’s also reported to be long storing, it’s inexpensive, super easy to mix (like easier than Kool-Aid) and tackles the vast majority of fungal issues…especially when we’re talking apples, but other stuff as well. Hell, it’s usable on just about anything…including your garden veggies if need be. It also does not suffer at all from resistance issues, in fact, not a single case of field resistance to Captan has ever been shown…not one.
Most (perhaps all) newer synthetics recommend spray combinations including a contact fungicide, there are many used, but that which is most principally used, I believe is Captan. If you kinda-sorta want to stay as organic as possible, consider a Captan-Sulfur combination. Sulfur is very cheap and it just so happens, compliments Captan quite well. Sulfur picks up a few of the stragglers that Captan misses, one is powdery mildew, of which Captan is effective for, but somewhat weak on. Sulfur is very strong in this regard. Oh…did I mention Captan is also one of the safer fungicides from a human health standpoint…it has a 0 day PHI. It also (contrary to popular opinion here), sticks around quite a long while.
Definitely, DO get the 80 WDG stuff, for whatever reason, it’s cheaper in terms of active ingredient / dollar ratio and mixes and sprays just wonderfully. As you mentioned too…no dust whatsoever. I worried about whether it would mix as well as the WP version…again, easier than Kool-Aid…no kidding.
Myclobutanil is too cheap to pass up. I once bought 6 bottles for $9.99 on ebay. You can only use it 2 times per season (some say 3 when combined with Captan) and I use it 2-3 times in combination.
I hope this helps, I spent a lot of hours studying efficacy charts and asking questions and pricing stuff. I got this one right. I’m pretty sure the quality of my produce can attest to that.
The combo you are considering will so dramatically outperform any OTC materials you can buy it’s not even funny.
Look at Keystone Pest Solutions when pricing both these products, they have for some time been the cheapest online and will ship to you without issue. Captan is no problem, even the 80% stuff, Imidan however is restricted. They shipped it to me no probs and it’s restricted here I think. They’ll still sell you Lorsban if you like.