Pesticide start up. Is this all I need?

Hey all,

So I have decided to go the non-organic route for my fruit trees, but apply a minimal spray approach. This is partly because my trees are located 2 hours away from me which will most likely prevent me from spraying weekly, and also partially because I am alright with a bit of damage on the apples. I have mainly semi dwarf on what I am assuming is M106. I do have a few standard and wild trees as well.

I am going to, eventually, have many different varietes, but as of now I KNOW I have goldrush, enterprise, Liberty, Pristine. I also have what appears to be a Mac type tree that my grandpa planted in the 60’s, as well as some sort of Red Delicious. This year I’ll be adding Wickson, Cox Orange Pippin, Arkansas Black, King David, and Hooples antique Golden.

My main pests are scab, PC, CM and Japanese Beetles. While I can’t really say that they are in great numbers, I do notice some damage. The biggest pest, IMO, is the japanese beetles.

After reading a bunch on here and other sites I think I should go with Captan 50W or Captan 80WDG. I’ve read that immunox is much better for CAR, but seeing as I don’t have much CAR I am electing to go with Captan. Is this logical? Or am I missing something?

Is there a reason to choose the either the Wettable powder or the WDG? All I can think is that the WDG is less dusty, and since I won’t be spraying on the per acre basis I like this. But if there is an advantage to one over the other please let me know.

Should I be mixing immunox (or another myclobutanil product) with Captan? Or is it not much of an issue since I don’t have CAR problems?

For insects I was planning on using Imidan 70W. This is pretty much just because of its wide availability and its cost.

I think I’ve got the basics covered, do you?

Captan should do fine for scab, and some of the summer diseases. As you know Captan has no activity against CAR.

Although I don’t use Imidan, it’s rated as a good all purpose insecticide. I have a couple of friends who use it with good effect. Around here it doesn’t control stink bug.

Overall it sounds like those choices should control the pests your after. You might include a sticker. Also consider using some type of acidifier to buffer your spray water. Imidan and Captan are very subject to alkaline hydrolysis.

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Olpea, I have in my spray notes to add half a cup of white vinegar per gallon as an acidifier when using Imidan, my city water PH is about 6.8, should white vinegar be added for all Captan sprays as well?

6.8 isn’t bad at all. You could add some vinegar to slow breakdown, but probably not necessary.

Most drinking water has a fairly high pH, so yours is somewhat surprising to me. Ours runs about 9.4.

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Is there a specific sticker and or pH adjuster that you would suggest? Is there a threshold for the pH?


For a sticker I currently use Nufilm. The Nufilm 17 has the extender, and the Nufilm P is just a sticker.

To adjust pH, I use citric acid. For my water, 2 oz/ per 100 gal. is about right. I wrote it one the can, but at the moment can’t remember what that brings the pH down to.

Generally about a 6 pH is a pretty good number, but it really depends on what you are spraying. For example, you wouldn’t want to acidify your water if you are spraying copper on the foliage, because it will increase the chance of burning the foliage. Something like Delegate performs best at a neutral (7.0) pH.

However many chemicals break down (at various rates) in alkaline water (Captan, Imidan/phosmet, glyphosate) so it’s a good practice to get the pH down in the acid range if possible.

Captan and Imidan are some of the worst to break down. You can google the chemical name and the words alkaline hydrolisis and lots of university stuff will come up, telling you fast the chemical breaks down at a given pH.


AS you may have seen, I just purchased captan and imidan both and was unaware of the need for lower ph water. Can I add vinegar to help? If so, any idea how much? I guess it would depend on the existing PH of my water (unknown to me) but I’d still like to get some idea of what you’d expect I would need to ad when using those products.



I looked it up on my can. I use 1 teaspoon per 16 gallons of water, which brings my pH down to 5.9.

You can use any acidifier I suppose (although I’m not sure I’d use muratic acid because of all the chlorine.

From canning recipes. 1/2 teaspoon citric acid equals 2 tablespoons of lemon juice which equals 4 tablespoons of 5% vinegar. Hope that helps.


Final question! :slight_smile:

I appreciate all of the help!

How long can one store, and use with reasonable results, Captan and Imidan? I found an old thread on here but I never really found a concrete answer. I’ve got roughly 15 trees, many of which are full standards. I’d rather just buy in bulk, but if I’ll have to use it in a 2 year time period I’ll probably just buy smaller sizes.


The reason you haven’t found a concrete answer is because there isn’t one. Manufacturers don’t stamp expiration dates on the chemicals, and the answers of how long pesticides last vary considerably. I’ve seen 2 years as a guideline.

Generally experts recommend looking for problems like separation of ingredients when it comes to liquids, or clumping when it comes to powders.

From what I’ve been able to gather, my opinion is that powders, or WDGs last pretty much forever if they haven’t been exposed to a lot of humidity, heat, or the outside environment. A few months ago I read about a fruit specialist who had some drums of oxytet, or streptomycin (I can’t remember which) that was something like 40 years old. He sent a sample off to a lab to test efficacy and it tested good.

Perfect! I’ve got some 5 gallon buckets and plenty of those activated charcoal desiccant bags to keep the inside of that bucket dry.

Thank you for the help! If I were able to just “run to the store” to get this stuff I’d be much less worried about it. But seeing as most of this will be ordered online, I like to make sure I get what I actually need.

Are there any other substitutes for Imidan that provide similar broad spectrum control? I was looking into cyhalothrin.

Another possible choice is imidacloprid.

A permethrin product like cyhalothrin has a reputation for creating mite problems which can be hard to control.

What would be the advantages of each?

I’m able to find slightly differen’t characteristics, but I really can’t tell what would be more beneficial specific types.

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.


Search for pesticide charts and include the name of at least one your interested in comparing,i,e Imidan.
You will find Imidan in just about every insecticide efficacy chart you will find.

Not really, for the reasons above. Cyhalothrin reportedly doesn’t store well, leads to mite outbreaks (it really does too), and has other issues like cost, storability, potential resistance issues etc.

FWIW, Imidacloprid is not a good choice at all imo., unless killing honey bees is your primary aim.

Holy moly that was a lot of info! I appreciate that!

Keystone’s website hasn’t worked for me in days.

Does anyone else have this problem?

what is the spray schedule for the described? And what protective gear for spraying? when can pets return to sprayed area