Propiconazole - monterey fungi fighter

Hi all,

Monterey Fungi Fighter is 1.55% Propiconazole.

I have found “generic” propiconazole online at 14.3% and 41% concentration. At $13.00 to $17.00 a pint for the 1.55% the other concentrates are so much cheaper.

Am I missing something or is MFF somehow different?

Any ideas?

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I’m interested in what others answer on this one. I bought some recently for the first time and got the 1.55%, as it was the only one labeled for fruit. I got it for $17.95 at Treehelp (online), which was quite a bit less than some of the other online sources.

@alan @olpea @Appleseed70

Maybe one of you, or someone else who is knowledgeable about pesticide formulations have an answer or educated guess on this one. I tried looking it up, too, and also found that the more concentrated generic ones were only listed for lawn type uses.

I do see that Topaz, at 41.8% propiconazole, is listed for use on a wide variety of crops. It has a rate of 4 oz./acre on stone fruits and strawberries, and 6 oz/acre on berries.

Below are links to lists showing the BRAND names for various fungicides


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I very much doubt it.

This is typical of fungicides and insecticides too, those intended for lawn applications or non-edibles often seem to be higher in concentration and cheaper too.
I very much suspect the reason for this is that they need to work and the required safety threshold is much lower for things not intended for human consumption. Both the United States and Canada have established MRL’s (maximum residue limits) for fungicides and insecticides and propiconazole is no exception. The concentration level and perhaps the carrier agents obviously play into the amount of residues remaining on the fruit at harvest.
There is certainly no problem with the efficacy of these products on fruit trees, after all propiconazole is propiconazole and the product will absolutely be effective. They are even listed for non-bearing fruit trees in nurseries and for ornamental crabs etc.

So then the question is “Are they safe to use on edibles”?

One area where they could differ would be in the carrier agents or binders that are a part of the non-active ingedients. I only mention this because it is a possibility, but I very much doubt there would be a problem. The concentration levels however most likely would impact MRL’s so for OTC formulations regulatory concerns will come into play. Lawn and ornamental applications would want a strong rainfast binder whereas that may not be possible in formulations for edibles due to regulatory constraints governing MRL’s etc.

I personally would use these products, but I’d do it cautiously by reducing the concentration to a bit more than MFF’s and I probably wouldn’t use it anywhere near harvest. By that, I mean I would extend the PHI to at least double that of MFF. I would do that just so that I felt reasonably comfortable with the safety of using it.
That’s what I would do, I’m not suggesting anybody else do it or that it’s a good idea.
I’d most likely just spray Captan which is cheaper and can easily be had in commercial formulations. I realize though that every fungicide offers specific targeted advantages over others and for some propiconazole may be the ticket.

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The PHI for MFF is up to day of harvest.

Ok…and that’s at MFF’s mix ratio of a product @ 1.55% with approved residue etc.

So then, maybe I’d wait something like a week or two. That’s all I’m saying.

Just to be on the safe side.

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The Canadian residue limit is 4 ppm on stone fruits. So, my goal would be stay under that as best possible using the highly accurate method of guesstimation.

Thanks for chiming in, Jeff. I know you’re better at following this type of information than I am.

Each of these chems must have a registration abstract of some sort that lists the carrier agent as well. Wonder where one would find it. I am sure its out there .

QUALI-PRO BRAND 14.3% -LABEL-> [ ], available at [ Professional Arborist Supplies and Tree Climbing Gear ]

AT $44.95 a quart will give me as much active ingredient as 18+ MFF pint bottles at $17.00 each. That is equivalent to $2.45 a pint of 1.55% strength.

I am checking to see IF it is labeled for fruit trees.

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Th PHI should not be affected by using a 14.3 % product.

My thought is to keep the concentration actually applied to the tree the same as if I was using the 1.55% MFF mix by diluting. MFF is a good product and its 1.55% mix works. I don’t have a problem with that.

But since 14.3 is 9.2 times 1.55, I should use just about 1/9 as much of the 14.3% QUALI-PRO per gallon as I would if it was the 1.55% MFF.

Am I right?


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In the past I’ve used Bumper, which is the commercial propiconazole for fruit trees. It’s 41.8% active ingredient.

I think part of the reason some formulations are labeled for fruit crops and some aren’t is because some manufacturers have sought expanded labeling (of fruit crops) for their formulation and some haven’t. It’s very expensive to seek additional labeling. If the chemical manufacturer can’t sell enough product to the target market, they can’t get a monetary return on the extra cost of expanded labeling.

An example of this at one time Captan 80 WDG had a one day re-entry interval on tree fruits, while Captan 50 had a 3 day REI. As I understood it, at the time the manufacturer of Captan 80 sought and was approved for the 1 day REI, while the manufacturers of Captan 50 had not. (Now I believe Captan 50 also has and 1 day REI.)

I see this type of thing quite often. Even on herbicides, as far as I know only Stinger (clopyralid) is approved for use in orchards. However, there are many generic clopyralid formulations for lawns, which are not labeled for orchards. The difference is that Dow Agro sought and obtained the labeling for orchards whereas the other manufacturers did not.

Another reason some products are labeled for certain crops, where other virtually identical products are not, has to do with restricted use. For example, commercial grade permethrin for use with termites can be purchased by anyone. However, a permethrin labeled for fruit trees, requires an applicator’s license (Restricted Use Pesticide). My guess is that the EPA allows John Q Public to use the permethrin around his foundation, but doesn’t want him using the concentrated product on his trees. If John Public decides not to follow the directions and dumps 10X the amount of product around his foundation, it’s not as big a deal as if he uses 10X the amount on his fruit trees. 10X may seem like an exaggeration, but with a concentrate, it’s not at all out of the question for someone who has no experience using concentrates. It takes an extremely small amount of product in a pump up sprayer. Someone who is “winging it” could easily dump 10X the amount required in a small sprayer. For that reason I think the EPA reserves the “Restricted Use” products for food crops (at least with all the pryrethroids class insecticides). Plus I’ve noticed the “Restricted Use” permethrin is an emulsifiable concentrate (oil based), where the unrestricted termite permethrin is water based. My guess is that the water based permethrin breaks down faster, but that’s just a guess.


Thank you Olpea and Jeff for taking the time to sort this out and explain it to the rest of us.

I would agree 100%, IF we knew that there was no carrier or additive difference. As far as registration statement of the inactive ingredients, I agree there should be something out there. I would think the carrier etc may be important information for medical facilities in the case of accidental poisoning. On the other hand, the manufacturers may consider their formulations proprietary so perhaps they aren’t required to disclose them. I dunno.

Heck Mike, I’d do it. I’m liking the Captan so far, but I wouldn’t mind having some of this stuff also. BTW, I think I’ve seen this same thing with myclobutanil, though there are products available listed for fruit that aren’t very expensive.

Mike, I looked through your link and the Quali-Pro stuff looks like it’s listed for non-fruiting fruit trees only, unless I missed it somewhere else in the literature.

Does anyone know the correct pronunciation for this stuff…I can think of numerous possible pronounciations?





I don’t know if pesticides are like pharmaceuticals where the generic versions aren’t actually based on original recipe and are instead the result of reverse engineering of the new manufacturer and are almost but not necessarily identical to the original. I recently learned this of generic drugs and was a bit floored by it.

As far as the original question, I don’t think you should be surprised that a manufacturer scalps their customers if they can get away with it. On-line price comparisons do open up a world of bargains for the person willing to search.

Adjuvants of different formulas could be a concern if the product is not labeled for edibles. I’m not sure how you can get around that because the producer does not have to reveal specific adjuvants- only “active” ingredients.




Inert/inactive ingredients in pesticides are required to be registered w/ the EPA and do have tolerances.

I think it would surprise most people how much research the EPA requires for the registration of a pesticide. The active ingredients, inactive ingredients, as well as breakdown components are tested on the pests, crops, environment, non-target species, rats, etc, as well as tested with other pesticides. That’s why it costs tens of millions of dollars to get a pesticide registered.

That said, again I think the reason many pesticides are labeled for fruit crops while some are labeled only for lawns is because some companies simply don’t want to pursue the labeling because of the cost. Compared to row crops and lawns, fruit crops are considered a specialty crop, which doesn’t generate enough sales volume of pesticides for pesticide manufacturers to pursue labeling for fruits. As an example, peach acreage is not even 1/2 of 1% of the amount of land devoted to corn production in the U.S. The real sales opportunity for chemical makers is in row crops and lawns, not specialty crops.

In the example with Stinger herbicide, I mentioned in my last post, I think it’s purely that some companies did not choose to register their formulations of clopyralid for use in orchards and have nothing to do with inert ingredients, since the herbicide is not even used on the fruits.

Olpea, the list of inactive ingredients isn’t available to the public, is it?

Yes, it amazes me how careful the gov is about human exposure to pesticides and yet utterly sanguine about thousands of industrial chemicals to which we are constantly exposed.

If a pesticide left a residue of synthetic estrogen on fruit anywhere near the rate that legal food carrying plastics bleed on their contents it would be banned quicker than a bureaucrats bat of an eye.