In case anyone was interested in experimenting with Agriphage for fireblight control this season, wanted to pass on some info we've accumulated.

Agriphage Fireblight consists of bacteriophages that specifically parasitize Erwinia amylovora. Phages have a special place in our hearts, as some of my mother's research background involved them, and we've been dying to try Agriphage for the past couple of years.

It's manufactured by OmniLytics, bacteriophage specialists, for Certis. Any questions about the product, go directly to the R&D guys at Omnilytics -- they really know their stuff, are passionate about their products, and want to gather as much info as possible about them. They offered to test Agriphage against anything we want to tank-mix with it, free of charge; we just send them samples.

So far, they've found copper, iron, and zinc sensitivities to be the only things you need to worry about with Agriphage. They've tested Trilogy against it, as well, and Certis is basing their assertion that neem/azadirachtin is compatible on that particular study only. Note, Trilogy has a much lower neem oil content than other products, so while we don't expect any particular sensitivity, we will have OmniLytics test compatibility on TerraNeem or pure neem oil to be sure.

Cost via 7 Springs Farm is $515 per case (consisting of two 2.5 gallon jugs), and not normal stock, so not available without special order. We are lucky enough to live 1.5 hours from 7 Springs, so no drop shipping charges for the many cases we will use this season, but a lump $100-200 special order shipping charge to get it to 7 Springs, then pick it up in person.

Right now, we are planning on applying Agriphage 3 times surrounding bloom, starting at green tip (we know we've got plenty of Erwinia out there for the phages to feast on already after a very bad fireblight year in 2020). We're hoping to mix it right in with our regular holistic cocktail mix, but a surprising component, Micro-Pak, which contains some zinc and copper, may be an issue.

FYI, and will post how it all turns out . . .

Kordick Family Farm
Westfield, NC
Zone 7a



Edited 1 time(s). Last edit at 02/13/2021 08:42PM by Brittany Kordick.

I read somewhere that in tomatoes they were using the agriphage with skim milk powder and corn starch to lessen the effects of UV radiation and, thus, giving the phages a bit more time on the tree. Seems like Surround could be a good step in that direction in terms of phage cocktails (perhaps that's been mentioned somewhere on this forum already, my apologies if so).

I'm interested to hear how this goes for you. Good luck!

An update on Agriphage from the thick of extreme fireblight time in north-central North Carolina:

We are not completely out of the fireblight woods yet, but we're very pleased with Agriphage so far. After an early sprayer break, we missed out on two intended sprays back to back during bloom and prime infection time. We had done one spray just prior to greentip at that point, and have since picked up with two more orchard-wide sprays, and a couple of variety-specific ones beyond that in our historically bad fireblight trees. We didn't get our pruning completely done, as usual, and the Hewe's Crabs were one of those that missed out -- not good since they were the absolute worst hit with fireblight last year, to the point where they had zero green on the trees at the worst of it, and you can imagine how much dead wood and likely cankers were hanging out on these full-grown M111 trees. So plenty of inoculum out there, probably the most we've ever had, in spite of our heavy lime sulfur and copper and PerCarb sprays while dormant to attempt to clean up as much as possible.

Then the weather: three hard freezes during bloom, one bad hailstorm, and damaging high winds for about a week, which tore everything up pretty good. Lots of damaged tissue, and we've been in a state of perpetual extreme fireblight warnings according to our weather station-linked NEWA modeling for the better part of 2.5 weeks now. We've got some strikes out there, but they are very minor and far less than usual (and far, far less than you would expect following last year's over the top infection rate), not very widespread, specific to high inoculum sites. It ain't over yet, but the labor saved (we haven't had time to cut out strikes, and aren't worrying about killing ourselves to keep up with them for once -- the visual infection sites seem to halt in their tracks after an Agriphage app; more than a week after a shoot goes down, there is no noticeable oozing or spread, it's just . . . dead), etc. is definitely worth the price in a fireblight-lousy orchard in our opinions.

We have enough Agriphage left to do one more spray at a lower rate, but we're going to hang onto that in case we need an emergency cleanup. Based on what we've seen, we will probably use Agriphage again next year to keep going with our bigtime fireblight cleanup, but for other orchards, I envision Agriphage as something you'd do every couple or few years after fireblight gets out of control, just for a big cleanup.

We also have some compatibility testing updates after OmniLytics tested several product samples we sent in:

So two "duh" incompatibles were lime sulfur and PerCarb; they killed the bacteriophages outright.

Several perfectly compatible mixers: Quantum Light, SeaCrop, karanja oil, TerraNeem, ReBound Manganese.

And a couple with caveats: EM-1 and HoloCal inactivated one of the three Agriphage phages at 24 hours, but it was fine at the 4, 6, and 12 hour mark. Per the tester: "My recommendation is to make sure that you mix and spray ASAP when combining AgriPhage with those two. Don’t let the AgriPhage sit out in the same tank with those chemicals for too long." There is probably something in the formulations of these two products that acts to block the receptors on the phage in question. AgSil was another product that passed at 4 hours, but at 8 hours, was starting to kill phages. The tester felt it could be OK to tank-mix AgSil and Agriphage as long as you spray it immediately.

Of our three Agriphage sprays, the first was sprayed alone, out of extreme caution, since our compatibility testing wasn't finished yet. The second and third ones we risked adding mixers and Agriphage was added to our holistic mix cocktail, which contained EM-1, etc., but not AgSil.

Kordick Family Farm
Westfield, NC
Zone 7a



Edited 1 time(s). Last edit at 05/08/2021 02:35PM by Brittany Kordick.

Thank you for this great information. I tried AG this season. Like you, I’m still checking for new symptoms. So far only the Bedan are showing strikes. They bloomed really strangly—in three stages spread over weeks. I missed spraying the last bloom and I think these are the ones that got hit. Also, I did tank mix with potassium bicarbonate once. Do you know anything about compatibility with Pot bicarbonate?

Nat Bouman
Growing cider varieties in Zone 5b
On B.118 at 18X24
Susquehanna County, Pennsylvania

We are not currently using potassium bicarbonate in our orchard, so did not ask OmniLytics to test it against the bacteriophages in AgriPhage. However, I would fully expect potassium bicarbonate to be devastating to bacteriophages, and definitely wouldn't tank mix AgriPhage with it. While bacteriophages are not fungi, which are particularly susceptible to potassium bicarbonate, they are "living" in a sense, as viruses, and like so many biologicals, are fairly sensitive. The closest spray component to potassium bicarbonate we use would be PerCarb, a sodium carbonate formulation used to treat bacterial/fungal infections broad spectrum; we use it when a particularly blank disease inoculum slate is desired. As mentioned in an above post, we did submit PerCarb for testing against AgriPhage Fireblight, and it killed all three phages in the blend outright upon contact. I would assume that potassium carbonate would do the same, but you never know. If you're particularly keen to do a regular mix of AgriPhage and potassium bicarbonate, I would contact OmniLytics about doing a test, or even just give them a call, as they may already know the answer to this question definitively.

Kordick Family Farm
Westfield, NC
Zone 7a

As we gear up for spring sprays and revisit our Agriphage plans, one further crucial detail to report: the bacteriophages in Agriphage will not actually replicate unless it's 60 degrees. As such, the R&D guys don't recommend spraying until it's 60-65 degrees daytime temps on average since you may not get huge benefit (a bacteriophage would literally have to land smack on an Erwinia amylovora bacterium to kill it; they don't move around a whole lot). They offer the caveat that temps tend to be slightly higher within blossoms, so once buds open, definitely look at applying Agriphage. For that matter, the Erwinia has to be not only present, but at a susceptible stage, as well, which usually doesn't happen until temps warm up.

So this year we're tweaking our plan to begin spraying closer to pink stage, rather than last year's greentip, and will be keeping a closer eye on temps surrounding application. Previously, thinking had been that, coming off a bad fireblight year in an orchard, a pre-bloom Agriphage "cleanup" spray would be beneficial. Our thinking is now more along the lines that it wouldn't do any harm, but might not do a whole lot of good until a little bit later.

Kordick Family Farm
Westfield, NC
Zone 7a

Brittany, you described how Agriphage seemed to halt the spread of infection. I observed this as well. I missed a key moment with a late bloom in hot weather. Got some strikes. Sprayed Agriphage after the fact and the infection seemed to stop at the spur. No oozing, no canker developed, no no shepherd's crooks, despite a lot of heat and rain. The spur dried up and that seems to be it. Normally I would have pruned off the branch 18" below the strike--and I did do this on a bunch of trees but I decided to leave a few on and monitor. I did not observe any advance of the disease--and that seems to still be true nearly a year later.

Nat Bouman
Growing cider varieties in Zone 5b
On B.118 at 18X24
Susquehanna County, Pennsylvania

Glad to hear of your experience, Nat! It's become rare that we prune out any strikes in our orchard now that we're using Agriphage . . . and this is a huge deal, considering that previously for a few weeks around this time every year we were doing little else but pruning out strikes. Not only do we see fewer and fewer, but since they do just dry up and die we are happy to let that pruning wait until winter.

We asked OmniLytics to do some additional compatibility testing for us this spring and here are the results, fyi:

Howler, Lalstop G46, and Grandevo were all compatible at 24 hours. Lalstim Osmo was compatible at 1 and 4 hours, but not at 24 hours; the lab thinks tank-mixing for immediate spray would be fine on the Lalstim Osmo, just don't let it sit long.

Kordick Family Farm
Westfield, NC
Zone 7a



Edited 1 time(s). Last edit at 05/11/2022 03:12AM by Brittany Kordick.

This is excellent! I spoke with Daniel at Seven Springs Farm and he said to contact the "Agriphage Expert User", Brittany Kordick.

Here's some questions a couple of us growers in New England have about working with Agriphage. (I'm waiting for my shipment of Agriphage to come in, since I was out of town when the the season's first episode of Fireblight arrived Sunday May 11, 2022 / Monday May 12, 2022.

We are expecting another epsiode of Fireblight this coming Sunday May 22 and Monday May 23, 2022.

Questions:

1. How many hours after a Fire Blight Episode but before another rain event should Agriphage be applied?
2. What are the MIN. and MAX. temperatures to apply Agriphage?
3. What are the intervals? (Each time after a FB Strike? when there is no rain for 24 hours? or every week after the first time you treat orchard
with Fireblight?
4. What's the coverage on leaves, flowers, branches and trunk?
(Should run off be "Slow Drip" or "Fast Drip"?)
5. What is the duration of applications? For example, should Agriphage be applied on a weekly basis all summer long?
6. Have you tested tank mixing Agriphage with nutritionals such as Biotin Calcium or Boron? If so, is it recommended to tank mix these minerals?

Thank You so much for helping us New England growers, (who are experiencing this disease in Apple Trees more than ever.)

Sue Haynie
Sweet Seasons Farm
Zone 4 in northeastern Vermont

We are no Agriphage (or fireblight) experts, nor have we participated in any studies regarding either -- we are growers just like you who risked some skin on trying something new that there wasn't a lot of info on. I'm happy to report from the field on how it's going for us, but my "field" is in a very different part of the country than yours, with different climate, levels of pressure, and any number of variables. I hope anyone else using Agriphage out there will consider sharing their experiences here, as I have, as it serves to give us all a much more rounded picture of how to deploy bacteriophages against fireblight effectively.

Most of your questions can be most appropriately answered by contacting Certis and speaking to a rep -- it's the job of these guys to be on call for growers with questions like yours, and we spend lots of time talking to them as we try and understand and get to know a product. They know the technical aspects of their products a lot better than we do. I responded to your personal email/voicemail last night with the best answers I can give without calling a rep or scouring the Agriphage label myself, and I will post them here below.

As Todd recently noted in a different thread regarding RHAB control, using big gun packaged products can make you complacent. By the time you've done all the work of product research, product spending, work of application, etc., you don't unreasonably feel like you've done enough work here. We've been humbled this fireblight season, which we are currently at the height of in our orchard, and our thinking about fireblight control seems to evolve as rapidly as the damn bacterium itself. Our hope for this season was that our extensive use of Agriphage thus far would have reduced inoculum to the point that we could expect to see less and less incidence in our orchard going forward. Ha, if it was that easy, everyone would have these delusions of grandeur. We had almost zero blossom blight this year after keeping up with Agriphage sprays as best as we can straddling 175 different bloomtimes (and we also use Blossom Protect in our most prolific bloomers that we noticed in the past tend to be early vectors for fireblight spread, and other practices/spray components may also play a part). We were feeling tentatively cocky. Then about two weeks ago (well past petal fall on all varieties but a couple of late bloomers) we started seeing some very minimal fireblight in the orchard. And from there . . .

Long story short, we were dismayed to see surprising spread in the orchard (still nothing like what we're accustomed to, and nothing particularly devastating) from there these past two weeks. But we were applying Agriphage very intelligently and every season we feel like our understanding of fireblight improves! What could have happened? There's no way that Erwinia could have developed resistance to the phages that fast. We also spot treat (instead of cutting out strikes) with a little squirt bottle if we just have a strike here and there, and infections were resolving after application in this manner, so product clearly still working.

Using NEWA disease modelling data affiliated with our on-farm weather station, we pinpointed a particular date as the likely infection event for most of what we were seeing. Well, two weeks ago I monkeyed with the calibration on our sprayer in an attempt to solve some residual issues and make for more efficient sprays. I did an Agriphage application to try it out, and it went great -- I used 1/3 less tanks than I had in the past . . . and thus, applied a low-medium rate of Agriphage as opposed to our usual high rate surrounding the biggest infection event of our year so far. I didn't think of going out and applying more, just that that should be sufficient, and given that it was prime infection time, I'd follow up with a higher rate of spray soon.

As stated above, bacteriophages are not highly mobile -- they really need to land on a bacterium to annihilate it. What limited movement they have comes primarily from the replication process, after which more of them are "propelled" to new locations. So it's likely that there was a ton of Erwinia out there and not enough phages hitting them to take care of them before infection could ensue. We were talking about it afterwards and about how folks with low fireblight incidence in their orchards might be tempted to use low rates of Agriphage in their orchards, especially given the very high cost of the product. Ironically, if you have a relatively low population of Erwinia, you are even less likely to take care of it by applying a low rate of Agriphage since the phages will be less likely to come into contact with the bacteria. Thus, we plan to do more and more IPM style scouting and more high rate spot treatments to save product until fireblight infection becomes orchard-wide annually.

So the takeway so far for this season is, yeah, don't get complacent -- Agriphage is not a silver bullet and while we may not spend weeks cutting out strikes from sunup to sundown anymore to little positive effect, in our climate we are always going to be spending weeks of our year consumed with fireblight to the detriment of all else in our orchard. The situation changes too rapidly to do otherwise. We were doing an excellent job scouting daily this year and so thrilled to see such little blossom blight, but it takes so little to get out of control, and it does it so quickly. When I spot treat, I am always amazed to see how localized infections over several shoots can be obviously traced back to a single miniscule blossom blight in the vicinity. A couple days ago, we had made an application plan to apply Agriphage immediately again to our only two "bad" infection blocks in the orchard. Woke up to a 40% chance of rain, and disturbing amounts of ooze indicating active infection in other trees throughout the orchard. Full spray it was, and fast. Moral of the story: fireblight sucks and keep up with your legwork, not just your spray apps.



Re: AgriPhage and New England Holistic Apple Orchards
Kordick Family Farm
Hi Sue,

I hope Agriphage works as well for you as it has for us! Fireblight is such a pain, to put it extremely mildly, and while Agriphage is no silver bullet, we are thrilled to have it in our arsenal. We're in the thick of extreme fireblight infection period down here, and I've thought of a few things to add to the HON thread regarding Agriphage, so I'll try and do that soon (basically, use the highest recommended rate whenever possible since the bacteriophages aren't particularly mobile; if low pressure overall, rely on spot treatments at high rates to save product). I would recommend that you call Certis and talk to a rep about any general questions you have. They can tell you much more about it technically than we can, and the more you understand about the product, the easier it will be for you to make decisions about rate, when to spray, etc. in your particular situation.

I honestly don't remember how rainfast Agriphage is supposed to be, but it generally doesn't stick around in the environment long (even if there's a high population of Erwinia amylovora, the bacteriophages will kill off the bacteria fairly quickly, then die off themselves once the bacteria are depleted, so if you're in a climate or situation where more Erwinia are moving in regularly or cankers are releasing them locally, you do need to keep applying to replenish populations). That said, circumstances will usually dictate what we do, and the other day we were spraying over the course of a stormy day when a downpour ensued. I kept spraying through it all, knowing that most of what I was doing would be washed off, but being that we had some shoot blight going and my tank was already mixed, it made sense at the time to keep going in hope that some of the bacteriophages stayed in the canopy and did something for us before the rest of the forecast warm rain hit. Most times, it probably wouldn't, but every time is different.

Likewise, I am not aware of any upper temp range for Agriphage application -- good question for a Certis rep. Basically, if Erwinia amylovora is active, the bacteriophages should be, too. In our minds, 65-85 degrees is prime infection weather, and once it hits 90 degree temps regularly, fireblight slows down and may not warrant protection -- but this is what we believe we can say in our climate -- VT is a whole 'nother ballgame.

The intervals of our sprays depend on too many variables to say definitively -- sometimes a few days, sometimes a few weeks, depending on infection risk, weather, trauma events, infection observation in the orchard, etc. We plan for every 7-14 days, with some sprays occurring weeks apart, and some as few as 3 days apart, thus making for some kind of average. We try to have an extra spray's worth of Agriphage on hand beyond our expected seasonal needs in case of emergency treatment needs.

You can check with a Certis rep, but I'm remembering that the label specifies not to apply Agriphage to runoff.

As far as trunk and limb coverage, this gets into "disease theory." You can use Agriphage on cankers (but timing has to be right -- applying it in winter when Erwinia bacteria are latent won't do anything; they need to be active in warmer temperatures for them to be vulnerable). If you don't have cankers that you're specifically targeting with a direct spray, I wouldn't go out of my way to get coverage on non leaf/flower tissue . . . but I'm not sure it's not a good thing to hit as much of the tree in general as possible, given that Erwinia may overwinter in ways that are not commonly understood. Knowing your enemy is key here, and if you're not a fireblight researcher (we're sure not), that can be tough.

In NC, our fireblight pressure tends to abate by mid-June, whether it's to do with Erwinia life cycle or temps too consistently hot for them to thrive, or hardened-off foliage being less susceptible to infection, all of the above, we don't know. The modelling tells us that we're at extreme risk for months afterwards, but aside from a spot of shoot blight here and there, we really don't see that manifest in the orchard. Of course, if we got a hailstorm in August, that might change things. I'm really not sure how the lifecycle of fireblight would play out in a Northern climate.

We have only tested/tank-mixed with Agriphage the materials we have listed in this thread, but another great question for a rep, or you can see about doing some testing yourself and sharing what you find here.

Best of luck, and I hope you'll share your Agriphage experience in the HON thread as your season unfolds and you get your posting issues sorted out!

Kordick Family Farm
Westfield, NC
Zone 7a



Edited 6 time(s). Last edit at 05/21/2022 03:11PM by Brittany Kordick.

One final Agriphage thought: we do feel like we have taken care of a lot of our residual perennial fireblight pressure (ie, cankers) at this point. Our feeling of success comes from seeing trees that were our worst "fireblight magets" year in, year out, as some of our most pristine trees this season. Clearly, infection will always come down to weather and timing and opportunity. Likewise, some of our historically most pristine trees are some of our worst hit this season. So success in a big way, we feel, but vigilance will always be key, and it will be exceedingly difficult to anticipate infection, given all the variables involved.

Kordick Family Farm
Westfield, NC
Zone 7a



Edited 1 time(s). Last edit at 05/19/2022 04:50PM by Brittany Kordick.