[Brittany Kordick]

All right, Madex is compatible with Agriphage. Keep in mind with all these supposed compatibilities, though, that the testing Omnilytics does for us checks to see whether or not a material is compatible with Agriphage, not vice versa. So we’ve established that nothing about the Madex granulovirus formulation deactivates or interferes with the efficacy of the bactericidal qualities of Agriphage. We do not know whether Agriphage has any adverse effects on Madex if tank-mixed together or applied in quick succession; that testing would have to be done by the Madex manufacturer, in this case Certis. This goes for all the materials we’ve reported as testing compatible with Agriphage over the years: we’ve established that their tank-mixing with Agriphage does not cause adverse effect to Agriphage, but that doesn’t necessarily mean that Agriphage doesn’t cause adverse effects to any of these materials in turn when tank-mixed. Just in case folks don’t realize that compatibilities are relative to the material being tested, occurred to me that this might need to be spelled out somewhere.

[Brittany Kordick]

Just getting into shoot blight season down here in North Carolina, so for us that means AgriPhage is in the spray mix again. We try to send in anything new to us, spray material-wise, that we might be interested in tank-mixing with AgriPhage to OmniLytics for compatibility testing. We just got word back that Botrystop, an OMRI-listed fungicide labelled for fireblight, as well, is completely compatible with AgriPhage. We’re in the process of having Madex, the viral formulation targeting codling moth and Oriental fruit moth, tested, as well, and will update this thread when we have the results back on that.

[Brittany Kordick]

The apple bagging trials continue and it’s become my tradition to offer an update of sorts annually, so here goes:

Unfortunately, the price of Clemson’s apple bags went up precipitously this year. It is now $200/1,000 bags vs. $150/1,000 in previous years, and shipping is limited to individual boxes at $20/1,000; unfortunately, they are not willing to go outside the parameters of their online setup to do bulk shipping (for example, if we order 10,000 bags, we will receive them in 10 little boxes at $20 a pop for shipping). On principle we had a really hard time ordering any at all given these changes, but are still unable to find any other source for fruit bags. I hemmed and hawed and procrastinated some more, and finally gave in and ordered 1,000 bags in May, which was way late, didn’t do much for us, but kept the trial going anyway for another year anyway.

Because I waited so long to order, this year’s experimental twist ended up being, what happens if you bag your fruit later than you should? I decided to run with it and necessarily bagged a month later than I had in previous years and did not bother doing any kind of sanitation spray step before bagging. There’s a lot going on right after petalfall and I figured it’s worth knowing whether late, lazy bagging will do anything for you. However, as usual, I did choose the most pristine fruits to bag and thinned appropriately. I knew that the fruits had likely been exposed to pathogens, even if development was not yet visible to the naked eye, but hoped that I would still be significantly limiting overall exposure. The good news: my bagging technique has really improved. Not only am I very efficient (typically, it takes me less than 10 seconds to bag a fruit, sometimes as few as 5), but as I monitored the bags over the next couple of months for drop-off due to poor technique, it was almost zero for 1,000 bags; the suckers stay on if you bag well. So I’ve got the practical aspect of bagging down: yes, it can be done, and efficiently. I just need to train a few more bodies to be as capable and enthusiastic as I am about it if I really want to ramp this up on a truly commercial scale.

Unfortunately, the results of late bagging are in, and guess what? Don’t do it. Over the several varieties that I bagged, I lost most of the fruits (dropped off into the still-attached bags). I suspect that, since they likely had built up some pathogen populations on the fruit surface by the time I bagged, the bags created an ideal environment for what was already there to thrive and may have exacerbated infection. So, unsurprisingly, the lesson is, yes, put your bags on in a timely manner, ideally only a couple of weeks after petal fall, when the fruitlets are 3/4 inch in diameter (basically, bag as early as you can — you do need to wait for the fruitlets to size up enough that it’s possible to bag). Also, do a sanitation step just prior to bagging — you want your fruitlets going into the bags clean, so they stay clean as the season progresses.

We’ve been telling many of our homeowner customers about bagging, knowing that most are not interested in keeping up with any kind of spray program. I was delighted recently to receive an email from someone who has a Fuji semi-dwarf tree in her yard, doesn’t spray or do much of anything beyond pruning, and had never gotten more than a handful of worthwhile fruits from her trees after years of hoping. She got some Clemson bags this season and wrote to tell me that she finally got to enjoy some fruit this year and that she didn’t see a speck of insect or disease damage on her bagged apples. She did mention that she still experienced some animal predation in the bagged fruits.

Which leads me to the next update: in the past, I’ve also touted the bags as protecting against deer damage, not as a result of personal experience (our orchards are entirely deer fenced), but due to hearing other apple baggers claim deer protection as an apple bagging virtue. Coincidentally, I must now concur with our homeowner friend that I don’t see the bags protecting against animal predation (but come on, you get disease, insect, sun, hail protection in one fell swoop — what more do you want?!). A doe got into our orchard a month or so ago and, not only did she tear into a bunch of my bagged fruit, she actually seemed to prefer it! She left unbagged apples alone and went for the bagged ones in the same tree; I actually watched her do this. No clue what the appeal could be, or if this is one strange deer’s fetish (suspect not, but who knows).

Finally, one last nugget of info gleaned this season: when I found out the Clemson bags had gone up in price, I did my usual exhaustive sweep, looking ways to procure fruit bags from other sources. No luck on paper bags, but I remembered that we had a box of “Maggot Barrier” bags laying around from years ago. These are domestically produced hosiery style bags from a small Massachusetts company: http://www.maggotbarriers.com. I’d never seriously considered them as an alternative to the paper fruit bags, assuming they would not protect against disease, just insect pests (they certainly do not claim to protect against pathogens, and I just assumed they would be too porous to do so). Well, I decided to put out what we had (equally late and not subject to sanitation spray) and I was encouraged enough by how easily and efficiently they went onto the fruits (I did a loose square knot, rather than the recommended rubber bands, and found that it took a little bit longer than paper bagging, but not much). I also loved that they were produced domestically and that they could be reused for more than a single season (you would definitely want to wash and sanitize them, though). I very nearly purchased a bunch more to use, but thankfully, managed to restrain myself to the small 100 bag trial I could manage with what I had on hand.

So the Maggot Barrier bags worked great for insects, but as expected, not so much for disease prevention (or at least sooty blotch/fly speck — full disclosure, I have not harvested enough of the Maggot Barrier-ed fruits yet to give a comprehensive report on whether or not they prevented other pathogen development). I will amend this post if I find that they did in fact, prevent a lot of fruit rot from occurring, but pre-harvest sampling of a few fruits proved that SBFS can waltz right through the fabric and thrive, no problem. Keep in mind that the fabric stays tight against the fruitlet as it grows, and that the fabric retains moisture, perhaps to a greater extent than the paper bags do. But for those of you in cooler climates where fruit rots are not the big bad that they are for those of us growing down South, perhaps Maggot Barriers are a good option for insect damage prevention.

Anyway, while all this was fresh in mind, wanted to jot down what I had to offer so far this year. Viva la apple bags! I really hope I can find a better source for them going forward and don’t have to cottage industry this into my own paper bag startup company.

[Brittany Kordick]

Just in time for fireblight season 2024 we recently asked OmniLytics to test compatibility on some materials in our orchard management plan this season. Firstly, we realized we’ve never asked them to test seaweed before, and given that some minerals cause issues with the phages, thought it would be wise to know for sure that we’re good with Maxicrop seaweed (@ 1-2 lbs/100 gal), instead of just assuming so. We also asked them to test Stargus at a rate of 1-2 quarts per 100 gallons. Finally, we have been using biodynamic paste (not homemade, but the actual Josephine Porter Institute formulation) to treat neonectria cankers in our orchard, but have been hand-spraying the cankers with concentrated AgriPhage before slathering with the BD paste (not thinned with water at all) as insurance in case any of the cankers we’re treating are, in fact, fireblight-derived, rather than from neonectria infection. We suspected that something in the BD paste would probably not be compatible with the phages in such application conditions (again, thinking of mineral content, primarily). OmniLytics did a great job of trying to simulate our field application scenario as best they could in the lab — they “covered a petri plate with a thin film of purified phages on the surface (no host for replication) with the mud for 24 hours to simulate being covered.”

The results:

Maxicrop Seaweed = compatible out to 24 hours
Biodynamic Paste = compatible out to 24 hours (and notably, concentrations of the phages did not drop at all after being covered with the paste for that long)
Stargus = somewhat compatible — compatible at 4 hours, but slowly dropped the concentration of phages, ultimately missing the 24 hour compatibility mark. Therefore, OmniLytics advised spraying Stargus + AgriPhage immediately after tank-mixing for best results

Sidenote: unsurprisingly, Blossom Protect/Buffer Protect is something orchardists might be keen to tank-mix with AgriPhage during blossom blight season, using the AgriPhage to wipe out existing Erwinia whilst simultaneously setting up subsequent protection in the blossoms with Blossom Protect. We’ve never combined the two products before, but thought there was a chance we might have occasion to do so this season, thus also queried OmniLytics about this scenario. They are very familiar with Blossom Protect and were able to give some good guidance re: combined usage with AgriPhage. There is a compatibility issue, but it is with the Buffer Protect additive that is usually combined with Blossom Protect to provide very acidic conditions that are inhospitable to E. amylovora. You definitely do not want to tank mix AgriPhage, Blossom Protect, and Buffer Protect (on the off chance that you do not purchase the Blossom/Buffer Protect kit, but only apply the Blossom Protect yeast formulation, you’re fine); the low pH is fatal to the phages. Our next question was, OK, if that’s the case, what if we applied AgriPhage and Blossom/Buffer Protect separately? OmniLytics’ advice in this scenario either to apply AgriPhage first, give it 1-2 days to work, then follow up with Blossom/Buffer Protect OR that you could apply AgriPhage as soon as the Buffer Protect was allowed to dry.

[Brittany Kordick]

We have had a RainWise weather station linked to NEWA in our orchard for a few years. We’re just about to set up a RIMPro subscription, and it’s led to some scrutiny of our current station setup. Upon purchase, RainWise advised us not to situate the station immediately within our orchard since it would be subject to sprays that could damage electronics (I think, in particular, we may have even mentioned to them at the time that we sprayed a lot of oil year round). So we set it up outside the orchard proper, but within 100 feet of an outer edge. To be in line with our wifi signal, we had to put the station in a location that is slightly protected by a woods line to the northwest, and over the years, we’ve become aware that our wind speed data is consistently lower mph than the orchard proper in this location, made worse by the fact that our wind direction is typically from the northwest. Since one of the RIMPro models we’re going to be taking advantage of likely factors in wind speed (or we hope it does, for accuracy sake), we’re revisiting moving the station. Some interesting questions have arisen as a result.

Since our weather station previously was not able to tabulate the wetting events associated with our sprays within the orchard, we’re wondering if any of our past modelling has been seriously affected. Granted, we spray with an airblast and so the duration of the wetting event is likely to be pretty short most of the time, but a wetting event is a wetting event. In hindsight, this would seem to be a great reason to situate a weather station directly in one’s orchard, so that it is truly subjected to everything the trees are. I wouldn’t want to hit it with certain materials like lime sulfur, but I suppose you could always put a garbage bag over it when you take a pass with a spray material that could damage the unit. On the other hand, we have let local community members, and regional growers and researchers know about our station and they also may take advantage of the modelling currently provided by NEWA. If we do move the station to a location that records more wetting events and modelling is impacted, then the modelling would not be well calibrated for any location outside our orchard.

All this has made me wonder where most orchardists choose to locate their stations — within the orchard proper or outside, but close by?

[Brittany Kordick]

Just updating this thread to confirm that, after deploying Golden Chalcid parasitic wasps in our orchard during the past growing season, we feel we can report success in controlling our San Jose and Oystershell scale populations. We initially noticed rising populations during pruning of our dormant trees a year ago, as we scrutinized individual limbs. Happily, as we dormant-prune this year, we can report that we are not seeing any active scale! The wasps were sort of a pain to work with, but are a well-regarded control for scale, so it’s nice to know that they were indeed worth the trouble and are a cost-effective non-spray option for controlling scale even on large acreage tree plantings.

[Brittany Kordick]

I am curious about the longevity of biodynamic tree paste post-application. We have come across some very interesting research concerning use of “mud packs” to treat Cryphonectria infections of chestnut and are interesting in utilizing tree paste to pack our cankers during this dormant season. For the chestnut mud packs, the researcher recommends wrapping the mud-packed canker with plastic wrap to prevent the mud from washing off. I understand that biodynamic tree pastes vary around the base recipe and perhaps some additions could be made to enhance longevity, but just curious, especially with regards to using it to treat cankers of any type, if you generally apply the paste once and count on it hanging around long enough to do its thing, or if you are in an apply as needed situation, wherein you usually must follow up as the paste breaks down over time.

[Brittany Kordick]

Thank you so much for putting together this outstanding presentation and letting us know about it! We use several of the NEWA pest/disease models to help guide the management of our orchard, but I admit, I always assumed that trying to comprehend, follow, and apply the pollen tube growth model would be a bridge too far for us to implement in our particular setup. Thus, I’ve generally glossed over any presentations and studies having to do with the model and only mildly wondered what I might be missing. When I saw that your video presentation regarding your on-farm research was about 30 minutes long I nearly skipped it, as well, but I’m so glad I didn’t. You do a wonderful job of breaking down the flower to fruit process (very helpful diagrams, by the way), introducing growers to the PTGM model and evaluating your own thinning trials. Watching your video saved me an immense amount of time, just in terms of the time I’d have otherwise spent sifting through info to understand how the model works, let alone the time and expense of actually playing with Regalia and oil for thinning in our own orchard. Unfortunately, of course, it all served to confirm my instinct that trying to utilize the PTGM is not for us in our orchard!

I also skimmed your more in-depth research report and particularly appreciate the insights you included at the end about the thinning difficulties presented by 1 year old wood.

Thank you also for the other valuable data from on-farm research you’ve made available on your website! Your dried apple “trials” are of particular interest to us as many of the original varieties we planted in our orchard were specifically for their usage dried.

Well done and thanks again for sharing!

[Brittany Kordick]

It’s been a few years since this idea of constructing a cooler from straw bales was floated, but it has captured my imagination as we find that any larger scale options for refrigeration are increasingly hard to justify (yet absolutely necessary, regardless) economically. Time was, you could pick up a used walk-in at an auction or in classifieds for a song or go the shipping container route. Seems like everyone and their mother’s gotten savvy to these options, as well as the resale profits to be had, and I can’t count how many times I’ve seen used walk-ins and containers go for prices higher than what I’d think possible for brand-new ones. There’s got to be another way.

So I started thinking about building a cooler with straw bales. On the surface, it’s a great concept: once the fairly simple principles of building are mastered, you can apply them to build as big or as small a cooler as you like, and the R-values of using bales exceed that of the insulation typical of walk-in paneling. Also seems ideal for use with a Coolbot and a/c setup — sure would be simpler than building a straw bale house, to just build a cube structure with a single or few windows to accommodate an a/c plus. What I’m hung up on is the humidity aspect. The whole idea of straw bale structures is that the walls are breathable. We would want any cooler we build to have washable interior walls, and this would seem impossible, given the plasters typically used in straw bale structures; one abiding principle of straw bale building appears to be that you build a substantial roof overhang and employ guttering specifically to prevent habitual wetting of plastered exterior walls. OK, so what if we line the interior with a more standard construction or salvage material that is cheap and washable — say linoleum? But surely that will affect the integrity of the entire structure from a breathability standpoint since we’ve effectively rendered it one-way breathable, from exterior only.

Also of concern: the current economics of building a straw bale cooler; will we actually ultimately see savings compared with the other expensive options out there? Several years ago, we remember purchasing straw bales for $2 a bale; this was once one of the biggest attractions of building with straw bales — you’re using an agricultural waste product AND it’s cheap! Obviously, times have changed as more farmers opt to till in their straw stubble; nowadays straw is often as or more expensive than a square bale of hay and in the neighborhood of $8 a bale in our area. Perhaps by the time we budget this out accordingly, it will not seem quite like the economical option it does on the surface.

But before we do take the time to painstakingly budget this out, I’m just wondering if anyone on the forum with any experience building with straw bales can weigh in on the humidity/washability concerns in general. We would like to build a test 8 by 10 cooler, and figure we’ll need approximately 100 straw bales, as well as rebar, mesh, foundation material, lumber, etc., so before we sink $800 plus into a test structure, it would be good to have higher conceptual confidence in building a cooler that lasts for years or decades, rather than starting to rot after a single season.

[Brittany Kordick]

We are knee-deep in dormant pruning and dismayed to see the degree to which nectria cankers have pervaded our orchard after years of essentially non-treatment due to our assumption of cause by fireblight. And since we’ve been so successful in treating fireblight cankers by scraping and saturating them with AgriPhage, we’ve increasingly left any large cankers we find during pruning and treated them in this fashion . . . but now we’re finding that many or most of these are, in fact, due to nectria colonization, rather than fireblight (or who knows, perhaps black rot, or any number of pathogens capable of forming cankers). Of course, wherever possible, we’ve gone back to removing cankers, but when it would necessitate removing a particularly precious limb or removing a significant section of the central leader, we’ve been going wobbly and just excavating the canker, hoping to experiment with treatments (hand saturation with concentrated lime sulfur, hand inoculation with Lalstop G46 — fight a sap fungus with a sap fungus, hoping for outcompetition, plastering with neem butter or biodynamic paste, etc.), as well as irritating the healthy live tissue surrounding, hoping to spur the sealing process to get on with it.

So as we make these hard decisions, we’ve become really interested in understanding more about the nectria cankers themselves, particularly the extent to which they may encompass and parasitize living tissue beyond acting saprophytically on dead tissue. Indeed, one of the most insidious aspects of nectria is this ability to colonize as a sap fungus, before turning parasitic and infecting living tissue. Because of the rampant colonization of certain varietal blocks, I am also interested in the idea of systemic treatment of cankers via trunk injection, but since I understand the canker to be comprised primarily of dead wood, I must question whether such treatment, assuming an appropriate material could even be identified, as well, as the proper timing to apply it, would be worthwhile at all.

We understand that nectria-cankered trees end up in something like an annual give-and-take battle with the fungus, where the fungus never actually dies off; the tree just lives with it. This concept reminds me a lot of Dr. Srdjan Acimovic’s research surrounding fall and winter development of fireblight cankers, where the trees effectively wall off the fungus, but in doing so, can actually protect and preserve the cankers to future detriment. But nectria does not derive from bacterial pathogens and usually starts as a saprophytic fungus on dead wood . . . so we are wondering, if the tree does seal off a nectria canker, unlike with bacterial fireblight, has it effectively cured itself of that particular canker? I don’t believe the fungus would be able to sporulate the next season, but again, I’m not sure to what extent it could still potentially harm living tissue within the tree or simply survive within until . . .

All this has really made me wish for a better understanding of pathogenic cankers in general, to be able to better identify their sources and assess possible action steps. For example, when is dead wood just dead wood? Or even if one did feel like a large canker was inactive or sufficiently hand-treated, in a nectria-stricken orchard like ours, where residual inoculum and reinfection is likely in the short term, is exposed dead wood always to be treated like a liability? I remember reading an article about nectria that detailed the risk “almost always associated with “pulled stems” left when harvesters remove apples, but leave stems in the trees.” I’m wondering if perhaps we created the perfect storm for nectria in more ways than one in our orchard: lots of fireblight inoculum in the form of dead wood dating back years, subsequent mis-treatment as fireblight, but also, after a couple of years of heavy pruning of very large limbs as we catch up in vigorous blocks, leaving tons of unusually large cut ends on a given tree for inoculation as dry, “dead” wood that remain unsealed for several seasons following.

Don’t really have anything new to report — obviously, we’ll see if our efforts at controlling nectria pay off, come mid-June, when we typically see drastic die-back. I think organic orchardists of all stripes necessarily have a higher incidence rate and tolerance for retention of cankers in their orchards (whether we should or not) when compared with conventional growers. This is really just a food for thought update, reflecting the need for a thread looking closer at the differences and similarities of various common pathogenic cankers with regard to identification, assessment and treatment.