plant sap analysis

This year's research efforts center around fine-tuning foliar nutrients based on three rounds of plant sap analysis. One goal here is to identify the timing of essential nutrients with respect to flower viability, cell division in the fruitlet, and robust photosynthesis all summer long. Leaf samples are being taken from the same trees each time in two different blocks. The block aspect let's me tweak timing nuance and even run effectiveness comparisons between specific nutrient formulations. Needless to say, useful things are being learned. Grower-members will be able to find my "sap log" in the Secret Tattoo at the end of this summer, which is when this discussion hopefully takes off. I expect to do three rounds of sap analysis again in 2021 and 2022 to further establish a baseline understanding all fruit growers can utilize. This in turn allows some soil work (especially gypsum) before next year's buds unfurl.

Meanwhile, I am touching base with several other growers who are also working with plant sap analysis. Oxidized minerals like manganese seem to come up short across the board. Establishing a deep green hue is all about iron and magnesium. Calcium is the kingpin, and how this ties to the pulsing of boron and potassium across the season absolutely fascinating. Another goal is to try to get a handle on "soil constitution" to be able to provide community-scale growers a package approach to recommendations. Perhaps this will be based on Cation Exchange Capacity and base saturation ratios. Or it may be every grower needs to touch base at least once (spending a hundred bucks for a single sap analysis) to get a sense of underlying site parameters. I'm tabulating such data if you're in a position to share your insights and results.

The third goal in this project is to find out when homegrown remedies suit, be it fermented plant extracts or mineralized concoctions with organic chelates. Epsom salts, for instance, are the traditional way to up magnesium levels, and certainly far more economical than paying shipping charges on a liquid product. But what if we learn how to make that delivery of magnesium sulfate even more effective than merely dissolving salts in the bath (spray tank) water? Those of you with homegrown formulating experience should get in touch as well, whether by adding your bit to this thread or emailing me direct at michael@groworganicapples.com.

Tree nutrition from the holistic perspective . . . who would have thunk it?

Lost Nation Orchard
Zone 4b in New Hampshire



Edited 4 time(s). Last edit at 01/24/2022 03:28PM by Michael Phillips.

Now exploring some further questions pertaining to plant sap analysis asked in the formulating assist thread posted in Tree Fruit Nutrition.

All testing is certainly reductionist and so even "rock solid numbers" should be interpreted in a life forces context. Plant sap readings reflect actual nutrient uptake in molecular forms most directly tied to photosynthesis efficiency. Readings through the season help me see how deficiency and/or excess of certain nutrients affect the whole green scene... and how I as a tree steward can help pulse the situation back to balance. This seems especially pertinent in agriculture where we need to address both ecosystem and soil disturbance, radically shifting climate dynamics, and enhanced disease prospects brought about in part by global pollution raining down on our farms and homesteads wherever we be. There is no longer a free ride for fruit trees just because we spread quality compost. Working with foliar remedies to boost healthy plant metabolism strikes me as pivotal to succeeding as a holistic orchardist. So regardless where that brief diatribe just came from... let's examine plant sap analysis on a practical level.

I have been working through Crop Health Labs to get plant sap content (via leaf samples) analyzed. In truth, this "lab" is a subsidiary of Advancing Eco Ag (AEA) in Ohio, and in that sense ties to the company mission to sell growers a range of quality foliar products. The actual lab work is done by Nova Crop Control in the Netherlands. I talk with AEA advisors—specifically, Nathan Harman in 2019 & 2020 and Kish Johnson in 2021—to interpret the results in a fruit tree context. I learn things from them and they in turn learn things from me. The AEA team purportedly tweaks the targeted optimum range for each nutrient for different crop groupings each winter in accordance with lessons learned the prior growing season. While John Kempf and company at AEA get to look at hundreds of sap results from across an array of production systems, I have at best monitored six other orchards in this respect, either in a consultant context or for research sharing purposes. The AEA target ranges are likely more concise than what is provided by the Nova Crop folks in Europe, though as Mike Biltonen pointed out, we're not often let in on the back story behind such tweaks. I get to see any shifts in optimums adopted by Crop Health Labs at the close of each season when I receive a compilation of the three rounds of sap testing, this presented in a single page format for each variety being tested. (Plant sap results within the season are provided in the Nova Crop construct.) I have also been communicating directly with the Nova Crop scientists as well as other crop consultants and product formulators in trying to understand the big picture. Again, repeating what Mike said in that other thread, this is new territory and we are indeed all in learning mode!

I literally see the results of chosen spray applications with regard to what "took" with respect to each nutrient level in real time at late pink, the conclusion of the cell division phase, and at terminal bud set. Admittedly, my eye keys more to overall trends more so than precisely hitting individual targeted optimums. One reading to especially watch is Total Sugars, which indeed increased for both tested varieties as the growing season progressed. This is as close as we can come to gauging photosynthesis efficiency and thus a holy grail unto itself. Now is the time of year I further analyze these numbers to better understand how to proceed with nutrient formulations in the growing season to come.

Given that our species is in desperate need of intelligence boosting—hopefully to result from eating nutrient dense foods—makes this work all the more critical!

Lost Nation Orchard
Zone 4b in New Hampshire



Edited 2 time(s). Last edit at 01/04/2022 06:14PM by Michael Phillips.

We've emailed about plant sap analysis before, so I know that in addition to my general, and apparently Mike B's more specific and experienced, mixed feelings about it (detailed in the "formulating assist" thread under "Tree Fruit Nutrition"), no one in the HON seems to be as excited as you are about it so far. I'm going to peg this as yet another we-be-contrarians thing -- a lot of HON orchardists understandably seem to have paying-lots-of-money-for-stuff issues, trusting big commercial entity issues, etc. But I am surprised that our hard cider maker contingent doesn't appear to be particularly interested in plant sap analysis, if only within the context of the consuming quest for perfect (cider biology and chemistry-wise) fruit, though it makes sense that gleaners and foragers who aren't actively in-putting to orchards wouldn't be.

The funny thing is, we're seeing the conventional folks jump way on the plant sap analysis bandwagon! It's a trendy thing all of a sudden, that we see referenced in publications like 'American Fruit Grower,' 'Good Fruit Grower,' etc. Also, I was supposed to be hearing about it in person at the big NC Apple Growers Association meeting this week before they postponed the whole shebang due to the winter weather down here. It's not surprising to see the conventional trend move this way, as it's becoming all about data, data, data, and micro-managing your orchard . . . which is what I instinctively back away from philosophically, even as I appreciate the science behind this approach. Somehow it just takes all the fun and mystery out of apple-growing. I can't help being amused, though -- it's as if you advertised in a singles column to meet a nice, holistically-minded individual who enjoys productive chats about plant sap analysis, and lo, it's Mr. Monsanto with the pointy teeth who shows up at the rendezvous with a bouquet of flowers for you!

I am thrilled that things like plant sap analysis have been developed, and I agree that it really is a new frontier, and a gift to growers of "keys to the kingdom," as you have put it so well elsewhere. I don't want to be a freeloader, but I very much look forward to hearing where all this goes; people like you, who have such a thorough understanding of tree physiology and ecosystem biology, not to mention the passion for it, are the people that plant sap analysis was made for.

However, my personal growing interests and talents lie somewhat elsewhere, and if we are getting to the point where we have to do things like plant sap analysis in order to have a hope of growing even a halfway marketable (or homeowner grower-pleasing) apple, then I'm afraid my enthusiasm for apples is waning. In addition to ourselves, as commercial growers, I'm thinking of all the people buying apple trees from us, who just want a few non-soggyfilthladen, edible apples on a decent-looking tree, nothing major here, and that most of them have no idea what it's going to take to get there (and most will not be willing to spray holistic mixes every week or month, let alone do something like plant sap analysis).

While the actual cost of testing might not be that bad in the scheme of things, we realized, as we struggled to compute examples of sap analysis results, that this was going to be yet another compounded cost expenditure (we would have to pay someone to interpret the results for us and make recommendations, and while we would potentially save money based on some analysis values, odds are that other values would suggest new additions to the spray plan, something we are just not ready to wrap our brains or our wallets around yet, even if it does ultimately result in healthier trees/better crops).

There are so many improvements (that we actually understand and which don't just make our brains want to explode) that we know we can make right now to improve the health of our trees -- get that dormant pruning all done for once; do serious summer pruning; actually spend time training trees during the growing season; get that hay mulch out, not just in the same, usual places; whip fireblight, etc., so we did our best to focus on that this past non-fruit year.

One other general realization about plant sap analysis in our situation: it makes our heads hurt. A big takeaway from the Berkshire Roundtable in 2019 was that we all wish we could spend more time enjoying our orchards, and we are no exception. There's a big something to be said for crunching numbers and analyzing values and understanding the holistic picture, but honestly, it really takes a lot of the fun out of growing apples, and we feel like we spend so much of our time doing that already, and doing a very good job, actually, in a lot of ways, despite the constant need for improvement. And since we're not anywhere near making a living from the orchard, and since our biggest problem (fruit rots) is not going away, we've been trying to spend more time just enjoying what we do and taking care of the existing to-do wish list.

Don't mean to put out a downer, just offer an explanation for why some folks may not be inclined to jump on the plant sap analysis bandwagon, no matter the potential benefits to their orchard.

Kordick Family Farm
Westfield, NC
Zone 7a



Edited 2 time(s). Last edit at 01/18/2022 06:05PM by Brittany Kordick.

Bravo! A parry, a thrust, Agrippa! Feelings should be part of determining our priorities, so I can appreciate that the introduction of more numbers would seem contrary to spiritual connection with our trees and with working with nature. On the other hand, doing agriculture for a living does suggest we each want to be at the top of our game. Whatever one's utilization of soil testing and/or tissue testing and even refractometer readings to date—let's look at the sap analysis tool in terms of holistic orchard management.

The raison d'être for working with fruit tree nutrition is nudging photosynthesis to be more efficient. Trace mineral availability and cation balance are the drivers of healthy plant metabolism. Greater amounts of plant sugars produced—that tried and true carbon energy—means brisker trade between roots and soil organisms. This results in even more nutrients being directed throughout the plant community via fungal intelligence. This means healthier fruit for our families and communities. This means more reliable production from year to year as far as a viable living goes. Which brings the story back around to you and I, the fruit growers, and the role we might play through nutrient pulsing.

Here's a foundational construct meant to shift current perceptions: The small amount of mineral actually applied to a leaf through a foliar application may be utilized directly through stomata and pore absorption yet it may also be taken up by arboreal biology and subsequently directed within the leaf in the form of bacterial metabolites. What you might have heard about regarding bacterial penetration of root tips—called rhizophagy—happens as much above with shoot tips. Steve Becker at Tainio Biologicals and I jokingly refer to this as "phyllophagy" but science hasn't caught up with us as yet. Regardless, that absorbed nutrition is just as likely to be sent to the root zone where it serves as a signal to soil biology to deliver more of the same. It's so much vaster than an IV-like nutrient supply or conventional foliar feeding. Nor can we overlook redox where a mineral might well be on hand but in an oxidized form that's not useful in the metabolism process. So yes, if we're going to manage orchards for crop production, I think it's appropriate for humans to incorporate foliar nutrition into organic agriculture. Things get even better when you grasp that buds, twig bark, and trunks are part of this arboreal riff.

This step of using plant sap analysis to recognize trends and patterns at a given site is what will help us move beyond "symptoms management" of pests and disease and instead rely more fully on internal fortitude and outrageous diversity. I've come to see our work with the arboreal food web and nutrient prompts as the missing link in growing healthy fruit.

Let's explore both sides of the coin with respect to costs. Pondering use of external inputs should always be part of the decision process. Core to this research project is the use of fermented plant extracts (FPEs) and bionutrient ferments (BNFs) made on the farm from green herbs, mineral amendments, and specific biology. I guarantee everyone that a) you won't be gouged for shipping, and b) what's being shaped will be far less costly than pallets of sulfur, copper, double nickel, and what have you. No additional sprays are being made as nutrients work synergistically with the holistic plan as it now stands. That said, never lose sight of ramial woodchips and fungal compost remaining integral to long term soil fertility.

Plant sap analysis runs between $75 to $90 per sample. Plus you need to pay the postman for express shipping. A single test made at the end of the cell division phase—done just the once—provides a plausible sense of site constitution to know when certain assumptions apply or not. Those growers who opt for three rounds of testing a season can fine tune this all the more. Only larger growers, frankly, will be able to justify this year after year. I am thankful that four of my consulting clients are biting the bullet and willing to repeat sap analysis all three rounds for the coming season as this is helping me tremendously to both understand and convey the basics. So bear with me… for when this next book comes together next winter… there will be recommendations for "sap growers" of every stripe as well as those "seat-of-the-pants growers" who never delve into what numbers have to reveal.

Lost Nation Orchard
Zone 4b in New Hampshire



Edited 6 time(s). Last edit at 02/17/2022 03:50PM by Michael Phillips.

Hey Michael,

Could you clarify when to look for the "end of the cell division phase" in our orchards, given that it won't correspond to the same calendar date everywhere?

I'm sure I've read this elsewhere, but this type of info doesn't seem to stick in my mind, and it would help me (and maybe others) if you could give a brief explanation of what signs to look for.

THANX!

Craig Bickle
Hap Woods
Zone 6a
East-Central Ohio

Hi Craig,
I know you were asking MP, but hopefully I can provide some insight here. Cell division is understood to begin more or less at the time of fertilization and last for roughly 6 weeks. It may end sooner in warmer drier weather and slower in cooler wetter weather. The pollen germ tube takes about 6-8 days (lots of factors here) from the time it lands on the pistil of the flower to when it has grown down the style and into the ovary to fertilize the ovules. The period of successful fertilization is when CD begins. 6 weeks post-fertilization is a good rule of thumb for when CD ends and CL (cell enlargement) can be expected to begin.

Mike Biltonen, Know Your Roots
Zone 5b in New York

I'll simply add how the cell division phase appears in the holistic spray framework (the latest version of which members can view in the Secret Tattoo). The primary infection window takes us about a week beyond petal fall. This is followed by a four week window, more or less, dubbed the fruit sizing window when the bulk of cell division takes place. So much is going on during this period, from getting calcium into developing fruitlets to effective thinning to curculio incursions to the closing of the rust window. What are called "comp sprays" are indeed about embracing a comprehensive reality. We go on from there to the fruit ripening window where, as Mike explains, cell enlargement—ideally empowered by kick-ass photosynthesis—happens until the fruit gets picked and even beyond.

Round two of sap analysis happens following the Comp3 application. Nutrient trends have been determined by that point as far as innate soil capabilities go. There was a time when shipping leaf samples (right after Comp2) on a Monday by express mail meant that the shipment arrived Tuesday morning in Ohio to get to the Netherlands the next day... leading to results in hand by Friday... should I decide to tweak anything for the third comp spray. Now the concept of "overnight mail" has lost all meaning so that hustle doesn't have relevance. Regardless, the point here is that cell division has essentially wrapped up by the time you take R2 samples. Timing of this analysis may reveal certain excesses or deficiencies to address in summer sprays but for the most part nutrient pulsing is over now for the season.

Lost Nation Orchard
Zone 4b in New Hampshire



Edited 1 time(s). Last edit at 01/27/2022 02:07AM by Michael Phillips.

getting down to basics, what results are we trying to achieve from sap analysis and these various spray materials? Michael, you mention the better quality of last year's crop--what was better and how good was it? Do you have controlled comparison trees that didn't get the treatment(s)?

For those of us not already immersed in all this, it would be good to see specifics.

Thanks!

Hemlock Grove Farm
Zone 5 in New York

Good to have you join the fray, Brian! I not sure why 'sap' is being looked at as suspect when many of us already use soil testing and tissue testing to some degree, to be honest. Knowing about specific nutrient deficiencies and excesses—and subsequently trying to achieve a better sense of balance—seems fundamental to me as a holistic grower. I absolutely honor the intelligence inherent in the soil food web and think the arboreal food web deserves to be seen as equally awesome. I have shared that iron and manganese foliar applications should be separate because of known antagonisms, and my subsequent confirmation that sap results support this as the right means to overcome redox issues. I'm making headway with "synergistic silica" but still tweaking the applications. This year I'm also going to get a sense if separating calcium and magnesium applications post petal fall will bring about positive results sooner. This means sap values for both Ca and Mg coming into the optimum range before the end of summer. You've seen more than most as I shared last year's synopsis (formulation timing tied to actual sap numbers) for the South Block with the HON Advisory Board a couple weeks back. No, there are not any cultivated trees here getting no sprays whatsoever because there's no money to analyze what happens when humans are not involved with crop production. (Seriously, someone else can do that, if it would have meaning, which I doubt, based on most wild apples I've seen.) As for what makes for a quality fruit assessment... I'm seeing absolutely no bitter pit yet some who doubt these efforts apparently do. The most telling judgment may well come from a bionutrient analysis of the fruit itself by the Dan Kittredge camp. Stay tuned for more about that. I will certainly share research specifics from these extremely low budget efforts more thoroughly when I complete another year of homegrown trials when everything will gladly be shared through a big picture context. My kind of writing, in other words. Another underlying goal of all this work is mediating biennial bearing issues, and yes, I think gains are being made in those too frequent off years. Mostly I just wish there were more growers enthused about a nutrient-based approach to growing fruit versus the same old same old.

Let me drop the gauntlet back on you, brother... do an R2 sap test in your two apple blocks this year and let's see what your numbers reveal. Should everyone in this network do this, by gar, our conversations would finally move beyond this perpetual doubting thomas stage.

Lost Nation Orchard
Zone 4b in New Hampshire

As stated in an earlier post, my cost concerns with plant sap analysis are not really the cost per sample or number of samples per year aspects, but rather, the compounded costs of interpretation and subsequent nutrient application -- with an emphasis on the interpretation aspect; if I felt that my sap analysis results truly merited tweaking of nutrient applications, I would welcome any added costs of nutrient application (within reason). This past spring, when we were toying with doing our first plant sap analysis, we were planning to go with Apical Labs out in Oregon. Before ordering Apical's plant sap analysis kit, we spent time researching the sampling process and examples of reports. When we examined the sample reports, we knew that, for all intents and purposes, after excitedly sending off our leaf samples and ticking off the days, what we would receive back would be a gibberish of charts and figures to us, and we would necessarily have to rely on someone else's interpretation of our sample results. Apical has a great video on YouTube that walks you through an interpretation of an example plant sap analysis report regarding 'Honeycrisp' apple leaves: [www.youtube.com]. I just went back to revisit this, and thought it might help others to have a visualization, as well as accompanying explanation, as this discussion progresses.

Kordick Family Farm
Westfield, NC
Zone 7a



Edited 1 time(s). Last edit at 01/22/2022 04:25AM by Brittany Kordick.

There are many ways to skin a cat. Apical Labs does this gradient approach with lots of visuals, which maybe seems appealing... but its absolutely more complicated than optimum range targets and overall trends. That video makes my head hurt, Brittany! Still, there's things to be learned everywhere.

That leaf pH target of 6.4 refers back to Bruce Tainio's chart that below that value you'll see increasing disease pressure whereas a higher number indicates stronger likelihood of pest issues. What you actually want to see with both ammonium and nitrate readings are nearly undetectable numbers as this represents amino acids being converted to total nitrogen (which is the N reading that counts) and thus in complete protein form. The construct of new leaf and old leaf comparisons has merit in knowing whether reserves are in place for mobile nutrients. It was also interesting what David Knaus of Apical had to say about about sulfur imbalance from overuse of fungicides.

The results provided by NovaCropControl in the Netherlands and refined by Advancing Eco Ag (under the guise of Crop Health Labs) are far more amenable for grower interpretation. New Age Labs in Michigan purportedly provides a similar analysis but I have not seen one of their reports. Texas Soil & Plant Lab analyzes "midway leaves" rather than both new and old, and while the units appear different, there's a straightforward rating system of deficient /marginal/ optimum/ excessive.

The big takeaway in my doing this research over the course of three full seasons and learning how to interpret sap analysis in the context of soil constitution... is I'm going to write everything up in a friendly way so fruit growers can readily interpret results themselves.

All of which leaves me wondering why we're even skinning all these cats!

Lost Nation Orchard
Zone 4b in New Hampshire



Edited 1 time(s). Last edit at 01/26/2022 01:08AM by Michael Phillips.

It sounds like the sap analysis approach is targeted at reducing bitter pit and biennial bearing, as well as perhaps improving fruit quality (I would not use the Bionutrient approach to evaluate that).
That gives me something to work with.
On our farm, bitter pit has been a difficult problem on some varieties. If doing an R2 sap test (6 weeks after petal fall?) will help solve it, I'm up for it. I assume that I'll get recommendations for a changed spray program from it.
The proper control will be not to abandon spraying on some trees, but to use the unchanged "normal" spray program on them. This allows you to know whether the "new" changed spray program made a difference. In our case the treatment and control trees will both be Idared, which has a bitter pit problem here.
I'll probably send samples to 2 labs to compare analyses and recommendations.
Brittany, thanks for the video link!
It does not look to be cheap, but if it can reduce or eliminate bitter pit it will be worth it.

Hemlock Grove Farm
Zone 5 in New York

Brian's talk of his potential controlled experiment in his 'Idared' block got me thinking:

Glad to hear there are plant sap analysis frameworks that are simpler for growers to digest (although, I'm hoping and assuming that the raw data are still provided for reference and qualified growers' or consultants' interpretation, rather than just the companies' assessments as to whether levels of nutrients are "deficient/marginal/optimal/excessive"). It would be very interesting to send the same samples (or since some companies apparently use new and old leaves, while others specify different growth stages, to send samples from the same trees at the same times) to all of the handful of leading companies currently conducting plant sap analysis and compare the results/recommendations. But of course, that's just a doubting Thomas musing, and would be most appropriate not for any of us as individuals to fund and process, but perhaps for a large-budgeted agricultural publication to undertake on behalf of growers. I've emailed some publications with this suggestion. At any rate, I would be very curious to see how consistent the different companies' results are across the board. For now, this comparison of the different labs' approaches is the best I've been able to find: [www.soildoctorconsulting.com].

I'm also wondering how universally appropriate plant sap analysis interpretations could be in an orchard like ours, which has hundreds of different varieties. Obviously, varieties have somewhat specific needs, propensities and susceptibilities, and we certainly can't test them all individually, and by and large, we don't single varieties out for special treatment, in any case. It would certainly make sense to single out varieties for testing which have had specific issues you want to address, just as Brian is hoping specifically to address the historical bitterpit issue with his 'Idareds.' However, if we were hoping for more of a holistic snapshot of the orchard at the time of sampling, I'm wondering how variable results might be across varieties.

Kordick Family Farm
Westfield, NC
Zone 7a



Edited 2 time(s). Last edit at 01/24/2022 07:02PM by Brittany Kordick.

Lots of great info posted here since I asked my question about when to pinpoint the cell division phase.
This is the first chance I'm getting to issue a proper Thank You to everyone who chimed in.

Also gives me an opportunity to say to Michael I was excited to see you announce your orchard is thriving in recent years! It's really inspirational to know that all the time and effort you, and by extension your readers, are putting into growing fruit trees naturally and holistically really does pay off. I'm still getting my feet under me with all the information to digest, but reports of others' success with the program inspires me to keep at it.

So, thanx again!

Craig Bickle
Hap Woods
Zone 6a
East-Central Ohio

Thanks, Brittany, for the soildoctor link. It was most helpful in indicating to me where I fall on the continuum of holistic growers who might benefit from directly utilizing plant sap analysis to modify their management efforts. I'll be enjoying intelligently tinkering with my small, variable orchard plots without taking sap samples. That said, I'll be monitoring what the ongoing sap analysis research by others reveals.

Finally getting back to the mixed varietal question.

Big Ag speaks through grower magazines filled with glossy ads for a chemical mindset. (Yes, there will be organic options presented as well but we must never forget the mindset). The conventional realm taking up 'plant sap' is going to microanalyze results for specific varieties planted in sizeable blocks. That makes sense, given the scale of such plantings and the investment in the one variety to rule them all. Gollum.

I too have dozens of varieties in interspersed blocks, about 360 trees in all. Testing certain varieties in back-to-back years has allowed me to hone our collective understanding of what's going on with nutrient levels in the context of holistic management. I chose to test Sweet Sixteen in my north block, Bonkers in my south block, and will add Liberty in the east block this coming season. The tank mix for each block can readily be adjusted for spray comparison purposes. There's 2 to 5 trees of each of those varieties from which leaf samples are taken. Varietal consistency is important, I think, as genetic influences will be reflected in any sort of leaf testing. And while in an ideal world, I should be testing the very same variety with respect to three varying spray treatments, I am a grower trying to make a living first and a low-budget researcher second. Still, I have selected trees with similar growth habit, rootstock vigor, and harvest timing in ground treated much the same over many years.

The point here is one can extrapolate nutrient trends across an orchard planting from results for one chosen cultivar. My recommendation is for growers to choose a representative variety that produces decently in order to gauge 'site constitution' with regard to nutrient uptake... and use what's learned to tweak specific spray applications (as regards timing based on lessons being learned about nutrient pulsing). One round of sap testing at the end of the cell division phase provides a sense of seasonal suggestions for the next growing season. Three rounds of sap testing in the same year (as I am currently doing for research purposes) allows more refinement. My thinking is that either way a 'sap savvy grower' can now extrapolate happily into an ever uncertain future as regards specific core nutrient needs determined by site biology and soil reserves. Add in an appreciation for arboreal dynamics and you'll be doing better than most.

Lost Nation Orchard
Zone 4b in New Hampshire

Hi Brittany and all,
Let's continue this conversation. I wrote up a piece on sap analysis for this issue of the Community Orchardist--hope I did it justice.
Please share your thoughts!

Hemlock Grove Farm
Zone 5 in New York

Thanks Brian and Don for picking up Michael's plant sap analysis ball and running with it. For those who may not know, Brian and Don have been researching psa pretty hard for the last couple of weeks and spearheading an effort to figure out if there might be options to do some group education or collaboration on psa. Before Michael's death, we had more or less decided to try it this season and have Michael interpret our results. We were planning to start sampling at bloom (and we're at bloom!), but knew we would have a hard time trusting anyone besides Michael with the interpretation part. In looking for alternatives, we discovered Crop Services International (found under the Resources heading and Advisory Services listings of groworganicapples.com) and talked to Dane Terrill there a few days ago. Dane worked with Michael and was helping guide him through psa this past year. We had a great conversation, and it sounds like he would be an ideal person to give a group of us a sort of learning session surrounding plant sap analysis in general. He said he would be glad to do this in a very general sense, pre-sampling, or tied to a specific set or sets of results from one or more of us.

Per Michael's recommendation to start sampling/testing at bloom, we were concerned that we needed to get on this asap once we select a good representative variety. Since I know psa is generally dealing with samples of old and new leaves, I asked Dane how this would work on an apple tree in bloom, which doesn't necessarily have old leaves to speak of. He said this is an issue he's dealt with on a number of perennial crops, and while it's possible to sample/test just these new leaves, he's sort of backed off this approach over the years (unless you truly are micromanaging your crop and looking at tighter intervals at higher frequency throughout the growing season) since without the benefit of comparison of older to younger leaves you're not really getting the best value of psa testing. He recommended waiting until there are discernible new and old leaves, especially for a first-time tester looking for more of a baseline across the board, probably closer to petal fall. He said he had talked with Michael at length about how to best choose a representative variety, and that for this early season test, definitely pick a mid-season bloomer, not an outlier early or late one (unless, like Brian, you are targeting more of a troublesome variety, regardless of how it relates to the rest of the orchard). So it will probably be more like two or three weeks before we send something off for testing.

Dane said we would work with our chosen lab(s) directly and just make sure we put him down to have our results shared with him on the paperwork. He said he'd appreciate a head's up when samples are sent off, just so he can keep an eye out for results and keep in mind that a timely interpretation would be needed. Like Michael, he said he was open to interpreting test results from any lab, but that he was most fluent and experienced (and confident in the results of) those coming from NovaCrop in the Netherlands. He stressed that he did not want to push anyone to use one company over another, that he had the highest respect for Apical Labs' data, he just hasn't seen as much of it, and that New Age is kind of the new kid on the block (and thus, while they have a good reputation, he just hasn't seen enough to formulate an opinion about them), versus NovaCrop being the pioneer in this field and the lab he's worked most with from the beginning. The drawbacks of working with NovaCrop are really two-fold: slightly more expensive shipping (must overnight a sample to Ohio, then that sample is shipped on to the Netherlands, but care must be paid to make sure the logistics work out since shipments to the Netherlands go out only two days a week) and extended turnaround time (again due to the shipping time). It might be two weeks between sample and results via NovaCrop, and mere days via New Age.

I asked him about sample integrity if logistic issues arose, i.e., suppose a shipment of leaves gets caught up in customs en route to the Netherlands, would the lab reject the sample or would results be skewed. He said that there have been rare instances when the lab decides too much time has elapsed for the testing to have much value, but that if a sample does get held up, both the lab and consultants like himself are accustomed to how results might be skewed (most commonly, ammonium values will skyrocket if leaves start to break down) and can interpret just fine, accordingly.

As far as cost, he said that as far as he knows, most labs are consistently in the range of $85-100 per sample (really two samples: old and new leaves, but charged as a single sample) tested, and this has been what I've seen in my research, as well. The cost is compounded, of course, by shipping, and then by his consulting fee, which is charged by the hour ($75/hour) rather than per sample. He said that he typically would spend a half hour or so writing up a response to sample results. For some people, that's enough. For someone new to the whole shebang, he would expect to follow up with a phone call lasting 30-45 minutes that first time, and after that, to routinely spend 15 minutes on a post-report phone call.

We talked a bit about sampling specifics, that you need to make sure you get enough leaves, and obviously, the number it takes to achieve proper volume varies depending on sample time. Basically, you want to fill a 1 qt. plastic ZipLoc bag about 1/3 full of condensed leaves, or about the volume of "a 12 oz. soda bottle" for a more concrete visual example. You need to sample before 9 am. You need to sample consistently, from the same trees throughout the season and from the same side of the trees, as well, believe it or not (if it's from the north side, stick to the north side, if south, stick with south, as sunlight exposure has a huge effect on results (sugars produced, etc.). NovaCrop, and possibly other labs, asks that you remove leaf stems as they apparently sequester nutrients differently than other parts and can skew results.

So we're planning to move forward, and feel much better about this psa deal in general after speaking with Dane. At the very least, it's a tool we expect to be comfortable using in the future for specific issue testing (I recently posted about our apple measles diagnosis, which may be related to manganese toxicity; psa can help us understand what manganese levels are showing in the trees, rather than just the soil). I asked him about different labs and how I had wondered about sending the same sample to five labs and looking at how results might vary. He said that he has done that to some minor extent, i.e., send a sample to two different labs, and that he's found that, while extraction processes may vary, that results tend to be pretty consistent.

Anyway, he's a very frank and agriculturally well-rounded individual and seems like a good surrogate for Michael as an interpreter. It sounds as though Michael typically used NovaCrop for his lab, and then consulted with both AEA and Dane post-results (or perhaps switched from AEA to Dane). At any rate, Dane said he talked to Michael several times last year post-psa testing and their calls usually lasted an hour and a half. At this point, we're planning on probably using New Age Labs just because of the shipping logistic hassle of using NovaCrop. We're happy to be guinea pigs and report back on our experience in a few weeks!

Kordick Family Farm
Westfield, NC
Zone 7a



Edited 1 time(s). Last edit at 03/28/2022 07:00AM by Brittany Kordick.

Thanks, Brittany for summary.
For any HON following this discussion, if you are interested in wading into sap analysis there's an opportunity here as a group. New Age analysis costs go down to $70/analysis if you buy a package of 10 tests. And Dane is willing to conduct zoom consultations. Thus we'd all save $ on learning the basics of how to interpret these.
I'm willing to front that $, as long as there's a committment from the number necessary. I would plan on using three of those tests, so there's 7 to go... Let me know pronto.
Also, FYI, John Kemp and Advancing Eco Agriculture has been perhaps the biggest advocate for sap analysis. Their army of consultants do this regularly--but....it's expensive and they push you to use their products (also expensive!). Noticed they now say they "develop systems for large-scale regenerative agriculture." Don't know if that's us. All that said, there's lots to learn from John's approach. I'd go so far as to say that he and Michael were on the very same page. Just that John was much less of a purist and unwilling, as Michael, to take the risks that implies.
The other thread worth noting here is that in speaking with Dane Terrill, he said he's worked a good bit with Elaine Ingram (Soil Web). That certainly leads right back to innovative biological approaches based fundamentally in soil health and the mychorrizal sphere, if you will.

P.S. Just spoke with Dane Terrill from Crop Services International. He's willing to do a "module" with visuals and all, on sap analysis via zoom for 30-90 min to bring everyone up to speed. We'd all share cost, thus $40-120/??. Might be the way to see if you want to start into psa.
Anyone interested? don@kretschmannfarm.com

All right, the plant sap guinea pig has landed. We ended up sending off a sample earlier than intended in order to troubleshoot a specific orchard issue. Because none of our trees have distinguishably old vs. new leaf growth quite yet, we were not able to do a comparative analysis, but rather, sent in new leaves only. We happened to be wanting a soil test for our site-specific troubleshooting, as well, so it was convenient that New Age Labs, our chosen provider, offers a package that bundles a single sap test with a single soil test. The charge was the same as for a two test (old vs. new leaves) comparative analysis: $87.50 plus $50 overnight FedEx shipping. We happen to have lots of little ice packs, but bear in mind that you may need to purchase ice packs to send with your shipment, as well. We spent an hour and a half talking with Dane Terrill at Crop Services International about the results, but we had a lot of questions and were also troubleshooting a specific issue.

From the top, the sampling: it took me about 30 minutes to pick what I thought was enough leaves for a sample (I actually picked exactly twice as much, so should have taken about 15 minutes; if they were older, larger, less tender leaves, would have been even faster). The shipping was a little bit of a hassle for us since we had to take the box 30 minutes away (New Age specifically told us that FedEx would not pick up this package from the farm, not sure why that is since we have had other FedEx shipments picked up once shipping labels are in the system). We dropped the box off at 10 am on a Wednesday; it was received at New Age almost exactly 24 hours later, and we were emailed test results Friday evening, 60 hours after sending.

What we got back was, unsurprisingly, gibberish to us, and would have been useless at this point without interpretation by the lab or a consultant (the lab charges extra for interpretation, fyi). However, Dane's intention is really to help us get to the point of being able to interpret sap test results ourselves, and it does seem conceivable. Some of the terms with associated values were unfamiliar to us: "electrical conductivity" measures the salts in the sap and indicates general fertility; early in the season, new leaves should register as low in 'EC,' in contrast to the warmer growing season, when more nutrients move through the plant; the "K/Ca ratio" is just the literal comparison of your potassium and calcium ppm numbers for a quick assessment of whether these important cations are at the optimal ratios at different growth stages (bitterpit occurs when you have too much K and not enough Ca, for example, and you would be able to see your basic risk level at once via the K/Ca ratio). Most of the things being tested indicated the high-low ranges the lab was working with when assessing whether amounts were low, optimal or high, however, some, such as nickel, selenium, cobalt, aluminum, nitrogen from ammonium or nitrate, had blank spaces instead of range parameters. I asked about this, and Dane explained that in these cases, the lab has refrained from making a judgement -- they simply don't know what an optimal level is in this case, so you just get the bare value to do with what you will.

As he had stated to us previously, Dane was not as familiar with New Age Labs' optimal ranges and how they had come by them; he works predominantly with NovaCrop in the Netherlands. As he perused our results and associated assessments of low, optimal and high, he frequently compared them with the optimal ranges specified by other labs. He stressed that this is really where the labs differ -- not in their bare data findings. So obviously, if you are comfortable, or become comfortable, assessing your own data without the lab telling you what you should think about it, the ranges don't matter as much. In the case of our calcium levels, we were shocked to see them register as 'optimal' bordering on 'high' in New Age's estimation and Dane was also surprised since it is very uncommon to see high amounts of Ca register in new leaf sap, and also because our boron levels were low (Ca and boron are affiliated and trend similarly). We would have expected them to be low. Dane disagreed with New Age's optimal range here (again, not the data results from the test itself) and referred to NovaCrop's optimal range, which was twice that of New Age across the board, and thus, actually would have resulted in a much lower assessment of the calcium levels in our sap if we had tested through NovaCrop. Still, our Ca levels were not bad for this time of year, and our K/Ca ratio was spot-on in any case for pre-fruitlet formation.

There were other surprising takeaways from our maiden voyage, and overall, it helped me to understand our own spray program better. I like to understand what I'm spraying and why, not just kneejerk apply something because somebody said I should. But chemistry and biology are weak spots for me, and I got some much-needed clarification on some key points. Admittedly, much of this clarification was due, not to the sap test results themselves, but to the general conversation surrounding them. But that may be reason enough for someone to at least give psa a try once -- to gain better general understanding via the whole experience. Also, I had heard that, while regular testing costs add up, plant sap analysis often saves growers money in the long run, since you often find that you're applying something that you may not need to be applying. So as an example of something important that we got out of this (the interpretation, rather than the test results themselves, though), we apply Sea-Crop in our orchard regularly throughout the growing season in small amounts ranging from 6 to 12 oz. per 100 gal per scant acre. It's been so long since we added this to our regimen, I had it in my mind that this was solely a trace mineral thing. Dane reminded us that seaweed products like Sea-Crop contain the plant growth hormone cytokinin, and while a big reason to apply them is to stimulate plants during times of stress, you probably don't want to be applying this stuff willy nilly. We will be doing more targeted applications in the future, so should be better for the orchard and this will ultimately save us some money, as well.

Also, we had recently cut AEA's Micro-Pak micronutrient blend temporarily out of our spring spray plan since we were concerned that we may have a manganese toxicity issue in our orchard and Micro-Pak contains Mn. Specifically, in terms of our Mn levels, we were at 6.44 ppm, considered below optimal; Dane said that if we were dealing with a Mn toxicity issue, he would have expected to see higher levels in the sap of new leaves. What we found was that, across the board, we are low on most of the nutrients found in a micronutrient blend like Micro-Pak. I asked Dane why this might be, since we regularly apply micronutrients, albeit with the understanding that the amount we are typically applying, 32 oz. per 100 gal per scant acre, is not enough to really move the needle on accumulations in the environment (and certainly not enough to toxify it), but rather more of a "tonic" dosage, to use Michael's phrase. What I did not remember or understand is that applying these seemingly almost ridiculous trace amounts of things like micronutrient blends at certain times stimulates the trees to take them up in greater quantities from the rootzone. In terms of remedial action, our sap results are pleasing in that we don't appear to be in need of a great deal of balance within complicated antagonistic nutrient relationships (if something is in excess, it can cause something else to be deficient, for example) -- across the board, with one notable exception that follows, we would just like to see higher levels of micronutrients in general.

Relatedly, we were shocked and somewhat pleased to see that we had 'high' total nitrogen of 1010 ppm (immediately usable proteins in amino acid form that the plant does not need to break down for use, rather than N from nitrates or ammonium) in this new sap. We don't currently apply fish products or anything else containing nitrogen in our orchard and North Carolina soils are notoriously low in nitrogen (according to our state university, which does not even routinely test for N in soil, just gives you a recommended app rate), so we would not have been surprised to see a very low result here. Dane was not surprised, given our emphasis on healthy soil and canopy biology, explaining that if the soil biology is in good shape, most perennial crops can find what nitrogen they need without supplement.

We had been concerned at the increasing copper accumulation in our soil after years of dormant copper use, particularly the cuprous oxide formulation we favor that sticks around in the environment longer. While we were nowhere near levels of toxicity, we did not like to see our copper levels steadily climb in our soil test resuls, and had decided not to apply any copper for a while. So it was nice to see that the copper levels in our sap were low bordering on optimal, and Dane indicated that, following comparative plant sap analysis results, he would not be surprised if he even recommended we apply copper specifically to bring levels up more.

We will be following up this new-leaf-only test with comparative plant sap analysis tests of old and new leaves in both the variety we are troubleshooting, as well as a general variety that can better represent our orchard at large (we have tentatively chosen 'Roxbury Russet'). We will be applying a general micronutrient blend twice before we do that, in order that we can assess the effects of this application on our nutrient levels; we expect to test again in about two weeks. This is an example of how plant sap analysis can help you fix a problem before it starts -- by testing an early blooming variety now, we will be able to correct potential deficiencies in our mid and late season bloomers while it can still make a big difference. So overall, this plant sap analysis thing was a good experience. I'm glad to know how to use another tool in the event that we do need to troubleshoot specific issues, and it was definitely helpful to understand that we should keep including a micronutrient blend in our situation, at least in the short-term. I doubt plant sap analysis will be something we do regularly in perpetuity, but yeah, I think it will be helpful to better understand and target our spray program and better anticipate our trees' needs in the future.

We think it's way too simplistic to strive for perfect nutrient levels in your plant in the belief that your plant will be perfectly healthy as a result and not susceptible to disease or pest pressure. Our understanding is more that by trying to optimize nutrient levels in your plant at the right times you're setting yourself up with the best possible odds for success (if you get a hailstorm, you're still at risk for fireblight infection; in our climate, we are always going to be battling fungal rots, but the trees will be in the best possible health going in, and that should help in the long run). So no silver bullets here, not that most of us expected any, I don't think, but a useful tool. For anyone else concerned about dispelling any of the magic and art of orcharding via the micromanagement inherent to plant sap analysis, be assured, there is plenty of mystery left out there and we are pleased to see both labs and consultants very straightforward about what they don't know or understand. At some point Dane said something about plants being ultimately a lot smarter than we are when it comes to their own needs. If anything, we came away from our initial plant sap analysis experience more humbled, and did not feel pushed to buy tons of new products or test, test, test (quite the contrary, actually). Anyone wanting to see an example of plant sap analysis results from New Age Labs, feel free to email us at cheers@kordickfamilyfarm.com.

Kordick Family Farm
Westfield, NC
Zone 7a



Edited 1 time(s). Last edit at 04/12/2022 11:20PM by Brittany Kordick.

Hello there,

Jumping into this conversation late... we started working with AEA this past summer - pricy is right - to try to finetune some areas of our nursery. We propagate around 150 apple varieties + plenty of pear and other species, this summer we've been getting sap analysis done for old and new leaves in different crops of apple, pear, sweet cherry, as well as some trees in our test orchards. Not keeping cultivar specific since we specialize in different varieties and we wouldn't have enough tissue sample (around 20 000 trees total), rather aiming for a more broad wholistic management approach. Can confirm, the mystery of trees is fully maintained despite analyzing the sap

Our goal is to just solve some issues we have - one example being peaches: I can bud them in Aug, they take and have clearly callused and healed well. Over winter in early spring they still look good. Then spring does it's freeze that routine, we madly scramble with orders and the 'selling' part of the nursery, then when we get back to the fields in late spring/early summer, many of the grafts have failed. In talking to a wholesale nursery, they said they heap soil to cover their graft unions over winter, essentially hilling their peaches. If AEA fails, I guess we will try hilling them, but it's frustrating to try year after year to grow them (they grow in the test orchards fine) but not be able to reliably propagate them (the odd spring with perfect weather they are fine). My understanding is calcium is needed to increase the plants hardiness... we will see how things overwinter this spring...

A point of interest with AEA - I have no idea if this will pan out - but I am hoping with input from the AEA rep we work with (who said he wanted to help us towards our goal of not using their products/outside inputs in the long term), and by extrapolating the information from Nigel Palmer, folks here, etc, and plenty of trial and error we can more or less grow/brew our own potions... however this journey seems to have a very very long road ahead of it!

Don: any chance that zoom was recorded? I'd be interested to view if so.

Thanks,
Steph

Silver Creek Nursery
Zone 5 in Wellesley, Ontario

This is a great discussion. Perhaps folks who have experience with SA can relay differences they found between it and tissue analysis for determining plant health or problems. John Kempf explains his motivation for adopting SA as a primary tool was his company's frustration with dry matter TA results. Are we seeing this out there in our orchards? Are growers frustrated with TA and soil testing as tools?

I'd love to hear some feedback from growers that use both regular dry TA and sap analysis as a comparison. Personally I've felt the arguments for SA to be a little disingenuous, even though I believe the concept is solid. As well, there has been cost of testing + materials, delays in getting results, and lack of supporting data (even some reps have been fairly forthcoming, AEA has not). I can say that the growers I have used SA with (incl my own orchard) have found it less than useful or cost effective. Lastly, and just from a principles standpoint, SA has seemed awfully reductionist and counterintuitive to a holistic approach. Whenever I think of SA I see an old school computer with lots of dials, buttons and switches where we're trying to tweak something to the point of no return. Is it really worth it or shouldn't we step back and truly look at things from a macro standpoint? On the other hand, the microcosm is a reflection of the macrocosm (in a biod sense) so perhaps there is a way to approach this without being too reductionist. For example, knowing there is a Fe deficiency is important. But to what level of detail do we really need "to know"?

Mike Biltonen, Know Your Roots
Zone 5b in New York

Thanks Mike,
I agree with you 100%. Four of us HON folks coordinated together and sent in leaf samples for plant sap analysis (PSA) this summer. We interpreted the results with the help of Dane Terrill, a consultant. The results were instructive, but I have the same reservations.

I took the project in a different direction and sent subsamples of the same batches of leaves to 3 labs--New Age (PSA), Apical (PSA), and Dairy One (standard tissue analysis). I'm in the process of writing up the results, however, some quick takeaways--the results were reported on 3 totally different scales, so they could not be directly compared. They were mostly in agreement as to which nutrients were deficient/optimal/excessive, with a few major exceptions. For instance, Apical and New Age considered my potassium levels to be low, while Dairy One said they were high. Apical found that my sodium and chloride levels were excessive, and New Age said optimal.

However, they all agreed that my micronutrients were low. Dairy One only tests for a few, but the other two labs lest for many. I thought it was wise to get a micronutrient mix and put it on a few times. I can't tell if it helped from this year's crop results since I sprayed everything, but I'm pretty sure it didn't hurt. Having the PSA results helps me justify those sprays to my organic certifier.

The other folks did multiple PSA tests over the summer to see whether their targeted nutrient sprays had the desired results. My take is that it is hard to interpret those later reports.

From correspondence with Michael P before he died, I believe that his goal for the next book was to use PSA to guide sprays of farm-fermented nutrients at specific points during the season. He seemed pretty clear on when those points were, but was investigating whether his ferments could "bump up" nutrient levels when sprayed at those times. He was not skeptical of PSA methods and results, and felt he could use them reliably to observe this sort of response. As we would expect from Michael, he very much wanted to find out how to supply nutrient needs from on-farm, biological sources as much as possible--hence the work on ferments. And as usual, Michael was way ahead of the curve.

Hemlock Grove Farm
Zone 5 in New York