Integrated Nutritional Management for Quality and Bitter Pit Resistance in Pome Fruit Production

Good evening everyone. So the context for this conversation and wanting to speak about apples and apple discussion. We've had some interesting observations over the last couple of years as we work with apple growers through the Pacific Northwest and in the Northeast and the Great Lakes Fruit Belt region throughout New York and Michigan and Ohio. So there's so many correlations between disease and insect resistance and nutritional profiles that I wanted to talk about. I was asked to present some of this information by Cornell University to a group of their growers a couple of weeks ago and had very strong feedback. They asked me to ask you to come back and speak again. And so we wanted to share this information with you as well. Some of the things that we've observed and that we've learned. So going to go through fairly rapidly some of the nutritional correlations that we've learned and observed to fruit quality and disease and insect resistance, how we've been able to observe them. And the foundational piece that I'll be working from tonight and talking about will be the path that we have been on since 2011. So brief history, my personal history. I grew up on a family fruit and vegetable farm in Northeast Ohio where We had a three year crisis period from 2002 through 2004, three consecutive crop years where we lost over 70% of our production. And as a result we had some very interesting experiences on the farm. One being that we had a new field that we had just started farming side by side with an old field that we've been farming for the last decade. We planted these two fields into cantaloupe on the old soil that had a history of very intense pesticide exposure and applications. At harvest time we had 80% leaf infection with powdery mildew. And on the new soil there was no powdery mildew, even though with the exact same variety plant of the same day, same nutrition, same fungicide applications, we got two completely different plant responses and that that really led me to want to understand what are the differences between these two plants and what allows one plant to to be resistant to the powdery mildew when the next two feet away is susceptible. So from that I spent a lot of time from that initial question, I spent a lot of time studying and researching agronomy and plant physiology and botany over the course of the next six months year. And I spoke to people from within academia and usda and what I learned is that plants have an immune system and they have the capacity to be completely resistant to diseases and insects. And I discovered that there's an entire bit of Research around disease and insect resistance that is correlated with mineral attrition that we don't commonly talk about in agriculture. This eventually led to the founding of Advancing eco Agriculture in 2006 and we become very well known for we could growers grow crops which are resistant to disease and insect pests based on how we manage nutrition. However, in in order to manage nutrition effectively as we work with growers, our the tool that we used was tissue analysis. We would collect tissue analysis samples from fruits and from leaves during the growing season and prior to. Well from the period of 2000. Starting from 2008 onward, we were typically collecting in the neighborhood of 10,000 plus tissue samples per year. So we had developed a pretty substantial database of what different fruit and vegetable crops were looking like throughout the country. And using tissue was a very frustrating experience because there was an abundance of research pointing to specific nutritional correlations to specific diseases. If we think about powdery mildew, for example, there's likely in the neighborhood of 40 references describing how powdery mildew is associated with low levels of manganese. And yet on the tissue analysis data we were never able to correlate the presence of powdery mildew with low levels of manganese. So from this fraction frustration I expressed my frustration in late 2010 to my colleagues and mentors. Arden. Anderson and Arden suggested that we look at a new technology that was being developed in the Netherlands that was called that they were referring to generically as SAP analysis. So SAP analysis was completely different from tissue analysis in that when we collect the tissue analysis sample, we send it to the laboratory, they ash it and completely dehydrate the leaves, then measure and report the minerals that they find on a dry matter basis. With a SAP analysis, we're sending a fresh leaf sample from two locations on the plant, from the new growth, from the last fully mature leaf on the shoots and then an old leaf on the plant, either a spur leaf in the case of apples and tree fruit, or sometimes the oldest leaf on a new shooter. By collecting two different samples and measuring them separately, we were able to identify how the tree was moving nutrients around within the plant SAP, which was very valuable for all the mobile nutrients, particularly nitrogen, phosphorus and potassium. NPK are quite mobile and the deficiencies always show up on the oldest leaves first rather than on the new leaves. So if we only collected a new leaf sample, we don't see the deficiencies until it's entirely too late. But the SAP analysis was really powerful tool for us because for the first time it correlated. It was extremely accurate. It was very sensitive and the needle moved very quickly. We were able to actually use SAP analysis to evaluate product performance in the field because we could put product application, let's say calcium, for example. Calcium is very relevant example for our discussion when we think about challenges with bitter pit. The challenge we have with tissue analysis is that as we know, the plant and the tree needs to absorb most of its calcium from the soil profile. That's what should be happening because the calcium is primarily transported by xylem. And what would happen is, is, let's say one day, we'll call it day zero, the soil is no longer able to supply all of the plants and the trees requirements for calcium on that day. Calcium level on the SAP analysis will go from 1500 parts per million to 500 parts per million. The needle moves backward very, very quickly. But with the tissue analysis, the tissue analysis would still show that we have adequate levels of calcium because it also reports all the calcium that is present already in the cell membranes, the last fully mature leaf. So we won't see a calcium deficiency showing up for another three to four weeks, depending on how rapidly the tree is growing. So it was very. The SAP analysis was very valuable because we were able to see nutrient interactions very quickly and we were able to correlate them with diseases and insects, presence of diseases in insects, which was very valuable. But more importantly, we were able to see how the tree was moving nutrients around and we began being able to correlate them with fruit quality and fruit uniformity, storability and all the fruit quality metrics that we care about. So I love this comment from William Albrecht. He said that read books and study nature and when the two of them don't agree, you throw out the books. And I believe that we should do the same thing with laboratory reports. If we were constantly getting these laboratory reports that were not correlating with what we were actually seeing in the field. And so we've ditched them and moved to SAP analysis. We've been using SAP analysis since 2011. We conduct tens of thousands of samples per year. We have a pretty extensive database and we've been able to see some very interesting nutrient correlations. So this is the nutrient interactions chart that was originally developed by Mulder describing all the antagonistic and synergistic relationships within plants, within nutrient interactions with plants. It's a very complicated chart. There's a lot of information here. Should have memorized all of it already. Just joking. Nobody's memorized this chart. The team in the Netherlands that developed SAP analysis developed their own chart, which I then modified to make it easier to understand based on how they observe nutrients interacting. So in this chart we have, this is the chart that they developed. And there's a lot of information here. I'm in the process of producing an online course to describe how we see nutrients interacting with. But let's just say it very simply. In the upper left hand quarter, upper left hand quadrant of the chart we see that we have all the macronutrient cations. Calcium, potassium, magnesium, sodium and ammonium. What they observed was that each that plants have a finite mineral holding capacity for cations and that when one of these cations is in excess, it can have the effect of creating a deficiency of another cation. And they observed the same on the upper right hand quadrant that all the anions were antagonistic and that then when there was the presence of an excess level of 1, it created a deficiency of one of the others. And we've observed this to be very true in the field, which is a powerful realization because within agronomy we have this idea that we constantly need to be adding more. We conduct an analysis, we find out what's missing, we, and we add something in addition, we add whatever is missing. And what we realized when we start looking at these nutrient interactions is that many times the challenge with nutrients not being absorbed well is as a direct result of excesses of products that we have applying, that growers have been applying. And the perfect example of this and what we first observed most strongly was the intense antagonistic relationship between potassium and calcium. This then led to the realization that particularly in the context of bitter pit, but in general, all of the calcium related physiological fruit disorders. When we look at blossom end rot on tomatoes or sidewall rot on peppers, bitter pit in apples. In many cases, the reason the trees and plants are not absorbing calcium well is not because there isn't enough calcium in the environment. As we know, many growers are foliar feeding an abundance of calcium. They're putting a lot of calcium on the soil profile and they're still not getting good absorption of calcium from the trees. And the reason is not that they don't have enough calcium, it's that the trees, and this is particularly true of Braeburn and Honeycrisp apples for that matter, all the varieties which are very prone to bitter pit, these varieties have a genetic predisposition to hyperaccumulate potassium. These high levels of potassium end up creating a functional calcium deficiency and preventing the tree from absorbing calcium. So this is an example of what a SAP Analysis looks like on a PDF report, you can see that we have two reported values. The upper one in light green, light green bars is the new growth at the top of the plant or the top of the shoot, and the dark green is the older leaf at the bottom. And the important ones that I'd like you to focus on is fifth are from the top we have total sugars, phec, then we have potassium and calcium, and then we have the potassium to calcium ratio. And for this particular variety, this would be what a typical apple variety would commonly look like, a ratio of about 6.7 and 7. So this is a very good ratio and it's what we're observing that in order to develop and make sure that we have low levels of bitter pit, managing the calcium potassium ratio is a really important piece. So altogether, we also measure ammonium and nitrate and total nitrogen, all these various elements all together, the entire range of trace minerals. A single SAP analysis measures a total of 22 different parameters. And this is an older analysis, the more recent ones. We also add specific desired values. And we've started measuring cobalt and reporting cobalt as well on all of our tests. So one of the things that we've observed also is that there's this entire concept that we've developed called critical points of influence. And this is also. This can be a very nuanced conversation. It's more than can do justice in a short conversation. But we've identified that when plants switch from vegetative growth to reproductive growth, there is a tremendous hormonal shift that, when that hormonal shift is supported, right, nutrition, it can give trees a great deal of disease and insect resistance and can have a significant impact on fruit quality. When it's not supported, we have a great deal of disease and insect susceptibility. So to give you an example of what I'm talking about, when trees emerge from dormancy in the winter and you begin the blossoming and pollination period, when all those blossoms pollinate on a tree in a relatively short window of time, it's the equivalent of a pregnancy, that entire tree becoming pregnant. And that facilitates a substantial hormonal shift. And that hormonal shift needs to be supported with the proper nutrition, in this case, particularly high concentrations of calcium, boron and manganese, amongst other trace minerals, as well as zinc and copper. And when that hormonal shift isn't properly supported, we have peak susceptibility to codling moth and to all the various insects and diseases that often get their start immediately after the blossoming pollination Period. Because that tree has switched from healthy to unhealthy, from protein synthesis to proteolysis mode. The entire point of critical conversation around critical points of influence, essentially the essence of that point is to say that it's possible to put on nutrient applications, foliar applications of nutrients, or in the fertigation system at critical windows. Sometimes when we apply them at a critical window, we can have a tremendous impact on plant health and performance. And at other points, putting on foliar applications of nutrients is going to produce only a very limited crop response. So here's the very important, very important slide. We've observed that there are differences between reproductive growth and vegetative growth and how this influences hormone profiles. You can see here we've listed cytokine and dominance versus auxin dominance, alkalinity versus acidity. And there can be a wide range of conversations about the influence of these various polarities, if you will, within agriculture ecosystems. But here's the foundational piece. It's possible to have a lot of growth without sacrificing fruit quality. And we need to manage specific nutrients and nutrient interactions in order to make this happen. There are four nutrients on the right hand side which give us very strong vegetative growth response. These nutrients are calcium, potassium, nitrate and chloride. All of the other elements have a reproductive response, phosphorus, led specifically by phosphorus and manganese and ammonium. So to give you an example of how we might use this in crop management, sometimes we work with growers who have plants that are dominated by vegetative growth. They're getting very rapid shoot extension, very long shoots. Sometimes this is a challenge in apples as well. We want to maintain short, short shoot growth so we can put on applications of these reproductive elements. An example would be on tomatoes, sometimes tomato growers through, for whatever management reasons, miscommunication reason, sometimes we see tomato fields that have had an over application of nitrogen. And we have tomato plants which are 3 and a half to 4ft tall, dark green, beautiful plants, beautiful foliage with no tomatoes. And that's because these plants have consumed and picked up too much nitrate. So to balance that out, we can put on a foliar application with a very high concentration of manganese and phosphorus. And it's possible on a tomato plant to turn that plant completely yellow. With flowers, in a matter of about 96 hours, four days, produce a very strong fruit set. So this becomes really interesting when we manage, when we think about managing tree fruit nutrition, when we look at these elements in managing reproductive dominance versus vegetative dominance, the healthiest trees the highest yielding and the most productive trees are trees that are reproductive dominant, that have a dominant root system that are dominated by cytokinins rather than auxins. They have really short internodes and all of these, the larger root systems, all these benefits. Looking for. Now if you notice, at the very bottom, I've listed that on the reproductive dominant side, the left side of the chart, we have plants that are dominant, cytokinin dominant versus vegetative dominant. Is auxin dominant? If we look at the top of the chart, nitrate, potassium, chloride and calcium all drive vegetative dominance. They drive vegetative growth. So if we want a tree to add a lot of biomass or any plant in agriculture, we can add any of these four elements to drive vegetative growth. So let's take alfalfa for example. If we want to grow a lot of alfalfa biomass, we can fertilize with my radiative potash, potassium chloride. And that combination of potassium and chloride gives us a lot of plant biomass very, very quickly. If we want to grow corn biomass or many other crops as well, we add nitrogen in the form of nitrate and that nitrate gives us biomass as well. But calcium is different. And actually, let me just clarify the reason. We have nitrate, potassium and chloride all have a synergistic relationship with auxin, but calcium is different. Calcium has a synergistic relationship with cytokinin. And so when we. So if we use calcium to get our growth energy, we can achieve the same amount of shoot growth, let's say on a tree we want to get 18 inches of shoot growth. We can get the same quantity of shoot growth with calcium. We can by adding nitrogen. But there's one key difference. Because calcium has a synergistic relationship with cytokinin, the internodes facing will be two to two and a half inches if we're calcium dominant. Whereas if we're nitrogen dominant, the internode spacing is going to be 4 to 6 inches. So you have much wider internode spacing when you have nitrogen dominance versus calcium dominance. Having high calcium content would. And getting our growth energy from calcium is how we can produce high carbon fruit wood that has a very strong future reproductive potential and super bearing potential. That's another conversation that we could unwrap more. One of the things that we've observed with SAP analysis is when we know there's some apple varieties that are resistant to scab and are susceptible. And a long time ago, probably 10 years ago, I read some research papers which correlated the presence of apple scab to the presence of high levels of asparagine, the amino acid asparagine. And I was able to identify that cobalt is the missing enzyme cofactor that allows trees to accumulate high levels of asparagine. And that when we put on foliar applications of cobalt, the tree metabolizes all the asparagine, moves it on to other peptides and proteins, and the result is that the susceptibility to apple scab virtually completely disappears. We've actually had quite a bit of field experience with this here in New York. And what we observed with SAP analysis. When we started conducting SAP analysis on susceptible versus resistant varieties, all of a sudden we observed that the correlation was the apple varieties, which were resistant to scab, were genetically much better at absorbing cobalt. They would have cobalt levels as much as three to five times higher than the resistant varieties planted side by side on the same soil. So there was actually a nutritional correlation and a nutritional foundation for the disease, susceptibility or resistance. The next thing that we've observed is we have observed a correlation to the presence of Bitter Pit and the potassium to calcium ratio. I referenced this earlier, but the key piece is not that we don't have enough calcium, but that we actually have a potassium excess that is creating a functional calcium deficiency. Our first experience with this was working with cherry production the Pacific Northwest, where we started looking at the stages of fruit development. After pollination. We have a 10 to 14 day cell division period which determines the potential fruit size and the number of cells that is formed during the cell division period, limited by calcium availability. And so we understand that future fruit firmness and cell size and the number of cells is all determined by calcium supply. And this cell division window is our golden window of opportunity. We want to move as much calcium as possible into the embryo at this stage. We understand that for many crops, including apples, assuming the apple is healthy and has a good potassium to nitrogen, or, excuse me, potassium to calcium ratio, 90% of all the calcium in a large mature fruit this big around is going to be in that embryo 14 days after pollination. So the ideal is to move as much calcium as possible into that embryo into immediately after pollination. The reason that often doesn't happen is because we have too much potassium at this stage, there should be no potassium applications. Early after cell division, we switch to cell expansion for the remainder of the fruit fill period, remainder of the season. And the cell expansion, of course, determines actual fruit size and is limited by potassium supply, because potassium is the element that is responsible for translocating sugars into the fruit. So this is honeycrisp apples before a foliar application. This is an example of honeycrisp's desire and propensity to accumulate potassium. So here we have on the old leaves, potassium levels approaching 8,000 parts per million. And we have a potassium ratio of 6 for Honeycrisp actually is not that bad. It's not uncommon on honeycrisp to see this ratio be as much as 2 to 15, which is where you see a lot of problems happening. So after this SAP analysis, we put on an application, foliar application, based on the results for this analysis. So the one key piece is that this is a continuation, the bottom half of the page of the analysis that you just saw. You look at manganese and boron levels. Manganese is very low and boron is very low. I haven't taken the time to describe the story of how we learned about potassium, but let me just say that we learned from looking at a lot of data and some field experience on tomatoes and other crops that manganese seems to serve as the potassium thermostat. It can both up regulate and down regulate potassium absorption in two key places. One is when you have a tree that is growing on a potassium rich soil, it can prevent that tree from continuing to absorb a surplus of potassium. And secondly, when you have a tree which already has an abundance of potassium throughout the entire tree frame, the trunk and the branches and everything else, then it can also prevent that potassium from moving from the tree frame into the embryo during that critical cell division window. So manganese is our tool to manage this genetic tendency to accumulate a tremendous amount of potassium. With honeycrisp and Evercrisp and Braeburn and other related alcohol tend to have these really high potassium accumulation levels. So if we look at these levels, manganese and boron were both low. Of course, we add boron or often look at boron, because boron is the synergist with calcium and improves calcium. And so if we look at the next slide, we'll see that we put on a foliar application of calcium, manganese, boron, and some other trace minerals. I think we added zinc and copper to this as well. And look at what happened to the calcium to potassium ratio. We added some calcium, we added boron. Our reason for adding manganese was so that potassium levels would drop. And potassium levels dropped down to 5,000 parchment on the new leaves and 5,700 on the old, and calcium levels went up. And look at what happened to the ratio, the ratio halved or doubled depending on your perspective. So we went from a potassium to calcium ratio of 6 to potassium to calcium ratio of 3. This is how you resolve the bitter pit challenge. If we look at manganese and boron levels, manganese went from I think it was 12 and 15 parts per million to 54 and 49. And boron levels are at 7 and 11. So both of these trace minerals substantially increased. And that is that we see this classical correlation. As manganese and boron levels go up, potassium drops, calcium goes up. So it's very strong, very reliable, very repeatable. In fact, I heard a story last week or maybe two weeks ago now when I presented this information in New York, I first published information about what we're observing with the calcium, potassium and manganese relationships in the American fruit grower. I think it's two years ago, maybe three years ago. I'm not entirely certain. A grower in New York read the article and didn't conduct any SAP or tissue analysis, didn't check his levels, just guessed about what he needed. And he put on bi weekly foliars once every two weeks. Foliar applications of a chelated manganese. And he ended up creating a potassium deficiency. Well, not actually a potassium deficiency, but he ended up creating such low levels of potassium in his honeycrisp apples on the test block that he was experimenting on that his apples were only full market size and they didn't color very well. So that's an indicator that manganese and he had no bitter pit completely fixed. His bitter pit probably had no bitter pit whatsoever. But he also had about 50% of a marketable crop. So that's evidence that the manganese applications work very well. But you can't guess. We have to test, we have to measure and know exactly what the tree's requirements are and not put on more than what they actually require. The Plant Health Pyramid is a diagram that I developed. I just put together. We had a webinar about the Plant Health Pyramid a couple weeks ago. If you're interested, you can look that up and find it on YouTube. Essentially, the plant Health Pyramid is a diagram that I developed to describe how observed disease and insect resistance be happening in a number of different crops that we've worked with foundationally. We've observed that at different levels of physiological development, trees become resistant to different groups of insects and diseases. So the first group, the bottom of the pyramid. When plants and trees have complete photosynthesis, they become resistant to all of the root diseases, the soil borne fungal and bacterial pathogens phytophthora verticillium, rhizoctonia, etc. Pythium at the second level, become resistant to all the larval insects and the insects with simple digestive systems. So Colling moth leaf miners, leaf rollers, spider mites, aphids, etc. The third stage, when plants begin forming higher levels of lipids and higher levels of fats and oils, we have this glossy, waxy sheen on the leaf surface. Plants become resistant to the airborne fungal and bacterial diseases such as downing powdery mildew, rust scab, etc. And at the fourth level they become resistant to the beetle family, Japanese beetles, Colorado potato beetles, marmorated stink bug, and so forth. And there's two hours of conversation and science behind this diagram. It's too much to get into right now, but if you want more information about what we've learned about that and specifically what to do and what nutrient interactions to manage, I spoke taught a webinar I think two weeks ago on this topic that has been posted on YouTube and there's also a detailed infographic that you can download from the Advancing Eco Agriculture website that gives all the information that we have learned about how to manage plant health. So I want to say thank you to all of you who participated. You found the information useful and valuable. If you have any follow up questions, feel free to reach out directly to Jim and or to respond to Anna. I'm happy to have any follow up conversations with you directly on a one on one basis as well. Have a wonderful afternoon evening and I'll speak with all of you again soon. Thanks everyone. Be well.