Managing Vascular Bacterial Infections

Hi friends. Welcome back to this webinar hosted by Advancing Eco Agriculture. I'm John Kemp, and our topic for today's webinar is how to manage vascular infections. These are bacterial infections that occur inside plant tissue, some of them inside the phloem and xylem, and then some of them in case of diseases such as bacterial canker on stone fruit, actually occurring in outside the cell cytoplasm and throughout the entire tree structure. So managing these Diseases There are many diseases on a broad variety of different crops that are that function in this way. Xylella fastidiosa is known as Pierce's disease in grapes, but actually is the causative organism for over 500 different diseases and different crops worldwide. And it ranges and includes citrus greening and gosses wilt on corn, sudden death syndrome and soybeans. There's kind of this really long list of various different diseases that can cause significant crop damage and historically are very difficult to manage with pesticide applications because there aren't very many particularly effective treatments known to treat these diseases inside plant tissue. We've had some interesting experiences over the last decade and we've learned a lot in the last few years about what allows these diseases to express themselves inside plant tissue. And so when we first put this topic together for this webinar, my idea was to share and describe what we have learned with these different diseases and to say that, okay, if we have Pierce's disease, then we can address manganese and we can address the form of nitrogen that we're managing and give very specific recommendations for specific groups of diseases. But as we started putting the information together that we wanted to share in the webinar, I realized that putting together those specific recommendations without the historical context, without the background knowledge and information really would make. It's not that it would make no sense, but there would be lots of missing dots. And so the topic for discussion today is not so much going to be if you have X disease, apply these five nutrients. Although we certainly are going to talk about some of the nutritional profiles that are present. But instead I wanted to focus on the background historical context of what are the nutritional parameters and what are the environmental factors that have to be in place in order for these diseases to become really virulent and really express themselves very strongly. I think information that we're going to be discussing on this webinar, for those of you who have heard some of our information in the past, is going to be somewhat familiar. But I hope to connect the dots, particularly for these diseases, in ways that they may not have been connected quite before and to describe the environmental and nutritional context that is required for these diseases to really express themselves. So without any further ado, I'm going to dive right in what I realized, as in our consulting work at Advancing Eco Agriculture over the last decade, we've had some remarkable successes in reversing infectious diseases that are supposedly not reversible, such as bacterial canker on cherries, which is one of the stories that I want to share today. But many of these vascular bacterial infections are, for lack of a better analogy, they're considered to be the cancer of different crops because there is no particularly effective treatment for that is widely known. And yet in some cases we have observed these diseases to completely reverse themselves and stay reversed for years and never. And in fact, in some cases we now have about eight, I think eight, nine years of experience where they have never returned. So we can't say indefinitely because we don't have that much experience, but they haven't returned for long periods of time. And the reason, the way that we were able to manage these diseases was not through a pesticide or fungicide application, but through changing the nutritional environment and the redox environment within the plant. So I want to offer some context for how that functions and the flow. And I'm going to be framing the conversation, the webinar today around these four primary diseases, Xylella fastidiosa, which grape producers know as Pierce's disease. But it also is the causative organism for over 500 other diseases globally. Bacterial canker, pseudomonas, syringia, crown gall and walnuts, Agrobacterium tumefaciens. And then of course, the wonderful citrus greening. The information that I'll be talking about about how to manage these diseases is not just specific to these four. I'm using these four as specific examples with information pulled from the literature. But the concepts really apply to all of these vascular bacterial infections. I also would like to point out that what I'll be speaking about today is not there has been some new science and new information that has emerged in the last couple of years. But really the important thing that I have learned from Olivier Hassan and from others in looking at these nutritional parameters for diseases is not so much new information, but looking at the historical information, looking at the historical science through a different lens, looking at it through a different framework, and gaining new insights from connecting the dots of what this nutrition, these nutritional profiles mean, particularly in the context of understanding redox and the biophysics environment that is present within the xylem that is present within the phloem and that is pleasant throughout the plant's entire vascular tissue. The context for thinking about diseases in this manner is really thinking about insects and diseases as nature's survival of the fittest mechanisms. They are here to take the unhealthy plants out of the system. So I believe that it is possible to grow plants that can be completely resistant to disease as long as they're supported with the right nutrition and with the right microbial biome. Microbiome, both of those are important. You can't have. If you just have really good mineral nutrition, but you don't have the proper microbiome, you're not going to be able to achieve strong disease resistance and vice versa. It really requires both. And for more information on the microbiome that is required for disease resistance, there's obviously a lot of really good information available today that wasn't available even a decade ago. But some new information that I'm very excited about and have been referring a lot of people to is Dr. James White's work on rhizophagy. So you can just do a Google search for James White and Rise of Fagy. You'll find some of his published papers and he has a number of YouTube clips. I hosted him on the podcast and we also put together a course with him on the Academy. The simple. And for this context, this information, the simple version of describing James White's work is to say that we have endophytes that are free living organisms throughout the plants and entire structure, including the vascular tissue, that have a symbiotic relationship with the plant and have the capacity to help suppress diseases on the leaf surface, in the rhizosphere, and also within the plant's vascular tissue. There's a lot more research and homework that needs to be done in this area, but his research is fascinating and will give you some very good insights. There are two different types of plant immunity that can be achieved in the field. The first type is what I refer to as passive immunity, where we simply. We know that every organism, every disease organism, every insect has a specific nutritional profile and a specific type of environment that it requires in order to thrive. And the concept of passive immunity, the idea that we simply remove that optimal environment, we make sure that the plant doesn't provide the nutrition and the right environment, the right context for that potential pathogen to express itself. We know that many of these organisms that we refer to as pathogens are quite ubiquitous in the environment. They're almost universally present. If we Take some Fasarium subspecies, for example, or some Phytophthora species. We know that they are present throughout the entire soil profile. In many agricultural soils, when you have a disease expressing itself, one field that has succumbed to the disease and a second that has not, there is often very little or even no difference in the quantity of the pathogenic organism in each gram of soil. The only difference is the other suppressive organisms that are either present or absent. And this is in the context of a soil environment. But the same concept also holds true for managing diseases within plant tissue, within plant structure, and on plant leaf surfaces as well. The second type of immunity is active immunity, where plants are actively producing immune compounds or resistance compounds from the induced systemic resistance and systemic acquired resistance pathway, which are sometimes referred to as the salicylic acid or jasmonic or jasminate pathway. As an example of the the type of thinking and some of the type of experiences that we've had in the past, I wanted to speak to our experience with bacterial canker on cherries. So bacterial canker, you have Pseudomonas syringiae, the that is not specific to the phloem, it's not specific to the xylem, but it is throughout the entire vascular structure and throughout the entire tree structure in the cytoplasm. As a bacterial infection, and it is considered to be essentially untreatable, you can cut out the damaged tissue and try to prevent it from spreading, but it does tend to spread fairly easily and quickly, and it is a significant challenge. So we began working with this particular producer, which is Mike Omeg. Some of you may have heard me speak of him in the past, in 2013 or 14, if I recall correctly, somewhere in that timeframe. And when we first began working with Mike, he had some blocks that had severe bacterial canker. And we started working on some of these blocks, and bacterial canker completely disappeared. The cankers that were present dried up. They were still there, but they did not spread, they didn't propagate. And eventually three years went by with no reoccurrence of bacterial canker. And if you've listened to the podcast, I interviewed Dr. Lynn Long from Oregon State University and also Mike Omeg, and both of them confirmed that bacterial canker had completely disappeared on these trees. And this is a photo of a field day that we hosted at Mike's farm. And he's holding a poster with the block that was so severely infected three years prior. That is, he's standing in front of these trees right now. So these are the trees before and after. Three years later, and when we first began working with this block, Mike's intention was to give us a one year opportunity to see if we could reverse them, and if not, he was going to doze them out and start over. So in that three year period, we were able to take yields from 2 tons up to 8 tons per acre and the trees completely recovered. If you want more information on this story, I'm not going to go in depth into what we did and the results that were observed, but you can. Mike Omeg has a video, our YouTube channel, where he has shared videos about what they were seeing both before and then also after. He has this one video that you'll be able to click on when you get the slide deck or on the video. And you can actually see firsthand what they observed and what they experienced in their orchard. So the question that we need to begin thinking about is, all right, if it's true that changes in nutrition and changes in the soil environment and the microbial environment can change a plant's susceptibility or resistance to disease, how can we measure that and how can we manage that? So I want to offer a different perspective that I've been learning about for the last couple of years on how to manage and measure these. So this is a perspective based on looking at a plant from a biophysics perspective rather than a biochemistry or a nutritional perspective. This is research that was originally, is built on research that was originally done by Louis Claude Vincent in France in the 1950s and 60s. And he developed this terminology of measuring plant bioelectronics where he was measuring EH, pH and electrical conductivity. Originally he was looking at water and human health and then that transferred to agriculture. And he developed this diagram where he had ph across the bottom of the chart and eh, electrical or not electrical conductivity, but redox along the left hand side of the chart. And he divided the chart into four quadrants and so you would have a quadrant that was alkaline and oxidized, a quadrant that was alkaline and reduced and acid and oxidized and acid reduced and so forth. And he identified different diseases as expressing in different quadrants, fungi versus viruses versus bacteria, etc. His research has been updated and brought up to 2020 and even beyond 2020 by Olivier Husson. Olivier Hassan has done incredible research on evaluating and monitoring plant health and identifying the zones where plants become susceptible.