The $4 Million Problem: Hop Latent Viroid's Impact on Cannabis Cultivation ft. Dr. Tassa Saldi

Unveiling the $4 Million Problem: Hop Latent Viroid's Impact on Cannabis Cultivation ft. Dr. Tassa Saldi

Bryan Fields: What's up guys, welcome back to another episode of The Dime. I'm Bryan Fields, with me as always is Kellan, and this week we've got a very special guest, Dr. Tassa Saldi, Chief Scientific Officer at Tumi Genomics. Dr. Saldi, thanks for taking the time. How are you doing today? Dr. Tassa Saldi: I'm doing great, thank you so much for the opportunity to speak with you guys. We're excited to talk about a bunch of topics. Kellan: How are you doing? I'm doing really well, really excited to talk to Tassa, really excited to talk about science, and I'm even more grateful that it's another West Coaster we have on the pod today. How are you doing, Bryan? Bryan Fields: Yes, I'm excited. Kellan, you're right, we have to clarify — if you had to put yourself on the record, Dr. Saldi, where would you put yourself, East Coast or West Coast? Dr. Tassa Saldi: Oh, sorry, was that an East Coast West Coast battle? I didn't want to give you too much setup. Can I just go agnostic? Can I not vote? Bryan Fields: I love it. Let the record reflect, Kellan, you almost had one, but we're going to put this one TBD, for sure. Kellan: So I think before we dive in, it'd be great to give a little background about yourself and Tumi Genomics as a whole. Dr. Tassa Saldi: Yes, absolutely. So as you mentioned, I'm the Chief Science Officer at Tumi Genomics. I was actually born and raised in Colorado, so I'm a country girl I guess, and I did all of my education here in Colorado. All of my education is in biology, specifically molecular biology, and even more specifically in what we call RNA biology — that's a molecule kind of similar to DNA that carries information, and that's also the molecule that carries information for hop latent viroid. So it's very on point for this specific disease. In my graduate work and postdoc I studied RNA and specifically how the three-dimensional shape of RNA can control actions in the cell, and that's oddly enough also exactly how hop latent viroid enacts part of its biology inside a plant cell. So even though it's a devastating and horrible disease for the cannabis industry, it's also scientifically incredibly fascinating, and I really enjoy working on it because I think it's really, really interesting. Kellan: How long have you been working with viruses? Dr. Tassa Saldi: I've been working with structured RNA a long time — that's where I started at the beginning of graduate school. We moved specifically into viruses right around COVID, so 2019, and we actually started running the COVID surveillance lab at CU Boulder. We did that for about a year and a half, and that's where our company really cut our teeth on in vitro assays, understanding viral biology, high-throughput diagnostics, and how to validate tests and understand if they're working or not. So it's been about four years with virus/viroid biology. Bryan Fields: So hop latent viroid — I'd love for you to give our listeners a high-level overview of what it is in layman's terms, and then from an economic impact standpoint, how prevalent is this and how much is it affecting cannabis today? Dr. Tassa Saldi: Yes, absolutely. Hop latent viroid, and all viroids, are really weird, unique organisms, if we can even call them that. Most organisms on the planet have two components: information inside them in the form of DNA or RNA that tells the organism how to be whatever it is, and an outside coat and more complex biology that protects that information and helps interpret it. Viroids are unique in that they're just the information, and that's it — a free-floating piece of genetic information and nothing else. It's much more similar to leaving your DNA behind at a crime scene than it is to a bacteria or a living thing. Because of that, it enacts everything it does by hijacking the biology of the plant and forcing the plant to replicate the viroid instead of doing what it's supposed to be doing. That process can be incredibly devastating to the plant — over time you can end up with stunting and funky growth, and probably the worst and most economically impactful symptom is that it really tanks the quality of the flower. You see dramatically reduced THC content, reduced yield, reduced terpenes — everything just kind of duds out, which is why they call it the dudding disease. Unfortunately, because cannabis was in legal limbo for so long and everybody was growing underground and trading clones underground, this disease silently passed into the cannabis industry, and because of the culture and legal landscape, it spread throughout the entire industry without anybody being aware it was happening. When it was finally discovered in cannabis around 2018-2019, it had already spread pretty much worldwide. At this point we've detected hop latent viroid in cannabis on pretty much every continent — the United States, Canada, Africa, Asia, everywhere. It's in about 80% of the facilities that test with us, so if you don't have an issue with hop latent viroid, you're the unique one. Because it has the biggest impact on the yield of flower, and that's where all the value comes in for cannabis, it's causing a huge economic problem. The estimate is like a $4 billion-a-year problem, and it can reduce your revenue by about 30%, which is a lot when everybody's already on the edge in the cannabis industry right now. Bryan Fields: It seems overwhelming, not a unique case or a one-off — pretty universally seen around the industry. Is it something you can see optically when walking a facility, or do you have to test for it? Dr. Tassa Saldi: It's both. There are some symptoms, and in certain cultivars they're extremely prominent — stunting, branches coming out more horizontally, funny-shaped leaves, sometimes chlorotic or miscolored leaves. Unfortunately, in some cultivars the symptoms are incredibly subtle or nonexistent — you see nothing during veg, and then they flower and it's completely dudded out with no warning. So the only way to really mitigate it and keep yourself safe is to get into some type of regular testing schedule. Bryan Fields: Does it still affect the plant if it's dormant, or does "latent" mean something else? Dr. Tassa Saldi: "Latent" was an unfortunate name, because it does mean dormant in viroid biology, but what they meant to say was asymptomatic. It's always going to be replicating for the most part in the plant, but there are some cultivars where it replicates very slowly or spreads very slowly, or that particular strain just doesn't care. So you can have cultivars with a ton of viroid and no symptoms and no yield loss — it's very specific to the cultivar. Bryan Fields: So it sounds critical to be proactive in testing rather than reactive, because if you assume you don't have it and you're one of the 80% that do, you could end up with a dud yield that sabotages your cycle economically. Dr. Tassa Saldi: Yes, absolutely. It generally comes in on new genetics, and if you aren't proactively testing and looking for it, it will spread silently throughout the entire garden. The issue isn't just one harvest lost — it's that all of your genetics, some incredibly valuable, are now infected with a disease that doesn't have a simple cure. The best solution is often to throw everything away, but that's a huge economic hit, so it's better to protect yourself from the beginning than to fight that battle after everything's infected. Kellan: Are there other agricultural industries that have been affected by this? I was going to say hops, but has there been solutions generated there that cannabis can look to? Dr. Tassa Saldi: Yes, absolutely. For hop latent viroid specifically, the only other crops besides cannabis with natural infections — meaning not inoculated in a lab — are hops, like you mentioned, that's where the name comes from, and stinging nettle actually, which most people aren't cultivating massive amounts of. One of the issues, probably why this is so prevalent, is that the majority of cultivars in hops are asymptomatic, which is why they called it hop latent viroid in the first place. So they haven't done a lot of mitigation in hops because it doesn't affect that crop nearly as much. The best mitigation effort widely deployed in other systems with similar viroids is testing and clean stock — that worked really well for potato spindle tuber viroid, and it's a model we can adapt to cannabis to help people get through it or avoid it. Kellan: One of the benefits is Tumi has a solution that can help with this problem. I'd love for you to get into that solution and then we can dive into the specifics of building it. Dr. Tassa Saldi: Yes, absolutely. On a bigger scale, it's the proactive versus reactive approach I mentioned, and the proactive approach involves four major steps. We created a dorky acronym to help people understand it, called STOP — mostly common sense things that help limit entry and spread. It stands for Sterilization, a clean Testing program, Organizing your facility after you understand what you're up against, and Protecting it from entry of these pathogens into your plants. Bryan Fields: So how does the process work? Say I'm a cultivator, I may or may not have a problem, maybe I'm being proactive — I call you and say, what do I need to know in order to prepare myself? Dr. Tassa Saldi: The first and most important thing is realizing that to limit pathogen entry and spread you need a system-based approach — instead of just testing plants or not taking in new genetics, you look at your entire process and identify critical control points or weaknesses. This concept goes beyond hop latent viroid — there's fusarium, pythium, other things that could ruin your day. We help people go through their entire cultivation process, identify those critical control points, and help them make small changes that fit into their workflow but drastically reduce their probability of infection or help them limit spread. Part of this is coming up with an intelligent surveillance or testing program. At Tumi Genomics we help people build these programs — it used to involve TaqMan PCR, which we offer as an in-lab service, testing plants at specific time points, and organizing something called clean stock, which separates your genetics from the rest of the cultivation process to keep them safe. We've also recently released an on-site testing platform integrated into the testing program, so growers can capitalize on the strengths of both in-lab PCR and the convenience of on-site testing. It depends on the facility, but basically we build a plan that protects people and gives them the information they need to understand these pathogens and how to keep themselves safe. Bryan Fields: So essentially you're compartmentalizing every step of the cultivation process and putting gating features in between to ensure something contaminated doesn't pass to the next step. Dr. Tassa Saldi: Yes, absolutely. Most of these things are incredibly simple in practice — if you reuse your plastic pots, you need to sterilize them first, because that's a step a lot of people skip and it spreads pythium through the facility. When you're dipping clones, you don't want to dip all of them in the same clonal gel, because that becomes an inoculum for every plant dipped in there. Testing at critical points — if you identify a positive plant and pull it out, you're protecting the maximum number of plants downstream and the maximum amount of investment. Really what we're talking about here is risk aversion. Bryan Fields: How valuable has it been for people who've implemented the on-site testing system? It sounds like it saves a ton of time. Dr. Tassa Saldi: Yes, we just deployed the system in February, so we don't have a ton of in-facility data yet, but a lot of people, especially right before cutting clones, want to test their mother plants to make sure nothing is sick, so they're not cutting an entire room full of fusarium or hop latent viroid. There's a huge waiting time for lab results, sometimes an entire week. Being able to do that in one day saves a massive amount of labor and improves efficiency — in some calculations, if you eliminate that waiting, you could even add another harvest into the cycle. There's a lot of money to be saved by improving that efficiency. Kellan: Congratulations, because understanding the development cycle — optimization, validation, beta testing, re-optimization — is not a small feat. I'd love for you to explain why something like that takes so long. Dr. Tassa Saldi: I knew development was going to take a long time, but it took even longer than I thought. When developing this type of technology, there are two critical things: one, obviously the technology has to work, and two, you have to prove that not only can a scientist do it in a lab, but a regular person could do it too. Oddly enough, it's so much easier to design a difficult, complex test for a scientist than to design something really easy. Those were our two biggest challenges. It was incredibly important to us not just to make a good test, but a test that pushed the boundaries of what's possible, because I feel the cannabis industry has been underserved scientifically and the bar hasn't been placed very high. We did more than a year of optimization improving the limit of detection, accuracy, changing buffers and amounts, and then we released it to beta testers, which brought a whole other level of issues — ways people could make mistakes we'd never considered. That took another nine months of taking feedback and iterating. It was a long haul and a big investment, but important, because I want it to be great, easy to use, and useful to growers. Kellan: When you were optimizing the technology for the everyday operator, how did you handle conversations where operators wanted to get into the weeds on PCR and high-level details your team spent careers developing? Dr. Tassa Saldi: That's a great question. What I find, in general with teaching biology, is that the concepts themselves aren't that challenging — it's the vocabulary that people struggle with. Once you start throwing out words like isothermal amplification and hybridization, people are like, whoa. But if you replace those words with concepts people understand in their day-to-day lives — like, your DNA is like a book in a library, each sentence is analogous to an RNA molecule — it's easier for them to grasp. Some drawings help too. I actually really like teaching, so I enjoy those conversations. Bryan Fields: It's a fine balance to have this incredibly complex science and simplify it for an everyday person, while still ensuring the test is used correctly so results are valid. How do you balance that? Dr. Tassa Saldi: A huge part of it is removing the complexity — taking steps that would normally require scientific equipment like a pipette and finding alternatives people are comfortable using, like a squeeze bulb, like a turkey baster, a movement a regular person already does. We find instruments that are easy to use and don't require understanding what a microliter is. We also provide a lot of support — every on-site testing customer gets a personalized onboarding, either a video call or in person, showing them how to use it. A lot of it is trial and error; we had six different facilities beta test, and we got all sorts of questions and mistakes, which we used to preemptively give advice and help people set things up correctly. Bryan Fields: Let's go through some of those beta tests. What were the reactions when you approached these cultivators? Dr. Tassa Saldi: Honestly, the majority of people we approached were excited about it. A couple people started and then got too busy, or lost an employee and there wasn't anybody to run it, but most people we talked to were really excited. That's one of my favorite things about the cannabis industry — customers will call and ask a question, and I'll say, well, nobody knows, so how would you like to do an experiment with us and find out the answer? And usually they're like, yeah — which is so cool, because that's not true in every industry. Bryan Fields: Were there times during beta testing where there was a false positive, a panic, and they called you? Dr. Tassa Saldi: The way we did it was similar to how accuracy is checked with tests going through the FDA. Everybody who did a beta test got the Tumi Glow, our on-site testing reaction, and also PCR tubes that matched exactly, so for every plant tested they tested both Tumi Glow and in-lab PCR. We told them: whatever Tumi Glow says, don't panic, don't do anything with it — if you got a positive you could set it aside, but wait for the PCR result before acting. That way we were constantly monitoring accuracy and could make corrections. The beta testers were awesome, because that's a lot of extra work, collecting samples for two tests on the same plant. Kellan: In looking for beta testers, were you seeking out cultivators with known pain points, or approaching people saying, you may have this, here's a tool that could benefit you? Dr. Tassa Saldi: We were in a cool position because we'd been providing in-lab services to a lot of people for a long time, so we already knew which facilities might have issues and be excited to try something like this. We could select people across all different sizes of grows and skill levels — one beta tester with a master's degree, another more of a regular person — which was incredibly useful for getting a feel across the board of how it would be handled. Kellan: And you'd established that trust with these partners via prior third-party testing? Dr. Tassa Saldi: Yes, they were all previous customers of ours, so they already knew us. They were very understanding when things worked great in the lab and then things went wrong in a cultivation facility that we hadn't anticipated — we'd say, okay, we'll be out there tomorrow with a different type of tube or capillary. They were really cool about trying new things and helping us out. Bryan Fields: For cultivators who don't use this type of testing, is it a cash challenge, or are they more reactive than proactive? Dr. Tassa Saldi: It's all over the map. Cost is definitely an issue — the cannabis industry is in a precarious position, and a lot of people don't have extra cash for testing. Some of it is a planning issue — in general agriculture, especially the nursery industry, preventative testing is just a line item in the budget, it's part of the process. But because cannabis is kind of a wild west with everybody doing their own thing, it doesn't always make it into the budget, so sometimes it's a "we've never done this before, why would we do it now" mentality. The best way is to realize during setup that you need pathogen testing as part of your budget for a new facility, so it just becomes part of the process, but a lot of people didn't start that way, so they're dialing back into it. Bryan Fields: If a grower does have the virus on their plants, is there any possibility for mitigation besides throwing everything away? Dr. Tassa Saldi: Tissue culture is an option — we don't do tissue culture at our facility, but it works, not 100%, and better with some cultivars than others; it can be a long process. There are other possibilities for treatments involving targeting the specific letters in the genetic information of the viroid — there's evidence in the literature that this works, and we'd love the opportunity to develop that; it's a longer-term plan of ours. There's also a possibility for identifying what makes some cultivars resistant and engineering that into your favorite cultivar so it doesn't catch it easily. Bryan Fields: What about something like a vaccine for plants? Dr. Tassa Saldi: Plants don't have an adaptive immune system like mammals with antibodies, but they do something called RNA interference, which follows a similar concept. The idea would be to trigger that portion of the plant's immune system ahead of time so it's primed when exposed to the viroid, already having the tools to fight it off, or giving it those tools right at infection so it can fight it off. Similar idea to a vaccine, just different words. Kellan: Are there other pathogens or viruses you foresee becoming prevalent in cannabis, similar to how hop latent viroid became widespread around 2018? Dr. Tassa Saldi: Right now, the two other pathogens that I think don't get enough press but are incredibly important are fusarium and pythium — root molds/fungus, especially for indoor growers. I call those three the three horsemen of the cannabis apocalypse. As for other pathogens affecting outdoor grows more specifically: beet curly top virus, lettuce chlorosis virus, tobacco streak virus, alfalfa mosaic virus — all things to think about if you have an outdoor facility; much less common indoor. Hop latent viroid also isn't the only viroid that infects hops, and definitely not the most damaging — there are others like hop stunt viroid, apple fruit crinkle, citrus bark cracking viroid, all of which have the potential to replicate using cannabis biology. Nobody's identified them in cannabis yet, but it's possible they'll jump in too, which is why it's so important to have a proactive plan in place — not just for what's happening now, but for what's going to happen. Bryan Fields: Do you see viruses affecting indoor grows more than outdoor, or is it about the same? Dr. Tassa Saldi: For hop latent viroid, it's pretty similar, though outdoor concern might be slightly lower since you can plant more plants more cheaply. As for other viruses, a large number are transferred by insects and some are geography-specific — like beet curly top, transferred by the beet leafhopper, much more common in the Western United States. So if you don't have that insect in your facility, or you're in Michigan, it's going to be incredibly rare. For those, outdoor is way more common than indoor. Bryan Fields: Is there a certain percentage of budget growers should allocate toward testing? Dr. Tassa Saldi: I've heard from Travis, who established Due Diligence Horticulture Consulting, that you'd want to budget about 2% for IPM, which includes testing. The way I encourage growers to think about it: think about the value of a mother plant — not just that plant, but everything that will come from it, how many clones you cut, how many pounds of flower that ends up making. If it's $10,000, would you pay $25 to insure that $10,000? When you think about it like that, it's obvious why you would, because there's so much money on the line that you could lose, and you can basically buy insurance for it ahead of time. Bryan Fields: And if an organization wants to implement testing, they don't have to go from zero to a full on-site suite right away — they can start small and build a plan with your help? Dr. Tassa Saldi: Yes, absolutely, that's actually how we recommend people do it. We usually have them start with a baseline — testing a small percentage of their plants — and we determine the pathogen pressure in the facility, then work with their budget to implement the smartest program we can. That doesn't always involve a ton of testing; we don't want people testing every single plant every week, that's insane. We want the right amount of testing for their situation. Kellan: If there was one message you could send to cultivators about this overall approach, what would it be? Dr. Tassa Saldi: The most important thing to remember is that although hop latent viroid is expensive and scary, and there's a lot of fear, there's a way to mitigate it, and there's no reason to be afraid. It's about gathering information, creating a logical system to stop the spread or entry, and instigating that system by following the programs. Instead of being afraid, you have a plan and can protect yourself, and part of that is being proactive instead of reactive. Bryan Fields: Say I'm a grower, I have an indoor crop coming down, I test it, it's got hop latent viroid, but I need the cash to keep running my business. Are there ways to isolate that flower room, even knowing yield will be lower, to still generate some revenue while transitioning? Dr. Tassa Saldi: Yes, in fact that's the most common situation — most people can't just shut down for six months. What we do when designing these programs is help them create their clean stock in the background of their normal cultivation process, still using the infected plants since those are the plants they have and growing, but sorting through mother plants to look for clean stock and building up that genetic library in the background. Once you've found clean stock for a certain cultivar, you start integrating it into your process. It's slow, sometimes up to six months, but you're not losing efficiency — you're just doing something extra in the background. Kellan: From a consumer standpoint, is it still safe to consume products that have hop latent viroid, and can consumers tell if a plant has it? Dr. Tassa Saldi: Hop latent viroid and viroids in general do not infect mammals — the biology is very specific to land plants, so it's not dangerous to ingest, just like genetic material in any other food. You actually can sometimes tell — I've gotten a pre-roll before and thought, oh, this was infected, mostly because it doesn't do anything, the THC content is so low, or the bud is super fluffy and underwhelming — that's a telltale sign of hop latent viroid. Bryan Fields: If you could put anything on a billboard, metaphorically speaking, to reach billions of people, what's the first thing that comes to mind? Dr. Tassa Saldi: Never give up — that's what I had to keep telling myself throughout this whole startup journey. Bryan Fields: What question do you wish more people asked you? Dr. Tassa Saldi: I'd love to be asked, ahead of time, how do I organize my facility to address pathogens proactively — what do I do before I've even opened the building — and explain to me the biology of hop latent viroid, what do I need to know to prevent or mitigate it. Kellan: Dream smoking session, three people dead or alive? Dr. Tassa Saldi: My grandmother, that one will be fun. Albert Einstein. And my first scientific mentor, Tom Blumenthal — I think it'd be fun to share a joint with him. Bryan Fields: What is the most expensive lesson you've ever learned? Dr. Tassa Saldi: Plan ahead — or as some of my professors used to put it, two weeks in the library can save you two years at the bench. Planning before you jump in and try to do something. Bryan Fields: Prediction time, Dr. Saldi — in the next five years, how do you anticipate advancements in cannabis genomics will revolutionize cultivar development and crop protection strategies? Dr. Tassa Saldi: I'm hoping that in the next five years, at least from a pathogen standpoint, we understand what genes contribute to resistance and can introduce those genes into cultivars to help them be immune to a lot of these problems. Also, just understanding the cannabis genome in general — I hope that leads to preservation of a variety of different cultivars, because I have a nagging fear that everyone's so fixated on THC that we're losing all these exciting chemicals with medicinal applications. That's my hopeful wish for the next five years, that that becomes a priority. Kellan: I think there's going to be hybridization within the cannabis plant merging traits from fiber hemp into flower cannabis — cultivars that grow 16 feet high, can be used for textiles and building materials, but also bud, creating flowers with medicinal compounds. That'll let organizations diversify revenue from a single crop. Bryan Fields: I think it's an overall fundamental switch from being reactive to proactive. Maybe now the balance is 50/50, but over time, as more people get hit with pathogens causing massive disruption, the industry's overall message will shift toward being more proactive, which I think will do a lot of good for business too. Bryan Fields: Dr. Tassa, for those who have hop latent viroid and are interested in testing, where can they find you? Dr. Tassa Saldi: We have a website at tumigenomics.com. We're on LinkedIn, Instagram — you can shoot us an email, send a message on Instagram or LinkedIn, contact us through the website, we have a chat function there. My email is tassa@tumigenomics.com, you're welcome to shoot me a direct email. I'm happy to help set up a testing program, or just answer questions about hop latent viroid and sterilization — I don't mind that at all. Feel free to contact us through any of those forums and we can help you out. Bryan Fields: Thanks for taking the time, this was a lot of fun. Dr. Tassa Saldi: Yes, absolutely, thank you so much for inviting me, I had a great time.