Pcr testing has limited false positives. Based on the method of the test the only way you’d get a false positive is if the test itself was faulty or if there was a virus similar to hlvd (or covid if you’d like to compare it to that). False negatives can happen if the reaction doesn’t run long enough
I’ve gotten to the point I can identify it immediately.
Brittle stems being the most glaring issue.
@Medicine.grower id test a few in your stable just to see if you’ve got it in the line up. Odds are at this point that you don’t have it, but if you did everything would probably have it. So test a few and know for sure. It’s cheap as hell here in the states. $25 a test
An optimized seed coat disinfection protocol for cannabis seeds can be found here:
According to the optimization process, 4.6% sodium hypochlorite along with 0.008% hydrogen peroxide for 16.81 min would result in the best outcomes. The results of a validation experiment demonstrated that this protocol resulted in 0% contamination as predicted
HpLVd may be seed-borne (on the shell) of hops, but overall, HpLVd transmission by seed (at least for hops) is close to insignificant. I haven’t found research specific to the seed-borne transmission for cannabis seeds, but it can be transmitted through seed embryos. Considering HpLVd is transmittable mechanically (scissors, etc.), it’s not impossible that it can be transmitted on the seed coat depending on cultural practices.
Dark Heart’s plant pathology and research team recently announced the finding that the Hop Latent Viroid (HpLVd) seems to be transmissible through seed from infected stock. Leaf tissue from sprouted seedlings were tested and confirmed the presence of the Hop Latent Viroid.
“This important discovery furthers our understanding of how HpLVd is spread. Up until now, we had an idea that the viroid could be transmitted through seed but it had not yet been confirmed.” says Dr. Jeremy Warren, Director of Plant Health at Dark Heart.
While initial results suggest that transmission rate through seed appears low, further research is underway to determine what the actual rate is. Growers should remain vigilant and assume that unless their seeds are coming from a plant that is confirmed to be clean, their seeds may be infected with the viroid.
Similar results were found for hop cultivars Saaz and Premiant when the content of myrcene was increased by 29% together with monoterpene pinene isomers (about a 40% increase) for infected plants. On the contrary, all sesquiterpenes were reduced by 4.4% to 29% in cones of infected plants. From other compounds, terpene alcohols (linalool, geraniol, and methylgeranate) and epoxides were increased and ketones were decreased for infected plants [9].
So the problem with everything tasting like pinesol these days might not be CRC after all?
If any of my cultivars have it I wouldn’t be able to suspect they do by how they grow and root, my issue with the testing would be a so called false negatives, as in testing a plant that’s healthy but still infected.
I see lots of people testing but does negative really mean it’s negative?
Tumi genomics in co has proven to be incredibly accurate against other testing facilities. At least that’s what @The_Lone_Stiller and I have seen thus far. The team there is actually knowledgeable on what they’re doing and will happily discuss the process with you. Not just a receptionist giving misdirected Bologna
Much of the confusion comes from incorrect (sloppy) taxonomy and nomenclature of the pathogen we’re referring to: hop latent viroid. Found with published papers but mostly websites and even labs that offer pathogen testing. For example, the authors of Occurrence of Hop Latent Viroid Causing Disease in Cannabis sativa in California identified HLVd as a member of the non-existent Cocadviroid family.
HLV or HpLV = hop latent VIRUS (family Betaflexiviridae, genus Carlavirus)
HLVd or HpLVd = hop latent VIROID (family Pospiviroidae, genus Cocadviroid)
My assumption is the “d” indicates viroiD and “p” indicates hoP.
Moving forward, I will refer to hop latent viroid as HLVd. Because in Google Scholar, I found 19 results for HpLVd and 404 results for HLVd when searching for "HpLVd" + hop + viroid and "HLVd" + hop + viroid, respectively.
HLVd is the most common virus or viroid pathogen affecting Cannabis, and is the cause of dudding, as compared to these other viruses and viroids that infect Cannabis (drug cannabis and hemp):
Biggest tell tail sign I’ve seen is leaf twisting, throwing off 1 to 3 bladed leaves, cupping, horizontal growth, over all plant health not there, branches snapping to the touch and plants just dying without any reason (in flower specifically). Each cultivar should be tested with at least 5 pcr tests per plant, 10 if you can afford it, it’s super important to test plant material throughout the whole plant to get the most accurate result hard to get false negatives on 5 or more samples….this is a good podcast on hop latent bunch of Info from one of the owners of tumi worth a listen
Yeah, that’s a good episode; thanks for Dr. Saldi’s content.
The drawback to visually identifying HLVd is that it has likely spread throughout the facility unless strict cultivation controls are in place. I think if it were called Latent hop viroid, rather than hop latent viroid, more people would understand it’s a hidden danger, and once we notice it, it’s too late in most cases.
I don’t know about you guys/gals, but I have a hard time listening to that podcast. The dude Roach is the worst interviewer I have ever listened to. And most of the interviews are ads for Athena and Luxx disguised as a podcast. Although, to their credit, Luxx did hire one of the best possible scientists in Morgan Pattison. That guy is at the top of his field, and his academic background is outstanding. His Ph.D. advisor was the guy who created blue LEDs.
Definitely, Nothing beats testing, there are signs but can be too late by the time you even notice. If the podcast is a hard listen for anyone and still has questions tassa is also very accommodating at answering any questions if you email her, she’ll send you a bunch of research papers and will give you her opinion on the subject in question [tassa@tumigenomics.com]
Thanks for the tip! I will reach out to her. I need to run hundreds of samples soon, and I’m looking for the best lab and a lab that wants to set up recurring testing and may offer a discount. So far, I have heard they’re the best. I was planning to use LeafWorks.
With hundreds of tests, bringing testing in house makes a fair amount of sense. Doesn’t take much to set up pcr & gel electrophoresis, something like taq man might be even easier to implement .
