Hypochlorous acid and hops latent viroid

Hypochlorous acid and hops latent viroid

Hops latent viroid is a RNA virus that negatively impacts cannabis crops. As the name suggests, HLV originated in the hops plant, but was deemed "latent" because it does not come with distinguishable symptoms. It has since spread to cannabis, a distant cousin of hops, where unfortunately the effects are much more serious.

How does HLV affect crops?

In hops, HLV does not exhibit symptoms, but the reverse is true for cannabis plants. Infected plants suffer moderate to severe decreases in yield, trichome and leaf count, and cannabinoid content. Bud development suffers as well, with bud size and count lagging behind those of healthy plants. This phenomenon has been referred to as "dudding" throughout the industry, and it's become so serious growers are calling HLV "COVID-420". Some growers have reported up to 30% loss in yields per crop, and 40-50% reductions in THC concentration.

What is an RNA viroid?

A viroid is similar to a virus but is much smaller with a different genetic structure and can only replicate inside plant cells. Essentially, a viroid relies on RNA for its genetic material and can mutate much faster (and thus is harder to kill) than a DNA virus would be. For context, SARS COVID-19 is an RNA viroid.

How can HLV be prevented?

The hops latent viroid (HLV) is spread through mechanical contamination (dirty tools and equipment) and infected plant material (cuttings and clones). Once you've detected HLV in your crop, your best bet at eradicating it is tissue culture, which is expensive, time-consuming and not always effective. The role of hypochlorous acid (HOCl) in the greenhouse is to act as a highly effective and safe sanitizer. The overwhelming consensus is the best shot at preventing the spread of HLV is through appropriate greenhouse sanitation practices. Multiple research studies and experts have recommended using a 10% bleach solution to disinfect all surfaces and tools.  

Can hypochlorous acid prevent HLV?

To our knowledge, no scientific studies have been done to prove that any chemical can kill HLV once it has been established in a plant. And while there is substantial scientific evidence showing that HOCl is effective in killing other RNA viruses as a surface disinfectant, (eg; coronavirus, HIV, Hepatitis) it has not been proven to cure any of these viruses in humans. Therefore, we won't make any claims about HOCl's efficacy against eradicating HLV in plants.

HOCl has been shown to be at least 80 times more effective than bleach as a disinfectant. HOCl is the active sanitizing agent in bleach and is neutrally charged, which allows it to move past the cell wall of pathogens and kill them from the inside out. Bleach is negatively charged and can only repel pathogens, which is less effective. HOCl is also non-toxic and less caustic to equipment than bleach.

To prevent the spread of HLV, HOCl should be used to sanitize propagating equipment, cutting knives, and work benches between jobs. For sanitizing tools, we recommend using 200 ppm for soaking or 500 ppm if used as a dip. HOCl can be applied directly to skin and does not need to be rinsed off.


Hull, R. (2014, January 1). Chapter 5 - Agents Resembling or Altering Virus Diseases (R. Hull, Ed.). ScienceDirect; Academic Press. https://www.sciencedirect.com/science/article/pii/B9780123848710000054

Puchta, H., Ramm, K., & Sänger, H. L. (1988). The molecular structure of hop latent viroid (HLV), a new viroid occurring worldwide in hops. Nucleic Acids Research, 16(10), 4197–4216. https://doi.org/10.1093/nar/16.10.4197

Poltronieri, P., Sun, B., & Mallardo, M. (2015). RNA Viruses: RNA Roles in Pathogenesis, Coreplication and Viral Load. Current Genomics, 16(5), 327–335. https://doi.org/10.2174/1389202916666150707160613

Wilson, T. (2021, April 1). The Hop Latent Viroid’s warning shot to the Canadian cannabis industry. StratCann. https://stratcann.com/2021/04/01/the-hop-latent-viroids-warning-shot-to-the-canadian-cannabis-industry/

Ling, K.-S. (2017, January 1). Chapter 41 - Decontamination Measures to Prevent Mechanical Transmission of Viroids (A. Hadidi, R. Flores, J. W. Randles, & P. Palukaitis, Eds.). ScienceDirect; Academic Press. https://www.sciencedirect.com/science/article/pii/B9780128014981000413

Hop Latent Viroid in Cannabis. (n.d.). Medicinal Genomics. Retrieved July 7, 2022, from https://www.medicinalgenomics.com/applications/hop-latent-viroid-in-cannabis/

Photo by CRYSTALWEED cannabis on Unsplash

Leave a comment

Please note, comments must be approved before they are published