Is Phytovirus the COVID-19 of cannabis?

“In 2019, every single garden that was tested for pathogens, mold, and other standard tests came back positive for this virus.”

New and improved viruses mutate and spring up all the time. Every year we’re talking about a different strain of the flu, a new virus altogether, or a mutation of a virus, such as coronavirus (COVID-19), which has been making waves all over the world. The plant kingdom is no different than ours in the sense that these bugs find new ways to do what they do all the time. Viruses like the coronavirus invade healthy cells in order to reproduce and face a lot of challenges as immune systems evolve and adapt to destroy them. This year’s latest viral scare is targeting cannabis plants and hops, and it’s starting to affect them drastically. Phytovirus could potentially lead to serious repercussions, including crop loss or the total eradication of our favorite strains. Here’s everything you need to know about Phytovirus, how you can catch it early, and how to kill it. 

What is Phytovirus? 

Phytovirus, also known as the Hop Latent Viroid (HpLVd), is an infectious pathogen known as a “viroid” and is smaller than a standard virus. It can cause a serious disease in cannabis plants known as “dudding” or “dudding disease”. If you’ve heard of the putative cannabis infectious agent (PCIA), you’ve heard of phytovirus since it actually causes PCIA.

If the virus is left untreated, HpLVd can decimate a crop’s potency levels and yield. Not just cannabis, either. This virus can affect hops, catnip, nettles, and many different trees and shrubs. Most cannabis gardens (both personal and commercial) have an infection rate of about 25-50% with HpLVd, causing an estimated 44 million dollars in losses every year. 


The infections usually occur when infected plants or clones are introduced to a healthy garden, where it spreads aggressively to other plants. Some get it through mechanical transmission with dirty pruning shears transferred from plant to plant. The virus can also be spread through the seeds of the infected plant. 

However, the kicker is that many plants are asymptomatic. Some plants infected with the virus show symptoms while many others do not. Some plants carry the virus where it remains dormant for extended periods of time before starting to show signs that they have the virus. This is why phytovirus is so difficult to detect and eradicate. Asymptomatic plants may appear healthy and spread the pathogen to other plants in the garden. 

In 2019, every single garden that was tested for pathogens, mold, and other standard tests came back positive for this virus. Plants that show symptoms for the virus usually look droopy, produce abnormal branches and smaller flowers, yield much less than usual, and begin producing trichomes later than usual. You should also look out for slow growth, reduced size, discoloration and deformation of young leaves, abnormal nutrient absorption, reduction of flower size and weight, decrease in resin production, aromatic intensity, flavor, and potency.

Luckily, there are things that can be done to prevent the virus from spreading and ways to eradicate it from your garden. 

How can Phytovirus be prevented? 

The first step in preventing phytovirus from spreading is testing to see whether or not your garden actually has it. While many commercial growers are required to get testing done by law, personal gardens can also be tested for a great price here at CanMed Labs. 


To prevent phytovirus from killing your garden, you should first get your plants tested to detect the presence of the viroid. Even healthy plants may be infected. Infected plants should be removed from the garden and destroyed. Plants that may have been infected (because of proximity or cross-contamination) should be quarantined and tested too. 


However, hygiene is also crucial in a cannabis grow. Take great care to: 

  • Keep your trimming and pruning tools clean. Clean them with rubbing alcohol before using them on another plant. 
  • If you handle an infected plant, don’t touch a healthy one without washing your hands. 
  • Make sure your plants have enough space and don’t come into contact with each other.
  • Kill all aphids and nematodes since they carry this phytovirus. 
  • Clean and disinfect your growing space and all of your equipment after every run.
  • Limit clone exchanges and always quarantine new plants so you can get them tested before putting them in your garden. 

Can phytovirus be killed?

Controlling this virus and testing for it regularly is vital to the success of the cannabis industry since there is currently no way to effectively eradicate it. It doesn’t respond to biological or chemical treatments, so infected plants must be immediately removed from your garden and destroyed. 

For many, this just isn’t possible. Many cultivators have extensive, proprietary strains that cannot be destroyed without causing some serious financial damage. If that’s the case, there is one thing you can do to save the plant. However, it’s something you’ll have to outsource to a lab.

If you have a unique, exotic, or proprietary strain that tests positive for the virus that you don’t want to dispose of, you must eradicate the virus via an in-vitro propagation tissue culture process. This proprietary treatment can eliminate the viroid and leave you with a healthy strain that doesn’t carry or transmit the disease. 

Lab Testing Is the Industry’s Best Chance.

Catching and eradicating the Hop Latent Viroid is crucial for the longevity of the cannabis industry and the health of the species. To do that, it’s vital to get your garden tested. Can Med Labs specializes in helping the cannabis industry with affordable lab testing and screening services with a turnaround on results being 48 hours or less. We offer HpLVd screenings as well as tests for potency, mold, pesticides, heavy metals, moisture, microbials, mycotoxins, residual solvents, terpenes, cannabinoids, and more. 

We can even help you save your favorite strains, should your test come back positive. 

Contact us today learn more on how Canmed can assist with Genetic based testing for HpLVd in symptomatic and asymptomatic plants.