You’ve taken all the proper steps — the right fertilizers, a perfect watering schedule — and yet the plants aren’t showing the results you’ve seen in the past.
Don’t fret. It’s not you; it’s your plants. Cannabis and hops are two commercially essential crops susceptible to many of the same pathogens, and Hop Latent Viroid is keeping cannabis growers awake at night — worried that HLVd will not only cut into profits but decimate entire crops.
Hop Latent Viroid (HLVd) is an infectious pathogen of cannabis plants. It first came to the cannabis industry’s notice in California in 2018. Now, the viroid has taken hold across the entire cannabis-growing community.
What is Hop Latent Viroid?
Hop Latent Viroid (HLVd) is a single-stranded, circular infectious RNA that ultimately depends on the metabolism of the host plant. As the name suggests, HLVd was first identified in the hop plant, but it can also infect cannabis — a relative of hops.
How does HLVd affect cannabis plants?
HLVd can cause physical symptoms in Cannabis sativa such as:
- Stunted growth
- Brittle stems
- Malformation of leaves
- Yellowing leaves
- Necrotic leaves
- Loss of smell
- Poor development and scattered trichomes
- Stunted bud growth
Research studies estimate that cannabis plants infected with HLVd had half the cannabinoid content of healthy plants, and overall yield was reduced by 30%.
How does HLVd spread?
HLVd can spread via pollination, but another leading cause is infected tools and equipment — so cultivators should always sterilize their equipment before starting work on a new plant. HLVd can also spread through cloning, when cuttings are taken from an infected mother. Because symptoms are not always evident in the vegetative stage, it can be hard to visually identify infected mother plants. This is especially true when infection occurs later in the plant’s development: stunted growth won’t be as apparent, but the infection will slowly evolve until the viroid takes over the whole plant.
How can we stop it?
That’s the million-dollar question. Here is what has been done so far:
- Testing: growers are investing in rapid testing that screens clones for HLVd before mixing them with other plants.
- Propagation techniques: using tissue cultures to grow cannabis from a single cell that can potentially be stripped of HLVd is promising.
- Sterilization: bleach and hypochlorous acid also seem to work. For large grows, water electrolysis machinery can spray plants twice a week. Small operators can buy relatively inexpensive jugs of these disinfection mixes and spray, soak, agitate, and brush plants individually to prevent spread.
HLVd detection
HLVd is a threat to the cannabis industry and could cause severe issues down the line if it isn’t dealt with properly. The viroid can remain latent or inactive within infected plants, making it nearly impossible to detect without molecular testing.
The viroid can remain latent — making it nearly impossible to detect without molecular testing.
To detect HLVd, a PCR test must be performed on a plant tissue sample after an RNA isolation procedure. The isolation offers increased sensitivity, which can be significant, as the presence of the viroid may be minimal in the infected plant. If you require HLVd testing, check out our MyFloraDNA HLVd Analysis. We’d love to help!
Catch HLVd before it takes the whole plant
Our RNA-isolation + RT-qPCR workflow detects HLVd even at minimal viroid loads — clones, mothers, and beyond.