Understanding and Preventing HpLVd in cannabis

As the legal cannabis industry continues to grow, cultivators face various challenges in maintaining healthy crops. A significant threat that has emerged in recent years is the Hop Latent Viroid (HpLVd), a tiny but destructive pathogen that can devastate cannabis plants. First reported in California in 2019, HpLVd has been reported to be present in most countries where cannabis is legal.

What is HpLVd?

HpLVd is a viroid, a type of infectious agent even smaller than a virus.

Viroids are single-stranded, circular RNA molecules that don't encode proteins but can replicate in host cells, causing disease.

How HpLVd Affects Cannabis:

In cannabis, HpLVd can lead to a condition known as "dudding," characterized by stunted growth, reduced yields, and lower cannabinoid content.

• Stunted growth and brittle stems
• Reduced flower size and density
• Lower THC and CBD content
• Decreased overall yield
• Increased susceptibility to other pathogens

Transmission of HpLVd:

HpLVd can spread through various means:

1. Mechanical transmission (contaminated tools, hands, or clothing)
2. Grafting of infected plant material
3. Seeds from an infected parent

Preventing HpLVd in Your Cannabis Crop:

1. Start Clean: Use certified disease-free clones or seeds from reputable sources.
2. Implement Strict Sanitation Protocols:
   • Regularly disinfect tools, work surfaces, and grow areas
   • Use disposable gloves and change them between plants
   • Limit unnecessary touching of plants
3. Quarantine New Plants: Isolate new additions to your grow for at least 30 days and monitor for symptoms.
4. Regular Testing: Implement a testing regimen to catch infections early. PCR tests can detect HpLVd before symptoms appear.
5. Train Staff: Educate your team about HpLVd, its symptoms, and prevention methods.
6. Optimize Growing Conditions: Healthy plants are more resistant to infection. Maintain optimal temperature, humidity, and nutrition.
7. Consider Tissue Culture: For large-scale operations, tissue culture can help maintain clean mother plants.
8. Remove Infected Plants: If HpLVd is detected, remove and destroy affected plants immediately to prevent spread.

Managing an HpLVd Outbreak:

If you suspect or confirm an HpLVd infection:

1. Isolate affected areas of your grow
2. Increase testing frequency
3. Enhance sanitation measures
4. Consider discarding all potentially infected plants and starting fresh with clean stock
5. Use bleach in a 10% solution to disinfect pots, tools, work surfaces, benches, etc.

While HpLVd presents a significant challenge to cannabis cultivators, understanding the pathogen and implementing rigorous prevention measures can greatly reduce the risk of infection. By staying vigilant and maintaining strict biosecurity protocols, growers can protect their crops and ensure the production of high-quality cannabis.

Remember, prevention is always easier and more cost-effective than dealing with an outbreak. Stay informed, be proactive, and prioritize the health of your cannabis plants to safeguard against HpLVd and other potential threats.

Further reading: Hop Latent Viroid: A Hidden Threat to the Cannabis Industry