{"id":178976,"date":"2024-02-05T11:56:31","date_gmt":"2024-02-05T09:56:31","guid":{"rendered":"https:\/\/atami.com\/?p=178976"},"modified":"2026-04-22T11:40:44","modified_gmt":"2026-04-22T09:40:44","slug":"battling-the-hop-latent-viroid-hlvd-a-new-threat-for-hemp-crops","status":"publish","type":"post","link":"https:\/\/atami.com\/usa\/blog\/cultivation\/battling-the-hop-latent-viroid-hlvd-a-new-threat-for-hemp-crops","title":{"rendered":"Battling the Hop Latent Viroid (HLVd): a New Threat for Hemp Crops."},"content":{"rendered":"\t\t
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Imagine a nightmare scenario for any cultivator: poor yields, small and scentless flowers, deformed and yellowing leaves, stunted and fragile plants. Unfortunately, this is not a fiction but a reality that has haunted many North American licensed producers in recent years. The culprit behind this agricultural horror story? The hop latent viroid, also known as HLVd or HpLVd which causes dudding’s disease in hemp. Join us as we explore this new threat to hemp cultivation and learn how to safeguard your crop.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t

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In the picture on the left a control hop plant and on the right a hop plant infected with HLVd. An abnormal growth of the hop leaves is shown. Similar symptoms are also detected in infected hemp plants. Image source: Adkar-Purushothama, C.R.; Sano, T.; Perreault, J.-P. Hop Latent Viroid: A Hidden Threat to the Cannabis Industry. Viruses 2023, 15, 681. https:\/\/doi.org\/10.3390\/v15030681<\/figcaption>\n\t\t\t\t\t\t\t\t\t\t<\/figure>\n\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t
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Understanding the Hop Latent Viroid (HLVd) and Its Implications:<\/h2>\n

Viroids, the simplest known infectious agents, exclusively target plants. Structurally composed of a single molecule\u2014RNA, a type of genetic material\u2014they lack proteins and aren\u2019t considered living entities. With around 300 viroids that specifically infect plants, their selectivity is remarkable. Each type of viroid infects exclusively a certain type of plant, or plants, within the same genus.
One such viroid is the hop latent viroid (HLVd), originally affecting hop plants worldwide. However, it has now become a significant concern for hemp cultivators. Due to the close botanical relationship between hop and hemp, the viroid’s resources for infecting one type of plant are useful for infecting the other because of their similarity.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t

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The picture shows a healthy hop plant in its flowering phase. Certain similarities can be observed between the morphology of hemp plants and hop plants due to their phylogenetic closeness. <\/figcaption>\n\t\t\t\t\t\t\t\t\t\t<\/figure>\n\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t
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Sadly, infection rates in cannabis plants have skyrocketed in the USA and Canada. Especially in the state of California, where a 2021 survey made with 200,000 tissue tests found that around 90% of hemp crops have already suffered from this infestation. This issue transcends borders, spreading rapidly to regions like South America and Europe, fueled by globalisation.<\/p>\n

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Impact on Hemp:<\/h2>\n

While most HLVd-infected plants remain asymptomatic, research on hop plants has shown a decrease in both alpha-bitter acids and terpene content in hop cones, affecting their economic value.
Unfortunately, the same is true for hemp plants. Plants affected by HLVd often produce lower yields and the harvest is of poorer quality. This is due to a reduction of up to 50% in the production of cannabinoids and terpenes.<\/p>\n

With smaller and less compact flowers, poor aromas and less trichome production, the economic loss can be massive, as shown by another survey by Dark Heart Nursery Research which estimates that this disease can cause losses of up to 4 billion dollars per year for this industry.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t

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Comparison between a healthy plant (right) and a plant affected by HLVd (left), where the influence of the viroid on trichome production is clearly visible. Source: Dark Heart Nursery <\/figcaption>\n\t\t\t\t\t\t\t\t\t\t<\/figure>\n\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t
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Identifying HLVd Infection and Symptoms:<\/h2>\n

Although once we detect the symptoms it will be too late for that plant, by doing so we can save the rest of our crop.<\/strong><\/p>\n

HLVd systematically moves through the plant’s phloem over approximately six weeks. So, detecting it early is challenging as symptoms appear on leaves after the roots are already infected, leading to widespread infection throughout the plant, but these are the symptoms we should look for:<\/p>\n