Lettuce Chlorosis Virus (LCV) is a crinivirus in the Closteroviridae family with a linear RNA genome encoding 14 proteins (Tzanetakis et al, 2013). This virus is spread via whitefly (Bemisia tabaci) and infects a variety of plant species, causing yellowing and necrosis of leaves, and reducing plant growth and yield.
LCV was recently identified in cannabis by a research group in Israel, who demonstrated the virus caused disease symptoms and could be spread by whitefly (Hadad et al, 2019). They also found that LCV spread from infected mother plants to clones, where they often showed more severe symptoms, but it did not spread through seeds.
The best methods for controlling LCV in cannabis cultivation are preventative measures, including implementing good hygiene practices, such as regularly cleaning and disinfecting tools and surfaces. Molecular testing is the best way to detect LCV and can detect presence of the virus before symptoms appear. If yellowing or stunting of leaves is observed, then this material should be collected and tested in the same way. If the virus is identified, it is important to take measures to prevent the spread of the virus to other plants in the cultivation area, which can be done by removing and destroying infected plants.
Biological control methods, such as the use of beneficial insects, can also be effective in reducing the impact of LCV in cannabis cultivation. For example, predators, such as ladybugs, lacewings, predatory mites and spiders or biological control agents like entomopathogenic fungi (EPF) can help to control populations of whitefly (Sani et al, 2020).
In conclusion, LCV is a plant virus that has a significant impact on the cultivation of cannabis. It is carried by one of the most widespread insect plants on the planet, meaning it can affect cannabis grown almost anywhere. LCV does not appear to be transmissible through seeds, so starting with seeds or tissue culture plants is an important first step towards maintaining a disease-free crop. If whiteflies are observed, use of beneficial insects can help to mitigate the potential spread of LCV by these vectors. By taking these steps, growers can help to ensure the health and yield of their cannabis crops, reducing the economic impact of this virus.
Hadad L, Luria N, Smith E, Sela N, Lachman O and Dombrovsky A (2019) Lettuce Chlorosis Virus Disease: A New Threat to Cannabis Production. Viruses, 11(9):802.
Sani I, Ismail SI, Abdullah S, Jalinas J, Jamian S, Saad N (2020) A Review of the Biology and Control of Whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae), with Special Reference to Biological Control Using Entomopathogenic Fungi. Insects, 11(9):619.
Tzanetakis IE, Martin RR and Wintermantel WM (2013) Epidemiology of Criniviruses: An Emerging Problem in World Agriculture. Front. Microbiol., 4:15.