Tobacco Mosaic Virus (TMV) in Cannabis Plants: Symptoms and Prevention

The TM virus is unusual in cannabis plants but it can easily infect plants which will develop unusual growth and colors.
12 August 2020
4 min read
Tobacco Mosaic Virus (TMV) in Cannabis Plants: Symptoms and Prevention

  • 1. What is the tobacco mosaic virus?
  • 2. What does the tmv look like?
  • 3. Where is the tm virus found?
  • 4. Tobacco mosaic virus symptoms
  • 5. How to prevent it?
  • 6. How to deal with it?
  • 7. In conclusion

There’s no concrete evidence if the mosaic virus can indeed infect cannabis plants, although some growers swear it can. This happens because this virus is hard to come by and not everyone who suffers from it can test it in a lab and when the plants are tested, the results often come out as negative. 

Some growers say the symptoms are similar but occur because of different factors that stress your plants and others are certain it’s the virus, despite everything, one thing is certain: you don’t want your cannabis plants to get infected.

1. What is the tobacco mosaic virus?

The tobacco mosaic virus (aka TMV) is a virus widely known for affecting tobacco crops and it’s said it has spread to a lot of different plants, including the cannabis plant.


Tobacco Mosaic Virus

Tobacco mosaic virus on a tobacco leaf.

The TMV is a virus that affects a plant’s development, this virus can live in contaminated tobacco products like cigarettes1, contaminated plants, soil or even in bugs that contaminate your plant when they chew on it. This virus can affect a cannabis plant development, affecting yields and the quality of the buds.

2. What does the TMV look like?

It’s impossible to see the virus itself because it’s a microscopic being, but if your plant is affected you will surely see the signs, even though some of the symptoms can be confused for other things, the mosaic pattern your plant will develop is unique and super easy to identify.


Tobacco Mosaic Virus: signs

A different coloration on the leaves usually in a mosaic style is a sign your plants is infected with the tobacco mosaic virus.

If your plants show signs of leaf discoloration make sure your plants indeed are infected with the TMV and are not showing signs of overfeeding or any other plant deficiency that result in yellowing leaves. The tobacco virus cannot be removed and by treating other problems you'll be actually doing more damage.


3. Where is the TM virus found?

Because it’s a virus, it is inside the plant so you cannot see it, but there are several ways you can expose your plants to it.

Since it’s discovery, researchers have found out that the virus can infect more than 125 species of plants, and not only that, your plants can get infected if you plant them in infected soil or if a bug carrying the virus bites your plant, but the most common way of infection is plant to plant, by direct contact or via your hands after consuming tobacco products.

This means you have to be extremely careful when touching your plants after smoking tobacco because it’s the most common way most cannabis plants get infected.

4. Tobacco mosaic virus symptoms

The symptoms your plant shows after getting the TM virus will depend, the most common symptom2 is a mosaic-like pattern on some part of the leaves, this alone won’t damage your plants but because there’s no way to remove it from a plant, this specific plant won’t be suited for breeding.


Tobacco Mosaic Virus: symptoms

In some cases, plants infected with the tobacco mosaic virus will present deformed growth.

In more serious cases, you will see a mosaic pattern and some strange plant growth, this virus can cause the leaves to grow deformed, twisted and with a slower development, despite not damaging your plant, the unusual growth will affect the yields and depending on how your plant develops, it can also affect the quality of your harvest.


Mild Symptoms

Severe Symptoms

Distinct yellowing of the leaves veinsPlant deformation
Yellow spottingStunted growth
Mosaic pattern on the leavesTwisted leaves

Mild and severe symptoms caused by the tobacco mosaic virus.

Have in mind that you plant can show both mild and severe symptoms at the same time, the signs your plant gives will depend on the strain and can vary from case to case, even though some symptoms like twisted leaves and deformation can be caused by other things, the unique mosaic pattern will help you identify if your plant has the tobacco mosaic virus more easily.

5. How to prevent it?

There’s no way to prevent the tobacco virus other than always: 

  • Sanitizing your tools;
  • Buying soil or clones from a reputable vendor;
  • Washing your hands after smoking tobacco or dealing with infected plants.


Tobacco Mosaic Virus: prevention

Sanitizing your hands and tools is the best way to prevent the TM virus.

This virus can infect your plants by simply touching them so the best way to prevent it is always washing your hands before working on your garden and always make sure everything you bring in your garden is safe.

6. How to deal with it?

Unfortunately, there’s no way to remove the virus, once your plant or soil is infected because viruses cannot be controlled once they have been transmitted, this is why your best option is to prevent getting it.

If your plants get infected you should remove them from your garden, this not only applies to cannabis plants because the TM virus can infect all other plants in your garden and once it has spread throughout your garden, you’ll have to get rid of all the plants so as soon as you spot it, it’s better to remove it, remember the virus can even be transmitted by hand so it’s not worth it to risk it.


7. In conclusion

Even though the tobacco mosaic virus won’t damage your plants like bugs do, it can become a vicious cycle, infecting all your plants around. It’s crucial you take care of infected plants as soon as you spot them and if you don’t want to remove them, maybe isolate them and always wash your hands and every piece of equipment you use before touching other plants.

If you have seen it on your crops or have important information to share with fellow growers, please leave a comment in the comment section below!


External References:

1. Tobacco mosaic virus and para-tobacco mosaic virus in cigarettes - Wetter, C. (1975).

2. Tobacco mosaic virus - Rifkind, David & Freeman, Geraldine. (2005).

12 August 2020