Tobacco Mosaic Virus (TMV)
Oct 13, 2022 Fungi & Other Diseases
Discovering mottled patterns on your leaves and no deficiency in sight? You may have come across a tobacco mosaic virus in your cannabis plants. It’s the last disease you’d associate with marijuana (given its name), but it does surface under the right conditions.
Perhaps you’ve only heard about the tobacco mosaic virus that’s been ravaging different plant species for decades. Either way, educating yourself about something rare but possible is beneficial to the livelihood of your crops.
Simple contact between your plants could spread the virus, sending them off to the dumpster.
Learn how to eradicate or prevent this virus from destroying your crop by identifying the symptoms early.
What is the tobacco mosaic virus? (TMV)
The tobacco mosaic virus (also known as the tobamovirus or TMV) is a single-strand RNA pathogen. After its discovery in the 1800s in tobacco plantations, farmers began noticing similar symptoms in other crops.
TMV predominantly affects the plants in the Solanaceae family, like tomatoes, eggplant, potatoes, tobacco, and possibly, cannabis. Since its first discovery, the virus has already affected over 200 plant types.
Although there’s no scientific evidence that the disease exists in cannabis plants, some growers are certain that they’ve encountered it.
This virus is known for rapidly spreading on tobacco plants and could easily do the same to cannabis. It devastates plantations by affecting crop development, yields, and bud quality.
Being 100% certain of its presence on your plants isn’t guaranteed unless you have access to a lab for testing. The full circle of symptoms sometimes resembles that of other diseases or nutrient deficiencies.
Identifying the most obvious sign is your best chance at beating this disease. For example, do you notice some irregular patterns in your foliage? It could be a sign of the mosaic virus in your cannabis plants.
Microscopic channels (cuts and tears) on vegetation are gateways for this virus to enter the plants. Gene replication takes place, and the pathogen effectively takes over the crops. The leaves become discolored with a mosaic-like pattern.
A disease like TMV in cannabis is always seeking fresh hosts. Once the leaves dry out, and all signs of life are gone, it moves over to the next plant through contact.
The TMV doesn’t affect humans, whether they’re touching or inhaling infected plant material. People are, however, one of the primary carriers of the virus. Transmission quickly occurs by handling contaminated crops or tools and then healthy ones straight after.
The virus can also be spread by:
- Infected plants touching healthy ones
- Using soil where the virus has been dormant
- Crop-eating pests like broad mites
- Pollen from infected plants
- Seeds from dead plant material
- Dead leaves carrying the virus
- Plant sap that leaks onto clothing or gardening tools
- People who smoke infected tobacco or cannabis products around the crops.
That’s right, puffing while tending to your cannabis plants may potentially infect them. Manufactured tobacco products could still carry the virus, making exhaled smoke a threat. Who would’ve thought that even touching your plants after smoking can spread it too?
This virus is resilient and survives in plant material for a long time. According to reports, storing purified TMV stays up to 50 years in temperatures of 40℉.
If the coats of seeds become infected, it could alter the plant’s life cycle, from germination to harvest. Seedlings may seem to be experiencing some nutrient deficiencies because of similar symptoms to other problems.
The tobacco mosaic virus in cannabis thrives in hot, humid environments. Growing spaces with temperatures ranging from 104–122℉ create the ideal utopia for it to exist. The disease survives in moist soil for over a year and lives in dry substrates for much longer.
If you’re cultivating your marijuana crops indoors or in a greenhouse, be extra vigilant when examining your crops. Unfortunately, these setups create the ideal environment for infections like TMV to hang around.
What damage does TMV cause?
TMV causes irreversible damage to plants as well as the emotions of growers. The hardest blow is having to get rid of infected crops instantly. Since there’s no cure, removing the cause is your number one priority.
The excellent news is TMV doesn’t usually kill plants. The bad news is you’d need to remove them immediately when identifying symptoms.
It’s difficult to identify the early signs of the virus since the symptoms are similar to other deficiencies and diseases. When the plants begin looking sick and withered with mosaic patterns spread across their leaves, it’s time to bid them farewell.
Immediately discard plants showing symptoms to prevent cross-contamination among the crops. Identifying the tobacco mosaic virus during flowering is even more daunting.
No grower wants to throw away matured buds, but flavorless, low-quality flowers won’t do your smoking session any good either.
The plants take on abnormal growth patterns with irregularly shaped leaves that twist and curve. The yellowing of leaves means less green pigmentation is available for vital processes.
The tobacco mosaic virus interferes with chlorophyll production, which plants need for photosynthesis. If anything prevents plants from turning light into energy, they can’t metabolize proteins into food for healthy growth.
Infected seedlings are incredibly frail to this disease as it’s still discovering new growth patterns. Insufficient energy means weak plants, resulting in less tolerance to viral infections. However, older crops are a bit more resilient and can withstand ailments to a certain point.
Progressive TMV causes Cannabis root problems. If the pathogen interferes with the vascular system (xylem and phloem), the crops cant perform their natural feeding cycle.
- Xylem: Moves water and dissolved nutrients up towards the leaves.
- Phloem: Carries food converted from light to energy downwards to the roots.
Keep in mind that the heart of your crops stems from the roots. The plant can’t absorb nutrients if they’re unhealthy due to incorrect pH levels. Likewise, a lockout of nutes leads to many other problems, including making plants susceptible to viruses.
What does the tobacco mosaic virus look like?
Although the symptoms of the hemp streak virus are pretty clear, it’s easily confused with nutrient deficiencies. One singled-out sign of a TMV presence is the mosaic patterns that develop on the leaf surface.
The severity of the symptoms depends on age, environmental conditions, the pathogen strain, and the cannabis plant’s genetics. Opting for quality cannabis seeds puts you one step ahead of this virus.
Symptoms may vary on different plants, but let’s check out the most visible ones on marijuana plants.
On higher, younger foliage or even lower older ones, you’ll notice:
- Speckled, mosaic-like patterns show off the different green and yellow shades
- Yellowish lines, blotches, or veins
- Leaf veins become yellow
- Tips of leaves take on a burnt, brown effect
- Deep purple or black patches
- Small, curled, wrinkled leaves
- Foliage seems webbed, growing oddly
The rest of the plant may also present symptoms like:
- Wilted structure
- Slow growth at root level
- Maturation slows down (plants do not grow as fast as what they do without a virus present)
- Weak stems that become red or purple
- Small buds
- Conditioned to the viral strains, the flower on some marijuana crops appears mottled or streaked with visible symptoms of necrosis.
Remember that specific marijuana cultivars genetically produce plants with striped leaves and purple stems. It’s therefore always recommended to know precisely what seeds you’re buying.
The yellow shades are prominent on the deformed leaves, and the dark green areas have a thicker texture.
Mild infections show yellowing of leaf veins, while severe cases affect plant growth, yield production, and bud quality. Both can appear on the crops at the same time.
If you see any of the above symptoms on your crops, it could also be a result of:
- Inadequate temperatures
- Excess or shortage of nutrients
- Insecticides or herbicides
- Growth stimulators
- Watering weed plants too much, or too little
Sometimes Solanaceae plants are asymptomatic. The virus is present, but they don’t show any signs. On many occasions, cultivators only notice mottled leaves on plants in shaded areas.
If you’re not familiar with the signs of the virus, it’s always good to view “tobacco mosaic virus in cannabis” pictures. Alternatively, look at symptoms on other types of plants where the virus commonly occurs.
How to deal with TMV and prevent it
Sadly, there’s no tobacco mosaic virus cure for your plants. The only way to keep your growing space virus-free is by preventing it. If the unfortunate fate has fallen upon your marijuana crops, immediate eradication of infected crops is vital.
Getting rid of contaminated plant material is a process on its own. First, remove the entire pot from the area and discard the plant with the soil. Next, place it in a lock-tight bag far away from other plants.
Traces of TMV still exist on dry, dead leaves and plant material lying around the floor. Clear these up to prevent the virus from spreading to healthy crops.
Clean gardening tools like sheers, cutters, hose pipes, or water cans thoroughly with soapy water containing bleach solution. Doing this kills the virus on these surfaces and prohibits future spreading.
Once you’ve cleared your gardening space from infected plants, wash your hands thoroughly before touching anything. Change your clothes before moving between your crops to avoid cross-contamination.
Prevent TMV from destroying all your hard work by taking preventative measures to the next level. After hours of dedication, all you want is to grow large buds. Here are some extra tips.
- Always wash your hands before handling your cannabis plants.
- Avoid smoking any tobacco products around your crops.
- Change into different clothes before entering your indoor growing space.
- Be picky about who you allow around your marijuana plants, and always request them to follow protocols too.
- Buy cannabis seeds from trusted and reputable stores to ensure you’re cultivating plants with steller genetics.
- If you bring clones into your space, quarantine them before their introduction to the rest of the crops.
- Avoid using second-hand substrates. Buy soil from trusted sources.
- Checking pH in cannabis growing mediums is vital to prevent a nutrient lockout.
- Prevent watering problems, root problems, and nutrient deficiencies from occurring within your growing space.
Prevention is the only cure
Cannabis is so desirable that even viruses from tobacco plants find it appealing too. You don’t have to lose crops just because you didn’t wash your hands.
Since there isn’t a tobacco mosaic virus in cannabis cure, implement preventative measures, and you won’t ever have to look at mottled patterns on your foliage. With this disease, there’s no such thing as treating infected plants.
Keep your crops TMV-free and provide a sanitary haven within your growing space. Clean hands and clothing, a smoke-free zone, and sanitized gardening tools already put you a step ahead.
Grow from seed to avoid unwanted guests like the tobacco mosaic virus from candidly stepping into your garden. Being the primary caregiver from the start of life allows you to provide a healthy and safe environment. Remember, TMV loves waiting out in the soil to take over the next host.
Here at i49, we provide quality, healthy cannabis seeds with solid genetics. When you have crops with powerhouse genes on your side, things like the tobacco mosaic virus don’t stand a chance.