How to Detect Tobacco Mosaic Virus in Your Plants
At one time or another, many growers who use tobacco products end up introducing tobacco mosaic virus into their gardens—sometimes without even knowing it! So is it really something to worry about?

You take the time to plant the seeds, provide them with enough light and water, and watch proudly as they germinate and become stronger, branch out and fill in the spaces between each stem. Then one day you notice a brown spot, then another and another, until your entire crop is covered with them. The leaf tips start to curve to the left, then downward, turning even browner until they dry to a crisp and crumble to the touch. You watch as even the fruits and flowers fall victim to a mysterious plant ailment
You start to wonder, “Why is this happening?” as you try different ways to solve the problem. You notice nothing seems to stop this destructive menace from covering your entire garden. Frustrated, you give up and remove the dead plant leaves, while cigarette smoke lingers nearby.
If this scenario sounds at all familiar, you have most likely introduced tobacco mosaic virus into your garden and it has now destroyed your plants. This virus cannot be treated, cannot be removed and cannot be stopped once discovered.
About Tobacco Mosaic Virus
Many growers who use tobacco end up introducing tobacco mosaic virus into their gardens at one time or another. The virus attaches itself to everything that it comes in contact with, including the smoke from the burned tobacco, and nothing is able to destroy it.
Tobacco mosaic virus comes from the tobacco plant and has been a problem of tobacco growers for decades. The virus attaches itself to the inner cell walls of the plants’ tissue, first forming on the outer layers of the leaves, and then slowly taking over the entire plant. Brown start to form on the plant leaves as they lose moisture and dry. The leaf tips turn towards the left and curl either under or upwards before drying out. This is followed by curling of the fruits or flowers themselves.
The vines, stalks and even the roots themselves shrivel away to nothing, leaving only the now dormant virus cells that are waiting to be transplanted into another garden. Most growers chalk these symptoms up to other causes, like deficiencies in the soil, water or nutrients, which means infections go largely undetected.
There are 11 known types of the mosaic viruses, all of which received their names from the mosaic patterns they leave as they destroy your garden. Tobacco, tomato, squash and zucchini mosaics are the four most common, with tobacco mosaic being the worse. Infected tomatoes, squash and zucchini plants are still safe for consumption if they are not too far gone (decayed).
Even the toughest tomatoes show the long thick scars that form along the outer skin, making them look like a burn or wound that is mostly healed. These tomatoes are still safe for consumption and are even found in stores.
Squash can also withstand most of the mosaic virus abuse, both inside and out, and are safe for consumption if they are not infected too much. You have to look out for the thick, open scars that will appear on the outer area near the stem. Infected zucchinis, on the other hand, start to dry up right at the flower stems while the skin erupts and splits open. These zucchinis end up being worthless.
Tobacco mosaic virus can infect any plant life with various results, yet perennials don’t appear to succumb to its effects. Different amino acids and starch compounds offer little for the virus to feed on, therefore making some plant species appear to be immune to its effects. Herbs such as cilantro, lemongrass, parsley and oregano show no effects of the virus, but are generally cultivated long before you see anything wrong. Plants that produce bulbs, such as onions, potatoes, garlic and the like, must also be harvested before the effects are noticed. However, since the virus attacks the root mass last, this is normally not an issue when it comes to consumption.
Preventing your garden from contracting tobacco mosaic virus is simple: don’t touch, smoke or use any sort of tobacco product. The virus can live in any soil or soilless medium. Tools used to till the soil, pH probes, hoses, buckets and containers—even indoor lighting fixtures—can carry the virus and spread it to the next crop. If your indoor or outdoor garden becomes infected with tobacco mosaic virus, you basically need to start over, making sure you’ve removed it from all areas where it may have lived.
Your equipment may be spreading the virus as well. If an infection returns after you’ve removed the affected plants and cleaned your tools, your equipment may need to be replaced.
For example, containers will show a thick, brown scale-like substance that won’t come off no matter how hard you scrub. Hydroponic and aquaponic systems show this scale buildup in the lines. Replacement of outdoor soil helps, but doesn’t always eliminate the virus completely.
So why all the fuss if tobacco mosaic virus has always been going on, yet causes no ill effects to consumers? Easy—it kills your garden, reducing the amount of crops that could have been used or sold, and it gets stronger and stronger every time it surfaces. So take charge and do what it takes to prevent this virus from infecting your garden.
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Written by Jeff Walters

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