Learning Center


Tomatoes Decoded

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No Need For A Decoder Ring

Tomatoes decoded! If you have shopped tomato plants, you have most likely noticed what seem like random letters after the tomato variety name. VFNTA, those mysterious letters associated with tomatoes are actually important and helpful to understand.   Sometimes located on the tag, or on the sign, these letters each represent abbreviations for disease resistance. Let’s decode those tomato tags and signs!

Let’s not  sugar coat it, tomatoes can be well……let’s say tricky.  Each year a gardener can experience a whole new situation when growing tomatoes due to all the possibilities of issues.  This is not to scare anyone away from tomato growing, because there is nothing better than a homegrown tomato from your garden. Tomatoes and mozzarella in the summer drizzled with olive oil, balsamic vinegar and fresh basil would not be the same with a store bought tomato.

Verticillium Wilt (V)

V stands for Verticillium Wilt resistance. The symptoms of this disease can seem like a natural death.  There are a few possible symptoms which include wilting during the day and recovering at night, yellowing of lower leaves often in a fan shape pattern, and leaves dying and then dropping off.


Once the plant is infected, destroy the plant. Avoid planting tomatoes in the same spot for 2 years.

At the beginning of the planting season, choose varieties that are resistant (indicated with a V) such as ‘Better Boy’, ‘Jet Star’, and ‘Rutgers’ to name a few.

Fusarium Wilt (F)

F stands for Fusarium Wilt resistance.  The symptoms of this disease can mimic Verticillium Wilt as mentioned above.  Fusarium Wilt is common in Arkansas due to hot weather.  The fungus has different races (F1) and (F2), also abbreviated (FF).  Send in a sample to the Plant Health Clinic for confirmation.


Once the plant is infected, destroy the plant.

Avoid planting tomatoes in the same spot up to 7 years.

Look at your soil pH.  It should be 6.5 to 7.  If it is below this range, apply lime.

When shopping for tomato plants, choose resistant varieties indicated with (F) or (FF).  ‘Parks Whopper and ‘Big Beef’ are two great options.

Nematodes (N)

On tomato tags or signs, N stands for nematode resistance which are small, very small worms that live in the soil. You would need a microscope to see them.  Affected plants may be stunted, grow poorly or they will wilt during the day and recover at night.  Roots affected by nematodes have knots/galls covering them.


Grow marigolds!  The smaller flowers of French marigolds are said to be better than the large flowers than the African varieties.  Marigolds have a natural compound that traps the nematodes, enticing them  rather than your tasty tomato plant.

Use common sense sanitation; nematodes can’t move far on their own in one growing season but moving the soil from an infected area to a new area can spread them pretty fast. If a severe nematode problem area has been identified, avoid doing anything that will move the soil or plant materials from that area to a ‘clean’ area.

Choose resistant varieties (as indicated by an N) such as ‘Superfantastic’, or ‘Beefmaster’.

Tobacco Mosaic Virus (T or TMV)

(T) or (TMV) indicates Tobacco Mosaic Virus resistance.  Symptoms can be small, curled or deformed leaves.  Infected plants may have a two tone light and dark green mottling coloration on the leaves. The fruit may be mottled in color as well.


Choose resistant varieties (as indicated with a T) such as ‘Bush Early Girl’, ‘Headmaster’, and ‘Goliath’.

Wash hands thoroughly after touching tobacco products.

Rotate where you plant tomatoes.

Alternaria (A)

Alternaria can appear in many forms. It is often dark brown or black spots on the stem, usually down low where the stem and the soil meet.  The pathogen can also infect leaves and look like a “target”.  Yellowish to brown spots with concentric rings, are easy to identify.  Warm, rainy weather exacerbates this fungus.


Try to keep the leaves dry when watering.

Choose resistant varieties (as indicated with an A) such as ‘Patio’, ‘Grape’, and ‘Juliet’

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More Letters Means More Resistance

A tomato can have more than one abbreviation after their name, the more letters they have, the more disease resistance the plants offer.  And on the other side of the spectrum, there are tomatoes that don’t have any resistance.  Many of the older heirloom types fall into this category.  However, many people still plant them because they enjoy the flavors!

Some good rules of (green) thumb when growing tomatoes is to water evenly, avoid watering leaves, rotate crop location, and allow for good air flow.  We will have more tomato growing tips in our upcoming post!  For more details on growing edibles in central Arkansas, visit this section of our Learning Center.

The University of Arkansas Division of Agriculture Research and Extension has many helpful tools; to learn more information on tomato diseases, follow this link.

The same division also has a Plant Health Clinic where samples can be sent to for further analysis and recommendations.