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Tomato Fruit Abnormalities

Did you know that tomatoes can have horns? The following information will tell you why this happens.

Nashville, Ark. – Growers are sometimes bewildered when a tomato fruit grows a nose or horn, or even a pair of horns. Tomato horns or noses occur as a result of an error in cell division. A normal fruit has 4-6 locules when cut in half. When a few cells divide wrong they produce an extra locule. Since there is not enough room inside the fruit for the extra, a horn or nose protrudes from the fruit. Extended high temperatures (above 90 degrees during the day and 82-85 degrees during the night) predisposes the plant toward producing deformed fruit. Some of the older heirloom varieties are more susceptible.  This does not affect the taste of the fruit.

Catfacing is caused by anything that damages the bloom. This can be cold injury, insect, herbicide, or storm injury; however, typically this happens when planted too early in the spring.

Cracking is usually associated with excess amounts of water. The plant tissue swells with the water faster than the skin can grow and cracking occurs. Some varieties are more prone to cracking than others.

Yellow Shoulder is caused by fruit exposed to high temperatures during maturation and ripening. Some cultivars are more prone to it than others.

Graywall has been linked to potassium deficiency among other things. Black to dark brown necrotic tissue forms in the walls of tomato fruit infected with Graywall disease. In most cases only the outer walls are affected. Wall tissue may partially collapse, causing the outer skin of the tomato fruit to appear wrinkled. The area appears woody when cut, and the fruit is of poor quality. Graywall has been associated with Tobacco Mosaic Virus, low light conditions and cool weather as well as potassium deficiencies.

Sunscald or sunburn occurs during hot temperatures when protective foliage has been lost due to disease or insect feeding.

Sprouting inside fruit occurs in overripe fruit when seeds have reached maturity and the natural hormone, abscisic acid (ABA), is reduced. The tomato fruit allows sprouting inside because the seeds do not desiccate (dry out) in the moist environment inside the fruit. Some causes of seeds sprouting in tomatoes are long storage in cool temperatures (below 55 degrees), being overripe, potassium deficiency, and over fertilization with nitrogen.

This article was adapted from Plant Health Clinic News.

For more information, you can visit, or send an email to Howard County Extension office is still working and is there for all the residents in Howard County during this time. 

By Samantha Kroll
County Extension Agent - Agriculture
The Cooperative Extension Service
U of A System Division of Agriculture

Media Contact: Samantha Kroll
County Extension Agent - Agriculture
U of A Division of Agriculture
Cooperative Extension Service
421 N. Main Nashville AR 71852
(870) 845-7517


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