Learn To Avoid These Six Tomato Disorders

Properly identifying physiological disorders in tomatoes can save time, money, and resources. North Carolina State University vegetable production specialist Chris Gunter provides the following tips on how to handle six major disorders.

1) Blossom End Rot: This disorder is often seen early on and is characterized by a premature reddening, and a leathery spot that develops and later dries out. It is not a disease, mentions Gunter, but a localized calcium deficiency. “This is caused by an interruption in the supply of water and calcium, which moves in the water stream of the plant,” he explains. “When that supply is stopped, the deficiency and thus symptoms can occur. The leathery spot can dry out and may sometimes turn fuzzy, which is not a disease, but a secondary infection.” It’s critical to get the plant to a pathologist for identification, Gunter adds.

Causes of blossom end rot include a local calcium deficiency, fluctuations in soil moisture, drought, root uptake, and excessive fertilizer.

Blossom End Rot on tomatoes. Photo credit: David B. Langston, University of Georgia, Bugwood.org.
Blossom End Rot on tomatoes. Photo credit: David B. Langston, University of Georgia, Bugwood.org.

2) Sun Scald: This problem occurs when tomato fruit are exposed to direct heat from the sun. This intense heat damages the fruit cells and can be lethal to the fruit tissue. To prevent scalding, Gunter advises maintaining proper foliage of the plant, which in turn will provide shade.

To reduce the chances of sun scald, make sure plants maintain healthy foliage to provide shade to developing fruit. Also, remove scalded fruit to redistribute the nutrients to undamaged plants, he adds.

3) Zippering: Zippering is when an anther sticks to a developing ovary, and causes damage as the fertilized ovary expands into tomato fruit. It usually starts when the fruit is green, and is later characterized by what literally appears to be a long zipper on the fruit that extends from the tip of the scar to the blossom end of the fruit. It sometimes gets so severe that a hole develops, leaving the fruit open to a variety of pathogens, adds Gunter. The only control is to choose varieties not prone to the disorder.

4) Fruit Cracking: Cracking of the fruit can either be radial or concentric. Radial cracks form near the stem and may appear all the way from the bottom to the tip of the fruit. Concentric cracks usually form on the shoulder of the fruit appearing as rings of brown scar tissue. Tomatoes are most vulnerable to cracking during the fruit expansion stage, and the problem could be a result of adverse environmental conditions, leading to slow growth and then returning to normal growth.

Some ways to prevent cracking include maintaining proper soil moisture and water supply during periods of hot, dry weather, says Gunter.

5) Graywall, or Blotchy Ripening: Externally, graywall is characterized by a lack of pigment in the developing fruit. Internally, it is characterized by dark necrotic areas that are usually in the vascular tissue of the outer walls. It typically develops when the fruit is still green, prior to harvesting, but it can also develop later.

Graywall can be caused by environmental conditions, which include prolonged cloudiness, low light, high humidity, and low temperatures. It can also be caused by high soil moisture, soil compaction, and excessive fertilization. Gunter suggests maintaining the crop with as few growth disruptions as possible because rapid changes during the production cycle cause the disorder.

“Catface” describes a tomato that has suffered major deformities. The exact cause is unknown, but temperatures below 60° F three weeks before bloom are considered a possible cause. Photo credit: Paul Bachi, University of Kentucky Research and Education Center, Bugwood.org.
“Catface” describes a tomato that has suffered major deformities. The exact cause is unknown, but temperatures below 60° F three weeks before bloom are considered a possible cause. Photo credit: Paul Bachi, University of Kentucky Research and Education Center, Bugwood.org.

6) Catface: “Catface” is a general term used to describe a tomato fruit that has suffered major deformities. There is typically no open wound and it usually appears on the blossom end as a large scar-like indentation. The exact cause of catfacing is unknown, but Gunter mentions low temperatures (below 60°F) three weeks before bloom as a possible contributor.

In the end, if only some fruits are damaged by the disorders mentioned here, Gunter reiterates that it is critical to get rid of damaged fruit in order to push the nutrients back into the more marketable ones as a way to cut losses.              

Topics:

Tomatoes Stories

TomatoesTomatoes: The Most Versatile Of All The Vegetables? [Opinion]
July 28, 2014
Tomatoes offer a variety of culinary options for consumers--from pizza to ice cream, the choices are many. Read More
TomatoesLearn To Manage Late Blight Resistance In Tomatoes
July 25, 2014
Researchers discuss how understanding the genetic changes in the late blight pathogen along with a proactive approach to control may help with resistance issues. Read More
TomatoesTomato And Carrot Flavored Ice Cream Hits Japanese Supermarkets
July 7, 2014
Häagen-Dazs released its Spoon Vege series of ice cream featuring Tomato Cherry and Carrot Orange flavors. Read More
TomatoesTomato Varieties For 2014
June 23, 2014
Check out a slideshow featuring 19 varieties from leading seed breeders and distributors to add to your collection. Read More
Crop ProtectionNew ‘Tomato MD’ App On Call For Sick Crops
June 17, 2014
Digital-based information resource from American Phytopathological Society available for iPhone and iPad use. Read More
TomatoesFord, Heinz Motivated To Turn Tomatoes Into Auto Parts
June 10, 2014
Skins of the fruit key to sustainability strategy for both companies. Read More
TomatoesManaging Botrytis And Sclerotinia White Mold In High Tunnel And Greenhouse Tomatoes
June 9, 2014
These two diseases can be severely damaging to tomatoes in protected environments if not managed properly. Read More

The Latest

TomatoesScientists Develop Tomato Plant That Can Tolerate 24 Ho…
August 12, 2014
Researchers discover a gene that could allow commercial tomatoes to tolerate light all day and night. Read More
TomatoesTomatoes: The Most Versatile Of All The Vegetables? [Op…
July 28, 2014
Tomatoes offer a variety of culinary options for consumers--from pizza to ice cream, the choices are many. Read More
Protected AgricultureFarm Research Helps New York High Tunnel Tomato Growers…
July 28, 2014
A four-page fact sheet is available to help high tunnel tomato growers fight leaf mold. Read More
TomatoesArcadia Biosciences Receives U.S. Patent For Extended S…
July 25, 2014
The new technology helps vine-ripened tomatoes stay fresh from farm to table. Read More
TomatoesLearn To Manage Late Blight Resistance In Tomatoes
July 25, 2014
Researchers discuss how understanding the genetic changes in the late blight pathogen along with a proactive approach to control may help with resistance issues. Read More
TomatoesTomato And Carrot Flavored Ice Cream Hits Japanese Supe…
July 7, 2014
Häagen-Dazs released its Spoon Vege series of ice cream featuring Tomato Cherry and Carrot Orange flavors. Read More
TomatoesTomato Varieties For 2014
June 23, 2014
Check out a slideshow featuring 19 varieties from leading seed breeders and distributors to add to your collection. Read More
Crop ProtectionNew ‘Tomato MD’ App On Call For Sick Crops
June 17, 2014
Digital-based information resource from American Phytopathological Society available for iPhone and iPad use. Read More
TomatoesFord, Heinz Motivated To Turn Tomatoes Into Auto Parts
June 10, 2014
Skins of the fruit key to sustainability strategy for both companies. Read More
TomatoesManaging Botrytis And Sclerotinia White Mold In High Tu…
June 9, 2014
These two diseases can be severely damaging to tomatoes in protected environments if not managed properly. Read More
Crop ProtectionStudy Reveals Origins Of Late Blight In Potatoes And To…
June 3, 2014
Study traces late blight to South America instead of Mexico, as previously thought, providing key insight to the pathogen’s genetic diversity and behavior. Read More
TomatoesLipman Opens Giant Packing Facility In Dallas
May 29, 2014
150,000-square-foot center consolidates operations from three existing locations. Read More
TomatoesLegendary Florida Tomato Grower Passes Away
May 15, 2014
Dewey Gargiulo, 84, focused on branding high-quality tomatoes. Read More
Business PlanningFree Trade Dynamics Deliver Possibilities, Perils To Ag…
April 23, 2014
In a global economy, growers should be aware of market threats and opportunities. Read More
TomatoesNew Study On Tomatoes Addresses GM Biochemical Concerns
April 10, 2014
Scientists compare biochemicals in GM foods and compare them to non-GM counterparts finding little difference between the two. Read More
Florida Ag ExpoFlorida Strawberry And Tomato Industries Seeking Soluti…
April 1, 2014
Change in game plan required as pressing market and trade dynamics threaten fruitful future. Read More
Crop ProtectionDon’t Take Chances With Chino Del Tomate Virus
March 26, 2014
Learn how to ID, the survival and spread, as well as management methods for this disease. Read More
TomatoesFree Grafted Tomato Plants For Ohio Growers
March 25, 2014
Grafted tomato plants will be made available free to growers on a first come first serve basis through The Ohio State University and The Ohio Agricultural Research and Development Center. Read More