Tips To Avoid Potato Bruising

As we head toward another harvest season and the mad rush it entails, now might be a good time for a few reminders and a short refresher on potato tuber bruising.

Mechanical damage to potato tubers can take the form of nicks, cuts, skinning, and bruising. All of these forms of damage can affect the final quality of your potatoes as well as the storability of the crop. In general, any type of damage that breaks the skin of the tuber is a concern because such damage provides a potential entry point for one or another of the long list of disease organisms that cause storage rots.

While nicks, cuts, and skinning are all relatively superficial (though some cuts can be very severe), bruising usually involves damage to fairly substantial portions of the tuber and may also go fairly deep. To make matters worse, some bruises remain invisible until the damaged tubers are cut.

Bruising Types
Three types of bruising occur in potato tubers. Two of these types of bruises, shatter bruise and blackspot bruise, are generally associated with the rigors of harvest, though potatoes can suffer bruise damage anytime they’re handled. The third type of pressure bruise actually occurs in the storage facility while the tubers are stationary.

Figure 1. Shatter bruise can be seen without cutting into the tuber. Tissue separation and periderm damage occur in potatoes harvested and handled when pulp temperatures are too cold. Photo(s) Credit: Dr Nora Olsen, University of Idaho, Kimberly.
Figure 1. Shatter bruise can be seen without cutting into the tuber. Tissue separation and periderm damage occur in potatoes harvested and handled when pulp temperatures are too cold. Photo(s) Credit: Dr Nora Olsen, University of Idaho, Kimberly.

1. Shatter bruise is the one type of bruise that can be observed without actually cutting into the tuber and examining the internal tissues. Shatter bruise is characterized by cracks and fissures in the tuber that break the skin (Figure 1). This type of bruise occurs readily in crisp, turgid tubers or those with a high-solid content and is often associated with potatoes that are harvested and handled when pulp temperatures are too cold.

Turgid tuber tissues respond to a physical blow by rebounding. As these forces reverberate through the tuber, they actually tear the tuber tissues apart, resulting in fissures in the tuber flesh and cracks in the skin.

2. Blackspot bruise is quite a bit different. In this case, the periderm and the somewhat more resilient tissues just beneath it will deform in response to a physical blow, but in this case, the skin doesn’t break, and the tuber tissues don’t get ripped apart. Instead, the energy from the mechanical insult is delivered to tissues deeper in the tuber. The damaged internal cells leak some of their cellular contents, and the enzymes and substrates released react with one another resulting in the internal grey to black discoloration associated with this bruise type (Figure 2).

Figure 2. Blackspot bruise, caused by a physical blow, is favored by warmer pulp temperatures and dry conditions.
Figure 2. Blackspot bruise, caused by a physical blow, is favored by warmer pulp temperatures and dry conditions.

Blackspot bruise is favored by warmer pulp temperatures or dry conditions that tend to leave tubers in a more flaccid state. It also appears more commonly near the stem end of the tuber.

3. Pressure bruise is very similar to blackspot in that tissue damage inside the tuber leads to discolored internal tissues. In this case, however, the mechanical force is supplied by the sheer weight of the potato pile bearing down on tubers at or near the bottom of the pile. External symptoms may appear in the form of flattened areas on the outside of affected tubers.

Recommendations For Management
Management begins with proper adjustment and operation of harvesting equipment and placement of padding in problem areas of the handling equipment. Avoid drops of more than 6 inches. Harvesting tubers in the recommended pulp temperature range of 45o F to 65o F will also help to reduce damage.

In general, both shatter bruise and blackspot bruise increase when pulp temperatures are too cold. Management of pressure bruise requires high humidity in the storage facility although reducing pile height — keep below 18 feet — can also minimize this type of bruise.

Topics: ,

Leave a Reply

Potatoes Stories
Potatoes
May 10, 2017
Florida Sweet Potato Farmers Learning How to One Up Wireworms
UF/IFAS researchers develop trapping systems for potent pest; studying other crop protection methods to help save revenue. Read More
Specialty potato varieties for Florida growers
Potatoes
April 30, 2017
Hot Potato Trends on Front Burner for Florida Growers
Annual UF/IFAS field day digs into the latest research and comes up with appealing solutions. Read More
Potatoes
April 25, 2017
Frustrated by Overwintering Culls and Volunteers? Blame Potatoes’ Wild Roots
It sometimes seems that culls and volunteers survive even winter conditions, while your desired crop needs coddling. Taking a look at how feral potatoes behave will give you insights that will help you get the results you need for your crop. Read More
Potato-beetle-eggs
Pest Control
April 25, 2017
How to Manage Three Key Potato Pests
Learn identification and control strategies to protect your crop. Read More
Florida potato plant in full bloom
Potatoes
April 7, 2017
Potato Field Day Set to Dig Up Solutions for Florida Farmers
The latest trends in production and crop protection at center of annual get-together. Read More
Crop Protection
April 5, 2017
Potato Psyllids are Gaining Resistance to Neonicotinoids
Neonicotionoids, a key weapon in the grower’s arsenal against potato psyllids, is becoming less effective, a team of researchers from Texas Read More
drip irrigation line closeup
More Vegetables
March 31, 2017
BMPs Paying off Big for Northeast Florida Farmers
Tri-County Agricultural Area projects to share $1.5 million in funding for continued conservation and nutrient management. Read More
Freeze protected blueberry bushes in Florida
Berries
March 25, 2017
Florida Blueberry Crop Escapes Slap from Late-Season Cold Snap
Freeze protection tactics prove fruitful as local producers look to gain from Georgia’s loss. Read More
Innate Gen 2 Atlantic potato compared to a Snowden FEATURE
Potatoes
March 8, 2017
3 GMO, Late-Blight-Resistant Potato Varieties Get EPA Approval
The introduced genetic material is from wild potato varieties that are resistant to late blight. Read More
Farm Management
February 28, 2017
Key Cabinet Picks Likely Good News for Growers
National Potato Council's John Keeling weighs in on how President Trump's picks for to head up EPA and Department of Agriculture will impact vegetable growers. Read More
sclerotinia
Disease Control
February 23, 2017
Spot Sclerotinia Before It Stops Your Vegetable Crop
Learn how to identify, the survival and spread, as well as management methods for this malady that goes by many names. Read More
Florida potato field in bloom.
Citrus
February 22, 2017
New Insecticide Available to Combat Sucking, Chewing Pests
Minecto Pro from Syngenta has received EPA approval for use in specialty and vegetable crops to control lepidopteran and other pests. Read More
Late blight shown in a tomato
Disease Control
January 19, 2017
Clues Found to Block Late Blight’s Blitz on Potatoes, Tomatoes
With food security at stake, breakthrough in genetic research could help prevent more strains of the deadly pathogen from entering the U.S. Read More
Potatoes
January 12, 2017
NPC’s 2016 Environmental Stewardship Award Goes to Vista Valley Ag
The farm plants a rotation of potatoes, barley, wheat, and alfalfa to reduce pest pressure and uses IPM techniques throughout the farming operation. Read More
Potatoes
January 11, 2017
Potato Growers Select NPC Leadership for 2017
Dwayne Weyers of Aspen Produce in Colorado was chosen as the next president of the National Potato Council. Read More
The Latest
Crop Protection
August 9, 2017
Why Some of the Most Dangerous Potato Di…
If you understand the role oxygen, and its lack, plays in potato diseases, you'll be better equipped to battle them. Read More
Potatoes
July 12, 2017
We Need to Fight for Fruit and Vegetable…
In the last 10 years, an alliance has used its combined voice to create programs like the Specialty Crop Research Initiative, the Specialty Crop Block Grant program, the Technical Assistance for Specialty Crops program, and others. Read More
Potatoes
June 5, 2017
Florida Growers and Researchers Unearthi…
More seeking to dig into production and profit of this appealing alternative superfood crop. Read More
Potatoes
May 10, 2017
Florida Sweet Potato Farmers Learning Ho…
UF/IFAS researchers develop trapping systems for potent pest; studying other crop protection methods to help save revenue. Read More
Potatoes
April 30, 2017
Hot Potato Trends on Front Burner for Fl…
Annual UF/IFAS field day digs into the latest research and comes up with appealing solutions. Read More
Potatoes
April 25, 2017
Frustrated by Overwintering Culls and Vo…
It sometimes seems that culls and volunteers survive even winter conditions, while your desired crop needs coddling. Taking a look at how feral potatoes behave will give you insights that will help you get the results you need for your crop. Read More
Pest Control
April 25, 2017
How to Manage Three Key Potato Pests
Learn identification and control strategies to protect your crop. Read More
Potatoes
April 7, 2017
Potato Field Day Set to Dig Up Solutions…
The latest trends in production and crop protection at center of annual get-together. Read More
Crop Protection
April 5, 2017
Potato Psyllids are Gaining Resistance t…
Neonicotionoids, a key weapon in the grower’s arsenal against potato psyllids, is becoming less effective, a team of researchers from Texas Read More
More Vegetables
March 31, 2017
BMPs Paying off Big for Northeast Florid…
Tri-County Agricultural Area projects to share $1.5 million in funding for continued conservation and nutrient management. Read More
Berries
March 25, 2017
Florida Blueberry Crop Escapes Slap from…
Freeze protection tactics prove fruitful as local producers look to gain from Georgia’s loss. Read More
Potatoes
March 8, 2017
3 GMO, Late-Blight-Resistant Potato Vari…
The introduced genetic material is from wild potato varieties that are resistant to late blight. Read More
Farm Management
February 28, 2017
Key Cabinet Picks Likely Good News for G…
National Potato Council's John Keeling weighs in on how President Trump's picks for to head up EPA and Department of Agriculture will impact vegetable growers. Read More
Disease Control
February 23, 2017
Spot Sclerotinia Before It Stops Your Ve…
Learn how to identify, the survival and spread, as well as management methods for this malady that goes by many names. Read More
Citrus
February 22, 2017
New Insecticide Available to Combat Suck…
Minecto Pro from Syngenta has received EPA approval for use in specialty and vegetable crops to control lepidopteran and other pests. Read More
Disease Control
January 19, 2017
Clues Found to Block Late Blight’s…
With food security at stake, breakthrough in genetic research could help prevent more strains of the deadly pathogen from entering the U.S. Read More
Potatoes
January 12, 2017
NPC’s 2016 Environmental Stewardship Awa…
The farm plants a rotation of potatoes, barley, wheat, and alfalfa to reduce pest pressure and uses IPM techniques throughout the farming operation. Read More
Potatoes
January 11, 2017
Potato Growers Select NPC Leadership for…
Dwayne Weyers of Aspen Produce in Colorado was chosen as the next president of the National Potato Council. Read More