Potato Pointers: New Disease, New Problems

Potato Pointers: In With The New: Zebra Chip

In the early days of 2000, potato growers in the southern U.S. were forced to begin dealing with a new problem in their crop. Vines were showing upwardly rolled leaflets, purple or yellow discoloration, aerial tubers, leaf scorch, and early senescence symptoms. At harvest, tubers were afflicted with vascular browning and areas of the internal tissues that were yellowish, translucent, or otherwise discolored. When affected tubers were sliced to make chips or fries, the symptomatic areas of the tubers turned dark brown when fried, yielding a finished product that showed alternating light and dark bands.

This characteristic symptom gave the name “Zebra Chip” to the new problem. This disease is more than a nuisance in chipping production, but other types of production, including French fry and even fresh potatoes, have the potential to be negatively affected.

Initial attempts to decipher what was causing the new disease met with failure, but scientists recognized early on that an insect called the potato psyllid was involved. After eliminating viruses and phytoplasmas (organisms like the ones that cause witch’s broom and purple top in potato) a team of scientists finally determined that the cause was an obscure, very difficult to work with bacterium. This bacterium belongs to the genus Liberibacter (the same group of bacteria responsible for citrus greening) but the final classification and nomenclature of the organism is still pending.

Potato Losses Mounting
There are no food or health safety issues regarding humans associated with the disease but, over the last 15 years, Zebra Chip has been responsible for some very serious losses to growers in Central America and in the southern U.S. Ominously, the disease was found late this summer in the Southern Columbia Basin of Washington and Oregon. In September, samples with characteristic symptoms were submitted to my laboratory in Idaho.

These also tested positive for Zebra Chip. Fortunately for the producers out here in the Pacific Northwest, the disease has only been found at low percentages in affected lots of potatoes.

Producers in the southern production areas where Zebra Chip has been at its most destructive have been able to utilize insecticide programs to manage the pysllid vector and are able to keep the disease in check At the current time researchers believe that the disease may not pose a significant threat to Pacific Northwest potato production or other more northerly productions areas due to the warm climate requirements of the vector.

Researchers also believe that seed potatoes are probably not responsible for movement of the disease. All of the major varieties currently produced are susceptible to Zebra Chip. Will we be able to breed resistant cultivars? Much remains unknown and only time and more research will answer the many questions posed by this new disease.

Zebra Chip has become important enough that a large group of researchers from across the country are working on it with funding from a Specialty Crops Research Initiative grant. Much of the work performed so far is reported on the grant website at http://agrilife.org/zebrachip. The site contains a wealth of information, including photos of vine and tuber symptoms as well as the problems encountered with finished product. A large and comprehensive research effort is currently underway. I’ll try to keep you all informed of new developments.


Leave a Reply

Featured Stories
Crop ProtectionAt Paramount Farming, Mating Disruption Pays Off
February 10, 2015
To say Brad Higbee is an expert in mating disruption, the use of pheromones to confuse target pests and reduce Read More
Crop ProtectionGrower Experienced In Biocontrols Says: Be Patient
February 4, 2015
The use of biocontrols in all aspects of agriculture is becoming more widespread. But incorporating biocontrols in a vegetable farming Read More
PotatoesAn Education On Potatoes [Opinion]
March 5, 2015
What is often a no-brainer for someone entrenched in the business of agriculture has to be explained — in detail — to some industry outsiders. Case in point: look at the rollercoaster ride potatoes have been on for several years. Read More
Insect & Disease Update#CitrusMatters Campaign Aims To Raise Awareness Of HLB In California
March 5, 2015
Bayer CropScience pledges up to $25,000 in support of continued research on a cure for citrus greening. Read More
CitrusNew Marvel Comic Book Reveals Origin Of Captain Citrus
March 5, 2015
Second installment of the Avengers Assemble series sets the stage for a new hero to save an orange grove under attack. Read More
FertilizerValent BioSciences Acquires Mycorrhizal Applications Inc.
March 4, 2015
Transaction fueled by technology platform that promises to bolster biorational business. Read More
EquipmentVegetable Growers Highlight Success With Precision Ag Technology
March 4, 2015
From prescriptive applications of water and fertilizers to seeders, precision technology has a place in any size operation. Read More
FruitsWeed Identification Guide Now Available For Growers
March 4, 2015
New free guide from Ohio State University offers high-definition pictures to help growers identify weeds. Read More
Crop ProtectionSurvey Shows Growers Seek New Strategies To Control Thrips And Other Major Pests
March 4, 2015
Growers surveyed at the 2015 Southeast Regional Fruit And Vegetable Conference list thrips as major pest concern, and are looking for new technologies to combat pests. Read More
Sweet CornAbbott & Cobb Sweet On New Sweet Corn Technology
March 3, 2015
SuperSeedWare gene type to aid varieties through marker-assisted selection. Read More
FruitsWest Coast Ports To Open With New Contract
March 3, 2015
Western fruit, vegetable industries lost millions when unable to export produce at ports. Read More
FruitsWorkshop Set In Florida To Help Grow Local Food Movement
March 2, 2015
Meeting part of nationwide effort to train people how to attain grants for USDA’s Farmers Market and Local Food Promotion programs. Read More
The Latest
PotatoesAn Education On Potatoes [Opinion]
March 5, 2015
What is often a no-brainer for someone entrenched in the business of agriculture has to be explained — in detail — to some industry outsiders. Case in point: look at the rollercoaster ride potatoes have been on for several years. Read More
Insect & Disease Update#CitrusMatters Campaign Aims To Raise Awareness Of HLB …
March 5, 2015
Bayer CropScience pledges up to $25,000 in support of continued research on a cure for citrus greening. Read More
CitrusNew Marvel Comic Book Reveals Origin Of Captain Citrus
March 5, 2015
Second installment of the Avengers Assemble series sets the stage for a new hero to save an orange grove under attack. Read More
FertilizerValent BioSciences Acquires Mycorrhizal Applications In…
March 4, 2015
Transaction fueled by technology platform that promises to bolster biorational business. Read More
EquipmentVegetable Growers Highlight Success With Precision Ag T…
March 4, 2015
From prescriptive applications of water and fertilizers to seeders, precision technology has a place in any size operation. Read More
FruitsWeed Identification Guide Now Available For Growers
March 4, 2015
New free guide from Ohio State University offers high-definition pictures to help growers identify weeds. Read More
Crop ProtectionSurvey Shows Growers Seek New Strategies To Control Thr…
March 4, 2015
Growers surveyed at the 2015 Southeast Regional Fruit And Vegetable Conference list thrips as major pest concern, and are looking for new technologies to combat pests. Read More
Sweet CornAbbott & Cobb Sweet On New Sweet Corn Technology
March 3, 2015
SuperSeedWare gene type to aid varieties through marker-assisted selection. Read More
FruitsWest Coast Ports To Open With New Contract
March 3, 2015
Western fruit, vegetable industries lost millions when unable to export produce at ports. Read More
FruitsWorkshop Set In Florida To Help Grow Local Food Movemen…
March 2, 2015
Meeting part of nationwide effort to train people how to attain grants for USDA’s Farmers Market and Local Food Promotion programs. Read More
Citrus18 Must-Have Apps For GenNext Growers
March 1, 2015
We asked about your favorite mobile applications, and here's what you had to say. Read More
Florida Ag ExpoGrowers Get The Lowdown On Cooling Crops
March 1, 2015
Demonstration shows how hydrocooling can help get the most out of fruits and vegetables once harvested. Read More
FruitsDon’t Be Afraid To Charge More For Value Of Agrit…
February 28, 2015
A higher admission price helps to sets a level of expectation and helps offset the costs of running a successful farm marketing operation. Read More
Apples & PearsCompany Responsible For First GMO Apples Is Sold
February 27, 2015
Okanagan Specialty Fruits, the company behind the world's first non-browning apples, fetches $41 million. Read More
Stone FruitPeach Training Systems Aren’t One-Size-Fits-All
February 27, 2015
Although pedestrian, ladderless orchards are increasing in California, growers in Pennsylvania are opting for tall V-training systems. Read More
FruitsNo Federal Water For California’s Central Valley Grower…
February 27, 2015
Skimpy snowpack leads Bureau of Reclamation to make unprecedented announcement that there will be a zero initial allocation for the second year in a row. Read More
Apples & PearsThe Recession That Keeps On Taking
February 27, 2015
We’re still seeing the aftermath of the Great Recession on consumers’ purchasing habits seven years later. Read More
Grower Achievement AwardSubmit Your Nomination For The 2015 Grower Achievement …
February 27, 2015
American Vegetable Grower magazine's annual award is designed to recognize an innovative operation that represents the spirit of excellence. Read More