Tips to store new spud varieties
University of Idaho researchers have released storage guidelines for 12 new potato varieties to aid growers in selecting varieties adapted to their storage and marketing programs.
“Russet Burbank used to be the only potato we dealt with,” says Tina Brandt, University of Idaho researcher at Kimberly, Idaho. “It is an industry standard and a favorite for both McDonald’s [fries] and fresh packers alike.” Storage management guidelines for the longtime favorite are well established.
The university’s new guide categorizes potatoes stored for use as fresh (for fresh market) or processing (for frozen processing). Brandt cautions that “our categorizations are guidelines only; growers are encouraged to pursue all avenues of marketing.”
Potato dormancy (storage period before sprouts appear) can be managed in several ways. “People want long dormancy,” Brandt says. “But we have great sprout inhibitors to lengthen that period. Some of these new varieties have a very short dormancy, so we need to get inhibitor applications on very early.”
High sugar levels in potatoes darken the color of french fries. “We worry a lot about sugar,” she says. Sugar levels can differ by variety, as well as storage management.
• Newer potato varieties replacing Russet Burbank.
• University of Idaho storage guide is available for 12 new varieties.
• Temperature requirements and dormancy length crucial for storage management.
Storage temperature effects on Russet Burbank are well-known. Typically, they are stored at 45 degrees F for process and cooler for fresh market, but many of the newer varieties store better with different temperature ranges. In general, cooler temperatures increase dormancy (a good trait) but also increases glucose content (an undesirable trait).
The guide lists several other characteristics such as dry rot, weight loss and mottling potential. “Currently, there are not many management tools to treat or prevent dry rot,” she says. “Bruising is a major factor, but there are some varieties that are more resistant.”
About weight loss, Brandt says, “Potatoes continue to respire [breath] during storage, which leads to some weight loss. Some varieties have higher weight loss than others.”
Mottling, a dark-colored flecking in fries, can also be controlled by variety and storage management. “We can see some mottling in Russet Burbank,” says Brandt. “But we can affect mottling with higher storage temperatures.”
Heat stresses in the field or in storage can also cause potatoes to sprout early. “There are different optimal storage temperatures for each of these varieties,” she says.
According to Brandt, the “biggest problem for processors to use these new varieties is acceptance by McDonald’s and Burger King.”
“We don’t really know, as researchers, the best use for each variety,” she says. “Growers have the best ideas for use for any variety.”
The complete guide can be found at www.kimberly.uidaho.edu/potatoes.
Tews writes from Shoshone, Idaho, and can be reached at firstname.lastname@example.org.
This article published in the April, 2010 edition of WESTERN FARMER-STOCKMAN.