§ News Releases §

October 22, 2004

Contact: Nora Olsen at (208) 736-3621 or norao@uidaho.edu in Twin Falls or communications specialist Marlene Fritz at (208) 384-0649 or mfritz@uidaho.edu in Boise.

UI Releases Publications on Storing Gem Russets,
Ranger Russets and Organic Potatoes

TWIN FALLS, Idaho-New publications on storing Gem Russets, Ranger Russets and organic potatoes are available this fall from University of Idaho Educational Communications.

Gem Russet, released in 2000, is 10 days shorter in dormancy than Russet Burbank. It accumulates lower concentrations of fry-darkening glucose when stored at 48ƒ Fahrenheit temperatures, but its glucose levels eventually surpass those of Russet Burbank when stored over time at 42 or 45 degrees. "Storage Management for Gem Russet Potatoes" includes a full discussion of Gem Russet's dormancy, sugar development and fry color as well as detailed recommendations for optimum storage.

Ranger Russet, released in 1991, must be managed carefully to prevent high glucose levels, dark fry color and mottling. "Vine Kill and Long-term Storage of Ranger Russet Potatoes" discusses the potential for optimizing processing quality by minimizing the time between vine kill and harvest. It describes optimum storage temperatures and suggests a greater time lag between application of the sprout inhibitor CIPC and processing.

"Ranger Russet tends to stand alone in terms of our vine kill recommendations," says co-author Nora Olsen, a UI Extension potato specialist. "It's also very susceptible to losing quality when it's exposed to cold temperatures. But we can store Ranger Russets with acceptable quality until June as long as we are familiar with some of the conditions that can compromise quality and try to avoid them."

Both publications are based on three years of research conducted by UI scientists at Idaho's Kimberly Research and Extension Center.

The third publication, "Organic and Alternative Methods for Potato Sprout Control in Storage," describes alternatives to CIPC for producers growing potatoes for organic markets or for overseas markets that prohibit CIPC use. Among these sprout suppressants are spearmint oil, peppermint oil, clove oil and hydrogen peroxide. These highly volatile compounds act by "burning" off sprouts and leave behind little or no residue. However, since new sprouts continue to develop, applications must be repeated frequently. The publication includes discussions of product effectiveness, application methods and precautions.

"These alternative products work well, but you need multiple applications and a good understanding of your crop's dormancy break and sprouting patterns," says Olsen. For growers selling into high-priced markets, however, the additional effort and expense can be worthwhile.

"Organic potatoes are a huge, ever-growing business, and there are a lot of questions out there about how producers can sell quality potatoes into markets that don't allow CIPC," she says.

All three publications can be downloaded from http://info.ag.uidaho.edu. They can also be ordered from UI Educational Communications by calling Kristin Johnson at (208) 885-7982 or sending e-mail to agpubs@uidaho.edu. 

10/22/04