Four new russet varieties were released in 2015 from the cooperative USDA-ARS/University of Idaho potato breeding and variety development program in Aberdeen, Idaho. The releases were made jointly by the ARS and the experiment stations of Idaho, Washington and Oregon, which represent the institutions that comprise the Northwest (Tri-State) Potato Variety Development Program. The four new varieties are Targhee Russet (A01010-1), Payette Russet (A02507-2LB), Mountain Gem Russet (A03158-2TE) and Pomerelle Russet (A02062-1TE).
Targhee Russet
Targhee Russet is a dual-purpose variety with vine maturity similar to Russet Burbank. It produces a high yield of attractive, long tubers with brown-russeted skin. It has been trialed in both the western and eastern U.S., with higher marketable yields and fresh merit evaluation scores noted at most trial sites comparable to Russet Burbank. However, tuber dormancy is about 50 to 60 days shorter than Russet Burbank.
Targhee Russet is notable for its resistance to soft rot and has excellent resistance to most internal and external defects, including blackspot bruise and hollow heart. It has significantly higher protein and vitamin C contents than those of most standard varieties, indicating that it can provide enhanced dietary levels of these phytonutrients. Targhee Russet has moderate specific gravity and produces lighter colored fries out of storage than standard processing varieties. Industry evaluations of processing quality also indicate that Targhee Russet has good potential for producing fresh-cut fries.
Payette Russet
Payette Russet is a full-season processing variety with higher yields of oblong, medium-russeted tubers having higher protein content than those of the standard russet varieties. It has excellent cold-sweetening resistance, resulting in significantly lower reducing sugar concentrations and light fry color out of long-term storage than both Russet Burbank and Ranger Russet. Tuber dormancy for Payette Russet is about 30 days shorter than Russet Burbank. but it can be stored at 42 degrees, which significantly extends the dormancy period so that it is similar to Russet Burbank. Emergence is later than Russet Burbank’s, so Payette Russet needs at least a 120-day growing season for efficient production.
It has resistance to tuber malformations and most internal and external defects, including blackspot bruise and hollow heart. It has foliar and tuber resistance to late blight, as well as resistance to Verticillium wilt, early blight, common scab and corky ringspot (caused by tobacco rattle virus). However, it is susceptible to Fusarium dry rot and will need to be managed accordingly. Payette Russet is also notable for having a very high level of resistance to all potato virus Y (PVY) strains due to incorporation of the Rysto gene. The diversity of disease resistances exhibited by Payette Russet also make it a good candidate for organic production.
Mountain Gem Russet
Mountain Gem Russet is a medium- to late-maturing variety producing yields of oblong-long, medium-russeted tubers with higher protein content than those of standard potato varieties. It has consistently been the top-yielding selection in both the early and late western regional trials with excellent culinary quality.
Mountain Gem Russet has greater resistance to tuber late blight, tuber malformations and most internal and external defects than Russet Burbank. It maintains acceptable reducing sugar concentrations and fry quality when stored at 48 degrees and shows good potential for early processing. Tuber dormancy is about 70 days shorter than Russet Burbank. Fusarium dry rot susceptibility and weight loss in storage are similar to Russet Burbank. PVY susceptibility is similar to Russet Norkotah; however, mosaic symptom expression is typical for all three PVY strains, allowing seed growers to rogue infected plants and maintain quality seed. Mountain Gem Russet’s high early- and late-season total and U.S. No. 1 yields, coupled with good culinary and nutritional qualities, make it an excellent candidate for fresh market production.
Pomerelle Russet
Pomerelle Russet is an early-maturing fresh variety that produces moderately high early-season yields of long tubers with brown-russeted skin. It is notable for its very attractive, smooth skin and resistances to internal and external defects with a high percentage of U.S. No. 1 yield.
Relative to industry standard varieties Russet Burbank and Russet Norkotah, Pomerelle Russet has greater resistance to soft rot, corky ringspot and tuber infections from late blight. It also has much lower total glycoalkaloid concentrations and higher protein and vitamin C concentrations than Ranger Russet and Russet Burbank. It has moderate specific gravity and good resistance to sugar ends. It also has moderately long tuber dormancy, about 30 days shorter than Russet Burbank, and can maintain acceptable fry color for about 180 to 200 days in storage at 48 degrees, indicating some potential for processing out of short- or mid-term storage. However, its primary use appears to be as a high-quality, early fresh variety.
Information on seed availability for these new varieties is available from the Potato Variety Management Institute at www.pvmi.org.