Potato seed piece treatment in Washington

Although a slight amount of seed piece decay occurred, blackleg did not develop, and yield was not reduced in trials with untreated seed pieces of Norgold Russet and Russet Burbank in 1968 and 1969. Chemical seed piece treatments reduced seed piece decay, but did not increase yield. Storing untreated cut seed of these two varieties up to 5 days at 50–90 F (10–32C) and 35–86% relative humidities with adequate ventilation did not affect seed piece decay, blackleg, or yield.     

Effects of plant population on the performance of seven varieties in the Klamath Basin of Oregon

The effects of seed spacing on the performance of seven potato cultivars grown at the Klamath Experiment Station in Southern Oregon were evaluated from 1987 through 1991. Seed spacings in 81 cm rows included 17, 22, and 30 cm, representing the range of local commercial practice. Most varieties evaluated experienced highly significant increases in tuber size as plant populations were decreased. Atlantic was the only variety that demonstrated reduced total yield or total yield of U.S. No.1’s at low populations. Plant population had limited effects on the incidence of hollow heart and no effect on specific gravity in most varieties. Optimum seed spacing for fresh market or processing crops ranged from 17 cm for Century Russet and Atlantic to 30 cm for Russet Norkotah. Century Russet, Gemchip, and Atlantic produced the highest marketable yields. Russet Norkotah experienced the largest yield variability between years. Atlantic and Gemchip were the most consistent in yield of U.S. No.1’s over years     

Fresh Market Evaluation of Six Russet-Type Potato Varieties and Four Russet Norkotah Strains

In 2016, Russet Norkotah was the second most widely grown potato variety in the US; however, recent research has identified alternatives with excellent production economics. During 2011–2013, fresh market variety research was conducted in the Columbia Basin of central Washington, a long-season production region. Russet Norkotah was compared to five varieties–Classic Russet, Mountain Gem Russet, Russet Burbank, Targhee Russet, and Teton Russet–and four sub-clonal strains–CO-3, CO-8, TX-278, and TX-296–derived from Russet Norkotah. Each variety was evaluated for early- (104 days between planting and vine kill) and late- (150 days between planting and vine kill) harvest tuber size profile, grade, and yield, grower economic value, susceptibility to blackspot bruise and shatter bruise, emergence, stem and at-harvest tuber numbers, tuber length-to-width ratios, and quality. When harvested early, Classic Russet and Mountain Gem Russet produced 30% and 15% more gross revenue than Russet Norkotah, respectively. All other varieties and Russet Norkotah strains except CO-3 produced as much early-harvest gross revenue as Russet Norkotah. CO-3 early-harvest revenue was close to 50% lower than that of Russet Norkotah. All varieties and Russet Norkotah strains produced significantly greater late-harvest yields and gross returns than Russet Norkotah. Late-harvest gross revenue for Targhee Russet and Mountain Gem Russet was 38% and 34% higher than Russet Norkotah, respectively. Classic Russet, Mountain Gem Russet, Targhee Russet, and Teton Russet had significantly more shatter bruise following the late harvest than Russet Norkotah and all Russet Norkotah strains. Russet Burbank was among the most susceptible to blackspot and Targhee Russet the least, with 32% and 2.1%, respectively. If bruising is mitigated, Mountain Gem Russet, Classic Russet, and Teton Russet may be suitable alternatives to Russet Norkotah and Russet Norkotah strains for both early and late harvests.     

Century Russet: A high-yielding fresh market cultivar with verticillium resistance

Century Russet, a high-yielding, late-maturing variety suitable for fresh tablestock use, was jointly released in 1995 by Agricultural Experiment Stations in Oregon, Idaho, Washington, Colorado, California, and Texas and the USDA Agricultural Research Service. Extremely high yields have been observed for Century Russet in variety trials conducted in Oregon and throughout the western United States under a wide range of soil and climatic conditions. Century Russet produced 40 percent higher marketable yields than Russet Burbank and 67 percent higher marketable yields than Russet Norkotah in 11 regional trials conducted over a three-year period in sevenwestern states. Uniform tuber shape, high yields of count carton sizes, and attractive tuber appearance make Century Russet well suited for the fresh market industry. It is not recommended for chipping or processing into frozen products because of low solids and dark fry color. Century Russet is highly resistant toVerticillium wilt and consistently develops less hollow heart, brown center, and other internal defects than Russet Burbank. It requires more time between vine kill and harvest than Russet Burbank for adequate tuber maturity and skin set. Bruised Century Russet tubers are susceptible to early blight andFusarium infection.     

Effect of seed piece population on the yield and processing quality of Russet Burbank potatoes

The effect of seed piece population on tuber yield, size distribution and processing quality of Russet Burbank potatoes grown under nonirrigated conditions in southern Manitoba from 1983 to 1987 was determined. Seed pieces were planted at 21.7, 26.3, 33.3 and 45.5 thousand seed pieces per hectare, and plant emergence generally exceeded 90% of the seed piece population. Marketable tuber (greater than 5 cm in diameter) yields were not affected by seed piece population. As population increased, however, the number of harvested tubers increased and average tuber size decreased, which resulted in a decreased yield of premium tubers (greater than 284 g) and an increased yield of small tubers (less than 5.0 cm in diameter). Specific gravity, the incidence of hollow heart in maingrade (5 cm in diameter to 284 g in weight) and premium tubers, and fry color were not significantly affected by seed piece population. In the one trial tested, sucrose content decreased as population increased, however, this was not reflected in improved fry color after storage.     

Effect of whole seed tuber size and pre-plant storage conditions on yield and tuber size distribution of Russet Burbank

Field experiments were conducted in 1995, 1996, and 1997 at Agriculture and Agri-Food Canada’s Harrington Research Farm to assess the effect of whole seed tuber size and pre-plant seed storage conditions on processing yield (> 51 mm dia.) of potato (Solanum tuberosum L. cv Russet Burbank). Following commercial storage, seed tubers were stored at 4.4 C then subjected to one of three pre-plant treatments: (1) planted directly from storage, (2) held at 10 C for 3 wk before planting, or (3) green-sprouted for 3 wk before planting. Five sizes of whole seed were used (28, 42, 56, 70, and 84 g) with a variable size cut seed treatment added for comparison. Plots were harvested 138,134, and 131 days after planting in 1995, 1996, and 1997, respectively. Cut seed produced a higher yield of tubers > 51 mm diameter in comparison to all whole tuber seed sizes, with the exception of the 28 and 56 g sizes. In terms of total yield, the 28and 42-g whole seed tubers yielded significantly less than all other seed sizes examined. Warming or greensprouting seed tubers prior to planting did not increase tuber yield. The larger whole seed tuber sizes tended to result in greater numbers of stems and tubers per plant. To maximize marketable yield of Russet Burbank planted from whole seed tubers, it is recommended that the seed be between 28 and 42 g in size. Accepted for publication 25 May 2004.     

Nitrogen fertilization of irrigated Russet potatoes in southcentral Alaska

Allagash Russet, BelRus, Frontier Russet, HiLite Russet, Russet Norkotah and Russet Burbank were evaluated with preplant N fertilizer levels of 0, 67, 134, 201, and 201 kg N/ha in a split application on a Knik silt loam in 1990 and 1991 near Palmer, Alaska. BelRus and Russet Norkotah yielded less marketable tubers than the other cultivars and Russet Burbank performed well under warm, dry 1990 conditions and poorly when conditions were cool and wet (1991). Allagash, HiLite and Frontier Russets were consistent producers with marketable tuber yields averaging 35.4, 32.3, and 32.2 t/ha, respectively. Marketable tuber yield was maximized with approximately 175 kg total N/ha (residual soil plus applied) and approached 43 t/ha in 1990. Splitting the N application had no significant effect on tuber yield. Newly released russets appear promising for commercial Alaska producers.     

Teton Russet: An Early-Maturing,Dual-Purpose Potato Cultivar Having Higher Protein and Vitamin C Content,Low Asparagine,and Resistances to Common Scab and Fusarium Dry Rot

Teton Russet is an early-maturing, medium-russeted, potato cultivar with high merit for both fresh-pack and processing. In early harvest trials in the Pacific Northwest, Teton Russet had total yields similar to Russet Norkotah, and higher than Ranger Russet and Russet Burbank. Marketable yield of Teton Russet in the early harvest trials was also comparable to or higher than Russet Norkotah in Washington and Oregon, and higher than Ranger Russet and Russet Burbank at these sites, as well as in Idaho. In full-season trials, while total yield of the earlier-maturing Teton Russet tended to be lower than Ranger Russet and Russet Burbank, marketable yield was generally higher than Russet Burbank across the majority of sites due to its higher percentage of U.S. No. 1 tubers. Teton Russet is suitable for processing, with acceptable fry color following up to 8 months of storage at 8.9 °C. Uniformity of fry color was also very consistent. Teton Russet has shown lower levels of the amino acid asparagine relative to Ranger Russet and Russet Burbank which may contribute to lower acrylamide levels in French fries and other processed potato products. Teton Russet is notable for having resistance to common scab (Streptomyces spp.) and Fusarium dry rot, and is moderately resistant to tuber net necrosis. Analyses have also shown Teton Russet to have significantly higher protein levels than Russet Norkotah, Ranger Russet, and Russet Burbank, as well as higher vitamin C content than Russet Norkotah and Russet Burbank. Teton Russet was released in 2011 by the USDA-ARS and the Agricultural Experiment Stations of Idaho, Oregon, and Washington, and is a product of the Pacific Northwest Potato Variety (Tri-State) Development Program.     

Hill to hill variations in tuber yield of potatoes in Alberta

The hill to hill variation in tuber yield and mainstem number was studied on 18 potato farms. There were up to 14-fold differences in the tuber yield per hill among plants of Norland, Russet Burbank, Norchip, Carlton and Alaska Red. The mainstem number was more variable than tuber weight per hill in Norland, Russet Burbank and Alaska Red. However, the opposite was true in Norchip and Carlton. In nearly all comparisons, the number of tubers per hill was less variable than tuber weight and mainstem number per hill. The total variation in tuber weight found in about 50% of the samples could be explained by the variance of hills within rows. Even in samples where an added variance component due to differences among rows was present, relatively more variation occurred within than among rows. The correlation coefficients between the number of mainstems and tuber weight per hill were positive but significant (P&< 0.05) only in Norland and Norchip. The correlation coefficients between the number of mainstems and number of tubers per hill were also positive but slightly higher and significant (P<0.01) in all 5 cultivars. The coefficient of determination values indicated that variation in cut seed piece weight explained only about 10% of the total variation in tuber weight harvested per hill. At a spacing of 30 cm within the row, a major proportion of hill to hill variation in tuber yield had to be explained by factors other than the seed piece weight.     

Influencing seed tuber yield of Ranger Russet and Shepody potatoes with gibberellic acid

Freshly-cut seed pieces of the potato cultivars Ranger Russet and Shepody were dipped in 0, 0.5, 1 or 2 mg/1 Gibberellic Acid (GA₃) prior to planting. GA₃ treatments increased stem and tuber numbers per hill of both cultivars and shifted tuber size profile toward the production of more seed-sized (up to 226 g) tubers and fewer large (greater than 340 g) tubers. The effect of GA₃ on reducing average tuber size was similar for the two cultivars. Total tuber yields were not affected. A 2 mg GA₃/1 seed piece dip decreased the yield of US#1 tubers in Ranger Russet primarily due to a significant increase in yield of tubers less than 226 g. Also, yields of culls were greater after a 1 mg GA₃/1 seed piece treatment, suggesting Ranger Russet is sensitive to this concentration of GA₃. One and 2 mg GA₃/1 seed piece dips to Shepody increased yields of tubers less than 113 g by 93% and reduced the yield of tubers greater than 340 g by 25% to 50%. GA₃ at 1 to 2 mg/1 may be useful in the production of seed potatoes with the cultivar Shepody which tends to produce many large tubers.     

Pomerelle Russet: an Early Maturing Potato Variety with High Yields of U.S. No. 1 Tubers Suitable for Fresh Market and mid-Storage Processing and Tolerance to Potato Mop-top Virus

Pomerelle Russet is an early maturing fresh potato variety, which produces moderately high early-season (95–110 days after planting) yields of long tubers with brown-russet skin. It is notable for its very attractive, smooth tubers and resistances to internal and external defects with a high percentage of U.S. No. 1 tubers. Fresh merit ratings for Pomerelle Russet in trials conducted in Idaho, Oregon and Washington were consistently higher than Russet Burbank and Russet Norkotah. Early harvest yields for Pomerelle Russet are generally comparable to Russet Norkotah with a higher percentage of U.S. No. 1 tubers. Compared to Russet Burbank and Russet Norkotah, Pomerelle Russet has greater resistance to Potato mop-top virus, soft rot, corky ringspot and tuber infections from late blight. It also has higher protein and vitamin C concentrations than Ranger Russet, Russet Burbank and Russet Norkotah, indicating that it can provide an enhanced level of dietary protein and vitamin C relative to these standard potato varieties. Pomerelle Russet has moderate specific gravity and good resistance to sugar ends. It also has moderately long dormancy, about 30 days shorter than Russet Burbank. Average post-harvest processing ratings for Pomerelle Russet were similar to Ranger Russet and greater than Russet Burbank. Pomerelle Russet also has maintained acceptable fry color for about 180–200 days in storage at 8.9 °C, indicating potential for processing out of mid-term storage, with improved fry color uniformity relative to industry standards. However, its primary use appears to be as a high quality, early fresh variety.     

Russet Legend: A full season long Russet for processing and fresh market use

Russet Legend, a moderately late maturing variety especially suitable for frozen French fry processing but also acceptable for tablestock use (boiling, and baking), was jointly released by the Agricultural Experiment Stations of Oregon, Colorado, Idaho, and Washington, and the U.S. Department of Agriculture in 1998. Russet Legend was evaluated in irrigated trials in Oregon from 1988 to 1997, and in western regional trials from 1990 to 1992. Total yields were similar to those of Russet Burbank, but Russet Legend produced higher marketable yields. In three years of regional trials at up to 13 locations in seven western states, Russet Legend averaged 47.3 Mg/ha marketable yield compared with 36.5 Mg/ha for Russet Burbank and 33.6 Mg/ha for Russet Norkotah. Russet Legend has consistently achieved lighter fry color and higher specific gravity than Russet Burbank. Russet Legend is less susceptible toVerticillium wilt than Russet Burbank or Russet Norkotah. It is susceptible to PLRV and net necrosis, and expresses PVY foliar symptoms clearly. Russet Legend is less susceptible to tuber infection and decay caused byPhytophthora infestans than Ranger Russet and Russet Norkotah. Russet Legend is less susceptible to hollow heart, brown center, growth cracks, and sugar ends than Russet Burbank     

Wallowa Russet: A full season long Russet for processing and fresh market

The Agricultural Experiment Stations of Oregon, Idaho, and Washington and the U.S. Department of Agriculture jointly released Wallowa Russet in 2002. This late maturing variety is most suitable for frozen french fry use, but may find limited fresh market potential because of outstanding flavor and texture when baked. Wallowa Russet was evaluated as AO87277-6 in Oregon irrigated trials from 1993 through 1999, and in western regional trials from 1997 through 1999. Averaged over 13 locations in seven states, Wallowa Russet produced total yields of 55.6 mt/ha compared to 53.5 and 45.7 mt/ha for Russet Burbank and Russet Norkotah, respectively, and U.S. No.1 yields of 44.4 mt/ha compared to 30.7 and 36.0 mt/ha for Russet Burbank and Russet Norkotah. Specific gravity is consistently higher for Walowa Russet than for Russet Burbank and fry color is as light or lighter; sugar end development is less than that observed in Russet Burbank. Wallowa Russet is similar to Russet Burbank in susceptibility toVerticillium wilt, foliar early blight (Alternaria solani), and potato leafroll virus (PLRV). However, Wallowa Russet develops less net necrosis than Russet Burbank from PLRV infection. Wallowa Russet is more susceptible to common scab (Streptomyces scabies) than Russet Burbank. It has moderate resistance to potato virus Y (PVY). Tubers of Wallowa Russet are less susceptible to tuber infection and decay caused by potato late blight (Phytophthora infestans) than Russet Norkotah and Ranger Russet. Wallowa Russet has less hollow heart, brown center, blackspot bruise, and fewer growth cracks than Russet Burbank but is more susceptible to shatter bruise. Vitamin C is higher for Wallowa Russet (30.4 mg/100 g fresh weight) than for Russet Burbank (21.9) or Russet Norkotah (22.0), and protein content averaged 5.6% compared to 4.7% and 4.9% for Russet Burbank and Russet Norkotah, respectively.     

Effect of seed tuber and seed piece size on growth and incidence of hollow heart in Norgold Russet potatoes

Small seed pieces decreased yield and number of tubers. Both seed tuber and seed piece size affected the percentage of tubers with hollow heart. Hollow heart increased from 14 to 22% as the seed tuber size increased from 57 to 228 g and decreased from 27 to 19% as the seed piece size increased from 28 to 57 g. The least hollow heart (11%) occurred in tubers of plants grown from 57 g whole seed pieces and the most (26%) in tubers of plants grown from 228 g seed tubers cut into 28 g seed pieces. Hollow heart was positively correlated with the mean tuber size and negatively correlated with the number of mainstems per hill, total yield, and total number of tubers.     

Detection of potato leafroll virus by visual inspection,direct tissue blotting and ELISA techniques

Greenhouse-grown Russet Burbank and Russet Norkotah plants were tested for potato leafroll virus (PLRV) by visual examination, enzyme-linked immunosorbent assay (ELISA) and direct tissue-blotting assay (DTBA). Visibly infected and healthy plants were obtained from excised eyes of tubers submitted for winter certification tests. Each plant was sectioned into leaf, petiole, stem, root, seed piece, and tuber portions. Tissues were blotted on a nitrocellulose membrane for DTBA and then homogenized for use in a double-antibody sandwich ELISA system. Agreement between the two serological detection methods and with visual readings was high for petioles and stems, but lower for leaf, tuber and root tissues. Comparison of DTBA with ELISA and with visual plant symptoms suggest that DTBA can be used with the same accuracy as ELISA for detecting PLRV in stems and petioles     

Effects of Planting Configuration and In-Row Plant Spacing on Photosynthetically Active Radiation Interception for Three Irrigated Potato Cultivars

Research studies have evaluated the production of potatoes (Solanum tuberosum L.) grown in conventional and bed planting configurations. However, intercepted photosynthetically active radiation (PAR) from these planting configurations has not been quantified. A study conducted in 2008 and 2009 quantified and compared the intercepted PAR from three planting configurations (four row conventional ridged-row [4RC], five row bed [5RB], and seven row bed [7RB]), and from different plant spacings of cvs Russet Burbank, Russet Norkotah, and Ranger Russet potatoes under sprinkler irrigation. A second study was conducted in 2007 to evaluate the relationship between PAR and leaf area of Russet Norkotah and Russet Burbank for the three planting configurations. These studies were conducted at the USDA-ARS Northwest Irrigation & Soils Research Lab in Kimberly, ID, on a Portneuf silt loam (coarse–silty mixed mesic Durixerollic Calciorthid). The canopy of Russet Norkotah and Ranger Russet potatoes grown in 5RB and 7RB planting configurations intercepted more PAR during the early vegetative and tuber initiation growth stages compared to the 4RC planting configuration at equal populations in 2008 and 2009 at all measurement dates. The canopy of Russet Burbank intercepted more PAR during the early growth stage in 2008 when planted in the bed planting configurations compared to the 4RC planting configuration, but not on the July 17, 2008 and July 9, 2009 dates. The canopy cover of Russet Burbank potatoes planted in the 4RC planting configuration tended to catch up with the bed planting configurations quicker than the other two cultivars. In general, the quantity of PAR intercepted as affected by planting configuration did not influence total tuber yield and other measured production variables. Cumulative PAR interception 0–72 days after planting (DAP) was increased 35%, 38%, and 32% for the 5RB and 65%, 69%, 23% for the 7RB relative to the 4RC planting configuration for Ranger Russet, Ranger Norkotah, and Russet Burbank, respectively. Cumulative PAR interception for the season was increased 15%, 16%, and 4% for the 5RB and 23%, 23%, 5% for the 7RB relative to the 4RC planting configuration for Ranger Russet, Ranger Norkotah, and Russet Burbank, respectively. The relationship between intercepted PAR and leaf area for Russet Norkotah during the early vegetative and tuber initiation growth stages was significantly different between the three planting configurations, with intercepted PAR at a given leaf area in the order of 7RB>5RB>4RC. For Russet Burbank, the relationship was significantly different for the 5RB and 7RB compared to 4RC planting configuration only, with intercepted PAR at a given leaf area in the order of 7RB=5RB>4RC.     

Selection, evaluation, and identification of improved Russet Norkotah strains

Strain (sub-clonal, line, or intraclonal) selection for certain characteristics within some potato varieties has been very successful e.g. improved skin type (Russet Burbank from Burbank), improved skin color (Red LaSoda from LaSoda; Red Norland and Dark Red Norland from Norland), and improved vine vigor and yield (Norgold Russet M from Norgold Russet). In 1989, strain selection with Russet Norkotah was initiated by the Texas Potato Variety Development Program. Some 192 giant hill and/or tall type plants were selected from seedsmen and/or commercial Russet Norkotah fields in Colorado, while 183 were selected from commercial fields in Texas. Replicated yield trials with the final 13 of the original strain selections and Russet Norkotah were conducted in 1992, 1993, and 1994 in both Colorado and Texas. A mixed model analysis of variance was performed followed by disjoint cluster analysis in order to group strains into high, medium, and low yielding classes or clusters. Canonical discriminant analysis was performed to confirm the three clusters and to determine the extent to which various yield attributes are related and can be used to separate the three clusters. Several strains including TXNS (Texas Norkotah Strain) 112, TXNS 134, and TXNS 278 were identified as superior in Colorado, while TXNS 223, TXNS 249, and TXNS 296 were similarly identified for Texas growing conditions. These strains usually outyielded Russet Norkotah by 20–30%.     

Comparative effects of cut and treated seed tubers vs untreated whole seed tubers on seed decay, Rhizoctonia stem canker, growth, and yield of Russet Burbank Potatoes

Whole seed tubers have been reported to have performance advantages over seed tubers that have been cut, even if the cut tuber pieces are treated with a fungicide dust. For this study, whole seed tubers were compared to cut seedpieces and to cut seedpieces treated with four different commercial fungicide dusts for five consecutive seasons. A new field generation 3 Russet Burbank seed lot was used for each of the five years of this study. Both whole tubers and cut seedpieces were inoculated withFusarium spp., and the seedpieces were then treated with a fungicide dust. Inoculated and uninoculated untreated controls were also included. Emergence,Fusarium seed decay,Rhizoctonia stem canker, stem numbers, and vigor, as well as yield and grade data were obtained.Rhizoctonia stem canker in stems grown from whole seed tubers was significantly higher than in stems from seedpieces receiving fungicide treatment in several of the study years. Predicting whole seed tuber performance is difficult because performance varies more from year to year than performance of cut and treated seedpieces. Yield performance of whole seed tubers was not significantly better than cut and fungicide-treated seedpieces in any experimental year, and yield of large (over 280 g) tubers was significantly less than that recorded for two of the treatments when data from all five years were combined. This study demonstrated that untreated whole seed did not outperform cut and treated seedpieces for vigor, stem numbers, disease ratings, or yield in small plot comparisons for five consecutive seasons.     

GemStar russet: A potato variety with high yield, good culinary quality, excellent fresh market appearance, and resistance to common scab

GemStar Russet, derived from the cross Gem Russet x A8341-5, was released in 2004 by the USDA/ARS and the agricultural experiment stations of Idaho, Oregon, and Washington. The foliage of GemStar Russet is dark yellowish-green, spreading, with large leaves and abundant white flowers. The tubers are brown, medium to heavily russeted, oblong, with a slightly prominent eyebrow, white flesh, and indistinct pith. GemStar Russet was compared with Russet Burbank and Russet Norkotah in trials across the Pacific Northwest for yield, quality, and disease response. Except for locations in southern Idaho, in general, GemStar Russet produced slightly lower total yield than Russet Burbank, but much higher U.S. No. 1 yield. When compared with Russet Norkotah, GemStar Russet produced similar total and U.S. No. 1 yields in early harvest trials but higher total and U.S. No. 1 yields in late-harvest trials. When observed for defect problems, GemStar Russet exhibited resistance to second growth, growth cracks, and stemend discoloration, moderate resistance to blackspot and shatter bruising, but a high level of susceptibility to hollow heart. In product quality tests, GemStar Russet was rated superior to Russet Burbank for french fry quality and comparable for baked potato quality. GemStar Russet was found to be immune to PVX, resistant to common scab and powdery scab, moderately resistant to Verticillium wilt, tuber net necrosis caused by PLRV, and corky ringspot. It demonstrated susceptibility to late blight, PLRV, dry rot, soft rot, and ringrot and extreme susceptibility to PVY^o. Biochemical analysis of GemStar Russet tubers showed them to be higher in protein and much higher in vitamin C than those of Russet Burbank or Russet Norkotah. Three-year average for tuber glycoalkaloid concentration was 1.5 mg 100 g^?1.     

Umatilla Russet: A full season long Russet for processing and fresh market use

Umatilla Russet, a moderately late maturing variety especially suitable for frozen French fry processing but also acceptable for tablestock use (boiling, and baking), was jointly released by the Agricultural Experiment Stations of Oregon, Idaho, and Washington and the U.S. Department of Agriculture in 1998. Umatilla Russet was evaluated in irrigated trials in Oregon from 1988 to 1997, and in western regional trials from 1989 to 1991. Total yields were similar to those of Russet Burbank, but Umatilla Russet produced higher marketable yields. In three years of regional trials at up to 13 locations in seven western states, Umatilla Russet averaged 40.5 Mg/ha compared with 32.4 Mg/ha for Russet. Burbank. Umatilla Russet fry color and specific gravity are consistently equal to or better than for Russet Burbank. Umatilla Russet is less susceptible toVerticillium wilt than Russet Norkotah, less susceptible to net necrosis than Russet Burbank, and resistant to PVX. It is susceptible to PLRV and expresses foliar symptoms of PVY more clearly than Russet Norkotah. Umatilla Russet is less susceptible to tuber infection and decay caused byPhytophthora infestans than Ranger Russet and Russet Norkotah. Umatilla Russet is less susceptible to hollow heart, brown center, growth cracks, and sugar ends, but more susceptible to blackspot and shatter bruise than Russet Burbank